Advertisements

Greenland Melt Exceeds Summer Maximum in Early June. “Storms of My Grandchildren” on the Horizon?

greenland_melt_area_plotJun11

(Image source: NSIDC)

According to reports from NSIDC, Greenland ice sheet melt had exceeded average summer maximum values by Tuesday, June 11th, about a month and a half earlier than normal.

On Tuesday, about 24% of the Greenland ice sheet had experienced melting. This value is about 1% higher than the usual summer maximum of 23% melt coverage.

2013’s early, widespread melt follows just one year after melt covered nearly all the Greenland ice sheet for days during July of 2012. 2012’s melt was the strongest for Greenland in at least 120 years. For 2013 melt values to approach or meet 2012 melt values would further reinforce a powerful increase in Greenland melt that has occurred since the 1990s. Since that time, the rate of Greenland melt has more than tripled.

June 2013 has established a trend of rapidly increasing melt that sets in place conditions for past record values to potentially be challenged. As such, it is well worth monitoring conditions as they develop.

greenland_melt_nomeltJun11

(Visual of Greenland melt coverage on June 12th. Image source: NSIDC)

Scientists now are at odds over how fast Greenland melt will increase. Some believe a linear increase in melt is most likely while others believe that exponential increases in Greenland ice sheet melt are not out of the question. Should the increasing pace of melt for Greenland continue, powerful changes in the weather, especially for Europe and North America are in store. This winter and spring’s extreme weather over much of Europe may just be a foretaste of what is to come.

Storms of My Grandchildren on the Horizon

Massive melt from Greenland by or before mid-century means large volumes of fresh water in the North Atlantic. These high volumes of fresh water could substantially slow or even halt the Gulf Stream. Present measures of Gulf Stream circulation already show the current slowing. If these trends continue, the replacement of this warm water stream with cold water from Greenland will radically alter northern hemisphere weather.

The Weather Channel provided a brief summary of some of the possible impacts of slowing Gulf Stream currents here.

Even worse, under human caused climate change, a cooling of the North Atlantic occurs at about the same time tropical and temperate region temperatures begin to rapidly rise. This creates a high gradient between cold air near Greenland and warm air directly to the south. The result, according to models, is powerful storms never seen before in human memory.

In “The Storms of My Grandchildren,” NASA scientist James Hansen warned of the potential for frontal storms large enough to span continents and packing the punch of hurricanes. Is is just these kinds of storms that rapid Greenland melt combined with intensified warming at the tropics could set off.

The conditions for these events appears to be ramping up now and could be present, in the worst case, by as soon as the 2030s. In the meantime, weather conditions are likely to continue to deteriorate as a combination of sea ice melt and Greenland ice sheet melt play havoc with traditional weather patterns.

Alterations to the Northern Hemisphere Jet Stream as demonstrated by the work of Dr. Jennifer Francis is one such change that is already present. And this alteration has already resulted in several instances of enhanced severe weather.

Meanwhile, in more southerly regions, we find that the seasons for tropical storm development are lengthening. Dr. Jeff Masters of WeatherUnderground made the following statement in reference to the early June formation of Tropical Storm Andrea:

Andrea’s formation in June continues a pattern of an unusually large number of early-season Atlantic named storms we’ve seen in recent years. Climatologically, June is the second quietest month of the Atlantic hurricane season, behind November. During the period 1870 – 2012, we averaged one named storm every two years in June, and 0.7 named storms per year during May and June. In the nineteen years since the current active hurricane period began in 1995, there have been fifteen June named storms (if we include 2013′s Tropical Storm Andrea.) June activity has nearly doubled since 1995, and May activity has more than doubled (there were seventeen May storms in the 75-year period 1870 – 1994, compared to 6 in the 19-year period 1995 – 2013.) Some of this difference can be attributed to observation gaps, due to the lack of satellite data before 1966.

So storminess increases at the tropics and storminess increases at the poles. When these two conditions meet, the potential exists for amazingly powerful and freakish storms similar to, but even worse, than Hurricane Sandy. It is the potential of global warming to set in place conditions where powerful storms can combine, persist, and expand over vast areas that is a threat we must consider as Greenland melt continues to increase, Arctic sea ice melt progresses, and warming in the tropics and temperate zones continues to expand.

Links:

NSIDC

The Weather Channel Observes Slowing Gulf Stream

The Storms of My Grandchildren

WeatherUnderground

Masters: Hurricane Season Getting Longer

Advertisements

Persistent Arctic Cyclone and The ‘Warm Storm’ of 2013: How Unusual is It? Is Central Ice-Thinning Normal? What are the Worst-Case Scenarios?

(Edited on June 18 due to the availability of new information. I also want to promote two excellent blog posts related to this subject. One, by Neven, over at the Arctic Sea Ice Blog, takes a closer look at the science of Perstistent Arctic Cyclones, the other, posted on the Daily Kos by FishOutOfWater, links PAC 2013 to the collapse of the polar vortex this past winter.)

*******

Yesterday, two commenters — Sourabh in this blog post and T.O.O. in this blog post — raised some very salient questions about 2013’s Persistent Arctic Cyclone (PAC). These commenters wanted to know how critical to melting is PAC 2013, is this the first time we’re witnessing thinning of the central ice due to a long-period Persistent Arctic Cyclone, and by ‘what conditions could the central ice be expelled from the Arctic Basin?’

I posted a short response to their comments here and here. But I wanted to take the time to explore their questions in greater depth. Hence, this blog post.

Long Duration Summer Cyclones Rare, But Not Unheard of

First, let’s take a look at the current PAC 2013, its forecast duration, and how it compares to other storms. For context, it is important to note that most cyclones in the Arctic basin last for 40 hours or less. By comparison, PAC 2013 began on about May 26th and has remained in the Arctic for about 16 days. Forecasts now show the storm persisting until at least June 21rst. If the storm lasts this long, it will have remained in the Arctic for 26 days.

Another comparison can be seen in the Great Arctic Cyclone of 2012 (GAC). This storm was the 13th most powerful storm ever to impact the Arctic in the modern record. It lasted for about two weeks and reached a minimum central pressure of about 966 mb. The current PAC 2013, while lasting longer (and projected to last much longer) than GAC 2012, reached a lowest central pressure of around 975 mb while averaging in a range of 985 – 995 mb.

It is worth noting that Arctic cyclones are a year-round phenomena. And that more numerous, though somewhat weaker storms, have been noted to appear from May to July. That said, the strongest, longest duration storms usually occur during winter and can last for three weeks to a month or more. During summer, Arctic cyclones are weaker, pack less of a punch, and usually don’t last as long as winter storms. What makes PAC 2013 and GAC 2012 exceptional is the fact that they were both strong, long duration storms occurring during summertime and that they occurred under conditions of record thin Arctic sea ice.

There is some research to show that the strength of summer Arctic cyclones has been increasing since the late 1970s. These researchers show that increasing levels of moisture and higher temperatures around the Arctic during summer time have added fuel to the formation of new storms. Weather records do show the strength of the most powerful summer storms generally increasing with time.

Overall, PAC 2013, though somewhat weaker than GAC 2012 at peak strength, is projected to remain in the Arctic for a very long time. And with lowest pressures rivaling that of a moderate-strength tropical cyclone, it should continue to have substantial impacts — both to Arctic weather and to sea ice.

New Event: Storms that Melt Sea Ice

The Great Arctic Cyclone of 2012 was also unique because it was the first storm to have a major impact on Arctic sea ice. Though researchers have tended to disagree over how pivotal the storm was in reducing ice to the record low values achieved during 2012, it is generally accepted that the storm melted at least 250,000 square kilometers of sea ice during early August.

The storm achieved this feat by mixing the surface ice with warmer waters lying just beneath. Wave action and cyclonic pumping of warmer waters from the depths provided a powerful force for thinning and melting the surface ice. Though no direct research on sea ice volume losses due to GAC 2012 has been published, CICE images before and after the event speak to a major thinning as a result of the 2012 Cyclone.

Before:

GAC2012ThicknessBefore

After:

GAC2012ThicknessAfter

(Images From: US Navy)

Note the large areas of ice thinned into naught by the storm as it plowed through the East Siberian, Chukchi, and Beaufort Seas. A region of central ice was also noticeably thinned during the storm.

We can, therefore, say with some confidence that it is the ice thinning forces of the storm which caused the loss of 250,000 square kilometers of sea ice attributed to its impacts. But we can also say that a visible and, as yet, undetermined volume of ice was also lost and that this loss substantially contributed to 2012’s record low status.

A similar situation is now present during PAC 2013. Substantial thinning is now visible in all the sea ice monitors, especially on the Russian side of the North Pole. But this event is different from GAC 2012 in that is occurring during June, a period of time in which the ice is thicker and more resilient. A period of time when air and water temperatures are relatively cooler. As a result, no where near as much in the way of sea ice area losses can yet be attributed to PAC 2013. I say ‘yet’ because this storm appears determined to stick around for the long haul. So we may see major area losses arise as a result of its action.

In any case, it is worth looking at before and after thickness maps to determine the level of damage caused by PAC 2013.

Before:

PAC2013Before

During:

PAC2013After

After?

PAC2013Jun18

(Images From: US Navy)

As is plainly visible from the above set of images, PAC 2013 has dramatically hollowed out the central sea ice. With at least another ten days of duration expected, we are still just in the preliminary phase of impacts. These should ramp higher as the days continue to progress. (Note, the last image was added on June 18th, two days prior to a possible cessation of the storm).

Both PAC 2013 and GAC 2012 are new events for the reason that they result in melt and weakening of sea ice. This is unprecedented because past storms did not generate measurable losses in summer (You can look at some of this research here and here). To the contrary, it was thought that the cloudier, cooler storms were generally protective. And this was true in a cooler climate. Now, strong storms have a potential to result in losses. And this new feature is an environmental condition brought about by human-caused climate change.

Is This the First Time We’re Witnessing A Summer Cyclone Thin the Central Ice in June?

Now that we have a little background on summer cyclones and how climate change has enabled them to both significantly thin and melt ice, we can confidently answer the question: is this the first time we’re witnessing a summer cyclone thin the central ice in June?

The short answer to this question is: yes.

In the satellite record, there is no precedent for a June storm melting and weakening the ice in the past. Though June storms have impacted and fragmented the ice before PAC 2013, this storm is the first powerful, long-duration event to have such a large, measurable melt effect in early summer. As noted above, past storms were thought to be defensive, resulting in a more resilient ice pack and less melt, overall, come end of summer.

In part, such widespread damage is due to the fact that the area currently influenced by the storm is so large — covering all of the Central Arctic. The other reason is the fact that the ice in this key region is supposed to be the most resilient to late summer losses. Instead, in early summer, we see damage and erosion.

Were the storm to end now, it would leave the central ice thinner and weaker to the assaults of late summer. But the storm hasn’t ended. It continues to churn and thin the ice even as temperatures rise.

It is possible that, if this storm lasts long enough, remains strong enough, and pulls in enough warm air, it could produce a large region of open water at the very center of the ice pack even as it shoves a large portion of the thickest ice toward the Fram Strait. Such an event would not only be unprecedented. It could be catastrophic.

Under What Conditions Could the Central Ice Be Expelled From the Fram Strait? Short Answer: Persistent, Warm Storm

So now we’ll address the nightmare scenario for this particular event. This expose is by no way a prediction. It is just an illustration of what the worst case, in this event, could look like. It is also, by no means, the only way we could lose all or most of the central ice. The ice, for example, could melt out under a sustained assault from the sun. The central ice could take a hit from a swift, powerful storm, then melt as warm air and sunlight moves in behind it. We won’t examine these and other cases. Instead, we’ll take a look at the worst case in the event of a long-lasting Persistent Arctic Cyclone that warms and churns throughout a good portion of summer.

The event could look something like this:

The Persistent Arctic Cyclone that emerged in late May continues on through June and into July. As the Arctic warms, more above freezing temperatures get wrapped into the storm. Eventually, much of the region it covers warms to a range of 0-6 degrees Celsius. Rain becomes a primary form of precipitation in the storm.

The added moisture, warmer cloud cover, and above freezing precipitation create a constant surface stress to the ice. Underneath, the constant churning pushes water temperatures above freezing due to an ongoing mixing of the cold surface layer with deeper, warmer waters. The combined result is an ice melting and thinning machine. By the end of June, a growing region of open water (concentration 20% and less) has emerged.

The open water is a breeding ground for powerful waves and a magnet for sunlight streaming down through periodic breaks in the clouds. This region of warmer water thrashes and bores through the ice as July advances, creating a pheonomena never before seen in the Arctic — a large, central region of open water surrounded by thinning ice. The result is ice edge melt occurring at the same time as central ice melt. From the cored out portion, an arm of open and or nearly open water begins to sweep around the Arctic, clearing away ice in its path. The arm extends to weakest areas of sea ice. A most likely candidate for this arm’s development is the Laptev Sea as there ice there has been weakest since start of melt.

These three factors would be devastating enough. But a fourth factor provides the coupe de grace: Fram Strait export.

The constant counter-clockwise motion of our warm storm has been shoving at the remaining thick ice anchored on Greenland and the Canadian Arctic Archipelago since early June. Increasingly, large volumes of thick ice are flushed out the Fram Strait. By end of June, as much as 10% of the thick ice has been exported. But this is just the beginning.

During late June and early-to-mid July, warm air invasions from the south have melted and thinned the Canadian Arctic Archipelago ice. Now thinning and fractures from this warming have advanced into the thick ice, weakening its anchor. During July, there is less resistance to the storm’s counter-clockwise motion so more and more thick ice ends up meeting its end through the Fram Straight.

By early August, the storm has lasted for an excessive period — nearly seventy days. But it still churns on, fed by an endless procession of storms and injections of warm, moist air from the south. In a final explosion of weather never before seen in the Arctic, much of the remaining thick ice is ejected, melted, or churned beneath a storm-tossed Arctic Ocean. By early September, the storm finally disperses, but little or no ice remains.

Conclusion

The above ‘Warm Storm’ scenario is pure speculation. We have no reason to believe the current PAC 2013 will last so long or will have such powerful effects. More likely, a still damaging but more moderate erosion of central sea ice combined with an enhanced Fram Straight export will occur. Should the storm last until the end of June, these damaging impacts will be more than enough to weaken the ice.

That said, should the storm last longer, then we will have an altogether unwelcome opportunity to test this ‘Warm Storm’ theory.

So we come at last, to answering the first question of our commenters:

How critical to melting is PAC 2013?

And the answer to this question will depend on the duration of the storm, its relative strength over time,  how much warm air is injected into it over the course of its life-span, and how much warm water it is able to dredge up from beneath it. At the very least it has already played a major part in early season melt. Should it last for a long duration, the story of 2013 melt may well become wrapped up into that of this particularly anomalous storm.

Links:

On Persistent Cyclones

Arctic Cyclones

Northern Hemisphere’s Polar Vortex has Collapsed Creating Persistent Polar Cyclone

2012 Arctic Cyclone

GAC 2013: Detachment

The Great Arctic Cyclone of 2012

August Arctic Cyclone was the Strongest Summer Storm on Record

The Summer Cyclone Maximum over the Central Arctic

Dramatic Inter-annual Changes of Perennial Arctic Sea Ice Linked to Abnormal Storm Activity

Powerful Arctic Cyclone Driving Record Sea Ice Melt

Arctic Cyclone Hangs On

The Big Thin Begins

US Navy

410,000 Square Kilometers of Sea Ice Lost in Two Days: Persistent Arctic Cyclone Weakens Heart of Ice, Rapid Edge Melt Devours Fringe

According to Cryosphere Today, Saturday’s Arctic sea ice area measured 10.22 million square kilometers. By Monday, that number had dramatically fallen to 9.81 million square kilometers. This loss of 410,000 square kilometers over the course of two days is extraordinarily rapid, even for a time of year when melt has tended to accelerate. On sea ice area graphs, it makes the last few days look like area numbers fell off the edge of a cliff. (Note that Cryosphere Today area numbers usually lag by a few days. So what we’re actually seeing is area measurements through Friday, June 7th).

Up until recently, sea ice area melt had been relatively moderate. But now, after a week of consistent 100,000+ square kilometer daily losses, and two days of 200,000+ losses, sea ice area is only a smidge above that of record melt year 2012 on the same day in June. In total, more than 800,000 square kilometers were lost over the course of the past week. This melt rate, if sustained, would render the Arctic ice-free by late August. If we look at past records, it is not likely that these rates of loss will continue. But past records may not prove a good guide in the current age of fragile Arctic ice. It is quite possible, given the ice’s fractured, frail, and mobile state, that such enormous melt rates, in the worst case, could be sustained or even exceeded. In this event, we would witness a total collapse of Arctic sea ice by the end of this year. So should current dramatic melt rates be sustained or worsen, we may be upping our forecast chances for near total melt by end 2013 (still at 10%).

In any case, warnings that we were not out of the woods after a slower than expected melt during May, seem to have born out in spades.

Persistent Arctic Cyclone + Rapid Edge Melt = Brutal Combination

The twin forces driving this sea ice loss are the Persistent Arctic Cyclone of 2013 (PAC 2013 — I’ve decided to keep this name. Neven has sanctioned it, even as he playfully recommended calling it Rocky Balboa, which would be entirely appropriate for this dogged storm.), which we began warning about on May 30th in The Big Thin Begins, and a rapid edge melt that also began in early June.

PAC 2013 has, for more than two weeks, been invoking a number of forces detrimental to sea ice in the Central Arctic. It has pulled warmer water up in a column beneath it, melting the bottom ice. It has, through cyclonic action, dispersed the ice away from its center of circulation. And, via energetic storm winds, it has churned and disturbed the surface waters just beneath the ice or at the surface, creating a mixing action that also erodes the ice.

Together, these forces have dramatically reduced the Central Arctic Sea ice. Sea ice thickness, according to the US Navy, after already thinning somewhat, looked like this on May 30th:

CICE2013

Today’s most recent measure shows the central ice pack suffering substantial reduction since that time:

arcticictnnowcastJune9

Note the major thinning in a region of the thickest ice even as thinner regions closer to Siberia ablated further over the past ten days.

Cracks visible in the Lance-Modis satellite shots confirm an increased breaking of the sea ice even just north of the Canadian Arctic Archipelago, where the ice is thickest. Through a combination of bottom melt and sea ice dispersal, it appears that a broad region of this ‘most resilient’ ice lost between .5 and 1 meter worth of sea ice over the past ten days. By June 6th, these losses began to show up in the, less sensitive, Cryopshere Today concentration graphic. By June 8th, a large swath where sea ice concentration had dropped to between 60 and 70 percent was indicated in the region most affected by PAC 2013:

CTconcentrationJun8

(Image source: Cryosphere Today)

Note the large swatch of red running directly through the Central Arctic. That’s a broad region of ice thinned by our Persistent Arctic Cyclone showing up in the Cryosphere Today measure.

Today, the cyclone has shifted toward the Laptev Sea and is dramatically churning the thinner ice there, shifting its special brand of havoc closer to the Siberian coastline. We’ll discuss more about this new development in an upcoming PAC 2013 forecast.

As PAC 2013 churned through the Central Arctic, melt accelerated at the ice periphery. In the Canadian Archipelago, large regions of ice turned a characteristic shade of blue as melt lakes developed and insolation began to do its work there. Both Hudson Bay and Baffin Bay also saw dramatically increased rates of melt. This larger region of the Canadian Arctic saw a powerful influx of higher temperatures. A pulse of warmth that likely pushed melt faster. Temperatures of 10-20 degrees Celsius became a common event near Hudson Bay and southern portions of the Canadian Archipelago. Above freezing temperatures stretched far northward, driving deep into the Beaufort Sea.

Across the Arctic Ocean, the Laptev Sea began to melt at a faster pace even as a region of the Chukchi Sea displayed a dramatic and rapid disintegration of sea ice. You can see this rapid melt by comparing the Lance-Modis image from June 2nd to today’s Lance-Modis shot of the region:

Bering Melt Start

This is what Chukchi Sea ice looked like on the 2nd of June (Image source Lance-Modis).

Bering Melt End

And here is what it looks like today (Image source: Lance-Modis)

Note the clearing of most ice from the Bering Straight even as the ice edge retreated northward toward an increasingly fractured and thinned polar ice cap. As warmer air is expected to enter the Chukchi over coming days, it appears that conditions will continue to favor rapid edge melt there.

Weather model forecasts also show warm air flooding into many regions at the ice edge, growing especially prominent in the Beaufort, Chukchi, and East Siberian Seas. Meanwhile, PAC 2013 is expected to continue to churn through the Central Arctic. These conditions are now projected to persist until at least June 20th, at which point our Persistent Arctic Cyclone will have lasted nearly a month.

As noted above, this combination of conditions: warm air invasion at the ice edge, historically thin, fragile, and mobile sea ice, and a Persistent Arctic Cyclone (PAC 2013) are likely to continue to promote rapid to very rapid melt in the Arctic as June continues to advance. Though 200,000 kilometer per day sea ice area loss is extraordinarily rapid and dramatic, the potential exists for single day losses to exceed even this highly radical number. A sea ice cliff for June 2013, thus, appears to be a distinct potential.

Links:

US Navy

Cryosphere Today

The Arctic Ice Blog

Lance-Modis

 

Cracks in Sea Ice Visible At North Pole Camera 1

CracksNorthPoleCAM1

(Image source: APL)

Small leads (cracks) in the sea ice became visible at the North Pole Observatory’s Camera 1 today.

This camera is part of a North Pole environmental observatory supported by a National Science Foundation Grant and managed by the Applied Physics Lab at the University of Washington. Camera 1 is one  of two cameras placed on ice at or near the North Pole to visually observe conditions there.

The cracks began to appear at around 20:15 this evening when two areas of ice — one to the left of the camera and one to the right — began to break up.

Ice near the North Pole is generally very stable. But melt over the past few years has begun to threaten melt in this region. Over the past two weeks, a persistent storm has churned up the ocean, breaking large sections of fragile ice. Unless conditions remain colder than average for much of the summer this year, large sections of ice, previously protected from melt, are at risk of loss during this summer.

Some scientists, noting rapid trends in sea ice area and volume loss, have recently warned that Arctic sea ice could completely melt by end of summer as early as 2015 and possibly before 2020. An indication that this end stage melt was beginning would be cracking and break-up of ice in the area of the North Pole and in other protected regions close to Greenland and the Canadian Arctic Archipelago.

Summer 2013 is not expected to see all or most sea ice lost by end of summer. However, an extraordinarily strong melt year with losses akin to 2007 or 2010 (volume) would be enough to render the Arctic mostly ice free.

Links:

North Pole Observatory

Persistent Arctic Storm

Storm Thins Sea Ice: Most Sea Ice Monitors Now Show 2013’s Persistent Arctic Storm’s Dramatic Impact

Over the past two weeks a storm has raged through the Arctic, churning and thinning the region’s thickest, most resilient sea ice. Now, almost all major measures show a dramatic thinning of the central ice even as warmer air has been funneling into the region. Models still show storm conditions continuing until June 17th. So the ongoing thinning and churning this storm has produced is likely to continue even as the region steadily warms.

Name Change to Persistent Arctic Storm 2013

The storm that has now plagued the Arctic for two weeks has recently involved numerous low pressure areas. For this reason, it is appropriate to change its name, since multiple low pressure systems, rather than a single consistent cyclone, are involved. So, going forward, we will be calling this event: Persistent Arctic Storm 2013 (PAS 2013).

Pressure Levels Rise Somewhat

Today, we can see a double barrel low pressure system still hovering over the central Arctic:

PAS2013pressureJune7

(Image source: DMI)

Pressure levels are up somewhat, now showing about 995 mb in two low pressure centers flanking the North Pole. Forecast models show the storm remaining in the 985-995 strength range all the way out to June 17. These models have tended to show the storm hovering closer to Svalbard, the Kara and Laptev seas over this period as warmer air filters in and builds over the region of the Beaufort Sea and East Siberian Arctic Shelf. These models can be subject to quite a bit of change, so we’ll have to keep a close eye for any alterations.

Tomorrow’s forecast is for the double-barrel low to recombine over the North Pole and drop to 985 millibars. It’s important to note that 985-995 is still a moderately strong storm. By comparison, Tropical Cyclone Andrea bottomed out at 997 millibars before dumping 10 inches of rain and sending 2-5 foot storm surges over portions of coastal Florida. So this particular storm, with a strength ranging from 975 to 995 millibars over much of its life contains a substantial amount of energy. It is also worth noting that quite a bit of warm air is lurking around the storm’s periphery. This air could boost the storm if conditions favor an influx of warm, moist air.

Dramatic, Widespread Thinning Now Visible in Most Sea Ice Monitors

It’s becoming more and more clear that this storm’s energy has gone to work in significantly eroding the Arctic’s central ice. Now, almost all sea ice monitors are showing dramatic impacts on sea ice in and around the Central Arctic Basin.

arcticictnnowcastPAS

(Image source: US Navy)

The US Navy’s CICE/HYCOM thickness model now shows substantial thinning and divergence in two regions of the central, thick ice. The region closer to the Russian side of the Arctic has persisted for about a week now and is confirmed in the other measures below. The second region, closer to the Canadian Arctic Archipelago is newer. So we’ll have to look for persistence there. Overall, the remaining thick ice is in a much worse state in this monitor than it was last week.

UNIBREMENPAS

(Image source: Uni-Bremen)

Uni-Bremen has also shown persistent and growing thinning in its surface ice concentration monitor. Now, many regions where the storm passed are showing surface concentrations of 75% or less. These features have continued to grow more prominent as ice in the Central Arctic thinned over the past week. In contrast to the US Navy’s CICE/HYCOM thickness model, this Uni-Bremen model measures surface concentration while CICE models thickness.

Loss of surface concentration is the final result of thinning. But thinning tends to occur before losses in surface concentration are visible.

Arctic_r04c04.2013158.terra.1kmPAS

(Image source: Lance Modis)

A few breaks in the clouds have also opened up over the Central Arctic. These gaps confirm what both Uni-Bremen and CICE are showing. In the most recent Lance-Modis shot, we have visual of a dramatic Central Arctic thinning. In the upper left hand corner, note the large region of thinned and broken ice. This visual shot shows that the thinning and loss of concentration seen in the other measures bears out in reality. (So yes, Neven, it increasingly appears that this is quite real.)

Together, these measures provide growing evidence that the central Arctic sea ice has taken a substantial blow.

More rapid decline in sea ice area and extent during storm

As the central ice thinned and dispersed during this month’s Persistent Arctic Storm, sea ice area and extent also rapidly dropped off. Both Cryosphere Today and JAXA showed area and extent falling at rapid rates over the past week. Weekly extent declines for JAXA is in the range of 400,000 square kilometers, dropping back to 2012’s lower levels. Cryosphere Today sea ice area losses were also rapid — in the range of 500,000 square kilometers. But sea ice area, according to Cryosphere Today, remained above 2012 levels.

Sea_Ice_ExtentPAS

(Image source: JAXA)

Some had asserted that this storm would result in ice formation, not loss. But visual, concentration, and thickness monitors show that just the opposite occurred. Furthermore, increasing (not slowing) pace of sea ice loss in both area and extent measures confirm the likelihood that this Arctic storm hastened sea ice erosion, melt, and volume loss during early June.

This Storm’s Story Isn’t Over Yet

Needless to say, this storm’s story isn’t finished yet.

Associated with its circulation was the influx of above-freezing temperatures into the Central Arctic. You can see this area  in the DMI temperature measurement below:

temp_latestPAS.big

(Image source: DMI)

Note the swath above freezing temperatures hovering near the region of East Siberia. This area is a remnant of warm air pulled up from the Scandinavian heatwave earlier this week. It has now transitioned to its new location where models expect above-freezing temperatures to amplify over the coming days.

By Wednesday of next week, model runs show a large influx of above freezing average temperatures expanding over this half of the Arctic Basin, while a still respectable 990 millibar Persistent Arctic Storm continues to chew away the sea ice on the Svalbard side of the North Pole. Storm rotation is also shown to pull in 5+ degree Celsius temperatures into the region of the Kara and Laptev seas. By June 17, the model looks like this:

Arctic Forecast Persistent Storm Impacts

(Image source: ECMWF)

Our storm still persists, centering now over Svalbard and the Kara Sea, while warm air is shown to engulf and invade the Arctic .

So it appears that from all sides warmer air continues to encroach and get wrapped into this storm. Such conditions are likely to further enhance rapid melt and thinning of the sea ice. Should these conditions, as projected in the ECMWF models, bear out, it is likely we will continue to see a melt acceleration over the next ten days. The higher temperatures, the action of the persistent storm in the central Arctic, and the already observed thinning of sea ice there are indications that melt may well already be on its way to a rapid ramp up.

Conditions remain very dynamic and unstable with the likelihood of dramatic melt increasing as time moves forward.

Links:

The Arctic Ice Blog

DMI

US Navy

Uni-Bremen

JAXA

Cryosphere Today

Lance Modis

ECMWF

Greenland Ice Melt Accelerates in Early June

greenland_melt_earlyjune

(Image source: NSIDC)

After a warm winter, the spring that followed has been a cool one for Greenland. An upswing in the jet stream that had warmed Baffin Bay and the western coast of Greenland through early April faded and ice sheet melt through May has been slower than average.

But over recent days warmer air has moved into Greenland, melting ice along its coastal edges. This warm air influx was driven, in part, by a heat-wave in Scandinavia that then spilled warmer air over the North Atlantic and into the Arctic. This region of warmer air also invaded parts of the northeast coast of Greenland.

As temperatures increased, so did melt rates. By June 4, pace of melt was again well above average.

greenland_melt_june4

(Image source: NSIDC)

Melt occurred most intensely along the eastern and northern coasts with lesser amounts showing along the edge of Baffin Bay. Overall, about 15% of the Greenland Ice Sheet was showing melt by June 4.

2013 Compared to Past Years

During 2012, record summer heating caused the entire Greenland ice sheet to melt for some days during July. This kind of melt hasn’t been seen for over 100 years but many scientists are now predicting that 2012 melt paces could be seen as often as twice per decade or more.

And Greenland’s pace of melt is accelerating. During the 2000s rate of Greenland ice melt is five times that of the 1990s. During the past 20 years, Greenland has melted more than in any comparable period during the past 10,000 years.

That’s not to say that every year will be a record year like 2012. At this point, there’s no way we can tell if 2013 will meet or exceed Greenland’s melt during summer a year ago. Usually, it’s not the case that you get back to back records.

So far, the weather pattern hasn’t been as conducive for Greenland melt this year. But, lately, the Arctic has been very unstable and the weather rather unpredictable. So it’s worth keeping a close eye to Greenland as summer progresses.

Links:

NSIDC

Polar Ice Sheets Melting Faster Than Ever

Greenland, Antarctic Melt Speeding Up, Study Finds

Persistent Arctic Cyclone of 2013 (PAC) Returns to Trouble Central Arctic, Cloaks Itself in Warmer Air, Strengthens to 975 Millibars

CycloneNorthPoleJune5

(Image source: DMI)

Today the Persistent Arctic Cyclone of 2013 (PAC), re-centered over the North Pole even as it wrapped itself in above-freezing temperatures.

The above image shows a double barrel low roughly centered over the North Pole with a second low adjacent to the Canadian Arctic Archipelago. Lowest pressures remain around 980 mb — a rather potent storm for early June. Though not likely to grow as strong as the Great Arctic Cyclone of 2012 (GAC), this particular storm has now lasted for nearly two weeks and is projected to remain in the Arctic at least until June 15. Such persistence is likely to make this storm a substantial factor in the ongoing melt season.

Yesterday, the storm drew warm air in from the south behind it. This influx of warmer air ran into the Central Arctic beneath a train of cloud over a region near Svalbard and was visible in this Lance-Modis satellite shot. Temperatures in the region of Svalbard rapidly warmed with some regions there reporting 50 degree temperatures today — a virtual heat-wave for Svalbard this time of year. An area of dispersed ice near Svalbard also suffered very rapid melt yesterday, likely a result of this flood of warm, moist air.

Regions near the North Pole now show near freezing and above freezing temperatures. The storm backed into this warmer air, becoming wrapped in it as it returned to the Central Arctic. You can see this plume of warm air on the storm’s right flank in the DMI image below:

ArctictempsDMIJune5

(Image source: DMI)

This above-freezing air now resides over a region where sea ice remains broken and churned by previous passages of this storm. This region is heavily obscured by dense cloud cover. However, we can get a few peeks down through the clouds in the latest Lance-Modis shot of the region. What detailed inspection reveals is the ghostly image of shattered ice with large, dark gaps of ocean water between. These gaps have likely emerged through the physical process of storm winds diverging the ice as cyclonic forces churn the protective, cold top layer of water with warmer layers underneath.

This assault from below is now enhanced by the fact that near freezing and above freezing air has moved in overhead (seawater melts at around 29 degrees Fahrenheit).

A close look at the image below reveals these gaps:

Arctic_June5gaps

(Image source: Lance-Modis)

The clouds in this image are quite thick. However, if you took slightly to the left of direct center, you’ll be able to see ghosts of the fragmented ice and large gaps beneath.

The US Navy’s most recent CICE model run shows the PAC delivering a sustained blow to the thick ice just north of the Canadian Arctic Archipelago (CAA) before impacts are again projected to increase over coming days in the Central Arctic. Note the shifting of yellows and reds to greens and blues near the CAA. This is indicative of a loss of about a meter or more of sea ice thickness in this region. Also note the more wide-spread thinning that is expected to re-emerge near the North Pole as light blues in the model run fade more toward darker blues, showing about an additional half meter loss there.

arcticictn_nowcast_anim30dJun5

(Image source: US Navy CICE)

Confirmation will be necessary both visually and in other measures in order to verify the losses shown in CICE. Early losses were confirmed in Uni-Bremen, Lance-Modis visuals, and JAXA. However, dense cloud cover is currently making confirmation difficult even though some hints of this ongoing damage are visible through the clouds.

As mentioned yesterday, the primary processes for melt occur through divergence of the sea ice as well as via churning, upwelling, and Ekman transport of warmer water up from the depths. Today, melt potential is added via near and above freezing air temperatures over large regions of the Central Arctic. And as we’ve been warning since last Friday, the sustained nature of this storm has the potential to severely weaken the Central Arctic ice just prior to the warmest days of summer.

Since yesterday’s May PIOMAS update we’ve had more news to consider. However, apparent central ice impacts from this storm didn’t begin to seriously ramp up until the start of June. So we may need to wait to end of June for more clarity on total impacts. Nonetheless, all indications are this storm continues to fling the sea ice about quite a bit, with CICE continuing to show significant impacts to central ice thickness.

So, for now, the big thin continues.

UPDATE:

Warm, moist air influx from the south appears to have provided this storm with some added intensity. What, earlier, was a double barrel low pressure system has now combined, drawing warmer air toward its center as its intensity increased to around 975 mb. Now this storm is just about 9 mb shy of the Great Arctic Cyclone of 2012’s maximum intensity. In any case, 975 mb is a very respectable storm.

You can take a look a the latest storm intensity map here:

Arctic Cyclone Intensifies

(Image source: DMI)

UPDATE:

ECMWF weather forecast model runs for June 14 show PAC 2012 deepening to a 965 mb low pressure system. Should this strengthening occur, the system will have become stronger than the Great Arctic Cyclone of 2012. With the storm lasting so long, if it reaches such a strength, we may be dubbing it the Persistent Arctic Megastorm 2013 (PAM). Definitely something to keep an eye on.

PIOMAS Volume Melt Slowed in May, Too Soon to Implicate Negative Feedbacks.

A slowing in sea ice area and extent melt during May has born out in the PIOMAS volume numbers. According to the most recent PIOMAS update, pace of Arctic sea ice volume melt remained about level during mid-to-late May. In past record melt years, 2011 and 2012 volume melt picked up by the end of May.

2013’s end May melt, however, was more gradual:

PIOMASmay2013

(Image source: PIOMAS)

As a result, sea ice volume has edged away from record low territory and is currently the third lowest in the measure.  It’s a number still quite close to record lows, sitting about 900 cubic kilometers above 2012 values. But closer yet is 2010, the 4th lowest year, which was about 200 cubic kilometers above 2013 by end of May.

Overall, Arctic sea ice volume is a bit more substantial, but still low enough to be worthy of concern. The reason is that, as noted before, the disposition of Arctic sea ice this year is, overall, thin and spread out. PIOMAS shows overall ice thickness just slightly above record low values. While Arctic Ice Blog Neven’s crude ice thickness calculator that simply divides PIOMAS volume by Cryosphere Today area shows ice currently at its thinnest on record:

Neven Ice thickness

(Image source: Neven)

It is also worth pointing out that Greenland and the Central Arctic above the 80th parallel has been somewhat cooler than average this May, despite large regions of substantial warming present in other areas. Whether this trend persists and whether it has an impact on melt for 2013, will be more readily apparent as June progresses.

Emergence of negative feedbacks?

A prolonged slow-down in sea ice volume melt would also begin to beg the question: have negative feedbacks started to emerge in the Arctic? Large influxes of fresh water from Greenland have been flushing into the Arctic since the early 2000s. So one wonders if such high volumes of cold, fresh water could be involved in rejuvenating the Cold Arctic Halocline (CAH) layer while at the same time pumping colder water into the North Atlantic.

This layer of cold water is a key protector of the Arctic ice pack. Over the past few decades, the CAH has been undergoing dramatic retreat. Its retreat is a primary reason why the sea ice is so vulnerable to impacts from a warming ocean beneath. (A number of scientific papers have been written on this subject. The Response to Climate Change of the Cold Arctic Halocline, Shielding Sea Ice from the Warm Deep Water Below is just one example.)

In the Antarctic, scientific research has shown that glacial melt on the Antarctic continent has provided a cold layer of protective water which, in turn, has made the sea ice more resilient there. So if 2013 melt does slow and we get a trend of slower sea ice melt years to follow, it will be worth investigating if such a negative feedback is currently active in the Arctic.

Evidence of Negative Feedbacks in Paloeclimate

An increasing pace of northern hemisphere ice sheet melt has also been implicated in past climate swings. The Younger Dryas period occurring about 12,000 years ago was initiated by the breaking of an ice damn in the Laurentide ice sheet which covered a large portion of North America. This ice damn collapse flooded cold water into the North Atlantic which initiated major swings in climate — setting off a period of colder temperatures that lasted for about 1,000 years.

Geological observations of such a large infusion of cold, fresh water provides an example of how large volumes of melt water can act as a negative feedback and cool the climate. Present day Greenland melt is substantial, averaging about 500 cubic kilometers per year, though certainly not as substantial as what occurred during the Younger Dryas. Nonetheless, Greenland and Canadian Arctic Archipelago glacial melt is likely to have an impact on both sea ice and climate as melt rates increase.

This will be something worth looking at if volume melt continues to slow and cooler conditions begin to persistently crop up in the Arctic. At some point, human greenhouse gas forcing is likely to achieve such an event. When this happens, Arctic temperatures are expected to cool even as warming increases in the lower latitudes. The weather consequences for such an event are quite dramatic (a subject worth exploring in another blog).

All that said, the above is purely speculative and we would have to see a more consistent slow-down in volume melt as well as a regime of cooler Arctic temperatures to validate such an occurrence.

Not out of the Woods Yet

So it is worth emphasizing that we are not out of the woods yet. One month of slower than blindingly fast volume melt in the context of some of the thinnest ice on record does not a trend make.

More ice volume remains in areas outside the Central Arctic Basin and so will be more vulnerable to mid-to-late-season melt. In contrast, Central Arctic ice is much thinner than usual, also making it vulnerable. So volume numbers will be more telling once we start getting substantial melt in Hudson Bay, Baffin Bay, and the Kara Seas. Speculation for a major June melt, for various reasons, is running particularly high (An interesting and well-thought-out take is that of Chris Reynolds over at Dosbat.).

This fragile state makes end of June PIOMAS numbers an important indicator. If temperatures are cool, the edge ice stays more resilient, the central ice is able to hold together under the pounding of our Persistent Arctic Cyclone (PAC) of 2013, and the pace of overall melt remains slower as volume numbers remain somewhat higher by end of June, then it becomes a bit less likely we will see another record year in 2013. Were such an event to occur, we’d have to revise our end-of-year melt risk estimate downward.

We are still in record low territory. June is a volatile month. And we have the PAC of 2013 as well as the potential emergence of warmer waters from the depths to contend with. So June is likely to be a very, very interesting month.

The Big Thin Begins: Week-Long Cyclone Chews Away Fragile Arctic Sea Ice

cyclone-arcticictn_nowcast_anim30d

(Image Source: CICE)

A moderate-strength cyclone that emerged about six days ago and is expected to last at least until Monday is slowly chewing away a large area of Arctic sea ice near the North Pole. Cyclonic action generated by the storm is now resulting in an unprecedented thinning of central Arctic sea ice. It is important to note that should this ice thinning continue, it could have major impacts on end summer sea ice this year.

The low that is causing the trouble moved out of the region of the Beaufort Sea, skirted East Siberia and had transitioned into the central Arctic Ocean by about May 24th. Since then, it has persisted, remaining nearly stationary with a slow drift back toward the Beaufort. Forecast maps show the low remaining in this region until at least Monday before it weakens and moves toward the Mackenzie Delta. Strangely, long-rage forecasts show it re-strengthening even as it returns to the central Arctic.

Arctic cyclone

(Image source: DMI)

Minimum central pressure continues to hover around 990 millibars. This moderate strength compares to the much stronger Great Arctic Cyclone of 2012 which bottomed out around 960 millibars. However, the storm is quite strong for this time of year, when Arctic cyclones tend to be rare and weak, containing enough energy to generate winds that erode sea ice.

This erosion takes place via a pumping process by which the ice is pushed against the ocean surface by the cyclonic wind field. This motion, in turn, stirs up the underlying waters creating a warm, upwelling current. Since the forces occur over broad regions, powerful surface forces allow the upwelling to dredge deep, causing mixing between surface and lower layers. Tendrils and micro-currents of warmer water thus rise to contact the ice. This action can melt the sea ice from below, breaking it into smaller chunks, opening polynas, and riddling the ice with leads. If the storm grows strong enough, large wave action can devour whole sections of ice. But, in this case, the storm does not appear to be powerful enough to generate this kind of wave action.

Since 2012, we have already seen two major upwelling events. One, already mentioned, was the Great Arctic Cyclone of 2012. The second, involved strong off-shore winds during February and March which pushed ice away from shore and, in the region of Barrow Alaska, resulted in near-shore upwelling that temporarily melted ice even as it was pushed out to sea. The combined result was open water during winter.

We can see the storm’s current and projected impacts on the CICE model run posted at the top. CICE is projecting the development of a large area of thin and fractured ice near the North Pole in the storm’s wake even as a region of thick ice north of the Canadian Arctic Archipelago erodes. These projections show average thickness in a wide region falling from about two meters to less than one meter.

That’s very thin ice for North Pole regional waters.

Already, some impacts from the storm are visible in Lance-Modis shots of the region.

Arctic_r04c04.2013150.terra.1km

(Image source: Lance-Modis)

In the above shot, we can see the center of our moderate-strength cyclone near the middle-left portion of the image. To the right of the storm center, we can see down through the clouds to areas where the ice has fractured, revealing the dark blue waters beneath. Below the storm center and near the lower left-hand corner of the image is the North Pole. So what we are seeing is a broad area of leads and fractured ice with gaps measuring up to about 5 km wide within 200 miles of the North Pole. This kind of development is not at all usual for late May, much less late August.

CICE model runs show ice in this region continuing to thin, fracture and weaken as the storm passes.

As the storm moves away, it is expected to pull warm air in behind it, which could further weaken the ice. ECMWF weather forecasts show this warm air influx occurring by about June 4:

WarmairRecmnh1202

(Image source: ECMWF)

In the above image, we see 5 degree C temperatures plunging directly into the heart of the Arctic. A powerful late spring event should it emerge.

In the past, storms of this kind have had very little impact on sea ice. However, this year the ice is very thin and spread out. Most ice in the Arctic is showing a thickness of two meters or less. Records of past melt seasons show that two meter or thinner ice is unlikely to survive the melt season.

Furthermore, packs of much warmer air are drawn closer to the Arctic center by a wavy pattern in the jet stream. The result is that large north-south swoops draw warmer air up from the south even as they push Arctic air into more southerly regions. Europe, in particular, suffered due to this mangling of the jet stream. Ironically, a growing body of scientific evidence shows that these very changes in the jet stream are a result of loss of sea ice. So it appears that loss of sea ice is resulting in a snow-balling of forces that contribute to its ultimate demise.

The ultimate result is an Arctic-wide ice thinning impacting even the most central and protected areas. Even in this region of the central Arctic, where ice is usually much thicker, large regions of 2 meter or thinner ice dominate. You have to venture closer to Greenland and the Canadian Arctic Archipelago to find areas of ice thicker than 2 meters. However, as the recent evacuation of a Russian Arctic Expedition in that region shows, even the thickest ice is far more fragile than before.

The result of all this thin and broken ice is that it is much more vulnerable to surface conditions. A storm moving over thin and broken ice is much more likely to churn it up, breaking it and mixing it with the warmer waters underneath. Last year, we saw this process in action during the powerful Great Arctic Cyclone which emerged in August, churning up a large area of the Beaufort Sea, then drawing warm air in behind it, resulting in major sea ice losses.

At times when ice was thicker, moderate or powerful storms would not pose a threat for enhanced melt. But since 1979, the Arctic has suffered an 80% loss of sea ice volume.

This year, sea ice volume is currently at record low levels. Yet the ice pack is very spread out, boasting an area near 2002 values. This combination of wide coverage and low volume leaves the ice very, very thin and fragile. So now, even moderate cyclones like the one hovering near the North Pole can chew away at the ice.

If the CICE projections bear out, we’ll see the central ice pack greatly weakened in the wake of this storm just as solar radiance and warm air build into mid-June. At this point, such injuries to the ice make it more likely that rapid and catastrophic decline in coverage will begin to dramatically ramp up over the next few weeks.

As Neven over at the Arctic Ice Blog notes:

I feel the Arctic sea ice pack could soon go POP under the right conditions.

Let’s see:

  1. Thin, spread-out ice pack.
  2. Persistent storm chewing away the central ice.
  3. Large cracks and areas of open water riddling most of the ice pack.
  4. Large polynas forming behind the ice edge.
  5. Upwelling events eroding the bottom ice.
  6. Loss of Arctic expeditions in the region of the ‘thickest’ ice.
  7. June heat and constant, direct sunlight approaches.

Looks to me like a lot of the ‘right’ conditions are present.

In short, don’t let the high extent and area numbers fool you. The thin, spread out state of the ice leaves it more vulnerable, not less so. The sea ice is weaker and less resilient than it ever was. Only a cold summer and conditions favorable for ice retention are likely to prevent a record melt in either area, volume or extent. On the other hand, very bad conditions could result in near-total melt (under 1 million square kilometers end season area).

UPDATE:

Long-range weather models show the cyclone sweeping down toward the Mackenzie Delta, drifting back toward the Canadian Arctic Archipelago and finally returning to the Central Arctic by mid-June. Such a prolonged storm event would likely have a continuous weakening affect on the ice. Lower temperatures in the storm’s region would be more than countered by active wave energy and tapping of warmer, deeper waters which will have a tendency to erode the ice from beneath. Furthermore, warmer air is shown to follow in the wake of this storm, which may enhance melt through regions of already weakened ice.

In any case, this is a situation that bears close watching. A month-long, or more, storm harrying the Arctic could have quite an impact.

ECMWF weather model forecast for June 9th:

Cyclone june 9

(Image source: ECMWF)

Links:

CICE

DMI

Lance-Modis

The Arctic Ice Blog

Lake El’gygytgyn Study Shows Ice-Free Arctic At 400 Parts Per Million CO2

(Presentation on Lake El’gygytgyn Findings Prior to Report Publication in Science)

A new study produced by polar researchers and published in the journal Science confirms a much warmer and mostly ice-free Arctic during periods when Earth’s atmospheric CO2 reached levels equivalent to those seen today.

The study took sediment cores from Russia’s lake El’gygytgyn (pronounced El-Gee-Git-Kin) in order to determine climate conditions north of the Arctic Circle during a period around 3.6-2.2 million years ago. During this time, atmospheric CO2 levels were comparable to those witnessed today. So the study may well be a strong allegory for what we should expect if human CO2 levels remain near the dangerously high 400 PPM level.

Lake El’gygytgyn was formed by an impact crater around 3.6 million years ago. It is a deep lake, so deep it would cover all but the top tip of the Washington Monument. For the first 20,000 years after its formation, there was little evidence of life found in sediment cores from the lake bottom. However, after this period, pollen from local plants began to emerge. Some, like Hemlock and Douglas Fir, tend to crop up in much more southern areas indicating that ice-free conditions predominated this extreme northern region.

Julie Brigham-Grette, a professor in the department of geosciences at the University of Massachusetts Amherst and lead author of the new study, which was published May 9 notes:

“To get Douglas fir and hemlock that far north of the Arctic Circle — you have to have pretty warm summers and warm winters in order for those trees to establish there… There was probably no sea ice, and the whole Arctic was pretty well forested, so it was a very different world.”

The researchers lead by Julie Brigham-Grette note that for such plants to be established in this region, temperatures would have been about 8 degrees Celsius hotter than today. These temperatures are consistent with a mostly ice-free Arctic environment.

This research, along with a growing body of Paleoclimate science, indicates that climate is much more sensitive to CO2 increase than current climate models may suggest. Overall, Paleoclimate may well be a far better determiner of the end result of human fossil fuel emissions than models which seek to pin down extraordinarily complex processes and are still in the early stages of development. And if past climate indicators do prove to be the best guide, sustained CO2 levels above 400 PPM will push for a long term temperature increase of around 3-4 degrees Celsius globally and 8-10 degrees at the poles. More importantly, these high levels appear to wipe out most ice in the Arctic environment.

Responses to current Paleoclimate research among the scientific community indicate a potential shift to reliance more on this data and less on models for future predictions. Kate Moran, an ocean engineer, notes:

“This new paleoclimate record adds to the growing evidence that Earth’s sensitivity to these levels of greenhouse gases may be higher than previously thought. Understanding Earth’s sensitivity is one of the key parameters for predicting future conditions of the planet under global warming.”

Such arguments aren’t merely academic. Ice loss in the Arctic is proceeding at a pace far exceeding previous predictions. Sea ice has melted by 80% since the early 1980s and rapid glacial melt is occurring in all regions of the Arctic. So we have past Paleoclimate evidence being validated by current Arctic trends which seem to point toward a far more rapid loss of polar ice than previously estimated.

Even more concerning, perhaps, is the fact that the Arctic is responding to CO2 levels of about 2-3 decades ago when CO2 was closer to 350 ppm. Because of natural inertia, the current CO2 levels of 400 ppm won’t begin to have full impact on the Arctic for another 20 years or so. And, in light of recent findings, that is a rather chilling prospect.

Gifford Miller, a professor in the department of geological sciences at the University of Colorado Boulder, who conducts research in the Canadian Arctic seems to agree:

“The ice is melting at all elevations,” Miller said. “Even if there is no additional warming, it’s only a matter of time before the ice is all gone.”

In the context of current business as usual fossil fuel emissions, these are substantial statements. If no additional warming is necessary to melt all the Arctic ice long-term, then what happens if CO2 levels increase to 1,000 PPM and temperatures rise to 6 degrees Celsius above average by the end of this Century? One can expect that under such extreme conditions, Arctic changes will be extraordinarily rapid and chaotic.

Links:

Ice-free Arctic May be Near

When the Arctic was 8 C Colder

Sea Ice Volume Edging Back Into Record Low Territory

PIOMASapr2013

(Image source: PIOMAS)

Despite an ongoing and precipitous trend of sea ice loss, it still happens now and then. As cold air invades and re-freeze sets in, pace of new ice formation spikes and we get the potential for a bit of ‘recovery’ in sea ice area and extent by March-April following record summer losses. The trend for sea ice area and extent for these months is still down, however. According to NSIDC, extent is falling at a pace of about 2.5% per decade during March and April. This pace of loss is quite modest when compared to summer losses, even though the long-term trend is still down.

Sea ice volume, on the other hand, is an entirely different story. The measure of total ice area + ice thickness as determined by PIOMAS has crept steadily and rapidly downward during both winter and summer months. Though the total loss below the 1979-2012 average is slightly greater for summer (approx. 9,000 cubic kilometers) it does not greatly exceed the loss seen during winter months (about 7,000 cubic kilometers) since 1979. (Percent losses for summer exceed 25% per decade while percent losses for winter are about 13% per decade. So the pace of summer volume loss in this measure is still much greater.)

There is, however, one small wrinkle in this observation. Winter sea ice volume measurements have tended to cluster in a given range before taking large steps down during certain years. Summer, on the other hand, has shown more steady and consistent melt with large step years spaced out by many years of more moderate melt.

So it was little surprise when sea ice volume tied and slightly exceeded March 2011 and 2012 measurements for brief periods during the winter of 2013, edging above the record low value by about 70 cubic kilometers on certain days.

Now, PIOMAS shows pace of volume melt rapidly increasing through mid April. And this new melt has brought Arctic sea ice volume back into record low territory, edging about 80 cubic kilometers below the record set in 2011 for that time.

Sea ice volume is the critical measure now that validation from satellite instruments has clarified the accuracy of PIOMAS modeling. Area and extent only measure the surface as visible from above. But the total proportion of remaining ice is captured by current volume measurements. And what PIOMAS is showing, at this point, is that sea ice volume in the Arctic is currently lower than it has ever been in modern reckoning.

Links:

PIOMAS

Pace of Sea Ice Melt Increasing, Numerous Regions Showing Rapid Decline

Jaxa sea ice

Last week saw a quickening pace of sea ice melt, with key regions displaying rapid loss of ice.

Most rapid melt occurred in the Barents Sea which saw major ice losses both to the north and south of Svalbard, north and south of Franz Joseph Land, with a large polyna opening to the north of the island and more gradual melt to the south and west of Novaya Zemlya.

Other regions showing rapid melt included the Bering Sea and the Sea of Okhotsk. Most sea ice in the Okhotsk region has been driven shoreward with Bering ice rapidly melting in the southeast and the entire ice pack there showing thinning and opening polynas.

The Fram Straight and Baffin Bay showed more moderate rates of ice recession.

Sea_Ice_Extent Apr 26

Overall, sea ice extent, according to the Japanese Space Agency (JAXA) is currently at 12.86 million square kilometers. This measure is tracking just below values for 2011 for this time of year. Sea ice area also showed more rapid melt this week with values falling by 400,000 square kilometers over the past seven days to reach 12.56 million square kilometers yesterday. Average rates of daily loss remain between 50,000 and 70,000 square kilometers for area with the pace picking up to around 90,000 square kilometers per day at week’s end.

The pace of loss for both area and extent remain above average for this time of year, matching the extreme rate of loss that began to emerge during 2012 at this time of year. Furthermore, all the latest measures show sea ice volume remaining at or near record low levels while multi-year ice coverage is at lowest levels ever.

arctic.seaice.color.000

Loss of Arctic snow cover and corresponding river melt for this time of year also accelerated. Areas near Hudson Bay, in northeastern Europe, and central Siberia showed the most rapid melt. As snow melt accelerates, rivers fill with warmer melt waters that then flush into estuaries and the ocean. This snow-melt flushing warmer water into the ocean usually pushes melt faster during May and June. This year, the process appears to be happening at least two to three weeks ahead of schedule.

Arctictemps27apr2013

Above-freezing air temperatures continue to advance northward. Air warm enough to facilitate large-scale melt has invaded most of Siberia and Northern Europe. This week also saw above freezing air temps regularly pushing north toward Svalbard and into the Barents sea. The Sea of Okhotsk has seen above freezing temps for much of the week, with the Bering Sea also experiencing above-freezing air temperatures. In Canada, the melt line has regularly advanced into Northern Quebec, covering southern portions of Hudson Bay. The southern tip of Greenland also shows consistently above-freezing temperatures. Colder air, however, remains entrenched over north-central Greenland and over the northern portion of the Canadian Arctic Archipelago.

meanT_2013

Average air temperatures in the high Arctic remain well above normal for this time of year with today’s values showing temps between 6 and 7 degrees Celsius above mean for most areas.

In the context of this report, it is worth noting that sea ice melts at around -1.9 degrees Celsius. So near freezing or above freezing air temperatures are usually enough to promote melt. Ocean temperatures beneath the ice hover at or above the freezing mark as well. So the ice is under stress not only from the surrounding air, but also from beneath as warm water upwelling events have become more frequent. Sunlight is also now a constant in the Arctic. So any open water areas, showing dark ocean, will tend to rapidly absorb heat. In addition, an unprecedented number of leads have shot through the ice this winter and spring. These crack are both darker and warmer than the surrounding ice. So weaknesses are likely to begin to appear as warming starts its more rapid cascade over the coming weeks.

color_sst_NPS_ophi0

As noted above, warmer than freezing sea surface temperatures compose one of the main forces promoting ice melt. The above graph, provided by NOAA, shows expanding regions of above freezing (sea water) surface water in Hudson Bay, The Canadian Arctic Archipelago, in a region of the Arctic Ocean north of Alaska and Canada, the Bering Sea, the Sea of Okhotsk, in multiple areas over the East Siberian Arctic Shelf, and in a growing region of the Barents Sea.

Arctic_r03c05.2013117.terra.1km

The combined impact of constant sunlight, above-freezing water and rising air temperatures is starkly visible in this most recent Lance-Modis satellite shot of a region of the Barents and Kara Seas. This region shows rapidly fracturing ice with numerous expanding polynas as regions of open water creep northward. In large regions, newly open water shows no sign of surface refreeze and instead has rapidly invaded the weaker ice. Such conditions are now common in many regions near the ice edge.

Overall, the Arctic has now entered a phase which shows increasing risk of rapid to very rapid melt. High temperatures, warming and above average ocean temperatures, continued invasions of warm air, rapid snow melt in Siberia and expanding regions of dark, sunlight absorbing water all will likely conspire to speed melt in the coming weeks. So the forecast is for moderate to rapid (and possibly near-record) melt over the next 7-14 days. One caveat is that the Beaufort Sea has remained cold and that Arctic Oscillation has remained positive. The result is that risks for a rapid Beaufort melt appear to be lower at this time. However, ongoing moderate new re-cracking north of the Canadian Arctic Archipelago may render this, somewhat comforting, observation premature.

Overall, sea ice melt appears to be on pace to hit or rival most recent record lows. Our forecast remains that there is a high (60%) likelihood that either sea ice area, extent, or volume will reach new record lows in 2013. There is a moderate risk that all measures will show a new record low by the end of this year (35%). And there remains a low but significant risk that the Arctic will be essentially ice-free by the end of this summer (20%).  Chances for total ice melt (an event that likely hasn’t occurred in the past 400,000 years), as noted in previous posts, remains low at 10%.

(Note: we define ‘essentially ice free’ as an Arctic showing less than 1 million square kilometers of surface ice area and/or extent by summer’s end. This ‘essentially ice free’ state is defined as a surface area of less than half that of Greenland.)

As the melt season progresses, we will continue to refine predictions and global risk analysis. It is worth noting that no year since sea ice record keeping began has ever shown risk of total or near ice free conditions. So the 2013 melt season is already a historic one in that respect. Finally, as noted in previous posts, risk for total melt or near ice free conditions continue to rise over the coming years.

Links:

The Japanese Space Agency

Cryosphere Today

Uni-Koeln

DMI Centre for Ocean and Ice

NASA Lance-Modis

Uni Bremen, JAXA Show Sea Ice Extent in Rapid Early Season Decline

Uni Bremen Sea Ice Cliff

(Image source: Uni Bremen)

The most recent updates from the Japanese Space Agency (JAXA) and Uni Bremen show Arctic sea ice extent in very rapid early season decline. The above graph, produced by Uni Bremen, shows a stunning loss of sea ice extent over the past week of more than 1 million square kilometers. Such extent losses are almost unheard of for this time of year, with retraction, at least according to Uni Bremen, even out-pacing what is usual for July and August.

Uni Bremen is not the only sea ice extent monitor and not all the others show such a rapid decline. Uni Bremen uses less smoothing, so we will expect to see whether these numbers bear out in the other measures over the coming days. Ominously, JAXA is also showing a rapid extent decline:

JAXAextent17April2013

(Image source: JAXA)

Though neither as extensive nor as sudden as Uni-Bremen losses, the JAXA graph does show a rapid decline of about 500,000 square kilometers over the past week. NSIDC and DMI, on the other hand, show declines to be much more gradual. The NSIDC area measurement also is currently showing a much more gradual decline.

As noted above, the discrepancy between these measures should wash out over the next week. But early indications from JAXA and Uni-Bremen are some cause for concern.

Conditions in Context

Arctic conditions in context show warmer than average air temperatures remaining over much of the region. These departures from normal high and low temperatures are not as great as they were a week ago. However, these warmer than normal air temperatures are also now riding on top of a seasonal increase and so more rapidly push the Arctic toward melting.

Warmer than average water temperatures also continue to pervade over most of the Arctic Ocean. Recent reports have confirmed sporadic warm water upwelling throughout the Arctic. These events contribute to bottom melt  and cracking of sea ice and are just one more mechanism pushing the Arctic sea ice into decline. Such warm water upwelling is likely linked to a rapid increase in ocean heat content. A portion of this newly sequestered heat energy appears to already have done quite a bit of work in reducing Arctic sea ice extent, area and volume. One such upwelling event occurred off Barrow Alaska in March of 2013. The event combined with off-shore winds to result in ice free waters for a short time off Barrow, one of the consistently coldest locations in the Northern hemisphere, in winter time. Such events have been known to occur. But the up-welling and wind driven melt this March was one of the largest such winter-time events yet witnessed and it coincided with an immense sea ice cracking event.

Arctic Weather 17apr2013

(Image source: Uni-Koeln)

Overall, we see warm air temperatures over Eastern Europe and Russia rapidly expanding northward with above freezing temperatures crossing the Arctic Circle in some areas. Even Siberia is seeing rapidly warming temperatures. Cooler air remains settled in over Greenland and the Canadian Arctic Archipelago (CAA). These conditions are somewhat the reverse of those seen earlier in the month when Greenland and Baffin Bay showed warmer temperatures while Europe and Russia shivered.

As the Arctic continues to warm, we are likely to see sea ice melt continue at a slow to moderate pace. That said, an increasing number of indicators show the potential (low to moderate) for a major pick-up in early season melt rates come late April/early May. Should these events emerge, the upshot would be the possible start to a summer of massive Arctic melt. A melt that would be the pre-cursor or possibly even the start of a new period of ice-free or near ice-free summers. It is still too soon to make this call. That said, it is possible we are seeing some foreshadowing in the Uni-Bremen and JAXA measures showing very rapid extent losses over the past week.

As a final note, it important to re-iterate that the Arctic sea ice remains extraordinarily thin, fractured and fragile for this time of year with continued rumblings that melt may begin to proceed rapidly and well ahead of schedule.

UPDATE:

Uni-Bremen has just posted a revised estimate of sea ice extent. This revision shows melt occurring at a somewhat more gradual pace. You can view the revised data here. JAXA estimates, however, remain the same as previously posted.

NOAA: Nearly Ice Free Arctic Summers Likely To Come Sooner, Current Sea Ice Melt Models Too Slow, But Still Useful

In a recent press release, NOAA has revised its predictions for an ice-free or nearly ice free Arctic Ocean.

The statement publicizes work by two scientists, James Overland and Muyin Wang who have now incorporated three methods of determining when an ice free or nearly ice free Arctic is most likely to manifest. Their work recently published in Geophysical Research Letters and is available there.

Overland notes:

“Rapid Arctic sea ice loss is probably the most visible indicator of global climate change; it leads to shifts in ecosystems and economic access, and potentially impacts weather throughout the northern hemisphere. Increased physical understanding of rapid Arctic climate shifts and improved models are needed that give a more detailed picture and timing of what to expect so we can better prepare and adapt to such changes. Early loss of Arctic sea ice gives immediacy to the issue of climate change.”

Wang adds:

“There is no one perfect way to predict summer sea ice loss in the Arctic. So we looked at three approaches that result in widely different dates, but all three suggest nearly sea ice-free summers in the Arctic before the middle of this century.”

The three approaches Wang and Overland incorporated:

1. A trends analysis that predicts nearly ice free conditions by around 2020. This analysis takes into account past average rates of sea ice loss and extrapolates it forward in time. The analysis Wang and Overland put together establish a nearly ice free state by 2020.

2. A stochastic approach that incorporates a higher natural variability with large, somewhat random, melt events resulting in a near ice-free state by or before 2030.

3. A model approach which still shows nearly ice free summers occurring during a period between 2040 to 2080.

Wang and Overland note that the model predictions are likely to be much slower than actual melt. That said, they defended the models saying it was necessary to continue their development in order to better understand the Arctic climate.

Overall, this represents a rapid shift on the part of NOAA. Past official estimates were for near ice free conditions being most likely after the first half of the 21rst century. But with rapid melt trends pushing for a much sooner melt date, NOAA has adjusted its forecast. Given this most recent paper, Wang and Overland seem to indicate a most likely near ice free state in a time period of 2020-2050.

NOAA’s Predictions in Context

It is my opinion that the range NOAA gives of between 2020 to 2050, with caveats that model predictions are likely to be too slow, is still a bit too conservative in that it fails to give warning to the rising risk of an almost immediate melt. Just following current melt trends brings us to a completely ice-free Arctic by 2017. Any single melt year like 2007 or 2010 (volume) brings us to an ice free or nearly ice free state in one year.

Perhaps NOAA could add another set of circumstances to its analysis — the exponential melt trend analysis. Such a trend would incorporate the risk of a near immediate melt, warn the public and governments of the potential for such an event and give NOAA a more realistic near ice free range of 2015-2050.

In doing this, NOAA would acknowledge the potential for an ice-free or nearly ice-free state within the current decade. This acknowledgement is important from the standpoint of emergency preparedness. An ice free Arctic and the likely climate mayhem it would produce is not something we generally want to remain unaware of.

Risk assessment forecasts provided at this blog and incorporating sea ice volume data from PIOMAS show a 10% chance of an ice free or nearly ice free state this year, with a high risk (60% chance) of an ice free state by 2017. Some polar experts like Peter Wadhams believe that the Arctic will reach an ice-free state as soon as 2015-2016. Wadhams has spent thousands of hours researching the ice aboard navy submarines. So if there’s someone who knows sea ice, it’s Wadhams.

While negative feedbacks that slow the loss of sea ice may emerge, any prediction for a near ice free state after 2020 hangs its hopes on those, yet to emerge, melt inhibitors. More likely, the reduced resilience of the ice will compound with a warming climate to push melt to occur with a bang and not a long, drawn-out whimper. Further, the fact that the ocean upon which the ice rests is collecting a greater volume of human produced warming is likely to enhance bottom melt regardless of atmospheric temperatures, even in winter time. We can see this in the catastrophic volume losses observed even during the coldest months with current peak volumes comparable to those of the warmer months during the 1980s.

If current volume trends bear out, we see ice free winter states by 2040. Something neither the models, nor NOAA have on their public radar.

What is happening in the Arctic currently constitutes the beginning of a global climate and weather emergency. The UK Met recently called an emergency meeting due to a rapid shifting in the UK climate as a result of catastrophic sea ice melt. Such emergency sessions are likely to become more common as time goes forward. NOAA’s movement on this matter does represent an increased alertness to the scope of the problem and should be applauded. The work of their scientists and modelers has enabled a greater understanding of the Arctic than ever before. However, for scientists to remain on the cutting edge, they will have to adjust to events far more rapidly than in the past. They will also need to begin to acknowledge the potential for dangerous outlier events.

The current NOAA statement strikes a balance between the traditional conservatism of science and the need to acknowledge an Arctic undergoing catastrophic change far more rapidly than anyone expected. Thus, it represents progress. That said, if current trends bear out, these still somewhat conservative predictions of near ice free conditions via NOAA may soon be moot.

The Collapse of Arctic Sea Ice: Will Beaufort Break-up and Melt Proceed a Month or More Ahead of Schedule?

The scientists are worried. The Arctic is responding to human-caused climate change much faster than expected. As little as a year ago, scientists weren’t predicting an ice free summer Arctic Ocean until around 2060 to 2080. Then the 2012 melt season erased all hope that melt would proceed at such a gradual pace.

Now, most scientists predict that summers will see an ice-free Arctic Ocean by 2030. Unfortunately even this, much earlier, date may be too conservative for the Arctic sea ice, which appears to currently be shattering under a death blow of global proportion. And it is, for this reason, why we should seriously listen to one scientist who has spent much of his career listening to the sea ice.

Peter Wadhams, a polar researcher for most of his life, spent more than 40,000 hours on naval submarines, taking an intimate account of sea ice health and thickness. And Dr. Wadhams doesn’t think the summer sea ice has much longer to live. He predicts an ice-free or near ice free state for the Arctic Ocean come 2015 or 2016. In a recent interview to The Guardian, Wadhams stated:

This collapse I predicted would occur in 2015-16 at which time the summer Arctic (August to September) would become ice-free. The final collapse towards that state is now happening and will probably be complete by those dates.

Wadhams’ prediction comes very close to fitting the current trend of sea ice volume losses which will result, if trends continue, in an ice free Arctic come summer by 2017. However, as noted in a previous analysis here, any single melt year comparable to 2007 or 2011 would be enough to take down all or most of the remaining sea ice in just one year.

So the critical question is this: is such an event occurring now? Are we experiencing the final collapse that Wadhams mentions? If so, how would we know? Given that we have no precedent for what is happening to the sea ice, it is far more difficult to predict what may happen than, say, in a weather forecast. Regardless, there may well be a number of clues that are showing us a very big melt season and, with it, the last days of Arctic sea ice is well on the way.

Enter the Beaufort sea ice. The Beaufort sea contains ice that protects the rear of the remaining thick ice. Beaufort ice acts as both wall and insulator to the dwindling last bastion of multi-year ice now huddled protectively next to Greenland and the Canadian Arctic Archipelago. Should that protection disappear too rapidly or too early, much of that remaining ice may not be able to make it through the Arctic summer.

Unfortunately, Beaufort sea ice underwent a major cracking event from February to March. Such events usually don’t occur until April or May. But this year’s cracking event came 40-50 days sooner. It also came with a vengeance. The cracks, usually contained within the Beaufort Sea, spread to cover much of the Arctic, invading even the remaining thick, multi-year ice. Not only did this cracking event rupture the thick ice, it also appears to have taken it off its anchor point.

This combined impact is likely to leave the multi-year ice both more fragmented and mobile come summer. And it could spell disaster for the remaining sea ice.

How will we know if this sea ice doomsday scenario is proceeding? One hint that it is occurring will be seeing something like the below image progression appearing in the vicinity of Banks Island in early May:

ModisFinalBigIndexSmallBB2_zps8f64a49d

(Image source: Ice Blog/A-Team)

What you are seeing in the above image is a break up of sea ice that occurred from March 30th to June 15th of 2012. This event bears striking similarities to this year’s February break-up. It contains the same network of ring fractures and it resulted in radically reduced resilience of Beaufort sea ice come mid-summer. The difference is that last year’s break-up began about 45 days later and was much smaller. It did not include the thick sea ice, nor did it pull that ice from its anchor points. This year’s break-up did both.

For comparison to this image sequence here is a picture of the sea ice in the same region today:

beaufort05Apr13_zps1df4b93c

(Image source: MODIS)

The state of sea ice in the same region now roughly corresponds to the state of sea ice in the same region during early May of last year. Arctic Ice Blog commenter A-Team notes:

Comparing 2012 visible imagery to 2013 infrared is somewhat problematic but the best match to today’s date 05 Apr 13 is approximately 10 May 12, or 35 days later. The southern coastline in the vicinity of Banks Island provides the best diagnostic region.

Recall 2012 was a record melt year with a very similar arc fracturing pattern developing in the Beaufort. However this developed much later in the spring and did not extend past the Prince Patrick Island leverage point.

In summary, the rapid acceleration of Beaufort Gyre rotation in early June 2012 and the breakup of icepack into floes can be expected in early May for 2013. This will contribute to a vastly more extensive melt-out expected in late summer 2013.

So what is setting up to happen next, should this worst case estimate proceed, is that the Beaufort Gyre will rapidly accelerate come early May, resulting in a disintegration of sea ice similar to what is seen in the above picture, but about 30-40 days ahead of schedule. The Gyre is a surface current that circles the Beaufort Sea. Ice on the water tends to retard the flow of this current. But as the ice becomes less solid, the Gyre speeds up, aiding in the breaking and mixing of sea ice with warmer waters. This process, as seen in the image sequences above, can lead to a rapid collapse and melt-out of sea ice.

If such an event does occur at such an early date, it will be one more indication that summer 2013 melt is proceeding at a much faster and more dangerous pace than even 2012. The early break-up was a strong indication that melt may be much worse for this year. If an early melt and speed up of the Beaufort Gyre occurs in this region, it will be one more sign that the summer of 2013 could be one in which further dramatic and dangerous melt occurs. One which may spell out the last days of Arctic sea ice.

Links:

The Arctic Ice Blog

Total Meltdown Warning

How Global Warming Enhanced Glacial Melt to Expand Sea Ice in Antarctica

antarctica

Overall, worldwide sea ice totals have been declining over the past few decades. This trend has been led by a massive summer collapse of sea ice in the Arctic. But, on the other side of the world, in Antarctica, sea ice area and extent have been slowly expanding. This seeming contradiction recently spurred researchers to take a closer look at Antarctica to determine why sea ice would be expanding even though worldwide atmospheric and ocean temperatures are on the rise.

What they found was an amazing and complex combination of forces driving a moderate sea ice expansion in the southern hemisphere. Warmer waters coming into contact with submerged glaciers slowly melts the ice. In addition, a warming Antarctic continent disgorges large volumes of water each year. This fresh melt water, flushing into the ocean at a rate of 250 gigatons each year, then expands, covering the ocean surface in a thin layer surrounding Antarctica. Not only does this fresher water freeze at higher temperatures, it keeps warmer waters from rising up to melt the sea ice from below. The result is that sea ice is both insulated and made of fresher water. So until atmospheric and ocean temperatures rise enough to overwhelm this dynamic, Antarctic sea ice will remain protected by insulating processes coming from melting glaciers.

Warmer water trapped in the ocean depths surrounding Antarctica has also played a role in heating the world’s deep oceans. This heating was recently detected in a new study conducted by Kevin Trenberth and colleagues. The study found that a significant portion of the last decade’s heating had been sequestered in the deep ocean. Now it’s apparent that glacial melt in Antarctica may have played a role.

The Arctic sea ice, thus far, hasn’t benefited from a similar insulating process. The result was an 80 percent sea ice volume loss since 1979 and a high risk that sea ice will completely melt one summer between now and 2020. It’s possible that Greenland melt may continue to increase, freshening the Arctic’s waters, and providing a similar benefit at the cost of enhanced sea level rise and more extreme weather. But ocean currents, geography, and salinity dynamics for the Arctic are different from that of the Antarctic. So it is uncertain if melt will play as large a role in insulating northern hemisphere sea ice as it has in the southern hemisphere.

It is worth noting that rapid glacial melt, though it drives more extreme weather events even as it more rapidly increases sea level, tends to put a powerful damper on global temperature increases once glacial melt reaches the 1 meter mark. The heat energy goes more into melting the ice and less into warming the atmosphere and oceans. The negative feedback of fresher ocean waters in the polar regions as well as iceburgs floating in rapid glacial melt zones also has a net cooling effect. The result is that a degree or more of global temperature increases may be ‘held in check’ as the ice melts. Rapid ice melt decades may result in brief periods of relative cooling (where temperature increases back off from 1.5 or 2 degrees above average to around .9 to 1.3 degrees above average).

It’s a balancing effect and trade-off where you end up with more changes to the Earth’s environment and less overall heating in the short-term. This delayed heating effect of ice melt should not be seen as a good sign, however. As mentioned above, it comes at the severe cost of increased weather extremes and more rapid ocean level increases. In the end, once the messy transition decades are passed, a more liquid ocean results in more water vapor in the atmosphere, warmer Arctic and Antarctic environments that pump more greenhouse gasses into the atmosphere, receding glaciers and snow cover reducing the Earth’s reflectivity and adding further warming, and a warmer deep ocean resulting in more ocean methane release.

To get an idea how Greenland and Antarctic melt might dramatically impact world weather while putting a short-term dampening on global warming over the coming decades, take a look at this paper by James Hansen:

Update of Greenland Ice Sheet Mass Loss: Exponential?

It is worth noting that the scenarios examined in the paper come as a result of a relatively moderate increase in human greenhouse gas emissions: the A1B scenario. However, current emissions have increased more along the A1FI scenario which would likely result in even more climate volatility than the Hansen paper suggests.

The thing to take away from this new study is that both the Arctic sea ice collapse and the slower expansion of Antarctic sea ice are caused by the same forcing — human caused global warming — and that the glacial melt now resulting in localized cooling is also driving enhanced sea level rise and more extreme weather.

Please find more information on these new, ground-breaking studies here:

Global Warming Expands Antarctic Sea Ice

Oceans Continue to Warm, Especially in the Deeps

Late Winter Arctic Cracking Event, Rapid Ice Motion Resulted in Loss of Thick Ice

AM2SI20130328RGB

(Image source: JAXA)

A major early season Arctic sea ice cracking event has mostly run its course. This unprecedented and much sooner than usual ice break-up left scars all over the Arctic. Scars that are likely to leave the ice in a much weaker condition as the current melt season ramps up. The most obvious are visible as cracks and leads through even the thickest ice. But equally concerning is a very rapid transport of thick ice out of the Fram Straight over the past few weeks.

Export of ice through Fram is usual, regardless of season. What is unusual is that this particular event occurred with such high velocity that it rapidly depleted a large region of the Arctic’s remaining thick ice. The acceleration of sea ice motion during the recent cracking event pushed enormous sections of ice to the north of Greenland, ice that had previously been part of the swiftly dwindling multi-year ice pack, out into the North Atlantic where it is destined to collide with warm ocean currents and melt out. Looking at an animation of sea ice since mid-February, it looks as if the thick ice is being squeezed out of the Arctic like toothpaste is squeezed out of its tube.

Multi-year ice (MYI) has been in rapid decline ever since the year 2000 and is now at lowest levels in any historic record. This ice is also the Arctic’s thickest, its freshest and its most resilient to melting. MYI decline, cracking and rapid export through the Fram Straight is leaving it more and more weakened for the upcoming melt season. This depleted state, combined with the fact that most of the remaining Arctic is now covered in first and second year ice means that the sea ice will be far more vulnerable to weather, wind, waves, sunlight and heat come summer.

It is the year after year decay of the thick, multi-year ice that is just one factor making ice ever more vulnerable. Ever increasing ocean heat content, decreasing spring snow cover, loss of Arctic reflectivity or albedo, increasing expanses of dark, sunlight and heat absorbing water, increasing Arctic greenhouse gas feedbacks, changes in the water column due to methane hydrate destabilization, and ever-increasing human greenhouse gas emissions are all factors pushing the Arctic toward more rapid transition.

Links:

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e

Arctic Calmer For Now, Slow Spring Melt Continues

The drama appears to have mostly subsided for now. An unprecedented cracking event that began in February and expanded through mid-March seems to have mostly paused. Brief openings revealing open water have mostly frozen over with thinner ice.

This is not to say that the Arctic is entirely quiet. Thick ice has continued to lift away from the CAA and Greenland, resulting in a spreading and thinning of ice in these regions. Ice shows rapid movement out the Fram Straight. Tantalizing hints of new cracks emerge. And a slow melt proceeds.

seaice.recent.arcticmar27

(Image Source: Cryosphere Today)

Cryosphere Today shows sea ice area dropping slowly to about 380,000 square kilometers below sea ice maximum. The current measure, 13.399 million square kilometers is the seventh lowest on record for this date and somewhat lower than the 2012 measure for today.

The smoothed NSIDC graph shows decline continuing in sea ice extent, with measurements of around 14.9 million square kilometers. This measure is now outside the -2 standard deviation range and shows continued slow decline. Sea ice extent has been hovering around 5th lowest on record for the past few days.

Cracks Mostly Stable, Though Fissures Appear More Pronounced Near North Pole

Major crack expansion seen in February and early March has abated over the past week. However, some features of interest do appear on recent satellite shots. A series of fissures can now be seen traversing the thick ice in a crescent moon pattern west of the North Pole and running up from Greenland and the CAA. These appear somewhat more pronounced than yesterday, though enhanced clarity may be from a better satellite shot. In any case, these fissures as well as the Beaufort cracks will bear watching over the coming days and weeks as spring season melt intensifies.

hrpt_dfo_ir_100mar27

(Image Source: Canadian Weather Office)

General Climate Conditions

Overall temperatures for the Arctic remain above average with warmer than normal temperatures concentrating around Greenland, Baffin Bay, and the Canadian Arctic Archipelago (CAA). A pool of above average temperatures also remains north of Siberia. Weather maps show high pressure continuing to dominate the central Arctic with a series of weak to moderate low pressure systems skirting the area of this high in the Bering, Northern Canada, and South of Svalbard. A strong low (970mb~) approaches Greenland, Iceland and England from the North Atlantic.

Though the central Arctic high still dominates, negative Arctic Oscillation values have fallen to around -3.8 from a peak of about -5.5 more than a week ago. Negative AO values are forecast to shift closer to zero come early April.

Overall, higher than average temps, what appears to be still fragile ice, still rapid ice mobility, and weather systems whittling away at the ice edge would still seem to favor slow ice melt over the next week. That said, we may experience a small bump in sea ice values as somewhat colder air briefly over-rides the current melting trend. Generally, though, seasonal forcing would tend to combine with the above factors to push for continued gradual melt.

Links:

http://nsidc.org/arcticseaicenews/

http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index.html

http://arctic.atmos.uiuc.edu/cryosphere/

http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/arcisoTTPPWW.gif

NSIDC Calls Sea Ice Maximum, Melt Continues, Thickest Ice Shows Rapid Motion

Quite a lot going on in the Arctic Today…

First off, NSIDC has officially called sea ice maximum (The tip off came from Neven. His sea ice blog is fantastic. Read it, comment on it, and stay informed.) From NSIDC:

On March 15, 2013, Arctic sea ice extent appears to have reached its annual maximum extent, marking the beginning of the sea ice melt season. This year’s maximum extent was the sixth lowest in the satellite record. NSIDC will release a detailed analysis of the 2012 to 2013 winter sea ice conditions in early April.

So here we are, 9 days into the melt season. Par for the course, we have sea ice melt continuing in most key measures today. Here is a visual of the sea ice extent data from NSIDC:

N_stddev_timeseriesmar25

As you can see, NSIDC extent measures take a rapid dive right to the edge of the -2 standard deviation line. This is a pretty steep decline rate so early in the year and we’d expect it to pause now and then. With current major ice sheet fracturing and storms churning up the ice edges in the Barents and Sea of Okhotsk, these measures will bear close watching.

Fracturing and Rapid Ice Motion

Speaking of fracturing, it is certainly worth taking another look at the very splintered mass of thick ice north of Greenland, the CAA, and Alaska. The most recent satellite shot from the Canadian Weather Office is almost tragic in its poetry. A view down through the clouds provides some stark contrast for all those cracks and leads that have opened up over the past month:

hrpt_dfo_ir_100mar25

This image provides a static shot of an Arctic in rapid transition. The cracks you can clearly see, however, provide a hint to how volatile even the early spring Arctic has become. What the US Navy CICE map shows (analysis provided by A4R) is that a broad section of thick, multi-year ice is now on the move. It is possible that this new motion will further crack an already fractured system, creating even more leads and melt avenues for spring and summer warming. The CICE motion forecast is below. Again, something that bears close watching:

arcticicespddrfnowcastMar25

Lots of features in this Navy ice motion model worth discussing. The first is the motion of thick ice moving away from Greenland and the Canadian Arctic Archipelago (CAA). This is the motion I mentioned above which may result in further fracturing of the thick ice. Other features show rapid movement of ice out the Fram Straight. Fram is, essentially, the graveyard of sea ice, so rapid transport out the Fram is not good for overall ice health. Moving further south, we can see a pretty rapid east-to-west flow in Hudson bay. At this time of year, Hudson is still ice clogged. But we might end up with thinner ice on the east end as a result.

Next come the low pressure systems. The first, rather weak, system appears just north of western Canada and eastern Alaska. This system seems to be combining with a high pressure near Greenland to lift thick ice away from Greenland and the CAA. The second appears in the Bering Sea and appears to be doing a decent job mixing the thin ice there. Finally, a strong low in the Sea of Okhotsk is turning thin ice in that region into a big blender.

Slight Cooling Continues, Temps Still a Bit Above Average

A gradual cooling trend that began a few days ago appears to have bottomed out today. That said, temps still remain mostly above average throughout the Arctic. Taking a look at the global temperature composite provided by NOAA shows much of the warmth concentrated over Greenland, Baffin Bay, and the CAA with other pools of warm air concentrating over the East Siberian, Laptev and Barents Seas.

globaltempsmar25

Overall, conditions still appear to favor slow, overall melting with erosion of sea ice in the Bering and Okhotsk Seas somewhat offset by ice attempting to expand east of Svalbard. Rapid ice transport out the Fram Straight and thick ice lifting away from Greenland and the CAA may create further weaknesses in the ice that could have greater impacts later in the season. We should have a better view of any possible impacts come tomorrow.

Arctic Melt Continues, CAA Shows Cracks, Negative AO, Warming Subside a Bit

arcticice_nsidcmar24

(Image Source: NSIDC, Pogoda i Klimat)

Arctic sea ice melt continued over the past two days with both NSIDC and Cryosphere Today showing continued lower area and extent values. The Japanese Space Agency sea ice monitor (JAXA), showed slightly higher extent values but didn’t buck the overall melt trend. Overall, sea ice area measures are about 370,000 square kilometers below maximum. So a melt trend is pretty well established as the 500,000 square kilometer threshold approaches.

Historic Cracking Event

A very large cracking event that is unprecedented for its size so early in the season seemed to pause this weekend. That said, cracks did continue to appear in somewhat unlikely places. Poster Espen over at the Arctic Ice Blog pointed out a series of cracks from a NASA shot of Lancaster Sound. Located in the Canadian Arctic Archipelago, Lancaster Sound is a part of the network of seaways that make up the Northwest Passage. Early breakage in this region may, but does not conclusively, point toward an early opening of the Northwest Passage for this year. Will have to keep an eye on events as new conditions emerge.

NASAshotLancasterSound

(Image source: NASA Earth Data)

For an excellent overview of this major ongoing cracking event, take a look at this article written by Neven and re-posted both in Skeptical Science and Climate Progress.

Negative AO, Warming Subside

The extraordinarily powerful high pressure system contributing to a strong negative Arctic Oscillation (AO) has diffused into a larger ridge stretching from northern Russia to Baffin Bay. Pressures within the ridge have been slowly falling. As a result, negative AO phase has weakened somewhat, falling to a value of negative 4.5.

The Arctic has also cooled a little from earlier high temperatures. That said, temperatures remain above average for this time of year.

ArcticmeantempsMar24

(Image source: DMI)

All that said, the overall blocking pattern transporting heat into the Arctic over Greenland and Eastern Siberia appears to remain intact. Further, the polar jet stream is very wavy, with lots of warm air intrusions from the south and cold air influxes from the north. Looking at weather models covering the next 10 days, this waviness in the jet stream appears to intensify as spring continues to emerge. This pattern is likely to drive warm air repeatedly into the Arctic’s heart while forcing colder air out and onto the continents.

Notable Weather Events

A low pressure system forming just east of Kamchatka disrupted thin sea ice in the region. This energetic low swirled the ice to such an extent that its effect was visible on the Navy sea ice thickness composite below. This mixing led to some loss of sea ice in the region. According to ECMWF model forecasts, the low is expected to strengthen and move toward the Barents Sea over the next couple of days. So areas of Barents sea ice may also see disruption as the low deepens and churn through the region. Later, another low is set to emerge again over The Sea of Okhotsk.

Navyseaicemar24

Overall, melt appears to be eroding ice in Baffin Bay (likely due to warmer than average conditions), in the region of The Sea of Okhotsk (storminess appears to be playing a role here), and in the fast ice just east of Greenland and on the south side of Svalbard. Spreading areas of thinner ice continue to emerge or remain north of Barrow Alaska and Northern Canada. A large fissure between the Canadian Arctic Archipelago and the thick ice that usually anchors there this time time of year continues to stress and disrupt the multi-year ice.

Weather conditions, though slightly less favorable than a couple of days ago, would seem to still contribute melt on the back of an over-all slow warming, erosion of the ice edge, record thin ice values, and a slow increase in sunlight typical for this time of year.

I’ll leave you with this image from the Canadian Weather Office. As you can see, some of the leads from this past month’s cracking event appear to have snowed over a bit. A view that appears serene and calm, for now.

Arctic ice mar 24

Advertisements
%d bloggers like this: