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Heatwave Sends Temperatures in Alaska to 94 Degrees. Large Pulse of Warmth Envelopes Beaufort, Chukchi, and East Siberian Seas.

Yesterday, temperatures in Prince William Sound hit upwards of 93 degrees. Communities there, including Valdez and Cordova, both set new record highs. Talkeetna hit 94 degrees, also an all-time record high for the date. Meanwhile, Seward hit a new record of 88 degrees Fahrenheit. Temperatures in the interior rose to between the mid 80s and lower 90s.

This pulse of heat was driven by a persistent bulge in the Jet Stream over the Pacific Ocean, the Western United States, and the Pacific Northwest that has been present since mid winter. The bulge has resulted in warmer than normal temperatures and drier conditions for much of the Western US while keeping temperatures warm for western Canada and Alaska. It is a blocking pattern implicated in the ongoing drought conditions in places from Colorado to Nevada and California. A pattern which sees 44% of the US still locked in drought.

Sunday and Monday, this blocking pattern enabled warm air to flood north into Alaska, setting off a record heatwave there. You may not think of 50 and 60 degree temperatures in Barrow, Alaska as a heatwave. But when average highs for June there are about 38 degrees, 50 and 60 degree weather is quite hot for this time of year.

Last Thursday saw temperatures in Barrow above 60 degrees. Today, so far, temperatures have risen to 52 degrees, though the high will probably not be reached for a few hours yet.

All this warmth is doing a number on sea ice in the region. As I posted yesterday, large, dark melt ponds and holes in the ice are now visible off Barrow. You can see them in the most recent Barrow Ice Cam shot below:

Barrow sea ice June 18

(Image source: Barrow Ice Cam)

Note the near-shore melt  as well as the large, dark holes forming and widening off-shore.

The pulse of warm air riding up into Alaska is common to a warmer air mass now pervading much of this region of the Arctic. As a result, above freezing temperatures have now invaded large sections of the Beaufort, Chukchi, and East Siberian Seas. This warmer air is causing melt ponds to form over the region leaving their tell-tale bluish tint in the satellite pictures.

Melt Ponds Beaufort, Chukchi, East Siberia

(Image source: Lance-Modis)

In the above image you can see this bluish tint covering about half of the Arctic Ocean area represented in the picture. Also note the large and rapidly expanding area of open water north of the Bering Strait and the large and expanding cracks over the East Siberian Arctic Shelf.

Ice of this color indicates a speckling of melt ponds and hints at the ongoing impacts of solar insolation on the sea ice. Warm conditions in this region have favored insolation for at least the past week. And persistent warmer, clearer weather is beginning to enable the sun to do some serious work on the sea ice.

Warmth is expected to continue for this area until at least next week. The latest long-range forecast from ECMWF shows above-freezing and even 50 degree temperatures plunging deep into this region of the Arctic all the way through late June.

Beaufort Warmth Late June

(Image source: ECMWF)

By June 28th we have 40 degree average temperatures extending far off-shore with above freezing temperatures covering much of this section of the Arctic. Melt in this region, therefore, is likely to be greatly enhanced as the sun is provided with an extended period during which to do its work.

Links:

Heatwave Sets Records Across Alaska

Barrow Ice Cam

Lance-Modis

ECMWF

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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

Arctic Sea Ice Melt Continues Past Typical Season’s End

Each year, as the sun begins to fall toward the southern sky, cold air begins to accumulate in the Arctic, bringing an end to the summer sea ice melt season. On average, this date falls on September 15th. This year, the 15th came and went. But a devastating record sea ice loss continues. A loss whose damage to the Arctic cryosphere now rivals that of 2007.

Today, Arctic sea ice extent reached new record lows for both JAXA and NSIDC. JAXA is showing sea ice extent at 3.475 million square kilometers. NSIDC is currently at 3.39 million square kilometers, also a new record low. Sea ice area reached a new record low yesterday with Cryosphere Today showing 2.234 million square kilometers.

Sea ice values are starting to now see very large departures from the record lows set in 2007 and 2011. Departures for the major measures are as follows:

JAXA Extent: -775,000 square kilometers (2007)

Cryosphere Today Area: -671,000 square kilometers (2011)

PIOMAS Volume: -400 cubic kilometers (2011)

NSIDC Extent: -780,000 square kilometers (2007)

Losses for sea ice extent are 19% below the record low level set in 2007. Losses for sea ice area are 23% below the record set in 2011. These percent losses are very close to the massive declines seen in 2007. With values now approaching 800,000 square kilometers, totals for 2012 are also now nearing the 1.1 million square kilometer losses experienced in 2007. At current rates of loss, it seems unlikely that 2012 will break much more than 800,000 square kilometers below past records. However, as the days go by, the 2012 melt season continues to surprise.

It appears that above average temperatures for this time of year are at least partially responsible for the ongoing melt. During a time when temperatures should be rapidly falling, they are, instead, remaining about level. Current average temperatures for the Arctic environment above the 80th parallel are now about -1.5 degrees Celsius. Though this temperature is below the freezing point of fresh water, salt water tends to freeze at -2 degrees Celsius. The result is that the balance of the Arctic environment is still tipped toward melting.

This sustained high temperature trend can be viewed in the graph below, provided by the Danish Meteorological Institute:

And you can see well enough that these temperatures are becoming more and more anomalous as September continues.

In addition, it is worth noting that weather conditions do not appear to particularly favor melt. In fact, we’ve just passed through a set of conditions that would have favored stabilization or freezing in a normal Arctic year. So it would seem that increasing heat content in the Arctic environment is the most likely culprit for this year’s melt.

Before I close out this blog for the evening, I’d like to let you know that I’m in Myrtle Beach, South Carolina for a one week vacation with family. We’re currently renting a beach house on the ocean and, for whatever reason, the beach directly in front of the house is terribly eroded. Only a small dune protects the house from what seems to be a hungry sea. In addition, at high tide, twice each day, the ocean waves come lapping up against the dunes. So, with each passing high tide, more and more sand is washed out to sea.

Earlier today, my wife and I went for a walk along the shore. On this particular walk we encountered not less than five homes which appear to have sustained damage from the encroaching seas. A number of other homes shelter behind sea walls. One house had an enormous pile of sand dumped in front of its property. It seemed that this sand had been deposited there by a dump truck as a measure to prevent an inflow of the encroaching seas.

A large tide pool had formed directly in front of some of these imperiled homes, replacing a normal dune line and undercutting beach walkways.

I’ll do my best to get pictures for tomorrow’s blog so you may have a visual reference. In any case, I find it somewhat ironic that a location my family chose shows such obvious effects of rising seas.

Links:

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

http://ocean.dmi.dk/arctic/meant80n.uk.php

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

https://sites.google.com/site/arcticseaicegraphs/

IPCC Melt Predictions Left Behind By Arctic Death Spiral, Many Scientists Now Predict Ice Free Arctic in 3-20 Years, Rapid Melt from Greenland, West Antarctica Imminent

(IPCC graphic of Arctic sea ice change from 2006 to 2080-2100)

For sea ice melt trackers, 2007 was a long, long time ago. Things were quite a bit different then, before that record year obliterated all past records for sea ice loss and made projections like the one above seem silly and quaint. Since these predictions were made, we’ve lost nearly 2 million square kilometers of sea ice — an area nearly the size of Greenland and melt rates indicate an end to Arctic sea ice by late summer within the next decade.

If such an event were to occur, it will happen more than 60 years ahead of IPCC predictions. As an aside, it is worth noting that the graph doesn’t represent what a small remnant of sea ice will probably look like. The actual north pole will be free of ice and all that remains will huddle against the north of Greenland for protection and insulation from the insults of heat from all directions.

As the record melt season of 2012 has continued to progress, more and more Arctic scientists are validating a melt trend that is devastating the northern polar sea ice. PIOMAS has been collecting data that shows a potential for sea ice disintegration by end of summer within the next 5-10 years. And this summer a team of British researchers validated PIOMAS findings using satellite data. Then, Cambridge professor and sea ice expert Peter Wadhams made a stunning prediction that most sea ice could be gone by 2015.

Now, the Norwegian Polar Institute is chiming in. The Arctic sea-ice big melt of 2012 “has taken us by surprise and we must adjust our understanding of the system and we must adjust our science and we must adjust our feelings for the nature around us”, says Kim Holmen, NPI international director.

“As a scientist, I know that this is unprecedented in at least as much as 1,500 years. It is truly amazing – it is a huge dramatic change in the system”, noted NPI’s Dr Edmond Hansen. The melt is “not some short-lived phenomenon – this is an ongoing trend. You lose more and more ice and it is accelerating – you can just look at the graphs, the observations, and you can see what’s happening.”

What has happened is that nature is moving the goal posts faster than scientists can establish them.

The heat we are seeing doing work on the sea ice now. What will happen to it once it has finished with the sea ice? It’s not just going to sit there in the ocean for decades and centuries. It’s going to go right to work on Greenland. And we can see that happening now. According to scientific reports, the tipping point for Greenland ice melt is between .8 and 3.2 degrees Celsius above pre-industrial average. We are at .8 C now. And the forcing of human climate change keeps pushing that number higher.

This summer saw a massive new record melt for Greenland and it’s really just the beginning.

IPCC findings were for a very mild sea level increase for the 21rst Century. However, with the sea ice melting so fast and Greenland and West Antarctica next in the line of fire, it appears that these break-downs are more and more likely to occur sooner. Possibly starting within this decade and intensifying through mid century. It is more likely that a 2 meter rise or greater will occur before 2050, if greenhouse gas emissions aren’t dramatically brought into check. And based on where we are now, it would take a major effort to remove carbon from the atmosphere to prevent sea level rises in excess of 1 meter by end of century.

As we’ve noted in previous posts, a 365-405 ppm level of CO2 is enough to melt both Greenland and West Antarctica and raise sea levels up to 75 feet. We are in this range now. Yet with current emissions and amplifying feedbacks from traditional carbon sinks, it looks like we are on track for between 450 and 550 ppm CO2 by mid-century. At 550 ppm CO2, there is enough heat energy in the atmosphere to take out all the ice sheets.

This is a very powerful forcing that will almost surely have gone to work substantially softening Greenland and West Antarctica by the period of 2040-2060.

The goal posts are moving swiftly and it is fair to say that human-caused greenhouse gas emissions are both knocking Earth out of its comfortable homeostasis as well as knocking the once static and slow-seeming study of climate into a period of rapid change.

Links:

http://thinkprogress.org/climate/2012/09/13/841881/arctic-warning-as-the-system-changes-we-must-adjust-our-science/#comment-478091

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