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Delving Further into Uncharted Territory: Arctic Sea Ice Greatly Weakened at Start of Spring 2018

The story of Arctic sea ice is one of short term complexity overlying an inexorable long term trend of decline. It has thus been difficult for sea ice monitors to forecast seasonal ice growth and retreat, despite a larger and significant warming of the Arctic.

(New ice has formed north of Greenland following a massive polar warming event last week. This ice is thin and faces the warm up of spring and summer with uncertainty. Sitting over a region that is typically filled with thick ice, it could provide a back-door for melt into the Central Arctic come summer. As usual, weather will play a key role in this year’s melt, despite the undeniable longer term trend of loss. Image source: NASA.)

Undeterred by these facts, a number of key factors stand out in 2018 — following a winter in which the Arctic has suffered considerable warming and related impacts to the ice.

Lowest Sea Ice Extent; Warmest Freeze Season

Today, Arctic sea ice extent is at its lowest levels on record. Volume, is at the second lowest levels ever measured. And this year’s freeze season (October through February of 2017-2018) was the warmest ever recorded (see link below). Taken at face value, these are pretty stark statistics. But they don’t tell the whole story. Not by a long shot.

The Arctic is warming up twice as fast as the rest of the world. It has been doing so since around 2000 when Polar Amplification — the science-based expectation that the poles will warm faster than the globe as greenhouse gas levels rise — really began to kick in. So the present warm peak in the Arctic is on top of a record spate of accelerated warming. In the graphs it looks like a rocket ship taking off.

We should be clear that most of this warming has occurred during winter time. It’s warmth that has softened the ice, thinned it. Produced a big push toward thaw. But like a cup of water with a single cube of melting ice in it will resist surface temperatures above freezing, this thinning and melting has yet to have have a significant impact on summer-time temperatures in the high Arctic. That thinning skein of ice is still doing its duty keeping the Arctic summer close to freezing. But it’s a realistic question to ask — how much longer can it? What happens when the majority of the summer ice is gone?

Such radical warming has also had a number of environmental effects. It is pushing fisheries that rely on cold water northward. It is stressing key species like the Wright Whale, the Polar Bear, and the Puffin. It is causing the permafrost to thaw, which produces a number of environmental feedbacks. Not the least of which includes land subsidence, the release of mercury into the Arctic environment and global ocean, and the slow but rising expulsion of greenhouse gasses long locked away.

Multiyear Ice Has Pulled Away From Shore

The thicker ice floes of yore are now mostly a bare memory. A recollection of past cold blasted away by fossil fuel burning and inexorable thaw. This year, an LNG tanker crossed the thinning ice during winter time. Bearing with it a great load of climate change quickening gas destined to be burned in some nation still entangled by a heat-producing web of gas plants, coal mines, and diesel and gasoline cars.

The thick, multiyear ice is reduced to a phantom of its former girth and extent. It has drawn back, pulling away from shore. Increasingly sequestered to more and more remote regions. And on the run from the ocean swells, warmer storms, and increasing instances of liquid rain that fall across an Arctic that is facing violent transition.

Increasingly, it huddles closer to Greenland and the Canadian Archipelago. But as we can see in the image at the top of this post, even this region is no longer a reliable sanctuary.

Cold Pole Shift in Forecast — Canada/Alaska Predicted to See Abnormal Warmth

As late winter transitions into early spring, we enter the less certain time of melt and thaw season. During recent years, as warming bloomed in the lower latitudes, the Jet Stream which had slowed and meandered more during winter due to polar warming, snapped back into place. This seasonal flattening and speeding up of the upper level winds tended to harden and deepen the cold pole at the north of our world. Reducing relative temperature variance above normal averages even as melt season advanced.

This created a kind of Dr. Jekyll and Mr. Hyde relationship between winter and summer in which high Arctic winter temps seemed outrageously warmer than normal even as summer snapped back to more typical Arctic averages in the furthest north locations.

(As we enter spring and summer, high Arctic temperatures tend to regress back toward the mean following winter warming. This is largely due to the inertial cooling influence of ocean ice which will tend to keep temperatures closer to the freezing line even as net energy gain is ongoing. Loss of ice would result in the removal of this insulating effect and likely push summer anomalies for the region into the +1 to +5 C range. Image source: Zachary Labe. Data Source: DMI.)

But all is not well. The loss of winter climate norms have done their damage. And the summers, on balance, saw the edge ice retreat a bit further. Saw the boundaries of Arctic cold pull a bit tighter and saw the open, warmer, sunlight-capturing waters advance ever northward.

We don’t know if this return to more normal temperatures for the high Arctic during summer will save the ice from new record lows this year during melt season. But we can track how thaw season is predicted to advance against a greatly weakened Arctic sea ice pack. And this year, the cold pole appears to be expected to shift over the land mass of western Siberia during early March.

(A warm North America, cool west Siberia dipole appears to be developing during early March in the forecast models. If this trend reinforces, it could leave large areas of ice open to early thaw from the Alaskan and Canadian maritime to the Central Arctic. Note that residual energy transfer along ocean zones remains in play in this forecast. Image source: Climate Reanalyzer.)

Meanwhile, on the North American side, abnormal warmth is predicted to advance through Alaska, Western Canada, and the Hudson Bay region.

If this trending location of warm and cool extremes reinforces and holds through melt season start, we can expect the front of melt advance to begin on the North American side as the region near the Kara and Laptev seas resist melt advance longer. Meanwhile, latent warmth over the Bering Sea and Svalbard appear to be set to hold back late season refreeze in these two key zones.

How this weather dynamic plays out will determine if melt season 2018 begins on a record low ramp and how resilient the ice will be to the seasonal thaw that is on the way. We are presently in a situation where a record low start is possible even as reasonable concerns about a potential rapid summer melt progression are presently heightened.

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Arctic Sea Ice Area Drops 340,000 Square Kilometers in Just One Day

Sea ice researchers like to talk a lot about what they call ‘Century Drops.’ Days when Arctic sea ice area or extent values fall more than 100,000 square kilometers. In the past, daily Century Drops were relatively rare — with steepest rates of loss occurring during late June through early August and featuring, perhaps, a handful of days in which 24 hour losses exceeded 100,000 square kilometers. But the record melt years of 2007 and 2012 showed a proliferation of daily drops that exceeded the 100,000 square kilometers daily threshold.

Well, a couple of days ago a three Century Drop showed up in the Cyrosphere Today measure. And it may just be something we’ve never seen before (UPDATE: actually the last time was 2008, see Neven’s comment below). At the least, it’s an event that’s pretty amazingly rare — or it should be, without the heat added to the Arctic by human fossil fuel emissions.

On Tuesday evening, the Cryosphere Today site showed Arctic sea ice at about 8,986,000 square kilometers. The next day the measure stood at about 8,646,000 square kilometers. That’s an extraordinary loss of 340,000 square kilometers in just one day.

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(Cryosphere Today sea ice graph shows that losses basically went vertical on Tuesday, June 16. Image source: Cryosphere Today.)

340,000 square kilometers gone in a single 24 hour period. That’s an area of sea ice the size of the state of New Mexico gone in a single day. In the above graph, you can see the drop as the vertical turn in the yellow line denoting 2015.

The massive single day drop temporarily brought sea ice area in the Cryosphere Today sea ice area chart into the range of second lowest on record for the date. Area losses of around 70,000 square kilometers for Wednesday resulted in a retreat to around 4th lowest on record. But any period in which drops of this size become frequent would easily transport the measure into new record low territory.

Arctic Melt Ponds

(LANCE MODIS showing the tell-tale blue of melt ponds all over the Arctic Ocean and most concentrated in edge zone regions. Proliferation of melt ponds during early season, especially when combined with the impact of human caused global warming, can increase risk for new record lows by end season.)

The cause of such a large single day drop is likely due to a combination of factors. Lately, storms have been more prevalent in the Arctic Ocean proper and such storms have a tendency to spread the ice out more, opening gaps in the ice called polynyas which tends to push the sea ice area measure lower. In addition, there is melt pressure now in Baffin Bay, Hudson Bay, the Kara Sea, the Laptev Sea, the Beaufort Sea, the Chukchi Sea, The East Siberian Sea, the Canadian Archipelago waters, and in the Barents border region. This basically composes the entire border zone of the Arctic sea ice.

Finally, the NASA MODIS satellite composite for recent days has shown a marked shift toward a light blue coloration for the entire Arctic Ocean zone and especially for the border zones. Such a shift is indicative of a proliferation of melt ponds. Major snow cover losses over sea ice during the past two weeks have removed insulation to the sea ice pack and probably aided in the formation of these melt ponds. Melt ponds are a strong indicator for sea ice health throughout the melt season — so a proliferation of melt ponds at this time may be a sign of sea ice melt vulnerability (see more over at Neven’s Arctic Sea Ice blog where they do a bang-up job tracking seasonal melt ponds and their potential impacts).

Though a three Century drop occurred, melt overall still has some catching up to do to make 2012 levels. So though this massive daily drop occurred, we are not yet in the red zone for sea ice area. Sea ice extent measures, on the other hand, remain in the range of second to third lowest on record and are still very close to all time record low levels. So this particular melt season is certainly one to still keep watching.

Links:

Cryosphere Today

LANCE MODIS

The Arctic Sea Ice Blog

Hat Tip to Neven

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

Sea Ice Extent at 3.71 Million Square Kilometers; Sea Ice Area at 2.49 Million Square Kilometers

Over the weekend, sea ice declined to new record lows hitting 3.71 million square kilometers for extent and 2.49 million square kilometers for area. In addition, PIOMAS showed sea ice volume has also reached new lows.

Trends for sea ice extent decline has been especially pronounced this year with values now 524,000 square kilometers below the record set in 2007.  The rate of extent decline is still very steep for this time of year. Usually, melt rates tend to taper off by late August. But we haven’t seen a gradual slowing of melt yet.

September 15 is the average end date for sea ice melt. But with rates of decline still remaining high, melt may extent beyond the normal end date for summer melt. You can view this precipitous rate of decline in the JAXA graph below:

Looking at the sea ice from the satellite picture, we can see a large area of thick ice in the Laptev Sea surrounded by open ocean and thinning ice. It appears that, if melt continues in this region. This large chunk of ice may break off from the rest of the sheet. If this happens, it will be the second such detachment to occur this summer. Detached ice tends to melt quicker than ice connected to the larger mass. So this region may provide a final significant melt for 2012.

In a previous post here, it was estimated that sea ice area could end in a range of 2.1-2.7 million square kilometers and that extent could end in a range of 3.5-3.9 million square kilometers. Current melt is now in the middle range of both of these measures and still falling. So it would appear that end melt will likely be somewhere near the lower range of estimates. If this happens extent and area measures will have been broken by about 700,000 square kilometers by end of season.

Links:

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

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

http://nsidc.org/arcticseaicenews/

http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

Arctic Sea Ice Still Fading Fast, Extent Record to Fall Within Week if Melt Rates Continue

Image

This is what 32 years of human-caused climate change does to a polar ice cap. The first frame shows polar sea ice from August 20th of 1980, the second frame shows polar sea ice from August 20th of this year. The precipitous fall in size is horrific. Many in the climate community are calling it a ‘Death Spiral.’ And I think that’s a very apt name for what is happening to our ice cap.

Today, sea ice area records reached a new all-time low of 2,742,000 square kilometers. This is 163,000 square kilometers below the previous all-time low. At the current rate of melt, we are on track to fall somewhere between 2.1 million and 2.6 million square kilometers of sea ice area by the end of this season. Since this season has shown such a rapid rate of melt, all bets may well be off for the final number.

Image

Sea ice extent also continued its rapid plunge with the Japanese Space Agency (JAXA) showing a loss of 80,000 square kilometers from its extent totals just yesterday. The current total for sea ice extent, according to JAXA, is 4,405,000 square kilometers, this is about 230,000 square kilometers above the all-time low. Given the current rate of melt, JAXA will likely see a new record set within the next five days.

Image

NSIDC is also showing a rapid fall to a new record low for sea ice extent with values coming in very close corollary to those provided by JAXA. So given the current rate of decline, we will also expect to see new records within five days from NSIDC, should melt rates hold.

It is worth noting that the pace of sea ice decline for these observations is still very high. If the season follows typical trends, we should begin to see numbers slowing their rate of decline within the next couple of weeks. However, since weather conditions in the Arctic continue to favor melt and consolidation of the sea ice, it may be possible that we maintain steep melt rates longer than for a typical year.

A few final points for today’s update…

We typically follow only the major sea ice tracking organizations: Cryosphere Today, The National Snow and Ice Data Center, and The Japanese Space Agency. For sea ice volume, the only tracking organization is PIOMAS. However, there are, in total, nine agencies that use different metrics to track sea ice. According to Neven over at the Arctic Ice Blog, four of these metrics are now showing new all-time record lows for this melt season. Neven noted: “I expect the record on most of these graphs to be broken in weeks to come.”

Current rates of melt would appear to validate Neven’s projection and, if they hold, not most, but all records are likely to fall.

Last of all… Many of you may be wondering why mainstream media hasn’t picked up on the record melt currently underway for Arctic sea ice. Part of the reason may be that there are a diversity of monitoring sources. Generally, primary media sources have used the NSIDC measurement as their baseline. So, as Joe Romm notes in his most recent ‘Arctic Death Spiral‘ article, mainstream media will likely pick up the story of this year’s record melt once the NSIDC record is broken.

Links:

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

http://nsidc.org/

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

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