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First Named Arctic Cyclone to Deliver Powerful Blow to Sea Ice?

The weather models are all in agreement, an Arctic Cyclone is predicted to form over the Beaufort and Chukchi Seas tonight and tomorrow, then strengthen to around 980 millibars as it churns through a section of thin and broken sea ice. The storm is predicted to last at least until Saturday and is expected to deliver gale force winds over a broad swath of thinning sea ice throughout much of its duration.

Arctic.wind.60.cc23

Gale force winds predicted for Beaufort, Chukchi and East Siberia Seas.

(Image source: Arctic Weather Maps)

The fact that this particular storm is forming in late summer is some cause for concern. The sea ice has been subjected to above freezing temperatures for some time. Melt ponds have increasingly formed over much of the Arctic and, since late June, most of the precipitation falling on the Arctic has been in the form of rain. The central ice pack is in complete chaos, with extensive thinning and fracturing surrounding a wide arc near the North Pole and a broad melt triangle full of broken ice and patches of open water extending far into the Laptev Sea. Further, the long duration of sunlight falling on the ice surface and penetrating into the ocean layer just beneath has likely warmed waters below the cold, fresh layer near the ice.

As the storm passes, its strong winds and cyclonic circulation have the potential to dredge up this warmer water and bring it in contact with the ice bottom. Such action can rapidly enhance melt, as we saw during the Great Arctic Cyclone of 2012. Since the brine channels are all mostly activated (with much ice in the region now above -5 degrees Celsius) Cyclonic pumping during storm events like this one can transport sea water directly through the ice to increase the size of melt ponds, to break, or to even disintegrate ice flows.

It is important to add the caveat that this particular storm in not predicted to be quite as long or as strong as the Great Arctic Cyclone of 2012 which, in its first week, coincided with a loss of 800,000 square kilometers of ice. But Arctic weather is nothing if not unpredictable and this particular event could just as easily fizzle as turn into an unprecedented monster.

That said, a number of concerning conditions have emerged just prior to this storm that may result in an enhanced effect on the ice. The first condition is that large sections of the Beaufort, East Siberian and Chukchi Seas are covered in thin, diffuse and mobile sea ice. These conditions are clearly visible in the surface shots provided by NASA/Lance-Modis:

Ice and Open Water North of Wrangel Island

In this section, as in other broad stretches of the Beaufort, the ice is reduced to a kind of slurry in which, as Neven over at the Arctic Ice Blog notes, the individual flows are completely degraded and difficult to make out. This slushy region is in direct contact with a region of mostly open water. Such areas of de-differentiated ice are likely to show greater mobility and enhanced wave action during storms, which puts them at risk of more rapid melt.

Another somewhat ominous note in advance of this storm is a rise in Arctic Ocean temperature anomalies over the past couple of days. NOAA’s surface temperature measure indicates a spreading pool of warmer than normal surface ocean conditions throughout the Arctic. In the region this storm is predicted to most greatly affect, the storm will have the potential to bring such warmer than normal surface waters into more consistent contact with the ice through the mechanical action of waves and by activating the brine channels in the ice. Further, a large pool of much warmer than normal surface water in the Chukchi Sea is likely to be driven deeper into the ice pack where it also may enhance melt.

sst.daily.anomCyclone

(Image source: NOAA)

In general, there’s quite a bit of atmospheric and ocean heat energy for this storm to tap and fling about. Not only is the surface ocean warmer than 1971-2000 base temperatures, but most continental land masses surrounding the Arctic are showing highs between the mid 60s to upper 80s and lows between the 40s and upper 60s.

ECMWF model forecasts show the storm tapping some of this energy in advance of intensification, with a tongue of warm Alaskan and Canadian air being drawn into the storm at the 5,000 foot level late Monday and early Tuesday. Directly opposite, Siberia and Eastern Europe have hosted very warm air masses with daytime surface temperatures above the Arctic Circle reaching the upper 80s consistently over the past week. This warmth also encroaches just prior to storm intensification.

ECMWF warm air advance

(Image source: ECMWF)

Added heat energy injected at the surface and at the upper levels will ensure that the vast majority of precipitation during this event emerges as rainfall.

Broader effects of this storm could be quite significant. The US Navy’s CICE models are showing a greatly enhanced ice motion throughout the duration of this storm as its counter-clockwise circulation is predicted to dramatically increase the movement of the Arctic’s remaining thick ice toward the Fram Strait. The Navy’s thickness monitor also shows a jump in ice thinning and dispersal throughout the ice pack over the duration of this event. In particular, the back end of remaining thick ice north of the Canadian Arctic Archipelago is mashed like a tube of tooth paste in the model run, pushing a broad head of ice toward the Fram. At the same time, a large section of Central ice, earlier thinned by PAC 2013, is projected to rapidly expand and further thin under the influence of this storm.

Note the rapidly expanding melt wave from the North Pole to the Laptev that appears in the final frames of the run below:

 

Arctic Cyclone Daly

(Image source: US Navy)

So it appears we have a short duration but relatively high intensity Warm Storm event predicted to have broad-ranging effects from the Beaufort to the Central Arctic. An event that could have impacts similar to those of the Great Arctic Cyclone of 2012. Should such circumstances arise, it begs the question — is the Beaufort a region that is more likely to spawn these kinds of storms come late July through early to mid August? The region is now surrounded by increasingly warm continents. The observed weakening of the polar Jet Stream by 14% has resulted in a much greater transport of heat to the high continental boundary, as evidenced by a broad swath of heat-waves ringing the Arctic above the 60 degree North Latitude line. The increasingly thin Beaufort ice jutting out into this crescent of continental heat may well be the ignition point for major atmospheric instability, powerful storms and related heat transfer. Something to consider should these kinds of late season ice melters recur on a more frequent basis.

To this point, a new naming convention has been proposed over at the Arctic Sea Ice blog for summer storms that greatly impact the ice. Preliminary standards have been set for storms with a central pressure lower than 985 mb (at peak intensity) and a duration longer than 4 days. Suggestions for storm titles include traditional Inupiat names from this region or even the use of the names of prominent climate change deniers (My opinion is that both calling attention to major Arctic melt events and how climate change deniers have attempted to cover such events up would be an excellent use of such a convention, but I may be out-voted).

You can take part in the naming convention discussion on the Arctic Ice Blog by following this link here.

In conclusion, the potential arises for the first named Arctic Cyclone to result in dramatic melt and weakening of sea ice throughout the upcoming week. This potential heightens the risk for 2013 to be another record melt year and so we will continue monitoring the storm’s development closely for you.

 

 

 

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Greenland Melt Speeding Up; Northern Hemisphere Snow Cover Falling Below Average

greenland_melt_area_plot

(Image source: NSIDC)

Greenland ice sheet melt spiked today, moving into above average territory with nearly five percent of the ice sheet showing surface melt. Influx of warmer air from the south combined with ongoing heat absorption by the ice sheet to push melt levels higher over a broad area of southern Greenland. Temperatures rose above freezing for most of southern Greenland while much colder air remained concentrated to the north.

greenland_melt_nomelt

(Image source: NSIDC)

Over much of the Arctic, warmer air is invading northward. Above freezing temperatures are now common around Hudson Bay, in Northwestern Canada, in Northern Alaska, over sections of the Bering, Beaufort and Kara Seas, and are nearing the coast in East Siberia. Higher temperatures pushing northward have not only set off Greenland melt, but overall Northern Hemisphere snow cover continues to push into lower than average territory.

nhtime-4month

This rapid melt is especially worthy of note considering the massive amount of snow dropped by major storms this winter over much of the Northern Hemisphere. Should pace of snow melt continue, we may be on track for another record year.

Last year, both Greenland surface ice melt and Northern Hemisphere snow melt plunged into record low territory. Greenland melt was particularly exceptional with nearly 100% of the surface area of Greenland showing melt on certain days during July. The last time a similar level of melt occurred on Greenland was more than 100 years ago. A repeat of this kind of melt at any time within the next decade would be unprecedented. However, given current levels of Arctic warming, such melt is certainly possible.

Loss of tundra in certain regions appears to be one of the key drivers of enhanced snow melt during summer time. Arctic warming over the past few decades has continued to push the tundra line northward. As a result, snow is less resilient in northern regions come summer.

Links:

NSIDC

NCEP

Cracks Grow to Cover Large Sections of Arctic Sea Ice as Melt Season Nears

Arctic Cracks

(Satellite image provided by the Canadian Weather Office)

A series of large cracks that erupted into existence in February have now expanded to cover massive sections of Arctic sea ice.

Back in February, a series of large cracks shattered a section of sea ice just north of Canada and Alaska. Since that time, the cracks have been growing and multiplying. Now, nearly all of the Beaufort sea ice is mangled with giant cracks and openings exposing sections of water covered only by a thin film of ice.

You can clearly see a large section of these cracks and openings on the above satellite image just north of Alaska and northwest of Canada.

These cracks now appear to have expanded all the way across the Arctic Ocean to Russia and are fingering eastward toward the Laptev Sea. At this rate, much of the Arctic sea ice will be cracked, broken, and riddled with holes come the start of the melt season sometime within the next few weeks.

This particular event is rare, but not unique. Large cracking events have occurred during late winter and early spring over the past decade. But, according to reports from the National Snow and Ice Data Center (NSIDC), this particular event is the most extensive yet. Considering that NSIDC issued its report a few days ago and that ice has continued its break-up, the current extent of these cracks is even more considerable.

Such a large extent of fractured ice is not a good sign for the upcoming melt season. The ice between the cracks is very thin and, therefore, more likely to rapidly melt. The fractured ice itself has greater surface area and is more at the mercy of the elements — sunlight amplified by global warming and a continuously warming ocean.

Links:

Total Meltdown Warning: High Risk Summer Sea Ice Could Completely Collapse by 2013-2017

http://nsidc.org/arcticseaicenews/2013/03/

http://www.climatecentral.org/news/large-fractures-spotted-in-arctic-sea-ice-15728

http://neven1.typepad.com/blog/2013/03/the-cracks-of-dawn.html

http://dosbat.blogspot.com/2013/03/the-beaufort-break-up-of-february-2013.html

 

Arctic Sea Ice Still Below 2007 Record Low Extent in Many Measures

And so the Arctic refreeze that began on September 19th, after a summer of devastating melt, continues apace. Temperatures are falling throughout the Arctic as the sun dips lower and lower on the horizon, beginning a phase that will eventually result in the total darkness of winter. As you can see on the map above, snowfall is starting to blanket land masses in the region. But an ominously large and dark open expanse of water remains.

Extent, Area Still Close to or Below Previous Records For End of Summer

It is October 5th, 16 days after refreeze began and 20 days after a typical melt season’s end. Yet some measures are still showing Arctic sea ice below past record lows set in 2007. NSIDC and IMS are still showing ice extent values just below the 2007 level. With that record breached on August 25th of this year, we have experienced 41 days, or 11% of the entire year, with sea ice extent values below the previous record low set in 2007.

What this means is that large, dark areas of ocean are having a longer time to absorb heat from sunlight and remain warm for longer periods. What it also means is that a greater degree of endothermic cooling is needed to freeze a much larger expanse of ocean. The result is that much of this cooling work goes to refreeze and less and less goes to thickening the ice. This combination of getting ever further behind the refreeze curve and having to refreeze in a warming ocean sets up the Arctic for even deeper melt in the years following.

All measures show today is a record low for this date in history. Sea ice area is 3.1 million square kilometers below the 1980 value and sea ice extent is currently 3.5 million square kilometers below the 1980 value for today (NSIDC). Sea ice extent is also about 800,000 square kilometers below the record low set in 2007 for today’s date. Sea ice area is about 480,000 square kilometers below the 2007 value for today’s date. These values are roughly equal to the minimum departure seen at melt season’s end. So, though refreeze has begun, the gap, for the moment, remains. However, as the refreeze season progresses, all measures except volume should appear to show some recovery as the ice spreads out with seasonal cooling. We will have to see how much the severe blow that occurred this summer affects overall winter sea ice area, extent, and volume.

New Volume Measure Shows 700 Cubic Kilometers Lost This Year

In my summary post for the epic melt that occurred in 2012 and its implications for melt in the years to follow, I included the final volume measurements for the melt season’s end in September. But it is also worth providing a summary for you here.

Overall, volume fell to 3,300 cubic kilometers, 700 cubic kilometers lower than the record low of 4,000 cubic kilometers set last year. Average yearly volume losses since 2007 are such that, should they continue at the current rate, the Arctic experiences an ice-free state at the end of summer by 2018. Exponential volume loss trends still point toward a potential ice-free state as early as 2015.
These two dates are critical in determining the Arctic’s response both to current melt rates and feedbacks. Should they materialize, we will know that all ice in the Arctic is headed for a rapid melt far sooner than predicted by the major science bodies. And this particular case has very severe implications for Greenland and for world sea level rise.

And a Few Words on Arctic Methane

Arctic methane concentrations will continue to climb through the fall and into early winter. We shall keep an eye on these readings since, as satellite data shows, their concentrations have been growing over the years and because they are one of the number of amplifying feedbacks occurring in the Arctic environment. The size of past pulses and their relative rate of growth is some cause for watchfulness, so we will do our best to track this year’s methane emission peak given the limited tools available.

The most recent methane data for Barrow Alaska is posted below (updated on September 29th, 2012). Note the three outliers at the upper right corner of the graph that caused some concern earlier in September but were confirmed to be from a likely human source. We will also be posting satellite images and comparisons from the University of Maryland as they become available.

Links:

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

http://nsidc.org/arcticseaicenews/

http://asl.umbc.edu/pub/yurganov/methane/MAPS/NH/

http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=BRW&program=ccgg&type=ts

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

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