2013/2014 Winter Analysis

With another interesting freezing season behind us, it's time to compare to previous winters and get an idea of this melting season's foundation. As we have seen in the last two years, the start of the melting season plays an important role, and so it might very well be that the end of the freezing season plays a role as well (what holds for the Arctic summer often is the opposite during winter). If only for the fact that the end of the freezing season is immediately followed by the start of the melting season. Sorry for being so simplistic.

OK, we'll repeat the format from last year and compare the 2013/2014 freezing season with three other freezing seasons. In this case, I have chosen the last three winters (ie preceding the 2011, 2012 and 2013 melting seasons). No 2007? No 2007. I know it's blasphemy, but we have to move on. Click on the images if you want to see a larger version.

Ice age

It's clear that after last year's 'rebound' the Arctic now contains a lot more multi-year ice than in the last 3 years, as can be clearly seen on these AARI ice age maps for the end of April:

2011's vomiting cow doesn't look all that smaller (the brown colour represents the multi-year ice), but this year's genetically modified mouse is still a tad bigger, with a large bulk of multi-year ice taking up position in the Beaufort and even some of the Chukchi Sea. Whether this will prove to be a protective barrier, as witnessed in 2010 and 2011, remains to be seen.

These ASCAT radar images also show that this year the ice pack contains a lot more whiter ice. Here's a comparison for day 109 (April 19th):

Ice age doesn't necessarily tell us anything about ice thickness, and the white colour doesn't either. As the NSIDC explains in their latest April summary:

The ASCAT sensor measures the radar–frequency reflection brightness of the sea ice at a few kilometers resolution. Sea ice radar reflectivity is sensitive to the roughness of the ice and the presence of saltwater droplets within newer ice (and, later in the season, the presence of surface melt). Thus older and more deformed multiyear ice appears white or light grey (more reflection), whereas younger, first-year ice looks dark grey and/or black.

Of course, it doesn't mean the ice isn't thicker either.

The NSIDC summary is also accompanied by the yearly ice age distribution map, now provided by Dr. Tschudi from the University of Colorado. I've combined it with the maps from 2012 and 2013 on the right.

Other than a lot of second-year ice (blue) last year, there's also a lot more white (4+ years old) than we've become accustomed to, but a large part of it is now sitting in the Beaufort. If it doesn't prove to be a barrier, it could get lost again. Another reason for this increase in multi-year ice (besides last year's 'rebound'), according to the NSIDC, is "the predominant recirculation of the multiyear ice pack within the Beaufort Gyre this winter and a reduced transport of multiyear ice through Fram Strait maintained the multiyear ice extent throughout the winter".

As we'll see below.

Sea level pressure and ice drift

The movement of ice floes is largely determined by wind, and wind is largely determined by sea level pressure gradients. So let's first have a look at SLP maps from NOAA's Earth Science Research Laboratory (daily mean composites page). I have divided the freezing season up into 3 parts with a duration of two months each:

It seems 2013 was the odd man out, because 2011, 2012 and 2014 look remarkably similar. This, of course, doesn't mean that this melting season will follow those of 2011 (record tie) and 2012 (record smash), but it's noteworthy nonetheless. As it was last year.

I have combined these IFREMER/CERSAT sea ice drift maps to show how the ice moved in the recent October-March period:

 

It indeed seems there hasn't been much transport through Fram Strait, and much of the ice has recirculated, which should improve overall ice quality.

Air and sea surface temperatures

Now to have a look at temperatures. For that we turn again to NOAA's Earth Science Research Laboratory daily mean composites page.

First off, air temps divided into the two halves of the freezing season: 

The first half of the 2013/2014 freezing season wasn't really irregular. Of course, it was very warm in a large part of Siberia, but it's after New Year's Eve that things get really interesting temperature-wise, with record temperatures being recorded in places like Svalbard and Alaska.

This NCEP air temperature map including April shows how temps have been the highest on record in the 70 to 90N area of the globe (from this blog post by Diablobanquisa):

I've made separate temperature anomaly maps for the first three months of the year, and things really look hot (compare for instance to last year):

Of course, this doesn't mean that temperatures were high during January, February and March, it was plenty cold in the Arctic. But the anomalies are very high, and every degree less cold means the ice thickens less. How much less, we don't know, but according to PIOMAS the volume rebound from the 2013 melting season has been all but negated. And the relatively mild temperatures probably have played a big role in this.

It probaby also played a role in the amount of snow cover on the Northern Hemisphere (see for instance March), but we have to wait and see how that plays out.

I don't know how trustworthy SST maps from the daily mean composites page are, but here too the 2013/2014 freezing season really stands out during the second half:

Ice thickness

The Naval Research Laboratory has been sharing several sea ice maps for a couple of years now from their ACNFS model. Although I don't know how reliable their thickness maps are, it's still useful to compare this year's map to those of previous years:

 

A lot of dark red pressed against Greenland and the Canadian Arctic Archipelago, but a lot of blue as well, and again we see all that yellow towards the Alaskan coast.

Another source of information comes from the SMOS satellite (see this blog post from 2012) that has been validated extensively the last couple of weeks during various missions in the Arctic. The data has been converted by commenter Wipneus - who regularly posts SMOS updates on the Arctic Sea Ice Forum - and compared to the previous three years:

Keep in mind that SMOS can only measure ice up to 0.5 metres, and the differences with previous years are minute, but it's a comparison and that's what this blog post is all about.

I'll finish with another graphic produced by Wipneus and posted on the ASIF, this time depicting the change in thickness compared to 2013, as produced by the PIOMAS model:

This clearly reflects the ice drift maps from above, with ice being pushed from Siberia to Greenland and the CAA, leaving thinner ice in its wake. It suggests to me that the Northern Sea Route could be opening up again, but perhaps the Northwest Passage remaining closed for a second year in a row.

Conclusion

Personally, I don't think the 2012 extent/area record will be broken this year, just like 2007 was followed by a couple of 'rebound' years. The bastion of older ice has been re-inforced, although part of it has moved out into a zone where it could be either vulnerable or hang on long enough to prevent any records.

Still, given the PIOMAS volume wipe-out and the high temps during the latter half of the freezing season, I do see how this year's minimum could come close to or even surpass that of 2012. Of course, it all depends on what the weather does. And the start of the melting season is very important as well.

I hope you enjoyed this quick overview. I will soon start posting regular Arctic Sea Ice updates, because there are already lots of interesting things going on. Check the Arctic Sea Ice Forum if you can't wait for the updates (ignore the safety warning).

Comments

[John Christensen]

Thank you for a great analysis of development during the winter months, Neven.

I agree with your conclusions, and that we should expect minimum area and extent to be in the range between 2012 and 2013, i.e. be close to 2010 or 2011.

DMI has an extent graph
http://ocean.dmi.dk/arctic/icecover.uk.php
(based on OSISAF), which is interesting, as it seems to show the importance of the direction of the extent in early-mid May: Extent by late April apparently having little impact on summer extent (see 2012), while it does become increasingly important to retain extent by mid-May, as it impedes sun radiation in reaching waters of the Arctic seas (since by mid-May edges of the Arctic Basin are starting to open up). From the DMI graph we are a bit low on extent this year, and with warm air being pulled in across the Beaufort, in addition to ice being pushed offshore in Laptev), it seems weather will need to be even more favorable this year to have a repeat of last years reduced melting, allthough ice quality has improved somewhat.

For PIOMAS, I would expect we have caught up with 2013 again since we last year had more ice in Okhotsk and Bering, which has dropped fast in prior weeks, and also the 80N temperature in the past month has been quite similar to 2013.

The forecast shows a cyclone entering the basin from Bering/Beaufort in the next couple of days, pulling air north from the CAA and Greenland, and it seems a solid high is also getting in place on the Central Siberian Plateau (CSP), pushing the jet stream north across Laptev and ESS - just weather or early indicator of repeated pattern from last year?

[Kevin McKinney]

Yes, thanks, Neven! Appreciate the work and thought. So far, it does look as if we might see a 'reversion to trend' sort of year… but we all know about the Arctic's ability to surprise.

[D]

Excellent summation, Neven but you have downplayed the strong transport of oceanic heat under the ice on the Atlantic side of the Arctic ocean this year. The heat, which was apparent on the SST maps from late fall & early winter of this year, has gone under the ice and will add extra heat from below during this melt season.

It doesn't look good for the Siberian side of the ice pack this year. The Canadian side looks thick and the Beaufort has more multi year ice, but El Nino and very warm water in the far north Pacific are already beginning to attack the ice in north of Alaska.

I think we are going to have a major volume loss year like 2010. We'll challenge 2012 for area and extent but that will depend on the weather & compaction.

The SSTs in the northern hemisphere are already ridiculously above normal and El Nino hasn't even been declared yet. All that warm water is like kryptonite for the sea ice. By September, 2015 I predict that sea ice levels will crash well below levels seen in September 2012. If the ice holds out this summer then the crash will happen in summer 2015. Much warmer than normal waters in the far north Pacific and Atlantic will inevitably take their toll by both transport into the Arctic and the transport of extra water vapor in the atmosphere, which will cause more trapping of incoming solar energy by the greenhouse effect and clouds.

[plus.google.com/102121405461486954917]

The climate was stable during Roman times and past ice would predict future ice. Then we had LIA and MWP. Now we have AGW. Each year we have measurably more heat in the system, and the system collecting heat faster. It is a heat engine with the throttle pushed a little bit forward each year.

Each year the engine runs a little differently as a result of the increased energy in the system. Since the energy of the system changes each year, past system behavior does not predict future system behavior. Since this is the first time we have observed the climate system under these conditions of changing heat levels, we cannot be certain how the system will respond. In particular, we are ignorant of system lags and feedbacks. At this point we know the system is going to a state with less ice than humans have ever seen before, and it is going there faster then we have ever seen climate change.

I remain convinced that the Arctic ice will retreat in a series of abrupt ice loss events, and that each successive event will produce gasps of surprise from the assembled observers.

[TenneyNaumer]

Looks like the cyclone is already forming in the Beaufort:

http://weather.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

[R. Gates]

It will be interesting to watch what this cyclone does to this still thick spring ice pack. Looks like it may pull in some warmer air for sure, and pull ice further away from the coast off N. Alaska:

http://earth.nullschool.net/#current/wind/surface/level/orthographic=-87.41,86.93,782

[John Christensen]

@R. Gates,

You should check Neven's entry from last year on summer cyclone behavior: This cyclone does not have similar behavior to a tropic cyclone (other than the anti-clockwise rotation), since compared to surrounding air masses it does not contain warm humid rising air at the center.

As it simply circulates with fairly stable vertical air masses at the center, it will break the ice where the ice is weak enough to be broken and the breaking of the ice would assist in dispersing the ice. At the center of the cyclone, the ice will break down faster with stronger winds/lower pressure, as the mixing with top water layers increase.

Overall, however, as we saw last year the cyclonic pattern tends to conserve the ice, apparently due a mix of factors:
- Blocking of sun radiation/cloud cover
- Sligthly lower temperatures (cyclone isolates Arctic air mass from surrounding warmer air masses)
- Increased albedo, as consequence of ice being dispersed (this is probably more speculative, but it seemed from last year that even the thin ice cover had a significant impact in preventing top water layers from warming. And as has been shown elsewhere, heated top water is excellent for melting nearby ice)

Forecasts have the cyclone staying more or less in place for the next week, so will be interesting to follow.

[wayne]

John, I would add, Cyclones bring up substantial heat from the South, Alaska and Yukon are very warm, the clouds reflect back sea water thermal losses until the surface temperatures are quite the same as sea water. But general circulation appears unlike last year, the Beaufort area and AA has more often than not a high pressure system hanging about. Circulation wise, looks much like 2012 on steroids provided by EL-Nino. Ice wise 2007 ice thickness was thicker and vanished in the Basin, I foresee 2007 type melting as well.

[Blaine]

After a very warm Arctic Ocean winter, total sea volumes on the eastern side of the Arctic are very near the record low levels of 2012, with the Laptev sector setting a new record low by quite a lot. On the other hand, sea ice on the western side remain relatively high for recent years, pretty much entirely as a carryover from the cold winter and cloud-covered melting season in 2013. One particular thing to note is the extreme ice compression against the Beaufort shore this winter. Ice levels in the nearshore Beaufort are by far the highest of any recent year, while ice levels in the northern Beaufort are at a record low by a small amount.

This distribution favors extreme late-summer meltoff of the Beaufort, which will of course depend on weather as well. The near-shore Beaufort will likely melt out anyhow despite thicker ice, and the northern Beaufort is more likely to melt out with thinner ice.

The GFS forecast shows a storm center basically staying put over northern Chukchi and the northern Eastern Siberian sector or close to the pole, while the Beaufort stays in the warm sector of the storm and gets torched. This is quite different from the weather of most of the latter part of the melting season in 2013, which was mostly storms centered in the southeastern Beaufort and the CAA, which allowed relatively little melting in the Beaufort. We should see relatively little melting from this, initially, because of the thick ice close to shore, but it does set up a large melt out there later in the year. It also sets up the high Chukchi and Eastern Siberian sector as being less likely to melt out completely.

El Nino is here in earnest now, regardless of whether or not the CPC is putting out press releases about it yet. California and the southwest US can really use a good El Nino now, since they haven't had one in far too long and are way too dry.

[VaughnA]

PIOMAS has updated. Max ice volume was 22,900km^3...2nd lowest on record and just 400km^3 above April 2011. It is setting out to be an interesting melt season.

[Neven]

Thanks, VaughnA. PIOMAS update is up.

[John Christensen]

Sorry for deviating from topic, but with the impressive development in Antarctic SIA, it would be very interesting to see sea ice volume numbers from down under, but I assume this data is not being tracked?

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html