Arctic Sea Ice

ASI 2015 update 4: massive heat

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2014 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

July 7th 2015

I wanted to wait for the latest PIOMAS update and do another melt pond analysis for June, but given the current circumstances and the forecast I've decided to squeeze this ASI update in first.

As we've seen in previous ASI updates this melting season hasn't had a flying start, but it hasn't been as slow as 2013 and 2014 either. With extent going low real fast, but area lagging behind, the compactness numbers indicated little melt pond formation and no divergence to speak of. Melt ponds - and to a lesser extent openings within the ice pack - are important because they lower the ice pack's albedo and soak up a lot of sunlight, preconditioning the ice for further melting. This melting momentum, as I call it, can play a decisive role in the latter half of the melting season, trumping weather conditions.

Of course, weather still plays a very significant role in the final outcome of a melting season. This year hasn't seen any substantial preconditioning and is more similar to rebound years 2013 and 2014 than record years 2012, 2007 and 2011. In fact, this year has been very much like last year, in the sense that there is hardly any movement. Very little ice is transported through Fram Strait to the North Atlantic ice graveyard, and there is no compaction or divergence to speak of because of a lack of strong winds. Most of the extent/area decrease is caused by so-called in situ melting, or melting on the spot.

However, there is one big difference compared to last year and that's heat. Despite a very cold start, there have been several outbreaks of warm air over the ice, slowly but radically shifting the balance between extent and area data. The impact is felt on the surface of the ice pack, but doesn't translate directly into a decrease. Not yet. In theory, it should percolate through after a while, especially if the heat persists. And right now the Arctic sea ice pack is undergoing a massive heat wave which shows no signs of letting up.

More on what has happened and what is going to happen below.

Sea ice area (SIA)

Here's the latest Cryosphere Today SIA chart, to which I've added preliminary data as calculated by Wipneus:

Big drops have been alternating with small upticks, keeping the trend line near the upper half of the pack, but below that of 2013 and 2014.

ASI 2015 update 2: take me to the other side

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2014 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

June 4th 2015

Usually, not always, if one thing is going on in the Arctic, the opposite is happening on the other side. In fact, something like it - albeit in the longer term - is mentioned in the latest NSIDC monthly summary:

[A] new study shows that when winter sea ice concentrations are above average in the East Greenland, Barents and Kara seas, ice concentrations tend to be below average in the Bering Sea. This spatial pattern of anomalies linking the North Atlantic and North Pacific is related to the sea level pressure pattern that drives surface winds and their associated movement of atmospheric heat. These conditions are in turn linked to cooler or warmer than average sea surface temperatures that provide memory, influencing regional sea ice concentrations the following autumn. Thus, while the atmosphere is critical in setting the spatial patterns of sea ice variability, the ocean provides the memory for reemergence.

As I wrote two weeks ago in ASI 2015 update 1, the melting season started early in the Beaufort and Chukchi Seas, but while the multi-year ice was getting its first beating of the melting season, the ice in the East Siberian and Laptev Seas was still in deep freeze. This resulted in relatively thick ice (see the latest PIOMAS update released earlier today) and a delay when it comes to melt onset in that quarter of the Arctic.

But as always, things have started to flip, and the action is being transferred to the other side. Below I'll explain the details and the forecast for next week. Also be sure to read RobertScribbler's take on the matter when you're done reading this update, as he also covers snow cover, which, to quote from this article in the Washington Post, "unlike sea ice, gets no attention".

Sea ice area (SIA)

Although Cryosphere Today has been updating on a daily basis again, I've taken the liberty of using the latest two pre-calculated data points by Wipneus so that I can show the June CT SIA map:The 2015 trend line is clearly in the bottom half of the pack, but it refuses to follow the order that has been clear on sea ice extent graphs for several weeks now, as seen below.

ASI 2015 update 1: early start in Beaufort

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2014 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

May 19th 2015

Here it is, the first Arctic Sea Ice update for the 2015 melting season, and boy, are we off to a flying start. But more about that later. First a quick overview of what's been happening the last few years.

After the 2007 melting season smashed the 2005 record minimum, it was equalled by the 2011 melting season and subsequently smashed itself by the 2012 melting season. Although the 2013 melting season didn't bode well at all, given the trend and the massive amount of first-year ice, the Arctic sea ice had its traditional post-record rebound after a cold and cloudy melting season.

This (volume) rebound had all but vanished at the start of the 2014 melting season, but again the melting season started out cold and cloudy, after which the sea ice hardly moved during the rest of the melting season. And so there was a similar rebound to the one following the 2013 melting season. However, this time the volume rebound was larger and lingered on through winter.

One would think the ice pack would be strengthened and more resistant to weather conditions at the start of the 2015 melting season. But this also depends on how the volume is distributed across the pack, and as we saw in the 2014/2015 Winter analysis I posted 10 days ago, all of the volume has piled up in the Central Arctic and the Canadian Archipelago, the sea ice's last safe haven. This basically means that as far as the periphery of the Arctic sea ice pack is concerned, there is no big difference with the other post-2007 years. This melting season could turn out to be another rebound, but it might just as well go as low as 2007, 2011 or even 2012. The only thing we know for certain, is that the Arctic won't see below 1 million km2 of sea ice come September, the definition of 'ice-free'.

The outcome is obviously determined by weather conditions, but this month and June are particularly important for what I like to call melting momentum. This momentum is determined by the amount of melt ponds that form on the ice pack during these two months, as they soak up more solar energy that would otherwise be reflected. 2012 had a relatively sunny and warm start of the melting season, after which a stable decrease couldn't be thrown off by weather that was less conducive to melting. And that's how the record was broken, compounded by the Great Arctic Cyclone in August. Conversely, 2013 and 2014 had cold and cloudy starts to the melting season, and this couldn't be made up later on during bouts of sunny weather.

And so melt ponds will be the main theme of this first phase of the melting season. In fact, I'm going to obsess over them in the next two months and report on them outside of the ASI updates. The amount of melting momentum decides whether the melting season has a chance of breaking records.

Off we go.

Fringe fries part 2

This is a follow-up to the first Fringe fries post from 3 weeks ago. I've compiled a couple of comparisons of Arctic regions, so we can see how 2012 stacks up against previous years. Remember, you can check out the Concentration Maps page on the ASI Graphs website, which is very handy for a quick look to see how out of the ordinary something is, or just to compare the progress of ice decline to that of previous years. If you want to know to what the geographic location of specific regions is, I recommend going to the Cryosphere Today home page. There's a map in the middle left of the web page.

First we're going to have a look at Hudson Bay as the melting is almost finished there. As usual I use sea ice concentration images from the University of Bremen because of their excellent archive(s). Click on the image for a larger version:

Compared to the other big melt years 2007, 2010 and 2011 there is some more ice left in Hudson Bay right now. This is one of those places I referred to as 'piggy bank' in the latest ASI update. As we can see on this regional sea ice extent graph from NSIDC/NIC, 2012 is 100K and 450K square km behind 2011 and 2010 respectively:

Fringe fries

With things looking so serious in the Arctic right now, it was high time for another corny pun!

Instead of doing three different posts, I'm combining three different comparisons of fringe regions for today's date. Of course, I'll be using the excellent University of Bremen sea ice concentration maps. If you prefer the holistic view, you can go to the concentration maps page on the Arctic Sea Ice Graphs site. A reminder from the UB webpage: "As we are using SSMIS data instead of AMSR-E data, the quality of the resulting maps has yet to be assessed." There are probably some differences between this year's SIC map and those of previous years - probably in colouration -, but IMO they're small enough to discard.

Let's start with Bering and Chukchi (click on the image for a larger version):

2012 seems to have made up the deficit and looks very similar to all other years except 2011. Which is not surprising as the Bering Sea is almost devoid of ice. Yes, all that ice that was used to mislead a couple of extra people here and there in some quarters, is now gone. On the MASIE chart we can see 2012 right in there with the other years, except for 2011 diving down: