Arctic Sea Ice

ASI 2016 update 4: breaking point

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. 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 20th 2016

Three weeks have passed since the previous ASI update, but I must say that I haven't become much wiser since then. I was expecting this year to start falling behind on the extent and area graphs, as weather conditions that aren't really conducive to melting, have continued to dominate the Arctic.

More than one month and a half of cloudy weather, not exceptional warm, little compaction, hardly any Fram Strait export, but this year somehow still manages to stay among the lowest on record. Such circumstances would have inevitably led to a major stalling on the graphs in previous years, but not this year. It would seem the lack of melting momentum is being compensated by another kind of momentum, brought on by the mild winter, early melt onset/opening up, extreme low snow cover and anomalously high sea surface temperatures.

The question still is whether this year has the oomph to end up in the top 3 September minimums, but whereas three weeks ago I thought it probably wouldn't, I'm not so sure anymore.

ASI 2016 update 3: crunch time

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. 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 29th 2016

The run-up to this melting season was really special, with an unprecedentedly warm winter season and early opening of the Beaufort Sea. Sea ice extent and area numbers went extremely low for the time of year, and sea ice volume reached the depths it was at before the 2013-2015 post-record rebound. But events in the Arctic don't behave like a straight arrow. Not in the short term, at least.

Weather conditions switched around the start of this month (see previous update) and prevented a large-scale soaking up of solar radiation through leads and melt ponds that would've increased the chances of a new record low September minimum even more. The lack of melting momentum has in fact decreased the chances to the point that I'd bet against it. If you want more details, read these two posts, or this blog post by Chris Reynolds that is hot off the press.

Mind you, this is not a melting season like 2013 or 2014 where persistent cloudiness and low temperatures caused relatively high September minimums (compared to top 3 years like 2007, 2011 and 2012, of course; they were well below the long-term average). 2016 still has many aspects going for it, like all that open water in the Beaufort Sea, low volume and snow cover that vanished at record speed. But it will take more to beat 2012, or 2007 and 2011 for that matter.

So, that's the question I will focus on in weeks to come: Can 2016 still make the top 3?

ASI 2016 update 2: closing the gap

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. 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 11th 2016

This update could have easily borne the same title as update 1: Both sides. Two weeks ago the ice pack was shrinking on both sides of the Arctic, causing sea ice extent to drop to unprecedented daily lows. In the meantime, weather patterns have switched and the ice pack is now expanding on both sides!

Of course, a dispersing ice pack will cause extent loss to slow down, or even stall completely for a while. Especially if extent was extremely low to begin with. And so that enormous gap between this year and 2012 is getting smaller every day, fast. 2012 had perfect weather for melting during the first two weeks of June, and there was a large amount of thin ice that kept extent artificially high.

More importantly, these weather conditions set the tone for the rest of the 2012 melting season, as a large amount of melt ponds preconditioned the ice for big melts during July and August. This is where 2016 is falling behind now, even though it has been and still is lowest in many respects (extent, volume, snow cover).

2012 is punching hard in this round. Will it be enough to knock 2016 out?

ASI 2016 update 1: both sides

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. 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 27th 2016

After an unprecedented warm winter and an unprecedented early opening of the Beaufort Sea, the 2016 melting season isn't showing any signs of shrugging off the 'unprecedented' label. What has struck me most so far, is that unprecedented things have been happening on both the Pacific and Atlantic side of the Arctic.

I've been closely observing events in the Arctic for almost a decade now, and have been writing about them since 2010, and during that time I have gotten used to this sort of see-saw, where fast melting on one side of the Arctic would be compensated by events unfolding slowly on the other side of the Arctic. But this year is different. This year the ice pack is under attack on both sides of the Arctic.

I have written separate blog posts to describe these events (see here and here), and in weeks to come these ASI updates will provide a comprehensive overview on what is happening to the sea ice in the Arctic, and how this melting season is unfolding.

Sea ice extent (SIE)

Let's jump right into it. Here's the latest JAXA SIE graph:That gap is pretty intense. I wasn't kidding when I said 'unprecedented'. Last year - orange line - was already quite spectacular, but this year is crazy.

As commenter Jim Pettit wrote on the Arctic Sea Ice Forum earlier today:

Grasping at uncorrected straws

I rather not give too much attention to fake skeptics, or climate risk deniers as I like to call them, but lately they are somehow finding it in themselves to come up with stuff that they think disproves Arctic sea ice loss. I've already posted about MASIE annual average nonsense (about which the last word hasn't been said), but in the past couple of days an even more spectacular and desperate attempt at downplaying Arctic sea ice loss has sprung up. I'm posting it as a reference, because I'm sure this will become a (short-lived) meme.

It all started with a blog post on fake skeptic blogger Paul Homewood's blog Not a Lot of People Know That (NALOPKT) about how the Danish Meteorological Institute (DMI) got rid of an old sea ice extent graph "simply because it gives the 'wrong' results". I decided to partake in the discussion because I knew what it was about and the reason the DMI removed that graph was because it had been replaced by another graph months ago, accompanied by the announcement that it at one point would be removed. The graph had clearly been neglected as it diverged more and more from other SIE graphs.

It was a nice exercise for me to drive my points home, but I had no interest in posting about it here, as it was a typical mountain-molehill type of misinformation, sprinkled with some suggestive conspiracy ideation, on the fringe of the fake skeptic echo chamber.

However, for some reason Anthony Watts elevated it to WUWT status:

The word 'inconvenient' you see there is spelled incorrectly and should read 'incorrect'. Let me explain in detail what this is about, and how pathetically these climate risk deniers are grasping at straws. It's all about these two DMI sea ice extent graphs, on the left the old SIE graph with a 30% threshold, and on the right the new one with a 15%threshold (as used by most organisations around the world):

Many months ago the old graph was replaced by the newer one. There was still a link to the old graph below the new graph, accompanied by a text saying it could continued to be be viewed "for a while" (see the image in this Great White Con blog post). It's quite clear from visual inspection alone that something was increasingly wrong with the old graph, and the logical explanation was that no one at DMI was correcting it because it had been replaced by the newer graph.

In fact, this was my first argument in the discussion on the NALOPKT blog, but this didn't convince the fake skeptics who rather believed that the DMI removed the plot because, and I quote (lest you think my imagination came up with it):

ASI 2015 update 7: to compact or not to compact

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.

September 1st 2015

Look at the sea ice concentration animation at the top right. Notice how the final frame suddenly is whiter than the preceding frame? That's a sign that we have entered the final phase of the melting season, when temperatures drop and melt ponds within the ice pack freeze over again. Sea ice concentration goes up, and the NSIDC SIC map becomes whiter.

But the Pacific side of the Arctic is still bluish. During the past two weeks the disintegration of that part of the ice pack has continued, spurred on by a late cyclone that further stressed the region (see special blog post on the matter) and increased the area that consists of a mix of ice floes and open water. The compaction potential of this region will probably decide where this melting season will end up on the various sea ice area and extent graphs.

And this end result still holds interest, because - somewhat surprisingly - the 2015 melting season could still achieve a top 3 minimum. Surprising, because the melting season started out with more volume, more multi-year ice, saw little and late preconditioning during May and June, and - despite a killer July - there has been relatively little transport and compaction this year.

With melting momentum mostly out of the picture now, it all comes down to compaction.

Sea ice area (SIA)

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

ASI 2015 update 6: one more high

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.

August 19th 2015

We are now entering the final weeks of the 2015 melting season. A relatively cold and cloudy start (not as cold and cloudy as the two previous rebound years) was compensated by a July that was ideal for melting. A continuous bombardment of heat and sunshine for weeks on end has caused some late melting momentum which is now keeping sea ice extent and area numbers dropping relatively evenly, despite a switch in weather conditions since the beginning of the month (see ASI 2015 update 5: late momentum).

As expected, the 2015 trend line on most graphs is hovering between top 3 years 2012, 2007 and 2011, and rebound years 2013 and 2014. It's difficult to tell how low things will end up. Melting momentum is one thing, but at this stage of the melting season weather conditions have the last word. It's compaction rather than melting that determines the final shape of the ice pack, and compaction depends on which way the winds are blowing, which in turn depend on the constellation of cyclones and anti-cyclones, or high pressure areas. See this blog post from an eternity ago, 2010, that explains how it works.

And now for the details...

Sea ice area (SIA)

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

ASI 2015 update 5: late momentum

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 30th 2015

My apologies for being a week late with this update. In my defence: things have been remarkably stable in the past three weeks, or all month really, both weather conditions and trend lines on graphs. To make up, here's a guest blog I've written, that was posted by John Abraham on the Guardian website today.

The article describes the melting season so far, starting out with more sea ice volume than previous years, because of the rebound in volume after the 2012 mega-record melting season. This year the ice pack underwent little preconditioning during May and June, perhaps slightly more than 2013 and 2014, but much less than big melt years such as 2007 and 2012.

This order of play led to the early conclusion that 2015 wouldn't break any records, and could very well end up near the previous two rebound years. However, subsequent weather conditions during all of July have broadened the range of possibilities (see the previous ASI update). I'll be going into the details in the July analysis that will be posted in 10 days or so, but I can tell you that July 2015 was exceptionally sunny and warm.

And that brings us to this melting season's main theme: Will the rebound remain intact, or will it be reversed, and perhaps even wiped out?

Let's first have a look at what has happened in these past 3 weeks.

Sea ice area (SIA)

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

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 3: what's it going to be?

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 21st 2015

Today is the day of summer solstice, when the Sun reaches its highest point as seen from the North Pole, beating down 24 hours per day on the sea ice below (when not blocked by clouds). The period preceding and following this event is very important for how the melting season plays out, as it is during this time that large parts of the Arctic sea ice pack are preconditioned through melt ponds.

This preconditioning in turn influences melting momentum. A lot of momentum almost guarantees high melt rates, whereas little momentum does the opposite, depending on weather conditions during July and August as well, of course. Last week I wrote a blog post in which I tried to assess the amount of melt ponding through May, by comparing this year to previous years.

The first half of May was extremely cold, with the second half of May showing almost the exact opposite. Still, indications were that relatively few melt ponds have shown up during May and the first half of June. This is now changing, as can be seen on the animation at the upper right hand corner of this blog post, where sea ice concentration is showing a very large blue patch of lower concentration on the Pacific side of the Arctic. That's because weather conditions conducive to melting shifted from the American side to the Siberian side of the Arctic, as was forecast two weeks ago.

Below an assessment of what's been happening in the past two weeks, and what is going to happen next week.

Sea ice area (SIA)

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

CT SIA recorded a huge 340K drop in one day. The last time a triple century break was recorded was in 2008. This brings the 2015 trend line right in the middle of the highest and lowest trend line in the 2006-2015 period.