Arctic Northwest Passage ice anomaly about to make a big play? Northern Sea Route opened very early. Arctic Alaska opened 2 weeks early - WILL THE NORTH AMERICA HEAT WAVE OPEN NW PASSAGE ICE EARLY OR ALLOW IT TO STAY OPEN LATE?

MY PERSONAL OBSERVATIONS INDICATE THERE COULD BE A LATE MELT SEASON MOMENTUM OCCURRING THROUGH SEPTEMBER RESULTING IN MORE NORTHWEST PASSAGE ROUTES REMAINING OPEN LATER THAN AT ANY TIME IN THE PAST SIX YEARS I'VE BEEN OBSERVING THE ARCTIC. NEVEN SAYS THERE COULD BE AN ANOMALY IN THE MAKING... WHAT DOES THIS MEAN FOR NW PASSAGE YACHTS?

CHECK BACK FOR UPDATES.

- - - BLOG SNIP: http://neven1.typepad.com/blog/2015/07/asi-2015-update-5-late-momentum.html#more - - -

by Neven Acropolis

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 Todaysea 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 blogI'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:

Despite almost perfect weather conditions this moth so far the 2015 trend line hasn't fallen off a cliff, but that's only logical, given the lack of preconditioning during June. What's remarkable, though, is how those stable weather conditions have been accompanied by an almost monotonous decrease that is now slowly tapering off, but well below 2013 and 2014, and not too far from the top 3 years.

Sea ice extent (SIE)

The same steady decrease can be seen on the SIE graph (based on data reported by the Japanese Arctic Data archive System):

The 2015 trend line has come a long way from being almost highest after the first week of the month, but is now also slowing down and still close to 2013.

Cryosphere Today area per IJIS extent (CAPIE)

With area dropping relatively fast, and extent less fast, compactness will also drop fast. In these updates I refer to compactness as CAPIE, meaning Cryosphere Today area divided by IJIS extent numbers, a measure that wasinvented collectively back in 2010, when the Arctic Sea Ice blog first got underway (read the CAPIE segment in ASI 2014 update 2 for a thorough explanation of what CAPIE actually is and what it tells us).

Here's the current situation:

The 2015 trend line has continued the precipitous drop that started towards the end of the June, and is now among the lowest on record. This, of course, has to do with 1) dispersal of the pack's ice floes, especially on the American side of the Arctic, and 2) massive melt ponding. July has made up for the lack of momentum being built up during June. We now have to wait whether this late momentum can still influence this melting season's final outcome, and if so, by how much. I eagerly await more data on melt ponds and volume.

Regional SIE and SIA

For the past few weeks I've been mainly focussing on the thicker multi-year ice in the Canadian Archipelago, Beaufort and Chukchi Seas, but in the past few weeks the melting season has been making lots of headway on the Siberian side of the Arctic as well. The Northern Sea Route has opened really early this year, as shown by yet another excellent video made by Jim Hunt from the Great White Con blog:

Most of the action has been taking place in the East Siberian Sea, where the ice is disappearing even faster than in 2012:

Wipneus has sent me another custom-made regional map that shows the changes that took place in this region during the past two weeks (red = less ice than two weeks ago, blue = more ice than two weeks ago):

That's a lot of red!

At the same time Baffin and Hudson Bay still refuse to melt out, meaning there is still almost 400K of ice that hasn't shown up yet on the graphs:

But, of course, there still has been plenty of melting in the past two weeks:

Weather conditions

With all that talk about those perfect melting conditions the past couple of weeks, it's high time we look at what the weather has done and will do, starting, as always, with sea level pressure (SLP) as displayed in this three-week animation of Danish Meteorological Institute SLP images:

I have not often seen this combination of big size and persistent stability in a high pressure area during summer (remember how I said it would be HUGE in the last ASI update?). The only things missing to make these weather conditions truly perfect, are compaction and transport. For that you need some lower pressure on the Siberian side of the Arctic, creating the winds that get everything on the move.

But still, an area from Greenland all the way to Alaska has been bombarded with sunshine the past three weeks, with the Canadian Arctic Archipelago at the very heart of it. No wonder the fast ice in the Northwest Passage's main channel has completely shattered in the past week:

Towards the end of the DMI SLP animation the high pressure is seen to be moving towards Siberia with a cyclone emerging over the Beaufort Sea, and so it's interesting to see what's going to happen in the coming 6 days, according to the ECMWF model (click for a larger version, and go to the ASIG Forecasts page for daily forecasts):

Wow, this is interesting, and I'm not sure what to make of it really. The cyclone is going to remain weak and remain in place, surrounded by high pressure from all sides, with two intense epicentres near the Atlantic-Siberian side of the Arctic and Greenland. The ice in that part of the Central Arctic Basin, and the adjacent ice left in the Laptev and Kara Seas - which should be relatively thin by now, as it didn't really get thick there over winter - is going to get tanned in the coming week.

At the same time that cloudy cyclone is offering some shade to the thicker multi-year ice in the Beaufort Sea that has been under siege by the Sun for a large part of this melting season, but the risk is that those dispersed floes get pushed into warmer water by the winds the cyclone will produce. I'm expecting a continuation of the slowdown that appeared on the SIE and SIA chart in the past few days, but things will probably not completely stall like we saw the last two years.

This also depends on temperatures, of course. The DMI 80N temperature graph shows that the trend line has been hovering around (and even above at times) the average and has only been going down since a week or so:

This is also corroborated by this NOAA/ESRL Physical Sciences Division map showing how warm much of the Central Arctic and especially the Canadian Arctic Archipelago has been from July 7th to 27th:

What can we expect for the coming 7 days? This is what the GFS temperature anomaly forecast maps provided by the excellent Climate Reanalyzer website are showing:

A couple of days of anomalous warmth for the ice off the coast of West Siberia, and a relentless heat wave continuing over the Canadian Arctic Archipelago. I don't see how the Northwest Passage can withstand so much heat and sunshine, and so it looks like yet again both passages will be open this year.

Unless sea surface temperatures are really cool, which they aren't:

Things continue to heat up everywhere, although I expected much more heat on the Pacific side of the Arctic, given the situation two weeks ago when SST anomaly was off the scale in that part of the Arctic. Still, it's comparable to the situation on July 28th 2012, August 4th 2014 (ie one week from now), and much, much warmer than July 26th 2014:

Conclusion

A warm and sunny July is making up for the lack of preconditioning during June, which means that it isn't likely that 2015 will end up as another rebound year. But if this year is proving anything, it's that you can't have a record without serious preconditioning of the ice pack during May and June, and subsequent melting momentum that keeps working at the ice until it can no longer hold out in August and September.

Perhaps 2015 can still make the top 3, but it will require a continuation of weather conditions that are conducive to melting, compaction and transport all the way to the minimum. Either way, the rebound (or 'recovery', as some called it prematurely) is in danger of getting wiped out, which brings us back to square -10, meaning that Arctic sea ice loss is still progressing much too fast.

We now await the latest PIOMAS update to see what has been happening volume-wise and whether the Arctic sea ice pack returns to the post-2010 position from where it could go really low, perhaps all the way to essentially ice-free conditions. All it takes is the preconditioning of 2010 or 2012, followed by a July like the one that is almost behind us, and then 2007-style compaction and transport through Fram Strait. I'm really convinced of that. The question is not if, but when.

Enjoy the Arctic sea ice, it's the only Arctic sea ice you've got.