Mad max?

Okay, I'm not calling the max - short for maximum extent of the sea ice pack that marks the end of the freezing season - as I've sworn not to do that anymore since 2012, when I called the max twice, only to see the trend line bounce up higher and later. But this year something really interesting is taking place.

It started almost a month ago, on February 15th to be exact. IARC-JAXA (IJIS) sea ice extent grew to 13,942,060 square kilometres, and the 2015 trend line was just below the middle of the pack. Nothing out of the ordinary. In the two days that followed extent went down by over 170 thousand km2. Still nothing out of the ordinary.

But the gains in the following 8 days, up to February 25th, didn't manage to make up for the deficit and the preliminary peak was still standing. Then a drop of over 240 thousand km2 followed, somewhat out of the ordinary, and that's where we are as of today.

I've made a graph showing what has happened since February 1st:

Last year, extent trended relatively low as well, but a surge in the middle of March made for a late max on March 19th. The current trend line is much lower, but there is enough refreezing potential on the fringes of the ice pack, as this sea ice concentration map from JAXA shows: 

This map, by the way, was taken from the Arctic Data archive System (or ADS) that has temporarily replaced the IARC-JAXA (IJIS) website which always provided us with graphs and the sea ice extent numbers based on the AMSR-2 satellite sensor. I overlayed the image with the 2000's average (orange line). As can be seen there's still plenty of room for ice growth in the Bering and Okhotsk Sea, some in the Barentsz Sea as well. At the same time, some of the growth could be offset by melting/compaction in the Baffin and Labrador Sea, as they look pretty filled up.

All depends, as always on the weather. If we say that last year's max date is the latest possible date, there's still two weeks to go. That's a relatively long way out, given the potential swings during this transition phase between freezing and melting seasons, but we can at least look at the forecast for the coming week.

Here's the atmospheric situation for the next six days, as forecast by the ECMWF weather forecast model (click for a larger version):

Okay, so first of all, there's a huge storm approaching the Atlantic side of the Arctic. It might be difficult to see because of all the colours and many isobars, but it's possible to make out the features of Scandinavia, East Siberia and Alaska.

Quite a few storms have been funnelled into the Arctic via this route this winter, but this is a really big one, potentially bombing out at 950 hPa. It's difficult to tell what its influence will be on extent numbers at this final stage of the freezing season. The storm will be relatively short-lived, will probably cause some compaction in the Barentsz Sea, possibly compensated by increased transport into the Greenland Sea, via Fram Strait.

Another factor is the heat and moisture that this storm will inject into the Arctic, and so we turn to the temperature anomaly forecast on the ClimateReanalyzer website (from the Climate Change Institute at the University of Maine):

That's a lot of (relative) heat reaching the Atlantic side of the Arctic, which should prevent any serious refreezing there in the coming week. At the same time very low temps are moving over the Bering Sea area, so possibly a lot of new, very thin ice is formed, especially as some very strong northerlies are forecast for the region. This could very well cause a second peak that tops the one reached last month, like happened more often in recent years. If not, this will be the lowest maximum in the IJIS SIE record, and the first not to pass the 14 million km2 mark. In other words: a mad max. ;-)

Although this event adds extra spice to the end of the freezing season, in itself it doesn't necessarily mean anything with regards to the coming melting season. Sure, 1 million km2 less ice than around this time in 2012, means a head start with regards to how much insolation the fringes of the ice pack get to build up, but if those cyclones keep getting pumped towards the Arctic, increased cloudiness will quickly negate this advantage, especially during that important start of the melting season when the amount of melt ponds on the ice pack greatly influences the chance for new records at the end of the melting season.

First, let's see what this big storm does to the numbers in the coming week, and whether cold northerlies on the Pacific side of the Arctic have it in them to yet again emphasize the futility of trying to call the maximum. If you can't wait for me to call the maximum, you can follow the daily nitty-gritty over on the Arctic Sea Ice Forum.

Comments

[wayne]

interesting discussion about albedo, however sea ice absorbs sunlight @75 North altitude when the sun is 3 degrees above the horizon. Perhaps the models need some tweaking.

[wayne]

75 degrees north latitude of course

[Bill Fothergill]

On albedo and incidence angles...

Those interested in the subject might care to look at this article from the Journal of Geophysical Research...
http://onlinelibrary.wiley.com/doi/10.1029/2009JF001444/pdf

In particular, have a decko at Fig 9b on page 8 (of 15).

A little care is required over the terminology. When I was doing light physics at school, and in 1st year Uni -it might have been during the Cretaceous, or possibly earlier - angles were always taken relative to a line at right angles to the plane of interest. (Otherwise known as the normal.)

However, when dealing with the sun, there can be confusion. The Solar Zenith Angle is indeed measured from the normal, but the Solar Elevation Angle is, as the name suggests, the angle measured from the horizon.

When the sun is low in the sky - low Elevation Angle, high Zenith Angle - it can indeed glint in a dazzling fashion off water, or ice, or tarmac. Similarly, if one is flying over the Pacific near the equator at lunchtime, one can also see a great dazzling orb reflected off the water.

One of the things people forget when talking about low sun glinting off, say, water, is that there is also a direct path from the sun to the back of one's eyeball.

The suggestion that this kind of stuff is unknown to scientists is simply embarrassing.

[iceman]

@Neven "Plenty of snap potential, but first all of this 'heat' (it's temperature anomaly, so still plenty cold, just not megacold) needs to get out of the way, and by the time it does, it'll probably be too late for a snap:"

This will be entertaining to watch. A week from now the extent gains in Barentsz and Baffin/Newfoundland will be trailing off or reversing. Looks like not much contribution from Okhotsk by then. Meanwhile an extent drop in Kara from melting and compaction. Will Kara refreeze before the newly-formed thin ice melts elsewhere?

[iceman]

edit: gains in Bering not Barentsz

[VaughnA]

The suggestion that this kind of stuff is unknown to scientists is simply embarrassing."

Bill, spot on.

I am also waiting for Cincinnatus to publish a longer list than I of valid and reliable studies that provide good evidence that climate change is a matter of natural variation and that human activities have nothing to do with it.....haven't seen a longer list than mine from anyone in fact. (See my post in "Thinner and Thinner" about my list.)

[Neven]

A larger jump today of 48K is reported by JAXA. The snap has begun. 246K left to go.

[Bill Fothergill]

@ Nev

Yep, we are seeing some synchronised swimming from JAXA and NSIDC. As you and many others know, JAXA reports on a 2-day average basis, so their recent massive rebounds match well with the 111k sq km rise in the NSIDC daily numbers seen over the last 3 days.

By the time NSIDC posts the data for 13th March, we will start to see if their 5-day Charctic figures are showing any significant upward motion.

cheers bill f

[Neven]

The forecast has changed again, with cold and northerlies all around now! I'm not so sure any longer that the preliminary max from Feb 15th is safe. Things could get tight.

[iceman]

Interesting that this year will have either the earliest extent maximum or (perhaps) the latest. It's an extreme instance of a sinusoidal characteristic that OSweetMrMath pointed out on ASIF: the function is flattish near its maximum, which makes the timing hard to predict.

[wayne]

these latest are sea ice shoreline gains, not quite unexpected, the SST's where there is the greatest potential extent advances are simply too warm. Baffin Bay is the one to watch because it was quite cold over the winter and I suspect a lag in its descent in extent. The Cold Temperature North Pole is weakening over Hudson Strait and a new one is showing over Alaska, this changes the configuration of the Jet stream substantially. The huge Atlantic Arctic vortex heat engine is finally fading. Check out the very warm temperatures much throughout Midwestern North America, the cold air is vanishing fast in the South.

[Neven]

The increase has come to a (temporary) halt, as JAXA reports a small drop of 9498 km2. So that's another day gone by and 256K left to go.

Man, this is so exciting. ;-)

[Al Rodger]

I reckon that unless there is some big big reason to think otherwise, two more days of SIE faffing about with no sign of a rise and I would call 15th Feb as the maximum. JAXA gives the latest SIE (13th March) as more than 250,000 sq km below 15th Feb and there are no years on the JAXA record that have gained/regained that amount of SIE from this date on. All bar 2003 managed less than 150,000 and by 15th March 2003, the gain/regain was below 200,000 and dropping by the day.
In fact, I would give it just one day and call it tomorrow.
(Of course the last time I made a sea ice announcement, the big trend stalled the very next day.)

[Neven]

Hi Al, good to read you.

JAXA gives the latest SIE (13th March) as more than 250,000 sq km below 15th Feb and there are no years on the JAXA record that have gained/regained that amount of SIE from this date on. All bar 2003 managed less than 150,000 and by 15th March 2003, the gain/regain was below 200,000 and dropping by the day.

Yes, but on the other hand, no years on the JAXA record have been as low as now, meaning there's a lot more re-freezing potential.

I've seen some things in the forecast for Wednesday and Thursday that I'd like to see play out before calling the max. Which of course I won't do. ;-)

[Neven]

Another 24 hours gone, and yet again JAXA reports a minimal drop of 129 km2.

It will now take a real shocker to startle the crows. :-)

[Al Rodger]

Well, I threatened to do it so I shall. The comment that there is less ice so more open sea in line of fire (or frost) is greater which could allow a bigger rise - that is true. But it hasn't been evident within the JAXA numbers. 2003 is the biggest post-13th March rise in JAXA but there was over a million sq km more ice back then.
I did a quick check at the NSIDC ch Arctic page and, guess what, over the same period the biggest post-13th March increase there was actually just last year, 2014, when 225,000 sq km was added. But to top the NSIDC February figure, 2015 would need 230,000 sq km.
So, bravely, I say we have seen the maximum Arctic daily SIE for 2015 back in February.

It is a safer bet to say that 2015 will see a record daily low. JAXA is presently 440,000 sq km below that daily record and NSIDC 380,000.

All that said, the headline figure is always the highest monthly NSIDC average and it looks pertty certain that will be the February figure of 14.41M sq km, the previous record being 14.43M sq km in March 2006. For March 2015 to exceed the Feb 2015 average, the average for the rest of March would have to be 14.50M sq km to the end of the month, that is 200,000 sq km above the latest figure, from tomorrow and right to March 31st. I don't see that happening.

[Bill Fothergill]

Since about the 8th of March, I've thought that the NSIDC monthly record low for March (2006) could possibly be under threat.

As AL has indicated above, that is now starting to look like a distinct probability. The NSIDC daily for the 13th has been revised downward, and the value shown for the 14th isn't doing much to bump the average upwards. All 5 daily values constituting the rolling 5 day figure on Charctic are now within 33k sq kms of each other, so there are no "cheap" gains to be made over the next few days.

The Charctic value for the 14th stands at 14.321 million sq kms, a value that 2006 effectively reached on the 24th. Unless something significant happens very, very soon, 2015 will definitely end up with the lowest NSIDC March average seen thus far.

Not only that, unless there is some significant upward movement, 2015 is also going to start April with a pretty low extent.

[wayne]

take it this way, this years max is old news before it becomes news.
But it is good to wait for an official pronouncement.

The best thing to do while we wait is to differentiate 2013-14 with 2014-15. After all last year's ice was about the same extent when it went the other way. There is likely less sea ice thickness than March 2014. Does it make sense that less sea ice extent is coupled with greater average thickness?

[Kevin O'Neill]

Wayne - "Does it make sense that less sea ice extent is coupled with greater average thickness?"

Intuitively, no. But there are confounding factors - especially transport. Which year saw more and older ice pushed out the Fram and Nares?

[wayne]

Kevin, I would tend to believe less movement during the summer of 2013. But more loss of sea ice in the North Atlantic sector during the same period. But 2014 summer melt had greater open water in Arctic ocean Gyre area , the traditional place where pack ice is thickest.

[Jim Hunt]

Kevin/Wayne,

I currently find myself taking issues of export and the like from the PIOMAS thread on here over to the forum:

http://forum.arctic-sea-ice.net/index.php/topic,1149.msg47797.html#msg47797

[Al Rodger]

So having heard me call the minimum as that back in February, the Jaxa SIE stops its faffing about and puts on 69k over two days. Still 186k to go before my bravery turns into foolhardiness.

I might have been less brave given a bit of anslysis I was prompted to do by an enquiry elsewhere. The later timing of the SIE maximum can be made to look a bit illusory, lots of noise on an underlying trend that can appear very small.
For instance, the NSIDC climatology maximum for 1981-2010 gives a timing very close to the average JAXA timing for 2003-2014.
But it occurred to me that the NSIDC monthly data allows a comparison of the average ice in February and the average ice in March all the way back to 1979. And that shows quite a strong trend, but only since the mid 1990s = 24k/yr +/-10k (2sd). When I have a few moments, I double-check that result and try to convert it into a shift of timing in the maximum.
What does stand out is that average Feb SIE had not exceeded average March SIE since the mid 1990s. But that looks mighty likely this year.

[Philip]

the Cryosphere today SIA has not changed much for about a week. Getting less and less likely that there will be a big freeze.

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

from day 65 13,008040 to day 73 13,001980.

[Neven]

the Jaxa SIE stops its faffing about and puts on 69k over two days.

Indeed, and the forecast is for more cold and northerlies in the Bering AND the Barentsz. I'm going to try and write an update later today.

[Werther]

The excitement over the yearly max is just a detail within the bigger story. I've come to see 'winter power' as important.
These small samples of NCEP/NCAR show -4-+4 dC temp anomaly on 1000Mb. Period 1/10 to 15/03, winters 12-13, 13-14, 14-15.

Make your own judgement. I'll get back to this later, but look at the difference in the Barentsz-Kara and Baffin regions.