Sunday, 1 May 2016

Beaufort Cryosat February

Beaufort has already started to collapse, I will have more about that in a post to follow when I have the time tomorrow. For now, I have amended images from Meereisportal for a close look at Cryosat 2 ice thickness in Beaufort.

More commentary about the recent Cryosat 2 data is available from Neven at the Arctic Sea Ice Blog.










This ties in with PIOMAS grid box effective thickness which as of this February (and March as well) was the lowest on record. February being 1.5m thick.


Whilst the Siberian coast remains more normal, and the current collapse of Beaufort may stall as it hits the export of multi year ice into Beaufort, prospects for a very low minimum, possibly beating 2012 look good. So we may be in for an exciting year in the Arctic Ocean. Fingers crossed for a classic melt season.

8 comments:

David Rennie said...

Sea Surface Temperatured globaly, and across the Arctic have been one full std dev above the previous record in the ESRL-NOAA data set for Jan - Mar. Where the previous record was 2 std deviations this year they have been three std devs.

http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl

The Arctic is showing the impact of this with PIOMAS figures for April expected to be at record low levels. Combine that with record temperatures and the outlook for the ice is far from sunny.

Dreessen said...

Chris,
What would you say the percentage chances of a record minimum are?

Chris Reynolds said...

Dreessen, David,

I am becoming much more optimistic about the prospects for a really exciting year in the Arctic Ocean.

Beaufort may prove critical. ASCAT shows some export over winter, so the crash I'll be discussing in my next post may well stall (a bit). Given ice state in Beaufort there is a reasonable expectation (IMO) of large tracts of open water early in the melt season under high insolation. From previous work for the whole Arctic, current ice thickness in Beaufort (~1.6m now) is well within the range of seasonal thinning - i.e. near 100% open water formation efficiency.

Under the Arctic Dipole (AD) regime of post 2007 summers the June/July average pressure shows a strong Beaufort High. This should drive water warmed in early season open ocean in Beaufort towards Chukchi and under the main pack. What goes towards Chukchi may then be entrained under the AD and driven into the East Siberian Sea. Ekman pumping may be expected to drive net flow to the right of the wind direction through the entire ocean column, but surface warming will be more in line with the wind flow.

The end result being that early inroads into the very thin poor ice state in Beaufort may then assist melt in the thicker (more normal) ice state in the East Siberian and Chukchi seas. That is before we get to considering the import of Pacific water through Bering due to the AD. The ENSO warmed tail from the tropics along the US/Canada East Coast may be entailed into Bering flow.

I think that if I stick to stats for the whole period 1978 to 2015 my SIPN prediction in early May is likely to overshoot. I am seriously considering changing my method to use 2007 to 2015 data (this made the method fail in 2014). I may however stick to the previous method and note the likelihood of a low end fail when the prediction is made.

In 2012 nothing at the start of the season justified the outcome. I haven't seen a year more primed to large losses than this year (noting that I have not carried out a forensic study of all years since 1979).

Kevin O'Neill said...

Chris - I've been expecting an exciting 2016 melt season since last fall. The patterns I saw in annual data seemed to inevitably lead to a warm arctic winter and relatively small winter volume gains. But even I have been surprised by the magnitude of the warmth. DMI N80 has been so far from baseline and historical values this winter that I have no idea what it means. There's simply nothing to compare it with.

It's hard to believe the melt season is just beginning - there's been more excitement the last month than some entire summers past :)

I'm expecting not just a record year for extent and volume, but significantly lower values than we've ever seen. Given the other climate news in the headlines it may already be too late for a wake-up call, but maybe - just maybe - a completely insane number can finally drive a stake through the heart of the multitude of denier memes and force politicians to realize we need a global war on climate change. Otherwise we're gonna lose a war many didn't know we were even fighting.

ATTP's recent post (Maybe We Really Are Screwed is what I've been thinking for a few years now.

Chris Reynolds said...

Hi Kevin,

I don't think anything but time will kill the denier crap. I get the impression that a lot of deniers see climate change denial as a badge of intelligence, of course it means either they're stupid or suckers. I remain the only person I know who has given up car ownership as a result of the evidence.

What bothers me is that the most reasonable explanation for the extremely weird conditions over this winter is the El Nino. Yet this winter has been so extremely weird that precedence does not support that simple explanation. If 1998 was a super El Nino, in terms of its wider impacts, this seems to be a hyper-El Nino.

Dreessen said...

Chris,
so would you say 50-50 for a record low?

Chris Reynolds said...

Dreesen,

I wouldn't go as high as 50/50.

I'd say beating 2012 still looks a long shot at this stage, it'll take very good melt weather, 2012 was damn near perfect. The bottom line is that nobody knows what the impact of this winter's freakish weather will have on the chances for a strong and persistent Arctic Dipole pattern. A continuation of the winter weirdness into the summer may enhance the likelihood of an Arctic Dipole, or it may impeded the formation. If it impedes it we get a re-run of 2014 with a net volume gain on last year.

Dreessen said...

Thanks Chris.
Kevin, I don't know if I'd go as far to say that we're screwed. There has been some good news with the greening study which does provide a little bit of a cooling effect (I've heard .3C) and that forests won't lose as much carbon as previously thought.