Arctic Sea Ice

PIOMAS October 2015

I'm a bit late with this, as the latest data (up to September 30th) was released last week. To make up, here's Andy Lee Robinson's latest video showing the PIOMAS sea ice volume minimum long-term trend:

 

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Here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

Sea ice volume stays relatively stable during September, with some years going up a bit, others still going down a bit. 2015 had a very small uptick of just 57 km3, similar to 2012's increase of 35 km3, so no changes there, this year still has 2000 km3 more ice than the 2012 record smasher. But with 2013 going up by 169 km3, the gap has become so small (289 km3) that this year is almost on a par with the first rebound year. And it's still 1087 km3 below last year's further rebound.

These differences are more visible on Wipneus' PIOMAS volume graph:

With 2015 ending as 5th on record, the trend hasn't gone back to the drastic decline of the 2007-2012 period, but neither has it confirmed any suspicions of recovery. It is simply continuing the downward linear trend, as can be seen on the PIOMAS sea ice volume anomaly graph:

Arctic sea ice -- in pre-election perceptions

As longtime ASIB readers may know, my colleagues and I have been tracking US public perceptions of Arctic change. This started with analysis of questions written by others for the nationwide General Social Survey in 2006 and 2010, then shifted to our own questions placed on another nationwide survey in 2011, and a continuing series of statewide New Hampshire surveys since then. Results have been highlighted in several posts here by Neven (June 2015, August 2013, April 2013) that refer to some of the underlying research articles. Our most recent article, “Polar facts in the age of polarization,” in Polar Geography, is a good source for question wording, analysis and citations to earlier work (write if you want a copy). Figure 1 below updates one of the graphs from that paper, adding data through September 2015.

Figure 1

Our sea ice question reads as follows:

Which of the following three statements do you think is more accurate?  
Over the past few years, the ice on the Arctic Ocean in late summer ...
    Covers less area than it did 30 years ago.
    Declined but then recovered to about the same area it had 30 years ago.
    Covers more area than it did 30 years ago.
    don’t know/no answer

The top line in Figure 1 tracks the percentage of “less area” responses on surveys from June 2011 to September 2015. A red triangle at far left shows the corresponding percentage from a nationwide survey in 2011, which came in quite close to New Hampshire.

2015 minimum overview, part 2

This is a continuation of Part 1, wherein I posted several graphs and maps depicting the 2015 minimum, and the weather conditions leading up to it (Tamino has a great blog post showing the long-term sea ice extent trends, all of them, not just the cherry-picked, meaningless one the GWPF selected to mislead).

Before jumping into the ice age and volume data that is (perhaps) most interesting, intriguing, but also incomplete, I want to refer to one more factor that - besides weather conditions and ocean heat flux - can play an important role in how a single melting season plays out: land snow cover.

Here are the monthly Northern Hemisphere snow cover anomaly graphs from the Rutger University Global Snow Lab during the melting season:

It's clear snow cover got pretty low during June and July. It's a bit of a chicken-or-the-egg kind of mutual influence thing, with an albedo feedback leading to warming over land, leading to increased snow melt, etc. which then starts to influence the Arctic and its sea ice as well. There's been ongoing speculation on this correlation between land snow cover and sea ice for years now, and my guess is that there's a there there, but as it isn't the only influence, it's hard to quantify it. Either way, it has to do with (global) warming, as attested by commenter Al Rodger's guest blog a few years ago: The untold drama of Northern snow cover.

And so we turn to multi-year ice. I'll repost this animation from a blog post I posted two weeks ago, showing how virtually all of the older, thicker multi-year ice on the Pacific side of the Arctic has melted out this melting season: