Sunday 31 July 2011

An Observer's Prediction.

Over at Neven's Sea-Ice Blog there's an interesting post by Russell McKane predicting September sea-ice extent using a site and technique I've never seen before. It's as well to read that post before proceeding here.

Monday 25 July 2011

Arctic sea-ice free this decade?

As I outlined in my post In Flux, a key finding concerning the Arctic has made me wonder about whether we are indeed on a fast-track to a seasonally sea-ice free Arctic this decade. However on reflection that is in part an emotional reaction to an observation that unsettles me. I had been going to wait until September to post on this subject, so I could see what happens this year: I still see 2011 as having the makings of a spectacular season. But in the light of Maslanik's latest paper, and of the points raised by two commenters on the 'In Flux'page, I thought it might be as well to state in detail why, on balance, I don't think we are on a fast-track, and why I think key observations are being misinterpreted.

Update - I have since changed my view on this as outlined in this post.

Saturday 23 July 2011

Maslanik, Arctic sea ice change in Spring 2011.

Neven has recently posted a good summary article about what I consider a very important recent paper from Dr James Maslanik and co-authors. If you've not read it, or the original paper, I suggest you read his post before my comments.

Maslanik et al find an increasing trend in multi-year (MY) sea ice through the 1980s and a loss through the early 1990s, these are associated with different phases of the Arctic Oscillation (AO). During the period of gain from 1996 to 2001 the sea level pressure showed a weak positive Arctic Dipole Anomaly (AD) (high pressure over Canada, low over Siberia), then the losses of 2002 to 2011 were associated with a negative index AD. This could be taken to imply that the main process at play in the loss of Arctic sea ice is due to changes in wind patterns, a common denialist meme. However that is not the case, as I will explain.

Sunday 17 July 2011

In flux.

I've been a sceptic of the idea that the Arctic will have a virtually sea-ice free minimum this decade, I've said elsewhere that I think it will happen next decade at the earliest. Now I find myself questioning my position.

The loss of multi-year sea ice Part 2.

In the previous post I looked at what had been happening to the extent of Multi Year (MY) sea-ice and the nature of it's presence in the Arctic sea-ice. There is more research however that pertains to changes in it's thickness, and the thickness of the Arctic sea ice in general.

Down came the rain.

Pretty good weather last week, then come Friday, leaving work...

It's rained Saturday and Sunday as well.


Hat tip to the Late Great John Peel for this one.

Thursday 14 July 2011

The loss of multi-year sea ice, Part 1.

There are two types of sea-ice in the Arctic, first-year (FY) and multi-year (MY). It's been known for some time that MY sea ice is in decline.

Here is an NSIDC graphic of the series of James Maslanik.