« September 2011 sea ice volume, looking back and ahead | Main | NSIDC Arctic sea ice news September 2011 »


Feed You can follow this conversation by subscribing to the comment feed for this post.


Hi Neven,

Horribly off-topic here, but...

It seems that the North West Passage main channel is just starting to ice over. It hase been unambiguously ice-free, judged by the Cryosphere Today comparison maps since around about August 14. So that's about 50 days of entirely ice free navigation - a new record.

The Northern Sea Route opened up on about July 26 - so has now been open for about 70 days, and counting, which is also a new record. And, looking at the latest maps, it will probably stay well open for some time yet. I would not be surprised if it stays open for 3 months.

Jeffrey Davis

The odd thing about the decline is that follows last winter's mass of very cold air that permitted the development of the ozone hole in the Arctic.


Hi Jeffrey,

I may have got this wrong, but what I understood may have happened is that the Arctic troposphere was unusually warm last winter. This caused a bulge in the troposhere, which pushed the stratosphere further up, to a colder height. The damage was then done to the ozone in the stratosphere.

Bob Wallace

Warm troposphere, colder than usual stratosphere - consistent with what I've been reading.

Now, what will the effect of the ozone hole be (besides more skin cancer in Northern Europe and Canada)? Will it let heat escape thus slowing the summer melt and/or allowing more winter refreeze?


Sorry, Bob. No escape.

As idunno said, the reason for the ozone hole is that the troposphere bulged. It just got a bit bigger at that point.

A bit like using one of those nifty gizmos for stretching shoes. The shoe's still the same shoe, it's just marginally bigger where it matters. But pushing a shoe's profile outwards doesn't push any important atmospheric gases into colder regions to allow chemical reactions we don't want.

Yvan Dutil

Ozone is destroyed by chemical reaction ongoing on polar stratospheric cloud. They only form at very low temperature. When troposphere heats due to a reduction of the atmospheric transmittance (Say more CO2 and H2O) there is less heat going higher in the atmosphere. Off course, you can write your own radiation transfer code to be sure ;)

ThE SnYpEr AzZ

4000 km3 not 4 million.

Artful Dodger

Ironically, this is actually the Example at "The Psychology of Climate Change" website, Part 1 "Know Your Audience":

CRED researcher and director of the Yale Project on Climate Change Anthony Leiserowitz finds that people often confuse the hole in the ozone layer with climate change.7 This is happening, in part and ironically, due to a science communication victory. Scientists and the media effectively and extensively covered the threat posed by the growing ozone hole, eventually resulting in international political action to phase out the main contributor, chlorofluorocarbons or CFCs.

But now many people conflate their mental model of the ozone layer with how the atmosphere works, in particular with how greenhouse gases accumulate in the atmosphere. Dr. Leiserowitz has found it leads to some interesting misconceptions that require updating, such as: If there is a “hole” in the ozone layer, and there is a global “greenhouse” effect, then there must be a “hole” in the “greenhouse.” Some Americans thus reason that this “hole” either allows more solar radiation into the biosphere—warming the planet—or, alternatively, allows heat to escape—cooling the planet.

Although logical, such reasoning has unfortunately led to construction of an inaccurate mental model about the causes of climate change that, in turn, causes many Americans to support inappropriate solutions, such as believing that the best way to solve global warming is to ban aerosol spray cans.8 Climate change communicators should try to identify this commonly mistaken mental model and replace it with correct information.


4000 km3 not 4 million.

How embarrassing! Thanks, ThE SnYpEr AzZ.

Nightvid Cole

Just a few more days to see if the Northern Sea Route will make it to October 10 before closing (based on IJIS map) and set a new record...

The comments to this entry are closed.