Weatherdem's Weblog

Bridging climate science, citizens, and policy

State of the Arctic – 12/23/2008

6 Comments

The Arctic is exhibiting characteristics indicative of the well-documented long-term warming trend over the past 100 years.  After reaching the second lowest areal extent back in September, the Arctic ice sheet underwent a rapid re-forming process.  With no sunlight and sub-freezing temperatures, that was to be expected.  But that’s not the whole story.  In the past two years, atmospheric conditions have shifted from long-term states to a new state that has allowed more warm air and water to encroach above the Arctic Circle (I’ll write a more extensive post on this another time).  That anomalously warm water has released a lot of energy back into the atmosphere, adding to the latent heat released by freezing water.  The result?  Arctic sea ice formation has temporarily stalled, as seen in the following time series:

Currently, temperatures in the Arctic north of Canada are 6C warmer than the climatological average.  That large anomaly is indicative of just how much heat was transported to the pole this year.  As you can see from the graph, areal ice extent in 2008 is now lower than it was at the same time in 2007.  It is also well below the climatological norm.  Here is how the ice extent looks to satellites:

This picture shows another reason why the rapid growth of new ice has stalled: there is much less space to expand to than there was in October.  The area between Greenland and Scandinavia and Greenland and Canada will of course see additional ice growth.  The ice will also grow into the Pacific south of Alaska and Russia.  But those regions contain less area than the area that saw refreezing in October.

With the passing of the Winter Solstice, the sun will begin shining over more area in the Northern Hemisphere every day again through June.  The Arctic ice sheet will likely grow through March before remelting again next year.  What will the maximum extent of ice in 2008-09 be?  The long-term health of ice sheets and glaciers is not good in the face of multi-degree positive temperature anomalies.

***

billlaurelMD posted a similar diary at a later date – the graph in his diary demonstrates that the phenonema described above have continued.

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6 thoughts on “State of the Arctic – 12/23/2008

  1. WeatherDem, Your Arctic Ice graph appears to show an overall growth trend. This supports measurements showing Arctic ice formation is 10-30% above this time last year. Antararctic ice has been demonstrably thickening as well.

    Plus the fact that paleoclimatic records show that the Arctic has been ice free in the past demonstrates that natural factors are responsible for ice formation and melting.

    If you are interested in open debate on this topic, check out a recent body of scientific evidence by Henrik Svensmark that makes sense with ALL the major aspects of our climatic history. You can read on the internet on his work about the interplay of the sun and cosmic rays and its global effect on cloud cover and therefore, global temperature change. He also has a book out with Nigel Calder called “The Chilling Stars”

  2. The time series graph is only valid for the time period Sep 2008 to yesterday. There are additional time series at the University of Illinois website that look at the areal extent for many years. They show maximum extent and minimum extent have both decreased (slightly) with time. Ice will continue to form in the Arctic for the forseeable future. One big question is how soon will the Arctic be ice free in the Northern Hemispheric summer? I’d say that it will occur a lot sooner than many recent, official projections offer. The big topic I didn’t cover in this post is the lack of ice volume, which reached a record low this year. More ice in the Arctic this summer was one year old or less than last year. That young ice melts more easily than the older ice sheets whose volume has been greatly reduced.
    Ice on the Antarctic continent has been slowly increasing. However, ice on the Antarctic peninsula has been thinning and breaking off – once again at rates faster than recent, official projections. The state of understanding of polar weather and climatological processes are not well understood. Those processes need to be accounted for in coupled atmospheric-ocean models so their effect on the remainder of the climate system can be assessed.
    The Arctic and Antarctic have indeed been ice free in the geologic past. What of the remainder of the globe? Sea levels were 73m higher and deserts covered most continental land masses. That kind of climate would be unlike anything that many plants and animals are used to.
    Anthropogenic factors have been the predominant factors on our climate system for some time now. There is no debate about that. The only debate left is what to do about it.

  3. A couple of comments on your reply:
    1. I was not advocating that we will have an ice-free Arctic anytime soon, just that it has been ice free in the past prior to any significant human footprint,. So, it’s likely that natural factors (just like with our climate) are the primary influencers/forcers.

    2. Not sure where you came up with your 73 meter figure on sea level. Simple science dictates that an ice-free arctic won’t equate to any significant rise in sea level. All the arctic ice floats in the ocean. There is no land mass up there. Whether the ice is frozend or melted, the level is already set. Put ice cubes in a glass to this principle in effect.

    3. Don’t take a page out of Al Gore’s debate denial book. There is ABSOLUTELY a debate about what causes climatic change and things like arctic ice changes. If the science were settled, we would be able to do basic things like predict the weather more than 24 hours in advance with something better than a 50% rate.

    If you are interested in open debate on this topic, check out a recent body of scientific evidence by Henrik Svensmark that makes sense with ALL the major aspects of our climatic history. You can read on the internet on his work about the interplay of the sun and cosmic rays and its global effect on cloud cover and therefore, global temperature change. He also has a book out with Nigel Calder called “The Chilling Stars”

  4. A couple of comments back:
    1. Your initial claim was that Arctic and Antarctic ice sheets were larger than last year and growing respectively. The former isn’t supported by data. The latter depends upon which part of Antarctica you’re talking about – the mass balance for the past few years has held more or less steady with increases on the Antarctic continent but decreases on the periphery. The Arctic will be ice free in the summertime at a much earlier date than anybody predicted just a few short years ago. That indicates that human forcing of climate change is having effects larger in scale and shorter in time than previously thought. The times at which the Arctic and Antarctic were ice-free in the past followed natural changes to atmospheric composition lasting hundreds to thousands of years. Humans are matching those forcing signals, but on much shorter time frames.

    2. I will point you to my comment again. I included the Antarctic ice sheets in addition to the Arctic ice sheets. Both poles have been ice-free in the past. But the forcing necessary to keep the Arctic ice-free would also work to decrease ice extent in the Southern Hemisphere as well. Such forcing goes way beyond an ice cube in a glass discussion. The last time both polls were ice-free, global sea levels were 73m higher than they are today, as discussed in the scientific literature. Any idea how many people would be affected by a mere 1m rise in sea level? How about 6 or 12? Maintaining a business-as-usual approach to climate change will put us well on the path toward decades to centuries of rising sea levels. The more we force the climate system, the more severe the resulting changes will be.

    3. There is no debate in the scientific community about the cause of anthropogenic climate change. The difference between climate forecasts and the capabilities of tomorrow’s weather forecasting are significant. The skill of climate forecasts are not and never will be perfect. That’s an inherent characteristic of a chaotic system. The recurring shortfall of climate forecasts is a noticeable underforecast of the extent of change, not an overforecast. A 24-hour weather prediction is anything but basic. I’m unsure where your 50% rate comes from. Perhaps a citation is available for this?

  5. Pingback: Climate in the News - 12/29/08 « Weatherdem’s Weblog

  6. Pingback: State of the Arctic - 3/16/2009 « Weatherdem’s Weblog

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