NOAA: Arctic Report Card -- Update for 2009

Dear Readers,

The post below is number 1,500 since this blog started in 2007.  Never in my wildest dreams could I have imagined that I would have posted so many articles here.  Nor could I have imagined that this blog would receive an average of nearly 500 visitors per day, with upwards of 800 pages per day viewed, now bringing total page views to nearly 200,000.

Over time, as the scientific articles have accumulated here, this blog has become a database for the advanced layperson seeking more knowledge of climate science.

I admit that I cannot nor do I try to cover all of the vast number of aspects of the science of climate change.  The blog's focus has been on the Arctic and on changing patterns of atmospheric and oceanic circulation all around the globe, although many other subjects are covered.

It is to be hoped that the blog's contents have been found useful by you, the reader.

I salute all of you for seeking the truth.

Sincerely,

Tenney Naumer

NOAA: Arctic Report Card -- Update for 2009

Warming of the Arctic continues to be widespread, and in some cases, dramatic.

Linkages between air, land, sea, and biology are evident.  

Link to first webpage here:  http://www.arctic.noaa.gov/reportcard/

Please click on the headings below to go to the various sections of the report.

Atmosphere
Large scale wind patterns impacted by loss of summer sea ice

There is evidence that, by creating a new major surface heat source, the recent extreme loss of summer sea ice extent is having a direct feedback effect on the general atmospheric circulation into the winter season (Francis et al., 2009). Fall air temperature anomalies of greater than +1.0 °C were observed well up into the atmosphere (Figure 3A), when averaged over 2003–2008 relative to a 1968–1996 base period. The higher temperatures in the lower troposphere decrease the atmospheric air density and raise the height of upper-air-constant-pressure levels over the Arctic Ocean (Figure 3B). These increased heights north of 75° N weaken the normal north-to-south pressure gradient that drives the normal west-to-east airflow in the upper troposphere. In this sense, the effect of higher air temperatures in the lower Arctic atmosphere is contributing to changes in the atmospheric circulation in both the Arctic and northern mid-latitudes. For example, Honda et al. (2009) suggest a remote connection between loss of Arctic sea ice and colder temperatures over eastern Asia.

The climate of the Arctic is influenced by repeating patterns of sea level pressure that can either dominate during individual months or represent the overall atmospheric circulation flow for an entire season. The main climate pattern for the Arctic is known as the Arctic Oscillation (AO) with anomalous winds that blow counter-clockwise around the pole when the pattern is in its positive phase. A second wind pattern has been more prevalent in the 21st century and is known as the Arctic Dipole (AD) pattern (Wu et al., 2006; Overland et al., 2008). The AD pattern has anomalous high pressure on the North American side of the Arctic and low SLP on the Eurasian side. This implies winds blowing more from south to north, compared to the AO, and increasing transport of heat into the central Arctic Ocean. The AD pattern occurred in all summer months of 2007 and helped support the major 2007 summer reduction in sea ice extent (Overland et al., 2008). Fall 2008 and winter/spring 2009 showed a return of the AO pattern, but also considerable month to month variability in the presence of these various climate patterns.

Sea Ice
Multi-year sea ice is being replaced by first year sea ice

Ocean
Upper ocean remains warm and less salty

Land
Increased runoff in Siberia, less snow in North America

Greenland
Ice sheet loss continues

Biology
High Arctic species impacted by loss of sea ice

Link to complete report (pdf file):  http://www.arctic.noaa.gov/reportcard/ArcticReportCard_full_report.pdf