NASA GISS suggests aerosols play a large role in Arctic warming

9 04 2009

The Discovery Channel has “shark week”. With all the Arctic news items on WUWT, this is beginning to feel like “polar week”. Here’s an article about aerosols having an impact on the arctic from a surprising source.- Anthony

From Universe Today, Nancy Atkinson

Researchers used an electron microscope to capture these images of black carbon attached to sulfate particles. The spherical structures in image A are sulfates; the arrows point to smaller chains of black carbon. Black carbon is shown in detail in image B. Image C shows fly ash, a product of coal-combustion, that's often found in association with black carbon. While black carbon absorbs radiation and contributes to warming, sulfates reflect it and tend to cool Earth. Credit: Peter Buseck, Arizona State University
Since the 1890s, surface temperatures on Earth have risen faster in the Arctic than in other regions of the world. Usually, discussions on global warming tend to focus on greenhouse gases as the culprit for the trend. But new NASA research suggests about half the atmospheric warming measured in the Arctic is due to airborne particles called aerosols.

Aerosols are emitted by both natural and human sources. They can influence cli­mate by reflecting or absorbing sunlight. The particles also affect climate by changing cloud properties, such as reflectivity. There is one type of aerosol that, according to the study, [reduces] rather than increases in its emissions seem to have promoted warming. Read the rest of this entry »


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Categories : Arctic, aerosols

Was 2007 Arctic ice really a historic minimum?

9 04 2009

Since we have been on the subject of Arctic expeditions this week, I thought I’d share this short essay sent to me by WUWT reader “thoughtful”. It has some interesting perspectives from a NAVY expedition called “Operation Nanook” which is supported by the newspaper clipping from the Berkshire County Eagle (Pittsfield, MA) of October 16th, 1946. It was one of those rare times when a Northwest Passage appears to have been possible – Anthony

click for full sized article

click for full sized article

Looking at timelines of arctic exploration, we find that virtually nobody went there during the 30s and early 40s, despite that  correlating with the warmest temperatures on record (great Depression,  WW II, go figure).  Attached is an account of an arctic naval   expedition (Operation Nanook) that took place the summer of 1946, just  after WWII.  Vinther, et al (1) reports the merged JJA monthly temps were in the 7.3 to 7.4  deg C range in Greenland between 1931 and 1950.  In the 1990s, it was a full degree C lower.  The “norm” for  Thule in JJA runs somewhere around 4 – 5 deg C (1961 to current data).

Here’s another account from the same expedition: “On 4 July 1946, Atule headed for the frozen north as a member of   Operation “Nanook.” The purpose of this mission was to assist in the establishment of advanced weather stations in the Arctic regions and to aid in the planning and execution of more extensive naval operations in polar and sub-polar regions. In company with  USS Norton Sound (AV-11),  USCGC Northwind (WAG-282), USS Alcona (AK-157), USS Beltrami (AK-162), and USS Whitewood (AN-63),  Atule was to transport supplies and  passengers, conduct reconnaissance of proposed weather station sites,  train personnel, and collect data on Arctic conditions.

Atule

The US submarine Atule, during the Arctic studies in 1946

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Categories : Arctic, sea ice

WUWT Ice Survey Shows Thickening Arctic Ice

9 04 2009

Guest post by Steven Goddard

The WUWT Arctic Ice Thickness Survey has been conducted from the comfort of a warm living room over the last half hour, without sponsors, excessive CO2 emissions or hypothermia.  The data is collected from the US military web site http://imb.crrel.usace.army.mil.  All of the active military buoys show significant thickening ice over the past six months to a year, as seen below.


Location of military buoys
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Categories : Arctic, sea ice