Fire Earth

Mass die-offs from human impact and planetary response to the assault could occur by early 2016

Posts Tagged ‘mid-latitudes’

Arctic Ice Affects Global Climate, Weather

Posted by feww on March 17, 2010

Arctic ice-melt is not just a local issue, it affects climate, weather globally

Melting sea ice may appear to be  or local at worst regional problem, but NOAA says that changes in the Arctic ice cover also influence weather in the mid-latitudes, where the majority of humans live.


Satellite images show a clear acceleration in the Arctic ice loss for the past 30 years.  For additional information visit
Will the Arctic be free of summer ice in 30 years?

Just about every model available for the Arctic ice cover in the future predict a continuation of the present pattern, an acceleration in the ice melt.

What happens when the open arctic waters absorb the additional heat?


The additional heat impacts the Arctic winds and therefore the Arctic atmosphere, increasing the variability and unpredictability of global wind patterns. For additional information visit How the loss of sea ice leads to a warmer Arctic

Cold arctic winds move to mid-altitude regions of the globe, spawning violent winter storm in the U.S. and Eurasia.

Teleconnections impact mid-latitudes

Warmer temperatures that result from huge losses in the sea ice cover give rise to higher pressure surfaces above the North Pole which in turn impact large scale wind patterns over the Northern Hemisphere. “Climate models show these connections with cold air moving south, producing low pressure areas and unusually cold winters in the eastern U.S. and eastern Asia, and cooler than usual weather in late winter from Europe to the Far East.”  For additional information visit How changes in the Arctic impact weather and climate in Europe, Asia and the US.

See also:  Transitory Impact of AO is the ‘Good News’

How much warmer is the Arctic?

In the figures below, red, yellow and green colors indicate areas over the Arctic region where autumn near-surface air temperatures were from 2 to 6°C warmer than the normal values observed prior to 2002.


Anomalies for autumn in 2002-2005 represent deviations from the normal near surface air temperature values which were observed from 1968-1996. Figure from Overland and Wang via NOAA

Anomalies for autumn 2007-2008 represent deviations from the normal near surface air temperature values which were observed from 1968-1996. Figure from Overland and Wang via NOAA


Anomalies (above) represent deviations from normal pressure surface elevations over the Arctic. Figure from Overland and Wang via NOAA

Warmer Arctic changes the Arctic atmosphere, impacts global winds

The elevated pressure surfaces above the North Pole persist into early winter and impact large scale wind patterns over the Northern Hemisphere, allowing cold are to move southward.

Figure (below) shows the changes in the Northern Hemisphere wind fields that are associated with late autumn surface air temperature and earlier sea loss. Blue and purple colors indicate areas with wind deviations below normal. Note the much reduced winds north of Alaska and western Canada.2

The reduction in winds opposes the usual atmospheric circulation patterns, allowing outbreaks of cold Arctic air to move southward.

It must be noted that there is considerable year-to-year variability in pressure fields, and that modifications of mid-latitude weather by wind patterns associated with sea ice reduction can be complex (involving storm track and longwave interactions).

However a consequence of the changes in Arctic atmospheric temperature and pressure, following loss of sea ice, is increased likelihood of cold air moving southward via teleconnections to impact weather at mid-latitudes.

As summer Arctic open water area increases over the next decades, we anticipate an increasing influence of loss of summer sea ice on the atmospheric northern hemisphere general circulation in following seasons with resultant impacts on northern hemisphere weather. For more information visit source: Loss of summer Arctic sea ice … and  Arctic Future Web site


Anomalies (above) represent deviations from normal east-west winds over the Arctic. Figure from Overland and Wang via NOAA

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Posted in Arctic winds, Climate Change, Eurasia winter, Teleconnections, US weather | Tagged: , , , , , , | 1 Comment »

 
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