For the past two winters, the continental United States has
experienced harsh weather conditions with unusual amounts of precipitation in
the form of snow. Meteorologists have
established that arctic-born weather has been directed to the Northeastern, Midwestern
and even Southeastern continental United States as a result of a shift in the
direction, depth and pattern of the jet stream described as “wavy.”
Dr. Jennifer Francis, a climatologist, and her colleagues at
Rutgers University in collaboration with Dr. Steven Vavrus from the University
of Wisconsin at Madison have published data establishing a connection between
warming in the Arctic Ocean and the extreme winter weather in the lower
latitudes.
Ordinarily sea ice exerts an influence on global temperature
by its ability to reflect back solar radiation into space on account of its
whiteness through what is referred to as the albedo effect. However, as a result of the gradual warming
of the planet due to the accumulation of greenhouse gases, the temperature in
the Arctic has increased at twice the rate as the rest of the earth. This increased temperature is accelerating
the melting of Artic sea ice. As this
sea ice melts, it reduces the albedo effect and results in increased warming
and therefore the further melting of sea ice.
This cycle of increased warming is referred to as negative
feedback.
It seems that this warming trend in the Arctic has disrupted
normal climate conditions in the following way - cold air that is usually contained
within the Arctic region by so-called “polar vortex winds” has moved southward
into the mid-latitudes as a result of the high pressure that is a direct
consequence of the enhanced melting of the sea ice. Accordingly, the lower latitudes have experienced
unusually extreme winter weather.
If this explanation is proven to be correct for seasonal
aberrations in weather in the lower latitudes, then these changes would suggest
a permanent alteration in weather patterns for the regions impacted.
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