Sunday, December 30, 2012

Student Voices - #3

Future Weather Patterns and the
Disappearing Arctic Ice Cap 

Over the last four years, as a student in the Environmental Science and Studies Program of Moravian College, Bethlehem, PA., I have studied about the environment and particularly about global climate change. One aspect that I find particularly interesting is the increasing occurrences of “record breaking” weather events over the last several years. While some may call this “global climate change”, a “phenomenon”, or even just the “normal pattern of the earth’s climate”, one thing is sure: weather and climate change are indeed occurring.  Until recently, I was baffled when pondering the reasons why this way occurring in the Northeastern United States where I was raised. It was not until recently that I believe to have learned the explanation for these record breaking events, at least in the northern hemisphere.

Currently, there has been significant evidence to prove that indeed the Arctic ice sheet has been disappearing over the last half century. [1, 2] While currently, the overall surface area of summer arctic sea ice has disappeared by nearly 40% since the 1980’s resulting in a loss of nearly 1.3 million square miles of ice. [1]  In addition, it is even more important to examine the change of volume of ice over this time for this reveals a more accurate description of the actual ice loss. When arctic ice volume is measured, the results are even more dramatic. As Fen Montaigne, (senior editor of Yale360) reports, 

“University of Washington’s Pan Arctic Ice Ocean Model Assimilation System (PIOMAS) estimates that sea ice volumes fell in late August to roughly 3,500 cubic kilometers — a 72-percent drop from the 1979-2010 mean”. [2] 

As the scientists revealed, there has been a significant reduction in the amount of Arctic Sea ice over the last 3 decades. (It is important to note that I am not arguing as to the original cause of this melt but merely stating that this has happened and examining the effects of this ice loss). 

Correlated with this loss of ice has been increased record setting weather. While many claim these to be “global warming”, I prefer to look at these as “climate change” for not all of these effects are increased temperatures. For example, while Russia over the last several years has experienced drastic record setting heat waves, Alaska and Western Europe have both experienced the opposite with record setting winter cold temperatures. [1]  In addition, places such as the Midwestern United States have seen both record setting high and low temperatures. Also, apart from temperature changes, the Northeastern United States has seen recording breaking snowfall over the last year. Personally, I witnessed Bethlehem, PA receive a record breaking 6” of snowfall last year on October 29, 2011 as well as Smugglers Notch Ski Resort in Vermont receive over 70” of snow in January 2012 due to a Nor’easter. While as an avid snowboarder I thought this was amazing, it was equally as startling when examining from the perspective of an environmental scientist observing unusual weather patterns.

As a result, there is one theory proposed by Jennifer Francis (Institute of Marine and Coastal Sciences, Rutgers University Research Professor) whom explains the reasoning for all of the above record breaking circumstances [1]. Her theory is that as the arctic ice melts, northern arctic temperatures rise which results in an increased oscillation of the northern Jet Stream. This is called “arctic amplification.” [1] As the Jet Stream, which separates the cold arctic air from the warm mid-latitude air, increases in north-south oscillation, its eastward movement (due to the Coriolis Effect), is significantly slowed. This results in the elongation of weather patterns. This would explain the unusual +70” of snowfall last January I witnessed firsthand for the Nor’easter over Vermont had a longer duration period over the Northeastern United States. The second effect of the Jet Stream oscillation is the carrying of cold arctic air further southward as well as the warmer mid-latitude air further northward. [1] When combined with the slowed eastward movement of the Jet Stream, these relatively new weather patterns result in extreme high and low temperatures across different areas of the globe. As Jennifer Francis explains in her 2012 analysis Linking Weird Weather to Rapid Warming of the Arctic:

Deep troughs in the jet stream hung over the U.S. east coast and Western Europe during the winters of 2009/2010 and 2010/2011, bringing a seemingly endless string of snow storms and teeth-chattering cold. In the early winter of 2011/2012, in contrast, these same areas were under ridges, or northward bulges of the jet stream, which brought unusually warm and snowless conditions over much of North America. At the same time, however, a deep trough sat over Alaska, dumping record snows.

As it was explained above, the Jet Stream Oscillation was the result of the various record breaking weather patterns shown over the last few years across the Northern Hemisphere. In conclusion, the arctic ice cap has continued melting at alarming rates over the last 3 decades. While this is this leads to warmer temperatures in the arctic region, the effects which it places on lower latitudes has been debated. Scientific data such as record high temperatures in certain areas while record low temperatures in another could be scientifically used to debate opposing hypothesis as to the weather effects of the arctic ice melt, the true explanation for this potentially contradicting data is explained by Jet Stream oscillation from arctic amplification. This process effectively explains the large variance of weather patterns and record setting events seen across the northern hemisphere over the last decade, some of which I had witnessed personally.

Works Cited

[1]        Francis, Jennifer. "Linking Weird Weather to Rapid Warming of the Arctic." Yale Environment 360. Yale Environment 360, 05 May 2012. Web. 29 Nov. 2012. 

[2]        Montagine, Fen. "Arctic Tipping Point: A North Pole Without Ice." Yale Environment 360. Yale Environment 360, 30 Aug. 2012. Web. 29 Nov. 2012. 

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