Ph.D. Student - Earth System Science (UC Irvine), B.Sc. - Atmospheric Sciences (Cornell University)
By: Zachary Labe , 4:49 PM GMT on June 13, 2014
13 June 2014
The Coming Global Earth
A few years ago, I picked up a fictional book at the library titled "The Coming Gobal Superstorm" by Art Bell and Whitely Strieber. For those familiar, the plot is the inspiration behind the Hollywood hit The Day After Tomorrow. To summize the plot, global climate change leads to the eventual shutdown of the Thermohaline Circulation (THC) signaling an ice ago across North America and Europe.
(Courtesy of NCDC)
It is widely understood that Earth's desire for thermal equilbrium, despite unequal heating, is partially achieved through the concept of the THC when heat is transfered through these global ocean conveyor belts. However, the book theorizes that a disruption is evaporation and salinity properties across the North Atlantic would create a disruption to the gulf stream and hence and break in the conveyor belt. Heat from the equator would no longer be transported poleward and therefore bye, bye temperate climate Europe. A work of science fiction most would conclude, however... paleoclimate records from ice cores in Greenland suggest that this has indeed occurred in the past. During the last ice ago, temperatures across Greenland cooled nearly 7 degrees Celsius. Changes in sea surface temperatures (SST) and salinity likely resulted in a displacement of the Gulf Stream. In any case, it is likely the THC will collapse ago over the next few centuries due to natural cycles. The good news is that present climate models suggest that any temperature or precipitation anomaly effects will be for the most part minimal and/or localized to severe cooling across Greenland.
(Couresty of UK Met Offce Research Division)
The concept of heat balance is certainly more complicated than ocean currents, and in fact much of the basis behind it lies in simple radiation laws. Using this simple model of the atmosphere we can conceptualize incoming and outgoing radiation through the atmosphere in relation to temperature based on the Stefan Boltzmann Law.
(Goosse H., P.Y. Barriat, W. Lefebvre, M.F. Loutre and V. Zunz, (date of view). Introduction to climate dynamics and climate modeling.)
Alpha=Earth's albedo (approximately 0.3 [unitless])
So= Earth's solar constant (approximately 1367 [W/m^2])
Epsilon= emissivity (ratio of amount of radiation absorbed by object compared to that of a blackbody)
Ta= Effective Temperature (Temperature of Earth given no radiation absorption) (Approximately 255 [K])
Ts= Surface Temperature (Actual mean temperature of Earth) (Approximately 288 [K])
Sigma= Stefan's Constant (Approximately 5.670373×10−8 [W m−2 K−4])
This basic model represents that of an atmosphere with one layer greenhouse gas absorption (not Earth). Since the amount of incoming and outgoing energy must stay constant so therefore an increase in layers causes an increase in T (Earth).
Quite simply, I think it was this beautiful mathematic relationship, which can ever-so simply model the entire Earth's atmosphere's transfer of energy, is the reason I have switched gears into new studies and interests. My current research also uses simple inputs of Tmax and Tmin over the course of a year for a given climate station to derive synoptic parameters and eventual indices revolving around the timing onset of Spring. Using these relationships, we can track trends over x length of time from Earth's potential energy correlated to the timing of spring based on phenological data. It is quite astounding how accurately we can model these relationships.
My culminating final year of study will focus on these climatological effects in hopeful preparation for a PhD program beginning Fall 2015 in small and large spatial scale climatology. While my interests still include some forecasting (particularly long-term), I think my skill sets and essentially my enjoyment will rather be fulfilled in research academia, at least for the time being. This slightly convoluted and disorganized blog gives a rather quick overview of my absence here during the past few months. Over the course of the summer, I hope to write a weekly blog detailing a range of topics from weather forecasts to short overviews of topics covered in my courses. I have gained quite a bit of respect for the complicated arithmetic that unfolds to deliver our weather forecasts, and my hope is to share a bit of this with all with you. Without a formal education in the field, it is unfortunate that enthusiasts never get to see the beauty behind the mechanics and physical properties of the Earth sciences.
Lower Susquehanna Valley Doppler...
(Courtesy of WGAL)
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The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.