Despite the effort of hurricane Sandy the U.S. Northeast
experienced its second driest November in over a century, receiving on average
only 1.04 inches of precipitation. This November will also be recorded as the
coldest average since 1997, being 2.5 degrees colder than normal. It is not
unnatural to have a few outliers of any measurement, weather is no exception.
But should this record setting dry month alarm us, or should life continue as
usual? Science has been increasing its understanding of climate change and the effect it has on weather patterns. Changes in the path of the Polar Jet Stream is an important reason why these changes of precipitation and temperature are happening.
The jet stream plays a significant role in the weather we experience, depending
if they it shifts higher or lower than typical in terms of latitude. If the jet stream is lower
than its typical position, then it will bring with it the cold artic air from
out of the north. If it is higher, then the warm moist air from the gulf will
travel higher up in latitude and farther inland, bringing humid, hotter
weather. This is due to Rossby waves, or a meandering of the jet stream. The jet stream has the power to turn rain forests in to deserts (in
its most extreme form and over many years). In Africa, drought has been occurring
for the past several years and science has beginning to point to the shifting jet
steams as the cause.
We can use the Palmer drought severity index (PDSI) forecast
to help us in predicting where drought prone areas are, or where a drought is
developing. And over several years we can see patterns develop. This is one
aspect of the engineering paradigm, forecast potential hazards. Another part is
looking at how drought would affect
an area like the northeast coast. This isn’t an area where we have much
agriculture, so famine is an unlikely result. But with a decrease in fallen precipitation
there comes an increase with ground water usage which further depletes the already
low levels. Therefore we can combat drought in this area, but only at the cost
of our fresh groundwater. We need to fix the problem at the source; which is to
understand the extent of our anthropogenic actions on the earth and its
systems so that we can minimize them.
http://www.sciencedaily.com/releases/2012/12/121205142325.htm
