During the first couple of weeks of 2014, people
all across Canada and the U.S. woke to find snow on their doorsteps and schools
closed. Now, this may not seem too big of a deal given that these are temperate
countries well-used to white winters, but these were no ordinary snow days.
This cold wave went far beyond the usual wintry chill, and temperatures in this
case fell to points of extreme; North Dakota clocked in at an intense -31
degrees Celsius, while even Hawai`i had to concede its tropical weather to -6
degrees— not including wind chill (Hodge, The Guardian, 2014)
This cold wave first made it through the north,
crossing borders from Canada into the United States before moving further south
and then east (Hodge, The Guardian, 2014). It shut down schools, offices, and
some public services, forcing people indoors and causing some states and
districts to release frostbite warnings. The harsh weather made it especially
difficult for people without adequate shelter or heating; reports came in of
escaped convicts turning themselves in for protection from the frost, and
several cities mobilized in order to keep their local homeless population out
of the cold (Walters, The Guardian, 2014).
But what caused this sudden and intense drop in
temperature? Some people— most famously (or infamously) Donald Trump in his
tweet about expensive global warming research and how supporting scientists are
stuck in ice” (Trump, 2014)— believe that this chilly weather disproves the
claims of scientists and global warming research. After all, how can global
warming exist if winters are now so much colder than before?
To answer this question, we need to first
understand what exactly this phenomenon is. According to meteorologists, this
cold weather is caused by something called a polar vortex, which is exactly as
cool as it sounds.
The polar vortex is a system of swirling cold air
that is usually contained at opposite poles of the globe. Strongest during the
wintertime, this cold air doesn’t usually venture into the more temperate
regions of the globe except during what Mitchell et al. termed a “weak vortex
event”, at which point the vortex is displaced from its usual position at the
Arctic (Mitchell et al., as quoted in WattsUpWithThat, 2014). During weak
vortex events, the probability of cold air moving into other regions increases
by about 50% (Kolstad et al., as quoted in WattsUpWithThat, 2014).
One of the more popular and contested theories
concerning this movement comes from Jennifer Francis, a professor at Rutgers
University, who posits that the increasing temperatures in the Arctic affects
the jet streams (wind currents in the region), subsequently bringing colder
weather further down south (Atkins, ThinkProgress, 2014). With the shrinking
ice caps and increase in water coverage area, more heat is radiated into the
atmosphere, disrupting the wind currents and causing changes in their ‘travel
paths’ (Fischetti, Scientific American, 2014).
While some reports posit these shifting jet
streams as the cause for the movement of the vortex, the researchers at
WattsUpWithThat.com hypothesize several potential factors, one of which is
geomagnetic activity and its correlation with how surface temperature is
distributed in arctic regions (Bucha and Våclav, as quoted in WhattsUpWithThat,
2014). This could means that global temperature changes, such as what we’re
experiencing now with large-scale climate change, could contribute to the movements
of this polar vortex.
These are only a couple examples of the wide
range of theories scientists and researchers are coming up with in order to
explain this strange weather phenomenon. More research is definitely needed in
order to understand this process, especially as the effects of this movement
are so drastic and immediate. By understanding the causation, we will be able
to better prepare ourselves for further phenomena and, if possible, prevent
them from happening again and causing billions in repair and rehabilitation.
References:
Hodge, K. (2014). Teaching the polar vortex: news and resources round-up. The
Guardian. Retrieved from http://www.theguardian.com/teacher-network/2014/jan/12/polar-vortex-climate-change-teaching-resources.
Walters, J. (2014). Polar vortex: temperatures drop below freezing in all 50 states.
The Guardian. Retrieved from http://www.theguardian.com/world/2014/jan/07/polar-vortex-temperature-freezing-all-50-states.
Trump, D. (2014). Retrieved from https://twitter.com/realDonaldTrump/status/418542137899491328.
N.A. (2014). A
displaced polar vortex and its causes. WattsUpWithThat. Retrieved from http://wattsupwiththat.com/2014/02/01/a-displaced-polar-vortex-and-its-causes.
Atkin, E. (2014). Everything you wanted to know about the ‘polar vortex’. Retrieved
from http://thinkprogress.org/climate/2014/01/06/3122491/cold-polar-vortex.
Fischetti, M. (2014). What is this ‘polar vortex’ that is freezing the U.S.? Scientific
American. Retrieved from http://blogs.scientificamerican.com/observations/2014/01/06/what-is-this-polar-vortex-that-is-freezing-the-u-s.
Laden, G. (2014). Go home, Arctic, you’re drunk. ScienceBlogs. Retrieved from http://scienceblogs.com/gregladen/2014/01/05/go-home-arctic-youre-drunk.
Luisa Narciso
2011-02507
STS THX
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