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Re: [Phys-L] Polar Vortex

The quote is from an article in Universe Today - http://www.universetoday.com/107814/satellite-image-of-the-polar-vortex-over-the-us/ - If you can find a political affiliation please let me know. The word "pole" is in the quote - I am not interpreting anything. The graphics that I saw on CNN placing the "vortex" at the pole was not an "interpretation" on my part. If you look at the Wiki article, it is clear that the newly coined "vortex" is not over the pole but over southern Canada.

My point is that the media are running away with this new term with no idea what it actually refers to. They are merely quoting one another and an incorrect concept is now being spread like a game of telephone - getting less correct on every retelling. Whoever wrote the Wiki article basically has it correct. The "vortex" is not over the pole - it is subpolar - and it is a normal occurrence that happens year-round. But most importantly, it is not a "vortex" at the pole that somehow split due to global warming. It was never at the pole in the first place. At any given time of year you can find these lows on the 500 mb circumpolar charts - http://weather.noaa.gov/pub/fax/QTUA11.TIF - they form in place - they don't split off from a master Vortex.

The thing that struck me as amusing is that global warming was being used to explain a phenomena that doesn't actually occur in the first place - that is how sloppy reporting by the media has become. The media try to hype every event as something unusual and exciting that has never occurred before. Those of us who grew up in the 40's and 50's remember lots of cold weather like we are experiencing at the moment. It's just part of weather and doesn't need any particularly unusual causes to explain it. A warming earth is still going to experience weather extremes at various locations - both warm and cold - just as a cooling earth would.

Bob at PC

-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@phys-l.org] On Behalf Of brian
whatcott
Sent: Tuesday, January 07, 2014 2:29 PM
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] Polar Vortex

On 1/7/2014 10:20 AM, LaMontagne, Bob wrote:
The current buzzword used by the media is "polar vortex". It appears to be
a rather recent term, as no meteorology texts refer to it.

NASA explains that the polar vortex is a "whirling and persistent large area
of low pressure, found typically over both North and South poles."

A quick perusal of introductory meteorology texts finds reference
instead to the Polar High. This refers to the fact that the coldness
of the air over the poles, combined with the earth's general
atmospheric circulation (rising air over the equator and descending
air over the poles) gives rise to a generally high pressure region at
the poles - not low pressure. The descending air over the poles flows
southward at lower altitudes and turns somewhat to the west due to the
Coriolis effect (momentum conservation basically). Eventually this air
reaches warmer air to the south (Ferrell cell) and air rises where the
air flow in the two air masses converge - giving a ring of generally
low surface pressure at the latitude of the northern United States and
Southern Canada - well south of the pole. At high altitudes (upper
troposphere to stratosphere), the temperature difference between the
two air masses produces a large density difference between the two air
masses and a strong pressure gra
di
ent directed from the warm air mass to the colder polar one. This
strong gradient, in conjunction with the Coriolis effect, produces the
jet stream - flowing generally from west to east. The polar air is
unusually cold this year so the jet stream is very fast (180 knots in
places right now). It also is dynamically unstable and wanders
northward and southward along the boundary of the two air masses. As
it changes direction from meandering toward the southeast to a flow to
the northeast, there will be a low pressure to the north of the jet
stream - associated with its turn to the left. This is quite visible
in the upper air charts at the moment:
http://weather.noaa.gov/pub/fax/QHUA15.TIF

There is nothing unusual or novel about these low pressure regions. They
are present all the time around the jet stream - which is well south of the
poles.

The reason I bring all this up is because of all the incorrect meteorology and
physics that is being bantered about in the media and - wait for it - how it is
supposedly connected to global warming. I have now twice seen graphics of
a huge supposed "polar vortex" of low pressure that supposedly resides over
the poles (remember the Polar High), followed by an explanation of how
global warming has split the main vortex into two vortices that have
wandered south over Southern Canada and the old Soviet Union, causing the
extremely cold weather there.

This is just silliness. The low pressure flow we are seeing over Canada is
often there- winter and summer. In colder winters than usual, the
temperature gradient just intensifies these large scale lows producing what
we all know in the US as "Alberta Clippers" or the "Montreal Express" - cold
air coming in from over the Canadian plains. The media has simply
repackaged these as the "Polar Vortex". As many have pointed out on this
list, there is a difference between weather and climate. While global
temperatures have risen over the past century, that has nothing to do with
the weather we are currently experiencing.

Bob at PC
It appears that what Bob believes NASA defines as the locality of the polar
vortices and what NASA defines as the locality of those vortices differ.

This Wiki seems to do a reasonable job of discussing the Polar High and the
Polar Vortex (low).

http://en.wikipedia.org/wiki/Polar_vortex

It has a reasonable number of supporting references which do not seem to
originate with sources of a particular political orientation.

Brian Whatcott Altus OK



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