[wisb] Re: -- Speculation on Southwestern U.S. species birds in WI and nearby states
- From: John Idzikowski <idzikoj@xxxxxxx>
- To: Alan Stankevitz <alan@xxxxxxxxxxxxxxxxxx>
- Date: Mon, 7 Nov 2011 11:25:49 -0600 (CST)
I am showing the upper level jet chart to illustrate the movement of surface
weather systems guided by the strong upper level winds, not inferring that
birds move at these altitudes; it is then the circulation of winds around these
systems at or near the surface (925-850 MB) that I refer to- i.e. on the east
side of a low that will possibly facilitate the movement north of a vagrant.
There are lots of anecdotes from pigeon racers of changes in pigeon orientation
capabilities as there are lots of good correlates with vagrant events and
weather. I would add that if applying this to wild birds we might expect a
widespread vagrancy pattern across species not normally vagrating in fall and
the occurences would not be regional- our present bag of vagrants all have
precedent as vagrants in many falls to different regions. We should look at
archived data on such solar events in relation to vagrancy. Perhaps the obvious
question is can solar storms have an effect on the jet stream?
http://www.ehow.com/info_8412297_solar-flare-effects-jet-stream.html
John I
----- Original Message -----
From: "Alan Stankevitz" <alan@xxxxxxxxxxxxxxxxxx>
To: "John Idzikowski" <idzikoj@xxxxxxx>, wisbirdn@xxxxxxxxxxxxx
Sent: Monday, November 7, 2011 10:51:26 AM
Subject: Re: -- Speculation on Southwestern U.S. species birds in WI and nearby
states
In response to John's comments, yes...solar flares do effect the
magnetic lines all the way down to ground level. There is a device
called a magnetometer which measures magnetic field strength and they
do record geomagnetic storms at ground level.
I agree that winds do play a role in bird migration and large storms
can sometimes effect the movement of birds. Not to be nit-picky but the
jet stream chart you link to is typically at 25,000 ft. or higher. Most
neotropical birds migrate at altitudes of 500-6,000 ft. It would be best
to follow the 850 MB chart for bird migration. (850 MB chart is ~5,000 ft.)
I'm certainly not stating that all or any vagrants occur from
geomagnetic storms, but I believe it is certainly possible. If anything,
the next time there's large number of rare birds showing up during a
migration it would be interesting to check out what the sun was doing at
the time of the outbreak. We certainly have a few more years of
potential solar flares coming up. It will be interesting to see if there
is any further correlation...or not.
Interestingly, you brought up the fall of 2000. That was exactly 11
years ago. The sun cycles through an 11-year sunspot cycle and it was
very active in 2000 and there was a geomagnetic storm from Oct 3 -7, 2000.
Thanks for the response,
Alan
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