Radar?Ornithology?was developed at Clemson so that is the sort of mother site. ?For us it's just an interesting side-effect of weather radar but they are able to obtain computer records of radar tracks and analyze them in great detail. ?When you read the "How to" even you will be able to estimate the number of birds per cubic mile and their speed of advance at various altitudes and the heading they are on. ?From those numbers combined with known migration patterns the?scientists?can come up with reasonable guesses as to the the species that make up the cloud. ?For instance we know that shore birds are in full migration right now. ?We know the speeds and altitudes that shore birds prefer and the normal heading they will take so it's reasonable to assume that a large portion of the birds making their way up the coast at those speeds and altitudes are shore birds. ?So the gross numbers can be?calculated?from the strength of the return.?

One of the most thrilling things is to watch the Gulf Coast. ?On Fall evenings beginning at around 7 PM PDT or 9 PM on the Gulf you will begin to see hundreds of thousands of birds make their jump-off for the harrowing 600 mile over water journey across the gulf. ?This time of year if you tune in to those stations in the morning you can pick out the pattern formed by birds that safely made the crossing in the U.S. over night. ??

Sadly you can also watch the wind direction and strength and determine when the birds are in trouble. ?In the Fall the birds know the weather fronts behind them. ?Heading south they wait on this side for an offshore wind and ride it across. ?In the spring they don't have radar to let them know about fronts they might fly into. ?If they get hit by a front that sweeps through the gulf from the north, which of course creates a headwind, many of them don't make it and it's especially hard on small birds which fly low and slow anyway. ? That's what creates a fall which is fun for birders but a fall actually means that lots of birds became?exhausted?and died on the way.?
?
Ray Holden
Olympia, WA




________________________________
From: dave templeton <crazydave65 at gmail.com>
To: Tweeters <tweeters at u.washington.edu>
Sent: Thursday, April 19, 2012 7:41 AM
Subject: [Tweeters] results of quick search where term = radar ornithology


hi:

using the term radar ornithology on dogpile yields pages of sites.? among the more promising are these:

http://virtual.clemson.edu/birdrad/comment.htm

http://gcbo.org/default.aspx?MenuItemID=157&MenuGroup=Home&&AspxAutoDetectCookieSupport=1

http://featherflower.blogspot.com/2009/04/radar-ornithology.html

http://ebird.org/content/ebird/news/radar




pulled from the last cite:



The basic metrics are here, and this terminology is used in the

BirdCast migration reports and BirdCast forecasts:

??? Minimal migration: <5 dBZ -- fewer than 59 birds per cubic kilometer
??? Light migration: 5-10 dBZ -- approximating 59-71 birds per cubic kilometer
??? Moderate migration: 10-20 dBZ -- approximating 71-227 birds per cubic kilometer
??? Heavy migration: 20-30 dBZ -- approximating 227-1788 birds per cubic kilometer
??? Extreme: >30 dBZ -- more than 1788 birds per cubic kilometer (actually occurs at some times in very rare circumstances)

regards,

t

--
dave templeton
fall city, wa

crazydave65atgmaildaughtcom

"Don't worry about the world coming to an end today; it's already tomorrow in Australia."? Charles Schultz

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