Ticker for July 26, 2007

                
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July 26, 2007      July 26, 2007      July 26, 2007      July 26, 2007



A Correction

It appears that yesterday's Ticker was hastily written, clumsily
worded and poorly edited (imagine that). More than one reader noted
that we may have left the impression that Oklahoma's solar radiation
values are down in 2007 because the Sun itself is dimmer.

Rest assured: the Sun is still generating its relatively standard
output, and is still on track to swallow and destroy our planet
in a fiery, apocalyptic maelstrom some time in the next few billion
years.

The "dimming" that we've observed so far this year is due to a
colossal increase in cloud cover, that blocks the Sun's rays
before we experience.


Purple Reign

Yesterday, we were digging around for some Ticker material, and
came across one of the best radar-indicated explosions of purple
martins we've ever seen. If you can handle a 1.5 MB download,
here's a great movie from sunrise yesterday:

https://content.mesonet.org/ticker/archive/20070726/martins.mov

If not, here are some stills taken every 20 minutes:







More explanatory info is included below, but a few things to notice
in these images are:

1. Notice that the rings explode in an east-to-west sequence,
mirroring the rising sun.

2. Notice that, at about 7:20 am, a SECOND ring emerges just
north of Little Rock (north-central Arkansas).

Cool stuff! A fuller explanation of purple martin behavior and the
radar phenomenon is provided in a set of Tickers from August 2005:

http://ticker.mesonet.org/select.php?mo=08&da=08&yr=2005
(the original observations)

http://ticker.mesonet.org/select.php?mo=08&da=09&yr=2005
(velocity data and some horrible bird-insensitive punnery)

http://ticker.mesonet.org/select.php?mo=08&da=11&yr=2005
(the biological explanation of purple martin behavior)