Sunday, August 15, 2010
I wake up- the first thing I typically do is take a look outside to get a feel for the weather. Cloudy- no wind, and no precipitation. Is it going to rain today?
Recently, I've been visiting the website of the National Weather Service Forecast Office in Wilmington Ohio, for my daily weather predictions. I particularly enjoy the area forecast discussion. You get a feel for just how much room for error is built into our daily forecasts.
But this morning, something new caught my eye. A link titled "Roosting Birds Detected on NWS Doppler Radar". After a quick click I was led to several animated radar maps showing expanding doughnut shaped patterns around NWS radar sites. According to the NWS, the radar is recording the pattern of birds flying away from their roosts at dawn. And they postulate that these birds are most likely purple martins.
At first, I questioned the doughnut pattern- why does it look like all the birds are radiating out from each station? The meteorologist explains this by saying "The unique doughnut pattern of these roost rings is the result of the martins departing their roosting site in all directions, roughly in equal densities". That doesn't explain the pattern to me, but he is saying that the pattern tells them that the birds are radiating out in all directions. One last very interesting tidbit of information- in the map above, the author points out how the doughnuts begin first in the east, then gradually move west, corresponding with the rising sun. Pretty cool, eh?