Journal archives for November 2020

November 24, 2020

Brief "Birding by Radar" tutorial

Birding by Radar Birds migrating at night can often be seen on radar on clear nights, especially during nights of heavy migration. Other things known as "ground clutter", such as dust or smoke, can also appear on radar during clear nights. Usually the easiest way to determine whether you're looking at birds or not is to check the wind speed and the speed of the target on the radar; if the target is moving faster than the wind, it's probably not light particles (dust, smoke, etc.) being picked up by the radar, as it would generally be traveling at the same speed as the wind. Visit www.rap.ucar.edu/weather/radar (my favorite site) Choose either velocity mode or reflectivity mode, date/time, and local radar station from the map. VELOCITY mode shows the speed and direction that the target is traveling; warm colors show objects moving away from the radar, cool colors show objects moving towards the radar, and objects moving parallel to the radar will show up as a gray bar intersecting the radar, because they are neither moving directly towards or away from the radar. The direction that the birds are migrating in can be determined by looking at the direction shown by colors as well as the position of the gray band. The birds are traveling at a right angle to this band. The speed can be determined by checking the current wind speed/direction of that area, and comparing that to the speed shown on the radar image. Birds generally travel 10-15 mph faster than the wind. REFLECTIVITY mode shows the density of the target on the radar. Below is an image of migrating birds appearing on the radar at night (velocity mode) Radar image from night of 09/11-09/12/2020, bird migration. Portland Maine
Posted on November 24, 2020 22:41 by wbarker26 wbarker26 | 0 comments | Leave a comment

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