The Clear-Air Coastal Vespertine Radar Bands

Abstract

It is known that the insects observed in the lower layers of the atmosphere produce radar echos and that their spatiotemporal distribution is strongly influenced by the meteorological conditions and the thermodynamic structure of the atmosphere. However, the available information on the subject essentially deals with the continental zones. Observations carried out from the Atlantic coast with a polarimetric Ka-band Doppler radar are used to show the existence of large band-shaped areas of insects above the coastal Atlantic Ocean, which has a reflectivity 3 ? 10?2 times higher than the values usually observed inland. The insects collectively fly with a common heading. These bands form at dusk and are connected with the coastal atmospheric circulation, which carries along the local insect population.