Bugs are associated with what type of ZDR values?

Bugs, or insects, exhibit specific radar signatures that are characterized by their relatively high ZDR (differential reflectivity) values. This is due to the fact that insects are often small and have a high aspect ratio, which means they tend to reflect more horizontally polarized radar energy compared to vertically polarized energy.

High ZDR values indicate a greater reflectivity in horizontal polarization than in vertical polarization, which is typically found in elongated or flat objects, such as bugs, when observed by radar. This makes them easier to detect in weather radar data, particularly when they are flying in swarms.

In contrast, lower ZDR values would be more indicative of spherical particles like raindrops, whereas negative or undefined ZDR values aren't characteristics of bugs and are associated with other phenomena. Consequently, the association of bugs with relatively high ZDR values is a key feature used in radar meteorology for identifying biological targets.