Final answer:
Virga is detected on radar in both clean air mode and precipitation mode. In clean air mode, radar can detect the presence of virga. In precipitation mode, radar can differentiate between virga and actual rainfall on the ground.
Step-by-step explanation:
Virga is detected on radar in both clean air mode and precipitation mode.
In clean air mode, radar can detect the presence of virga, which is precipitation that evaporates before reaching the ground. The radar will show echoes or returns indicating the presence of precipitation, but the absence of rainfall at the surface.
In precipitation mode, radar can also detect virga. The radar will show echoes or returns indicating both the presence of precipitation and the location at which it is falling. However, in this mode, the radar can differentiate between virga and actual rainfall on the ground.