Performance of C-band Radar in Tropics

Rain path attenuation has a non-negligible effect on C-band radar observations of heavy rainfall. This was one of the main reasons why the most of the weather radars used in Tropics operate in S-band, which considered to be almost immune to path attenuation. During the last decade the dual polarization technology has became robust and operationally used on C-band radars. Attenuation correction of radar observations using dual-polarization radar measurements, allows to extend applicability of higher frequency radars, like C-band, to monitoring of tropical rainfall. Given the current technology and algorithm status we expect that we can compensate for the attenuation in most of the cases where radar signal is not completely extinct.

In this paper we analyse usability of C-band radars in Tropics by using such statistical measures as probability of exceedance of attenuation. Using Kdp observation collected in Tropical area for a period of local summer season we construct exceedance of attenuation curves. We convert Kdp to specific attenuation using relations reported in literature. Those curves show what percentage of the time we would expect to see attenuation of more than a given value at a given range. Using those we can assess probability of complete extinction of a radar signal. Furthermore, we contrast observation in Tropics to ones in mid-latitudes. We will show how the statistics of Kdp as an effective indicator of attenuation will vary between the data sets measured in the different climates and how effectively attenuation can be corrected.