Rain-Induced Attenuation at Tropical Rainfall Measuring Precipitation Radar Channel over a Few Tropical and Extra-Tropical Locations in India

  • Thirumala Lakshmi K, Rajasri Sen Jaiswal


In this paper, the authors have attempted to investigate the path integrated attenuation (PIA) derived from the data product 2A25 of the precipitation radar (PR) onboard the Tropical Rainfall Measuring Mission (TRMM) satellite over a few tropical and extra-tropical locations in India. The authors have attempted, in particular, to find the functional relationships between the two, if any, and whether the functional relationship depends on season. The result of the investigation shows that the path integrated attenuation (PIA) mostly bears a linear relation with rainfall in every month over all the locations except over Bangalore in July. The relationship between the two does not exhibit significant variations. The paper presents the cumulative distribution of rainfall intensity and the path integrated attenuation (PIA). The article further investigates the probable factors, namely, the latitude and height of a location, elevation angle of the TRMM at the location, and rainfall affecting the path integrated attenuation (PIA). The investigation reveals that the PIA at any location can be estimated based on the rainfall, latitude, elevation, and height of the location.

Keywords-Tropical Rainfall Measuring Mission; rainfall; path integrated attenuation; TRMM elevation angle; tropical locations; precipitation radar