Analysis of TRMM Rainfall and Lightning Measurements in Chile during the Summer of 1997/98 (El Niño) And 1998/99 (La Niña) Summer Events

The Tropical Rainfall Measuring Mission (TRMM) is a joint program between United States and Japan through their respectively space agencies, NASA and NASDA. This project aims to understand the precipitation and the liberation of latent heat process over the tropics. Therefore, instruments such as precipitation radar, lightning and microwave imagers and visible and infra-red sensor are onboard the TRMM satellite. Its orbit is constrained between 35N-35S latitude belts and is operational since 30th November, 1997.

Since its beginning, TRMM has been able to measure rainfall and lightning over the tropics during El Niño and La Niña episode years. Preliminary analysis of monthly rainfall and lightning accumulation in Chile (12°S to 35°S ) shows a minimum over the Andes Mountain of Chile during the 1997/1998 El Niño summer year. This has been followed by an increase of electrical discharges during the La Niña episode of summer 1998/1999. This paper will make a detail analysis of these measurements to understand the physical and dynamical mechanisms linked between the precipitation and lightning. Afterwards, a statistical analysis of the precipitating and non-precipitating systems, the classification of convective and stratiform rainfall, and finally their association with electrical discharges will be performed over the region of Chile.