Assessment of satellite precipitation estimates over the slopes of the subtropical Andes

RENE GARREAUD; PAOLA SALIO; DANIEL VILA; MARÍA PAULA HOBOUCHIAN; YANINA GARCÍA SKABAR

ATMOSPHERIC RESEARCH

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2017 p. 43 - 54

0169-8095

A validation of four satellite daily precipitation estimates at a spatial resolution of 0.25° is performed over the subtropicalAndes, an area of highly complex topography: The Tropical Rainfall Measuring Mission (TRMM)Multisatellite Precipitation Analysis (TMPA, 3B42 V7 and RT), the Climate Prediction Center Morphing technique(CMORPH) and the Hydro-Estimator (HYDRO). Remote mountainous regions represent a major challenge forthese satellite data products and for studies examining their quality with surface data.For the assessment of the satellite products, a period of seven years fromJanuary 1st 2004 to December 31st 2010was considered. Different statistics were analyzed considering their variability in the study area and identifyingtheir main differences between thewarmand cold seasons. The results indicate a decrease inwinter errorswhichcoincideswith thewet season over thewindward side of the Andes. Also, a significant underestimation of precipitationis observed for all estimates throughout the period analyzed.The analysis with respect to terrain height shows a greater dependence of errors with topography for all the algorithmsthat combine infrared and passive microwave data, HYDRO providing the most stable result. The mainlimitations of the estimates associated with the type of precipitating event and their location relative to the orographyare assessed.Finally, the analysis of two intense precipitation events is presented and allows the assessment of the latest advancesin satellite derived estimates with the launch of the Global Precipitation Measurement.