Spatiotemporal structures of rainfall over the Amazon basin derived from TRMM data

Abstract

On the basis of Tropical Rainfall Measuring Mission (TRMM) daily accumulated rainfall data (3B42 v7 product) covering 16 years (1998-2013), the Amazon Basin (AB) time and space rainfall variability is analysed. Different behaviours of precipitation over AB are found to the north and south of 8°S when the longitudinal band 70°-50°W is considered. The sample is then split into northern and southern sectors with respect to 8°S, describing their monthly evolution as a function of longitude. The main spatial oscillation modes are isolated and analysed through continuous wavelet transform analysis. Intense spatial oscillations are found close to the western side of the studied region. Several temporal modes in different scales are detected within each sample. Two of them show scales longer than 12 months, which are probably associated with ENSO phases. Smaller scale oscillations, evaluated from daily data, are also found. The northern sector of AB shows more daily data variability than the southern one and seems to be more affected by large temporal processes than the southern sector.