Mesoscale convective systems and other precipitation features over the tropical Americas and surrounding seas as seen byTRMM

Abstract

ABSTRACTWe classified and characterized precipitation features (PFs) at annual and diurnal timescales during 1998–2011 over the tropical Americas and adjoining oceans using data from two instruments on board the Tropical Rainfall Measuring Mission (TRMM). Our scope included geographic distribution, frequency, area, rainfall rate, and polarization‐corrected temperatures (PCTs) ofPFsin an effort to contrast different regions over Colombia, the Amazon River Basin, and the adjoining oceanic regions (Pacific Ocean and Caribbean Sea). Our results showed that mesoscale convective systems (MCSs) over the Caribbean Sea exhibited colder minimumPCTsthan Pacific OceanMCSs. Pacific OceanMCSshad higher rainfall rates, however, than Caribbean SeaMCSs. Despite the fact thatMCSsrepresented <1% of the total precipitation systems found, theMCSscontributed more rainfall over the study regions. Over the Pacific Ocean, for example,MCSscontributed approximately 57% of the total rainfall contributed by all precipitation systems identified over that region. Additionally,MCSsover the Pacific coast have their maximum frequency during the morning hours (0000–0600 Local Time) offshore and centred over the Pacific Ocean at 77.5°W. The annual cycle ofPFsshowed a marked bimodal annual cycle over Colombia, whereas over the Amazon Basin, Pacific Ocean, and Caribbean Sea,PFswere characterized by a unimodal annual cycle.