资源环境科技发展态势分析平台

We 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) of PFs in 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 minimum PCTs than Pacific Ocean MCSs. Pacific Ocean MCSs had higher rainfall rates, however, than Caribbean Sea MCSs. Despite the fact that MCSs represented <1% of the total precipitation systems found, the MCSs contributed more rainfall over the study regions. Over the Pacific Ocean, for example, MCSs contributed approximately 57% of the total rainfall contributed by all precipitation systems identified over that region. Additionally, MCSs over 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 degrees W. The annual cycle of PFs showed a marked bimodal annual cycle over Colombia, whereas over the Amazon Basin, Pacific Ocean, and Caribbean Sea, PFs were characterized by a unimodal annual cycle.