The characteristics of clouds and precipitation over the Pacific coast of southern Mexico retrieved from satellite TRMM products

Mexico is characterized by a variety of climates, from extreme desert conditions in the Northwest region to tropical jungle in the Southern states (between 150 and 180 N). Moreover, these latter regions that climatologically receive over 1500 mm annual average of accumulated precipitation, are located in very rugged terrain, with mountains ranges reaching 3000m amsl, less than 100km from the coasts, enhancing the potential of orographic precipitation and are very susceptible to flooding and landslides.

The purpose of this study is to evaluate the vulnerability of the Pacific coast of southern Mexico to intense precipitation events. A complementary study has indicated that these intense events are linked to easterly waves passing over the region, tropical cyclogenesis in the Gulf of Tehuantepec or other variability in the Inter-Tropical Convergence Zone.

The Tropical Rainfall Measuring Mission (TRMM) satellite products for the period 1998-2009 are used to characterize vertical profiles of clouds and precipitation over the studied area. Spatial and temporal variations in precipitation intensity are analyzed in order to identify the most vulnerable regions and periods when the strongest precipitation events are observed. The average diurnal variations in precipitation and vertical cloud development over ocean and ground are evaluated for every month. The data from the Lightning Imaging Sensor in TRMM are also used to identify the areas with highest concentrations of total lightning and their temporal variabilities and compared with observations from the World Wide Lightning Location Network (WWLLN) already analyzed in a previous study for the region from 2004 to the present.