Climatological patterns over South America derived from COSMIC radio occultation data

Abstract

Meteorological phenomena are closely linked to the presence of water vapor. They are mainly originated and developed in the troposphere, where almost all the atmospheric water is concentrated. The Global Positioning System Radio Occultation (GPS RO) technique provides vertical pro les of atmospheric properties such as refractivity, from which temperature and water vapor are derived. The GPS RO capability to reproduce global, and synoptic and regional climatological patterns over South America, which is a mostly oceanic continent, is tested. From FORMOSAT-3/COSMIC mission data (2006- 12 2010), our previous knowledge regarding global and synoptic/regional patterns of temperature, equivalent potential temperature, specific humidity and pressure is verified. Special cases such as baroclinic disturbances arriving at South America midlatitudes and storm events over a mountain region near the Andes are analyzed. The temporal evolution and the latitude-longitude distribution in several layers of the variables listed above are well described with this technique. Water vapor is one of the most important variables in the troposphere because of its infuence in the energy transport and circulation within the Earth weather and climate system through latent heat exchange. Besides, it is the most important greenhouse gas in the atmosphere. Water vapor largely affects the radiative balance of the Earth surface and the extent and type of the continental biosphere.