Caracterização da formação de nevoeiros sem precipitação em Santa Maria, RS, no período de 2003 a 2013

Abstract

The Rio Grande do Sul Central Region is important for many activities in this State. High fog occurence is the characteristic of this particular region in Southern Of Brazil. Fog is directly associated with liquid water content in the atmosphere nearby surface. In this way, fog phenomenom can be originated by surface radiative cooling by the longwave emission in land areas or by the moist air mass advection over the cold surface, for exemple inshore areas. Furthermore, fogs can be form associated with cold frontal passage. The main goal of this work is characterize the fog occurence in the Central Region of Rio Grande do Sul. To accomplish this task METAR (Meteorological Aerodrome Report) was applied to select fog events. This data are provide by REDEMET. The fog cases was grouped in precipitation and noprecipitation events. To descrive the conditions synoptic Final Analysis (FNL National Centers for Environmetal Prediction) data was employed. The results shown que noprecipitaion fogs are most commun than precipitaion fogs between 09-14 UTC. Moreover, fog events are frequently in autumn and winter seasons, while precipitaions are uniformly distributed over the year in the fog of events with precipitation. Related to synoptic conditions, fog associated to anticyclones are 62% about noprecipitaions events, with highoressure center posicioned at east of Santa maria.