IDENTIFICAÇÃO DE SECAS METEOROLÓGICAS NA REGIÃO METROPOLITANA DE FORTALEZA, USANDO O ÍNDICE DE PRECIPITAÇÃO PADRONIZADA (SPI).

The Metropolitan Region of Fortaleza is composed of fourteen municipalities grouped into two micro-regions: the micro-region of Fortaleza and Pacajus. The regions are located in the Northeast of Brazil, State of Ceara. Are under the control of semiarid climate and are marked by cyclical occurrence of droughts. The aim of this paper is detect the occurrence of years of meteorological droughts in the Metropolitan Region of Fortaleza, between the years 1974-2012, using the index SPI (Standardized Precipitation Index) on the timescale of four months (Feb / May). The episodes of droughts detected by SPI were correlated with the occurrence of large-scale atmospheric events that operate in the Brazilian Northeast, for example: El Niño Tropical Atlantic Dipole and the position of the ZCIT (Intertropical Convergence Zone). Thus, the study found that almost all dry years detected by the index SPI were years of El Niño events, along with the meridional gradient of TSM anomalies, that associated, commands the incursion of the ZCIT over the equator, influencing distribution of rain over the Northeast. The study also found that major droughts in the study area have been moderate and severe category. [ABSTRACT FROM AUTHOR]