Aspectos climáticos das posições da zona de convergência intertropical e dos anticiclones semipermanentes do Atlântico Sul e do Pacífico Sul: relações com regimes de chuva no nordeste do Brasil.

Abstract

The present research aimed to analyze the influence of the positioning of the Intertropical Convergence Zone and the Semi - Permanent Altitudes of the South Atlantic and South Pacific in the precipitation over the Northeast region of Brazil using NCEP reanalysis data. For the development of this work, data of the uev component of the wind velocity were used, and then the vorticity was calculated to acquire the climatological series of each meteorological system (ZCIT, ASAS and ASPS) in the period from January 1988 to December 2017. In addition, we obtained the precipitation climatological series using the reanalysis data available in the Global Precipitation Climatology Project (GPCP) for three NEB regions: north, southwest and east coast. The first results refer to the monthly climatology of the precipitation of these three NEB regions and the positioning of meteorological systems. Precipitation climatology, in almost all regions, was similar for the rainy season and less rainfall was well defined, except for the coastal region. The climatology of the average position of the ITCZ in which its southernmost position was identified in the months of January to May of the Southern Hemisphere, the month of March with the largest latitudinal displacement being approximately 6 ° S. The latitudinal variation of ASAS and ASPS are directly linked to seasonality. In the summer months the southernmost position of both semipermanent highs is verified, the opposite is also observed, with the northernmost positioning in the winter months. Longitudinal variation did not show a behavior dependent on the seasons of the year. However, it presented a great variability of its longitudinal position, mainly ASPS. ASAS obtained the easternmost position (around 5 ° L) in the months of March to May. Statistical analysis to determine the relationship between the ZCIT, ASAS and ASPS positioning with the precipitation of each region, re-² values of 0.85 and 0.72 were observed for the northern region, 0.61 and 0.37 for southwestern region and 0.41 and 0.16 for the eastern coastal region, showing that from all regions, the northern part of the NEB has a stronger relationship with the ZCIT, ASAS and ASPS positions.