Aspectos climáticos da reciclagem do vapor d'água sobre o Brasil.

Abstract

In this study we investigated climatic aspects of the water vapor recycling on Brazil. Water vapor recycling refers to the feedback mechanism of the Land-Atmosphere system in which a certain fraction of water evaporated at a region falls again as precipitation at the same region. To evaluate these climatic aspects we studied the fields of the water vapor flow, evapotranspiration and precipitation in four terms (February-April, May-July, August-October, November-January) using 15 years of reanalisys of NCEP/NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research). We also analyzed monthly average values of the water vapor recycling in three areas of equal sizes (15° of latitude for 15 ° of longitude) in Brazil using 40 years of reanalysis of NCEP/NCAR. The results revealed recycling relatively low in the North and North-East regions, where the water vapor flow is more intense. However, the results revealed a transportation of water vapor from the Northern region to the Center-West, South-East and South regions. About the Center-West, South-East and South regions, where the water vapor flow is less intense, the water vapor recycling is more significant. The climatological aspects of the recycling of the water vapor on Brazil indicate that the processes advectivos are more important in the precipitation on the Northern and North- East regions, while in the Center-West, Southeast and South regions, the local processes have important paper in the precipitation. The results evidence that the water vapor recycling quantification is an indicator of the importance of the land-surface process to the hydrological cycle and it is, as well, an indicator of the climatic sensitivity.