Estimativa da variabilidade interanual do balanço de umidade das bacias Amazônica e do Prata.

Abstract

This work presents an estimate of the interannual variability of the balance of of the Amazon and La Plata Basins during the period from 1979 to 2016 using ERA-Interim reanalysis data from the European Center for Medium-Range Weather Forecasts (ECMW). For this analysis, a method was used to estimate the flow of vertically integrated moisture from three control volumes known as boxes, delimited by the following coordinates: a) Box 1 (3°N to 14°S, 70°W to 50°W) representing the Amazon Basin (Brazilian part), b) Box 2 (14°S to 24°S, 65°W to 45°W) including the Southeast and Central-West Region of Brazil, Central-Eastern Bolivia and north-central part of Paraguay and c) Box 3 (24°S to 34°S, 65°W to 47°W) representing the Southern Region of Brazil, Southern Paraguay, Northern Argentina and Uruguay. with respect to Amazon and La Plata Basins, the results showed that, on an annual average, the basins behave as a sink for atmospheric moisture, in addition, the Amazon Basin is a source of moisture for the La Plata Basin. Regarding the transport of moisture, the results revealed that box 1 receives 16.6% of the moisture flow by trade winds Northeast by the northern border from the North Atlantic Ocean and 83.4% by the eastern border of the South Atlantic Ocean by the east/northeast trades. box 2 receives Amazonian humidity along the northern (63.2%) and western (27.6%) border and the Atlantic Ocean South contributes directly with 9.2% (9.1% for the eastern border and 0.1% for the south). in the total of box 3 moisture, approximately 88.2, 10.3, 1.1 and 0.4% come from the northern, western, eastern and southern borders, respectively, the profiles verticals of the product of the specific humidity by the wind component to verify the behavior across the 23 pressure levels. The analysis of the variability of the transport of moisture over the regions of the Amazon and La Plata Basins revealed that much of the moisture that reaches the La Plata Basin comes mainly from the Amazon. However, from the contribution of precipitation recycling, the percentages of 54, 69 and 49% for boxes 1, 2 and 3, respectively.