Teleconnections and Sea Surface Temperature Anomaly Effects on the Drought of 1983 in Northeast Brazil

摘要

The year 1983 was an year of extreme drought in the Northeast Brazil (NEB). The 1983 precipitation in NEB in its rainy season was observed to be only 40% of the normal by Rao and De Brito (1984). The Newfoundland monthly mean surface pressure anomalies showed values ranging from +2 to +4 mb during the period October 1982 April 1983. These support the teleconnections between the NEB precipitation and the low level cyclonic activity in the region of Newfoundland proposed by Namias (1972). The difference between sea surface temperature anomalies north of the equator and south of the equator in the Atlantic is considered as an index to verify the effect of north-south Hadley circulation on the NEB drought as proposed by Moura and Shukla (1981). During the months of December January and February the anomaly is less than 1 C and during March, April, and May it is even slightly negative. This shows the drought of 1983 was not due to the changes in the north-south circulations and suggests the relative importance of anomalous east-west Walker circulations, as caused by El Nino, for example.