Abstract
This paper aims at investigating some wind and moisture anomalies in August in the Sahelian drought of the early 1980's. The 1982-1984 drought is characterized by the excessive decrease in precipitation (in 1982-1983) and the southward retreat of the rainbelt (in 1984) along 0° meridian, and by the simultaneous southward retreat of the rainbelt (especially in 1984) along 35°E meridian. The mid- and upper-tropospheric easterlies at Niamey was greatly intensified in 1982 and this situation continued until 1984. The intensification of upper-tropospheric easterlies is not found in the previous (1968-1973) drought. In 1984, the surface dew point depression (T-Td) for Niamey rose rapidly to its maximum for the period 1964-1984, thus suggesting an abrupt decrease in the water vapor supply from the Golf of Guinea. The surface dew point depression (T-Td) for Khartoum also roser apidly in 1983 and reached its maximum in 1984 when rain-bearing equatorial westerlies were abnormally below 850 mb. At Khartoum, westerlies appeared abnormally at 300-500 mb and 700 mb in 1983 and 1984, respectively.
