Tendencies for changes in the parameters of winds in the midlatitude lowerthermosphere (90-100 km) as inferred from long-term wind measurements

The data obtained with the meteor radar at the Obninsk station from 1964 to 1995 are analyzed. The Long-term behavior of the annual mean zonal and mer idional winds and of the parameters of annual and semiannual variations are characterized by a clearly defined tendency for a decrease in the annual m ean winds and in the amplitudes of annual and semiannual wind variations in the period of time under consideration. A statistically significant negati ve (positive) correlation is established between the winter (summer) mean v elocities of the prevailing zonal (meridional) wind and the Wolf sunspot nu mbers. The relationship between the observed trends of the prevailing wind and independent estimates of long-period variations in other atmospheric pa rameters is discussed.