LOWER STRATOSPHERE COUPLING WITH THE MESOSPHERE THROUGH THE QBO

Long term variations of 2-3 yr in ionospheric absorption data observed at 2.132MHz over Delhi (28.6 degrees N, 77.2 degrees E) were investig ated. The association of this oscillation with that of the stratospher ic quasi-biennial oscillation (QBO) in wind data, was examined. The an ti-correlation coefficient between the QBO in radio absorption data in the lower ionosphere and wind data at 28 km altitude was found to be 0.8, significant at the 99% confidence level. One of the causes of the presence of the QBO in absorption data seems to be controlled by the QBO in lower stratosphere winds. (C) 1997 Elsevier Science Ltd.