Long-term variability in the mesospheric tidal winds observed by MF radar over Tirunelveli (8.7N,77.8E)

Abstract

Observations of mesospheric tidal winds in the 84-98 km height range over a period of five years with the MF radar at Tirunelveli (8.7øN, 77.8øE), India, are presented in this study. The emphasis is on describing the long-term variability in the tidal amplitudes. The results reported herein clearly indicate pronounced interannual variability in the tidal activity, and strengthen the earlier suggestion that this feature is linked to the stratospheric quasi-biennial oscillation (QBO)