Study of geomagnetic storm induced acoustic gravity waves over equatorial latitude

An attempt has been made to study the influence of geomagnetic storm on the tropospheric acoustic gravity waves at equatorial station, Tirunelveli (8.7°N, 77.8°E), India. The daily average of the amplitude and phase of acoustic gravity waves has been studied for the period 2000-2004. Severe geomagnetic storms occurred during April and September 2000, April 2001, October and November 2003 and November 2004. It is found that geomagnetic storm influences the tropospheric acoustic gravity waves. There is a delay between the occurrence of geomagnetic storm and tropospheric acoustic gravity waves. The delay is a function of strength of the geomagnetic storm. Severe geomagnetic storm such as that of November 2004 shows a short-period delay of ~ 5 days, and strong geomagnetic storm like the one of July 2004 shows the long-period delay of about 15 days.