Abnormal modulation of atmospheric parameters during the tsunami of 2004

摘要

This paper discusses the abnormal changes in weather elements observed at a tropical mountain location and a coastal station in India. Abnormal changes were noticed in the atmospheric parameters at a time close to the occurrence of tsunami on the Indian coasts due to high magnitude earthquakes in the Sumatra region on 26 December 2004. Close to the time of this earthquake occurrence, uncharacteristic and large magnitude changes in weather elements were recorded at Braemore (8 degrees 45'N, 77 degrees 05'E, 360 m amsl), a mountain field station at Western Ghats. Abnormal changes were also recorded at Minambakkam (13 degrees N, 80 degrees 18'E, 16 m SLP), close to eastern coastal belts. In the Braemore field station, simultaneous changes were observed in the atmospheric parameters; decrease in pressure by 0.6 hPa, increase in relative humidity by 30% and a prominent reduction in air temperature by more than 3 degrees C on the day of tsunami. Also, unusually the relative humidity did not reach 100% on the previous night. However, in the Minambakkam station, the relative humidity increased by 10% associated with a sharp decrease in temperature by about 2.5 degrees C. The changes in both the stations occurred almost at the same time and duration. Therefore, it may be concluded that these changes are associated with the high magnitude earthquake and subsequent tsunami.