HR: 09:45h
AN: A51C-07    [PDF]
TI: Interaction Between Troposphere And Lower Stratosphere Associated With The Passage Of A Tropical Cyclone Over India
AU: * GOVINDANKUTTY, M
EM: mrudula@cusat.ac.in
AF: Department of Atmospheric Sciences, Lakeside Campus, Cochin University of Science and Technology, Fine Arts Avenue, Cochin -16, Kerala, India, Cochin, 682016 India
AU: Kumar, M
EM: kmk@md3.vsnl.net.in
AF: Department of Atmospheric Sciences, Lakeside Campus, Cochin University of Science and Technology, Fine Arts Avenue, Cochin -16, Kerala, India, Cochin, 682016 India
AB: Changes in the characteristics of the troposphere and lower stratosphere associated with the passage of a tropical cyclone has been studied using MST radar observations at Gadanki (13.5$^{0}$N, 79.2$^{0}$E), India. A tropical cyclone formed as a low pressure on 14th October 2001 in the west central Bay of Bengal developed into a deep depression by 15th October morning. This system intensified into a cyclonic storm on the same day evening, crossed over Gadanki on 16th October morning. In addition to the regular daily MST radar observations at 0930 hrs, special observations of 1-hour interval for 32 hours and 4-minute interval continuous observation during the time of cyclone over the station have been utilized for the study. The horizontal wind velocity components show considerable changes in the upper troposphere and lower stratosphere during the passage of the cyclonic storm, whereas the vertical wind show significant changes at 10 - 12 km level. The upper troposphere experiences strong northeasterly wind components during the passage of the cyclonic storm over the station. In lower levels, the magnitude of the wind speed is quite low, but the wind direction changes from northeasterly to southwesterly. After the passage of the cyclonic storm upper tropospheric wind speed reduces considerably, whereas the mid-tropospheric wind speed increases. In order to understand the dynamical interaction between the troposphere and lower stratosphere associated with the passage of the cyclonic storm, the zonal and meridional momentum flux transport in the vertical has been carried out. Considerable changes in the flux transport is noted in the upper troposphere and lower stratosphere.
DE: 3314 Convective processes
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3362 Stratosphere/troposphere interactions
DE: 3374 Tropical meteorology
DE: 3399 General or miscellaneous
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting