Atmospheric Gravity Wave Features Related to Stratospheric Moistening During Tropical Cyclones

Atmospheric gravity waves are generated by the interplay of earth's gravity and buoyancy effect on an air parcel. The zonal and meridional wind and temperature perturbations observed in the troposphere and stratosphere exhibit signature of gravity waves. These gravity waves can originate from different excitation mechanisms such as deep convection in the tropics, orographic effects and various meteorological disturbances. We have studied the gravity wave generated due to an intense tropical cyclone named, Phailin, using radio occultation data from COSMIC over the Indian region. The radio occultation data are used to obtain the vertical profiles of atmospheric refractivity that bear the manifestation of gravity waves at different heights. The dry temperature and water vapor pressure from the refractivity profile yield the potential energy and the water vapor intrusion due to gravity waves in the lower stratosphere (18-25 km) during the tropical cyclone.