Gravity Waves (GWs) play an important role in both the formation and destruction of polar mesospheric clouds (PMCs). In this study we investigate the possible effect of GWs generated over the monsoon region on PMCs, during the northern hemisphere 2007 PMC season. We use temperature data from the SABER instrument on the TIMED satellite, wind data from the high resolution NOGAPS ALPHA model, and PMC frequency of occurrence from the CIPS instrument on the AIM satellite. The NH GW momentum flux calculated from SABER temperature perturbations shows a poleward tilt with increasing altitude. This poleward tilt is also seen in the GW momentum flux calculated from the NOGAPS-ALPHA model results. The latitudinal shift in GWs is possible owing to the slanted structure of the summer easterly winds that can focus the low latitude GWs into its jet, thus suggesting a poleward but non-vertical propagation of GWs from the low altitude tropics to the high altitude poles. We find a significant positive correlation between the GWs over the monsoon region at 50 km and PMC frequency of occurrence over the polar region at 84 km suggesting a possible source of high latitude middle atmospheric GWs that can influence PMCs.

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*email: brenthat@vt.edu
*Preference: Oral