Estimating Gravity Wave Momentum Flux from Airglow Images

Estimating gravity wave momentum flux from all-sky airglow images independent of high-resolution lidar/radar wind measurement is highly demanded for seasonal and geographical study of gravity waves in the mesopause region. A novel technique has been developed for extracting the vertical fluxes of horizontal momentum of high frequency gravity waves with airglow images and background lidar/radar winds. This approach identifies monochromatic wave components and extracts intrinsic wave parameters from Doppler corrected time differenced (TD) images. With momentum fluxes calculated for all the wave components from each TD image in one night, the statistical momentum flux value is estimated. This technique has been applied to OH data collected in 2002 at Maui, Hawaii and validated by comparing the daily results with the momentum fluxes extracted from temperature data collected by Na lidar that was operating simultaneously. Seasonal variations of high frequency wave propagation derived from all-sky images will be compared with low frequency wave directions acquired from lidar wind measurement using hodograph method.