Na lidar Investigation of gravity wave forcing and its effects on tidal variability in mesopause region by nocturnal zonal momentum flux measurement and full-diurnal cycle lidar observations at Logan, UT (42N, 118W)

Gravity wave forcing (GWF) is induced by the momentum deposition during the wave breaking event. It is believed to be the major dynamic source in the mesosphere and lower thermosphere (MLT) that affects not only the global climatological features but also the mesoscale events in this region. The Utah State University (USU) Na Doppler Temperature/Wind lidar set up zonal co-planner beam in June 2011 to measure the zonal momentum flux through zonal wind variance calculations. Meanwhile, the lidar's multi-day continuous full diurnal cycle observations provide opportunity to investigate the GWF on the tidal wave variability and propagations within the mesopause region. In this paper, we are going to discuss the nocturnal GWF revealed by the lidar momentum flux measurements in one collaborative continuous 5-day campaign with Advance Mesospheric Temperature Mapper (AMTM) at USU and the Meteor Wind Radar at Bear Lake Observatory (BLO) in August 2011. The AMTM also captured one intensive mesospheric "Bore" event during one night with strong GWF, while TIMED/SABER data indicates that the temperature inversion layer (thermal duct region for "Bore" propagation) is well over 1000 km in horizontal scale, extending beyond west coast of North America. The correlation between zonal GWF and tidal wave will be investigated, along with planetary wave behavior through this campaign.