Seasonal Variation in Gravity Wave Momentum and Heat Fluxes in the Mesopause Region Observed by Sodium Lidar

The seasonal variations in gravity wave (GW) vertical fluxes of zonal momentum and heat the mesopause region are calculated using nearly 10 years (from 2012 to 2021) temperature wind observations by a narrowband sodium lidar located Hefei, China (32°N, 117°E). Except summer, GW mostly westward, with ∼80% contributed short-period (10 min–1 hr) GWs, anticorrelate eastward wind. mean westward spring winter −2.55 −1.78 m2/s2, respectively, which much stronger than −0.98 m2/s2 fall. flux summer is primarily eastward, dominated long-period (1–16 GWs. These mainly due filtering GWs background at lower altitudes. annual value −1.08 m2/s2. acceleration from divergence below 93 km, opposite 94 km downward throughout year, no apparent variation. downward, cooling rate ∼−35 K/day between 87 95 km.