Hydrodynamic tropospheric wave sources and their role in gravity wave climatology of the upper atmosphere from the MU radar observations

The results of measurements of generation of internal gravity waves (IGWs) in the troposphere by mesoscale dynamical processes with the MU radar are p resented. Zonal and meridional horizontal nonlinear advective accelerations are estimated using eight directions of the MU radar antenna beam. Seasona l variations of the intensity of tropospheric IGW sources are discussed usi ng the results of the observations in all seasons. A contribution of IGWs g enerated in the troposphere into dynamics of the mesosphere and lower therm osphere is considered by comparing the MU radar data with a theoretical mod el. Possible contribution of IGWs generated in the troposphere at middle an d equatorial latitudes to interannual variations of the wave intensity and general circulation of the middle and upper atmosphere over the MU radar is discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.