Statistical characteristics of atmospheric gravity wave in the mesopause region observed with a sodium lidar at Beijing, China

Nightly and seasonal variations of atmospheric gravity wave (AGW) activity in the sodium layer are investigated by analyzing 253 nights of sodium lidar observations. These observations were made from April 2010 to September 2011 at Yanqing, Beijing (40.3°N,116.2°N). Vertical wavelengths, periods and phase velocities of 162 quasi-monochromatic AGWs are extracted from the lidar data. An average parameter relationship λz=0.212Tob0.544 is found. Nightly statistical results show that the activity of AGW has maximum from 22 to 24 LST in night. Monthly statistical results reveal that AGW activity maximizes in summer and minimizes in winter. Seasonal variation characteristic of AGW activity is interpreted based on a qualitative analysis of probable main sources in Northern China. Influences of seasonally varying temperature and background winds on AGW activity are discussed.