Climatology of mesospheric gravity wave activity over Urbana, Illinois (40°N, 88°W)

Gravity wave activity in the mesopause region from airglow measurements at El Leoncito

“…However, some details are di erent, and none of these other observations refers to the South American sector. The strong presence of the semiannual variation at 95 km distinguishes our results from those obtained at Urbana (40 • N; Thorsen and Franke, 1998), where it nearly disappears above 90 km.…”

“…Gravity wave activity is expected to be a highly local phenomenon, strongly controlled by the geographical distribution of sources. In the mesopause region, most of the reports have been based on radar wind data (e.g., Vincent and Fritts, 1987;Thorsen and Franke, 1998;Manson et al, 2002) or lidar-derived density and wind data (e.g., Senft and Gardner, 1991). The use of mesopause region temperature data has been limited to studies of short duration.…”

Gravity waves in the mesopause region observed by meteor radar, 2: Climatologies of gravity waves in the Antarctic and Arctic

“…However, the observed growth is always at a rate substantially less than the exponential increase that would be predicted for the unconstrained growth of vertically propagating waves. A similar behaviour has been reported in other observations of gravity waves from a range of latitudes (e.g., Vincent and Fritts, 1987;Vincent, 1994;Thorsen and Franke, 1998;Dowdy et al, 2007).…”

Trends of mesospheric gravity waves at northern middle latitudes during summer

“…To understand physical processes responsible for long-term changes in the MLT it is essential to know their relations to long-term changes of GWs. While most long-term observations of GW were used to estimate averaged mean annual cycles [e.g., Thorsen and Franke, 1998;Hibbins et al, 2007;Rauthe et al, 2008;Beldon and Mitchell, 2009;Placke et al, 2011] there are only a few studies on the climatology of GWs in the MLT over a longer time period where the data have been analyzed for trends. One of the first studies is based on 14 years of wind data derived from observations with the MF radar at Saskatoon (52°N, 107°W) [Gavrilov et al, 1995] where the mean seasonal variation of the GW intensity for different periods and their correlation with both solar and geomagnetic activity have been investigated.…”