CHANGES IN THE STRATOSPHERIC AND MESOSPHE RIC THERMAL CONDITIONS DURING THE LAST 3 DECADES .2. THE EVOLUTION OF A TEMPERATURE TREND

Moving estimates of a 13-year temperature trend were derived in the he ight range of 25 to 75 km from monthly mean temperatures measured by r ocket sounding over Hayes Island, Volgograd, Tumba, and Molodezhnaya s tations during 1964-1994. A negative trend of upper and middle mesosph eric temperatures was shown to have increased since the early 1970s, b ut its magnitudes have been progressively decreasing since the first h alf of the 1980s. A stratospheric and lower mesospheric negative trend was shown to have been decreasing since the start of observations and reached positive magnitudes in recent years. The results obtained wer e compared with trend estimates based on satellite, lidar, radiophysic al, and optical observations, as well as with data from the US rockets onde network.