The season peculiarities of behaviour of the long-term temperature trends in the middle atmosphere on the mid-latitudes

• Published in: Physics and chemistry of the earth. Parts A/B/C 2002, Vol.27 (6), p.529-534
• Main Authors: Semenov, A.I, Shefov, N.N, Lysenko, E.V, Givishvili, G.V, Tikhonov, A.V
• Format: Article
• Language: English
• ISSN: 1474-7065; 1873-5193
• DOI: 10.1016/S1474-7065(02)00034-7

On the basis of rocket, nightglow and radiophysical measurements at heights of 25–110 km in middle latitudes the seasonal variations of the long-term temperature trends at various altitude levels are determined. At heights of 25–87 km the trends are mainly negative within all year. Only in winter period in middle and upper stratosphere the trend within several months becomes positive. At heights of 92–93 km the trend is very close to zero throughout the year. In summer period the altitude of zero trend extends downward to heights of 82–85 km, where the noctilucent clouds are usually observed. At heights of 95–110 km the trends are positive all year round. Mean annual height distribution of the temperature trend shows long-term cooling at atmospheric heights between 25 and 90 km, leading to a systematic subsidence of the upper atmospheric layers.