Interaction of air non-stationary stream of the atmosphere with obstacles on an Earth’s terrestrial surface causes disturbances which are a source of various wave processes. Research of such processes and their influence on the upper atmosphere temperature regime carried out in 1985-1995 at Kislovodsk high-mountainous scientific station of the IAP RAS by measuring the mesopause temperature in the northern leeward area of the Caucasian ridge. On the data of the spectrophotometric measurements of the upper atmosphere hydroxyl emission characteristics, some information about the orographic disturbances at the mesopause altitudes and features of their generation in the surface atmosphere was obtained. It was found that the atmospheric temperature at altitudes around 90 km in the lee of mountains increased by 10 K (the mean value is about 200 K) at a distance of about 150 km from the ridge. The length of the disturbed region in the lee area is about 300 km. It is shown that the sources of wave disturbances are concentrated near the mountainous irregularities of the Caucasian ridge. These sources appear in the troposphere at altitudes of about 4 km. The process of generating waves with periods from 7 to 20 minutes is caused by wind gusts. Development of the theory of temperature disturbances in the lee of the mesopause has identified a number of new previously unknown features of the generation of internal gravity waves in the surface atmosphere. It was found, that the distribution of azimuths of fluctuations in the direction of local winds and wind gusts in the troposphere, causing the generation of waves, is described by the Henyey-Greenstein function with the same parameters of this function. On basis of the developed theory, the spatial distribution of energy flow in the lee of the mountains was calculated, its value is about 3 erg cm-2 s-1. The work is supported by the 10-05-00062 RFBR Grant.