Seasonal features in the response of the mesopause temperature and emission intensities to solar activity variations

The seasonal dependences of the response of the hydroxyl ((6–2) band) and molecular oxygen O₂(b ¹Σ _g ⁺ ) ((0–1) band) emission intensities, temperature, and density indicator in the region of the hydroxyl emission maximum (87 km) to solar activity have been obtained based on the spectral observations of the mesopause emissions at Zvenigorod observatory during 2000–2007. The ratio of the OH (7–3) and (9–4) band intensities, characterizing the behavior of the vibrational temperature, has been used as an indicator of density. It has been established that the response of the studied mesopause characteristics to solar activity is positive in all seasons. In winter the response is maximal in the intensities and temperature and is minimal in the density indicator. The main mechanisms by which solar activity affects the mesopause characteristics have been considered. The behavior of the internal gravity waves with periods of 0.33–7 h depending on solar activity has been studied. It has been noted that these waves become more active at a minimum of the 11-year solar cycle.     

Spatial and temporal variations in infrared emissions of the upper atmosphere. 2. 15-μm carbon dioxide emission

The results of rocket and satellite measurements of carbon dioxide emissions at a wavelength of 15 μm in the upper atmosphere have been systematized and analyzed. Analytical expressions describing the dependence of the altitude distribution of 15-μm CO₂ emission intensity and its variation in the altitude range from 100 to 130 km on the season, latitude, and solar activity have been obtained.     

Satellite-based analysis of the spatial patterns of fire- and storm-related forest disturbances in the Ural region,Russia

Natural Hazards - Large-scale wildfires and windstorms are the most important disturbance agents for the Russian boreal forests. The paper presents an assessment of fire-related and wind-induced...     

Spatial and Temporal Variations of Infrared Emissions in the Upper Atmosphere. 3. 5.3-μm Nitric Oxide Emission

The results of rocket and satellite measurements available in the literature of 5.3-μm nitric oxide emission in the upper atmosphere have been systematized and analyzed. Analytical dependences describing the height distribution of volumetric intensity of 5.3-μm emission of the NO molecule and its variations in a range of heights from 100 to 130 km as a function of the time of year, day, latitude, and solar activity have been obtained.     

The behavior of emissions and temperature of the mesopause during stratospheric warmings according to observations at midlatitudes

Regularities in variations in the intensity of hydroxyl radiation (the (6–2) λ834.4-nm band) and the Atmospheric system of molecular oxygen (the A(0–1) λ864.5-nm band) of the mesopause, hydroxyl temperature, and its night variability during sudden winter warmings of the stratosphere have been obtained based on long-term observations in Zvenigorod.     

Empirical model of variations in the emission of the molecular oxygen Atmospheric system. 2. Temperature

The empirical approximations of variations in the rotational temperature of the emission of the molecular oxygen Atmospheric system, obtained based on the systematization of the long-term ground-based observations under different heliogeophysical conditions, are presented.     

Lunar Tides in the Mesopause Region Obtained from Summer Temperature of the Hydroxyl Emission Layer

Geomagnetism and Aeronomy - The summer mesopause region (altitudes of 82–92 km) is the coldest place in the Earth’s atmosphere; it is influenced by external effects, including lunar...     

Seasonal temperature variations near the mesopause according to the hydroxyl emission measurements in Zvenigorod

The rotational temperatures of hydroxyl molecules with different vibrational excitation, which were used to determine the seasonal variations in the vertical temperature distribution near the mesopause at altitudes of 85–90 km, have been obtained based on the spectral measurements of the atmospheric nightglow at IFA RAN observatory in Zvenigorod. The obtained characteristics of the annual and semiannual harmonics have been compared with their lidar and satellite measurements and model representations.     

Ground-based observations of noctilucent clouds with a northern hemisphere network of automatic digital cameras

For the first time we present an analysis of observations of noctilucent clouds obtained with a network of automatic digital cameras located at opposite sides of the northern hemisphere. The advantage of this network is that the cameras are located along the same latitude circle producing comparable measurements. We find that there is an indication of the 2-day planetary wave propagation influencing the occurrence frequency, geographical distribution and brightness variations of noctilucent clouds. The 5-day planetary wave has much less effect on noctilucent clouds than that of the 2-day wave, at least for the summers of 2006 and 2007. At the same time, bright noctilucent clouds tend to occur every successive night during short periods of 3–5 nights.