Temperature data of the mesopause region, obtained for the period 1999-2016 at the Maimaga station (63.04°N, 129.51°E), were studied. Registration of spectra was carried out with the help of light-sensitive infrared spectrographs SP-50, recording the OH (6-2) band. The standard deviation of temperature σpw from its average monthly value after deduction of seasonal temperature course is accepted as a characteristic of planetary wave activity. There is a quasi two-year cycle of planetary wave activity. A correlation is observed between the activity of planetary waves and the F10.7cm index.
The temperature data of the mesopause region obtained for the period 2013-2018 at the station Maimaga (63.04° N, 129.51° E) was investigated. During the winter period of the 2014–2015 observation season, the characteristic of the internal gravity waves (IGW) activity σgw has lower values than in other seasons, and the average night temperature of the mesopause region, on the contrary, exceeds corresponding values in other seasons. For comparison, satellite data of temperature profiles obtained by EOS MLS (Aura) are given. After isolating and subtracting the contribution of the gravitational component from the EOS MLS temperature profiles for the region above the Maimaga station, the difference in the winter stratopause of the 2014-2015 season is noticeable. During this season, the winter stratopause has lower temperatures than in other seasons, taking into account the deduction of the contribution of temperature fluctuations due to IGW.
Research of atmospheric gravitational waves on the observations of noctilucent clouds in the city of Yakutsk in the summer season of 2018 was carried out. The observations were made using a permanently installed Samsung Galaxy S4 / mini phone using the free program Time Lapse Creator. The shooting was carried out with an exposure of 2 seconds, every 2 minutes in the direction above the northern horizon. The rare case of observing such a wave structure of noctilucent clouds on July 26, when several waves of different lengths and intersecting directions of propagation are simultaneously observed, is analyzed. The main characteristics of the analysis of these gravitaty waves are given.
The temperature of the mesopause region (87 km) is monitored at the Maimaga station (63.04° N, 129.51° E) using the Shamrock (Andor) spectrograph recording the OH band (3, 1). The temperature data obtained for the seasons from 2013 to 2017 are investigated. Standard temperature deviations σgw corresponding to internal gravity waves are obtained. The seasonal variation of the gravitational component of standard deviations of temperature σgw observed at Maimaga station almost coincides for three observation seasons except for the 2014-2015 season. In this observation season, σgw has lower values in winter than in other seasons. In addition, in the 2014-2015 season, average monthly temperatures exceed similar values in other seasons.
A new infrared spectrograph with high temporal resolution for observation of OH band (3–1) emission dynamics is described. For the automated work of the spectrograph, special software was created. Remote control over the device is also configured.
Research of the seasonal change of mesopause temperature at height of nightglow of hydroxyl excited molecules and its correlation with geomagnetic activity during the 23 solar cycle is presented. An infrared digital spectrograph installed at the Maimaga station (63°N, 129.5°E) measured P-branches of the OH(6-2) band. The rotational temperature of OH emission (TOH) is assumed to be equal to the neutral atmosphere temperature at the altitude of ~87 km. The database of TOH comprises 2864 nightly average temperatures obtained from August 1999 to May 2015 is considered. The observation starts at the beginning of August and ends in the middle of May. It was revealed that the maximum flux of radio emission from the Sun with a wavelength of 10.7 cm is 2 years ahead of the maximum of seasonally averaged temperature. Temperature is correlated with a change of Ap-index which is a measure of geomagnetic activity. Nightly mean TOH were grouped in accordance with the geomagnetic activity level: the temperatures measured during years with a high activity (Ap> 8), and low activity (Ap <= 8). It was found that the mesopause temperature from October to February is higher by a factor of about ·10 K than during years with low activity (Ap <= 8). There is no dependence of the TOH on the level of geomagnetic activity in autumn and spring.
Dynamics of seasonal variations in the amplitude of the VLF radio signal received in Yakutsk from the navigation station near Novosibirsk and the radiation intensity in the wavelength range from 835 to 853 nm, where the P-branches of the OH band (6-2) are located, is present. The radiation variations give information about mesopause region measured at the Maimaga station (130 km from Yakutsk). Observation period from 2009 to 2015 covers period with minimum and maximum solar activity (solar flux F10.7). In the seasonal dynamics of the VLF amplitude signals and the mesopause temperature are observed annual, semiannual and third-annual variations, increasing during nighttime for VLF signals. The mesopause temperature and the VLF signal increase with increasing solar flux F10.7 in winter.
The report presents a comparison of the rotational temperatures of OH band (3, 1) at an altitude of about 87 km measured by two spectrographs installed at the optical stations: Maimaga (63.04 ° N, 129.51 ° E), which is located 120 kilometers north of Yakutsk and Tiksi (71.6 ° N, 128.7 ° E).
The analysis of changes in temperature of mesopause region based on fluctuation measurements of rotational temperature and intensity of molecular emission of hydroxyl OH (6,2) excited at ~87 km altitude is presented. Observations were carried out at the Maimaga station (63°N, 129.5°E), at a distance of 150 km to the north from Yakutsk. Parameters of seasonal variation was defined based on the data received from 1999 to 2015. Measurements were conducted with a digital infrared spectrograph. The temperature was determined from the distribution of the emission intensity in the different branches of the molecular hydroxyl band. Data from the radiometer SABER v.2.0 installed on the satellite NASA TIMED was used in the research. 2320 midnight temperature values of hydroxyl OH (6,2) suitable for determining the parameters of the seasonal variation were obtained at the Maimaga station over 16 years of measurements. The seasonal temperature variations of mesopause region were investigated in the form of annual, semiannual and a terannual component. Annual harmonic variations range from 18.2K to 64.7K, and the semiannual harmonics range from 6.8K to 26.6K. The dependence of the annual and semiannual harmonics from the solar activity was detected. Probably the dependence indicates a strengthening of the circulation of the upper atmosphere during periods of maximum solar activity.
KEYWORDS: Solar processes, Temperature metrology, Solar radiation, Spectrographs, Infrared spectroscopy, Infrared radiation, Satellites, Atmospheric sciences, Oxygen, Signal to noise ratio
On the basis of spectral observations of the mesopause emissions on Maymaga station (63°N,
129°E) during the 2000-2011 years seasonal dependence of the response received radiation
temperatures of OH (6,2) (height of the radiation 87 km) from the solar activity. Found that for the
winter and autumn seasons studied the response characteristics of the mesopause to solar activity is
positive. In winter, the greatest response observed in the intensities and temperatures.
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