A comprehensive climatic analysis has been carried out in the Mondy high-altitude station in the Eastern Sayan Mountains based on long-term data for the period 1948-2020. The anomalies of the average values of air temperature, atmospheric pressure, the amount of precipitation and the values of the fluxes of reflected radiation from the upper boundary of the clouds were calculated. The seasonal features of climate changes at different heights of the troposphere are revealed, the frequency of large anomalies of meteorological values is calculated. The periods of the year are highlighted, which significantly complicate astronomical observations over the high-mountainous regions of the Eastern Sayan Mountains in the modern period.
The tropopause is an important object of the circulation regime of the upper atmosphere, the temperature and wind characteristics of which can affect the processes in the middle and lower troposphere. Jet streams often pass near the tropopause level, which affect the transport and propagation of atmospheric pollutants. The paper analyzes the seasonal features of the wind regime at the tropopause level in the southern regions of Irkutsk region. It was revealed that the observed climate changes in Irkutsk region are closely consistent with changes in the meridionality of flows and wind speed at altitudes. The increase in the contribution of the southern winds during the warm season should be considered when assessing the ecological state of the region, especially during periods of dust storms in Mongolia and China.
The paper presents the results of 2D numerical simulations with a magnetohydrodynamic model "shallow water" which was used to estimate the influence of magnetic field on increments of instabilities in the tachocline caused by anomalies of the mean flow. Calculations confirmed the previously obtained result about the strong influence of anomalies of the mean flow on the instabilities of the differential rotation. Average magnetic field of relatively small magnitude stabilized development instabilities, but when it reaches a critical value, stabilization stopped and typical time of instabilities development sharply decreased. Also instabilities significantly well depended on amplitudes of initial perturbation velocity field and the magnetic field.
The calculations of the anomaly criteria for average annual values of air temperature at the Earth's surface in the European, Siberian and Far Eastern sectors for the period 1948-2018 have been performed according to NCEP / NCAR Reanalysis. Changes in the criteria for temperature anomalies near the Earth's surface and at altitudes of isobaric surfaces of 850 hPa (lower troposphere), 500 hPa (middle troposphere) and 300 hPa (upper troposphere) are analyzed. The results indicate an increase in the degree of temperature variability in the period 2007-2018 and increasing the area of the territory with an anomalous distribution of average temperatures. Also, good agreement was found on changes in temperature anomalies in the regions.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.