Variability of atmospheric circulation under the climate change in West Siberia in the late 20th–early 21st centuries

The estimates of spatiotemporal variability of climatic parameters in West Siberia are obtained over the period of 1976-2014. It is revealed that this variability is affected by the parameters of atmospheric circulation such as wind speed components, relative vorticity, and large-scale circulation indices. It is found that in winter the warming changed into the cooling that is particularly associated with the change in atmospheric circulation patterns described by the SCAND index.     

Extreme wind speeds in the European sector of the Arctic

Variations in extreme wind speed over the European part of the Arctic are studied from the data of meteorological observations, reanalysis, and modeling based on the INM CM4 climate model. It is demonstrated that the extremes determined from the observational data are a mixture of two datasets well simulated by the Weibull distribution. According to the special metaphoric terminology, they are called “black swans” and “dragons.” The analysis of extreme wind speeds based on the reanalysis and INM CM4 data demonstrated that they consist of “black swans” only. This important fact indicates that the models (at least those with medium horizontal resolution) are not able to simulate some essential circulation mechanisms causing the formation of significant anomalies of wind speed. Hence, the problem of direct identification of wind speed extremes based on the atmospheric modeling remains open.     

Ozone content over the Russian Federation in the second quarter of 2016

The review is compiled on the basis of the operation of the total ozone (TO) monitoring system in the CIS and Baltic countries that functions in the operational regime at the Central Aerological Observatory. The monitoring system uses the data from the national network equipped with M-124 filter ozonometers under methodological supervision of the Main Geophysical Observatory. The quality of the functioning of the entire system is under the operational control based on the observations obtained from the OMI satellite equipment (NASA, the United States). The basic TO observation data are generalized for each month of the second quarter of 2016 and for the quarter as a whole. The data of routine observations of surface ozone content carried out in the Moscow region and Crimea are also presented.     

Studying the effects of vortices flowing around seamounts on ice properties from satellite microwave data

The changes are considered in the computation and map representation of the scattering index (SI) of thick first-year ice identified from the MTVZA-GYa radiometer data. For the first time improved ice SI maps enabled detecting the zones of the low values of sea ice SI which were steadily formed in the same areas over the Lomonosov and Gakkel ridges. It is demonstrated that the intense local ice drift formed under the influence of the vortices flowing around seamounts, may be a reason for the formation of such zones. The cases are considered when the zones of the low values of ice SI were of synoptic scale (up to 1200 km) and could have been the result of the independent influence of the vortices flowing around seamounts and strong surface wind. The utility of new SI maps is noted for monitoring the areas where the vortices flowing around seamounts may considerably modify propeties of the sea ice cover.     

Circulation anomalies in the atmospheric centers of action during the Eastern Pacific and Central Pacific El Niño

Based on the statistical analysis the teleconnections between circulation anomalies in the atmospheric centers of action and sea surface temperature anomalies are revealed for two types of El Niño. It is demonstrated that for the Eastern Pacific El Niño stronger teleconnections are registered in the Northern Hemisphere whereas the response to the Central Pacific El Niño is much stronger in the Southern Hemisphere. The Central Pacific El Niño is characterized by the more rapid signal propagation from the tropical zone to distant regions. In some cases the pattern of interaction with the atmospheric circulation considerably differs for two types of El Niño that defines differences in the fields of weather anomalies.     

Climate changes in atmospheric radiation parameters from the MSU meteorological observatory data

Variations in radiation fluxes and the factors that define them and their redistribution in the atmosphere are analyzed using the data of long-term ground-based measurements at the Meteorological Observatory of Lomonosov Moscow State University. It is demonstrated that since the middle of the 1990s trends in many atmospheric radiation parameters have changed as compared to the trends observed in the previous years. For some parameters the trends are significant, are kept for a long period of time, and. hence, can be considered as climate changes. The potential effects of these changes on the regional warming are assessed.     

Intense mesocyclones in the Black Sea region

The statistical study of intense mesoscale cyclones formed in the Black Sea region in 1979-2013 is carried out using the surface wind data of the RegCM climate model. Such cyclone parameters as intensity, lifetime, area, height, and trajectories over the sea as well as the place and time of origin are considered. The distribution of mesocyclones by months and times of day is considered. The obtained results are compared with the results of a statistical study on the Black Sea mesocyclones based on the PRECIS climate model. Possible causes for differences in data on the intensity and number of mesocyclones simulated by RegCM and PRECIS models are considered.     

Eddies in the ocean and atmosphere: Identification by satellite imagery

The results are presented of using a new approach that helps to detect and compute the parameters of eddies in the ocean and tropical cyclones in the atmosphere based on satellite imagery. The approach is based on the concept of dominant orientation of thermal contrasts (DOTC). DOTC is an angle of the statistically significant orientation of brightness contrast in the specified vicinity of the image. DOTC highly correlates with the directions of flows; it is a base for construction of models for identification of eddy motions, namely, synoptic eddies in the oceans and tropical cyclones in the atmosphere. The model-based identification of one or another eddy allows estimating such parameters as the center position, shape, size, and sign (cyclone or anticyclone) of the eddy, and the size of the tropical cyclone eye. Based on the proposed approach, technologies of automatic identification and monitoring of oceanic eddies and tropical cyclones are developed. The results of the practical use of these technologies are presented for the recent years.     

Regional climate changes and river runoff in Azerbaijan

Urgent current problems, namely, the climate change and its effects on river runoffare considered. The regional climate change at different altitudes and in separate regions of Azerbaijan is studied using long-term data of hydrometeorological observations. The trend towards the decrease in annual river runoff and peak flood discharge as well as towards the increase in winter (low-water) runoff is observed due to the influence of regional climate change.