G.V. Surkova

The COSMO-Ru system of nonhydrostatic mesoscale short-range weather forecasting of the Hydrometcenter of Russia: The second stage of implementation and development

Described is the second stage of the work (2011-2014) on the implementation and development of the COSMO-Ru system of nonhydrostatic short-range weather forecasting (the first stage of the implementation and development of the COSMO-Ru system is described in [7, 8]). Demonstrated is how the research activities and ideas of G.I. Marchuk influenced modern methods for solving the systems of differential equations that describe atmospheric processes (in particular, the version of the Marchuk’s splitting method is used to find the solution of the finite-difference analog of the system of differential equations in the COSMO-Ru model); it is shown how he contributed to the development of the methods of assimilation of meteorological information associated with the use of adjoint equations. Given is a brief description of the COSMO model of the atmosphere and soil active layer, the COSMO-Ru system, and research activities on this system development.

Atmospheric circulation and storm events in the Black Sea and Caspian Sea

Extreme sea storms are dangerous and a potential source of damage. In this study, we examine storm events in the Black Sea and Caspian Sea, the atmosphere circulation patterns associated with the sea storm events, and their changes in the present (1961–2000) and future (2046–2065) climates. A calendar of storms for the present climate is derived from results of wave model SWAN (Simulating WAves Nearshore) experiments. On the basis of this calendar, a catalog of atmospheric sea level pressure (SLP) fields was prepared from the NCEP/NCAR reanalysis dataset for 1961–2000. The SLP fields were subjected to a pattern recognition algorithm which employed empirical orthogonal decomposition followed by cluster analysis. The NCEP/NCAR reanalysis data is used to evaluate the occurring circulation types (CTs) within the ECHAM5-MPI/OM Atmosphere and Ocean Global Circulation Model (AOGCM) for the period 1961–2000. Our analysis shows that the ECHAM5-MPI/OM model is capable of reproducing circulation patterns for the storm events. The occurrence of present and future ECHAM5-MPI/OM CTs is investigated. It is shown that storm CTs are expected to occur noticeably less frequently in the middle of the 21st century.

Regional Climate Variability

Climate variations have been registered in the Aral Sea area time and again. In recent decades the anthropogenic effect has become a significant contributing factor. It became prominent, firstly, due to global changes caused, in particular, by the growing level of greenhouse gases in the atmosphere, and, secondly, due to regional variations – shrinking of the Aral Sea area. The latter fact leads to growing continentality of the local climate. During the last century the mean annual air temperature in the Aral region has risen by more than 1°C. The most perceptible warming is recorded in the transitional seasons. Long-term data on precipitation have revealed their great year-to-year variability and some increase of the annual precipitation due to the growing precipitation in the cold season.

Occurence Frequency of Storm Wind Waves in the Baltic, Black, and Caspian Seas under Changing Climate Conditions

The article proposes the method of climatic forecast of the occurrence frequency of synoptic conditions causing severe hydrometeorological events as well as severe events that are genetically related to them, in particular, storm wind waves. The choice of sea level pressure field as an indicator of atmospheric conditions of storm waves is substantiated. The algorithm for the method implementation is developed. It includes the processing of observational/reanalysis data; wind wave simulation; the systematization of synoptic conditions that accompany storm waves under the modern climate; the assessment of the ability of climate models of atmospheric and oceanic general circulation to simulate correctly the frequency of the revealed types of synoptic conditions for the modern climate; and the forecast of the frequency of these types for the possible scenarios of the future climate.

Forecasting the transport and transformation of atmospheric pollutants with the COSMO-ART model

The COSMO-ART model is used at the Hydrometcenter of Russia for the routine forecast of air pollutant concentrations. The COSMO-Ru7-ART system is able to simulate adequately the values of concentration of impurities in the atmosphere. The system includes the module for estimating the emission of pollutants to the atmosphere from forest fires that was successfully tested on the case of forest fires occurred in the summer of 2010 for the European part of Russia. The accurate forecast of pollutant concentration has also a positive effect on the air temperature forecast due to taking into account the aerosol feedback on radiation.

Air recirculation and ventilation in the coastal regions of the Black Sea

An initial investigation of recirculation is carried out for the coast of the Black Sea. The local mesoscale circulations (land-sea breezes, mountain and valley winds) in coastal areas are shown to be an additional risk factor in creating favorable conditions for air stagnation and accumulation of air pollutants in the surface atmosphere layer. Two types of annual recirculation patterns are revealed for northern and north-eastern coast of the Black Sea. Long-term changes in recirculation are investigated. It is shown that the recirculation parameter values remained quasistable until the mid-1970s. Since 1976–1977, steady intensification of recirculation in both winter and summer is identified.

On the effect of large-scale atmospheric transport on chemistry and amount of atmospheric precipitation in the center of European Russia

The dependence of precipitation amount, acidity, and ionic composition on the atmospheric circulation is studied based on the computation of the back trajectories over the period of 1982–1993. Quantitative estimates of basic parameters of trajectories are derived, and their significant difference in the summer and wintertime is considered. The trajectory frequency for the cases with precipitation in the center of European Russia is computed at the regular grid points depending on the diurnal precipitation amount, acidity, and sulfate/chloride ratio. It is shown that in case of abundant precipitation both in summer and winter the highest frequency of trajectories is observed in the same regions. In the case of low precipitation, seasonal differences are observed. It is revealed that precipitation with pH > 5 is mostly connected with the air inflow from Scandinavia and the north of European Russia, while during the trajectory passage over Central and Southern Europe pH < 5 prevails in precipitation. The chlorine ions prevail most often when trajectories pass over central regions of the Mediterranean and of Middle Asia and (although somewhat less) over Scandinavia and northern Russian seas.

Atmospheric circulation and storm events in the Baltic Sea

Abstract The storm events in the Baltic Sea are examined in connection with the main weather patterns grouped into the circulation types (CTs), and their changes in present climate. A calendar of storms was derived from results of wave model SWAN (Simulating WAves Nearshore) experiments for 1948-2011. Based on this calendar, a catalogue of atmospheric sea level pressure (SLP) fields was prepared for CTs from the NCEP/NCAR dataset. SLP fields were then analyzed using a pattern recognition algorithm which employed empirical orthogonal decomposition and cluster analysis. For every CT we conducted an analysis of their seasonal and interannual changes, along with their role in storm event formation. An increase of the storm CTs’ frequency in the second part of the 20th century was shown to be in a close agreement with teleconnection circulation patterns such as the Arctic Oscillation, North Atlantic Oscillation and the Scandinavian blocking.

Simulation of spread of air pollution plumes from forest fires with the use of COSMO-Ru7-ART chemical-transport model

A method for calculating the emission of pollutants from forest fires to the atmosphere is incorporated in COSMO-Ru7-ART calculation complex and makes it possible to correct the input data in the simulation of the spread of the pollution plume from fire. The emission factor is estimated according to the type of vegetation and its mean biomass for known (or assumed) fire area and duration. The pollution spread is forecast taking into account the chemical and physical transformation of pollutants. The method is tested for the cases of severe fires at the center of European Russia in August, 2010, with the use of the COSMO-Ru7-ART chemical-transport model. The simulations and observations are compared for the territory of the Meteorological Observatory of Moscow State University.

Space-detailed climatic forecasting of air temperature and precipitation in Eastern Siberia on the basis of accounting for local features of the underlying surface

A physical-statistical approach is used for space specification of forecasting fields of air temperature and precipitation in the mid-21st century in Eastern Siberia. The initial data on the monthly mean values representing ensemble-averaged results of 12 general circulation models of the atmosphere and the ocean, with a 2° × 2° latitude-longitude grid are specified on a 12.5 × 12.5 km grid accounting for local features of surface topography and reflectivity. The most pronounced effect of increasing space resolution is found in the areas with complicated relief, especially in summer. This corresponds to physical properties of the processes affecting local features of precipitation and air temperature fields and demonstrates efficiency of the approach under use.