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High-resolution modeling is implemented to investigate an evolution of two quasi-tropical cyclones (QTC) over the Black Sea: in September of 2005 and 2018. For comparison, the quasi-tropical hurricane Zorba, that developed over the Mediterranean Sea at the end of September 2018, is considered. An assessment of factors leading to the origination and intensification of QTCs is carried out, and the predictability of the phenomenon is studied. The authors tried to reduce the analysis to the parameters obtained directly as a result of mesoscale nonhydrostatic modeling. In all the considered cases, the period of active development of cyclones was preceded by the formation of a core of warm air above the sea surface; the moisture inflow from the lateral boundaries was more important in the moisture balance. It is found that coarser spatial resolution predictions are more successful for large QTCs.

This paper focuses on the effect of sea ice melting under the effect of the mechanism of decreasing albedo of dry and wet ice and snow on the structure of atmospheric circulation. In particular, the Impact on storm tracks in the Pacific and Atlantic Oceans is analyzed. Extreme weather events are usually associated with atmospheric blocking conditions. Blocking is such meteorological conditions in which a large anticyclonic atmospheric vortex is observed over an area for several days. The Molteni-Tibaldi blocking criterion and the magnitude of the local anticyclonic wave activity (LAWA) are used to estimate the number of blockings. Extreme values of LAWA may indicate the presence of atmospheric blockings. As a result, there is a weakening and eastward shift of Atlantic storm trajectories. There is almost no influence on the Pacific storm tracks.

Many large-scale dynamic phenomena in the Earth’s atmosphere are associated with the processes of propagation and breaking of Rossby waves. A new method for identifying the Rossby wave breaking (RWB) is proposed. It is based on the detection of breakings centers by analyzing the shape of the contours of potential vorticity or temperature on quasimaterial surfaces: isentropic and iserthelic (surfaces of constant Ertel potential vorticity (PV)), with further RWB center clustering to larger regions. The method is applied to the set of constant PV levels (0.3 to 9.8 PVU with a step of 0.5 PVU) at the level of potential temperature of 350 K for 12:00 UTC. The ERA-Interim reanalysis data from 1979 to 2019 are used for the method development. The type of RWB (cyclonic/anticyclonic), its area and center are determined by analyzing the vortex geometry at each PV level for every day. The RWBs obtained at this stage are designated as elementary breakings. Density-Based Spatial Clustering of Applications with Noise algorithm (DBSCAN) was applied to all elementary breakings for each month. As a result, a graphic dataset describing locations and dynamics of RWBs for every month from 1979 to 2019 is formed. The RWB frequency is also evaluated for each longitude, taking into account the duration of each RWB and the number of levels involved, as well as the anomalies of these parameters.

Stability of the stratospheric polar vortex in the winter–spring period is one of key factors of the duration and scales of stratospheric ozone depletion in a polar region. The Arctic polar vortex attains its peak intensity in winter, whereas the Antarctic vortex usually strengthens in early spring. As a result, large-scale ozone depletion occurs every year from August to November over the Antarctic, and short-term ozone loss occasionally occurs from January to March over the Arctic. In this work, we analyze the reason for the high strength and stability of the Antarctic polar vortex in the winter–spring period. A good agreement between the seasonal variations in the temperature of the subtropical lower stratosphere and in the zonal wind in the lower subpolar and polar stratosphere in the Southern Hemisphere is shown on the basis of ERA-Interim reanalysis data. The results of numerical simulations with the PlaSim-ICMMG-1.0 model show acceleration of zonal wind in the subpolar region with an increase in the temperature of the subtropical stratosphere. Thus, the winter–spring strengthening of the Antarctic polar vortex occurs due to an increase in the stratospheric equator-to-pole temperature gradient caused by the seasonal increase in the temperature of the lower subtropical stratosphere in this period.

The amplified warming of the Arctic is one of several factors influencing atmospheric dynamics. In this work, we consider a series of numerical experiments to identify the role of Arctic sea ice reduction in affecting climate trends in the Northern Hemisphere. With this aim in mind, we use two independent mechanisms of ice reduction. The first is traditionally associated with increasing the concentration of carbon dioxide in the atmosphere from the historic level of 360 ppm to 450 ppm and 600 ppm. This growth increases air temperature and decreases the ice volume. The second mechanism is associated with a reduction in the reflectivity of ice and snow. We assume that comparing the results of these two experiments allows us to judge the direct role of ice reduction. The most prominent consequences of ice reduction, as a result, are the weakening of temperature gradient at the tropopause level in mid-latitudes, the slower zonal wind at 50–60∘ N, intensification of wave activity in Europe, Western America, and Chukotka, and its weakening in the south of Siberia and Kazakhstan. We also consider how climate change may alter regimes such as blocking and stationary Rossby waves. The study used the INM-CM48 climate system model.

This review outlines the most significant results of research in dynamic meteorology performed by Russian scientists in 20152018. It is part of the Russian National Report on Meteorology and Atmospheric Sciences submitted to the International Association of Meteorology and Atmospheric Sciences (IAMAS). The review is supplemented by a list of main publications of Russian scientists on dynamic meteorology in 20152018.

This review outlines the most important results of research in dynamic meteorology performed by Russian scientists in 2015–2018. It is part of the Russian National Report on Meteorology and Atmospheric Sciences submitted to the International Associations of Meteorology and Atmospheric Sciences (IAMAS). A list of major published papers on dynamic meteorology over 2015–2018 is attached.

The stratospheric polar vortex strength in spring determines to a great extent the duration and intensity of ozone depletion in the polar regions. The size of the Antarctic ozone hole usually reaches its maximum in September and then drops off during October and November. However, in 2015, a significant increase in the ozone hole area relative to climatological mean values was observed in October under the strong polar vortex conditions, and in 2002 its abnormal decrease was recorded as a result of the splitting of the polar vortex in September. A significant increase and decrease in temperature of the lower subtropical stratosphere in the spring of 2015 and 2002, which contributed to a corresponding increase and decrease in the stratospheric meridional temperature gradient during these years, was considered as a possible cause for the polar vortex strengthening in 2015 and its weakening in 2002.

In a number of works, it is shown that the reaction of extratropical circulation to strong eruptions of tropical volcanoes is the strengthening of the Northern polar vortex. The observations show that at the winter following after the autumn eruptions of volcanoes in the tropical belt there is a positive anomaly in the intensity of the polar vortex. In this paper, the reaction of the Northern polar vortex to tropical volcanic eruptions is numerically investigated. The possible mechanism of vortex amplification is shown.

The system of the cyclic assimilation of data on atmospheric conditions used in the West Siberian Administration for Hydrometeorology and Environmental Monitoring is described. It is based on the WRF-ARW mesoscale atmospheric model and on the WRF 3D-Var system of the three-dimensional variational analysis of data. The system is verified when the first approximation data (6-hour forecast) and WRF-ARW forecasts with the lead time up to 24 hours are compared with the observational data. The problems of assimilation of observations from the AMSU-A and AIRS satellite instruments are considered. The effect of using AMSU-A and AIRS for the analysis in the Novosibirsk region is estimated. The experiments demonstrated that the cyclic data assimilation system operates successfully. The AMSU-A observations improve the quality of analyses and forecasts in winter. In summer the impact of satellite observations on the forecast skill scores is ambiguous. Good short-term forecasts are provided by the initial conditions obtained using the system of detailing of the NCEP large-scale analysis.

Potential vorticity (PV) streamers and cutoffs are indicators of Rossby wave breaking (RWB) near the extratropical tropopause. The Rossby wave breaking forms an elongated high-PV stratospheric air tongue that extends to the equator and a tropospheric low PV air tongue that extends to the pole. There are two types of RWB: equatorward and poleward ones. Frequently, PV tongues stretch into narrow filaments, so-called PV streamers that split into PV cutoff vortices. Here the terms stratospheric PV streamer and cutoff refer to stratospheric features of isentropic surfaces (PV > 2 PVU; where 1 PVU = 10−6 K_kg−1 m2_s−1). In this paper, we study a configuration of the potential vortex field using model data. The main areas of RWB in winter and summer are shown. Atmospheric blocking events represent some of the most high-impact weather patterns in the mid-latitudes, but they have often been the cause of unsuccessful future climate projections. In this paper, we have examined the seasonal frequency of global blocking events in relation to a change in the mean EOF index based on some modeling results obtained by using a climate system model, PlaSim-ICMMG-1.0.

In the last decades, poleward displacements of elements of the general atmospheric circulation such as the Hadley Cell and storm tracks have been observed. On the basis of results of the numerical modeling of climate dynamics using an idealized model of the climatic system, we showed that the tendency to the displacement of storm tracks to the poles in the Northern Hemisphere would continue under the conditions of climate warming (according to the RCP 8.5 scenario). We also discuss the other peculiarities of the dynamics of the general circulation under the conditions of variable climate, which were revealed in the numerical experiment.

In this paper, responses of the general circulation of the atmosphere to climate changes are simulated with a spectral model. It is shown that as the meridional temperature gradient decreases the Hadley circulation weakens and its boundaries move to the poles. The troposphere height dynamics versus the equilibrium temperature of atmospheric radiation is investigated. A relation between the characteristics determining the baroclinic instability in the atmosphere is obtained.

Considered is the application of the WRF-ARW atmospheric model to computing weather forecasts for the Siberian region. Provided are some verification scores of the WRF-ARW as compared with those of the NCEP global weather model (USA). The WRF-ARW forecasts for the European part of Russia are briefly considered. The verification scores demonstrate that WRF forecasts are useful during the warm season whereas freely distributed NCEP forecasts have some advantages during the cold season. Described is the software complex used in the West Siberian Territorial Administration for Hydrometeorology and Environmental Monitoring and intended for modeling the atmospheric dynamics over the Siberian region which is based on WRF-ARW. Given is a description of the methodology and specific features of the program realization of the complex.

The role of the ocean in the response of the climate system to an increase in the atmospheric CO2 concentration is investigated by using a system of numerical models, ICMMG-PlaSim. The results of this study are summarized as follows: a) the ocean, to some extent (up to 20%), contributes to the increase in the annual mean state and to the decrease in the amplitude of seasonal oscillations (by 2-3%), which ultimately leads to insignificant changes in the summer period and to a significant mitigation of winter, b) the ocean stabilizes the annual mean state of the Arctic oscillation, making it practically unchanged with increasing CO2 concentration but, at the same time, contributes to the significant increase in the amplitude of the seasonal cycle of this oscillation, c) the ocean enhances the temperature (or thermal) component of the seasonal variation associated with the appearance of additional areas freed from ice cover, with an additional average increase in the temperature of the atmosphere at the ice edge. Besides, the ocean enhances the seasonal oscillations of this component, so that the summer manifestations become much stronger, d) our tests have revealed that the role of the Arctic dipole under global warming is insignificant. These conclusions, though, may undergo significant changes under a more detailed consideration of carbon cycles in the atmosphere, ocean, and land.

The response of extra-tropical evergreen and deciduous Russian forest ecosystems to a wide range of atmospheric background conditions is considered. This study is performed by using a land-surface model, JSBACH. Two numerical experiments are carried out: with hotter and more humid (model PLASIM) and more moderate (model INMCM4) atmospheric background conditions. A perturbation in the climate system is set by using the RCP 8.5 climate scenario. The study has shown a geographical redistribution of the extra-tropical evergreen and deciduous forests across Russia as well as an increase in their fractions in some already forested regions. An increase in the gross and net CO2 assimilation and respiration of these types of forest vegetation, as their response to the climatic disturbances, is obtained. However, even under the conditions of extremely intense climatic disturbances the Russian forest ecosystems will continue to act as CO2 sinks.

Presented is a recently started Russian Science Foundation project “Virtual computational information environment for analysis, evaluation and prediction of the impacts of global climate change on the environment and climate of a selected region” aimed at development of accessible in Internet a computation and information environment providing unskilled in numerical modeling and software design specialists, decision-makers and stakeholders with reliable and easily used tools for in-depth statistical analysis of climatic characteristics, and instruments for detailed analysis, assessment and prediction of impacts of global climate change on the environment and climate of the targeted region. Two actively discussed nowadays problems are addressed by the project. The first one is a development of an environment in which scientists from different disciplines, stakeholders and decision makers, regardless of their geographical position, can freely access various data resources and processing services through a Web browser. Since progress in development of so called virtual research environment is based on information-computational technologies it will be discussed in this paper in more details. The second problem belongs to basic and applied climatology and will be discussed here rather briefly. It is a provision of interested parties with detailed climatic and ecological characteristics of targeted region and tools allowing get scientifically solid data necessary for the study of regional economic, political and social consequences of global climate change.

A brief review of the results of investigations carried out by Russian scientists in the field of dynamic meteorology in 2007-2010 is presented. This review is based on the information prepared by the Commission on the Dynamic Meteorology of the National Geophysical Committee, Russian Academy of Sciences, and included in the general information report of the Section of Meteorology and Atmospheric Sciences at the XXV General Assembly of the International Union of Geodesy and Geophysics.

Vegetation plays a key role in the global climate system via modification of the water and energy balance. Response of different vegetation types to present and projected climatic conditions was assessed for Siberia. The study was performed using JSBACH land surface model with atmospheric conditions obtained from INMCM4 modelling results. A climate change was determined according to the RCP 8.5 scenario. A geographical redistribution of extratropical forest and grass vegetation and weakening of a canopy ability to absorb carbon dioxide from the atmosphere were obtained for climate warming conditions for Siberia. It was established that Eastern Siberia is more sensitive to climate forcing than Western Siberia.

This study is devoted to the influence that anomalous snow cover in the Siberian autumn has on the surface temperature in the winter months using the intermediate complexity model of a climate system. The possible mechanisms of the effect that a thermal forcing anomaly on surfaces attributed to the troposphere-stratosphere interaction has on the temperature regime in winter are considered.

The climate dynamics in Northern Eurasia under the conditions of global climate change is studied based on atmosphere-ocean coupled general circulation models. Feedbacks for some parameters of the atmosphere are assessed and analyzed. The role of the biosphere in the climate dynamics of the 21st century is investigated with allowance for the structure of the surface layer, vegetation layer, soil, and hydrology dynamics. Peculiarities of the dynamics of the North Atlantic and the Arctic Ocean are explored over periods pertaining to various phases of the North Atlantic Oscillation (NAO) index.

A brief review of the studies performed by Russian scientists in dynamic meteorology in 2003–2006 is presented. This review is based on the material prepared by the Commission on Dynamic Meteorology of the National Geophysical Committee of the Russian Academy of Sciences and included in the general information report of the Section of Meteorology and Atmospheric Sciences at the 24th General Assembly of the International Union of Geodesy and Geophysics.

In this paper, we explore how the extratropical troposphere responds to a polar stratospheric temperature decrease, accompanied by strengthening polar vortex. For this purpose, use is made of a spectral general circulation model with zonally symmetric boundary conditions on surface and a heat source given analytically.

The dynamics of the climate and surface hydrology of northern Eurasia under the conditions of global climate changes is studied using coupled models of the atmospheric and oceanic general circulation. Feedbacks are assessed and analyzed for some parameters of the atmosphere and surface hydrology. The role of the biosphere (including the surface air layer, the vegetation layer, soil, and the hydrosphere) in the dynamics of the climate of the 21st century is studied. The features of the dynamics of the northern Atlantic seas during the periods corresponding to different phases of the North Atlantic Oscillation index are studied.