The hydrology of the Southern Ocean is characterized by several oceanic fronts that together form the largest Antarctic Circumpolar Current. The methodology of synoptical monitoring of fronts is based on observations during the seasonal maritime operations for supply of Russian Antarctic stations. It happens by use of continuous registrations of variability of horizontal gradients of temperature of sea surface layer (SSLT) in situ, and horizontal gradients of surface temperature (SST) from satellite infrared (IR) data, which are taken in real-time on board of research vessel. This makes possible more detailed definition of the horizontal gradients of thermic characteristics and latitudinal location of the fronts. It can be done by means of underway data of SSLT from vessel’s automatic meteorological station, with simultaneous GPS-registration of their spatial location, on the one side; and by precise definition of geographical position of fronts zones of SST from satellite high resolution IR-images of the ocean surface, on the other side. Such data obtained during regular sub-meridional voyages of research-supply vessels between Africa and Antarctica, helps more confident than before to judge about presence/absence of trends in inter-annual changes in the latitudinal location of the main fronts in the Southern Ocean. Such a trends can be considered as an evidence of substantial change of water circulation, and as the manifestations of global warming of the sea surface layer. Within Indian sector of the Southern Ocean during 2007–2016 was registered a trend in annual shifts of seasonal positions of climatic fronts to the south.

On a basis of the analysis of archived ice charts for 1997–2017 calculations of changes in the stages of sea ice development composition in southwest part of the Kara Sea during the autumn and winter period are executed. The obtained data allowed establishing the changes in quantity (area) and corresponding thicknesses with 10 days discretization for all stages of sea ice development and the periods of their prevalence from the beginning till the end of ice formation. The essential distinctions between the stages of ice development composition for drifting and fast ice exhibiting in an earlier appearance and different relative quantity of the first year ice within the fast ice zone are revealed. Such studies were not performed earlier. Its results supplement ice conditions characteristics southwest in the part of the Kara Sea during the “warm” climatic period.

The results of a comparative analysis of the monthly mean of average, maximum and minimum values of air temperature, air humidity and wind speed calculated by daily data with one minute increment for the period from November 2006 to February 2012 during the months of operation of the meteorological station at the Novolazarevskaya airfield and directly at Novolazarevskaya station are given. The climatic parameters at two points of observation give high correlation index. The estimations of the trends in time series of climatic references at Novolazarevskaya station for the period 1961–2015 are also given.

Variability of total (Q) and absorbed (Q – R) radiation after the year 2000 at some Russian Arctic stations in comparison with the long-term variability of these characteristics since the beginning of observations and until 1992 was investigated. As estimating parameters, the normalized by multiyear averages for 1961–1990 of anomalies of annual sums of total and absorbed radiation were chosen. We have analyzed the variability of total cloudiness and integral optical thickness characterizing transparency of the atmosphere as the factors producing the largest influence on total radiation incoming to the land surface. The integral optical thickness of the atmosphere in the Arctic after 2000 was most likely determined by specifics of air pollutants coming to the Arctic atmosphere and was significantly higher in the western Arctic area, than in the eastern one. After 2000 practically at all stations considered, the income of total radiation appeared to be below the multiyear average. Significant by the absolute value, but different by the sign, changes of absorbed radiation were recorded. The long-term periods of decrease and the subsequent increase of the incoming solar radiation observed at the European stations and called as “global dimming and global brightening” were not revealed at the Russian Arctic actinometric stations.

New estimates of linear trends in the position of the level surface were obtained as a result of analysis of the data of long-term observations of sea level fluctuations at the stations of the seas of the Arctic Ocean. A rise in sea level is observed at almost all stations. In multi-year fluctuations of the level, periods characterized by different values of linear trends are identified. The reasons for the variability of local linear trends in the level of the Arctic seas from the 1950-1980 stage to the 1990-2015 period are analyzed. It is shown that the presence of local trends during the annual average levels at coast stations is a consequence of changes in climatic conditions reflected in changes in atmospheric and hydrosphere climatic indices, as well as in freshwater river runoff.

There are different points of view on the role of the atmospheric heat and moisture transport in increasing summer warming in the Arctic, which are often based on the analysis of average annual data. In this paper, the analysis of summer atmospheric transport, their influence on air temperature and water vapor content in the atmosphere, trends in multi-year transport changes are fulfilled. It is noted the important role of moisture inflows from the Arctic Ocean in the summer season and their influence on the growth of long-wave radiation and amplification of sea ice shrinking.

In this paper we present the results of studies the distinctive features of the decameter radio wave propagation based on the results of experimental measurements of radio wave propagation characteristics by the ionospheric oblique sounding (IOS) method and numerical simulation. An algorithm for numerical modeling the trajectory and energetic characteristics of the decameter radio wave propagation in the framework of geometric optics is described. The agreement between the simulated and experimental radio propagation parameters (for example, the values of the maximum observed frequencies) is demonstrated. It is proposed to use the developed diagnostic model of the HF radio channel for the purposes of forecasting in areas not provided with IOS stations.

The results of field studies of the processes of Antarctic Bottom Water formation conducted in the period from 2004 to 2016 in the Prydz Bay of the Commonwealth Sea is discussed. During this period the oceanographic observations along the 70° E section, crossing the shelf and the continental slope, were repeated nine times. In this area in the austral summer of 2004 during the AARI expedition on the r/v “Akademik Fedorov” the process of formation of bottom water has been recorded for the first time. A further study of the structure and characteristics of water masses on this section and in the adjacent area confirmed the regularity of these processes during the summer period. At the same time, a significant interannual variability of the structure, characteristics, and mechanisms of distribution of the main water masses in the section shelf, deep and bottom waters — was found. For the first time, detailed information on the bottom topography of the ocean in the vicinity of this section made it possible to show the determining role of bottom topography features in the distribution of newly formed bottom water along the continental slope. The tendency of increasing of the volume of bottom water formed in the Prydz Bay in recent years is revealed, which is associated with the intensification of the basal melting of the ice shelf leading to an increase in the volume of the formation of supercooled Shelf Water, the most important component in the formation of bottom water.

The results of hydrological and hydrochemical research of on bodies of water: ducts and lakes of the delta of the Lena River are reported here. Studies were performed during the 2015/16 summer (July-August) and winter (April) expeditionary seasons. The present work also introduces the results of field hydrochemical analyzes made immediately after sampling. The values of hydrochemical and hydrophysical indicators of ducts and lakes such as electrical conductivity, pH, permanganate oxidability, concentration of dissolved organic carbon, water color and absorption of colored organic matter were received. This obtained values supplemented significantly the available information on the delta water bodies in winter.