Description of possible causes of the formation of anomalies of the cloud field over the Atlantic-European sector in the spring of 1996

We describe one of possible mechanisms of the formation of anomalies of the cloud field over the North Atlantic and Europe by using, as an example, the processes developed in the Atlantic-European sector during the natural synoptic season in the spring of 1996. It is shown that the anomalies of the cloud field can be classified with the use of the index of the North Atlantic oscillation and the latitude of the center of the Azorean maximum. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

On the formation of atmospheric seasonal precipitation in the Black Sea region

The climatic features of the formation of precipitation and their correlation with the baric situation in the Atlantic-European sector are studied on the basis of the data of the Sevastopol and Feodosiya coastal hydrometeorological stations. As the source data, we use the data arrays of daily precipitation at these stations in 1900–2005 and the data of reanalysis of the fields of atmospheric pressure in the Atlantic-European sector. The comparative statistical analysis of daily precipitation for the wet and dry summer and winter seasons and the estimates of extremely high levels of precipitation for the specified periods of repeatability are presented. The existence of the dependence of occurrence of wet and dry winter seasons in Sevastopol and Feodosiya on the large-scale baric fields in the Atlantic-European sector is confirmed. Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 43–51, July–August, 2008.     

Soft- and hardware for the reception and treatment of satellite and reference data and their application to monitoring hydrometeorological fields

The paper describes the functional scheme of the soft- and hardware complex designed to receive, to treat and to disseminate satellite and reference hydrometeorological data. The complex displays a high degree of integration and unification of soft- and hardware techniques and packages. The operation of the complex is studied through the monitoring of cloud fields in the Atlantic-European section of the Northern hemisphere during the winter-time synoptic season of 1995–1996. The complex is shown to be capable of identifying large-scale cloud anomalies and of estimating their coherence in the individual regions of the Atlantic-European zone. Translated by Vladimir A. Puchkin.     

Analysis of the surface circulation in the Black Sea performed by using drifting buoys with satellite communications

We present the results of drift experiments with 14LOBAN-TM buoys carried out for the first time in the Black Sea in 1987–1997. We analyze the specific features of application of buoys in summer and winter. We present the main results of investigation of the Main Black Sea Current by drift methods and joint processing of drift contact and remote infrared observations. We demonstrate the possibility of enhancement of the quality of observations due to the application of SVPB drifters of new generation equipped with underwater sails and meters of atmospheric pressure in the near-surface atmospheric layer. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Statistical Modeling of Monthly Anomalies of Atmospheric Precipitations for the Region of the Ukraine and Black Sea

The data array accumulated for the period 1946–1995 is used to select the most significant predictor of monthly anomalies of precipitation in the region of the Ukraine and Black Sea, namely, a large-scale circulation in a sector covering the North Atlantic and Europe. Three large-scale predictors (geopotential at a level of 500GPa, sea-level pressure, and the difference between the geopotentials at levels of 500 and 1000GPa) give almost identical results: their correlation with anomalies of precipitation is equal to 0.7–0.8 in winter and 0.4–0.5 in summer. The predominant mechanism of the influence of circulation on precipitations at low frequencies is the response of the trajectories of European cyclones to changes in the upper-tropospheric jet currents in the Atlantic-European sector described as the superposition of the North-Atlantic oscillation and the Eurasian mode. The decomposition of the fields of precipitations and circulation in the eigenmodes of the canonical correlation analysis opens a possibility of direct computation of the monthly average fields of precipitations for the entire territory of the Ukraine and Black Sea region according to the large-scale geopotential fields.     

Albedo of clouds and radiation conditions in the oceans

On the basis of the satellite and ship data of many-year observations, we parametrize the albedo of the ocean-atmosphere system both for the conditions of “fair weather” and for the maximum and climatic optical thicknesses of oceanic clouds. These results are used to develop a procedure of practically exact reconstruction of the monthly average fluxes of integral solar radiation and the radiation budget over the ice-free surface of the oceans according to the data of satellite measurements of albedo (Nimbus NOAA satellite, 1974–1983) for arbitrary conditions of transparency of the atmosphere and cloudiness. We determine the current and climatic monthly average values and the characteristics of interannual variability of all components of the radiation mode of the ocean-atmosphere system with a spatial resolution of 500×500 km. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Time variability of technogenic radioactivity in the Black and Mediterranean Seas

We analyse the time variability of the fields of Cs-137 concentration in the surface waters of the Black and Mediterranean Seas in 1986–1998. It is shown that more contaminated Black-Sea waters affect the levels of concentration of this radionuclide in the east part of the Mediterranean Sea. We also study the influence of atmospheric processes and water exchange through Bosporus on the radioecological situation in the east part of the Mediterranean Sea and its coastal area. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Reconstruction of the seasonal climate of the Black Sea on the basis of available hydrological data

We analyze the seasonal variability of the climatic hydrophysical fields of the Black Sea reporduced in three numerical experiments carried out according to the model of circulation. The numerical predictions are performed for a period of 12.5 yr on the basis of the hydrological data accumulated in 1983–1995. The monthly average climatic fields of the current speed are reconstructed according to the data on the climatic fields of temperature and salinity by the method of hydrodynamic adaptation (standard). It is shown that, in prognostic calculations, the seasonal variability of temperature and salinity is qualitatively close to the “standard” dependence. At the same time, the quantitative difference between the climatic behavior of the model and the standard dependence may be significant. The annual cycle of the currents is characterized by the intensification of the Main Black-Sea Current in winter. The structure of the hydrophysical fields of the sea in the model becomes much more realistic if it is based on the actual hydrological data. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

The response of cloudiness in the Atlantic-European section to the interannual variability of the North Atlantic Oscillations

The paper discusses the conditions corresponding to the largest and smallest North Atlantic Oscillations (NAOs). It is shown that in winter, when NAOs are at a minimum, the number of cyclones over the Black Sea increases. At the same time, cloudiness in the Atlantic-European section becomes heavier, compared with the largest NAO. Heavy cloudiness over the Balkan and Karpaty mountains, with NAO at a minimum, may imply the greater likelihood of Balkan cyclones’ penetration into the Black Sea region. The mechanism responsible for the generation of maximum (minimum) cloudiness in the Atlantic-European section is discussed. Translated by Vladimir A. Puchkin.     

Seasonal variations of wind and waves over Taiwan waters

We here investigate the frequency and intensity of oscillations in oceanographic data within intraseasonal time scales using spectral analysis of surface wind and wave time-series data collected at off-island weather stations or moored buoys around Taiwan. Data from marine weather stations were used to trace atmospheric conditions, while we used buoy data to examine sea states. The spectra and wavelet scalogram of the wind fields revealed oscillations with a period of around 20–33 days, and the energy density of the wind field at the off-island stations was stronger than that at the data buoy stations. However, the wavelet scalogram of the wave height measured at the buoy stations was stronger than its associated wind field. This long-period oscillation is consistent with the wavelet scalogram of the wind field calculated from the off-island weather stations. About 20–33 day oscillations exist within intraseasonal variations, which are closely linked to the atmospheric environment and to wind and ocean wave fields. Oscillations with a period of 5–10 days are a pronounced feature over northeastern Taiwan waters during the winter season and can be interpreted as the wave pattern following synoptic weather systems.     

Autumn atmospheric preconditioning for interannual variability of wintertime sea-ice in the Okhotsk Sea

Relations in year-to-year variability between wintertime Sea-Ice Concentrations (SICs) in the Okhotsk Sea and atmospheric anomalies consisting of zonal and meridional 1000-hPa wind speeds and 850-hPa air temperatures are studied using a singular value decomposition analysis. It is revealed that the late autumn (October–November) atmospheric conditions strongly influence sea-ice variability from the same season (late autumn) through late winter (February—March), in which sea-ice extent is at its maximum. The autumn atmospheric conditions for the positive sea-ice anomalies exhibit cold air temperature anomalies over the Okhotsk Sea and wind anomalies blowing into the Okhotsk Sea from Siberia. These atmospheric conditions yield anomalous ocean-to-atmosphere heat fluxes and cold sea surface temperature anomalies in the Okhotsk Sea. Hence, these results suggest that the atmospheric conditions affect the sea-ice through heat anomalies stored in sea-ice and oceanic fields. The late autumn atmosphere conditions are related to large 700-hPa geopotential height anomalies over the Bering Sea and northern Eurasia, which are related to a stationary Rossby wave propagation over the North Pacific and that from the North Atlantic to Eurasia, respectively. In addition, the late autumn atmospheric preconditioning also plays an important role in the decreasing trend in the Okhotsk sea-ice extent observed from 1980 to the mid-1990s. Based on the lagged sea-ice response to the late autumn atmosphere, a simple seasonal prediction scheme is proposed for the February–March sea-ice extent using four-month leading atmospheric conditions. This scheme explains 45% of the variance of the Okhotsk sea-ice extent.     

A model of the evolution of vertical thermohaline inhomogeneities of an oceanic thermocline taking into account the effects of double diffusion

We construct a numerical model of the evolution of the structure of an oceanic thermocline in the presence of “salt-finger” convection. The model explains the formation of a piecewise homogeneous vertical structure of the temperature and salinity fields in the ocean. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Long-term variations of the location of the upper boundary of the hydrogen-sulphide zone in the Black Sea

We analyze the dependence of climatic variations of the location of the upper boundary of the hydrogen-sulphide zone in the Black Sea on the variations of the sea level and various types of atmospheric circulation (according to A.A. Girs). It is discovered that the level of correlation between the indicated parameters is high and that the corresponding plots are in good qualitative agreement. The accumulated results enable us to make an assumption that there exists an 80–100-yr cycle of variation of all analyzed parameters and that the long-term variations of the location of the upper boundary of the hydrogen-sulphide zone can be regarded as a manifestation of global climatic variations. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Analysis of the possibilities of aGALS-3 hydrophysical towed complex

We describe the characteristics of a towed complex used for measurements in the upper layer of the ocean under the conditions of periodic deepening and lifting (scanning) of a carrier with sensors connected with the ship by a weight-carrying cable of constant lengt. For a maximum scanning range of 0–200 m and a towing speed of up to 12 knots, the measurements were performed every 1.5–2.0 km. The minimum vertical scale of recorded temperature and conductivity inhomogeneities is 0.05–0.08 m. We present the results of measurements carried out by the towed complex in a section of the frontal zone in the north-east part of the Tropical Atlantic. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Formation of the Anomalies of Hydrometeorological Fields on the South Coast of Crimea in the Years of Decreasing Solar Activity in Its 11-Year Cycles

We study the anomalies of some hydrometeorological fields in the Atlantic-European sector and on the South Coast of Crimea (SCC) in the years of decrease in solar activity in its even and odd 11-year cycles. It is shown that, in the first half of summer, the values of the sea level and surface temperature at the SCC averaged over the years of decrease of an even cycle are lower than for the same years of an odd cycle. As a result, we make a conclusion that there exists a tendency to the formation of quasi-22-year variability of some hydrometeorological characteristics near the SCC. We also discover a trend to the antiphase variability of the number of upwellings and the surface temperature at the SCC in the years of decrease in solar activity in its even and odd 11-year cycles.     

Generation of long waves in a basin of variable depth in the process of formation of a region of perturbations of atmospheric pressure

We perform the numerical analysis of the long-wave response of the free surface of a fluid in a basin of variable depth to the formation of an anomaly of the baric field for a finite period of time. In numerical experiments, we use the distribution of depths typical of the south coast of the Crimea. We also study the dependence of the dynamics of the sea level in the zone of the baric anomaly and in the shelf zone on the space and time scales of local changes in the field of atmospheric pressure in the open part of the basin. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Hydrological structure of waters of the persian gulf according to the data of observations in 1992

We describe the hydrological structure of waters of the Persian Gulf and its seasonal variability according to the data of CTD surveys carried out in February–June 1992 in the course of the cruises of the NOAA R/VMt. Mitchell aimed at the analysis of the consequences of the ecological catastrophe caused by the spread of oil spots formed as a result of war operations in the Persian Gulf in 1991. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

南半球热带外气候变量与两种ENSO的联系

This study uses the Climate Forecast System Reanalysis(CFSR) to investigate the responses of the Southern Hemisphere(SH) extratropical climate to two types of El Ni?o–Southern Oscillation(ENSO)—the eastern Pacific(EP) type and the central Pacific(CP) type in different seasons. The responses are denoted by the anomalies of climate variables associated with one-standard-deviation increase in the Ni?o3 or Ni?o4 index. The results show that in austral spring the differences in the ENSO-related anomaly(ERA) patterns of atmospheric circulation between the EP ENSO period(1979–1998) and CP ENSO period(1999–2010) are mainly associated with the change in the ENSO-PSA2 relationship. Such differences affect the ERA fields of surface air temperature and mixed layer temperature, and finally result in significant differences in sea-ice concentration anomalies in the Atlantic sector. In austral summer, significant correlation exists between the variations of SAM and both of the variations of Ni?o3 and Ni?o4 in 1979–1998, while the correlation between SAM and Ni?o4 disappears in 1999–2010. For all seasons, the strength of the climate ERAs depend on if there are close relationship between ENSO and the major climate variation modes of the SH extratropics. For the climate variables, the ERA patterns of surface air temperature are generally controlled by surface wind anomalies and mirrored by the mixed layer temperature anomalies. The mixed layer depth anomalies are primarily modulated by surface heat flux anomalies and occasionally by anomalous wind. There are strikingly strong anomalies of surface heat flux in the autumn of 1979–1998 related to the Ni?o3 variation, the period when there is only significant correlation between ENSO and PSA2. There are no evidence that the SH extratropical climate variability induced by Ni?o3 variations are stronger in the EP-ENSO period, and that variability induced by Ni?o4 variations are stronger in the CP-ENSO period.     

Spectrophotometric and iodometric methods for the detection of hydrogen sulfide in the Black Sea: Comparison of the results of analysis

We discuss the results of analysis of published data and field and laboratory investigations aimed at the solution of the problem of comparabilityof the results of detection of hydrogen sulfide in the Black Sea by spectrophotometric and iodometric methods. We show that the reproducibility of the results of spectrophotometric analysis is higher than hat of the iodometric method only in the case where the content of sulfide in a sample is less than 10–30 μMl⁻¹. When larger concentrations are involved, the traditional iodometric analysis proves to be the most precise and reliable method for the detection of hydrogen sulfide in the Black-Sea waters. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Hydrometeorological characteristics of the Black-Sea region in the years with extreme values of the Sargasso–Black-Sea index

We analyze the annual average values and the anomalies of some hydrometeorological characteristics averaged over the period since January till March near the South Coast of Crimea and in the open part of the Black Sea. It is shown that the sea-surface temperature, the surface temperature of air, and the atmospheric precipitation in the Black-Sea region are lower than the climatic mean values for the extremely high values of the index of North-Atlantic Oscillation (NAO index) (NAO ≥ 1) and the surface temperature gradient between the Sargasso and Black Seas (SBS index) (SBS ≥ 1). In the years with NAO ≤ − 1 and SBS ≤ − 1, the indicated characteristics exceed the climatic mean values. The entire process of changes in the sign of anomalies of the hydrometeorological characteristics runs with a period close to 20 yr.