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1.
A probabilistic technique is developed for assessing water level in the mouth reach of the Ural River in the course of interaction between the river runoff and irregular rises in the Caspian Sea level (positive setups) at the predicted background sea levels of –26.5 and –26.0 m abs. 相似文献
2.
In order to reconstruct the large-scale temperature and salinity fields by the method of optimal interpolation of the archival
data, we compute the correlation functions and analyze the space and time variations of the statistical structure of the fields.
On the sea surface, the thermohaline fields are spatially inhomogeneous. Thus, the correlation functions are anisotropic in
the region of the northwest shelf and close to isotropic in the inner parts of the sea. The values of correlation length vary
from season to season. In the layer of pycnocline, the temperature and salinity fields are anisotropic. In the zonal direction,
the correlation length is 2–3 times greater than in the meridional direction. The indicated anisotropy becomes stronger in
the winter season and weaker in the summer season as a consequence of the seasonal variability of large-scale circulation.
We study the dependence of the error of reconstruction of the fields by the method of optimal interpolation on the form of
approximation of the correlation functions with regard for anisotropy.
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Translated from Morskoi Gidrofizicheskii Zhurnal, No. 1, pp. 51–65, January–February, 2008. 相似文献
3.
A. B. Polonskii S. B. Krasheninnikova D. V. Basharin 《Russian Meteorology and Hydrology》2017,42(10):653-660
Average long-term and average annual values of meridional Ekman heat (mass) transport are estimated using the NCEP/NCAR (for 1948-2014) and 20CR (for 1871-2012) atmospheric reanalyses, and their interdecadal variability is analyzed. It was corroborated that the typical period of interdecadal variability of meridional Ekman transport in the North Atlantic coincides with that of the Atlantic Multidecadal Oscillation (AMO) and is about 60 years. The strengthening of northeastern trade winds and westerlies accompanied by the development of the negative phase of AMO occurred in the 1880s-1920s and in the 1960s-1990s. The opposite trend is observed for the 1930s-1950s and for the period from the 1990s till the beginning of the 21st century. 相似文献
4.
On the basis of processing of the oceanographic data accumulated for the water area of the North Atlantic in 1950–1999 (∼500,000
stations), we study seasonal and interannual variations of the principal characteristics of pycnocline within the range of
σt = 25.5–27.5 conventional density units. It is shown that the interannual oscillations of these characteristics in the entire
analyzed layer can be regarded as a superposition of fluctuations with periods from 2–3 to 10–12 yr. The typical ranges of
these fluctuations for the depths of occurrence of isopycnic surfaces and the corresponding temperature and salinity are equal
to 20–25 m, 1–1.5°C, and 0.25‰, respectively. The intensification of atmospheric circulation at middle latitudes is accompanied
by the simultaneous deepening of the pycnocline and its heating in the central part of the North Subtropical Anticyclonic
Gyre. At the same time, the process of weakening of the atmospheric circulation leads to the rise of the pycnocline and its
cooling. The complete cycle of interaction of the North-Atlantic Oscillation with the anomalies of isopycnic characteristics
(with regard for the period of their advection) is equal to ∼6–8 yr.
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Translated from Morskoi Gidrofizicheskii Zhurnal, No. 2, pp. 29–48, March–April, 2007. 相似文献
5.
North Atlantic Oscillation: Description,Mechanisms, and Influence on the Eurasian Climate 总被引：1，自引：0，他引：1
Polonskii A. B. Basharin D. V. Voskresenskaya E. N. Worley S. 《Physical Oceanography》2004,14(2):96-113
The present work is devoted to the characteristic of the North-Atlantic Oscillation and the analysis of the state-of-the-art of this problem. In the survey section of the work, we deal with the following issues: the definition of the North Atlantic and Arctic Oscillations, their interaction with oceanic processes, and their influence on the variations of climate in Eurasia. In addition, by using the COADS (Comprehensive Ocean Atmosphere Data Set) data and the data on the discharge of European and Asian rivers, we establish some new original results. It is confirmed that the anomalies of the sea-surface temperature are consequences of the integral response of the ocean to the preceding atmospheric actions and that the spectra of these anomalies are characterized by the presence of significant peaks within the band of periods of 10–20 yr. These periods correspond to inherent oceanic variability. The atmospheric response manifests itself in the form of abnormal conditions over the catchment areas of European and Asian rivers, which leads to oscillations of their discharges. As a result of the intensification of the North Atlantic Oscillation and the displacement of the centers of action of the atmosphere in the 60–90s of the previous century, the influence of this oscillation on the climatic conditions in the European-Asian region became more intense. 相似文献
6.
The linear and quadratic trends of the parameters of interaction of the atmosphere with the ocean in the North Atlantic are computed according to the archival data of the Russian Hydrometeorological Center accumulated for 1957–1990. The linear trends are regarded as probable manifestations of the anthropogenic processes. At the same time, the quadratic trends are regarded as manifestations of natural low-frequency oscillations with a characteristic period of ~65 yr. The linear trends of the sea-surface temperature (SST) and the surface air temperature (SAT) are negative at high latitudes. The thermal (SST—SAT) contrasts and the deficiency of humidity E decrease over the most part of the investigated water area, thus revealing the active influence of the North Atlantic on the trends of SAT caused by the negative feedback in the system supported by the changes in the evident and latent heat fluxes. The significant quadratic trends of various hydrometeorological parameters and total heat fluxes confirm the predominance of natural variability with a period of ~65 yr in the North Atlantic. The quadratic trend of the heat fluxes is mainly caused by the quadratic trend of E. The coincidence of the phases of long-period anomalies of the SAT and E over the major part of the North Atlantic reveals the decisive role of the variability of the ocean in supporting the interdecadal oscillations in the ocean—atmosphere system.Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 19–38, July–August, 2004. 相似文献
7.
Polonskii A. B. Voskresenskaya E. N. Basharin D. V. Mikhailova N. V. 《Physical Oceanography》2003,13(3):171-182
On the basis of reanalysis of the data of the European Center of Medium-Range Weather Forecasts for 1979–1993, we study the relationship between the interannual and intramonthly variability of the fields of surface temperature and pressure in the Atlantic-European region and the Southern Oscillation (SO). In spring, the SO is responsible for 25% of the variance of surface temperature for periods of 8–30 days in the east part of Europe and in the Mediterranean region. In this case, the zonal circulation over the North Atlantic is intensified, which manifests itself in the deepening of the Iceland Low and Azores High. For low indices of SO, 8–15-day temperature fluctuations are predominant over the Black-Sea region. At the same time, 3–4-week fluctuations are predominant over West Mediterranean. An important role in the formation of abnormal temperature conditions in the analyzed region is payed by the events of La Niño. 相似文献
8.
We describe the space-and-time structure of large-scale thermal anomalies in the upper layer in the tropical zone of the Indian
Ocean and study the mechanism of their formation. It is shown that the critical layer in which the phase velocities of propagation
of disturbances coincide with the mean velocity of the zonal current can be formed in the central part of equatorial zone
of the Indian Ocean (between 9° and 12°S). In this layer, the formation of growing disturbances is possible due to the barotropic-baroclinic
instability of the system of zonal currents. 相似文献
9.
By using the archival data of routine hydrometeorological and satellite observations, we perform the analysis of the general
regularities of manifestations of upwelling in the anomalies of the surface temperature in the northwest part of the Black
Sea at the end of the summer season. We describe the structure of coastal upwelling according to the data of a hydrological
survey carried out in the Kalamitskii Bay in September 2007 characterized by the extremely intense anomalies of sea surface
temperature. By using the data of reanalysis on the heat fluxes and the wind field, we analyze the cause-effect relations
responsible for the evolution of this upwelling. 相似文献
10.
Data of the State Observation Network on the water run-off for the whole observation period and on water levels in the delta
of the Volga River for the period of regulated run-off regime (1961–2006) are analyzed. Periods of various water content are
revealed and the current tendency of long-term run-off changes is established with the help of difference-integral curve of
recovered natural annual run-off. Periods of various degree of man’s impact on the run-off, entering the delta of the Volga
River, are marked out. The role of irretrievable anthropogenic loss and the influence of run-off regulation on its intraannual
distribution are assessed. Regularities of seasonal and long-term water level changes in the delta of the Volga River are
revealed. The run-off regulation effect on the intraannual distribution of water levels is assessed. The influence of the
water divider on the redistribution of the run-off and water levels in the delta is shown. The effect of the current increase
in the Caspian Sea level on the penetration of the backwater into the delta of the Volga River is revealed. 相似文献