Registration Number
0213U004723,
0113U005901
, R & D reports
Title
Variability of parameters of ocean and atmosphere interaction and oceanographic characteristics in the Southern ocean and Antarctic adjacent areas in connection with global climatic processes.
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Head
Polonsky Alexander Borisovich,
Registration Date
25-12-2013
Organization
Marine Hydrophysical Institute NAS of Ukraine
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During performance of works the arrays of monthly average values of air temperature and spreading surface, atmospheric pressure, wind speed, balance of short-wave and long-wave solar radiation on Earth surfaces, sensible and latent heat flux from NCEP/NCAR reanalysis during 1948-2012; monthly average values of radiation balance and full thermal balance of the Earth surface; the anomalies of aforementioned meteoelements; values of these parameters, averaged for warm (November-April) and cold (May-October) of half-year of Southern hemisphere; the array of statistical characteristics of temperature and salinity spatial-temporal variability (climatic average values, root-mean-square deviations (RMS), RMS of data rows in which oscillation with the seasons less than 5 and less 10 years are depressed, linear trends and their statistic significant) in the South Atlantic; data set of vorticity of tangential stress of wind friction and current speed in the Atlantic sector of Southern ocean have been obtained. Used this data, the variability of air temperatures, atmospheric pressure, wind speed, full thermal balance components are investigated in Southern hemisphere in warm and cold half-year. The spatial-temporal variability of temperature and salinity and decadal variability of ocean-atmosphere system characteristics in the Atlantic sector of Southern ocean is investigated. Seasonal and interannual variability of geostrophic transport in Antarctic circumpolar current (ACC) zone is investigated. According to passing measurements of sea surface temperature (SST), obtained on R/V "Academic Fedorov" in December, 2011 and January-February, 2012, the data of hydrological sounding of the upper 200-meter ocean layer the thermohaline water structure in coastal areas of Indian sector of Antarctica is investigated. Distribution of radiation balance has shown that, both in warm, and in cold the seasons the ocean heats up, and negative values of radiation balance are observed only in Antarctica in connection with high ice albedo. Trends of radiation balance for the specified season are not significant. The total turbulent heat flux is directed from ocean to atmosphere in both considered the season. Only in Antarctica and adjacent water area the values of turbulent heat flux is negative. Variability of this characteristic over continents 10 times less, than over oceans. Significant trends are observed only on ice boundary. The thermal balance values on the ocean surface have an inverse sign in warm and cold half-year, except for Antarctica, where a surface heat balance always the negative. Over continents the thermal balance variability 10 times less, than over oceans. It is revealed that 95% significant level positive temperature trends are observed in areas of the Southern branch Antarctic Circumpolar current and the moderate and subantarctic latitudes between 40 and 60W. Negative trends are observed in the region of Central branch ACC. Significant on 95% level negative trends of salinity are observed in region АCC, positive trends - in southern part of the Subtropical region. The greatest RMS temperature rows in which the linear trend is cleaned, and RMS temperature rows in which oscillations with the seasons are depressed less than 5 and less 10 years, are observed in areas of the Subantarctic region and Front of Southern branch АCC, however the greatest variation coefficient of these rows are marked in the sea drifting ices field. The greatest RMS and variation coefficient of salinity rows in which the linear trend is cleaned, and RMS and variation coefficient of salinity rows in which oscillations with the seasons are depressed less than 5 and less 10 years, are observed in the Antarctic region in the area of the Central branch АCC, and also in the Subantarctic region of the Atlantic sector of Southern ocean. The minimum variability of temperature and salinity is marked in Weddell Sea and on the Antarctica shelf (in the Antarctic coastal region). The greatest variability of a zero-line position of vorticity of tangential stress of wind friction is marked in the area located between Greenwich meridian and 40W. Here it is displaced to the south, thus the displacement value can reach 3-5 latitude degrees. The least variability is marked in the western part of the Atlantic sector of Southern ocean (to the West from 54W), and the displacement value does not exceed 1 degree of latitude. It is shown that intensifying of ACC transport on seasonal and interannual scales are observed in the end of summer and in early autumn of Southern hemisphere. The maximum seasonal variability of transports is observed in the areas of weakening of annual-average geostrophic speed of ACC. Seasonal variations of ACC transports weaken in east direction. Reaction of geostrophic transport's variations to SOI index changes is most expressed in areas with the raised values of annual-average speeds of ACC. To the West and the East from Antarctic Peninsula the correlation of interannual transport's anomalies with SOI and AAO indexes have an inverse sign which can be a consequence of influence of the Antarctic Dipole mode. The correlations connection of transport's anomalies with AAO index as a whole more low, than with SOI index. According to passing measurements of sea surface temperature, obtained on R/V "Academic Fedorov" in December, 2011 and January-February, 2012, the data of hydrological sounding of the upper 200-meter ocean layer the thermohaline water structure in coastal areas of Indian sector of Antarctica is investigated. Shown that along coast of Antarctica water temperature basically was above air temperature that is caused by delay of ocean reaction on the synoptic processes in atmosphere in work period - the cold air masses transport from the Antarctic continent in the open ocean. It is shown that in the Antarctic stations areas two basic types of waters structure were observed. It is coastal waters type with quasi-monotonous depressing of temperature in the upper 150-meter layer and oceanic type with well-marked subsurface temperature minimum, characteristic for the transformed Antarctic Winter water mass. Measurements at the many-daily station in Sanne fjord have shown that in second half of season of measurements within layer from 35 to 50 m there is a layer anomalously warm waters below which the layer of increased salinity waters. Advection of warm waters from adjacent or more remote ocean areas can be the possible mechanism of formation of this warm layer, the variant of strongly transformed Upper Circumpolar Deep water mass transport in area of researches thus is not excluded. New knowledge about the climate changes mechanisms on regional and global scales, obtained in result of the conducted researches in South Ocean, can find further application for the decision of ecological problems, estimation of quality of the coastal ecosystems state and rational development of coastal resources of the Antarctic region.
Product Description
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Є.А. Базюра
О.В. Федірко
О.В. Юровський
О.М. Воскресенська
О.О. Скрипальова
О.Ю. Коваленко
П.О. Сухонос
Ю.В. Артамонов
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2020-04-02
