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Information × Registration Number 0211U013047, 0111U009940 , R & D reports Title Research of seasonal and interannual variability of hydrometeorological characteristics in surface layer of Southern ocean and their connection with global processes in ocean-atmosphere system. popup.stage_title Head Polosky Alexander Borisovich, Registration Date 10-01-2012 Organization Marine Hydrophysical Institute NAS of Ukraine popup.description2 On the basis of modern climatic dataset, archived bases of the contact hydrological data and long-term re-analysis data the seasonal and interannual variability of temperature fronts characteristics and the water masses areas in Antarctic peninsula region is investigated. The variability of thermal balance on the ocean and continent and its components in Antarctica region on temporary scales from interannual to inter-ten-years' is investigated. Quantitative characteristics of interannual variability and trends of ice boundary position at Southern ocean are received. It is shown that the maximum seasonal variability with a prevailing annual signal is characteristic for intensity of South Subtropical (SSbTF), Subantarctic (SAF) and Antarctic Polar (APF) fronts. SSbTF and SAF are intensified mainly in the warm season of Southern hemisphere (February-April), and APF - in cold (September-October). It is shown that regional hydrometeorological and orographical features to the west and the east from Antarctic Peninsula influence interannual variability of fronts. As a result of estimates of the front's characteristics linear trends during 1982-2008 for each month of year it is revealed that in Bellinsghauzen Sea the Antarctic polar front weakens in all months. In Scotia Sea APF weakening more all is appreciable for summer of Southern hemisphere whereas in spring the magnification of front intensity is observed. APF intensity almost for all months increases in Drake Passage. Small decrease of front intensity is observed only in winter (July-August) and in the end of spring (November). The Subantarctic front in Scotia Sea considerably intensifies in summer of Southern hemisphere. SAF weakening on interannual scale is founded in the end of winters (August). The South Subtropical front to the west from Antarctic Peninsula weakens in the summer and winter of Southern hemisphere and becomes intensified in the spring and in the autumn. Estimates of trends of temperature on front axis have shown that for APF in all months temperature increase in Drake Passage and its decrease in Bellinsghauzen Sea is observed. In Scotia Sea trends of APF temperature basically are insignificant, only for January SST decreasing is observed. Temperature trends of SAF in Scotia Sea are positive for all months. For SSbTF the area of SST trends high values is observed in east part of Pacific ocean where they reach the maximum positive values for July and negative for December. The analysis of front's latitude positions trends has revealed a tendency to APF shift for last 27 years on the north in Drake Passage both in Scotia Sea and on the south in Bellinsghauzen Sea. On the basis of archived base WOD-2009 and climatic array WOA-2009 the seasonal variability of Antarctic winter (AWW) and Antarctic intermediate (AImW) water masses is analysed in Drake Passage on sections from surface to depth of 200 m. Shown that the greatest AWW areas are observed in September-October, after the terminal surface water cooling. The maximum of AImW is marked in March-April, in the end of the period of surface water salinity decrease at the expense of intensive precipitates and ices melting. The analysis of climatic intraannual and interannual changes of the water masses squares in the SST field for different temperature diapasons in Antarctic Peninsula region is made used NCEP data from 1982 for 2009. It is shown that the maximal seasonal and interannual variability of the water masses squares is observed in the ocean regions between large-scale fronts, and SST field - in zones of fronts: South Subtropical, Subantarctic, Antarctic Polar and Front of the South branch of Antarctic Circumpolar current (АCC). The conformity of water masses squares seasonal variability and intraannual latitude displacement of large-scale fronts is revealed. It is shown that on seasonal and interannual scales of magnification of the water areas which are located to the south of Front of the South branch of Antarctic Circumpolar current, and between Antarctic Polar and Subantarctic fronts it is accompanied by reduction of the waters area between Front of South branch АCC and the Antarctic Polar front. The variability of thermal balance on the surface and continent and ocean and its components on temporary scales from interannual to inter-ten-years' in Southern hemisphere is investigated used re-analysis NCEP/NCAR data during 1950-2001. On monthly averaged data of short-wave and long-wave radiation on spreading surface and sensible and latent heat flux from re-analysis NCEP/NCAR the radiation balance and the full thermal balance have been calculated on surfaces of the Earth. The main regularities in climatic values spatial distribution are confirmed. Radiation balance distribution has zonal character, the sensible and latent heat flux maximal values are observed in activity zones of atmosphere and ocean interaction. The greatest values of the sensible and latent heat flux are observed in the summer in Southern Atlantic Ocean. It is shown that the linear trends values of thermal balance and its components basically are not significant. At the same time, there are significant quadratic trends which specify in presence of low-frequency variability. In thermal balance components variability for some energy active areas of Southern ocean connection with the Pacific Decadal Oscillation phases is revealed. It is obtained that interannual-inter-ten-years' variability of thermal balance is caused preferentially by variability of the sensible and latent heat flux. The appreciable contribution of radiation balance variability is observed only in winter in Antarctic region. On the continents thermal balance variability essentially more low, than at ocean that confirms an important role of ocean in climate changes. On the basis of the monthly averaged sensible heat flux data from re-analysis NCEP the trends of ice boundary displacement in Pacific and Indian sectors of Southern ocean for periods 1950-2001 and 1981-2001 (winter season) are investigated. It is necessary that the boundary between areas of positive and negative turbulent heat flux through an ocean surface indirectly specifies the standing of boundary of high ice closeness. It is shown that trend received at average on the Indian sector of Southern ocean is positive (displacement toward equator) and makes 0.016°latitude/year, but its significant level does not exceed 85%. In the Pacific part of Southern ocean the ice boundary also moves on the average to the north. The average trend for this area (trend value 0.040°latitude/year) is significant at 95% level. New knowledge about the climate changes mechanisms on regional and global scales, obtained in result of the conducted researches, 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 popup.authors popup.nrat_date 2020-04-02 Close