Search academic texts

Registration Number

0211U007234, 0110U008154 , R & D reports

Title

The researches of interannual variability of hydrometeorological conditions in Antarctic Peninsula region and Atlantic sector of Antarctica.

popup.stage_title

Head

Polonsky Alexander Borysovich,

Registration Date

06-04-2011

Organization

Marine Hydrophysical Institute NAS of Ukraine

popup.description2

On the basis of the most complete archived bases of contact and satellite information and long-term Re-analysis data (archive AVHRR Ocean Pathfіnder Data JPL NOAA/NASA, World Ocean Database-2005, Natіonal Center for Envіronmental Predіctіon, Brіtіsh Atmospherіc Data Centre HadіSST ІCE) the analysis of the spatial-temporal distribution of sea surface temperature (SST) linear trends is carried out in the Antarctic Peninsula region and Atlantic sector of Antarctica and their regional features are described for the different months of year. Seasonal variability of SST trends is discussed in connection with variability of the large-scale wind field. On the basis of the archived dataset the spatial-temporal features of distribution of SST anomalies, heat flux, Antarctic ice boundary are described. The features of seasonal and interannual variability of the polar front's characteristics are refined in the Antarctic Peninsula region, which substantially concerned with the structure and intensity SST anomalies. It is shown, that SST trends distribution in the different months of year specifies on their substantial within-year variability. In polar latitudes most trends are observed in September, at the end of the winter strengthening of the Antarctic Circumpolar Current (ACC). Positive SST trends, probably, is related to the tendency to weakening of ACC speed in a winter period. General research of seasonal variability of SST trends and wind speed components once again confirmed the conclusion done before about influence of surface circulation on SST trends forming. In the most considered cases intensity and direction of winds, indirectly reflecting the drift circulation features on the seasonal scale, is promote accumulation of warm waters in the intensive currents areas on the interannual scale and formation positive SST trends in these zones. It is shown, that in periods of intensive El Nino the anomalous intensification or weakening of fronts, substantial changes of their latitudinal position and phase lag of coming of its intensification maximum is to be observed on the few months. The significant connection between the interannual anomalies of characteristics of Scotia Sea Front in the Drake Passage and Scotia Sea western part and Antarctic Polar front to the west of the Antarctic Peninsula and the areas of warm tropical Pacific waters anomalies, which due to El Nino events. The response of front's characteristics on the South Oscillation Index changes is expressed more poorly, than on the changes of areas of warm Pacific waters anomalies. Research of the spatial-temporal variability of heat flux and Antarctic ice boundary was shown, that the most positive values of sensible and latent heat flux in the investigated region corresponded the of ice boundary zone in winter period. High negative values correspond to areas, by the covered ice. It is shown, that low-frequency variability of sensible and latent heat flux presents ~12% from general variability of monthly sensible and latent heat flux. Maximal standard deviations of sensible and latent heat flux on low frequencies (more than 8 years) are exposed on the ice boundary for period from March for August. The areas of low-frequency variability maximums of sensible and latent heat flux coincide. Most negative trends of sensible and latent heat flux are to be observed on the ice boundary in winter (July-September). For winter season (July-September) from 1981 to 2001 significant on 87% level trend of ice boundary displacement to the north is discovered in the area between 40°W and 20°E, in other parts of the investigated region the trend is not significant on 85% level. New knowledges 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 Peninsula region.

Product Description

popup.authors

popup.nrat_date

2020-04-02