Identyfikatory
Warianty tytułu
Changes in sea ice cover of the Barents and Greenland seas in the light of changes of the Labrador Current intensity index (1973-1994). Preliminary result of analysis
Języki publikacji
Abstrakty
The Barents and Greenland seas are characterised by great seasonal and interannual changeability in the ice cover. Research carried out by many authors prove that the ice regime of these seas is influenced, to a great extent, by large scalę changes in atmospheric circulation and by the ocean surface circulation of the North Atlantic and the Arctic Ocean. Such correlations arę mainly of teleconnection type and show phase shifts (among others Mysak 1995, Deser et. al. 2000). One of the elements of the sea surface circulation of the Atlantic Ocean is the Labrador Current. The intensity of this current changes in time. In the periods when the Labrador Current becomes strong, its waters form vast anomalies in the sea surface temperaturę in the NW Atlantic. Further they spread eastwards along the north edge of the North Atlantic Current and with some delay, have influence on the atmospheric circulation in the central and east part of the North Atlantic (Marsz 1997, 1999). The way how the changes in the intensity of the Labrador Current influence the climate nas not been discovered yet. The intensity of this current can be defined by means of an index (WPL - Labrador Current Intensity lndex) established by Marsz (Internet). This work examines if there is direct correlatton between the changes in the sea-ice cover of the Barents and Greenland seas and the variability of the intensity index of the Labrador Current. The research madę use of homogenous data concerning a week-old sea ice cover observed at the analysed seas and the values of intensity index of the Labrador Current in the period January 1972 until December 1994 given by Marsz (obtained from NIC and NCDC - Asheville). It has been stated that over the examined 23-year period (1972-1994) the mean monthly the sea-ice cover in the Barents Sea indicates to strong correlation with the changes in the value of the intensity index of the Labrador Current (Table 1, Fig. 1). The changes in WPL result in the rhythm of changes in the sea-ice cover of the Greenland Sea only in winter (Table 2, Fig. 2). The occurrence of anomalies in the sea surface temperatures in the region SE of New Foundland seem to have great influence on the later formation (after few or several months) of the sea-ice cover in the Barents Sea (Fig. 1, 3. 4, formula 1-3). Changes in the intensity of Labrador Current in a given year explain 30% up to 50% changeability of the sea-ice cover developing in that sea from January to July in the following year (Table 1, Fig. 3). The area of the sea-ice cover in the Greenland Sea is mainly influenced by the intensity of the Transpolar Drift and East-Greenland Current transporting considerable amount of ice from the Arctic Ocean. Only during fuli winter season, from January to March, the correlation between the intensity of the Labrador Current and the sea-ice cover reaches statistical significance (Table 2). The results of the carried out analysis point to significant influence of advection factor on the sea-ice cover of the examined seas. In both analysed seas the phenomenon is connected to both the character and intensity of the Atlantic waters flow and to greater frequency of occurrence of specified forms of air circulation in the region of central and eastern part of the North Atlantic, possible at a given distribution of anomalies in surface waters of the North Atlantic.
Czasopismo
Rocznik
Tom
Strony
93--104
Opis fizyczny
Bibliogr. 16 poz., rys., tab.
Twórcy
autor
- Katedra Meteorologii i Oceanografii Nautycznej, Wydział Nawigacyjny WSM w Gdyni, stysa@wsm.gdynia.pl
Bibliografia
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-article-BWM3-0020-0007
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.