Spatiotemporal variability of the thermohaline characteristics of the Mediterranean waters over a section along 36 degrees N
Filyushkin BN, Aleinik DL, Tereshchenkov VP
OCEANOLOGY
43 (3): 318-324 MAY-JUN 2003

Abstract:
The research of spatial and temporary (interannual and seasonal) variability of the thermohaline characteristics of the Mediterranean waters (MW) along a 36degrees N section from 8degrees to 50degrees W was carried out on the basis of 174 hydrographic sections, taken by the weather ships of the Russian Hydrometeorological Service from 1971 to 1985. It is shown that this section is re resentative for the description of the MW propagation to P Z the west (the section coincides with the maximum of the salinity tongue). In order to estimate the interannual and seasonal variability of the water structure, integral characteristics of heat and salt content in a unit water column between 800 and 1500 in at the reference points of the section at 10degrees, 20degrees, 30degrees, and 40degreesW were calculated. It is shown that a positive climatic trend exists at 10degrees W (0.017 psu per year and 0.04degreesC per year). The trend is practically absent at 20degrees W. The negative trend at 30degrees W is low (-0.002 psu per year and -0.009degreesC per year). An analysis of the seasonal variability shows that the fluctuations of heat and salt content occur synchronously at all reference points with the maximum of their values in the spring (March) and at the end of summer (August-September). The amplitude of the fluctuations decreases from east to west, which is determined by the advection of the MW in the western direction. The change in the character of the climatic trend at the reference points of the section allows us to state that the decrease in the MW volume transport from the east to the west results in an increase of the northward flow discharge. Later, these waters are drawn into circulation by the North Atlantic Current at intermediate depths and transported into the Arctic region. This process was observed in 1973-1985.

KeyWords Plus:
ATLANTIC-OCEAN, CIRCULATION