θ-S relationships and water masses in the eastern North Atlantic

Abstract

Observations of temperature and salinity from IGY and Erika Dan sections in the eastern North Atlantic have been re-examined to identify the θ-S relationships of the water masses and the fronts which separate them, using charts of salinity at potential temperature surfaces and sections of salinity at potential temperature levels. In the Deep Water ( θ ⪕ 4.0°C) four water masses are identified: Mediterranean Water, Labrador Sea Water, Iceland-Scotland Overflow Water, and Bottom Water. In the Intermediate Water (4.0°C < θ < 12.0°C) ee water masses are identified: Sub-Arctic Intermediate Water, Eastern North Atlantic Water (ENAW), and Mediterranean Water; the first two are separated by the Polar Front, whilst a fairly marked sub-surface front separates the latter two. A standard θ-S relationship is presented for ENAW, together with salinity anomalies from this for four zonal sections to illustrate the distributions of the intermediate water masses. The formation of ENAW is considered in relation to winter temperatures and salinities at the surface in the eastern North Atlantic.