Abstract:

We analyzed and summarized previous research results on water masses in Weddell Sea and its adjacent areas based on data from the Hydrologic Atlas of the Southern Ocean. We further derived potential density (σ)-potential spicity (π) diagrams for water masses analysis in the Weddell Sea. Combined with temperature (θ)-salinity (S) relationships, the formation of different water masses and its relationships are investigated. Repeated observational data from 1989 to 2014 is used to analyze changes of Antarctic Bottom Water (AABW), and the results shows that there have been significant increases in potential temperature and salinity and a distinctive decrease in the area for AABW. Bottom water with temperature below −0.8°C has almost completely disappeared. Temperatures in the warm deep water, deep water and bottom water in Weddell Sea have increased. The warming of bottom water and deep water lags behind that of warm deep water by approximately 5–8 years. The salinities of warm deep water, deep water and bottom water show quasi-decadal oscillations characteristic. Variations in the salinity of deep bottom water are also closely related to those of warm deep water.

Key words: Weddell Sea, warm deep water, bottom water, spicity, shelf water, Antarctic