Identification of local upwelling zones in the Bering Sea using hydrochemical parameters

Abstract

Based on the data for the oxygen in the surface layer of the Bering Sea, the areas of pronounced undersaturation (down to 75–80% and below) were distinguished in the surface layer of the Bering Sea. The low percentage values as such of the oxygen saturation might be sustained at the sites of quasi-stationary upwellings. However, in this case, the surface layer should be characterized by decreased temperature and increased salinity as related to the surrounding waters, as well as by increased concentrations of nutrients (phosphates, nitrates, and silicon). The corresponding tests showed that most of the distinguished “patches” of oxygen undersaturation were verified by the oceanological parameters; i.e., these were local upwellings. Some of them were studied quite thoroughly (even with the mechanisms proposed for the formation of steady water lifting), particularly in the area of the Aleutian Islands. However, there are some poorly studied areas (so-called questionable ones) at which the low oxygen content is not confirmed by the hydrochemical parameters (plainly, they are not available); this requires more profound and detailed study.