The Role of the Aleutian Eddies in the Kamchatka Current Warming

K. A. Rogachev and N. V. Shlyk

New oceanographic observations are used for studying the Kamchatka Current and the Alaskan Stream and its Aleutian eddies in 1990–2017. The Aleutian eddies are mesoscale anticyclonic eddies that are formed within the Alaskan Stream southward of the Aleutian Islands between 170 and 180 E and are moving to the southwest. The rapid freshening of the upper layer and the increase in temperature and salinity in the Kamchatka Current halocline are detected. In the upper layer of the Kamchatka Current, salinity decreased by 0.2 psu per 27 years. The most rapid variations in salinity and temperature have been observed in recent years. In the halocline (at the isopycnic of 26.75) temperature rose by 1.4C and salinity increased by 0.15 psu. The maximum temperature of the warm intermediate layer in the Kamchatka Current exceeded 4C for the first time. The most likely reason for the temperature and salinity increase in the halocline is the transport of warm and salt water by the Aleutian eddies.