Subsurface temperature maximum in a stratified estuary

A subsurface temperature maximum recorded in the highly stratified Krka Estuary is described. The maximum is located on the lower edge of a steep halocline and reaches the highest temperature in the Adriatic Sea. Temperatures of up to 31 °C were recorded. The development of the maximum and its persistence during summer is the consequence of a relatively thin and transparent brackish water layer while the entrainment of the seawater is weak. The maximum may be recorded from the middle of April until the end of October.