An Intrathermocline Eddy Observed in the Southeastern Tropical Indian Ocean

Abstract

AbstractAn intrathermocline eddy (ITE) was observed over the southeastern tropical Indian Ocean (SETIO) from early February to early May 2020. The ITE was generated near the southwest of Java, and was long lived with a long propagation distance. It had pronounced surface anticyclonic anomalies during westward propagation. Observations from an anchored buoy and several Argo profiles suggested a typical lens‐like vertical structure within the thermocline during the passage of the ITE. The ITE carried a saline water mass with maximum salinity at core depths of 100–150 m. The saline water mass originated from the equatorial Indian Ocean and was transported to the southwest of Java in early January. The formation of the ITE was characterized by a rapid increase of positive sea level anomaly in the southwest of Java, which was closely associated with the local positive wind stress curl in late January and early February.