Summary of Abstract Submission

Abstract Submission No. IO50-04-0036PresentationPoster

CHARACTERISTICS, VERTICAL STRUCTURES AND HEAT/SALT TRANSPORTS OF MESOSCALE EDDIES IN THE SOUTHEASTERN TROPICAL INDIAN OCEAN

Guang Yang*1, Weidong Yu1, Yeli Yuan1

1 First Institute of Oceanography, State Oceanic Administration, China

ABSTRACT :

The satellite altimetry sea surface height measurement captures strong mesoscale eddy activity in the southeastern tropical Indian Ocean (SETIO). In this study, characteristics of mesoscale eddies in the SETIO are investigated by analyzing 415 cyclonic eddy (CE) tracks and 555 anticyclonic eddy (AE) tracks identified in 20-year altimetry data. The mean radius, lifespan, propagation speed and distance of CEs (AEs) are 148 (148) km, 9.8 (9) weeks, 12.3 (12.9) cm s-1, and 654 (621) km, respectively. The normalized temporal evolution shows three different stages during an eddy┐s lifespan. The first 2/5 is rapid growth, the middle 1/5 is a relatively stable stage, and the last 2/5 is its decaying period. Mean vertical structures of the anomalies of potential temperature, salinity, and geostrophic current, and heat and salt transports induced by the composite eddy are reconstructed by matching Argo data profiles to altimeter-detected eddies. The composite analysis shows that eddy-induced ocean anomalies are mainly confined in the upper 400 dbar. In the eddy core, CEs (AEs) could induce a cooling (warming) of 1.5║C in between 40-180 dbar and positive (negative) salinity anomalies of 0.2 psu in the upper 200 dbar. The total meridional heat transports induced by these CEs and AEs are both northward, whereas the total meridional salt transport of CEs (AEs) is northward (southward).