Ocean State Estimation

Ocean State Estimation of the South East Pacific

Aneesh Subramanian

Scripps Institution of Oceanography

University of California, San Diego

ABSTRACT

This research focuses on the mesoscale dynamics of the ocean in the South East Pacific (SEP). Mesoscale eddies generated in the upwelling regions along the west coast of South America, which affect the distribution of sea-surface temper- ature (SST) in the SEP are studied in an ocean data assimilation framework. We propose to study a data assimilated ocean state using ship-based and satellite- based observations of the SEP region, to examine the processes that control the mesoscale variability and its consequent influence on the heat transport and SST distribution over the SEP.

Sea level anomaly (in cm) from AVISO mapped fields in the panel (a) and from the ROMS ocean state estimate in panel (b). The velocities from the model are overlaid on the sea level anomaly contours to reveal cyclonic and anticyclonic eddies.

SST from NOAA Optimally Interpolated observations in top panel and from ROMS in the bottom panel with the model velocities overlaid for 20th Nov, 2008.

The color contours of SLA with the Okubo-Weiss parameter overlaid on top to show eddy like structures.

Eddy Kinetic Energy (EKE) averaged for the first two weeks of November from the model overlaid on the AVISO Sea Level Anomaly (top panel) and ROMS SLA (bottom panel).