Multi-scale interactions in ocean circulation analyzed using satellite and in situ observations and model outputs

Nikolai Maximenko (IPRC/SOEST, University of Hawaii, United States)

CoAuthors

Jan Hafner (IPRC/SOEST, University of Hawaii, United States); Per Knudsen (Denmark Technical University, Denmark)

Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)

Session: Salient results from the 2017-2020 OSTST PIs

Presentation type: Type Forum

The project focuses on interactions between mesoscale eddies, striations, and large-scale circulation and, in its life span, produced several important results and products.

Mean Dynamic Topography (MDT) has been refined using the high-resolution geoid model, based on the GOCE mission measurements. Compared to previous products, the new MDT used improved parameterization of ageostrophic currents in drifter data and significantly improved description of the strength, scale, and axis location of major frontal jets.

The improved MDT was used to extract quasi-permanent striations off of California. Low-frequency variations of the orientation of striation axes were compared with changes in propagation velocities of mesoscale eddies and relation of these variations to changes in the large-scale circulation was discussed.

Effects of the mapping procedure on signals of mesoscale eddies in gridded sea level anomaly products was investigated using along-track data. The artificial decay of the eddy amplitude was detected with the increase of the eddy distance from the satellite tracks.

Internal mesoscale eddy dynamics and decay have been studied by analyzing trajectories of SPURS-2 drifters, deployed in the core of one of eddies seasonally generated off of Mexico.

Analysis of close-range interactions between pairs of drifting buoys revealed the ubiquity of mesoscale convergent features in the historical drifter dataset.

Empirical model of surface transport was developed for multiple applications. Simulations of drift of debris from the 2011 tsunami in Japan and their validation using collected reports demonstrated an excellent performance (compared to other models) of the application and provided an insight into the pathways and fate of different types of objects.

The project is in the final year and work continues on finalizing its remaining tasks.
 
Nikolai Maximenko
IPRC/SOEST, University of Hawaii
United States
maximenk@hawaii.edu