Improved Vorticity Balance in Gridded Altimetry Data from Multiple Satellites

Xingliang Jiang1, Lei Liu1, Zhijin Li1, Xiaochun Wang2 and Changming Dong3, (1)University of California Los Angeles, JIFRESSE, Los Angeles, United States, (2)University of California Los Angeles, Los Angeles, CA, United States, (3)University of California, Department of Atmospheric and Oceanic Sciences, Los Angeles, United States
Multiple Satellite altimeters in orbit provide along-track measurements of sea surface height (SSH) that has a resolution of ~ 60 km. However, data need to be mapped to a regular space-time grid for a wide range of scientific analyses. The methodologies that have been used for producing gridded SSH include optimal interpolation (OI) and two-dimensional variational mapping method (2-Dvar). Analyses showed that vorticities in the existing data product are not in desirable balance. The present study proposes new methods to constrain vorticity balance in a 2-Dvar system. The constraint is integrated into the 2-Dvar through the background state and associated error covariance and a weak dynamical constraint based on the quasi-geostrophic vorticity balance equation. We will present the gridded SSH data with improved vorticity balance for East China Sea.