Global submesoscale diagnosis using along-track satellite altimetry

Abstract. The ocean's sea surface height (SSH) field is a complex mix of motions in geostrophic balance and unbalanced including high-frequency tides, internal gravity waves. Barotropic tides are well estimated for altimetric SSH the open ocean, but signals remain. transition scale, Lt, at which these ageostrophic dominate balanced first time using satellite altimetry. Lt critical to define spatial scales above currents can be inferred from gradients. We use statistical approach based on analysis 1 Hz wavenumber spectra obtain four geophysical parameters that vary regionally seasonally: background error, spectral slope mesoscale range, second smaller scales, Lt. error levels similar previous studies break flatter only midlatitude regions where signal exceeds noise level. Small values observed energetic activity, while larger towards low latitudes lower activity. These results consistent with recent analyses situ observations high-resolution models. Limitations our implications reprocessed nadir future swath missions discussed.