Effect of Satellite Spatial Resolution on Submesoscale Variance in Ocean Color and Temperature

Abstract

The capability of moderate-spatial-resolution satellites to accurately resolve submesoscale variations in surface tracers remains an open question, one with relevance to observing physical-biological interactions in the surface ocean. In this study, we address this question by comparing the variance of two tracers, chlorophyll concentration (Chl) and sea surface temperature (SST), resolved by two satellites—MODIS Aqua, with a resolution of 1.5 km, and Landsat 8/9, with a resolution of 30 m. We quantify tracer variance resolved by both satellites on the submesoscale using spatial variance spectral slopes. We find that MODIS measures significantly higher variance compared to Landsat, in both Chl and SST. This is because, despite higher signal-to-noise ratio for MODIS per pixel, Landsat signal-to-noise ratio increases considerably when aggregating pixels. Furthermore, by comparing Chl to SST variance for each satellite we find Landsat to be better match to theory for resolving submesoscale physical-biological interactions.