Satellite Remote Sensing of Submesoscale Fronts in Inner Seas

摘要

The work studies submesoscale fronts (with characteristic transverse scales lower than the Rossby internal radius of deformation) in inland seas on the base of remote sensing data. We show that we can significantly broaden our insights into the physics and geography of small-scale fronts by employing satellite synthetic aperture radar (SAR). During our satellite survey of the Baltic Sea, we obtained many satellite images of the sea surface bearing imprints of fronts of different formation mechanisms and different spatial and temporal characteristics. First we develop a methodology for identifying various submesoscale front signatures in SAR images and list the most common features of front manifestations. We describe characteristic features associated with fronts of different nature which are not usually detectable by traditional observational data sources because of their small scale and because they are often masked by upper-level clouds. The main problem is to discriminate between signatures of fronts in the sea and those in the near-surface layer of the atmosphere. We validated our interpretations of front features in SAR images via the combined analysis of data on the sea surface and marine atmosphere condition, sea surface temperature, and mesoscale water dynamics.