Routine Shipboard Marine X-Band Radar Near-Surface Current Mapping: Insights from Two Research Cruises

Dedicated science marine X-band radar (MR) systems onboard research vessels can complement the navigation radars by providing routine time series of surface wave parameters and near-surface currents as well as surface wave frequency-direction spectra. This study demonstrates how shipboard MR measurements can also be used to routinely retrieve near-surface current maps with high spatio-temporal resolution. The current maps are based on backscatter intensity image sequences acquired by a coherent-on-receive MR developed at Helmholtz Zentrum Geesthacht, Germany. Example results from two recent research cruises in the Pacific Ocean near Taiwan and off the coast of California are presented, showing energetic submesoscale upper ocean flow dynamics. The MR near-surface current maps are presented in conjunction with backscatter intensity images, which allow an indirect validation of the observed near-surface processes.