Intercomparison of an ADCP, ADP, standard and long-range HF radar: influence of horizontal and vertical shear

A nested HF radar network has been deployed along the New Jersey coast as part of the New Jersey Shelf Observing System (NJSOS). A standard range (about 50 km) system setup for continuous operation since 1999 includes two sites in Brant Beach and Brigantine, New Jersey. A second longer range system (about 170 km) includes four New Jersey sites set up in Wildwood, Tuckerton, Loveladies, and Sandy Hook. The first of the long-range sites was deployed in Spring 2000. Both the long-range and standard-range systems provide real-time maps of surface currents, with resolutions of 1.5 km (standard) and 6 km (long-range). During the summer of 2001, three Workhorse ADCPs and two SonTek ADPs were deployed along a line perpendicular to the coast. All of these in situ current meters were deployed for six weeks within the footprints of the two CODAR networks. Comparisons were made between the ADCP/ADP time series and radial CODAR time series provided by the long-range and standard-range sites closest to the line of current meters. Additional comparisons were drawn between the total current fields of the standard and long-range CODAR systems with the in situ current meters. Several forcings were examined to explain the differences in the observations including vertical and horizontal shears.