An HF-radar test deployment amidst an ADCP array on the West Florida Shelf

For 11 days in January 2002, the Conrad Blucher Institute for Surveying and Science, Texas A&M University-Corpus Christi, in collaboration with the College of Marine Science, University of South Florida, deployed a pair of 25-MHz CODAR Ocean Systems HF-radars on the West Florida Shelf over an array of six acoustic Doppler current profilers. The radar footprint had a maximum range of 60 km offshore, and it included mooring locations between the 10 m to 30 m isobaths. We examine, using a variety of metrics, the correlation between the surface currents measured remotely by the HF-radar and the subsurface currents measured by the ADCPs, which were either bottom- or surface buoy-mounted. Qualitative comparisons are generally good for this inner-shelf environment where the wind-driven current magnitudes were less than about 40 cm/s. The scalar regression analysis shows correlation coefficients (R) of 0.8 to 0.9 for the alongshelf components but 0.6 or less for the cross-shelf components. Complex vector correlation produces correlation values of 0.76 to 0.90 and a consistently clockwise veering from the radar-measured currents to the ADCP-measured ones ranging from 1.3 to 5.2 . The alongshelf surface currents measured by the radar are about 30% larger than those of the ADCPs measured 2 to 3 m below the surface according to standard deviations and linear regression slopes.