Sep 9, 2017
Today we (SIO and APL crews) tested out releasing and recovering drifters. We released 3 clusters of 9 drifters off the Pismo Beach Pier (see Figs below). All drifters were released by approximately 11:00 and drifted for about 3 hrs. The drifters displaced approximately 3 km in these 3 hours, so the surface current magnitude is |u|~25 cm/s. After deployment, ADCP transects were performed (and numerous whales were spotted). It was a pleasant day and everything went as anticipated. We look forward to the NPS crew joining the fun.
The R/V Sounder made 4 transects running east-west through the drifter clusters, each time observing a similar velocity structure. By coincidence, the drifter release points bracketed a current constrained laterally within the array and vertically to 10 m depth. Very cool feature.
The Nortek Signature profiles collected from the SWIFT drifters are consistent with the center of this velocity signal.