Recovery of Near-Surface Velocity from Undrogued Drifters

Abstract

Abstract The authors have quality controlled six global datasets of drifting buoy data, made comparisons of 15-m drogued and undrogued buoy observations, and developed a 2D linear regression model of the difference between drogued and undrogued drifter velocity as a function of wind. The data were acquired from 2334 Surface Velocity Program (SVP) drifters, including 1845 SVP drifters after they lost their drogues; 704 AN/WSQ-6 Navy drifter buoys; and 503 First Global GARP Experiment (FGGE) drifter buoys. Meridional and zonal surface wind velocity components from the global synoptic FNMOC model, the global synoptic ECMWF model, and the global synoptic NCEP model were interpolated to naval AN/WSQ-6, WOCE–TOGA buoy, or FGGE buoy positions and date/times in the datasets. Two-day mean buoy drift velocities and positions were computed: 122 101 SVP drifter mean velocities before they lost their drogues and 58 201 SVP drifter mean velocities after they lost their drogues, 21 799 Navy drifter mean velocities, and ...