Calibration procedures and instrumental accuracies for ATLAS wind measurements

We describe calibration procedures and instrumental accuracies for wind speed and direction on Autonomous Temperature Line Acquisition System (ATLAS) buoys deployed in the tropical Pacific and Atlantic Oceans. Accuracy of wind speed measurements over a range of 1 m s−1 to 20 m s−1 is estimated as 0.3 m s−1 or 3% of the speed, whichever is greater. A conservative estimate for root-mean-square (RMS) wind direction error for sensors deployed before November 2000 is 7.8◦, of which 6.8◦ is a mean error in a counterclockwise direction. Beginning in November 2000, wind sensors on ATLAS moorings were modified to correct for this direction bias. Wind direction errors from modified sensors are expected to be reduced to about 5◦ RMS with minimal bias.