The use of simulated drifters to estimate vorticity

A primitive equation ocean model is used to generate trajectories of simula ted clusters of drifters in the California Current (CC) region. These traje ctories allow us to evaluate a least squares (LS) method of estimating vort icity and vertical velocity alone a cluster's path. Two clusters provide ex amples of successful and less successful estimates of vorticity and vertica l velocity. Our analysis quantifies the dependence of estimate quality on s everal parameters that can be used as error predictors in the LS estimate o f vorticity: cluster separation, number of drifters in a cluster, and clust er shape. A combination of cluster separation and ellipticity shows the mos t promise as an indicator of quality for the vorticity estimate. (C) 2001 E lsevier Science B.V. All rights reserved.