Estimation of Spatial Covariances From the Mid-Ocean Dynamics Experiment

The Mid-Ocean Dynamics Experiment (MODE) was an attempt to observe mesoscale ocean eddies in the western North Atlantic, primarily during the spring of 1973. A variety of measurement techniques were utilized. Using data from freely drifting Sofar floats and from hydrographic casts, the authors estimated the spatial covariance functions and the associated variance spectra. To make these functions physically acceptable, they performed smoothing by averaging in wave-number space; azimuthal averages of these smoothed functions yielded estimates of isotropic covariances. Finally, they fitted analytic functional forms to the isotropic covariances for subsequent use in objective analyses.