SCIENCE APPLICATIONS INTERNATIONAL CORP COLLEGE STATION TX
Ice kinematics are described in terms of the 5 basic modes of motion divergence D, vorticity zeta, deformation rate T, and ice translation U. Seasonal time histories of these ice kinematic parameters IKP were calculated using position data from drifting buoys in the arctic during May, Aug, and Nov 1979. Results were used to determine seasonal space and time scales of D, zeta, T, and translation speed variations in the arctic. An e-folding scale is used as a measure of temporal coherency. Spatial variability is defined in terms of the degree of similarity between the magnitudes of a parameter at various locations. Results of seasonal space and time scale analyses indicate that divergence was the most temporally and spatially variable of the IKP for all seasons. Translation speed was the most consistent in space and time. Significant variations in divergence occurred in some areas on the order of 110 km and within approx. 2 hours. In contrast, significant variations in the translation speed occurred in some areas on the order of 705 km and over a period as great as 80 hours. This information is appropriate for setup of numerical simulations of ice motion. The Navys Polar Ice Prediction System PIPS is the only operational system which can furnish predictive ice kinematic information throughout the arctic. To provide useful operational information, PIPS must be run at the appropriate space and time scales.