IMIS

For decades, satellite altimetry is providing reliable data on the sea level, surface currents, tides, planetary and wind waves and sea ice. We propose a potential enhancement of collecting special data subsets for a better temporal and spatial sampling of dynamics of the Sub-Polar seas. We show that peculiarities of the orbits of the TOPEX/Poseidon and Jasons’ missions generate a regular grid of crossovers which locations are fixed in space and time of the orbit cycles. Two types of these special crossovers are specified: self-crossovers (SC) occurring as intersections of tracks of the same satellite and inter-crossovers (IC) appearing during the phases of interleaved orbits when tracks of two different satellites are crossing. The time delay between two consecutive measurements in the high-latitude sites is less than 2 h for SC and 1 h for IC, thus providing a ground for monitoring large-scale currents (including current direction) and wind waves. The sets of the special crossovers can be regarded as networks of virtual ocean buoys. The Norwegian Sea case study illustrates the value of the special crossovers for the Sub-Polar seas and the feasibility of building the networks of SC and IC in other areas of the World Ocean.