Illustration of the emerging capabilities of SARAL/AltiKa in the coastal zone using a multiplatform approach

Abstract

© 2014 COSPAR. Published by Elsevier Ltd. All rights reserved. Satellite altimetry measurements from SARALAltiKa are analysed in the coastal ocean using the results of the GAltiKa mission (15 August 2013), which combined altimeter, HF radar and glider data coincident with the satellite track, southwest of Ibiza Island, in the Western Mediterranean Sea. The absolute dynamic topography, computed from 1 Hz and 40 Hz altimetry data, and the dynamic height, computed from glider temperature and salinity, both exhibited a weak signal with amplitudes of order 2 cm. The resulting geostrophic and HF radar velocities along the track depicted a northwestward coastal current with a maximal velocity larger than 20 cm s1. This demonstrates that the AltiKa altimeter is able to resolve SLA signals of more than 2 cm, and gradients in those signals over several tens of kilometres. After filtering, the 40 Hz data depicted a signal consistent with the other platforms, up to a distance of order 10 km from the coast