2010 Images of the Month

The radar echo return power of the altimeter enable to keep track of inhomogeneities of surface roughness within the altimeter footprint, since they modify the way the radar waves reflects on the surface, and to reconstruct an "image" from them.

By combining in situ Argo floats and altimetry satellite observation, the heat and salinity transport by eddies is estimated, and the changes of Agulhas eddies as they migrate northwestwards

Comparisons between SAR and Altimetry in open ocean show very good agreement, in particular in the Agulhas current area.

Antarctica is certainly the most inhospitable continent on Earth. Altimetry satellites, however, don't have weather limitations and enable to estimate ice caps topography, including variations from year to year.

Altimetry and operational oceanography models can help nowadays rescues at sea. They can also be used to estimate past ship wreck locations.

Altimetry both benefits from tide models and helps improve them. The tide is indeed one of the strongest geophysical correction of altimetry, with an amplitude of several meters in some regions, like North-East Atlantic, and notably the area between Cotentin Peninsula and Brittany.

The Argonautica educational project aims to help better know the oceans using satellites resources. Different beacons are thus tracked, e.g. on King penguins. The penguins paths are often seen at the edge of the eddies, between a cold and a warm one, especially in the areas where they slow down to feed.

With more and more data from various sources, the mean currents, as seen by the Mean Dynamic Topography are now available with a better resolution.

Altimetry data specifically processed for hydrology enable to monitor the Amazon level, including during the exceptional flood of 2009

Eddies are conveyors of heat and nutrients among other things in the ocean. For a few years now mathematical techniques have been able to track and monitor these features in altimetry datasets, for example in the Gulf of Alaska.

Altimetry enable to compute sea ice thickness from ice freeboard and sea surface height. With such data, the thinning of the Arctic following the record minimum in Arctic sea ice extend of September 2007 is estimated.

The sinking of waters in the depths of the oceans has an impact on sea surface height. The variations of this deep convection can thus be monitored from space by altimetry.