Sea Level Anomaly from a multi-altimeter combination in the ice covered Southern Ocean

Matthis Auger (CLS, France)

CoAuthors

Pierre Prandi (CLS, France); Jean-Baptiste Sallée (LOCEAN, France); Amandine Guillot (CNES, France); Gerald Dibarboure (CNES, France); Yannice Faugère (CLS, France)

Event: 2019 Ocean Surface Topography Science Team Meeting

Session: Science Keynotes Session

Presentation type: Type Keynote/invited

For the first time, we construct a gridded Sea Level Anomaly (SLA) product for the open and ice-covered Southern Ocean, based on the combination of high rate measurements from different satellite altimeters.

We benefit from the current constellation using both LRM and SAR data to improve the resolution of SLA fields in ice-covered areas of the ocean. The processing starts from L1b waveforms which are classified using a neural network algorithm to select open ocean and sea-ice leads returns. When possible a dedicated retracking algorithm is used to estimate geophysical parameters, ensuring a processing continuity from the open ocean to ice covered areas. Standard geophysical corrections and a rigorous editing allow to derive valid SLA measurements.

These measurements are mapped on an EASE-2 grid using an objective analysis method. While the mapping is derived from current CMEMS operational processing, its parameters were tuned to match the regional ocean variability.

Daily maps are estimated from 2002 to present, combining measurements from Envisat, Jason-2, Cryosat-2, SARAL/AltiKa, Jason-3 and Sentinel-3A when available. First results suggest that we are able to map ocean features with unprecedented resolution for the region. Comparisons between these maps, the current CMEMS product, GLORYS12 model and previous regional studies are shown. Validation techniques are also discussed.
 

Keynote/invited presentation show times:

Room Start Date End Date
The Forum Mon, Oct 21 2019,15:15 Mon, Oct 21 2019,15:40
Matthis Auger
CLS
France
mauger@groupcls.com