New Mean Sea Surface CNES_CLS 2015 Focusing on the use of Geodetic Missions of CRYOSAT-2 and JASON-1.

Philippe Schaeffer (CLS, France)


Marie-Isabelle Pujol (CLS, France); Yannice Faugère (CLS, France); Amandine Guillot (CNES, France); Nicolas Picot (CNES, France)

Event: 2016 Ocean Surface Topography Science Team Meeting

Session: The Geoid, Mean Sea Surfaces and Mean Dynamic Topography

Presentation type: Type Oral

A new mean sea surface (MSS) has been determined focusing on the accuracy along Exact Repeat Mission profiles and also Geodetic Mission, in order to offer a centimetric level of precision.
Particular attention was paid to the homogeneity of the ocean content of this MSS, and specific processings were also carried out on data from geodetic missions. For instance, CryoSat-2, Jason-1 GM, and ERS-1 GM data were corrected from oceanic variability using results of optimal analysis of sea level anomalies (SLA).
A new specific data processing was used near the coast, the aim has been to preserve better continuity of the MSS accuracy from the open ocean to the coasts compared to the former versions of MSS.
This MSS CNES_CLS 2015 is referenced to the 20 years of T/P/Jason-1/Jason-2 mean profile (1993-2012).
The MSS has been determined using a local least square collocation technique which provides an estimation of calibrated error. Our technique takes into account of altimetric noise, ocean variability noise and also along-track biases which are determined independently for each observation. Moreover, variable cross-covariance models are fitted locally for a more precise determination of the shortest wavelengths lower than 50 km.
The CNES_CLS 2015 MSS can thus be used for cal/val activities for Jason-3 and Sentinel-3, and especially for computation of SLA for DUACS project which include data of drifting missions. Goal was also a first step to access to shortest wavelengths in preparation of very high resolution topographic surface for the upcoming mission such as SWOT.

Oral presentation show times:

RoomStart DateEnd Date
Richelieu Wed, Nov 02 2016,16:55 Wed, Nov 02 2016,17:15
Philippe Schaeffer