CTOH altimetry products (L1 to L4) for ocean and continental surfaces applications

Sara Fleury (LEGOS, France)

CoAuthors

Florence Birol (LEGOS, France); Denis Blumstein (LEGOS, France); Fernando Niño (LEGOS, France); Nicolas Fuller (LEGOS, France); Marine Rogé (LEGOS, France); Rosemary Morrow (LEGOS, France); Fabien Blarel (LEGOS, France); Benoit Legresy (LEGOS, France); Frédéric Frappart (LEGOS, France)

Event: 2014 Ocean Surface Topography Science Team Meeting

Session: Outreach, Education and Altimetric Data Services

Presentation type: Type Poster

CTOH altimetry products (L1 to L4) for ocean and continental surfaces applications

S. Fleury, F. Birol, F. Blarel, D. Blumstein, F. Frappart, B. Legresy, R. Morrow, F. Niño, M. Rogé

The Center for Topography of the Oceans and Hydrosphere (CTOH) is a French Observation Service created in 1989 and dedicated to satellite altimetry studies. Its objectives are to 1) maintain and distribute homogeneous altimetric databases for ocean, hydrosphere and cryosphere applications, 2) help scientific users to develop new altimetry derived products and 3) contribute to the development and validation of new processing approaches of the altimetric data for emerging research domains (coastal ocean, continental surface water monitoring, cryosphere, ...).


The CTOH maintains homogeneous altimetric GDR data bases for the following missions : Topex/Poseidon ; ENVISAT ; Jason-1; Jason-2 ; Saral/Altika ; Cryosat2. A very new version of ERS-2 reprocessed data, including both ICE-1 and ICE-2 retrackers and all the usuall corrections is now available (see posters by Niño et al. and Legresy et al.)


Both 1Hz and 10-20-40Hz data are available over all possible oceanic and continental surfaces. Waveforms are also avaible for some altimeter missions. We also add about 20 recent altimetry corrections and auxiliary parameters in a homogeneous way to all GDRs. It includes tide models, DAC, MSS, geoids, and tropospheric corrections. Except for T/P mission, all these products are provided in netcdf format


In addition, the CTOH works on developing new altimetric products :

• Coastal products : Along-track SLA time series are available in 23 different regions, computed with the X-TRACK software designed for coastal altimetry processing (…/products/coastal-products). SLA are available on a nominal groundtrack (1hz and 10-20hz for some regions), for all precise altimeter missions (Topex/Poseidon, Jason-1&2, Geosat Follow on and Envisat). A regional product of along-track tidal harmonic constants (including the amplitude, phase lag and error estimates for a number of tidal constituents), computed by harmonic analysis of X-TRACK 1-Hz SLA, is also available (see poster by Fűller et al.).

• Continental hydrology products : including the “Hydroweb” data base for monitoring river and lake levels (…/products/hydroweb). Hydroweb now integrates the CASH project: Topex reprocessed data over terrestrial surface waters.

• Global SubMesoscale filaments. Amplitude and position of sub-mesoscale filament barriers calculated from gridded AVISO surface currents using the Finite-Size Lyapunov Elements (d’Ovidio et al., 2009), at 4 km resolution from 1993 to today (…/products/submesoscale-filaments).

• Advection products: advection fields are computed from AVISO surface currents. They allow to simulate submesoscale phenomenon on large-scale tracer fields (see dedicated poster).

All these products are now progressivelly re-distributed via AVISO+, our new common platform with AVISO: http://www.aviso.altimetry.fr/en/home.html.

More informations can be found on the CTOH website http://ctoh.legos.obs-mip.fr/.
 
Sara Fleury
LEGOS
France
sara.fleury@legos.obs-mip.fr