HR: 0800h
AN: SF31A-0707    [Abstracts]
TI: Real-Time Access to Altimetry and Operational Oceanography Products via OPeNDAP/LAS Technologies : the Example of Aviso, Mercator and Mersea Projects
AU: * Baudel, S
EM: baudel@cls.fr
AF: CLS, 8-10 rue Hermes, Ramonville-saint-agn, 31526 France
AU: Blanc, F
EM: blanc@cls.fr
AF: CLS, 8-10 rue Hermes, Ramonville-saint-agn, 31526 France
AU: Jolibois, T
EM: jolibois@cls.fr
AF: Coframi, 97 rue Riquet, Toulouse, 31000 France
AU: Rosmorduc, V
EM: rosmorduc@cls.fr
AF: CLS, 8-10 rue Hermes, Ramonville-saint-agn, 31526 France
AB: The Products and Services (P&S) department in the Space Oceanography Division at CLS is in charge of diffusing and promoting altimetry and operational oceanography data. P&S is so involved in Aviso satellite altimetry project, in Mercator ocean operational forecasting system, and in the European Godae /Mersea ocean portal. Aiming to a standardisation and a common vision and management of all these ocean data, these projects led to the implementation of several OPeNDAP/LAS Internet servers. OPeNDAP allows the user to extract via a client software (like IDL, Matlab or Ferret) the data he is interested in and only this data, avoiding him to download full information files. OPeNDAP allows to extract a geographic area, a period time, an oceanic variable, and an output format. LAS is an OPeNDAP data access web server whose special feature consists in the facility for unify in a single vision the access to multiple types of data from distributed data sources. The LAS can make requests to different remote OPeNDAP servers. This enables to make comparisons or statistics upon several different data types. Aviso is the CNES/CLS service which distributes altimetry products since 1993. The Aviso LAS distributes several Ssalto/Duacs altimetry products such as delayed and near-real time mean sea level anomaly, absolute dynamic topography, absolute geostrophic velocities, gridded significant wave height and gridded wind speed modulus. Mercator-Ocean is a French operational oceanography centre which distributes its products by several means among them LAS/OPeNDAP servers as part of Mercator Mersea-strand1 contribution. 3D ocean description (temperature, salinity, current and other oceanic variables) of the North Atlantic and Mediterranean are real-time available and weekly updated. LAS special feature consisting in the possibility of making requests to several remote data centres with same OPeNDAP configurations particularly fitted to Mersea strand-1 problematics. This European project (June 2003 to June 2004) sponsored by the European Commission was the first experience of an integrated operational oceanography project. The objective was the assessment of several existing operational in situ and satellite monitoring and numerical forecasting systems for the future elaboration (Mersea Integrated Project, 2004-2008) of an integrated system able to deliver, operationally, information products (physical, chemical, biological) towards end-users in several domains related to environment, security and safety. Five forecasting ocean models with data assimilation coming from operational in situ or satellite data centres, have been intercompared. The main difficulty of this LAS implementation has lied in the ocean model metrics definition and a common file format adoption which forced the model teams to produce the same datasets in the same formats (NetCDF, COARDS/CF convention). Notice that this was a pioneer approach and that it has been adopted by Godae standards (see F. Blanc's paper in this session). Going on these web technologies implementation and entering a more user-oriented issue, perspectives deal with the implementation of a Map Server, a GIS opensource server which will communicate with the OPeNDAP server. The Map server will be able to manipulate simultaneously raster and vector multidisciplinary remote data. The aim is to construct a full complete web oceanic data distribution service. The projects in which we are involved allow us to progress towards that.
UR: http://www.cls.fr/html/oceano/general/applications/welcome_en.html
DE: 9820 Techniques applicable in three or more fields
DE: 3337 Numerical modeling and data assimilation
DE: 4255 Numerical modeling
SC: Special Focus: Advances in Data Acquisition, Management, Analysis and Display [SF]
MN: 2004 AGU Fall Meeting