Session: Ocean III

The ESA CryoSat mission is the first space mission to carry a radar altimeter that can operate in Synthetic Aperture Radar (SAR) mode. It thus provides the first opportunity to test and evaluate, using real data, the significant potential benefits of SAR altimetry for ocean applications.

The objective of the CryoSat Plus for Oceans (CP4O) project was to develop and evaluate new ocean products from CryoSat data and so maximize the scientific return of CryoSat over oceans.  The main focus of CP4O has been on the additional measurement capabilities that are offered by the SAR mode of the SIRAL altimeter, with further work in developing improved geophysical corrections.

CP4O has developed SAR based ocean products for application in four themes: Open Oceans, Coastal Oceans, Polar Oceans and Sea Floor Topography.  The team has developed a number of new processing schemes and compared and evaluated the resultant data products.  This work has clearly demonstrated the improved ocean measuring capability offered by SAR mode altimetry and has also added significantly to our understanding of the issues around the processing and interpretation of SAR altimeter echoes.

This paper presents an overview of the major results and outlines a proposed roadmap for the further development and exploitation of these results in operational and scientific applications, with particular focus on their relevance for Sentinel-3.

The “CryoSat Plus for Oceans” (CP4O) project has been supported by ESA (Support To Science Element) and CNES.

We perform an investigation into the retrieval of sea surface height in the Arctic Ocean using the DTU LARS (LARS advanced retracking system) containing 12 physical and empirical retrackers to evaluate the determination of seasonal sea level in the Arctic Ocean from satellite altimetry.

Physical retrackers assume a uniform probability density function for the waveheight within the footprint which is frequently compromised in the Arctic Ocean due to the presence of seasonal sea ice and the period of initial freezing of the ocean. This has the effect of lowering the theoretical (open ocean) sea state. 

Prelinimary investigations highlight the pros of the empirical retrackers for seasonal sea ice covered regions as it does not assume anything about physical properties and the pros of a physical retracker for either permanent near fully icecovered or open ocean.

 Comparison with both tide gauges and conventional altimetry is performed in this study to highlight the pros and cons of physical vs empirical retracking in the Arctic Ocean. 

The European Anchovy (Engraulis encrasicolus, Linnaeus, 1758) is one of the most important resources of the Mediterranean Sea. Despite its relevance, the influence of environmental forcing on the anchovy population off the Mediterranean coasts, which exhibits a patchy distribution, is poorly known. We here pursue a pioneering approach that pairs satellite-based observations (i.e., Sea Surface Temperature, Chlorophyll concentration), ichthyoplankton dynamics, and Lagrangian simulations in order to investigate the role of environmental parameters on anchovy larvae fate and distribution. We hypothesize that the environmental conditions along the Lagrangian trajectories may rule the amount and distribution of near-future biomass. Our analysis is based on the Lagrangian connectivity between spawning and recruiting areas within the Sicily Channel and makes use of currently available satellite data. The obtained results are preliminarily compared with in-situ measurements of larval anchovy biomass. Our future intention is to explore the new Sentinel 3 products in order to improve our analysis and refine our hypotheses.

The operational global wave model MFWAM of Météo-France currently assimilates wave data from three altimeters Jason-2, Saral/Altika and Cryosat-2. With the improvements of the last release of the wave model MFWAM in november 2014 and the assimilation system, the wave forecast is among the most accurate regarding to the monthly intercomparison from Joint Commission of Oceanography and Marine Meterology (JCOMM). The next coming altimeter mission Sentinel-3 will provide only wave heights from the SAR processing mode. In order to use such data in operations. impact studies have been performed using the available SAR mode wave data from the altimeter Cryosat-2.
Cryosat-2 SAR-mode data over a period of one year were provided by the french space agency CNES. The assimilation tests with the wave model MFWAM are developed for this period. The results are validated with independent altimeter wave data and buoy data. A comparison with the assimilation of wave data LRM-mode from Cryosat-2 is also examined. Further attention will be taken for the analysis of high sea state events generated by severe storms.

The primary objective of SAFI project (SAFI standing for “Support to Aquaculture and Fishery Industry”) is to exploit Earth Observation (EO) resources to support fishery and aquaculture industries in marine coastal regions.

The service, based on additive value brought by a network of SMEs, is adapted to each category of targeted users.

By making the best use of emerging EO products, the project is aiming at developing services to assist aquaculture deployment (optimization of cages location with respect  to environmental and ecological context) and environmental monitoring during operations as well as supporting fishery by providing indicators of recruitments, abundances, and shell/fish locations (and its variability due to climate change). In this perspective, SAFI fosters the use of the latest generation of satellite sensors and in particular those on-board the future ESA Sentinel missions (Sentinel 2 and 3).

The capacity of exportation and acceptance of the developed services is then evaluated on several pilot sites in Europe (Spain, Portugal, Ireland, France) and demonstrated in Morocco.

Finally, SAFI is also setting up a network of SMEs at different levels of expertise (and EO awareness) required by the service in order to build a consistent and marketable offer.

The project will finally lead to the development, deployment and evaluation of an integrated decision-support tool based on a web-GIS, broadcasting SAFI indicators to the various user concerned (industrials, public administrations in charge of fishery or aquaculture planning, EO service providers, great public) that will be fed by a service of EO high level data processing.

The SAFI project is in progress, reaching its half duration (18 months). An important task of data collection (from in situ sampling) and data collection (from existing database) has been done, that have allowed, thanks to joint exploitation of Ocean Colour, SST and SSH to derive correlations between environmental situation and biological status. The results are synthetic indicators covering the recruitments, abundance and maturation of some species for fishing (either fish or shellfish) as well as for aquaculture. The SAFI system and services would then fully benefit of the upcoming sentinel-3 offer. A dedicated task of adaptation towards Sentinel-3 data is foreseen as soon as data is available.

The most recent results will be presented at the workshop together with the status of their validations.