Deliverables

D2.1 - Design of the OSSEs with multi-platform in situ data and impact on fine-scale structures

Work Package:
WP2

Lead Beneficary:
CSIC

Publication Date:
10/2020

Executive Summary

Deliverable 2.1 provides a detailed description of the design of the Observing System Simulation Experiments (OSSEs) planned to be conducted in Task 2.3 of the EuroSea project. The objective of these OSSEs is to improve the design of multi-platform experiments aimed to validate the Surface Water and Ocean Topography (SWOT) satellite observations with the goal to optimize the utility of these observing platforms. The SWOT mission will be launched in 2022 and is considered a big breakthrough in Earth observation as it is expected to have a spatial resolution one order of magnitude higher than present altimeter.

In Task 2.3 we plan to evaluate different configurations of the in situ observing system through OSSEs, including rosette and underway CTD, shipborne ADCP, velocities from surface drifters, and Argo vertical profiles, together with conventional satellite nadir altimetry. The observations from these platforms will be simulated from high-resolution models that will be considered the ocean “truth”. Several methods of reconstruction will be tested to reconstruct the simulated observations, including new algorithms based on machine-learning techniques. The capacity of the reconstructed fields to represent the sea level and surface current variability of the models considered the ocean “truth” will be evaluated considering the different configurations of the in situ observations. The analysis will focus on two regions of interest for the Climate Demonstrator in WP7: (i) the western Mediterranean Sea and (ii) the Subpolar North West Atlantic.

Deliverable 2.1 starts describing the motivation and objective of Task 2.3 of the EuroSea project. Then, we divide the main objective in different scientific goals and subtasks. The first goal is to optimize the design of a multi-platform in situ experiment to validate SWOT, the second goal is to compare different methods of reconstruction to validate simulated observations of SWOT, and the third goal is to explore the capability of the existing observing system networks to validate SWOT. In Section 5 we describe the design of the OSSEs that will be conducted to achieve these goals: regions of study, high-resolution models to be used, observations planned to be simulated, different configurations that will be evaluated, methods of reconstruction to be tested, and analysis of the results. We finalise the Deliverable with a work plan and conclusions.

Deliverable Report https://doi.org/10.3289/eurosea_d2.1

D2.2 - Analysis of the physical and BGC design experiments

Work Package:
WP2

Lead Beneficary:
MOI

Publication Date:
03/2022

Executive Summary

The task objective is to assess the role of the in situ networks and their future extension at improving the accuracy of future global CMEMS physical and BGC analysis and forecasting system.

Data assimilation experiments for the physical in situ observations will focus on the impact of the increased density of floats in specific regions, as planned in the Argo-2030 project. The impact of such extensions was assessed at global scale on the analysis. The experiments were conducted with the future improved version of the CMEMS global operational system. Another aspect explored here is the complementarity between the satellite observing component and the in situ one in constraining the different scales of the ocean circulation.

Concerning the BGC in situ observations, comparison to the BGC Argo floats helps to identify regions with a lack of observations or large model error that should benefit from an increased number of BGC Argo floats. Thanks to the BGC model, key regions for the export of organic carbon were also identified.

Deliverable Report https://doi.org/10.3289/eurosea_d2.2

D2.3 - Analysis of the OSSEs with multi-platform in situ data and impact on fine-scale structures

Work Package:
WP2

Lead Beneficary:
CSIC

Publication Date:
07/2022

Executive Summary

Deliverable 2.3 describes the study developed in Task 2.3 of the EuroSea project. It includes recommendations for the design of in situ experiments aimed to reconstruct fine-scale ocean currents (~20 km), such as those that will be conducted to validate SWOT satellite observations. An advanced version of the spatial optimal interpolation used in field experiments, which also includes the temporal variability of the observations, has been applied to evaluate different sampling strategies.

Our results show that in the Mediterranean and Atlantic study regions distinct strategies provide reconstructions similar to the ocean truth, especially those consisting of rosette Conductivity Temperature Depth (CTD) casts down to 1000 m and separated by a range of distances between 5 and 15 km. A good compromise considering the advantages of each configuration is the reference design, consisting of CTD casts down to 1000 m and 10 km apart. Two faster alternative strategies in the Mediterranean comprise: (i) CTD casts down to 500 m and separated by 10 km and (ii) an underway CTD with a horizontal spacing between profiles of 6 km and a vertical extension of 500 m. Concerning seasonality, the reference configuration is a design that provides reconstructions similar to the ocean truth in both regions for the period evaluated in summer and also in winter in the Mediterranean. We have tested two additional reconstruction methods in the Mediterranean. A technique based on machine learning shows a slight improvement with respect to the spatial optimal interpolation. Another method based on model data assimilation shows that the experiments including CTD pseudoobservations provide better reconstructions of temperature and salinity than the experiment with no data assimilation or only assimilating satellite pseudo-observations. Finally, we have evaluated the recently developed MIOST technique to map nadir altimetry using current observations derived from drifters. Maps constructed through this technique show improvements in energetic regions such as the Algerian current; this will be a useful technique for SWOT validation.

Deliverable Report https://doi.org/10.3289/eurosea_d2.3

D2.4 - Development of targeted indicators and their uncertainties for demonstrators and Forecasts

Work Package:
WP2

Lead Beneficary:
ENS

Publication Date:
12/2022

Executive Summary

Indicators can provide information to guide sustainable management. They are necessary for regular reporting on the state of the ocean, its variability and change. Indicators can also be used to identify knowledge gaps and observing system gaps that limit our capacity to respond to society’s needs for ocean information and thus serve as useful guides to prioritize investments in the observing system. They are also key communication tools for the general public, enhancing ocean literacy and the engagement of citizens in the global effort. Indicators can apply both to the state of the marine environment and to considerations of performance against environmental targets and/or limits in a defined geographical area. In order to guide management, indicators should be set within a reference framework and hierarchies of indicators can provide coordinated support.

Through this deliverable, the EuroSea project seeks to improve existing climate and marine indicators via a co-development process with stakeholders involved in different sectors represented by the project’s different Working Packages (WP2 “Ocean Observing System Design”, WP4 “Data integration, assimilation and forecasting“, WP5 “Coastal resilience and operational services demonstrator“, WP6 “Ocean Health Demonstrator” and WP7 “Ocean climate indicators demonstrator”). In this, we took into account requirements for important end-users and stakeholders key for different sectors (governments, regulatory bodies, intergovernmental frameworks, fisheries, aquaculture, ocean energy, coastal and port managers, marine research and the public) and interested in assessments at different scales (from that of an entire ocean basin or sea to scales of bays, aquaculture farms, harbours and beaches). This work will provide direct economic benefits and follow-on opportunities in services for countries and industries depending on ocean health and long-term forecasts of weather and climate.

The deliverable presents the process we undertook to co-define scientifically based indicators as well as the requirements in terms of Essential Ocean and Climate Variables (EOVs/ECVs) linked with them for each group of stakeholders included in EuroSea Demonstrators (WP5–7) and Forecast (WP4) working packages. This necessarily also defines the requirements in terms of observations and platforms.

Deliverable Report https://doi.org/10.3289/eurosea_d2.4

D2.1 - Design of the OSSEs with multi-platform in situ data and impact on fine-scale structures

D2.2 - Analysis of the physical and BGC design experiments

D2.3 - Analysis of the OSSEs with multi-platform in situ data and impact on fine-scale structures

D2.4 - Development of targeted indicators and their uncertainties for demonstrators and Forecasts

The EuroSea ended in December 2023. This website will no longer be updated from January 2024.