Observing System Evaluation Based on Ocean Data Assimilation and Prediction Systems: On-Going Challenges and a Future Vision for Designing and Supporting Ocean Observational Networks

Yosuke Fujii (1) , Elisabeth Rémy (2) , Hao Zuo (3) , Peter Oke (4) , George Halliwell (5) , Florent Gasparin (2) , Mounir Benkiran (2) , Nora Loose (6, 7) , James Cummings (8) , Jiping Xie (9) , Yan Xue (10) , Shuhei Masuda (11) , Gregory C Smith (12) , Magdalena Balmaseda (3) , Cyril Germineaud (5, 13) , Daniel Lea (14) , Gilles Larnicol (15) , Laurent Bertino (9) , Antonio Bonaduce (16) , Pierre Brasseur (17, 18) , Craig Donlon (19) , Patrick Heimbach (6) , Youngho Kim (20) , Villy Kourafalou (21) , Pierre-Yves Le Traon (2) , Matthew Martin (14) , Shastri Paturi (8) , Benoit Tranchant (15) , Norihisa Usui (1)

1 MRI - Meteorological Research Institute [Tsukuba]
2 Mercator Océan
3 ECMWF - European Centre for Medium-Range Weather Forecasts
4 CISRO Oceans and Atmosphere
5 AOML - NOAA Atlantic Oceanographic and Meteorological Laboratory
6 Oden Institute for Computational Engineering and Sciences
7 UiB - Department of Earth Science [Bergen]
8 NCEP - NOAA National Centers for Environmental Prediction
9 NERSC - Nansen Environmental and Remote Sensing Center [Bergen]
10 CPC - NCEP Climate Prediction Center
11 RIGC - Research Institute for Global Change
12 ECCC - Environment and Climate Change Canada
13 CIMAS - Cooperative Institute for Marine and Atmospheric Studies
14 Met Office Climate Research Division
15 CLS - Collecte Localisation Satellites [Brest]
16 GKSS - Helmholtz-Zentrum Geesthacht
17 IGE - Institut des Géosciences de l’Environnement
18 OSUG - Observatoire des Sciences de l'Univers de Grenoble
19 ESTEC - European Space Research and Technology Centre
20 Ocean Circulation and Climate Research Center
21 Department of Ocean Sciences

This paper summarizes recent efforts on Observing System Evaluation (OS-Eval) by the Ocean Data Assimilation and Prediction (ODAP) communities such as GODAE OceanView and CLIVAR-GSOP. It provides some examples of existing OS-Eval methodologies, and attempts to discuss the potential and limitation of the existing approaches. Observing System Experiment (OSE) studies illustrate the impacts of the severe decrease in the number of TAO buoys during 2012-2014 and TRITON buoys since 2013 on ODAP system performance. Multi-system evaluation of the impacts of assimilating satellite sea surface salinity data based on OSEs has been performed to demonstrate the need to continue and enhance satellite salinity missions. Impacts of underwater gliders have been assessed using Observing System Simulation Experiments (OSSEs) to provide guidance on the effective coordination of the western North Atlantic observing system elements. OSSEs are also being performed under H2020 AtlantOS project with the goal to enhance and optimize the Atlanticin-situnetworks. Potential offuture satellite missions of wide-swath altimetry and surface ocean currents monitoring isexplored through OSSEs and evaluation of Degrees of Freedomfor Signal (DFS). ForecastSensitivity Observation Impacts (FSOI) are routinely evaluated for monitoring the oceanobservation impacts in the US Navy’s ODAP system. Perspectives on the extension ofOS-Eval to coastal regions, the deep ocean, polar regions, coupled data assimilation,and biogeochemical applications are also presented. Basedon the examples above,we identify the limitations of OS-Eval, indicating that themost significant limitation isreduction of robustness and reliability of the results due to their system-dependency.The difficulty of performing evaluation in near real time is also critical. A strategy tomitigate the limitation and to strengthen the impact of evaluations is discussed. Inparticular, we emphasize the importance of collaboration within the ODAP community formulti-system evaluation and of communication with ocean observational communitieson the design of OS-Eval, required resources, and effectivedistribution of the results.Finally, we recommend further developing OS-Eval activities at international level withthe support of the international ODAP (e.g., OceanPredict and CLIVAR-GSOP) andobservational communities.

Domaines: Sciences de l'environnement; Planète et Univers [physics]

Yosuke Fujii, Elisabeth Rémy, Hao Zuo, Peter Oke, George Halliwell, et al.. Observing System Evaluation Based on Ocean Data Assimilation and Prediction Systems: On-Going Challenges and a Future Vision for Designing and Supporting Ocean Observational Networks. Frontiers in Marine Science, 2019, 6, pp.417:1-26. ⟨10.3389/fmars.2019.00417⟩. ⟨hal-02973154⟩