On the control of spatial and temporal oceanic scales by existing and future observing systems: An observing system simulation experiment approach

Frontiers in Marine Science

Marine Science

Jean-Michael Lellouche¹  Pierre Yves Le Traon¹  Giovanni Ruggiero¹  Elisabeth Rémy¹  B. Rohith²  Florent Gasparin²  Sophie E. Cravatte³ 

[1] Mercator Ocean International, Toulouse, France;Mercator Ocean International, Toulouse, France;Université de Toulouse, LEGOS (IRD/UPS/CNES/CNRS), Toulouse, France;Université de Toulouse, LEGOS (IRD/UPS/CNES/CNRS), Nouméa, New Caledonia;

关键词: Argo floats;    tropical moored buoys;    ocean analysis systems;    observing system simulation experiment (OSSE);    impact studies;    ocean monitoring and forecasting systems;   

DOI  :  10.3389/fmars.2023.1021650

 received in 2022-08-17, accepted in 2023-01-16,  发布年份 2023

来源: Frontiers

【 摘 要 】

Ocean monitoring and forecasting systems combine information from ocean observations and numerical models through advanced data assimilation techniques. They are essential to monitor and report on past, present and future oceanic conditions. However, given the continuous development of oceanic models and data assimilation techniques in addition to the increased diversity of assimilated platforms, it becomes more and more difficult to establish how information from observations is used, and to determine the utility and relevance of a change of the global ocean observing system on ocean analyses. Here, a series of observing system simulation experiments (OSSE), which consist in simulating synthetic observations from a realistic simulation to be subsequently assimilated in an experimental analysis system, was performed. An original multiscale approach is then used to investigate (i) the impact of various observing system components by distinguishing between satellites and in situ (Argo floats and tropical moorings), and (ii) the impact of recommended changes in observing systems, in particular the impact of Argo floats doubling and enhancements of tropical moorings, on the fidelity of ocean analyses. This multiscale approach is key to better understand how observing system components, with their distinct sampling characteristics, help to constrain physical processes. The study demonstrates the ability of the analysis system to represent 40-80% of the temperature variance at mesoscale (20-30% for salinity), and more than 80% for larger scales. Satellite information, mostly through altimetric data, strongly constrains mesoscale variability, while the impact of in situ temperature and salinity profiles are essential to constrain large scale variability. It is also shown that future enhancements of Argo and tropical mooring arrays observations will likely be beneficial to ocean analyses at both intermediate and large scales, with a higher impact for salinity-related quantities. This work provides a better understanding on the respective role of major satellite and in situ observing system components in the integrated ocean observing system.

【 授权许可】

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Copyright © 2023 Gasparin, Lellouche, Cravatte, Ruggiero, Rohith, Le Traon and Rémy