Guidelines Towards an Integrated Ocean Observation System for Ecosystems and Biogeochemical Cycles

Abstract

The observation of biogeochemical cycles and ecosystems has traditionally been based on ship-based platforms. The obvious consequence is that the measured properties have been dramatically undersampled. Recent technological advances in miniature, low power biogeochemical sensors and autonomous platforms open remarkable perspectives for observing the "biological" ocean, notably at critical spatio-temporal scales which have been out of reach until present. The availability of this new observation technology thus makes it possible to envision the development of a globally integrated observation system that would serve both scientific as well as operational needs. This in situ system should be fully designed and implemented in tight synergy with two other essential elements of an ocean observation system, first satellite ocean color radiometry and second advanced numerical models of biogeochemical cycles and ecosystems. This paper gives guidelines and recommendations for the design of such system. The core biological and biogeochemical variables to be implemented are first reviewed, trying also to identify those for which the observational demand is high although the technology is not yet mature. A review of the five platforms now available (gliders, floats, animals with sensors, mooring at eulerian site and ships) allows their specific strengths with regards to biological and biogeochemical observations to be identified as well as to point out the community plans with respect to ongoing implementation. The critical issue of data management is addressed, acknowledging that the availability of

From the shape of the vertical profile of in vivo fluorescence to Chlorophyll-<i>a</i> concentration

“…Gregg and Conkright, 2002). Thanks to the miniaturization of bio-optical sensors, autonomous platforms (floats, gliders, animals) are now capable of acquiring vertical profiles of fluorescence over large distances (Sackmann et al, 2008;Niewiadomska et al, 2008, Claustre et al, 2010a or periods (up to 3 yr) (Boss et al, 2008). The extension and generalization of these "biogeochemical platforms" as part of a global network (Claustre et al, 2010a, b) similar to the Argo network Freeland et al, 2010) is expected for the near future.…”

“…Finally, the robustness of the relationship between shape and concentration may be a practical means to reconcile and harmonize datasets from various origins in a common currency, Chl-a concentration. As such it will have the potential to help producing large and coherent calibrated Chl-a profile datasets by merging past data acquired using ship-deployed fluorescence sensors to future profiles that will mostly be acquired through sensors carried by autonomous platforms (Claustre et al, 2010b).…”

Ocean-Atmosphere Interactions of Gases and Particles

“…The last OceanObs09 conference discussed the main priorities of the international community for Argo Freeland et al 2010;Claustre et al 2010). Based on the assessment that climate change research requires long-term, sustained, high quality and global observations, the leading priority and challenge for Argo must be to complete and sustain the global array.…”

“…Recent technological advances in biogeochemical sensors will permit the acquisition of new observations of the ocean interior (e.g. Claustre et al 2010;Adornato et al 2010). The main parameters that are considered for initial implementation are oxygen, nitrate, chlorophyll a and particulate carbon.…”

Stochastic estimation of biogeochemical parameters from Globcolour ocean colour satellite data in a North Atlantic 3D ocean coupled physical–biogeochemical model

“…However, such measurements are very sparse in space and time. Worldwide, very few sites in the open ocean are routinely monitored (e.g., on a monthly basis), whereas automatic sampling performed from floats or gliders is still a long-term prospective for biogeochemical quantities (Claustre et al, 2010). On the other hand, achieving a global coverage, repetitivity on a few days cycle and availability of the archive (more than a decade) are the main advantages of ocean colour satellite data.…”