On the Future of Argo: A Global, Full-Depth, Multi-Disciplinary Array

Abstract

The Argo Program has been implemented and sustained for almost two decades, as a global array of about 4000 profiling floats. Argo provides continuous observations of ocean temperature and salinity versus pressure, from the sea surface to 2000 dbar. The successful installation of the Argo array and its innovative data management system arose opportunistically from the combination of great scientific need and technological innovation. Through the data system, Argo provides fundamental physical observations with broad societally-valuable applications, built on the cost-efficient and robust technologies of autonomous profiling floats. Following recent advances in platform and sensor technologies, even greater opportunity exists now than 20 years ago to (i) improve Argo's global coverage and value beyond the original design, (ii) extend Argo to span the full ocean depth, (iii) add biogeochemical sensors for improved understanding of oceanic cycles of carbon, nutrients, and ecosystems, and (iv) consider experimental sensors that might be included in the future, for example to document the spatial and temporal patterns of ocean mixing. For Core Argo and each of these enhancements, the past, present, and future progression along a path from experimental deployments to regional pilot arrays to global implementation is described. The objective is to create a fully global, top-to-bottom, dynamically complete, and multidisciplinary Argo Program that will integrate seamlessly with satellite and with other in situ elements of the Global Ocean Observing System (Legler et al., 2015). The integrated system will deliver operational reanalysis and forecasting capability, and assessment of the state and variability of the climate system with respect to physical, biogeochemical, and ecosystems parameters. It will enable basic research of unprecedented breadth and magnitude, and a wealth of ocean-education and outreach opportunities.

Warm Events Induce Loss of Resilience in Organic Carbon Production in the Northeast Pacific Ocean

“…The development of warm anomalies in combination with a clear warming trend in the upper ocean (Lyman et al, 2010) may bring unprecedented reductions in carbon production and its subsequent export in the future, especially when extreme SLPa and SSTa predominate over two or more consecutive years. As we increase our capability for ocean observations using autonomous equipment, such as BGC floats (Roemmich et al, 2019), the chances of capturing other events should also increase. As we increase our capability for ocean observations using autonomous equipment, such as BGC floats (Roemmich et al, 2019), the chances of capturing other events should also increase.…”

“…Our study leaves some clues regarding the impact of warming oceans on net organic carbon production but also exposes the need for future studies so the mechanisms proposed here can prove replicable for future events and at different ocean basins. As we increase our capability for ocean observations using autonomous equipment, such as BGC floats (Roemmich et al, 2019), the chances of capturing other events should also increase.…”

Towards the integration of animal‐borne instruments into global ocean observing systems

“…The ocean observation network experienced a revolution with the advent of the Argo array of profiling floats since the beginning of this century (Abraham & Baringer, 2013;Riser et al, 2016;Roemmich et al, 2019). Argo is comprised of a global array of free-drifting profiling floats that measure temperature and salinity of the upper 2,000 m of the ocean (Riser et al, 2016).…”

“…Recent technological advances with two-way satellite communications (e.g. Iridium), and guidance on the use of, for example, floating buoys inside the EEZ of coastal states (IOC, 2008) has allowed the optimization of float endurances in marginal seas and coastal areas (Poulain et al, 2007;Roemmich et al, 2019). This has helped to clarify the details of water mass formation in the Mediterranean (Juza et al, 2019;Kokkini et al, 2019) and to improve predictions of the basin-scale circulation by assimilating profile data into numerical models of the circulation (Nilsson, Dobricic, Pinardi, Taillandier, & Poulain, 2011).…”

Sea Level Budgets Should Account for Ocean Bottom Deformation

“…Recently, it has been shown that the theoretical elastic OBD due to changes in mass load since 1993 contributes approximately 0.13 mm/year (or 3-4%) to global-mean sea level change (Frederikse et al, 2017). This contribution is comparable in magnitude to the deep steric contribution, which has been identified as one of the top priorities in sea level research (Roemmich et al, 2019;WCRP, 2018). Due to ongoing global warming, the rate of ocean mass change is expected to continue to increase, which will in-turn increase the elastic OBD in the near future.…”