On the global estimates of geostrophic and Ekman surface currents

Lay Abstract A fundamental goal of physical oceanography is to provide a primary description of global ocean circulation. Historically, ocean surface currents were inferred from ship drift measurements, mainly in relation with navigational requirements. Ocean circulation was shown to play an important role in the last decades for studying the transport of heat, freshwater, momentum, and biogeochemical substances and is crucial to climate variability at both regional and global scales. It is particularly well known that, thanks to the Gulf Stream, a warm ocean current, Europe has a relatively mild climate considering its latitude. Measuring the ocean currents with great accuracy is instrumental for studying the movement of any material in the sea, from marine algae to turtles, and from plastic debris to oil spills. The advent of remote sensing has allowed surface currents to be estimated accurately using wind and sea‐level data observed from space. Our GEKCO (Geostrophic and Ekman Current Observatory) estimates of currents cover the global ocean from the Arctic Ocean (82°N) to the Antarctic continent (82°S) at a horizontal resolution of a quarter of a degree (~28 km). Estimates are available on a daily basis over the 2000–2008 period and have been fully validated with several independent data sets. Among the full range of cross‐disciplinary applications requiring the knowledge of oceanic currents, two examples focusing on plankton dynamics resulting from an iron fertilization experiment and the mechanical action of currents on the displacement of marine animals are discussed.