Argo history

The concept of a neutrally buoyant float to measure subsurface ocean currents was developed simultaneously and independently in the mid-1950s by the USA (Stommel, 1955) and the UK (Swallow, 1955). The first floats were built and tested by Swallow and were used extensively to investigate features of the deep ocean. These initial floats have evolved over the years to become a P-ALACE (Argo) float. A summary of float development is provided below

• 1955 — Concept developed and first floats built
• Late 1960s - early 1970s — Transponder float developed; utilising the SOFAR channel for detection.
• 1980s — RAFOS floats developed utilising Argos satellite system.
• Late 1980s — ALACE floats developed returning to the surface at regular intervals.
• 1990s — P-ALACE floats developed carrying CTD sensors; transmitting profiles of temperature and salinity at regular intervals.

The first Argo deployment began in 2000 and by April 2002 had grown to almost 400 floats. The German Argo project started in 2004, but collaborating partners had already been involved in float deployments since the late 1990s.

The German contribution to Argo was initially funded by the Federal Ministry of Education and Research (BMBF) and involved the IFM-Geomar, the Alfred-Wegener Institute and the Bundesamt für Seeschifffahrt und Hydrographie. During a three-year pilot period a feasibility study was carried out  to test the network design before transition to a sustained operation. After an extension of the pilot study for another year the operational phase of Argo Germany started in 2008 and sustained funding is now provided by the Federal Ministry of Transport, Building and Urban Affairs.