Using Webb gliders to maintain a sustained ocean presence

Abstract

Buoyancy driven Slocum gliders were a vision of Douglas Webb, which Henry Stommel championed in a vision published in 1989. Slocum gliders have transitioned from a concept to a technology serving research and environmental stewardship. The long duration and low costs of gliders allow them to anchor spatial time series. Large distances, over 600 km, can be covered using a set of alkaline batteries. Lithium batteries can anchor missions that are thousands of kilometers in length. Since the initial tests, a wide range of physical and optical sensors have been integrated into the glider allowing measurements of temperature, salinity, depth averaged currents, surface currents, fluorescence, apparent/inherent optical properties active and passive acoustics. A command/control center, entitled Dockserver, has been developed that allows users to fly fleets of gliders simultaneously in multiple places around the world via the Internet. Since October 2003, Rutgers gliders have conducted 157 missions, traversed >55,000 kilometers, logged >2600 days at sea, and logged ~350,000 vertical profiles. The capabilities of the glider make them an indispensable tool for the growing global effort to build integrated ocean observatories. For example, gliders are now a central tool within the National Science Foundation Ocean Observatory Initiative (OOI) and the National Oceanic and Atmospheric Administration's Integrated Ocean Observing System (IOOS). Gliders provide a new magnet in which to attract young people into the ocean science and engineering. For example Rutgers undergraduates now anchor long duration flights of gliders world-wide beginning their freshmen year. This is critical to training the next generation.