Observing Biogeochemical Cycles at Global Scales with Profiling Floats and Gliders: Prospects for a Global Array

Chemical and biological sensor technologies have advanced rapidlyin the past five years. Sensors that require low power and operate for multiple yearsare now available for oxygen, nitrate, and a variety of bio-optical properties thatserve as proxies for important components of the carbon cycle (e.g., particulateorganic carbon). These sensors have all been deployed successfully for long periods,in some cases more than three years, on platforms such as profiling floats or gliders.Technologies for pH, pCO2, and particulate inorganic carbon are maturing rapidly aswell. These sensors could serve as the enabling technology for a global biogeochemicalobserving system that might operate on a scale comparable to the current Argo array.Here, we review the scientific motivation and the prospects for a global observingsystem for ocean biogeochemistry.