Evaluation of a New Carbon Dioxide System for Autonomous Surface Vehicles.

Current carbon measurement strategies leave spatiotemporal gaps that hinder the scientific understanding of the oceanic carbon biogeochemical cycle. Data products and models are subject to bias because they rely on data that inadequately capture mesoscale spatiotemporal (kilometers and days to weeks) changes. Highresolution measurement strategies need to be implemented to adequately evaluate the global ocean carbon cycle. To augment the spatial and temporal coverage of ocean-atmosphere carbon measurements, an Autonomous Surface Vehicle CO₂ (ASVCO₂) system was developed. From 2011 to 2018, ASVCO₂ systems were deployed on seven Wave Glider and Saildrone missions along the U.S. Pacific and Australia's Tasmanian coastlines and in the tropical Pacific Ocean to evaluate the viability of the sensors and their applicability to carbon cycle research. Here we illustrate that the ASVCO₂ systems are capable of long-term oceanic deployment and robust collection of air and seawater pCO₂ within ±2 µatm based on comparisons with established shipboard underway systems, with previously described Moored Autonomous pCO₂ (MAPCO₂) systems, and with companion ASVCO₂ systems deployed side by side. [ABSTRACT FROM AUTHOR]