Submersible Autonomous Sensors for Oceanic Inorganic Carbon Characterization

University Of Montana, Missoula MT

Investigators

Abstract

P.I. De Grandpre (University of Montana) Proposal #: 0327763 Project Summary The PIs propose to develop autonomous sensors for total hydrogen ion concentration (pHT) and total alkalinity (TA). These measurements can be used together or in combination with other CO2 parameters to quantify oceanic total dissolved inorganic carbon and the partial pressure of CO2. The proposed research will develop autonomous sensors for pHT and TA that will be deployable on autonomous platforms such as moorings, Lagrangian drifters, and Volunteer Observing Ships. The PIs will attempt to achieve a level of precision and accuracy comparable to shipboard measurements. Furthermore, the PIs propose to commercialize the sensors and make them available to the oceanographic community as they have done with SAMI-CO2. Both TCO2 and pCO2 are critical components of ocean carbon cycle models and therefore, improved measurement systems are important for understanding the oceans' role in regulating atmospheric CO2 and climate warming. The proposed designs derive from the Submersible Autonomous Moored Sensor technology used for measurement of seawater pCO2 (SAMI-CO2). Like SAMI-CO2, the "SAMI-pH" and "SAMI-alk" sensors are based on spectrophotometric pH measurements. All three sensors utilize the same optical design, electronics boards, and plumbing components. The commercial availability of these components through Sunburst Sensors will greatly facilitate development of the sensors.