Spatial mapping of dissolved inorganic carbon across Waquoit Bay

Project Title: Spatial mapping of dissolved inorganic carbon across Waquoit Bay

 Duration: (month/year to month/year): Mid-late Sept 2021

Funding Source(s): MIT Seagrant, NOAA OER, NSF

 Principal Investigator:  Mallory Ringham

Affiliation: MIT-WHOI

Email: mringham@whoi.edu

Project Description: Study of the marine CO₂ system is critical for understanding global carbon cycling and the impacts of changing ocean chemistry on marine ecosystems. A complete resolution of the marine CO₂ system requires simultaneous measurement of two out of four parameters: partial pressure of CO₂ (pCO₂), dissolved inorganic carbon (DIC), total alkalinity (TA), and pH. Currently, commercial sensors are only available for pCO₂ and pH, which often are difficult to deploy in turbid coastal environments, and traditional bottle sampling for seawater carbon chemistry prohibits measurements during poor weather or at night. We have been developing a new sensor, the CHAnnelized Optical System (CHANOS) II for high resolution autonomous DIC measurements. This sensor may be deployed from a stationary dock, mooring, or buoy for long term time-series analyses, or towed from a vehicle such as a ship, AUV, ROV, or CTD rosette. We will be towing this sensor, along with a suite of dissolved oxygen and commercial pH and pCO₂ sensors, across Waquoit Bay to test the sensor capabilities in creating a high-resolution surface map of DIC across high and low tidal cycles.