Developing a Low-Cost Device for Estimating Air-Water ΔpCO₂ in Coastal Environments

Area of Science:

• Oceanography
• Environmental Science
• Sensor Technology

Background:

• The ocean is a major sink for anthropogenic carbon dioxide (CO2).
• Accurate measurement of CO2 flux at the air-sea interface is crucial but often limited by the high cost of traditional sensors (> $30,000).
• Existing monitoring systems face challenges in spatial coverage and resolution due to cost and logistical constraints.

Purpose of the Study:

• To develop and validate a low-cost system for measuring CO2 partial pressure (pCO2) in both water and air.
• To address the limitations of expensive sensors in ocean carbon budget studies.
• To enhance the capacity and accessibility of ocean CO2 monitoring.

Main Methods:

• Development of a low-cost (approx. $1400) system named Sensor for the Exchange of Atmospheric CO2 with Water (SEACOW).
• Integration of a low-cost K30 pCO2 sensor (approx. $100) and Internet of Things (IoT) capabilities.
• Calibration and validation of the SEACOW system against a LI-COR LI-850 analyzer.

Main Results:

• The SEACOW system demonstrates accurate atmospheric pCO2 measurements, within 2-3% of a calibrated LI-COR LI-850.
• The device successfully captured diel pCO2 cycling in seagrass environments.
• Technical specifications, including response times, were provided for the SEACOW and K30 sensor.

Conclusions:

• The SEACOW offers a cost-effective solution for ocean CO2 monitoring, significantly reducing the financial barrier.
• This technology can extend the spatial coverage and resolution of existing oceanographic monitoring networks.
• The SEACOW system facilitates improved understanding of air-sea CO2 exchange and ocean carbon budgets.