About This Project

Measuring carbon dioxide parameters in seawater is crucial for understanding the impacts carbon dioxide has in our oceans, but current methods require bulky, expensive equipment and technical expertise. This project will develop a small, portable device for measuring pH and total alkalinity in seawater using the spectrophotometric method (Dickson et al. 2007; Yao & Byrn, 1998). It will empower citizen scientists around the globe to contribute valuable data on the ocean's carbonate system.

Ask the Scientists

What is the context of this research?

Increasing levels of atmospheric carbon dioxide are leading to more CO₂ dissolution in seawater, resulting in more bicarbonate and hydrogen ions (lower pH), but less carbonate ions in the water. This process is called ocean acidification and it has profound impacts on ocean chemistry, biology and ecosystems. (Kroeker et al., 2013, Doney et al., 2009)

Determining the current state of this "carbonate system" can be difficult. But by evaluating at least two of the four main carbonate parameters (pH, Total Alkalinity, CO₂ partial pressure, or overall Dissolved Inorganic Carbon) it becomes possible. Going through this process deepens our understanding of the carbonate system and reveals how ocean acidification alters the ocean's chemistry. (Dickson et al. 2007, Ch. 2, Doney et al., 2009)

What is the significance of this project?

The development of a cost-effective, user-friendly carbonate sensor could significantly transform carbonate chemistry research by eliminating many existing barriers to entry. The ability to measure two critical parameters of the seawater carbonate system without reliance on expensive, complex equipment means that researchers and individuals can more readily study the effects of ocean acidification in local waters.

As a result, we anticipate the democratization of ocean carbonate chemistry research, enabling participation from a wider range of people. This will foster new opportunities for understanding and insight into the impact ocean acidification has on our oceans, representing a significant contribution to this field of study.

What are the goals of the project?

Taking inspiration from previous work demonstrating the feasibility of LED intensity measurements for pH measurement, this project seeks to develop a novel prototype instrument, along with a companion mobile application.

The main goals are to design an instrument that improves light intensity measurements for high precision pH measurements, and to develop a method for total alkalinity measurements. Subsequent goals include testing it against certified reference materials, and performing field tests to verify measurement accuracy.

The accompanying mobile app controls the instrument and handles the calculations required to determine the critical parameters of the carbonate system in the water sample. This aligns with the functionality of the industry-standard CO2SYS program.