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An Open Source Seawater Carbonate Analyzer for the Citizen Scientist

Raised of $10,000 Goal
Funded on 8/08/23
Successfully Funded
  • $10,070
  • 100%
  • Funded
    on 8/08/23

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.

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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.


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The funds provided to this project will go directly to helping pay for the supplies and equipment needed to build the instruments and test their functionality.

The instrument will require several chemical reagents to work as they are based on the spectrophotometric method. It will also require standards and certified reference material as well as the required lab equipment to calibrate the instrument and verify its functionality.

Endorsed by

Jonathan is my PhD student in Chemical Oceanography in the MIT-WHOI Joint Program. He proposes to develop a hand-held low-cost pH/Alkalinity sensor with good measurement quality, specifically targeting citizen science and coastal monitoring of ocean acidification. This development represents an important step to make carbon sensing technologies more accessible to the public, and has the potential to significantly improve our capability to monitor and study ocean acidification in a cost-effective way.

Project Timeline

This is expected to be a one-year long project. First a proof-of-concept bench instrument will be built and tested. This version will be used to help develop the pH and total alkalinity methods. Then a phone app and field instrument will be built. In the spring, it will go through calibration and verification before undergoing some field testing the following summer.

Jun 24, 2023

Project Launched

Aug 01, 2023

Project Start

Sep 30, 2023

Proof of Concept Prototype System

Dec 31, 2023

Benchtop System

Mar 31, 2024

Full field instrument build

Meet the Team

Jonathan Pfeifer
Jonathan Pfeifer
Graduate Researcher


Massachusetts Institute of Technology, Woods Hole Oceanographic Institution
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Jonathan Pfeifer

I am a PhD candidate in the Chemical Oceanography program at the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution Joint Program. My research focus is on the advancement of precision sensors for measuring carbonate system parameters in seawater, including pH, dissolved inorganic carbon, partial pressure of CO2, and total alkalinity. My journey in carbonate system measurements began during my undergraduate studies at Flathead Valley Community College, where I studied coral calcification rates and developed new methods for measuring total alkalinity. I later transferred and received my undergraduate degree in electrical and computer engineering from Cornell University. I am dedicated to promoting open research practices and fostering citizen science initiatives.

Additional Information

I have a very strong passion for open research. The results of this project, particularly hardware designs and code, will be released under open source licenses for others to potentially learn from and be inspired by. And any publications that may come from this work will be published under open access so that they will be available to all.

Project Backers

  • 4Backers
  • 100%Funded
  • $10,070Total Donations
  • $2,517.50Average Donation
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