Developing and testing new sensors for characterising ocean carbon dioxide uptake

About the Project

Supervisory Team: Dr Adrian Nightingale, Dr Allison Schaap, and Prof Rachael James

Oceans are critical to the changing climate, having absorbed a third of all anthropogenic carbon dioxide; hence monitoring ocean uptake is essential for understanding, modelling, and mitigating climate change. This project looks to develop and test novel sensors to do so, based on droplet microfluidic technology.

At least two measurements are required to accurately quantify dissolved carbon in seawater, one of which can be alkalinity, the focus of this project. Alkalinity represents the water’s ability to buffer against the acidification caused by carbon input. Existing alkalinity sensing technology is currently highly immature, but if alkalinity sensors could be developed to the stage where they are routinely widely used, we would be able to significantly increase the quantity and spatiotemporal coverage of measurements and hence increase understanding of CO2 uptake processes.

The supervisory team has a strong history of developing ocean sensors, including alkalinity sensors that can accurately measure alkalinity at depth (several km), over long periods (months). While these sensors are highly effective in most scenarios, they are poorly-suited to scenarios where alkalinity can change rapidly and by large amounts (e.g. estuaries, coral reefs, sea-grass meadows, and marine carbon dioxide removal sites) due to long measurement times and narrow measurement ranges. To address these challenges, we have recently used droplet microfluidic technology to create a new alkalinity sensor: Wide Range Alkalinity Spectrophotometric Sensor (WRASSe).

WRASSe has been demonstrated in the lab but is yet to be used in-the-field. The goal of this project is to explore how this novel technology can be employed to deliver insights on marine environments with wide ranging alkalinities, with results from real-world testing (e.g. monitoring alkalinity fluctuations in estuaries due to mixing of highly alkaline rivers with seawater) leading to iterative redesign and development of the sensor.

In addition to the University of Southampton supervisors, this project also includes Dr Allison Schaap as an external supervisor.

Entry requirements

You must have a UK 2:1 honours degree, or its international equivalent, in one of the following:

• oceanography
• environmental science
• chemistry
• other engineering discipline

You must be curious and ready to engage with the other academic disciplines. For instance, engineers will need to learn basic marine carbonate chemistry, while environmental scientists will need to learn computer aided design (CAD) and microfluidic fabrication techniques.

Fees and funding

We offer a range of funding opportunities for both UK and international students. Horizon Europe fee waivers automatically cover the difference between overseas and UK fees for qualifying students.

Competition-based Presidential Bursaries from the University cover the difference between overseas and UK fees for top-ranked applicants.

Competition-based studentships offered by our schools typically cover UK-level tuition fees and a stipend for living costs for top-ranked applicants.

Funding will be awarded on a rolling basis, so apply early for the best opportunity to be considered.

For more information, please visit our postgraduate research funding pages.

How to apply

Apply now

You need to:

• choose programme type (Research), 2026/27, Faculty of Engineering and Physical Sciences
• select Full time or Part time
• search for programme PhD Engineering & the Environment (7175)
• add name of the supervisor in section 2 of the application

Applications should include:

• your CV (resumé)
• 2 academic references
• degree transcripts and certificates to date
• English language qualification (if applicable)