Document Type



The ocean carbon system plays a critical role in regulating carbon dioxide content in the atmosphere. With increased anthropogenic carbon input, it is even more important to understand the system through measurements, models, and predictions. Unfortunately, the spatiotemporal resolution of ocean carbon system measurements is limited by a lack of in situ instrumentation. The support of the Link Foundation Ocean Engineering and Instrumentation Fellowship has enabled me to make significant progress in developing an in situ carbon system instrument for the deep sea. The instrument will measure both total dissolved inorganic carbon (DIC) and the partial pressure of carbon dioxide (pCO2), allowing for full parameterization of the carbon system. The main challenge of developing such an instrument is achieving the required precision (± 1 µmol/kg for DIC,± 0.05 Pa for pCO2) [l], while maintaining a reasonable time response(< 5 minutes) and deep-sea capability (> 1000 m). These specifications allow for detection of changes in biogeochemical cycles and ocean acidification with sufficient spatial resolution during surveys [ 1-5]. This precision can be achieved by pairing tunable laser diode absorption spectroscopy (TLDAS), which has excellent field precision in atmospheric chemistry applications [6-8], with a deep-sea membrane interface [9,10]. The primary technical challenges are expanding TLDAS to cover an increased concentration range, quantifying the dynamic effects of the membrane interface, and designing a highly multidisciplinary integrated system for variable field conditions. With this instrument, scientists will have unprecedented access to high resolution, high precision carbon system measurements in the deep sea, opening many fuhll'e avenues of inquiry.


Anna PM Michel

Publication Date



Year received Link Fellowship: 2018-2019



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