Seconds-Scale Response Sensor for In Situ Oceanic Carbon Dioxide Detection

Research on the transient variation processes of oceanic dissolved CO2 makes significant sense because of the complexity and dynamics of the marine environment. Yet, it is inherently challenging due to the limitation of the response performance of in situ sensors. Here, we report a novel system solution capable of providing high-performance detection with a seconds-scale response, sub-ppmv level precision, and 3000 m rated depth. Through the proposed strategy, we break the limitation of the membrane on the response performance of the sensor and improve it by 2 orders of magnitude to the tau(100) of 3.5 s (tau(90) = 2.7 s). By taking water temperature and CO2 concentration as the tracer, we succeed in portraying the water mixing process and reveal the microstructure of the concentration variation profile. By enabling in situ detection at an unprecedented response speed, this instrument can provide new insights and prospects into the research on the carbon cycle in deep-sea unstable regions, such as hydrothermal vents and cold seeps.

Automated summary

Research on the transient variation processes of oceanic dissolved CO2 is significant due to the complexity and dynamics of the marine environment. However, the response performance limitation of in situ sensors poses challenges. This study presents a novel system solution that overcomes this limitation, enabling high-performance detection with a seconds-scale response, sub-ppmv level precision, and 3000 m rated depth. By improving the response performance of the sensor, the water mixing process and concentration variation profile can be accurately portrayed, offering insights into carbon cycle research in deep-sea unstable regions.