American researchers used a vorticity covariance system (portable vorticity covariance tower installed on a high pole) to continuously measure the net ecosystem fluxes of COS, CO ₂, and H ₂ O. They used an automatic soil flux chamber combined with a quantum cascade laser spectrometer to continuously monitor soil COS and CO ₂ fluxes. The study was conducted in a small wheat field in the southern Great Plains of Oklahoma, USA from April 4 to June 6, 2012, covering the wheat growing season, aging period, and post harvest stage.

The research results indicate that: (1) Vegetation absorption is the main sink of ecosystem COS, and during the peak growth season, vegetation absorption dominates, with soil flux accounting for only 1-6% of net ecosystem COS absorption; (2) Soil is the source and sink of COS, regulated by temperature. Soil becomes a COS sink at low temperatures (<15 ° C) and a source at high temperatures. Soil moisture content affects the response of COS flux to temperature, with a stronger response at high moisture content; (3) There is consistency between leaf relative absorption rate (LRU) and ecosystem relative absorption rate (ERU), supporting COS as an independent tracer for ecosystem to regional scale photosynthesis. Nighttime vegetation absorption and soil emissions need to be corrected in the model.

The core equipment used in the above research is a quantum cascade laser spectrometer (model: CW-QC-TILDAS), which continuously and high-frequency measures the concentrations of COS, CO ₂, and H ₂ O. The Aerodyne carbonyl sulfide monitoring system, represented by Auso, directly measures various trace gases such as COS, CO2, H2O, and CO, providing in-depth research on the mechanisms of ecosystem response to environmental changes.

The technical advantages of this product are as follows:

Tracer for studying total photosynthesis: COS is only related to the photosynthetic absorption of CO2 and is not related to respiration, so it can be used as a tracer for studying total photosynthesis. It can be used to calibrate and validate the photosynthesis modules in terrestrial ecosystem models and Earth system models, making model predictions more reliable.

Coupling measurement of COS and CO2: Coupling measurement of COS and CO ₂ is a cutting-edge and powerful paradigm in current carbon cycle research, which can accurately quantify the impact of soil and plant self emissions (such as aging tissues) on flux, clarify the applicable boundaries and sources of uncertainty of COS tracing method.

High precision and high-frequency measurement: COS measurement accuracy is accurate, with a 1-second precision of 5ppt, reliably separating the real COS flux signal from instrument noise to ensure data authenticity. The measurement frequency is 10Hz, meeting the requirements of vorticity covariance technology, which can greatly reduce the uncertainty of the model in simulating photosynthesis and carbon cycle.