Short Description
The MIRO Gas Analyzer is a laser-based trace gas measurement system designed for high-frequency detection of carbonyl sulfide (COS) in the atmosphere. The instrument operates at sampling frequencies up to 10 Hz, enabling its use in eddy covariance applications for ecosystem-scale flux measurements.
Carbonyl sulfide is increasingly used as a proxy for photosynthetic activity because plant uptake of COS is closely linked to stomatal conductance and carbon assimilation. High-frequency COS measurements allow the direct quantification of COS exchange between ecosystems and the atmosphere, providing complementary information to CO₂ flux measurements.
The analyzer is deployed in micrometeorological setups, particularly eddy covariance towers, where it is coupled with sonic anemometers and other gas analyzers. This configuration enables the calculation of COS fluxes at ecosystem scale and supports improved estimates of gross primary productivity (GPP). By integrating COS flux measurements with conventional CO₂ flux data, uncertainties in partitioning net ecosystem exchange into photosynthesis and respiration can be reduced.
The system is suitable for continuous field operation and can be applied across a wide range of ecosystems, including forests, grasslands, and agricultural systems.
Contact Person
Georg Wohlfahrt
Research Services
Flux measurement of CO2, H2O and COS.
Methods & Expertise for Research Infrastructure
The MIRO gas analyzer is used for high-frequency (10 Hz) measurements of atmospheric carbonyl sulfide (COS) to quantify ecosystem–atmosphere exchange processes. The instrument is integrated into eddy covariance systems together with sonic anemometers and CO₂/H₂O analyzers, enabling direct flux measurements at ecosystem scale.
Methodological expertise includes flux calculation and quality control, spectral corrections, coordinate rotation, frequency response corrections, and footprint analysis. COS fluxes are interpreted in combination with CO₂ and meteorological measurements to investigate biosphere–atmosphere exchange processes and environmental controls on gas exchange.
A key application is the use of COS as an independent tracer of stomatal uptake and photosynthetic activity. By combining COS fluxes with conventional CO₂ flux partitioning approaches, improved estimates of gross primary productivity (GPP) can be derived. The infrastructure supports studies on stomatal regulation, drought responses, light and vapor pressure deficit effects, and seasonal ecosystem dynamics.
The facility is operated by researchers with expertise in micrometeorology and plant ecophysiology. Experience includes field deployments across forest and managed ecosystems, integration with chamber measurements and leaf-level observations, and the development of data processing workflows and modeling approaches for COS-based ecosystem productivity assessment.
Allocation to research infrastructure
Forest-atmosphere-interaction-research (FAIR) site (Waldforschungsstation Mieming)
Understanding the mechanism of plant carbonyl sulfide uptake, Sophie Baartman, 2026-2029, FWF, https://www.fwf.ac.at/forschungsradar/10.55776/ESP3194225