Related Experiment Video
Updated: Feb 21, 2026
11:19
Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses
Published on: October 21, 2016
12.4K
COMPARISON OF VARIOUS APPROACHES TO DETERMINING CO2 FLUXES FROM THE SOIL BY 222Rn CALIBRATED METHOD.
K Holý1, M Mullerová1, V Palušová1
1Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská Dolina F-1, 841 04 Bratislava, Slovak Republic.
Radiation Protection Dosimetry
|October 6, 2017
Summary
Linear fits of soil CO2 and radon-222 (222Rn) profiles offer more reliable flux measurements than exponential fits. Direct soil CO2 flux measurements are typically higher than those estimated using 222Rn calibration methods.
Area of Science:
- Environmental Science
- Geochemistry
- Soil Science
Background:
- Accurate measurement of soil CO2 flux is crucial for understanding carbon cycling and climate change.
- Radon-222 (222Rn) calibration offers a method for estimating soil CO2 efflux.
- Different modeling approaches can influence the accuracy of 222Rn calibrated CO2 flux estimations.
Purpose of the Study:
- To evaluate various methods for determining soil CO2 fluxes using the 222Rn calibrated technique.
- To compare the uncertainties and reliability of exponential versus linear fitting models for CO2 and 222Rn depth profiles.
- To assess the agreement between 222Rn calibrated CO2 flux estimates and directly measured soil CO2 fluxes.
Main Methods:
- Testing multiple approaches for soil CO2 flux determination using 222Rn calibration.
- Analyzing CO2 and 222Rn concentration depth profiles using both exponential and linear fitting models.
- Comparing calculated CO2 fluxes with directly measured soil CO2 fluxes.
Main Results:
- Exponential fits of CO2 and 222Rn depth profiles introduced uncertainties up to 50% when profiles were not measured at sufficient depths.
- Linear fits of CO2 and 222Rn concentrations in the soil surface layer yielded lower uncertainties and flux values compared to exponential fits.
- Directly measured soil CO2 fluxes were generally tens of percent higher than those estimated via 222Rn calibrated methods.
- Estimated soil CO2 flux in sandy-clay, uncultivated soil was approximately 3.0 mmol m-2 h-1 in spring and 7.0 mmol m-2 h-1 in summer.
Conclusions:
- Linear fitting of soil surface CO2 and 222Rn concentrations provides a more robust and less uncertain method for estimating soil CO2 flux compared to exponential fitting of deeper profiles.
- Discrepancies exist between 222Rn calibrated flux estimates and direct measurements, suggesting potential limitations or calibration needs for the 222Rn method.
- Seasonal variations in soil CO2 flux were observed, highlighting the dynamic nature of carbon release from soils.
