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222Rn as tracer for quantifying greenhouse gases fluxes: need of high quality and harmonized measurements of atmospheric concentrations and fluxes

Kolloquium der Abteilung 6

The impact of the atmospheric increase of the greenhouse gases (GHGs) on climate change is well known. Understanding the processes causing the emissions help in the implementation of emission reduction strategies. Thus GHGs emissions, due to natural as well as anthropogenic sources, must be estimated and reported by each country to the United Nations Framework Convention on Climate Change.

In order to estimate GHGs emissions, bottom-up (based on fuel consumption and anthropogenic activity data) and top-down methods (based on atmospheric observations and modelling) are both widely applied and the scientific community is focusing on reducing their related uncertainties.

Improvement of bottom-up and top-down methods has been carried out using independent techniques such as the Radon Tracer Method (RTM). In the RTM the atmospheric concentrations and the fluxes of the natural radioactive gas radon (²²²Rn) are used to retrieve GHGs fluxes.

The rule of radon gas as tracer for GHGs leads to the need of monitoring its atmospheric concentrations with high spatial density and to produce reliable radon flux inventories. Networks of atmospheric stations, such as ICOS and ClimaDat, are already including atmospheric ²²²Rn measurements. In addition, a harmonization of the experimental techniques applied for the measurements of atmospheric 222Rn concentrations and 222Rn fluxes is needed.

In this state of the research, the Radon Laboratory (LER) of the Institut de Tècniques Energètiques (INTE) of the Universitat Politècnica de Catalunya (UPC) is working, in collaboration with many national and international scientific groups, at : i) the improvement of techniques for the measurement of atmospheric 222Rn concentrations; ii) the building of robust and user friendly atmospheric radon monitors; iii) the enlargement of the atmospheric 222Rn measurements in Spain and their harmonization in Europe; iv) the improvement of continuous radon flux measurements; iv) the standardization of the Radon Tracer Method (RTM) for the retrieval of GHGs fluxes in rural and urban areas.

We will present here the state of the art of the research done in this field in order to make a step forward thanks to new shared projects.