Lay summary
Regional European emissions of non-CO2 greenhouse gases (methane, nitrous oxide and halocarbons) will be estimated by using continuous ground-based measurements of these gases in combination with measurements of Radon (222Rn) and meteorological transport models. The proposed project will advance methods to obtain reliable and independent emission numbers which can be used to check emissions to be reported by the signatory countries within the Kyoto Protocol.
Empa has already previously developed methods for the allocation of European source regions of non-CO2 greenhouse gases. They were based on measurements of these gases at Jungfraujoch, concurrent measurements of carbon monoxide (CO) used for scaling of the source fluxes and Lagrangian transport models. However, the distribution of the CO emissions is highly variable and the quality of the Lagrangian transport model could not yet be evaluated satisfactorily. Therefore, a new approach will be developed within this proposal, which uses measurements of 222Rn and the new European 222Rn flux maps, recently developed by the University of Basel (Institute of Environmental Geosciences). 222Rn is well suited for this purpose as it can be measured accurately, has a precisely known half-lifetime (3.8 days) and has a well characterized source distribution. Furthermore, as both its global background and half-lifetime are small, enhanced concentrations measured at Jungfraujoch are caused by European emissions solely.
The new method will be first applied to measurements at Jungfraujoch to assess countryspecific emissions in Western Europe. For a more in-depth analysis of Northern Italian sources the same approach will be applied to Monte Cimone (Italy). Because eastern European emissions are not well covered by existing continuous measurements, a campaign at a Hungarian site (Hegyhatsal) will be used to estimate emissions from this part of Europe.
The main objectives of this project are:
1) Use measurements of 222Rn in combination with other trace gases to assess the ability of Lagrangian models to correctly describe the transport from potential source regions to the selected sites.
2) Estimate regional European emissions of non-CO2 greenhouse gases by combining their continuous measurements with measurements and emission maps of 222Rn and with quality-checked information on transport provided by the Lagrangian models.
3) Use measurements of CO and 222Rn at Jungfraujoch to discern between European pollution events and intercontinental influence.
This project is a joint initiative of the Laboratory for Air Pollution/Environmental Technology (Empa) with the Institute of Environmental Geosciences (University of Basel).