Investigating regional source and sink patterns of Alpine CO 2 and CH 4 concentrations based on a back trajectory receptor model

Background The main purpose of this paper is to contribute to the improvement in the present knowledge concerning regional carbon dioxide (CO2) and methane (CH4) exchange as an essential step towards reducing the uncertainties along with bottom-up estimations of their global budget by identifying the characteristic spatial and temporal scales of the regional greenhouse gas fluxes. To this end, we propose a stepwise statistical top-down methodology for examining the relationship between synoptic-scale atmospheric transport patterns and mole fractions of the climate gases to finally receive a characterisation of the sampling sites with regard to the key processes driving the CO2 or CH4 concentration levels.