Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions - A case study for methane in Heidelberg
Correlations of nighttime atmospheric methane (CH4) and 222radon (222Rn) observations in Heidelberg, Germany, were evaluated with the radon tracer method (RTM) to estimate the trend of annual nocturnal CH4 emissions from 1996-2020 in the footprint of the station. After an initial 30ĝ€¯% decrease in emissions from 1996 to 2004, there was no further systematic trend but small inter-annual variations