TransCom continuous experiment: comparison of 222Rn transport at hourly time scales at three stations in Germany
Other literature type
Law, R. M.
Patra, P. K.
(issn: 1680-7324, eissn: 1680-7324)
Fourteen global atmospheric transport models were evaluated by comparing the
simulation of <sup>222</sup>Rn against measurements at three continental stations
in Germany: Heidelberg, Freiburg and Schauinsland. Hourly concentrations
simulated by the models using a common <sup>222</sup>Rn-flux without temporal
variations were investigated for 2002 and 2003. We found that the mean
simulated concentrations in Heidelberg are related to the diurnal amplitude
of boundary layer height in each model. Summer mean concentrations simulated
by individual models were negatively correlated with the seasonal mean of
diurnal amplitude of boundary layer height, while in winter the correlation
was positive. We also found that the correlations between simulated and
measured concentrations at Schauinsland were higher when the simulated
concentrations were interpolated to the station altitude in most models.
Temporal variations of the mismatch between simulated and measured
concentrations suggest that there are significant interannual variations in
the <sup>222</sup>Rn exhalation rate in this region. We found that the local
inversion layer during daytime in summer in Freiburg has a significant effect
on <sup>222</sup>Rn concentrations. We recommend Freiburg concentrations for
validation of models that resolve local stable layers and those at Heidelberg
for models without this capability.