TransCom continuous experiment: comparison of <sup>222</sup>Rn transport at hourly time scales at three stations in Germany

Abstract

Abstract. Fourteen global atmospheric transport models were evaluated by comparing the simulation of 222 Rn against measurements at three continental stations in Germany: Heidelberg, Freiburg and Schauinsland. Hourly concentrations simulated by the models using a common 222 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 222 Rn exhalation rate in this region. We found that the local inversion layer during daytime in summer in Freiburg has a significant effect on 222 Rn concentrations. We recommend Freiburg concentrations for validation of models that resolve local stable layers and those at Heidelberg for models without this capability.

Air‐sea gas transfer rate for the Southern Ocean inferred from 222Rn concentrations in maritime air and a global atmospheric transport model

“…This boundary layer diffusion is a determinant in this study and will be described later. The model has previously been applied to 222 Rn and other species [Wada et al, 2007;Law et al, 2008;Patra et al, 2008;Sawa et al, 2008;Taguchi et al, 2011].…”

Impact of transport model errors on the global and regional methane emissions estimated by inverse modelling

“…Chronologically, the TransCom community characterized the atmospheric transport of CO 2 (Law et al, 1996;Geels et al, 2007), SF 6 (Denning et al, 1999), 222 Rn (Taguchi et al, 2011), and, more recently, CH 4 . One major outcome of the TransCom experiment, described in Patra et al (2011), was that deficiencies in the ability of CTMs to accurately reproduce atmospheric methane concentrations hindering efforts to improve our knowledge on sources and sinks of methane.…”

Evaluation of anthropogenic emissions of carbon monoxide in East Asia derived from the observations of atmospheric radon-222 over the western North Pacific

“…The emanation rate of 222 Rn was given a value of 1.0 atoms cm −2 s −1 for all the land areas between 60 • S and 60 • N, and 0.5 atoms cm −2 s −1 for the land areas between 60 • N and 70 • N, excluding Greenland, with no temporal variation (Jacob et al, 1997;Taguchi et al, 2002bTaguchi et al, , 2011. The emanation rate of 222 Rn from the ocean was set to 0 atoms cm −2 s −1 , since our study focused on the short term variations in atmospheric 222 Rn.…”