Ground based radon-222 observations and their application to atmospheric studies

Zahorowski, W.; Chambers, Scott D.; Henderson‐Sellers, A.

doi:10.1016/j.jenvrad.2004.03.033

Cited by 133 publications

(92 citation statements)

References 74 publications

(123 reference statements)

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“…It has been used as a tracer to study transport processes in the atmosphere (e.g. Liu et al, 1984;Chevillard et al, 2002) and to evaluate or compare the transport component in atmospheric trans-port models (Dentener et al, 1999;Gupta et al, 2004;Zahorowski et al, 2004). Another highly useful application of 222 Rn is the direct inversion method commonly referred to as the 222 Rn tracer method (Levin, 1987;Schmidt et al, 1996;van der Laan et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Inferring 222Rn soil fluxes from ambient 222Rn activity and eddy covariance measurements of CO2

et al. 2016

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Abstract. We present a new methodology, which we call Single Pair of Observations Technique with Eddy Covariance (SPOT-EC), to estimate regional-scale surface fluxes of 222 Rn from tower-based observations of 222 Rn activity concentration, CO 2 mole fractions and direct CO 2 flux measurements from eddy covariance. For specific events, the regional ( 222 Rn) surface flux is calculated from short-term changes in ambient ( 222 Rn) activity concentration scaled by the ratio of the mean CO 2 surface flux for the specific event to the change in its observed mole fraction. The resulting 222 Rn surface emissions are integrated in time (between the moment of observation and the last prior background levels) and space (i.e. over the footprint of the observations). The measurement uncertainty obtained is about ±15 % for diurnal events and about ±10 % for longerterm (e.g. seasonal or annual) means. The method does not provide continuous observations, but reliable daily averages can be obtained. We applied our method to in situ observations from two sites in the Netherlands: Cabauw station (CBW) and Lutjewad station (LUT). For LUT, which is an intensive agricultural site, we estimated a mean 222 Rn surface flux of (0.29 ± 0.02) atoms cm −2 s −1 with values > 0.5 atoms cm −2 s −1 to the south and southeast. For CBW we estimated a mean 222 Rn surface flux of (0.63 ± 0.04) atoms cm −2 s −1 . The highest values were observed to the south-west, where the soil type is mainly river clay. For both stations good agreement was found between our results and those from measurements with soil chambers and two recently published 222 Rn soil flux maps for Europe. At both sites, large spatial and temporal variability of 222 Rn surface fluxes were observed which would be impractical to measure with a soil chamber. SPOT-EC, therefore, offers an important new tool for estimating regional-scale 222 Rn surface fluxes. Practical applications furthermore include calibration of process-based 222 Rn soil flux models, validation of atmospheric transport models and performing regional-scale inversions, e.g. of greenhouse gases via the SPOT 222 Rntracer method.

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Section: Introductionmentioning

confidence: 99%

Inferring 222Rn soil fluxes from ambient 222Rn activity and eddy covariance measurements of CO2

et al. 2016

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“…이들 중 일부는 폐에서 제거되거나 기침으로 배출되지 만 대부분은 붕괴하면서 α-ray를 방출하여 장기적으로 폐암을 유발하는 것으로 보고되고 있다 (Choi et al, 2009;Miles, 1988 (Zahorowski et al, 2004).…”

Section: 서 론unclassified

Background Level and Time Series Variation of Atmospheric Radon Concentrations at Gosan Site in Jeju Island

Song¹,

Bu²,

Kim³

et al. 2017

Journal of Korean Society for Atmospheric Environment

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“…This approach, designed for the case of diurnal pollution fluxes in a small city, can be considered to be a generalisation of both the well-known 'radon calibration' technique, used to obtain regional flux estimates [e.g. Zahorowski et al, 2004; eq. (7)], and the 'nocturnal storage-ratio' method, used to estimate nocturnal fluxes at the field scale using a similarly distributed reference species (e.g.…”

Section: Radon-based Box Model With Advectionmentioning

confidence: 99%

Radon as a tracer of atmospheric influences on traffic-related air pollution in a small inland city

Williams¹,

Chambers²,

Conen³

et al. 2016

Tellus B: Chemical and Physical Meteorology

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A B S T R A C T One year of radon, benzene and carbon monoxide (CO) concentrations were analysed to characterise the combined influences of variations in traffic density and meteorological conditions on urban air quality in Bern, Switzerland. A recently developed radon-based stability categorisation technique was adapted to account for seasonal changes in day length and reduction in the local radon flux due to snow/ice cover and high soil moisture. Diurnal pollutant cycles were shown to result from an interplay between variations in surface emissions (traffic density), the depth of the nocturnal atmospheric mixing layer (dilution) and local horizontal advection of cleaner air from outside the central urban/industrial area of this small compact inland city. Substantial seasonal differences in the timing and duration of peak pollutant concentrations in the diurnal cycle were attributable to changes in day length and the switching to/from daylight-savings time in relation to traffic patterns. In summer, average peak benzene concentrations (0.62 ppb) occurred in the morning and remained above 0.5 ppb for 2 hours, whereas in winter average peak concentrations (0.85 ppb) occurred in the evening and remained above 0.5 ppb for 9 hours. Under stable conditions in winter, average peak benzene concentrations (1.1 ppb) were 120% higher than for well-mixed conditions (0.5 ppb). By comparison, summertime peak benzene concentrations increased by 53% from well-mixed (0.45 ppb) to stable nocturnal conditions (0.7 ppb). An idealised box model incorporating a simple advection term was used to derive a nocturnal mixing length scale based on radon, and then inverted to simulate diurnal benzene and CO emission variations at the city centre. This method effectively removes the influences of local horizontal advection and stability-related vertical dilution from the emissions signal, enabling a direct comparison with hourly traffic density. With the advection term calibrated appropriately, excellent results were obtained, with high regression coefficients in spring and summer for both benzene (r 2 Â0.90Á0.96) and CO (r 2 Â0.88Á0.98) in the two highest stability categories. Weaker regressions in winter likely indicate additional contributions from combustion sources unrelated to vehicular emissions. Average vehicular emissions during daylight hours were estimated to be around 0.503 (542) kg km (2 h (1 for benzene (CO) in the Bern city centre.

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Ground based radon-222 observations and their application to atmospheric studies

Cited by 133 publications

References 74 publications

Inferring <sup>222</sup>Rn soil fluxes from ambient <sup>222</sup>Rn activity and eddy covariance measurements of CO<sub>2</sub>

Inferring <sup>222</sup>Rn soil fluxes from ambient <sup>222</sup>Rn activity and eddy covariance measurements of CO<sub>2</sub>

Background Level and Time Series Variation of Atmospheric Radon Concentrations at Gosan Site in Jeju Island

Radon as a tracer of atmospheric influences on traffic-related air pollution in a small inland city

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Ground based radon-222 observations and their application to atmospheric studies

Cited by 133 publications

References 74 publications

Inferring &lt;sup&gt;222&lt;/sup&gt;Rn soil fluxes from ambient &lt;sup&gt;222&lt;/sup&gt;Rn activity and eddy covariance measurements of CO&lt;sub&gt;2&lt;/sub&gt;

Inferring &lt;sup&gt;222&lt;/sup&gt;Rn soil fluxes from ambient &lt;sup&gt;222&lt;/sup&gt;Rn activity and eddy covariance measurements of CO&lt;sub&gt;2&lt;/sub&gt;

Background Level and Time Series Variation of Atmospheric Radon Concentrations at Gosan Site in Jeju Island

Radon as a tracer of atmospheric influences on traffic-related air pollution in a small inland city

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Inferring <sup>222</sup>Rn soil fluxes from ambient <sup>222</sup>Rn activity and eddy covariance measurements of CO<sub>2</sub>

Inferring <sup>222</sup>Rn soil fluxes from ambient <sup>222</sup>Rn activity and eddy covariance measurements of CO<sub>2</sub>