Eighteen years of continuous observation of Radon and Thoron progenies atmospheric activity

IntroductionRadon (Rn-222), a radioactive gas with a half--life of 3.82 days, is emitted naturally (0.72-1.2 atoms·cm −2 ·s −1 ) from ice-free, unsaturated terrestrial surfaces [1,2]. The Rn-222 concentration in the near-surface air layer is undoubtedly strongly infl uenced by local conditions, which are connected with the environment of the gas emissions to the atmosphere (inter alia: geological formation, soil characteristics -radium content, permeability and porosity, temperature vertical profi le, soil heat fl ux, and humidity) and microclimatic conditions occurring in the near-ground air layer [3]. Research on Rn-222 in the context of meteorology dates back to the 1920s [4] and has developed intensively since the 1960s. In most publications, Rn-222 has been used to study the atmosphere as a natural tracer of the processes of transport and dispersion of gases [5][6][7][8][9][10][11]. Rn-222 has also been used as an indicator of vertical mixing processes resulting in the atmospheric stability regime [12][13][14][15][16][17]. The temporal variability of the Rn-222 concentration with reference to the meteorological variables (such as wind velocity and direction, atmospheric pressure, air tempera- Abstract. A unique, highly time-resolved, and synchronous three-year dataset of near-surface atmospheric radon-222 as well as soil heat fl ux and air temperature measurements at two sites (rural and urban) in Central Poland are investigated. The recognition of temporal variability of Rn-222 and selected meteorological variables in the urban and rural areas served to create two statistical models for estimation of this radionuclide concentration at 2 m a.g.l. The description of the relationships between the variables for individual months was established on the basis of an exponential function and an exponential function with time derivative of predictor to account for the hysteresis issue. The model with time derivative provided better results. The weakest fi tting of modelled data to empirical ones is observed for the winter months. During subsequent seasons, air temperature as well as QG-driven (soil heat fl ux) models exhibited very high agreement with the empirical data (MBE, RMSE, MAE, and 'index of agreement' by Willmott were used to evaluate the models). A restriction in the use of QG for Rn-222 concentration was observed only in winter in the case of snow cover occurrence, which reduces the daily QG variability.

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“…ture, precipitation, and snow cover occurrence) was presented in the studies by [17][18][19][20][21][22][23][24].…”

mentioning

confidence: 99%

Soil heat flux and air temperature as factors of radon (Rn-222) concentration in the near-ground air layer

Podstawczyńska

Pawlak

2016

Nukleonika

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“…While Postend€ orfer et al (1994) concluded that, in a building with relatively stable air temperature, wind-speed was the principal factor determining indoor radon concentrations, an extended study (3000 daily samples in three near-continuous groups) (Kobayashi, 2000) failed to identify such a correlation, although the power-spectrum of the radon progeny ratio was shown to be similar to that of wind-speed. Miles (2001) demonstrated good correlation between mean radon concentration and monthly temperature, but only while outdoor temperature is lower than that indoors, as required by the indoor under-pressure model (Eaton and Scott, 1984). Climent et al (1999) showed radon concentration correlating inversely with air temperature and soil temperature at 300 mm soil depth, and directly with humidity, rainfall and wind direction, in each case with minimal latency.…”

Section: Radon and Climatementioning

confidence: 95%

“…Investigations into the effect of climate on radon concentration in three undisturbed domestic basement rooms in Northamptonshire failed to demonstrate rigorous causality, although weak correlations with precipitation and mean daily temperature were identified (Groves-Kirkby et al, 2006). Florea and Duliu (2012), reporting eighteen years of continuous observation of atmospheric radon, identified negative correlation between radon concentration and precipitation, temperature and sky cloudiness. Wavelet and power spectra confirmed the predominance of one year periodicity, with additional components with periodicity of 1.2, 1.5, 2.8 and 7.2 years.…”

Section: Radon and Climatementioning

confidence: 99%

“…In climates where homes are heated for at least part of the year, indoor air is generally warmer and less dense than outdoor air. The consequent pressure differential, the prime driving force for entry of soil-gas and its entrained radon, is modulated by the Bernoulli effect influence of wind passing around and over the building, with wind-speed contributing significantly in determining radon ingress (Eaton and Scott, 1984).…”

Section: Seasonal Variability Of Domestic Radonmentioning

confidence: 99%

“…This relationship applies only while average outdoor temperatures are lower than those indoors (and T 26.2 C), the necessary condition for the classical driving mechanisms (Åkerblom et al, 1984;Eaton and Scott, 1984). Developing this approach, Miles (2009a, 2009b) presented a more general formula relating the mean annual radon concentration, R, in a dwelling to the occupancy-weighted mean radon concentration, C, observed in that dwelling during a relatively short measurement period, and the mean external temperature, T, during the same period:…”

Section: Seasonal Variability and Ambient Temperaturementioning

confidence: 99%

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A critical analysis of climatic influences on indoor radon concentrations: Implications for seasonal correction

Groves-Kirkby

Crockett

Denman

et al. 2015

Journal of Environmental Radioactivity

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Although statistically-derived national Seasonal Correction Factors (SCFs) are conventionally used to convert sub-year radon concentration measurements to an annual mean, it has recently been suggested that external temperature could be used to derive local SCFs for short-term domestic measurements. To validate this approach, hitherto unanalysed radon and temperature data from an environmentally-stable location were analysed. Radon concentration and internal temperature were measured over periods totalling 1025 days during an overall period of 1762 days, the greatest continuous sampling period being 334 days, with corresponding meteorological data collected at a weather station 10 km distant. Mean daily, monthly and annual radon concentrations and internal temperatures were calculated. SCFs derived using monthly mean radon concentration, external temperature and internal-external temperature-difference were cross-correlated with each other and with published UK domestic SCF sets. Relatively good correlation exists between SCFs derived from radon concentration and internal-external temperature difference but correlation with external temperature, was markedly poorer. SCFs derived from external temperature correlate very well with published SCF tabulations, confirming that the complexity of deriving SCFs from temperature data may be outweighed by the convenience of using either of the existing domestic SCF tabulations. Mean monthly radon data fitted to a 12-month sinusoid showed reasonable correlation with many of the annual climatic parameter profiles, exceptions being atmospheric pressure, rainfall and internal temperature. Introducing an additional 6-month sinusoid enhanced correlation with these three parameters, the other correlations remaining essentially unchanged. Radon latency of the order of months in moisture-related parameters suggests that the principal driver for radon is total atmospheric moisture content rather than relative humidity.

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Differences of near-ground atmospheric Rn-222 concentration between urban and rural area with reference to microclimate diversity

Podstawczyńska

2016

Atmospheric Environment

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Eighteen years of continuous observation of Radon and Thoron progenies atmospheric activity

Cited by 18 publications

References 13 publications

Soil heat flux and air temperature as factors of radon (Rn-222) concentration in the near-ground air layer

Soil heat flux and air temperature as factors of radon (Rn-222) concentration in the near-ground air layer

A critical analysis of climatic influences on indoor radon concentrations: Implications for seasonal correction

Differences of near-ground atmospheric Rn-222 concentration between urban and rural area with reference to microclimate diversity

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