Measurements of the effect of cyclic atmospheric pressure variation on the flux of ²²²RN from the soil

Abstract

A continuous recording accumulator method has been employed to study the effect of natural pressure cycles such as due to the passage of cyclonic weather systems on the time‐averaged flux of 222Rn from the soil. Results indicate a modest net enhancement of flux (∼10%) for pressure variation with standard deviations on the order of 0.2 in Hg.

Natural Radionuclides in the Atmosphere

“…Values of 1/b reported in the literature range from 100 to 218 cm (Clements and Wilkening, 1974;Dö rr and Mü nnich, 1990;Graustein and Turekian, 1990;Schery and Gaeddert, 1982). Values of 1/b reported in the literature range from 100 to 218 cm (Clements and Wilkening, 1974;Dö rr and Mü nnich, 1990;Graustein and Turekian, 1990;Schery and Gaeddert, 1982).…”

Validation of an off‐line three‐dimensional chemical transport model using observed radon profiles: 2. Model results

“…The rate at which radon emanates from the surface depends on many factors' the local concentration of 226Ra, the porosity and depth of soil, soil moisture and the type of vegetative cover [e.g., $chery et al., 1984]. Meteorological conditions affect the emission rate: ice cover significantly reduces the flux [Fisenne, 1985;D6rr, 1984;Genthon and Armengaud, 1995; Jacob and Prather, 1990;Feichter and Crutzen, 1990], precipitation may clog soil pores, and a modest decrease in surface air pressure of 1% can double the radon flux [Wilkening et al, 1975] (though this is a transient event that lasts only a few hours and is probably offset by a decrease in flux following the subsequent pressure increase; [Schery and Gaeddert, 1982]). Surface flux measurements of 222Rn range from •00.004 atoms cm -2 s -1 in New Zealand to •02.5 atoms cm -2 s -1 in Illinois [Turekian et al, 1977] and vary significantly with time and over short spatial scales [Wilkening et al, 1975].…”

Ground variation of radon 222 for location of hidden structural features. Example of the south of France (Alpes Maritimes)

“…For CLEMENT and WILKENING (1974), KLUSMAN and WEBSTER (1981), SCHERY and GAEDDERT (1982), a drop in the temperature causes the radon concentration to increase, while GABELMAN (1972in TIDJANI, 1984 observes the reverse and KOVACH (1945) minimizes its effect. PEARSON and JONES (1965and 1966in TIDJANI, 1984 note an abrupt decrease in the emanation during freezing periods.…”

“…Our bibliographical analysis shows that the results were sometimes contradictory, but we summarize as follows. It is generally recognized (KOVACH, 1945;CLEMENT and WILKENING, 1974;SCHERY and GAEDDERT, 1982) that atmospheric pressure variations produce an important effect. Strong concentrations correspond to low atmospheric pressures while high pressures cause the emanation to fall.…”