Factors that cause seasonal variations in Beryllium-7 concentrations in surface air

Beryllium-7 Measurements in the Houston and Phoenix Urban Areas: An Estimation of Upper Atmospheric Ozone Contributions

“…The O 3 levels observed during this period were ϳ25 ppb, consistent with background concentrations anticipated for an air mass originating over the Gulf of Mexico. 14,20,26 Concentrations of other trace gas species, such as NO x , CO, and PAN, were also very low during this period. Note that the 7 Be levels were lower during this clean-air episode and higher on the preceding and following days.…”

“…The concentrations of 7 Be in surface air depend on cosmic ray intensity, highly variable stratosphere-troposphere exchange, downward transport of the aerosols in the troposphere resulting from the mixing of air through the depth of the troposphere, assumed to vary between 10 and 30 days depending on latitude, and wet and dry deposition of the carrier aerosols. [15][16][17][18][19][20][21] Consequently, the variability of 7 Be at a given spatial location is a sensitive indicator of intrusions of stratospheric air into the troposphere, over a base tropospheric turn over time. Thus, quantifying the 7 Be content in fine aerosols can give a measure of the transport of this fine aerosol material from the upper troposphere/lower stratosphere to the surface where it is sampled.…”

“…Thus, quantifying the 7 Be content in fine aerosols can give a measure of the transport of this fine aerosol material from the upper troposphere/lower stratosphere to the surface where it is sampled. Past work has suggested that this might be a useful way to determine stratospheric intrusions into the lower atmosphere and also to estimate the maximum extent to which stratospheric O 3 is affecting tropospheric sites during tropopause folding events, 9,[15][16][17][18][19][20][21]28,29 generally associated with intense storm events and frontal movements in the midlatitude northern hemisphere.…”

Evaluation of historical beryllium abundance in soils, airborne particulates and facilities at Lawrence Livermore National Laboratory

“…Several studies have shown that atmospheric Be-7 concentrations are seasonally variable, with a maximum in the summer season and a minimum in the fall/winter months (Azahra et al, 2004;Doering and Akber, 2008;Yamamoto et al, 2006). Feely et al (1989) investigated the atmospheric Be-7 concentration at a large number of sites across the world. Two of the locations reported by Feely et al (1989) are Richmond, CA from 1973to 1977and Tracy, CA from 1977-1981.…”

“…Feely et al (1989) investigated the atmospheric Be-7 concentration at a large number of sites across the world. Two of the locations reported by Feely et al (1989) are Richmond, CA from 1973to 1977and Tracy, CA from 1977-1981. Feely et al (1989 note that while these two locations are geographically close (i.e.…”