JAEA
  • help
  • PC | SP
  • JP | EN
          
Refine your search：     
Report No.
 - 
Clear All
Search Results: Records 1-2 displayed on this page of 2
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Analysis of factors contributing to the increase in $$^{7}$$Be activity concentrations in the atmosphere

Narazaki, Yukinori*; Sakoda, Akihiro; Akata, Naofumi*; Ito, Hisanori*; Momoshima, Noriyuki*

International Journal of Environmental Research and Public Health, 19(16), p.10128_1 - 10128_9, 2022/08

https://doi.org/10.3390/ijerph191610128
 Times Cited Count：1 Percentile：25.27(Environmental Sciences)

In March 2013, increased $$^{7}$$Be activity concentrations in the atmosphere were observed for successive days in Dazaifu, western Japan. The daily $$^{7}$$Be activity concentration averages ranged from 0.93 to 14 mBq/m$$^{3}$$, with a monthly average of 8.3 mBq/m$$^{3}$$. This average was the highest among the monthly averages observed between 1999 and 2015 and higher than the monthly average over this period (4.7 mBq/m$$^{3}$$) plus twice the standard deviation (1.7 $$times$$ 2 mBq/m$$^{3}$$ = 8.1 mBq/m$$^{3}$$). Also, this exceeded the monthly average (6.0 mBq/m$$^{3}$$) only for March 1999-2015, excluding 2013, where the cosmic-ray intensity, a component producing $$^{7}$$Be, decreased. Based on the backward trajectory analysis results, the inflow of air from the stratosphere and upper troposphere at high latitudes that frequently occurred in March 2013 was considered the reason for the $$^{7}$$Be activity concentration increase.

Journal Articles

Cosmogenic $$^{7}$$Be; Particle size distribution and chemical composition of $$^{7}$$Be-carrying aerosols in the atmosphere in Japan

Narazaki, Yukinori*; Sakoda, Akihiro; Takahashi, Shunta*; Momoshima, Noriyuki*

Journal of Environmental Radioactivity, 237, p.106690_1 - 106690_7, 2021/10

https://doi.org/10.1016/j.jenvrad.2021.106690
 Times Cited Count：3 Percentile：19.88(Environmental Sciences)

The particle size distributions of airborne aerosols with $$^{7}$$Be were measured using cascade impactors at Dazaifu, a city in western Japan, in 2018 to observe their seasonal variation. $$^{7}$$Be was found to be attached to aerosols with a particle size of less than 2.1 $$mu$$m; in general, particles sized 0.43-0.65 $$mu$$m had the highest $$^{7}$$Be activity concentrations. The activity median aerodynamic diameter (AMAD) of $$^{7}$$Be was in the range of 0.39-0.52 $$mu$$m, which is the size range of particles that can reach human alveoli, and had an annual mean of 0.43$$pm$$0.035 $$mu$$m. The activity concentrations of $$^{7}$$Be were significantly lower in summer, which affected its activity concentrations in the particle size distributions of $$^{7}$$Be. The particle size distribution of $$^{7}$$Be-carrying aerosols was also affected by that of the aerosol particles in the atmosphere. Finally, findings suggest that $$^{7}$$Be was mainly attached to sulfate aerosols (particularly ammonium sulfate aerosols).

2 (Records 1-2 displayed on this page)
  • 1