Study of the factors influence on variation of Be-7 concentration in surface air at Osaka, Japan. (August 2019)

• Record Type: Journal Article
• Authors: Noithong, P; Rittirong, A; Hazama, R
• Is Part Of: Journal of physics. Volume 1285(2019)
• Publication Date: 2019-08
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/1285/1/012016
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: The concentration of 7 Be in surface air and rainwater at Daito, Osaka (34.71 N, 135.64 E) has been measured during the period from January 8 to October 29, 2018 and April 1 to October 31, 2018, respectively. The weekly concentration of 7 Be in surface air in the range of 8.92 ± 0.08 to 1.03 ± 0.02 mBq/m 3 showing seasonal trend with maxima in spring and autumn and minima in summer, which can be ascribed to the transport of air masses from low latitudes carrying low 7 Be concentration into the middle latitude region. The factors influences on the concentration of 7 Be were examined. It was shown that the positive and negative correlation was found in PM2.5 (cc = 0.62) and relative humidity (cc = –0.57), respectively. The weak positive correlation was found in cosmic ray intensity (cc = 0.23), the weak negative correlation was found in precipitation (cc = –0.14) and sunspot number (cc = –0.05). The deposition rate was analyzed by using the rainwater samples. It shown negative correlation between deposition rate and precipitation (cc = –0.53). High volumes of precipitation can reduce the 7 Be concentration of air by wash-out.