⁷Be content and its seasonal variation in the ground air around Hangzhou area

7 Be content and its seasonal variation in the ground air around Hangzhou area 1 first-author Zhejiang Province Environmental Radiation Monitoring Center, Hangzhou 310012 Zhejiang Province Environmental Radiation Monitoring Center, Hangzhou 310012 Twice investigations around Hangzhou area show that 7 Be content average in the ground air is 5.9 mBq·m -3 . The content of 7 Be is the highest in autunm-winter period reaching about 7.7mBq·m -3 ; the next is in spring about 6.2mBq•m -3 ; then is in the early summer about 5.7 mBq·m -3 , close to the annual average level; and the lowest in a year is in summer-autumn period with a value about 3.8 mBq•m -3 . Exhibited is a decreasing trend from autumn-winter period to summer-autumn of the next year, which is negatively correlated with the variation of the seasonal rainfall in Hangzhou area. But this trend is different from that reported by UNSCEAR: it is the highest in spring and the lowest in the late autumn, which is based only on 7 Be falling down from the stratosphere. However, the present investigation shows that the seasonal rainfall is the main factor influencing the variation trend of 7 Be content in the air. 7 Be content Ground air Seasonal variation Seasonal rainfall References The Data Table of Commonly Used Nuclides Beijing : Atomic Energy Press , 1977 : 3 The Data Table of Commonly Used Nuclides Browne E , Firestone R B . Table of radioactive isotopes . New York : John Wiley and Sons, Inc ., 1986 Table of radioactive isotopes United Nations Scientific Committee on the Effects of Atomic Radiation . Sources and effects of atomic radiation . New York : United Nations , 1977 Sources and effects of atomic radiation Kolb W . Physikalisch-technische bunde-sanstalt report: Radionuclide concentrations in ground level air from 1971 to 1973 in Brunswick and Tromso . Brunschweig . 1974 Physikalisch-technische bunde-sanstalt report: Radionuclide concentrations in ground level air from 1971 to 1973 in Brunswick and Tromso Harley J H , U.S. energy research and development administration report: Environmental radon in noble gases . Washington DC , 1973 . 109 U.S. energy research and development administration report: Environmental radon in noble gases Beck H L . J Geophys Res . 1974 , 79 : 2215 J Geophys Res 1999-04-08 1999-11-01 2021-02-05 1999 Nuclear Science and Techniques 4 10