大气中γ辐射空气吸收剂量率的波动机制

基于广西防城港市、福建福清市和宁德市的3个滨海核电厂周边γ辐射空气吸收剂量率长时间高频率的连续观测数据，从不同时间尺度进行系统解析.研究发现，在年际尺度上，2014~2020年间宁德嵛山岛站位γ辐射空气吸收剂量率呈现先上升后下降的趋势，与太阳活动的先减弱后增强存在一定的反相位关联；在季节尺度上，2019年度3个站位的观测均呈现东亚季风主导下的海洋气团与大陆气团控制γ辐射空气吸收剂量率夏低冬高的季节特征；在昼夜尺度上，福清小麦屿临海站位显示潮汐涨落与γ辐射空气吸收剂量率升降存在显著的反相位规律；在小时尺度上，福清小麦屿站位的降雨事件将大气中²²²Rn子体²¹⁴Pb和²¹⁴Bi清除至地表，并导致γ辐射空气吸收剂量率短期内骤然升高.

Mechanism of the variable γ radiation air absorbed dose rate in the atmosphere

In this study, the high-frequency and long-term continuous monitoring data of the γ radiation air absorbed dose rate nearby the three nuclear power plants in Guangxi(Fangchenggang City) and Fujian(Fuqing City and Ningde City) Province was comprehensively discussed from the perspective of different time scales to explore the variable characteristics and regulation mechanism of the γ radiation air absorbed dose rate. At the interannual scale, the γ radiation air absorbed dose rate had a reverse relationship with solar activity on the basis of long term monitoring at Yushandao station in Ningde City from 2014 to 2020. At the seasonal scale, the East Asian monsoon dominantly contributed to the seasonal characteristics of low in summer and high in winter for the γ radiation air absorbed dose rate. At the diurnal scale, tide significantly affected the diurnal fluctuations of the γ radiation air absorbed dose rate. At the hour scale, rainfall event would remove the radon progenies of ²¹⁴Pb and ²¹⁴Bi from the atmosphere to the surface soil, leading to a sudden increase in the γ radiation air absorbed dose rate.