Near ground gamma-ray measurement associated with weather

Abstract

The objective of this study is to search for the cause of lightning induced gamma-rays and the correlation between gamma-rays from Pb-214 and Bi-214 and meteorological changes. An increase in the gamma-ray rate in the vicinity of the near ground detector was first observed in 2002 when lightning occurred without precipitation, and is likely to be induced by the lightning since it could not explained by the rain precipitation. Some other observations of the increase of the gamma-rays with lightning was suggested, and Bremsstrahlung was discussed as a possible cause. It is needed to exclude the influence on gamma-rays from rain since lightning without rain precipitation rarely happens. The model was used, which was useful to demonstrate the increase in gamma-rays from Pb-214 and Bi-214 from the rain, and it showed a slight phase shift when the lightning occurred too. The measurement was statistically poor for lightning, but is suggesting the possibilities.