1947 年 23 巻 1-12 号 p. 35-37
The variation of the atmospheric potential gradient during the dust storm has been recorded at Maebashi Meteorological Observatory. The results of observations during the period from January to May, 1943 were described in the first report of this paper with some discussions. In that season, the variation was almost in the positive side during the period from January to March, while in April the variaticn fluctuated in both positive and negative sides, and in May the variation was almost in negative side. In this paper the results of observations during the period from December, 1943, to May, 1944, are described. The variation of atmospheric potential gradient in December, 1943, was almost in positive side, while it fluctuated in both positive and negative sides during the period from February to the beginning of April, and it was almost in negative side during the period from the middle of April to May. The seasonal variation of them resembles to that of the former year. The range of the variation exceeds 2000 volt per metre at most. So the density of the space charge in the dust storm is in the order of 1 esu/m3 at most as described in the first report.