Measurement of space charge density over flat ground in nearly neutral stratified atmospheric surface layer

Abstract

Space charge density and alpha-activity profiles were measured simultaneously at a 0-1.6 m layer above the ground. Measurements were obtained with one instrument to measure alpha-activity profile and with two Obolensky filters to measure space charge density where one Obolensky filter was used as a reference instrument. Theoretical space charge profiles were calculated with the electrode effect model given by Tuomi (1982) and they were compared with experimental profiles measured. From the analysis of the recordings, the electrode effect was observed. The agreement between theoretical and experimental results has been discussed. Best agreement between the theoretical and experimental results was obtained for the height variation between 0.2-0.8 m when the ionization rate is constant.

空間電荷密度およびα活動度分布を、地上0-1.6m層で同時に測定した。測定値は、α活動度分布を測定する1つの計測器と、空間電荷密度を測定するための、1つを基準計測器として用いる2つのObolenskyフィルタによって得た。理論的な空間電荷分布は、Tuomi(1982)によって与えられた電極効果モデルで計算され、それらを測定した実験分布と比較した。記録の解析から、電極効果が観察された。理論と実験の結果の一致を検討した。理論と実験の結果の最も良い一致は、イオン化率が一定であるとき、高さが0.2-0.8mに変化するときに得られた。