Measurements of atmospheric hydroperoxides at a rural site in central Japan

摘要

Measurements of hydroperoxides (H2O2 and MHP) at ground level were made from 2012 to 2015 in Imizu City, Toyama Prefecture in central Japan. H2O2 and MHP concentrations ranged from 0.01 to 3.5 ppb and from below the level of detection ( 0.01 ppb) to 1.4 ppb, respectively. The concentrations of H2O2 and MHP were high in the summer and low in the winter. The H2O2 concentration was at its maximum in July and August, whereas the concentration of O-3 in the daytime was highest in May and June. The ratio of [H2O2]/[SO2] presented clear seasonal variations. Many cases showed the condition of [H2O2] [SO2], called oxidant limitation especially in the cold months. Hydroperoxide concentrations in the rainwater were also high in the summer. The concentrations of MHP were much lower than those of H2O2 in the rain water. High concentrations of H2O2 ( 2.5 ppb) were detected in the summer during the inflow of air pollution. The concentrations of H2O2 were significantly high in July and August of 2013. The H2O2 was well correlated with the O-3 in July and August whereas there was no correlation between O-3 and H2O2 in May and June. There was a negative correlation between NOX and H2O2.