Measurement of Ozone Concentration on the Elevation Gradient of a Low Hill by a Semiconductor-Based Portable Monitor

Abstract: Ozone concentration has a complex distribution in mountain areas, but the low spatial density of high elevation monitoring stations has limited our understanding of ozone behavior. To achieve high spatial density, mobile measurement was carried out using a portable ozone monitor based on a semiconductor sensor. On the elevation gradient of a relatively low hill (273 m above seal level) in Matsuyama, Japan, 66 walking measurements were conducted in the pre-dawn hours of the winter in 2012 and 2013. The ozone concentration at the top of the hill was positively correlated with the daily maximum concentration on the plain on the previous day. The difference in ozone concentration between the top and bottom of the hill was found to increase with increasing vertical temperature difference. The measurement method established in this study provides a low-cost alternative to grasp the distribution of ozone in mountain areas.