Evaluation of Upper Atmospheric Ozone Data provided by a Differential-Absorption Lidar

Abstract

Ground-level ozone is an environmental and public health issue. Daily ozone forecasts are made to allow people to take precautions to protect their health. For this study, a prototype laser that measures ozone concentrations vertically throughout the atmospheric boundary layer was evaluated as tool for ozone forecasting.

To examine this data, three analyses were performed. First, it was determined if stratification, and thus residual layers, could be seen. This was conducted, in part, by examining hourly mixing heights overlaid onto color-coded NEXLASER charts. Each NEXLASER chart shows the horizontal and spatial distribution of the measured ozone concentrations during a twenty-four hour period. In the second analysis, the correlation value between the early morning upper-tropospheric ozone and the maximum 8-hour average surface ozone concentrations was determined. For the third analysis, a case study on two select groups of days was conducted.

This study suggested that NEXLASER can be used to detect the presence of residual layers and can be used as an aid in predicting peak daily 8-hour average ground-level ozone concentrations. Specifically, days on which a morning ozone reservoir layer is most prominent have the most potential to lead to high surface ozone concentrations later in the day. While more research should be conducted, this study shows how this data could be useful in explaining ozone events, and thus be an aid to ozone forecasters.