EGU23-7163, updated on 25 Feb 2023
https://doi.org/10.5194/egusphere-egu23-7163
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under the Creative Commons Attribution 4.0 License.
Decreasing trends in extreme ozone events across the United States
- 1CIRES, University of Colorado Boulder and NOAA Chemical Sciences Laboratory, Boulder, United States of America (kai-lan.chang@noaa.gov)
- 2CIRES, University of Colorado Boulder and NOAA Chemical Sciences Laboratory, Boulder, United States of America (owen.r.cooper@noaa.gov)
This work presents a comprehensive regional trend analysis of surface ozone observations across the contiguous United States, using 25 years of data from 62 rural monitoring sites, and based on quantile regression and change point analysis. We highlight that the ozone exceedance events (based on the daily maximum 8-hour average and a threshold of 70 ppb) in recent years (2017-2021) are largely diminished compared to two decades ago (1995-2003) in the eastern US and across much of the western US. Ozone exceedance events in recent years are mainly observed in California during the fire season. Results based on thresholds of 60, 50 and 35 ppb will also be discussed.
How to cite: Chang, K.-L. and Cooper, O.: Decreasing trends in extreme ozone events across the United States, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7163, https://doi.org/10.5194/egusphere-egu23-7163, 2023.
