In their new paper, Dan Jaffe and Lei Zhang describe what might be the most unusual meteorological event in decades--a very unusual climate pattern that caused elevated ozone levels in Washington, Oregon, western Utah, and northern California during June 2015. Published in Geophysical Research Letters, a journal of the American Geophysical Union, their research observed that warm temperatures, low cloud cover, and calm air led to extremely high ozone measurements. These elevated measurements were recorded at Mount Bachelor Observatory (MBO) and at monitoring stations around the western US. In fact, the June 2015 measurements were the highest ever recorded at MBO since it began operation in 2004. The high ozone concentrations negatively impacted air quality across the western US, especially in Salt Lake City and Sacramento, which recorded several days of ozone levels above the federal limit set by the Environmental Protection Agency.
It is generally understood that warmer temperatures favor ozone production. However, this study suggests that broader climate patterns also play a role in air quality and human health. “Our environmental laws need to be written with an understanding that there’s a lot of variability from one year to the next, and with an understanding of the long-term path of where we’re heading under climate change,” Jaffe said. “This work helps us understand the link between climate variability and air quality, and it can give us an idea of what to expect as our planet continues to warm.”
Read more on UW Today
Read more on KUOW
Read the full paper in Geophysical Research Letters
Caption: Data showing large changes in ozone (O3) for June 2015. (a) Average of all ozone data from MBO for June for 2004–2015, (b) June 2015 mean ozone measurements from EPA Air Quality System (AQS) stations, and (c) average of June ozone measurements for previous 5 years. In Figure 1b a star is used to show location of the MBO and EPA AQS sites are shown with dots.