Officials are asking Basin residents to please reduce ozone-forming emissions as much as possible for the next few days after an unexpected ozone jump. “Yesterday afternoon/early evening, ozone at Ouray unexpectedly jumped over the EPA standard, with an 8-hr average of about 73 parts per billion (ppb),” shares Dr. Seth Lyman, Director of the USU Bingham Energy Research Center. “We had been watching it climb, but the big leap yesterday caught us off guard. The tail end of a weak storm pushed some pollution out of the Basin last night, but not completely, so another day or days of high ozone is still possible.” Lyman explains that this is the first exceedance day of 2021, and the first wintertime exceedance in about 22 months. It was only the Ouray station that exceeded the standard but ozone is climbing at other sites and exceedances at other locations are possible. “The Basin is pretty strongly inverted right now, but particulate haze in the cities and ozone in the central Basin cleared out partially [Tuesday] night nonetheless,” continues Lyman. “The atmosphere is predicted to stay slightly unstable over the next few days, but it’s not clear at all whether it will be enough to keep pollution mixed out, or whether pollution will continue to build to another ozone exceedance. We recommend reducing emissions to the extent possible during this uncertain time. We will send another email when/if the short-term danger of winter ozone passes.” In the meantime, all are encouraged to keep tabs on the latest data on the Twitter feed (@uairquality) or Web App, https://ozonealert.usu.edu/.
