Winter Ozone Study
CAUTION: SOME FILES MAY BE IN EXCESS OF 5 MB
In the winters of 2005 and 2006, primarily in the month of February, the Wyoming Department of Environmental Quality - Air Quality Division (AQD) measured 8-hour ozone concentrations greater than 80 ppb at the Daniel South, Jonah and Boulder monitoring stations. Elevated ozone concentrations are uncommon during the winter months; however, they do not appear to be an anomaly because these conditions were recorded in both February 2005 and February 2006. For the 2007 winter months, AQD contracted with Environ International (subcontractors T&B Systems, Sonoma Technology Inc., and Meteorological Solutions Inc.) to perform a study of ozone formation in the Upper Green River Basin. The 2007 Quality Assurance (QA) Plan can be downloaded below.
During the 2007 study, meteorological conditions did not set up as they had in 2005 and 2006, and therefore, elevated ozone was not monitored. However, the parameters that were monitored were validated and can be used to gain insight into this unique winter formation of ozone in the Upper Green River Basin. Data from the 2007 campaign can be downloaded below.
Because of the mild winter in 2007, funds were left to perform the study again in 2008. AQD and our contractors modified the study plan based on available funding and lessons learned during the 2007 study. The 2008 QA Plan can be downloaded below. During February and March 2008 several days of elevated ozone were monitored. The 2008 study data are available below. After the winter of 2008, AQD determined there were still aspects of the winter formation that needed to be recorded and studied.
AQD continued various portions of the study during the 2009 and 2010 winter seasons. In 2009, AQD added trace gas parameters and NOy1 monitoring in addition to increasing the number of mesonet2 stations in the Upper Green River Basin. In 2010, a nitrous acid (HONO) measurement replaced the NOy monitoring. February and March 2009 and 2010 had fewer days conducive to ozone formation than 2008. Additionally, elevated ozone periods were shorter in duration than in previous years. The 2009 and 2010 Quality Assurance Project Plans (QAPPs) and study data are available below.
In 2011, the AQD consulted with its Technical Advisory Group (TAG) to
further focus winter monitoring in support of developing a photochemical
grid model for wintertime ozone formation. As a result of these
discussions, the primary focus of the 2011 winter monitoring was the
vertical distribution of precursors. HONO data was also collected
in 2011. In 2012 and 2013, the program was scaled back to
long-term monitoring stations plus a monitoring station in the Jonah
Field and speciated VOCs at various locations. The most recent
study for 2014 is now available below.
The 2014 program included the long-term stations, a mobile
station in the Jonah Field, plus three mesonet stations that collected
ozone, meteorology, VOC canisters, and cartridges for formaldehyde and
acetaldehyde. The data can be downloaded below. Please note
these data have been fully quality assured. Also note there can be
issues when translating these data into an MSAccess database; therefore,
the database has been versioned in the event that translation errors are
found. For more information you can contact Cara Keslar,
Monitoring Section Supervisor, at (307)777-8684.
1 the sum of all total reactive nitrogen oxides, including NO, NO2, and other nitrogen oxides referred to as NOZ
2 solar powered tripod monitoring station used for wind and ozone measurements
Upper Green Winter Ozone Study Downloads