Upper Green Winter Ozone Study


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

UGWOS 2007 QA Plan Documents
2007 QA Plan
Appendix A
Appendix B
UGWOS 2007 Database Revised 7/30/2008 (.zip)

UGWOS 2008 QA Plan
UGWOS 2008 Database 8/04/2008 (.zip)
UGWOS 2008 Final Report

UGWOS 2009 QA Plan
UGWOS 2009 Database 06/25/2009 (.zip)
UGWOS 2009 Final Report

UGWOS 2010 QA Plan
UGWOS 2010 Database (.zip)
UGWOS 2010 Final Report

UGWOS 2011 QA Plan
UGWOS 2011 Database (.zip)
UGWOS 2011 Final Report
UGWOS 2011 Weather Comparison

UGWOS 2012 QA Plan
UGWOS 2012 Database (.zip)
UGWOS 2012 Final Report

UGWOS 2013 QA Plan
UGWOS 2013 Database (.zip)
UGWOS 2013 Final Report

UGWOS 2014 QA Plan
UGWOS 2014 Database (.zip)
UGWOS 2014 Final Report