Mitigating ozone pollution involves reducing ozone production and relies on complex air-quality models
to design reduction strategies and determine their effectiveness. However, modeled ozone does not
always agree with observations. A complementary approach is to measure the ozone production rate
directly, leading to the development of the Measurement of Ozone Production Sensor (MOPS). Two
improved second-generation MOPSv2s were deployed for NASA's DISCOVER-AQ field campaign in
September 2013 at the University of Houston, 5 km south of downtown, and Smith Point, at the mouth of
the Houston Ship Channel. Median September P(O3) was low, consistent with the observed ambient
ozone. The MOPSv2s provided statistically similar results when they were compared for 8 day sat the
University of Houston. October measurements yielded a median ozone production rate of
27 ± 11 ppbv hr1, falling within the range of calculated P(O3) from prior Houston field campaigns in
2006 and 2009. Additionally, diurnal patterns are similar to model-derived ozone production from these
previous campaigns. An advection analysis for a high ozone event on 25 September 2013 indicates that
the Houston site was in a local ozone source region, while Smith Point ozone was likely enhanced by
transport from other areas.