HAQAST1 Meeting 11/4/2016 Satellite-based products and tools to support quantification and attribution of background ozone Jessica Neu, Greg Osterman, Kevin Bowman, Dejian Fu NASA Jet Propulsion Laboratory, California Institute of Technology In Collaboration with the South Coast Air Quality Management District and California Air Resources Board Background Ozone Limits the Achievable Health Benefits of Emissions Reductions. New EPA Threshold (70 ppb) EPA Background (40 ppb) Range based on observations [Lefohn et al., 2001] Model Range from Fiore et al.[2014] Global Model Range First box. In a recent paper led by Willem Verstraeten, we looked at changes in ozone over Eastern China and the Western US from 2005-2010. Using data from the Tropospheric Emission Spectrometer, we saw…Using OMI NO2 measurements with the TM5 model, we found that NOx emissions had increased by 21% and decreased by 21%. The increase in emissions explained half of the ozone increase, while MLS measurements showed that the other half as associated with natural variability in strat transport, talk more about in a minute. Over the Western US, transport from China offset….. Adapted from Burnett et al., 1994

Using Satellite Data to Aid Quantification and Attribution of Background Ozone Changes in the Western US OMI+TES: Background Ozone was as high as 65 ppb during intense wildfires in 2006 Wildfires: Regional Model with Emissions Inversion and Assimilated Boundary Conditions Satellite Measurements of ozone and NO2 have been successfully used with global and regional models to assess the processes that control background ozone Huang et al., JGR, 2015 Long-Range Transport and Stratosphere-Troposphere Exchange: Global Model with Emissions Inversion and Stratospheric Correction OMI: 21% increase in NOx emissions. Explains 50% of the ozone increase. Explains 50% of the ozone increase TES: 7% Increase in mid-tropospheric ozone TES: No change in mid-tropospheric ozone OMI: 21% decrease in NOx emissions. Should have given a 2% decrease in ozone Offset 57% of expected ozone decrease Transport from China offset 43% of expected decrease MLS: Temporary increase in downward transport from the stratosphere partly due to 2009-2010 El Nino. First box. In a recent paper led by Willem Verstraeten, we looked at changes in ozone over Eastern China and the Western US from 2005-2010. Using data from the Tropospheric Emission Spectrometer, we saw…Using OMI NO2 measurements with the TM5 model, we found that NOx emissions had increased by 21% and decreased by 21%. The increase in emissions explained half of the ozone increase, while MLS measurements showed that the other half as associated with natural variability in strat transport, talk more about in a minute. Over the Western US, transport from China offset….. Verstraeten et al., Nature Geoscience, 2015

Work Proposed Under HAQAST Analyze how background ozone has responded to changes in international emissions (particularly those from East Asia) as well as to natural variability in long-range transport and stratosphere-troposphere exchange over the past ~10 years. Ozone over East Asia, 2004-2014   Use assimilated satellite measurements to generate ozone lateral and upper boundary conditions for regional models. First box. In a recent paper led by Willem Verstraeten, we looked at changes in ozone over Eastern China and the Western US from 2005-2010. Using data from the Tropospheric Emission Spectrometer, we saw…Using OMI NO2 measurements with the TM5 model, we found that NOx emissions had increased by 21% and decreased by 21%. The increase in emissions explained half of the ozone increase, while MLS measurements showed that the other half as associated with natural variability in strat transport, talk more about in a minute. Over the Western US, transport from China offset….. 300 hPa 680 hPa Generate regional maps of tropospheric ozone profiles to aid in exceptional event analysis.