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Air Quality and Climate Change. Weather has a large effect on U.S. air quality. Loretta Mickley Harvard University. What U.S. city is this?. Co-authors: Amos Tai, Eric Leibensperger , and Xu Yue, Daniel Jacob, Jennifer Logan. U.S. Air Quality Smog Blog, alg.umbc.edu / usaq.
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Air Quality and Climate Change Weather has a large effect on U.S. air quality. Loretta Mickley Harvard University What U.S. city is this? Co-authors: Amos Tai, Eric Leibensperger, and Xu Yue, Daniel Jacob, Jennifer Logan U.S. Air Quality Smog Blog, alg.umbc.edu/usaq
Weather has a large effect on U.S. air quality. Jan 23, 2013 warmer cooler Salt Lake City Persistent temperature inversions this January over Northern Utah led to unhealthy air 11 out of 31 days. Airnow; NASA Earth Observatory
Both emissions and weather have been changing over the United States. OMI NO2 data Thanks to Bryan Duncan
Temperatures have been increasing rapidly since the 1980s. Contiguous US 1 0 Temperature anomaly (o C) Warming trend after 1980 -1 2000 1880 What do these trends mean for surface air quality? NASA GISS temperature analysis, GISTEMP
Number of ozone exceedances in Chicago and St. Louis looked promisingly low in recent years. Chicago Number of days MDA8 ozone > 75 ppb www.epa.gov/airdata/ad_viz_ozcompare.html St. Louis Airnow
Drought + heat wave in 2012 ramped up number of ozone exceedances. Chicago Number of days MDA8 ozone > 75 ppb www.epa.gov/airdata/ad_viz_ozcompare.html St. Louis Airnow
We know that surface ozone is sensitive to stagnation. Stagnant air covers East. Clear skies. High temperatures. Cold front moves through. Cool, clean air. Leibensperger et al., 2010
Cold fronts clear away pollution in central and eastern United States. Clean air High ozone levels Leibensperger et al., 2010
Cyclones passing through Great Lakes/ Southern Canada region are associated with cold fronts . Cyclone Stagnant air. Cold front moves through. Leibensperger et al., 2010
Climate models predict decreasing trend in number of Great Lakes cyclones in warming atmosphere. 30% decrease RCP 8.5 Number of cyclones over Great Lakes region Climate model projection of JJA cyclone number over Great Lakes region. Turner et al., 2013
Climate models predict more persistent weather in future atmosphere over mid-latitudes. What are the implications for air quality? As high latitudes warm, slower eastward progression of Rossbywaves in the upper-level flow. Francis et al., 2012
Climate penalty for ozone air quality: Increased stagnation + high temperatures will likely increase surface ozone. D MDA8 JJA ozone 2000-2050 change in JJA MDA8 ozone due to climate change. -4 -2 0 2 4 6 ppb ppb Climate generated by NASA GISS Model 3; Tai et al., 2013
Response of PM2.5 to changing meteorology is more complicated. Observed sulfate correlates with temperature, but . . . . nitrate anti-correlates with temperature. Observed relationships with Temperature (% K-1) Tai et al., 2010
Net effect of 2000-2050 climate change on PM2.5 is small, at least when considering circulation changes. Dannual mean PM2.5 2000-2050 change in annual mean PM2.5 due to changing circulation. Increased maritime flow Increased stagnation Changes are small, on the order of 0.5 mg m-3. Tai et al., 2012
Wildfires may become the dominant player in changing PM2.5 in future atmosphere. Modeled 2050s response of surface PM2.5 to trends in circulation and in wildfires. Tai et al., 2012; Yue et al., 2013
Doubling of wildfire activity in warmer and drier 2050s significantly increases PM2.5 in the western U.S. D organic PM2.5 2000-2050 change in JJA mean organic carbon particles due to changing wildfires. NASA GISS Model 3; Yue et al., 2013
Increase in organic PM2.5 in 2050s is especially large during extreme wildfire events. Cumulative probability of daily mean concentrations of organic particles 2050s Projection shows doubling of organic particles during fire events over Rocky Mountains in May-October timeframe for the 2050s. doubling Present-day NASA GISS Model 3; Yue et al., 2013
Take home message 1 The response of air quality to climate change depends on trends in extreme events: stagnation, inversions, or wildfires. warmer Persistent temperature inversions this January over Northern Utah led to unhealthy air 11 out of 31 days. cooler Salt Lake City Airnow; NASA Earth Observatory
Take home message 2: The climate penalty for ozone air quality could be large. D MDA8 JJA ozone 2000-2050 change in MDA8 JJA ozone due to climate change. -4 -2 0 2 4 ppb NASA GISS Model 3; Tai et al., 2013
Take home message 3: Air quality in the West is vulnerable to changing wildfire in a warmer, drier climate. Cumulative probability of daily mean concentrations of organic particles 2050s doubling Projection shows doubling of organic particles during wildfires over Rocky Mountains in 2050s. Present-day NASA GISS Model 3; Yue et al., 2013