1-h avg..pptVIP

* * * * * * * * * * * AIR QUALITY AND CLIMATE TOPICS FOR TODAY What are we worried about when we talk about “air quality” Global air quality Background interhemispheric transport Local/regional air quality Nitrogen oxide radicals; NOx = NO + NO2 combustion, soils, lightning Methane wetlands, livestock, natural gas Nonmethane volatile organic compounds (NMVOCs) vegetation, combustion, industry CO (carbon monoxide) combustion, VOC oxidation O3 O2 hn O3 OH HO2 hn, H2O Deposition NO H2O2 CO, VOC NO2 hn STRATOSPHERE TROPOSPHERE 8-18 km Tropospheric ozone precursors generally limiting transport CLIMATE CHANGE AND TROPOSPHERIC OZONE SENSITIVITY OF SURFACE AIR QUALITY TO METEOROLOGICAL VARIABLES Insights into the effect of climate change on air quality Ozone PM (aerosol) Stagnation Temperature Mixing depth Precipitation Cloud cover Humidity Effect of climate change = = ? ? = ? ? (relative) [Jacob and Winner, 2008] PREDICTIONS OF TEMPERATURE AND PRECIPITATION CHANGES IN THE NH [Jacob and Winner, 2008] Warmer everywhere, but precipitation (humidity, cloudiness, convection) trickier. EFFECT OF CLIMATE CHANGE ON OZONE AIR QUALITY Probability of max 8-h O3 84 ppbv vs. daily max. T Lin et al. [2001] Correlation of high ozone with temperature is driven by stagnation, (2) biogenic hydrocarbon emissions, (3) chemistry Ozone exceedances of 90 ppbv, summer 2003 EFFECT OF CLIMATE CHANGE ON REGIONAL STAGNATION Pollution episodes double in duration in 2050 due to decreasing frequency of cyclones ventilating the eastern U.S; expected result of greenhouse warming. 2045-2052 1995-2002 GISS GCM simulations for 2050 vs. present-day climate using pollution tracers with constant emissions Mickley et al. [2004] summer weather map illustrating cyclonic ventilation of the eastern U.S. TOPICS FOR TODAY What are we worried about when we talk about “air quality” Global air quality Background interhemispheric transport Local/regional air quality EFFECT OF 2000-2050 CLIMATE