1 / 12

North America as a Source and Receptor of Hemispheric Ozone Pollution: Variability, Uncertainties, and Policy Implicatio

This study explores the seasonal variability, uncertainties, and policy implications of North America's role in both emitting and receiving hemispheric ozone pollution. It quantifies the surface ozone response to regional and foreign anthropogenic emissions and provides valuable insights for future research and policy-making.

donnasullivan
Download Presentation

North America as a Source and Receptor of Hemispheric Ozone Pollution: Variability, Uncertainties, and Policy Implicatio

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. North America as a Source and Receptor of Hemispheric Ozone Pollution: Seasonal Variability, Uncertainties, and Policy Implications Arlene M. Fiore A33-E01 F.J. Dentener, C. Cuvelier, M.G. Schultz, O. Wild, T.J. Keating, A. Zuber, S. Wu, C. Textor, M. Schulz, C. Atherton, D.Bergmann, I. Bey, G. Carmichael, R. Doherty, B. Duncan, G. Faluvegi, G. Folberth, M.G. Vivanco, M. Gauss, S. Gong, D. Hauglustaine, P. Hess, T. Holloway, L. Horowitz, I. Isaksen, D. Jacob, J. Jonson, J. Kaminski, A. Lupu, I. MacKenzie, E. Marmer, V. Montanaro, R. Park, K. Pringle, J. Pyle, M. Sanderson, S. Schroeder, D. Shindell, D. Stevenson, S. Szopa, R. Van Dingenen, P. Wind, G. Wojcik, G. Zeng Joint Assembly, Fort Lauderdale, FL, May 28, 2008

  2. Wide range in prior estimates of intercontinentalsurface ozone source-receptor (S-R) relationships NORTH AMERICA  EUROPE ASIA  NORTH AMERICA annual mean events events seasonal mean Surface O3 contribution from foreign region (ppbv) seasonal mean annual mean Studies in TF HTAP [2007] + Holloway et al., 2008; Duncan et al., 2008; Lin et al., 2008 Assessment hindered by different (1) methods, (2) reported metrics, (3) meteorological years, (4) regional definitions Few studies examined all seasons A.M. Fiore

  3. Objective: Quantify & assess uncertainties in N. mid-latitude S-R relationships for ozone TF HTAP REGIONS BASE SIMULATION (21 models):  horizontal resolution of 5°x5° or finer  2001 meteorology  each group’s best estimate for 2001 emissions  methane set to 1760 ppb SENSITIVITY SIMULATIONS (13-18 models):  -20% regional anthrop. NOx, CO, NMVOC emissions, individually + all together (=16 simulations)  -20% global methane (to 1408 ppb) A.M. Fiore

  4. Simulated vs. observed monthly mean surface O3 EASTERN USA CENTRAL EUROPE OBS (EMEP) MODELS MODEL ENS. MEAN Surface Ozone (ppb) OBS (CASTNet) Seasonal cycle captured over Europe Month of 2001 High bias over EUS in summer and early fall • Greater uncertainty in results for summertime NA A.M. Fiore

  5. North America as a receptor of ozone pollution: Annual mean foreign vs. domestic influences Source region: ∑ 3 foreign = 0.45 domestic Seasonality? Annual mean surface O3 decrease from -20% NOx+CO+NMVOC regional anthrop. emissions (1.64) Full range of 15 individual models “import sensitivity” ppbv “domestic” “Sum 3 foreign” A.M. Fiore

  6. North America as a receptor of ozone pollution: Seasonality of response to -20% foreign anthrop. emissions Spring max Similar response to EU & EA emissions Apr-Nov (varies by model) SUM OF 3 FOREIGN REGIONS 15- MODEL MEAN SURFACE O3 DECREASE (PPBV) EA EU SA Spring (fall) max due to longer O3 lifetime, efficient transport [e.g., Wang et al., 1998; Wild and Akimoto, 2001; Stohl et al., 2002; TF HTAP 2007] A.M. Fiore

  7. North America as a receptor of ozone pollution:Seasonality of response to -20% foreign anthrop. emissions Comparable response to NOx & NMVOC emissions (but varies by model) NOx+NMVOC+CO MODEL ENSEMBLE MEAN SURFACE O3 DECREASE (PPBV) NMVOC NOx CO Wide range in EU anthrop. NMVOC inventories  large uncertainty in the estimated response of NA O3 A.M. Fiore

  8. North America as a receptor of ozone pollution: Seasonality in “import sensitivity” IMPORT SENSITIVITY: ∑ (-20% 3 foreign) -20% domestic ~0.2 when domestic O3 production peaks in summer 0.4-0.8 during spring “high transport season” Surface O3 response to -20% domestic (NA NOx+NMVOC+CO) anthrop. emis. Response to -20% Foreign > Domestic (winter) PPBV RATIO A.M. Fiore

  9. North America as a source of ozone pollution Similar impact from 3 foreign regions Largest foreign S-R pair Annual mean surface O3 decrease from -20% NOx+CO+NMVOC regional anthrop. emissions Source region: sum of 3 foreign regions Full range of 15 individual models Receptor region: NAEUE AsiaS Asia Import sensitivity: 0.45 0.75 0.65 0.45 A.M. Fiore

  10. Surface ozone response to -20% global [CH4]:similar decrease over all regions Full range of 18 models ppb 1 ppbv O3 decrease over all regions [Dentener et al.,2005; Fiore et al., 2002, 2008; West et al., 2007] EU NA E Asia S Asia • Estimate O3 response to -20% regional CH4 anthrop. emissions to • compare with O3 response to NOx+NMVOC+CO: • -20% global [CH4] ≈ -25% global anthrop. CH4 emissions • Anthrop. CH4 emis. inventory [Olivier et al., 2005] for regional emissions • Scale O3 response (linear with anthrop. CH4 emissions [Fiore et al., 2008]) A.M. Fiore

  11. Comparable annual mean surface O3 response to -20% foreign anthropogenic emissions of CH4 vs. NOx+NMVOC+CO Sum of annual mean ozone decreases from 20% reductions of anthropogenic emissions in the 3 foreign regions ppb Receptor: NA EU E Asia S Asia (Uses CH4 simulation + anthrop. CH4 emission inventory [Olivier et al., 2005] to estimate O3 response to -20% regional anthrop. CH4 emissions) A.M. Fiore

  12. Conclusions: S-R relationships for O3 pollution • Benchmark for future: Robust estimates + key uncertainties Robust: NAEU largest; SAothers smallest Uncertainties: Model transport, emissions, chemistry particularly NA in summer, EU/EA -> NA, NOx/NMVOC -> NA • NA response to foreign anthrop. emissions 40-80% that to domestic anthrop. emissions in spring and late fall • Reducing equivalent % of CH4 yields an O3 decrease similar to that achieved with NOx+NMVOC+CO over foreign regions (0.4-0.6 ppb for 20% reductions) www.htap.org for 2007 TF HTAP Interim Report and information about TF HTAP activities A.M. Fiore

More Related