Atmospheric chemistry analysis and modeling at LDEO: Connecting global composition, climate, and air quality Atmos. Chem at CU Group Meeting 9-19-13 Arlene M. Fiore 83520601 Group members : Olivia Clifton (CU), Gus Correa (LDEO), Jean Guo (CU), Nora Mascioli (CU), Keren Mezuman (CU), Lee Murray (LDEO), Luke Valin (LDEO) Close Collaborators : Elizabeth Barnes (now at CSU), Larry Horowitz (GFDL), Meiyun Lin (Princeton/GFDL), Vaishali Naik (UCAR/GFDL), Jacob Oberman (former NOAA Hollings intern), Harald Rieder (now at U Graz, Austria), Lorenzo Polvani (CU), Mike Previdi (LDEO)
Atmospheric chemistry analysis and modeling at LDEO: Connecting global composition, climate, and air quality. Arlene M. Fiore. Group members : Olivia Clifton (CU), Gus Correa (LDEO), Jean Guo (CU), Nora Mascioli (CU), Keren Mezuman (CU), Lee Murray (LDEO), Luke Valin (LDEO) - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Atmospheric chemistry analysis and modeling at LDEO: Connecting global composition, climate, and air quality
Atmos. Chem at CUGroup Meeting
9-19-13
Arlene M. Fiore
83520601
Group members: Olivia Clifton (CU), Gus Correa (LDEO), Jean Guo (CU), Nora Mascioli (CU), Keren Mezuman (CU), Lee Murray (LDEO), Luke Valin (LDEO)
Close Collaborators: Elizabeth Barnes (now at CSU), Larry Horowitz (GFDL), Meiyun Lin (Princeton/GFDL), Vaishali Naik (UCAR/GFDL), Jacob Oberman (former NOAA Hollings intern), Harald Rieder (now at U Graz, Austria), Lorenzo Polvani (CU), Mike Previdi (LDEO)
Today’s Focus
How and why might extreme air pollution events change?
All AQAST projects connect Earth Science and air quality management: active partnerships with air quality managers with deliverables/outcomes self-organizing to respond quickly to demands flexibility in how it allocates its resources INVESTIGATOR PROJECTS (IPs): members adjust work plans each year to
meet evolving AQ needs “TIGER TEAM” PROJECTS (TTs): multi-member efforts to address
Our projects for 2013• Stratospheric and Asian influence on inter-annual WUS surface O3 variations (M. Lin)• climate versus emissions impacts on 21st C U.S. baseline O3 (seasonality)• Analysis of background O3 influence on O3 measured at new NV sites (M. Lin).
TTs (pending selection)• (PIs: Fiore, Holloway) Source attribution for high-O3 events over EUS• (PI: Streets) Satellite-derived NOx emissions and trends• In progress: Multi-model W126 analysis (vegetation exposure)• In progress: Estimates of background O3 from 2 models
www.aqast.org: click on “projects” for brief descriptions + link to pdf describing each project
What makes AQAST unique?How is our group contributing?
Surface O3 seasonal cycle over NE USA reverses – cold season increases- under extreme warming scenario (RCP8.5)
in the GFDL CM3 model
NOx
decreases
?
Monthly mean surface O3 (land only) over the NE USA (36-46N, 70-80W)pp
b
month
3 ensemble members for each scenario
O. Clifton
Why does surface O3 increase in winter/spring over NE USA under RCP8.5?
Change in monthly mean surface O3 (land only) over the NE USA (36-46N, 70-80W)(2091-2100) – (2006-2015)
ppb NOx
decreases
RCP8.5 (3 ensemble members)
?
O. Clifton
Doubling methane raises surface O3 over NE USA ~5-10 ppb
Change in monthly mean surface O3 (land only) over the NE USA (36-46N, 70-80W)(2091-2100) – (2006-2015)
ppb
RCP8.5 but chemistry sees 2005 CH4
RCP8.5 (3 ensemble members)
Doubling CH4
does not fully explain wintertime increase
O. Clifton
Will the NE USA resemble present-day remote, high-altitude W US sites by 2100?
Setting achievable standards requires accurate knowledge of background levels
120 ppb 1979 1-hr avg
84 ppb1997 8-hr
75 ppb 2008 8-hr
40 60 80 100 120O3 (ppbv)
20
U.S. National Ambient Air Quality Standard for O3 has evolved over time
Future?(proposed)
typical U.S.“background” (model estimates)[Fiore et al., 2003;Wang et al., 2009;Zhang et al., 2011]
Allowable O3 produced from U.S. anthrop. sources (“cushion”)
Lowering thresholds for U.S. O3 NAAQS implies thinning cushion between regionally produced O3 and background
backgroundevents over WUS
[Lin et al., 2012ab]
2008 O3 NAAQS revision relied on background estimates from one model Compare N. Amer Background in GFDL AM3 vs. GEOS-Chem
AM3 (~2°x2°) GEOS-Chem (½°x⅔°)
Fourth-highest North American background MDA8 O3 in model surface layer between Mar 1 and Aug 31, 2006
ppb
Estimates of North American background in 2 models (simulations with N. American anth. emissions set to zero)
Models robustly agree N. American background is higher at altitude in WUS Multi-model enables error estimates, in context of observational constraints Need to account for biases to estimate useful policy-relevant statistics
Higher background (spring):More exchange with surface?Larger stratospheric influence?
35 42 50 57 65
High AM3 bias in EUS;caution on N. Amer. Background here!
Excessive lightning NOx in summer
J. Oberman
Fiore et al., in prep
Connecting atmospheric composition, climate, and air quality: from background oxidation to extreme pollution events
• Variability in background CH4 oxidation (OH) Space-based constraints from formaldehyde columns? Determine key driving factors (multi-model CMIP5/ACCMIP)
Extend to other regions, seasons, with a focus on extremes Develop robust relationships with changes in meteorology +
feedbacks from the biosphere
• “Climate penalty” can be offset by NOx reductions which preferentially decrease the highest O3 events
• Background ozone and its specific sources over the U.S. Future shifts in regional vs. transported ozone (incl. CH4)? Harnessing power of multiple models + observations Variability on scales from daily to multi-decadal Process-oriented analysis (Asian polln, strat, storms, jets)
• New Directions Role of aerosol forcing on extreme weather events Process studies (lightning NOx, deposition) Climate variability and composition
Change in 1-yr O3 RL: (2091-2100) – (2046-2055)
Change in monthly mean NE USA O3 : (2091-2100) – (2006-2015)