1. Air Quality Applied Sciences Team (AQAST)
EARTH SCIENCE SERVING AIR QUALITY MANAGEMENT NEEDS
Earth science resources
Air Quality Management Needs
Pollution monitoring
Exposure assessment
AQ forecasting
Source attribution of events
Quantifying emissions
Assessment of natural and international influences
Understanding of transport, chemistry, aerosol processes
Understanding of climate-AQ interactions
satellites
AQAST
suborbital platforms
models
AQAST

2. AQAST Membership: PIs and Co-Is
Daniel Jacob (leader), Loretta Mickley (Harvard)
Greg Carmichael (U. Iowa)
Dan Cohan (Rice U.)
Russ Dickerson (U. Maryland)
Bryan Duncan, Yasuko Yoshida, Melanie Follette-Cook (NASA/GSFC); Jennifer Olson (NASA/LaRC)
David Edwards (NCAR)
Arlene Fiore (Columbia); Meiyun Lin (Princeton)
Jack Fishman, Ben de Foy (Saint Louis U.)
Daven Henze, Jana Milford (U. Colorado)
Tracey Holloway, Steve Ackerman (U. Wisconsin); Bart Sponseller (Wisconsin DRC)
Edward Hyer, Jeff Reid, Doug Westphal, Kim Richardson (NRL)
Pius Lee, Tianfeng Chai (NOAA/NESDIS)
Yang Liu, Matthew Strickland (Emory U.), Bin Yu (UC Berkeley)
Richard McNider, Arastoo Biazar (U. Alabama – Huntsville)
Brad Pierce (NOAA/NESDIS)
Ted Russell, Yongtao Hu, Talat Odman (Georgia Tech); Lorraine Remer (NASA/GSFC)
David Streets (Argonne)
Jim Szykman (EPA/ORD/NERL)
Anne Thompson, William Ryan, Suellen Haupt (Penn State U.)

3. AQAST organization AQAST supports two types of projects:
Investigator Projects (IPs). These involve typically a single AQAST member working with an air quality management partner;
Tiger Team Projects (TTPs). These involve a collaboration of several AQAST members pooling their expertise to address urgent needs from one or more air quality management partners.
AQAST projects must bridge Earth Science and air quality management:
Focus on use of Earth Science resources
Clear air quality management outcomes
1-year deliverables of value for air quality agencies
AQAST has great flexibility in how it allocates its resources
Members are encouraged to adjust their IPs to the evolving needs of air quality management
The TTPs are redefined yearly to address the most pressing needs
The team is self-organizing and can respond quickly to demands

4. Scope of current AQAST projects (IPs and TTPs)
Partner agency
IC/BC for AQ models
Future satellites
AQ processes
SIP Modeling
Background
AQ-Climate
Forecasting
Monitoring
Emissions
Local: RAQC, BAAQD
State: TCEQ, MDE,
Wisconsin DNR, CARB,
Iowa DNR, GAEPD, GFC
Interstate: EPA Region 8,
LADCO
National: NPS, NOAA,
EPA
Theme
Satellites: MODIS, MISR, MOPITT, AIRS, OMI, TES, GOES
Suborbital: ARCTAS, DISCOVER-AQ, ozonesondes, PANDORA
Models: MOZART, CAM AM-3, GEOS-Chem, RAQMS, STEM, GISS, IPCC
Earth Science resource

5. AQAST bimonthly newsletter subscribe through web site or send me email

6. GEOS-Chem model simulation of background ozone over the US in support of the current ozone ISA and REA
2x2.5
0.5x0.667
Color scale Indicates topography (surface pressure)
0.5o x0.67o resolution for North America, 2o x2.5o global, 48 vertical layers
Driven by NASA GEOS-5 assimilated meteorological data
Detailed mechanistic representation of ozone-NOx -VOC-aerosol chemistry
2006 anthropogenic emissions: NEI05 for US, CAC for Canada, BRAVO (scaled) for Mexico, EMEP for Europe, Streets for East Asia, EDGAR (scaled) for rest of world
Natural sources: lightning (OTD/LIS), fires (GFED2 monthly), soils (Yienger), stratosphere (Linoz)
year simulation; focus on 2006 for evaluation
Zhang et al. [Atmos.Environ., 2011] – DOWNLOAD PDF HERE

7. Four GEOS-Chem simulations
Standard – as described above
US background – no US anthro emissions
NA background - no N.American anthro emissions
Natural – no anthro emissions worldwide
2006 MDA8 ozone at CASTNet sites- with mean (4th highest) inset
For discussion of US background see Wang et al. [2009] (DOWNLOAD PDF)

8. Ozone statistics for the US (CASTNet sites)
Natural: 18 ± 6
PRB: 27 ± 8
Model: 52 ± 12
Obs: 50 ± 13
+ > 1.5 km
Frequency distribution of MDA8 ozone
for March-August 2006
27 ± 6
GEOS-Chem is overall unbiased
PRB is 4 ppb higher than in previous GEOS-Chem versions
Model shows little interannual variability for , neither do observations
40 ± 7
57 ± 10
58 ± 9
Zhang et al. [2011]

9. Model “4th highest” MDA8 ozone in 2006
Annual 4th highest ozone
4th highest PRB value
PRB for annual 4th highest ozone
Background may limit or confuse ability of West to achieve a 60 ppb NAAQS;
no such issue in East
Zhang et al. [2011]

10. Model PRB statistics vs. observed ozone in Intermountain West
Comparison of daily MDA8 ozone concentrations for the ensemble of elevated sites (>1.5 km; 11 sites) in Intermountain West for spring and summer 2006
1:1 line
max
min
75th
50th
25th
r = 0.57
r = 0.33
Model underestimates high extrema in spring (> 75 ppbv) - stratosphere
Correlation with measurements is poor in summer – lightning, wildfires
Lin Zhang, Harvard

11. Model underestimate of stratospheric intrusions in spring
Sample stratospheric intrusion at Pinedale (WY) : model captures timing but not magnitude.
Obs.
observations
model
PRB
stratosphere
Observed vs. simulated MDA8 ozone in spring 2006 at the 11 elevated CASTNet sites, colored by model stratospheric ozone concentration.
Model has correct STE and vertical transport; we attribute problem to the general difficulty of Eulerian models in resolving fine structures.
Lin Zhang, Harvard

12. Ozone enhancement from lightning in Intermountain West
observations
model
PRB
lightning
Model lightning increases ozone concentrations by 7-19 ppbv in summer, comparable to enhancements from US anthropogenic emissions.
This lightning influence in the model is biased high, even though lightning location is constrained by OTD/LIS satellite observations;
focus future model improvement on NOx yield per lightning flash, vertical distribution
Note the model overestimates in August.
Lin Zhang, Harvard

13. Sensitivity of model ozone to wildfire emission inventory
Maximum fire enhancements of MDA8 ozone
In GEOS-Chem – August 2006
Sensitivity of model ozone to wildfire emission inventory
fire reports
monthly
Model is highly sensitive to choice of inventory, spatial and temporal resolution
Influence of fires is mainly limited to fire region; little influence at CASTNet sites in 2006
Need to examine other years, MOPITT and AIRS CO data for fires
Lin Zhang, Harvard

14. Process-oriented analysis of multi-platform observations with a new, global high-resolution chemistry-climate model
AQAST PI Arlene Fiore (Columbia U.)
Problems:
1) Coinciding ozone maxima of stratospheric and anthropogenic origin [e.g. Stohl and Trickl 1999; Cooper et al 2004; Ambrose et al., 2011]
2) Limitations of tropospheric CTMs in capturing observed dynamic variability in ozonesondes [e.g. Jaegle et al., 2003; Liang et al., 2007; Jonson et al., 2010]
3) Prior multi-model evaluations on campaign /monthly mean basis [e.g. Dentener et al 2006; Stevenson et al., 2006; Fiore et al., 2009]
GFDL AM3
Our Approach:
1) Global high-res (50 km) with fully coupled strat+trop chemistry [Donner et al., 2011]; Nudged to GFS
2) Analyze transport events on daily basis, leveraging intensive measurements from CalNex 2010
Sondes
AQS/CASTNet

15. Trans-Pacific transport of Asian pollution plumes to WUS often coincides with O3 injected from stratosphere
from Asia
Primarily strat
1-min:
Observed
GFDL AM3
Zero Asian emissions
O3-strat
Complex mixing of Asian pollution + stratospheric air in continental inflow
How much does Asian pollution contribute to surface high-O3 events?
Lin et al., JGR, 2012 – DOWNLOAD PDF HERE

16. Tighter standard… harder to attain with domestic control
Asian pollution contribution to high surface O3 events,
confounding to attain tighter standard in WUS
Obs (CASTNet/AQS)
AM3/C180 total ozone
AM3/C180 Asian ozone
June 21
2010
June 22
2010
Max daily 8-h average
Tighter standard… harder to attain with domestic control
Lin et al., JGR, 2012

17. Transport of Asian pollution on the isentropic surfaces to the lower troposphere over the LA Basin
Asian enhancements to trop column O3 on May 8, 2010
Vertical cross-section of Asian O3 along California coast
[ppb]
1-min: θ
Previously identified isentropic transport mechanism [Brown-Steiner and Hess, 2011]
[K]
Asian ozone available to be intercepted by the elevated terrain or entrained into the daytime boundary layer (~1-4 km in depth)
Lin et al., JGR, 2012

18. The Asian enhancement increases for total O3 in the ppb range over Southern California, Arizona
1-min
Overall patter  increase
-- explain points in the green and red trapezoid
-- statistics
-- Model bias does not have a direct relationship with Asian enhancements
25th
Lin et al., JGR, 2012

19. Two models show different strengths in capturing distributions of base-case and N. American background O3
U.S. CASTNet sites
Observed
GEOS-Chem total GFDL AM3 total
GEOS-Chem NAB GFDL AM3 NAB
below 1.5 km
+ above 1.5 km
Zhang et. al.,2011
2006 MAM
intermountain west sites > 1.5 km
2006 JJA intermtn west sites > 1.5 km
0.06
0.04
0.02
0.00
0.06
0.04
0.02
0.00
Frequency per ppb
Summer (JJA); sites < 1.5 km
Frequency unit?
Surface MDA8 O3 [ppb]
GC and AM3 bracket observed distribution but switch from spring (AM3 higher; strat. O3?) to summer (GC higher; lightning NOx?)
GC narrower N American background distribution
Value in multi-model approach to inform policy
Oberman et al., in prep 19