Air Quality Applied Sciences Team (AQAST)
EARTH SCIENCE SERVING AIR QUALITY MANAGEMENT NEEDS
Earth science resources
Air Quality Management Needs
satellites
suborbital platforms
AQAST
models
AQAST
• 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
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.)
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
Scope of current AQAST projects (IPs and TTPs)
Partner agency
• 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
AQAST bimonthly newsletter
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GEOS-Chem model simulation of background ozone over the US
in support of the current ozone ISA and REA
Color scale Indicates topography (surface pressure)
0.5x0.667
2x2.5
• 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)
• 2006-2008 3-year simulation; focus on 2006 for evaluation
Zhang et al. [Atmos.Environ., 2011] – DOWNLOAD PDF HERE
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)
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
• GEOS-Chem is overall unbiased
• PRB is 4 ppb higher than in
previous GEOS-Chem versions
• Model shows little interannual
variability for 2006-2008, neither
do observations
Zhang et al. [2011]
27 ± 6
40 ± 7
57 ± 10
58 ± 9
Model “4th highest” MDA8 ozone in 2006
Annual 4th highest ozone
PRB for annual 4th highest ozone
4th highest PRB value
Background may limit or confuse ability of West to achieve a 60 ppb NAAQS;
no such issue in East
Zhang et al. [2011]
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
r = 0.57
r = 0.33
max
75th
50th
25th
min
 Model underestimates high extrema in spring (> 75 ppbv) - stratosphere
 Correlation with measurements is poor in summer – lightning, wildfires
Lin Zhang, Harvard
Model underestimate of stratospheric intrusions in spring
Obs.
observations
model
Sample stratospheric intrusion at
Pinedale (WY) : model captures
timing but not magnitude.
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
Ozone enhancement from lightning in Intermountain West
model
observations
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
Lin Zhang, Harvard
Maximum fire enhancements of MDA8 ozone
In GEOS-Chem – August 2006
Sensitivity of model ozone
to wildfire emission inventory
• 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
fire reports
monthly
Lin Zhang, Harvard
Process-oriented analysis of multi-platform
observations with a new, global high-resolution
chemistry-climate model
AQAST PI Arlene Fiore (Columbia U.)
GFDL AM3
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]
Sondes
Our Approach:
1) Global high-res (50 km) with fully coupled
strat+trop chemistry [Donner et al., 2011]; Nudged to GFS
AQS/CASTNet
2) Analyze transport events on daily basis, leveraging
intensive measurements from CalNex 2010
Trans-Pacific transport of Asian pollution plumes to WUS
often coincides with O3 injected from stratosphere
from Asia
Primarily strat
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
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
Lin et al., JGR, 2012
Tighter standard… harder to
attain with domestic control
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]
Previously identified isentropic
transport mechanism [BrownSteiner and Hess, 2011]
Lin et al., JGR, 2012
θ[K]
Asian ozone available to be intercepted by
the elevated terrain or entrained into the
daytime boundary layer (~1-4 km in depth)
The Asian enhancement increases for total O3 in the
70-80 ppb range over Southern California, Arizona
25th
Lin et al., JGR, 2012
Two models show different strengths in capturing
distributions of base-case and N. American background O3
U.S. CASTNet sites
• below 1.5 km
+ above 1.5 km
Frequency per ppb
Zhang et. al.,2011
Observed
GEOS-Chem total GFDL AM3 total
GEOS-Chem NAB GFDL AM3 NAB
2006 MAM
intermountain west sites > 1.5 km
2006 JJA intermtn west sites > 1.5 km
0.06
0.06
0.04
0.04
0.02
0.02
0.00Summer (JJA); sites < 1.5 km
20
40
60
80
0.00
0
20
40
60
80
100
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