simulating diurnal changes of speciated particulate matter in atlanta, georgia using cmaq yongtao...
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Simulating diurnal changes of speciated particulate matter in Atlanta, Georgia using
CMAQ
Yongtao Hu, Jaemeen Baek, Bo Yan, Rodney Weber,
Sangil Lee, Evan Cobb, Amy Sullivan, Armistead G. Russell
School of Civil and Environmental Engineering and School of Earth and Atmospheric Sciences, Georgia Institute of Technology
CMAS conference, October 18th, 2006
Acknowledgements: Eric S. Edgerton and John JansenARA and Southern Company
Background
Speciated particulate matter monitored at two sites in Georgia Tech's campus, 500m away from each other
Measurements at neighboring sites HYW and ROF
• Frequency: twice per day of 12-hr average compositions of PM2.5 for daytime (10am~10pm) and nighttime (10pm~10am).
• Items: ions, EC/OC, organic compounds and metals.
• Periods: Jun. 15~18, 2006 and Jan. 19~26, 2006.
0
5
10
15
20
25
ug
/m3
NH4
SO4
NO3
EC
OC
• Findings: Compare two sites: ROF is cleaner;
SO4 and NH4: no significant difference; NO3: ROF is higher, but both very low; EC and OC: HYW is significantly higher.
Compare day and night: Higher
percentage of OC at night; Higher percentage of SO4 during day.
Other PM2.5 composition monitors in Atlanta Met
1.3-km Grid
- 56 km -
- 56 km-
• SEARCH stations: JST and YRK, hourly composition of PM2.5, as well as daily 24-hr averages
• ASACA stations: FTM, TUC, SDK, YGP, daily 24-hr average composition of PM2.5
• STN site: South De Kalb (same location as SDK), every third day 24-hr average composition of PM2.5
Super Site Jefferson Street
0
10
20
30
40
50
60
Time EST
PM
2.5
ug/m
3
Sampling frequency
STN site 130890002 South De Kalb
0
10
20
30
40
50
60
Time EST
PM
2.5
ug/m
3
Can CMAQ capture the observed gradient of the EC/OC concentration at the two closely neighboring sites?
Can CMAQ capture the observed diurnal changes of PM2.5 and its components?
Questions:
Objectives of this work
• Simulating PM2.5 speciation using CMAQ at very fine scale.
• Characterize emissions from freeway.
• Compare fine scale CMAQ results to observations using detailed speciation of organics and metals (just have EC/OC and ions for now). Next to freeway, nearby (500m), 2km away, within the region.
• Mutual calibration with receptor modeling results.
• Reconcile differences: Improve emission characterization, emissions distributions, dispersion, etc.
CMAQ v4.5 simulation • Four nesting domains down to 1.3-km resolution.
• Thirteen vertical layers, first layer ~18 meters.
• Simulating summer episode currently: June 12-20, 2005.
• SAPRC99 mechanism plus aero4 module.
• MM5 and SMOKE provide meteorology and emission rate fields.
• OSU land surface model plus 4DDA (only for 36-km and 12-km grids) used in MM5.
• VISTAS 2002 emissions inventory projected to 2005, CEM data used for EGU sources.
Brute force sensitivity simulations
sensitivity fields = air quality fields basecase - air quality fields reduced case
Domainwide 100% reduction NOx VOC SO2 NH3 EC OC EGU X X non-EGU X X mobile X X X X X non-road X X X X biogenic X biomass burning X X livestock X fugitive dust X other area sources X X
20 sensitivity runs
Modeling Domains
36-km
1.3-km
4-km
12-km
Basecase 1.3-km Grid Emissions
NOx
POAPEC
CO
Simulated Spatial Distributions on 1.3-km Grid (basecase)
O3
ECOCNO3
NH4SO4
First Concern:
Is 1.3-km grid performance worse than coarse grid?
Surface Wind Speed Surface Wind Direction Surface Air Temperature Surface Humidity Grid Bias
(m s-1) RMSE (m s-1)
Bias (deg.)
Gross Error (deg.)
Bias (K)
RMSE (K)
Bias (g kg-1)
Gross Error (g kg-1)
12-km 0.63 1.83 2.64 30.67 0.03 2.58 -1.05 1.49 4-km 0.98 1.61 3.26 34.40 0.27 2.39 -0.77 1.33 1.3-km 0.24 1.60 5.32 34.71 0.41 2.27 -0.46 1.21
MM5 Performance: 1.3-km grid vs. other resolutions
Compare with TDL hourly surface observations
Grid Species Uni t Pai rs# MOC MNB MNE FB FE O3 ppmv 46337 0.0526 -9.62 22.27 -15.50 26.35
8hrO3 ppmv 41687 0.0508 -10.36 19.55 -14.61 22.61 PM25 ug/m3 1835 10.8419 17.18 49.80 -1.05 40.69
36-km
PM25h ug/m3 40040 12.3868 34.99 91.37 -19.23 61.75 O3 ppmv 9362 0.0560 -8.00 17.18 -11.07 19.27
8hrO3 ppmv 8922 0.0537 -7.33 14.58 -9.36 15.95 PM25 ug/m3 272 16.0681 -33.36 39.15 -46.20 49.11
12-km
PM25h ug/m3 6321 17.0702 -21.76 59.59 -51.82 63.55 O3 ppmv 2227 0.0585 -13.89 18.45 -17.43 21.60 8hrO3 ppmv 2183 0.0555 -12.88 16.08 -15.25 18.22 PM25 ug/m3 65 19.1095 -45.26 48.29 -64.22 66.25
4-km
PM25h ug/m3 2114 19.4284 -36.40 54.70 -63.53 71.41 O3 ppmv 475 0.0623 -12.58 16.82 -15.40 19.36
8hrO3 ppmv 486 0.0584 -10.85 15.11 -12.86 16.83 PM25 ug/m3 26 17.7108 -45.74 46.23 -63.66 64.14
1.3-km
PM25h ug/m3 711 18.7498 -37.23 61.12 -69.81 76.95
Compare with Network measurements from: AIRNOW, STN, CASTNet (O3 only), IMPROVE, SEARCH and ASACA
CMAQ Performance: 1.3-km grid vs. other resolution
Further Concern:
Is PM2.5 performance becoming worse when compared to measurements in higher
temporal resolution?
1.3-km grid PM2.5 performanceCompare with 24-, 12- and 1-hr measurements, respectively
Species Unit Pairs# MOC MNB MNE FB FE PM25-24hr ug/m3 26 17.7108 -45.74 46.23 -63.66 64.14 PSO4-24hr ug/m3 22 4.2197 2.09 51.28 -13.93 49.88 PNO3-24hr ug/m3 22 0.2953 -80.42 80.42 -141.61 141.61 PNH4-24hr ug/m3 22 1.3740 -9.46 31.40 -16.86 33.91 PEC-24hr ug/m3 22 0.8247 60.05 102.80 5.32 62.42 POC-24hr ug/m3 22 5.2166 -70.94 70.94 -112.30 112.30 PM25-12hr ug/m3 13 18.9408 -42.45 45.45 -59.08 61.82 PSO4-12hr ug/m3 14 4.4507 7.05 46.94 -6.74 43.02 PNO3-12hr ug/m3 14 0.7007 53.85 195.09 -109.75 156.21 PNH4-12hr ug/m3 14 1.7800 -27.93 28.08 -34.66 34.81 PEC-12hr ug/m3 14 2.5100 -46.40 55.39 -77.67 84.79 POC-12hr ug/m3 14 6.8407 -80.08 80.08 -136.56 136.56 PM25-1hr ug/m3 711 18.7498 -37.23 61.12 -69.81 76.95 PSO4h-1hr ug/m3 100 4.9546 13.14 77.54 -30.25 61.21 PNO3h-1hr ug/m3 85 0.4529 -95.12 95.12 -183.09 183.09 PNH4h-1hr ug/m3 87 1.6118 -20.47 32.73 -33.18 43.64 PECh-1hr ug/m3 120 1.2989 -40.38 45.89 -58.75 63.17 POCh-1hr ug/m3 119 4.7756 -71.81 71.82 -118.98 118.98
HWY
0
5
10
15
20
25
30
6/15/05 10:00 6/15/05 22:00 6/16/05 10:00 6/16/05 22:00 6/17/05 10:00 6/17/05 22:00 6/18/05 10:00
Time EST
ug/m
3PM25 OBS
PM25 SIM
PSO4 OBS
PSO4 SIM
PNH4 OBS
PNH4 SIM
PNO3 OBS
PNO3 SIM
POC OBS
POC SIM
PEC OBS
PEC SIM
ROF
0
5
10
15
20
25
30
6/15/05 10:00 6/15/05 22:00 6/16/05 10:00 6/16/05 22:00 6/17/05 10:00 6/17/05 22:00 6/18/05 10:00
Time EST
ug/m
3
PM25 OBS
PM25 SIM
PSO4 OBS
PSO4 SIM
PNH4 OBS
PNH4 SIM
PNO3 OBS
PNO3 SIM
POC OBS
POC SIM
PEC OBS
PEC SIM
Limited EC/OC gradient was captured between HYW and ROF HIGHWAY
ROOF
EC sensitivity at HYW
-20%
0%
20%
40%
60%
80%
100%
6/13/0510:00
6/13/0522:00
6/14/0510:00
6/14/0522:00
6/15/0510:00
6/15/0522:00
6/16/0510:00
6/16/0522:00
6/17/0510:00
6/17/0522:00
6/18/0510:00
6/18/0522:00
6/19/0510:00
6/19/0522:00
Time EST
PEC_OAVOCPEC_OAPOAPEC_NVOCPEC_NPOAPEC_NPECPEC_NNOXPEC_NEGUSO2PEC_NEGUNOXPEC_MVOCPEC_MPOAPEC_MPECPEC_MNOXPEC_MNH3PEC_LNH3PEC_FPOAPEC_FPECPEC_EGUSO2PEC_EGUNOXPEC_DPOAPEC_BVOC
EC sensitivity at ROF
-20%
0%
20%
40%
60%
80%
100%
6/13/0510:00
6/13/0522:00
6/14/0510:00
6/14/0522:00
6/15/0510:00
6/15/0522:00
6/16/0510:00
6/16/0522:00
6/17/0510:00
6/17/0522:00
6/18/0510:00
6/18/0522:00
6/19/0510:00
6/19/0522:00
Time at EST
PEC_OAVOCPEC_OAPOAPEC_NVOCPEC_NPOAPEC_NPECPEC_NNOXPEC_NEGUSO2PEC_NEGUNOXPEC_MVOCPEC_MPOAPEC_MPECPEC_MNOXPEC_MNH3PEC_LNH3PEC_FPOAPEC_FPECPEC_EGUSO2PEC_EGUNOXPEC_DPOAPEC_BVOC
EC Sensitivity results show a higher contribution from traffic emissions at HIWAY
HIGHWAY
ROOF
Non-road EC
Non-road EC
Mobile EC
Mobile EC
JST
0.01
0.1
1
10
100
Time EST
log u
g/m
3
PM25 OBS
PM25 SIM
PSO4 OBS
PSO4 SIM
PNH4 OBS
PNH4 SIM
PNO3 OBS
PNO3 SIM
POC OBS
POC SIM
PEC OBS
PEC SIM
YRK
0.01
0.1
1
10
100
Time EST
log u
g/m
3
PM25 OBS
PM25 SIM
PSO4 OBS
PSO4 SIM
PNH4 OBS
PNH4 SIM
PNO3 OBS
PNO3 SIM
POC OBS
POC SIM
PEC OBS
PEC SIM
Diurnal Changes: captured OK for SO4, NH4 and EC, not OK for OC
Jefferson Street (urban)
Yorkville (rural)
OC performance: diurnal change JST
0123456789
10
Time
PO
C (ug/m
3)
OBS
SIM
YRK
0
2
4
6
8
10
12
Time
PO
C (
ug
/m3)
OBS
SIM
Jefferson Street (urban)
Yorkville (rural)
OC sensitivity at JST
-20%
0%
20%
40%
60%
80%
100%
6/13/057:00
6/13/0519:00
6/14/057:00
6/14/0519:00
6/15/057:00
6/15/0519:00
6/16/057:00
6/16/0519:00
6/17/057:00
6/17/0519:00
6/18/057:00
6/18/0519:00
6/19/057:00
6/19/0519:00
6/20/057:00
Time EST
POC_OAVOCPOC_OAPOAPOC_NVOCPOC_NPOAPOC_NPECPOC_NNOXPOC_NEGUSO2POC_NEGUNOXPOC_MVOCPOC_MPOAPOC_MPECPOC_MNOXPOC_MNH3POC_LNH3POC_FPOAPOC_FPECPOC_EGUSO2POC_EGUNOXPOC_DPOAPOC_BVOC
OC sensitivity at YRK
-20%
0%
20%
40%
60%
80%
100%
6/12/0519:00
6/13/057:00
6/13/0519:00
6/14/057:00
6/14/0519:00
6/15/057:00
6/15/0519:00
6/16/057:00
6/16/0519:00
6/17/057:00
6/17/0519:00
6/18/057:00
6/18/0519:00
6/19/057:00
6/19/0519:00
6/20/057:00
Time EST
POC_OAVOCPOC_OAPOAPOC_NVOCPOC_NPOAPOC_NPECPOC_NNOXPOC_NEGUSO2POC_NEGUNOXPOC_MVOCPOC_MPOAPOC_MPECPOC_MNOXPOC_MNH3POC_LNH3POC_FPOAPOC_FPECPOC_EGUSO2POC_EGUNOXPOC_DPOAPOC_BVOC
OC Sensitivity: does it make sense?
Jefferson Street (urban)
Yorkville (rural)
BVOC
OAPOA
NPOA
MPOAFPOADPOA
OAVOC
OAVOCOAPOANPOAMPOAMNOXFPOADPOA
BVOC
ES&T ROOF
0
2
4
6
8
10
Time EST
ug
/m3
POC OBS POCPA SIM POCS SIM POCS OBS
Estimate Secondary OC from OC measurements
When EC was well reproducedAssume Pri OCobs = Pri OCsim,then, we have SOAobs = OCobs - PriOCsim
YRK
0
2
4
6
8
10
Time EST
ug
/m3
POCPA SIM POCS SIM POCS OBS POC OBS
ROOF
Yorkville
Secondary OC was not captured by CMAQ, both mechanism and precursor emissions need improvements.
Summary
• Performance of 1.3-km grid is as good as other resolutions. This is encouraging.
• Limited EC/OC gradient was captured at neighboring sites. Link-base VMT is necessary to allocate the mobile emissions more accurately.
• Utilize modeled primary OC to split SOA from observed OC. With uncertainty.
• OC diurnal change was not captured. SOA prediction needs to be improved. Problems are from both mechanism and precursor emissions.
species unit number moc mnb mne fb fe PM25-24hr ug/m3 65 19.1095 -45.26 48.29 -64.22 66.25 PSO4-24hr ug/m3 35 4.9072 -8.48 46.59 -24.14 50.45 PNO3-24hr ug/m3 35 0.3057 -64.77 91.54 -131.97 146.43 PNH4-24hr ug/m3 35 1.4988 -13.91 27.23 -20.85 31.69 PEC-24hr ug/m3 35 0.8224 53.17 99.16 1.61 66.20 POC-24hr ug/m3 35 6.2997 -68.88 68.88 -108.53 108.53 PM25-12hr ug/m3 13 18.9408 -45.12 45.12 -61.08 61.08 PSO4-12hr ug/m3 14 4.4507 -0.67 34.59 -7.68 34.40 PNO3-12hr ug/m3 14 0.7007 -1.82 142.24 -115.68 155.95 PNH4-12hr ug/m3 14 1.7800 -28.54 28.54 -34.40 34.40 PEC-12hr ug/m3 14 2.5100 -46.55 58.06 -80.65 89.47 POC-12hr ug/m3 14 6.8407 -79.42 79.42 -134.82 134.82 PM25-1hr ug/m3 2114 19.4284 -36.40 54.70 -63.53 71.41 PSO4-1hr ug/m3 229 4.8857 -2.20 58.30 -29.46 54.26 PNO3-1hr ug/m3 229 0.3549 -79.05 90.31 -156.37 162.79 PNH4-1hr ug/m3 230 1.5436 -15.27 35.99 -26.89 43.79 PEC-1hr ug/m3 288 0.9969 -38.97 47.68 -60.38 67.36 POC-1hr ug/m3 284 4.3190 -52.61 70.00 -97.37 108.89 PTC-1hr ug/m3 284 5.3101 -50.61 64.99 -89.35 99.45
4-km grid PM2.5 performanceCompare with 24-, 12- and 1-hr measurements, respectively
EC performance JST
0
1
2
3
4
5
6
7
Time
PE
C (ug/m
3)
OBS
SIM
YRK
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Time
PE
C (ug/m
3)
OBS
SIM
SO4 performance JST
0
5
10
15
20
25
30
35
40
45
Time
PS
O4
(ug
/m3)
OBS
SIM
YRK
0
2
4
6
8
10
12
14
16
Time
PS
O4 (ug/m
3)
OBS
SIM