modeling the contribution of wildfire emissions to ambient...
TRANSCRIPT
Modeling the Contribution of
Wildfire Emissions to
Ambient PM2.5 & Black Carbon
Serena Chung1, Rodrigo Gonzalez-Abraham 2
Farren Herron-Thorpe3,
Brian Lamb1, Sim Larkin4, Tara Strand 5
1Laboratory for Atmospheric Research, Washington State University
2Molina Center for Strategic Studies in Energy and Environment 3Washington Department of Ecology
4U.S. Forest Service Pacific Northwest Research Station 5Scion Research
NW-AIRQUEST Annual Meeting
June 19, 2014
Introduction
• Funded by the Joint Fire Sciences Program
• Objectives:
– Quantify the contributions for fires to ambient
• BC
• PM2.5
– Evaluate inter-annaul variability
• Approach:
– Modeling: WRF-BlueSky-CMAQ Modeling
• 36-km CONUS, Jun-Jul-Aug, 1996-2005
– Observations: IMPROVE Network
2
Modeling Framework
3
SMOKE
CMAQ
MEGAN
WRF
BlueSky “pthour” method w/ WRAP plume-
rise
Large-Scale Reanalysis
Meteotrology
3D Hourly Meteorology
Historical Fire Database
Hourly Fire Emissions &
With Plume Rise
Biogenic Emissions
NEI 2002 Anthropogenic
Emissions
3D Hourly Speciated Emissions
3D Hourly BC, OC, PM2.5, etc Concentrations
BlueSky Framework Options
4
Fuels
Total
Consumption
Time
Rate
Emissions
Plume
Rise
FCCS
NFDRS
Hardy
Manual CONSUME
FEPS
EPM
FOFEM
Manual
FEPS
EPM
WRAP
FOFEM
Manual
FEPS
FOFEM
CONSUME
Manual WRAP
FEPS
Manual
Dispersion
CALPUFF
HYSPLIT
Area Burned & Modeled PM2.5 Emissions
5
Monthly
PM2.5 Emission (Gg)
from BlueSky
(16% and 77% of PM2.5
emissions were assumed to be
BC and organic aerosol,
respectively.)
Monthly
Acres-Days Burned x 10-6
(http://capita.wustl.edu/fsan/FedFireHist.htm)
Fire Emissions: August of 1997-2005
6
August-Total Fire BC Emissions
Averaged over 1997-2005
August-Total Fire BC Emissions
Maximum during 1997-2005
Modeled BC Concentrations: August of 1997-2005
7
August-Mean BC Concentrations
from Fires
Averaged over 1997-2005
August-Mean BC Concentrations
from Fires
Maximum during 1997-2005
8
1
2
3 4
5 6 Modeled vs Observed BC Concentrations
August of 1997-2005
9
1
2
3 4
5 6 Modeled vs Observed PM2.5 Concentrations
August of 1997-2005
Modeled vs Observed BC Concentrations
August of 1997-2005
10
1
2
3 4
5 6
Modeled vs Observed PM2.5 Concentrations
August of 1997-2005
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1
2
3 4
5 6
August 2000 Results
12
Fire BC Emission
(total for the month)
Fire Contribution to
BC Concentration
(averaged over the month)
Modelel vs Observed BC & PM2.5 for August 2000
13
Fire Contribution to
BC Concentration
(averaged over the month)
Modelel vs Observed BC & PM2.5 for August 2000
14
Modeled vs Observed BC Concentrations:
August of 1997-2005
15
1
2
3 4
5 6
Modeled vs Observed PM2.5 Concentrations:
August of 1997-2005
16
1
2
3 4
5 6
Summary
17
• For the August 2000 high fire season in central Idaho and western Montana
– On average, model predictions for BC agree well with IMPROVE data
– The model tends to underpredict PM2.5
– The model sometimes over predicts BC and PM2.5 ”close” to the fires, but
under predicts further downwind.
• Possibly because too much smoldering emissions are trapped in the first model in the BlueSky’s “pthour” method.
– Modeled BC to PM2.5 ratios tend to be higher than observed
• 16% and 77% of fire PM2.5 emissions were assumed to be BC and organic aerosol, respectively
• For other periods, the model tends to underpredict predict both PM2.5 and BC
• Insufficient secondary organic aerosol (SOA) formation could explain some of the underprediction
Modeled vs Observed BC Concentrations
August of 1997-2005
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1
2
3 4
5 6