Ozone Production Efficiency in the Baltimore/Washington Urban Plume
Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production
description
Transcript of Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production
![Page 1: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/1.jpg)
Nicole WigderPh.D. Candidate
University of Washington, Department of Atmospheric Sciences5 March 2013
![Page 2: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/2.jpg)
VOCs & OVOCs + NOx → O3
downwind transport
Photo by Jon Hee
• CO• CO2
• VOCs• OVOCs• NOx• PM• CH3CHO• Etc.
Why do some wildfires produce ozone while others do not?
ozone production?
![Page 3: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/3.jpg)
Normalized Enhancement Ratios allow an analysis of variability that is not influenced by fire size or dilution:
∆O3/∆CO or ∆O3/∆CO2
![Page 4: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/4.jpg)
Plume Age Mean ∆O3/∆CO (ppbv/ppbv) (# plumes)
Range of ∆O3/∆CO
≤ 1-2 days 0.018 (n=55) -0.032-0.34
2-5 days 0.15 (n=39) -0.07-0.66
≥ 5 days 0.22 (n=29) -0.42-0.93
Boreal/ Temperate
Plume Age Mean ∆O3/∆CO (ppbv/ppbv) (# plumes)
Range of ∆O3/∆CO
≤ 1-2 days 0.14 (n=59) -0.06-0.37
2-5 days 0.35 (n=13) 0.26-0.42
≥ 5 days 0.63 (n=18) 0.19-0.87
Tropics/ Subtropics
Jaffe & Wigder (2012)
![Page 5: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/5.jpg)
VOCs & OVOCs + NOx O3
Photo credits: NPS, USFS
• Fuel nitrogen content: 0.2 - 4%• Combustion efficiency (smoldering ↔ flaming)• Photochemistry
sunlight
NOx/CO2 emission factors4.8x10-4 – 2.3x10-3 g g-1
Variation by a factor of 5!
![Page 6: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/6.jpg)
NOx
Aerosol NO3-
HNO3
PAN: temperature dependent reservoir
Within hours: ~40% of NOx → PAN (boreal; Alvarado et al., 2010)~22% of NOx → PAN (temperate; Akagi et al., 2012)
O3
![Page 7: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/7.jpg)
MBO: research site in central Oregon since 2004
2763 meters a.s.l.
Meteorological parameters, CO, PM1, O3, mercury
2012 fire season: CO2, NOx, NOy, EC/OC
![Page 8: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/8.jpg)
• multiple chemical & PM measurements
• HYPSLIT backward airmass trajectories
• MODIS near real-time images
• FIRMS fire hotspots (NASA)
COPM
1
O3
![Page 9: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/9.jpg)
r = 0.65
r = 0.14
Two fire plumes observed at MBO in 2012:
![Page 10: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/10.jpg)
32 wildfires
13 produced ozone
Wigder et al., submitted to Atmos. Environ.
These 13 fires:
∆O3/∆CO range: 0.01-0.51
Large variation within a small geographic area
MBO
![Page 11: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/11.jpg)
Wildfire plumes transported < 1 day:
∆O3/∆CO wildfire plumes
∆O3/∆CO wildfire/urban mixed plumes
0.04 (n=2) 0.28 (n=2)
That’s a factor of 7 increase in mixed plumes!
Similar results for Californian plumes (Singh et al., 2012)
![Page 12: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/12.jpg)
MBO
fire
![Page 13: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/13.jpg)
![Page 14: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/14.jpg)
flaming
smoldering
![Page 15: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/15.jpg)
975 µg/m3
Photo by Jon Hee
![Page 16: Ozone Production from Wildfires in the West Part 1: Factors Influencing Ozone Production](https://reader036.fdocuments.us/reader036/viewer/2022081516/568144db550346895db1a749/html5/thumbnails/16.jpg)
Wildfire identification easiest using a combination of multiple chemical measurements, satellite data and models
Ozone enhancements not necessarily related to PM enhancements
Large variability in ozone production, even within one biome
Evidence that ozone production affected by:• Combustion efficiency• PM• Transport distance• PAN