update on improve light extinction equation and natural conditions estimates tom moore, wrap...
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![Page 1: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/1.jpg)
Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates
Tom Moore, WRAP Technical Coordinator
May 23, 2006
![Page 2: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/2.jpg)
OR …….
Defining Regional Haze Impacts with Aerosol Sampling Data
AND …….
Knowing the unknowable
![Page 3: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/3.jpg)
“Old” IMPROVE Light Extinction Equation• Developed in late 1980’s – consensus light extinction
coefficients for species measured by IMPROVE aerosol sampler
• Adopted by EPA for “Tracking Progress” – regional haze monitoring guidance documents are at: http://vista.cira.colostate.edu/improve/Publications/GuidanceDocs/guidancedocs.htm
• Equation is used to estimate light scattering by particles:
10
6.0
1
10
4
)(3
)(3
MassCoarse
SoilFine
CarbonElemental
MassOrganic
NitrateRHf
SulfateRHfbext
![Page 4: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/4.jpg)
“Revised” IMPROVE Light Extinction Equation
• Review process by IMPROVE Steering Committee and scientific community during 2005
• Findings of review prepared by Jenny Hand & Bill Malm presented and discussed at: http://www.wrapair.org/forums/aamrf/meetings/050608den/index.html
• Technical document describing revised equation: http://vista.cira.colostate.edu/improve/Publications/GrayLit/019_RevisedIMPROVEeq/RevisedIMPROVEAlgorithm3.doc
• Light extinction data from 2000 onward are calculated and available using old and revised equation on VIEWS: http://vista.cira.colostate.edu/views/ and the WRAP TSS: http://vista.cira.colostate.edu/tss/
![Page 5: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/5.jpg)
“Revised” IMPROVE Light Extinction Equation
ppb)(NO0.33
Specific)iteS(ScatteringRayleigh
SaltSeaRH)(f1.7
MassOrganicargeL6.1MassOrganicSmall2.8
NitrateargeLRH)(f5.1NitrateSmallRH)(f2.4
SulfateargeLRH)(f4.8SulfateSmallRH)(f2.2
2
SS
LS
LS
MassCoarse
SoilFine
CarbonElemental
bext
6.0
1
10
Bottom line:
• New equation fitted to aerosol data collected 2000-04 using light extinction coefficients from research literature, to better match observed optical light scattering data
• Corrects bias but increases scatter at some sites
![Page 6: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/6.jpg)
Light Extinction using old and revised IMPROVE Equation
0
50
100
150
200
250
300
350
0 50 100 150 200 250 300 350
Measured Bsp
IMPR
OVE
Bsp
Scatter plot of the old IMPROVE equation estimatedparticle light scattering versus measured particle light
scattering.
0
50
100
150
200
250
300
350
0 50 100 150 200 250 300 350
Measured Bsp
Split
Com
pone
nt M
etho
d B
sp
Scatter plot of the revised IMPROVE equation estimatedparticle light scattering versus measured particle light
scattering.
![Page 7: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/7.jpg)
Natural Conditions Estimates
• NAPAP Visibility Report (Volume 24) [1990] authored by Trijonis, et. al.
• Based on available IMPROVE network data and other data sources
• Estimated contiguous East and West U.S. annual average natural mass loading for visibility-impairing aerosols [specified uncertainty by species]
• [Well] Known to underestimate natural carbon
• Adopted by EPA for “Estimating Natural Visibility Conditions” using “old” equation – regional haze monitoring guidance documents are at: http://vista.cira.colostate.edu/improve/Publications/GuidanceDocs/guidancedocs.htm
• Default Natural Haze Levels Sensitivity Assessment project for the 5 RPOs
• Ivar Tombach is doing the analysis
• Initial findings were presented at a June 2005 workshop http://www.wrapair.org/forums/aamrf/meetings/050608den/index.html
• Final report soon?
![Page 8: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/8.jpg)
“Default” Natural Conditions Estimates20% Best Days (left) & 20% Worst Days (right)
![Page 9: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/9.jpg)
What should be done [if anything] with “default” Natural Conditions Estimates?
• Knowing the unknowable – April 4, 2006 – Inter-RPO Monitoring and Data Discussion Group analysis presentation on revised natural condition estimates using the new IMPROVE algorithm and a revised statistical approach – Ames & Pitchford
• Things to think about:– Natural conditions vary continuously in space and time – do any historic data inform
better estimates for planning purposes?– The worst and best visibility days’ default natural conditions estimates are projected
from measured distributions of aerosol data – these are for total light extinction in DECIVIEWS, not for individual species – how does that line up for the WRAP region?
– How often will we see frequent large OC/EC and Dust events over the next 50 to 60 years?
– Do we need to apply the revised IMPROVE equation to natural conditions estimates?– What monitoring period of record can be used to estimate natural conditions?– Can we make a better estimate of the distributions of worst and best visibility days 58
years out, than John Trijonis did?– What are the planning implications of adjusting natural conditions estimates up and/or
down and changing the glide path for 116 Class I areas in the WRAP region, either for deciviews or individual species?
– Where does take us for “demonstrating” reasonable progress in 2018?– More questions yet to asked -
![Page 10: Update on IMPROVE Light Extinction Equation and Natural Conditions Estimates Tom Moore, WRAP Technical Coordinator May 23, 2006](https://reader035.vdocuments.us/reader035/viewer/2022081603/56649ed15503460f94bdfd20/html5/thumbnails/10.jpg)
Next Steps on Natural Conditions Estimates in the WRAP Region
• Attribution of Haze workgroup conference call June 7th to review monitoring data issues: http://www.wrapair.org/cal/calendar.php?op=view&id=552
• Plan to have AoH workgroup recommend WRAP region approach
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http://vista.cira.colostate.edu/tss/