Transcript Document 7833664

Chemical Composition of PM2.5 over N. America
Sequoia
Yellowstone
?
Big Bend
(scale 0-15 ug/m3)
?
Mammuth Cave
G.Smoky Mtn.
Aerosol Types
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Aerosol are composed of multiple types. Each type may be considered a different
pollutant since it has its own class of sources, aerosol properties and is associated
with different effects.
In other words, sulfate, nitrate organics, dust (soil) components of PM have no more
commonalities then CO, NOx and SO2.
The aerosol types are lumped into “PM2.5” by the current regulations.
The IMPROVE aerosol types are:
SULFATE
NITRATE
ORGANICS
SOOT
SOIL
FMASS
CMASS
= 4.125*S
Ammonium sulfate
= 1.29*NO3
Ammonium nitrate
= 1.4(O1+O2+O3+O4+OP)
1.4* various organics (OMC)
= E1+E2+E3+OP
Light absorbing carbon (LAC)
= 2.2AL++2.49SI+1.63CA+2.42FE+1.94TI
Crustal elements
= SULFATE + NITRATE + LAC + OCM + SOIL Reconstructed fine mass
= MT-MF
Coarse=PM10-FMASS
Issue: Each aerosol type has many variants in nature. I think that the IMPROVE typing (aggregation) used by Malm & Co is good
and it should be retained for presenting the network results. Need for alternative aggregations? I am open for discussion RBH.
Method: Cumulative Seasonal PM2.5 Composition
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PM2.5 chemical components were calculated based on
the CIRA methodology
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In addition, the the organics were (tentatively) further
separated as Primary Smoke Organics (red) and
Remainder organics (purple)
PSO = 20*(K - 0.15*Si – 0.02* Na)
Remainder Org = Organics - PSO
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Also, the ‘Unknown’ mass (white area) is the
difference between the gravimetrically measured and
the chemically reconstructed PM2.5.
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The daily chemical composition was aggregated over
the available IMPROVE data range (1988-99) to retain
the seasonal structure.
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I order to reduce the noise the daily data were
smoothed by a 15-day moving average filter.
Shenandoah
Regional Grouping of Sites
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IMPROVE sites were grouped as
follows:
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New England ()
Mid-Atlantic ()
Central EUS ()
Peripheral ()
Peripheral Sites: Chemical Mass Balance
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Eastern N. America is
surrounded by aerosol source
regions such as Sahara and
Central America.
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As a consequence, the PM
concentration at the ‘edges’
ranges between 4-15 ug/m3;
much of it originating outside.
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The chemical composition of
the inflow varies by location
and season.
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Sahara dust, and smoke from
Central America and W.
US/Canada are the main
contributions.
Badlands
(scale 0-15 ug/m3)
Big Bend
(scale 0-15 ug/m3)
Voyageurs
Acadia
(scale 0-15 ug/m3)
Everglades
Peripheral Sites
Badlands
(scale 0-15 ug/m3)
Big Bend
(scale 0-15 ug/m3)
Voyageurs
Acadia
(scale 0-15 ug/m3)
Everglades
Upper Buffalo
Sipsy
Mammuth Cave
Shining Rock
G.Smoky Mtn.
Mid-Atlantic Region
Shenandoah
Dolly Sods
Washington DC
Brigantine
Jefferson
New England Region
Proctor Maple
Lye Brook
Acadia
Moosehorn
Ringwood
Upper Midwest
Voyageurs
Badlands
TX, NM
Bandelier
Chiricahua
White River
Guadalupe
Big Bend
TX, NM
Tonto
Petrified For.
Saguaro
Chiricahua
TX, NM
Tonto
Petrified For.
Saguaro
Chiricahua
Idaho
Jawbridge
Tonto
Great Basin
Three Sisters
Yellowstone
Bridger
California - Background
Crater Lake
Lessen
Bliss State
(1980 m)
(1800 m)
(2043 m)
Point Reyes
(38 m, Beach)
California - Perturbed
Yosemite
Pinnacles
S. Lake Tahoe
Sequoia
San Gorgonio
Northwest - Perturbed
Abbotsford
Chilliwack
Puget Sound
(0 m)
(9 m)
(99 m)
Mt. Rainier
(436 m)
Columbia River
(90 m)
Remote ‘Global’ Sites
Denali
(640 m)
Mauna Loa
(3398 m)
Virgin Islands
(46 m)
Chemical Speciation of the Fine Mass
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Based on IMPROVE
See Sisler & Malm
Over the remote Eastern
US, sulfates dominate the
Fine Mass
The Southeast is also
influenced by ‘smoke’
(organics+LAC) and dust.
Over the West, organics,
nitrates and dust dominate