Chemical Composition of PM2.5 over N. America

1
Chemical Composition of PM2.5 over N. America
Sequoia
Yellowstone
Mammuth Cave
?
G.Smoky Mtn.
Big Bend (scale 0-15 ug/m3)
?

2
Aerosol Types

• 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 4.125S Ammonium sulfate
• NITRATE 1.29NO3 Ammonium nitrate
• ORGANICS 1.4(O1O2O3O4OP) 1.4 various
  organics (OMC)
• SOOT E1E2E3OP Light absorbing carbon (LAC)
• SOIL 2.2AL2.49SI1.63CA2.42FE1.94TI
  Crustal elements
• FMASS SULFATE NITRATE LAC OCM
  SOIL Reconstructed fine mass
• CMASS MT-MF CoarsePM10-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.

3
Method Cumulative Seasonal PM2.5 Composition

• PM2.5 chemical components were calculated based
  on the CIRA methodology
• In addition, the the organics were (tentatively)
  further separated as Primary Smoke Organics (red)
  and Remainder organics (purple)
• PSO 20(K - 0.15Si 0.02 Na)
• Remainder Org Organics - PSO
• Also, the Unknown mass (white area) is the
  difference between the gravimetrically measured
  and the chemically reconstructed PM2.5.
• The daily chemical composition was aggregated
  over the available IMPROVE data range (1988-99)
  to retain the seasonal structure.
• I order to reduce the noise the daily data were
  smoothed by a 15-day moving average filter.

Shenandoah
4
Regional Grouping of Sites

• IMPROVE sites were grouped as follows
• New England ()
• Mid-Atlantic ()
• Central EUS ()
• Peripheral ()

5
Peripheral Sites Chemical Mass Balance

• Eastern N. America is surrounded by aerosol
  source regions such as Sahara and Central
  America.
• As a consequence, the PM concentration at the
  edges ranges between 4-15 ug/m3 much of it
  originating outside.
• The chemical composition of the inflow varies by
  location and season.
• Sahara dust, and smoke from Central America and
  W. US/Canada are the main contributions.

Voyageurs (scale 0-15 ug/m3)
Acadia
Badlands (scale 0-15 ug/m3)
Big Bend (scale 0-15 ug/m3)
Everglades
6
Peripheral Sites
Voyageurs (scale 0-15 ug/m3)
Acadia
Badlands (scale 0-15 ug/m3)
Big Bend (scale 0-15 ug/m3)
Everglades
7
Upper Buffalo
Mammuth Cave
Shining Rock
G.Smoky Mtn.
Sipsy
8
Mid-Atlantic Region
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson
9
New England Region
Moosehorn
Acadia
Proctor Maple
Ringwood
Lye Brook
10
Upper Midwest
Voyageurs
Badlands
11
TX, NM
White River
Guadalupe
Bandelier
Chiricahua
Big Bend
12
TX, NM
Petrified For.
Saguaro
Tonto
Chiricahua
13
TX, NM
Petrified For.
Saguaro
Tonto
Chiricahua
14
Idaho
Three Sisters
Yellowstone
Tonto
Jawbridge
Bridger
Great Basin
15
California - Background
Lessen (1800 m)
Bliss State (2043 m)
Crater Lake (1980 m)
Point Reyes (38 m, Beach)
16
California - Perturbed
S. Lake Tahoe
Sequoia
Yosemite
San Gorgonio
Pinnacles
17
Northwest - Perturbed
Abbotsford (0 m)
Chilliwack (9 m)
Puget Sound (99 m)
Columbia River (90 m)
Mt. Rainier (436 m)
18
Remote Global Sites
Denali (640 m)
Virgin Islands (46 m)
Mauna Loa (3398 m)
19
Chemical Speciation of the Fine Mass

• Based on IMPROVE
• See Sisler Malm

• Over the remote Eastern US, sulfates dominate the
  Fine Mass
• The Southeast is also influenced by smoke
  (organicsLAC) and dust.
• Over the West, organics, nitrates and dust
  dominate