NARSTO PM Assessment Chapter 5: Spatial and Temporal Pattern TOC Introduction Data Global Pattern NAM Dust NAM Smoke NAM Haze NAM Total PM Local PM Speciated Seasonal Pattern

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NARSTO PM AssessmentChapter 5 Spatial and
Temporal PatternTOC Introduction Data Global
Pattern NAM Dust NAM Smoke NAM Haze NAM Total
PM Local PM Speciated Seasonal Pattern

• The seasonal aerosol aerosol pattern at the
  IMPROVE sites is examined using two
  methodologies
• Seasonal Mass Balance Charts
• Seasonal Percentile Frequency Charts

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Background Chemical Speciation of the Fine Mass

• From Previous Work IMPROVE
• See Sisler Malm

• Over the most of the Eastern US, sulfates
  dominate the Fine Mass
• The Southeast is also influenced by organics,
  carbon and dust.
• Over the West, organics, nitrates and dust
  dominate

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Method 1 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
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Method 2 Seasonal Percentiles, 1992-99

• The charts depict the magnitude of seasonal and
  synoptic variation
• The synoptic-scale variation (day-to-day) can be
  measured by the 20-80 percentile spread

Great Smoky Mtn.
Lye Brook
Dirty days, 80-90
Dirty days, 80-90
Clean days (20)
Clean days (20)

• At Lye Brook, VT, the clean days (20 percentile)
  corresponds to 4 ug/m3 throughout the year
• The dirty days are (80-90-ile) have 2-5 times
  higher concentration than the clean days.

At the Smoky Mtn, the clean days in the winter
are also 4 ug/m3. However in the summer, even
the clean days have 14 ug/m3 PM2.5. The dirty
days are have 2-3 times higher than the clean
days through out the year.
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Regional Grouping of Sites

• For this presentation the IMPROVE sites were
  grouped as follows
• New England ()
• Mid-Atlantic ()
• Central EUS ()
• Peripheral ()
• For each region, the seasonality is displayed
  for
• Chemical Mass Balance
• Carbonaceous Mass Balance
• Fine Particle Mass Percentiles
• Coarse Mass Percentiles
• Sulfate Percentiles
• Fine Soil Percentiles
• Tot. Carbon. 'Unknown' Percentiles
• Smoke Organics Percentiles

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New England Chemical Mass Balance
Moosehorn
Acadia
Lye Brook
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New England Carbonaceous Mass Balance
Moosehorn
Acadia
Lye Brook
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New England Fine Particle Mass Percentiles
Moosehorn
Acadia
Lye Brook

• Fine mass

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New England Coarse Mass Percentiles
Moosehorn
Acadia
Lye Brook

• Coarse mass

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New England Sulfate Percentiles
Moosehorn
Acadia
Lye Brook

• Non-sea salt sulfate

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New England Fine Soil Percentiles
Acadia
Lye Brook

• Fine Dust

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New England Tot. Carbon 'Unknown' Percentiles
Moosehorn
Acadia
Lye Brook

• Carbonaceous

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New England Smoke Organics Percentiles
Moosehorn
Acadia
Lye Brook

• Smoke organics

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Mid-Atlantic Chemical Mass Balance
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson
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Mid-Atlantic Carbonaceous Mass Balance
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson
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Mid-Atlantic Fine Particle Mass Percentiles
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson

• Fine mass

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Mid-Atlantic Coarse Mass Percentiles
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson

• Coarse mass

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Mid-Atlantic Sulfate Percentiles
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson

• Non-sea salt sulfate

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Mid-Atlantic Fine Soil Percentiles
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson

• Fine dust

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Mid-Atlantic Tot. Carbon 'Unknown' Percentiles
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson

• Carbonaceous

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Mid-Atlantic Smoke Organics Percentiles
Washington DC
Brigantine
Shenandoah
Dolly Sods
Jefferson

• Smoke organics

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Central EUS Chemical Mass Balance
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy
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Central EUS Carbonaceous Mass Balance
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy
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Central EUS Fine Particle Mass Percentiles
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy
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Central EUS Coarse Mass Percentiles
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy

• Coarse mass

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Central EUS Sulfate Percentiles
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy

• Non-sea salt sulfate

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Central EUS Fine Soil Percentiles
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy

• Fine dust

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Central EUS Tot. Carbon 'Unknown' Percentiles
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy

• Carbonaceous

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Central EUS Smoke Organics Percentiles
Upper Buffalo
Mammoth Cave
Shining Rock
G.Smoky Mtn.
Sipsy

• Smoke organics

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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
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Peripheral Sites Carbonaceous Mass Balance
Voyageurs (scale 0-15 ug/m3)
Badlands (scale 0-15 ug/m3)
Acadia (scale 0-15 ug/m3)
Big Bend (scale 0-15 ug/m3)
Everglades (scale 0-15 ug/m3)
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Peripheral Sites Fine Particle Mass Percentiles
Voyageurs
Acadia
Badlands
Big Bend
Everglades

• Fine mass

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Peripheral Sites Coarse Mass Percentiles
Voyageurs
Acadia
Badlands
Big Bend
Everglades

• Coarse mass

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Peripheral Sites Sulfate Percentiles
Voyageurs
Acadia
Badlands
Big Bend
Everglades

• Non-sea salt sulfate

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Peripheral Sites Fine Soil Percentiles
Voyageurs
Acadia
Badlands
Big Bend
Everglades

• Fine Dust

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Peripheral Sites Tot. Carbon 'Unknown'
Percentiles
Voyageurs
Acadia
Badlands
Big Bend
Everglades

• Carbonaceous

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Peripheral Sites Smoke Organics Percentiles
Voyageurs
Acadia
Badlands
Big Bend
Everglades

• Smoke organics

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Missing Fine Mass

• The gravimetric PM2.5 is generally higher than
  the reconstructed mass.
• The excess Unknown gravimetric mass is highest
  in the Eastern US.
• The Unknown mass is highest in the summer,
  reaching 3 ug/m3 near the Appalachian region.
• Coastal sites also show significant missing
  mass.
• In some areas, e.g. near the LA Basin, the
  gravimetric mass is less then the chemical mass.
• This tends to coincide with significant amount of
  aerosol nitrate. Indication of nitrate loss from
  the gravimetric filters?