Carbonaceous Aerosol and Smoke over the Eastern US

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Carbonaceous Aerosol and Smoke over the Eastern
US

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Objectives and Approach to the Analysis

• Background
• There is considerable evidence that smoke from
  biomass fires constitutes a significant component
  of the aerosol over North America, particularly
  in the PM2.5 size range.
• However, both the recent and previous research
  results on smoke are fragmented, and uneven in
  spatial, temporal an compositional coverage.
• An integrated assessment of the North American
  smoke using the rich literature and the most
  recent data would be most desirable.
• Objectives
• Explore qualitatively the spatio-temporal and
  chemical pattern of smoke over North America
• Characterize spatio-temporal features of smoke
  dust from the different sources
• Approach
• Integrate data from surface and satellite
  observations
• Combine spatial, temporal and compositional
  analysis
• Invite the community to actively particulate in
  conducting this open, integrative analysis
• Status (May 2001)
• Recent data from several satellite and surface
  sensors were analyzed and presented graphically
• The data and knowledge from the literature has
  not yet been incorporated
• An open discussion and interaction with the
  community is to begin in June 2001

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Applications of this Work

• NARSTO-PM Assessment. NARSTO is conducting a PM
  Assessment for North America. This work supports
  the NARSTO PM Assessment process.
• Monitoring Network Design/Evaluation. EPA is
  implementing an extensive monitoring network for
  speciated PM sampling. This work supports the
  design and performance-evaluation of the new
  network.
• MODELS-3 Evaluation. EPAs MODELS-3/CMAQ is a
  sophisticated high resolution, regional-scale
  modeling system designed to simulate and
  investigate gaseous and fine pattern over the US.
  This work supports the evaluation and further
  development of the model.
• Regional Haze Management. In response to the new
  haze regulations, Regional Planning Organizations
  (RPOs, Central States, Northeast OTC, Western
  States ) have been set up for haze management.
  This work is to provide background information to
  be used by the RPOs.

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Smoke Physical, Chemical and Optical Properties

• Physical - size distribution and shape
• Determines the atmospheric residence time,
  optical properties
• Chemical elemental and molecular composition
• Influences optical properties and other effects
  on health
• Serves as source fingerprint
• Optical refractive index
• Influences effects on visibility and climate
• Allows detection by remote sensing

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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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Central EUS Chemical Mass Balance
Upper Buffalo
Mammoth Cave
Shining Rock

• The pattern of the Central EUS is similar to the
  Mid-Atlantic region
• However, several stations show multiple peaks

G.Smoky Mtn.
Sipsy
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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.
• At the Everglades, organics, smoke organics and
  LAC dominate over sulfate and fine dust
• Sahara dust, and smoke from Central America and
  W. US/Canada are the main contributions to
  Everglades, FL, and Big Bend, TX.

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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Central EUS Carbonaceous Mass Balance
Upper Buffalo
Mammoth Cave
Shining Rock

• Throughout the Central EUS, the carbonaceous
  aerosol contributes 4-6 mg/m3
• There is a 50 seasonal variation with a summer
  peak
• Smoke Organics constitute 20-30 of the total
  organics

G.Smoky Mtn.
Sipsy
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Peripheral Sites Carbonaceous Mass Balance

• At the northern peripheral sites, Badlands,
  Voyageurs and Acadia, the organics range from 1.5
  to 4 mg/m3
• At Big Bend the organics show a spring peak, with
  a majority of smoke organics. This indicates
  biomass smoke origin.
• At the Everglades, the fall peak is due to
  organics, while smoke organics light absorption
  is present throughout the year.

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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Smoke from Central American Fires

• Fire locations detected by the Defense
  Meteorological Satellite Program (DMSP) sensor.
• The sensor detects low levels of visible night
  at night

May 15, 98

• Satellite image of color SeaWiFS data, contours
  of TOMS satellite data (green) and surface
  extinction coefficient, Bext
• The smoke plume extends from Guatemala to Hudson
  May in Canada
• The Bext values indicate that the smoke is
  present at the surface

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St. Louis Atlanta, Dec 1998

• During the fall season, fires and biomass smoke
  can be observed throughout the southeastern US.
• During a St. Louis Atlanta flight, December
  1998 over a dozen biomass smoke plumes were
  photographed (right).
• Satellites now allow detection of fire locations
  through out the world.
• For example, in December 1998, the fires recorded
  by the ESA IONIA Program are indicated below

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Astronaut Photos

• On a single day, an astronaut photo of North
  Carolina reveals over a dozen individual smoke
  plumes. These are presumed to be biomass fires.

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Smoke Plumes over the Southeast
R 0.68 mm G 0.55 mm B 0.41 mm

• Satellite detection yields the origin and
  location is the shape of smoke plumes

0.41 mm

• The influence of the smoke is to increase the
  reflectance ant short wavelength (0.4 mm)
• At longer wavelength, the aerosol reflectance is
  insignificant.

0.87 mm
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Smoke Aerosol and Ozone During the Smoke Episode
Inverse Relationship
Extinction Coefficient (visibility)
Surface Ozone
The surface ozone is generally depressed under
the smoke cloud
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Hourly PM10 During the Smoke Event
Hourly PM10 concentration pattern at six eastern
US locations during May 1998.
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Smoke Composition at Big Bend, TX
Daily average light scattering coefficient and
chemically speciated fine mass concentration for
the IMPROVE monitoring site at Big Bend, TX, May
1998.
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Central American Smoke Pattern, April, 2000

• The May major 1998 Central American smoke event
  was not a unique phenomenon. On April 25, 2000,
  the intense smoke plume was similar to the 98
  event. The plume covers part of Florida.

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