FASTNET Event Report: 040705July4Haze, July 6, 2004 July 4, 2004 Aerosol Pulse

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FASTNET Event Report 040705July4Haze, July 6,
2004July 4, 2004 Aerosol Pulse

• Event Summary by the FASTNET Community
• Please send PPT slides or comments to Erin
  Robinson or Rudy Husar, CAPITA
• Visit the event discussion forum

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Background

• During the US Independence day celebrations on
  July 4th, fireworks cause the emission of
  considerable smoke in most populated areas
• While it is a sort-term aerosol event, the
  fireworks smoke has a measurable impact on the
  local aerosol pattern
• Earlier analyses of IMPROVE aerosol chemistry
  data have shown that fireworks smoke has a strong
  signature, rich in potassium (Poirot, 1998)
• The FASTNET data shown here also demonstrates
  that the fireworks cause a strong short-term
  pulse of the PM2.5 concentration in most urban
  areas.
• A community analysis activity could quantify the
  magnitude, significance and relevance of this
  phenomenon.

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Previous work The July 4th Potassium Spike
(Poirot 1998)

• Potassium nitrate is a major component of all
  fireworks (provides the bang!).
• Fine particle K for all IMPROVE data (1988-1997)
  were averaged for each day of year
• The potassium spike on July 5 is 120 ng/m3
  compared to 40-60 during the year
• The corresponding IMPROVE-average daily fine mass
  did not show the spike
• The K spike is clearly something to consider (and
  perhaps screen out) in conducting any analyses
  using K data

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FASTNET Analysis AIRNOW PM25 Hourly data

• Hourly PM25 concentrations are averaged over all
  the AIRNOW sites (300)
• Late on July 4 and early July 5, the average
  PM2.5 increased from 12 to 35 ug/m3
• An aerosol pulse of the same magnitude occurred
  on July 4, 2003
• Thus, the July 4-5 smoke pulse is clearly
  discernable in the mass concentration data

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AIRNOW PM25 Maps, July 4, 5, 2004
1200
0000
0400
1600
0800
2000

• AIRNOW PM25 mass concentration shows urban
  hot-spots
• The aerosol pulse first appeared in the East and
  subsequently in the West
• See the GIF animation for the hourly pattern

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ASOS Light Scattering

• Hourly ASOS scattering is averaged over all the
  ASOS_STI sites (200)
• Conspicuous is the absence of ANY trace of the
  July 4 spike
• Note ASOS sites are at airports many AIRNOW
  sites are downtown

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Discussion Issues

• Why is the PM25 mass spike so strong in AIRNOW
  but not in the IMPROVE data?
• Is the fireworks smoke significant on regional
  scale?
• How to handle the July 4th data in the source
  apportionment models (UNMIX, PMF)
• Is the PM25 and potassium pulse useful for
  further tracer analysis?

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July 4, 2004 Aerosol Pulse

• The US-avg. AIRNOW PM25 shows a 3 hr. spike at
  midnight
• In the (airport) ASOS the July 4 spike is
  conspicuously absent
• Thus, the US spike is due to the urban sites
  affected by smoke

AIRNOW PM25
2000
AIRNOW PM25 US Hourly Average
Pulse
0000
ASOS Bext US Hourly Average
No Pulse
0400
0800