MAPPING OF URBAN AEROSOLS

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MAPPING OF URBAN AEROSOLS

• NEW YORK CITY AREA

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AEROSOL MAPPING TEAM

• TEAM
• Kevin Finnerty DeWitt Clinton HS
• Bob Gandolfo Plainedge HS
• Monica Coronado CCNY
• Rosenelly Perez DeWitt Clinton HS
• Jonelle Thorpe DeWitt Clinton HS

• With a lot of help from. . .
• Colley Baldwin Medgar Evers
• Brian Cairns GISS
• Jacek Chowdhary GISS
• Barry Gross CCNY
• Beate Liepert Lamont Doherty
• Fred Moshary CCNY

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RESEARCH GOALS

• LOOKING AT SPATIAL VARIABILITY OF AEROSOLS IN A
  GEOGRAPHIC AREA
• ARE SUNPHOTOMETERS IN AN URBAN ENVIRONMENT
  SIGNIFICANTLY AFFECTED BY LOCAL SOURCES
• DOES WEATHER IMPACT AEROSOL DISTRIBUTION AND
  AMOUNT

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MultiFilter Rotating Shadow band Radiometer

• Wavelengths
• 413.4 nm
• 496.6 nm
• 614.7 nm
• 672.2 nm
• 869.7 nm
• 940.7 nm

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(No Transcript)
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Sites

• City College
• Nasa Giss
• Lamont
• Medger Evers

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AEROSOL OPTICAL DEPTH

• I IO e -?/COS?
• IO INTENSITY AT TOP OF ATMOSPHERE
• I INTENSITY AT SURFACE
• 1/COS? AIR MASS
• (? cal from time/ lattitde)
• ? OPTICAL DEPTH

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Langley Regression

• IIoe-m tau
• ln I ln Io m (tau)
• Slope tau optical depth

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AEROSOL OPTICAL DEPTH ?AEROSOL (AOD)

• TOTAL OPTICAL DEPTH
• MEASURED BY SUNPHOTOMETER
• IIoe-m tau
• ?TOTAL (area)(particle density)(vertical
  extent)
• RAYLEIGH SCATTERING
• scattering of molecules ? blue sky
• ?-4
• AEROSOL OPTICAL DEPTH (AOD)
• ?AEROSOL ?TOTAL - ?RAYLEIGH (- ?OZONE -
  ?WATER VAPOR )

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METHOD OF DATA ANALYSIS

• YESDAS ROUTINE
• YANKEE ENVIRONMENTAL SYSTEMS
• VERY CONSERVATIVE
• MATLAB ROUTINE
• IN HOUSE GENERATED
• MORE FLEXIBLE ( 3 STANDARD DEVIATIONS)

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SUN INTENSITY

• NORMAL DAY
• HAZE
• CLOUD COVER

• PERFECT DAY
• NO HAZE
• NO CLOUD COVER

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YESDAS/MATLAB COMPARISON
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MATLAB CODE

• Removal of 3 SD PTS.
• -Tau is Obtainable.

• Raw Data
• -Tau is undefined.

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AEROSOL OPTICAL DEPTH - AM

• GOOD AGREEMENT ON
• CLEAR DAYS
• CLOUDY DAYS

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AEROSOL OPTICAL DEPTH - PM
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AOD vs Wavelength

• High AOD on July 9
• Analyzed for change in AOD vs Wavelength

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Windspeed and AOD
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OBSERVATIONS

• SITES VERY SIMILAR ON CLEAR DAYS
• AEROSOL OPTICAL DEPTH DOES NOT APPEAR TO BE
  DOMINATED BY LOCALIZED SOURCES
• AOD MAY TRACK WITH AIR PRESSURE/WIND
• AOD INCREASES _at_ CCNY ON CALM DAYS
• OTHER ISSUES
• LOCAL CIRCULATION
• SOURCE OF AIR MASS
• EFFECTS OF CONTRAILS OF CLOUDS
• LOCAL WEATHER

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SPECTRAL SLOPE 7/15/01 AM

• CCNY ? .86
• MEDGER ? .78
• LAMONT ? .67
• LARGER AEROSOLS

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SPECTRAL SLOPE 7/16/01 AM

• CCNY ? .98
• MEDGER ? 1.47
• LAMONT ? .82
• SMALL AEROSOLS

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CONCLUSIONS

• AOD TRACKS FOR ALL SITES
• ALL INCREASE /DECREASE
• PARTICLE SIZE VARIATION FROM DAY TO DAY
• AOD TRACKS WITH AIR PRESSURE
• AOD INCREASES _at_ CCNY ON CALM DAYS
• LIMITED DATA SET
• ONLY A FEW GOOD DAYS
• WOULD LIKE MORE WIDELY SEPARATED SITES

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FUTURE WORK

• INCLUDE SITES FURTHER FROM NYC
• ALBANY
• GLENN FALLS
• BROOKHAVEN NATIONAL LAB
• INCLUDE MORE DETAILED WEATHER ANALYSIS
• USE A LARGER DATA SET
• WEEKS/ MONTHS
• FALL / SPRING
• INCLUDE DATA ON SINGLE SCATTERING ALBEDO OR
  AMOUNT OF SOOT
• ? URBAN ORIGIN