aerosols: types dust smoke fly ash pollen cloud mist fog smog solid liquiid
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AEROSOLS: types
• Dust• Smoke• Fly ash• pollen
• Cloud• Mist• Fog• smog
• SOLID • LIQUIID
Mount manitoba, June 1991
Asian brown cloud over China
AEROSOLS: sources
• Dust• Smoke• Fly ash• pollen• plant fragments• cement• brake lining• tires• soil
chemical concentrationfactor (surface effects)
CCF = [aerosol]/[sea]
DUST SEA
AEROSOLS: sizes
• > 400 nm scatter light• < 0.01 micron coagulate• > 10 micron settle out
• Typical size: 0.1-1 micron
AEROSOLS: how to measure them
Alphabet soup:
• COH• TSP• IP• TDF• PM10
• light scattering• collecting on filters
AEROSOLS: how to measure them
Alphabet soup:
• COH• TSP• IP• TDF• PM10
Coefficient of HazeDraw 300 meters through a filtermeasure absorbance x 100>6 bad for asthmatypical samples 5-10 micron
AEROSOLS: how to measure them
Alphabet soup:
• COH• TSP• IP• TDF• PM10
Total Suspended ParticulateWeighing after filteringUnits: μg/m3
“normal” ~ 10 μg/m3
sometimes 500 μg/m3 in cities
AEROSOLS: how to measure them
Alphabet soup:
• COH• TSP• IP• TDF• PM10
Inhalable ParticulatesGenerally IP ~ 0.45 TSP
AEROSOLS: how to measure them
Alphabet soup:
• COH• TSP• IP• TDF• PM10
Total Dust Fallunits: g m-2 month-1
should be < 7 g m-2 month-1
often exceeded in industrial areas
AEROSOLS: how to measure them
Alphabet soup:
• COH• TSP• IP• TDF• PM10
Particulate matter < 10 micron
PM10 = TSP < 10 μ
50% (by mass) of a set of particles are less then 10 micron and 50% are between 10 and 20 micron.PM10 is what percentage of PM20?
[A] 0.1 %[B] 10 %[C] 16 %[D] 50 %[E] 95 %
50% (by mass) of a set of particles are 10 micron and 50% are 20 micron.All particles larger than 10 micron are filtered out. How much does the total number of particles go down? [A] by 50%[B] by less than 50%[C] by more than 50%[D] It depends on the type of particle
10% (by mass) of a set of particles are 10 micron and 50% are 20 micron.All particles larger than 10 micron are filtered out. How much does the total surface area go down? [A] by 50%[B] by less than 50%[C] by more than 50%[D] It depends on the type of particle
coagulation
Wet deposition dry deposition
150 PAHsWith 2 – 7 rings
CombustionProducts.Fly-ash vs. bottom-ash
Particulate air quality in major world cities. Values are annual PM10 means. Horizontal line is WHO air quality guideline
NASA satelite image og Nox from ships
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