How dirty is our air?

What is haze (particles/particulates suspended in air)?

• What is particulate pollution? World Resources Institute site.
• What is an aerosol? (NASA Goddard definition)
• Air Info Now: How big are these particles?

Why do we care about particulates in the air?

• Why measure haze and links to other sites
• NASA on aerosols and climate
• How do aerosols link to air pollution and global warming? July 11, 2001 NASA News Alert
• Health effects of urban air pollution (World Resources Institute site)
• Interagency Monitoring of Protected Visual Environments (IMPROVE), for National Parks and Wilderness areas
• What about second-hand smoke?
  • EPA Fact Sheet: Respiratory Health Effects of Passive Smoking
  • Medline Plus links to reports
  • EPA health effects
  • World Health Organization Tobacco Free Initiative
  • California Office of Environment Health Hazard Assessment info

How do particles of various sizes scatter light?

• Learn about particulate matter types, sources, sizes, and how light is scattered by particles
• Good figures that show how particle size affects light scattering
• Why is the sky blue?
  • CoolQuiz site
  • Philip Gibbs May 1997 site
  • Weathersavvy.com site (and why sunsets are red)
  • Wisconsin site (see scattering of light)
  • RiverRoofing.com site

   

Can particles in the air come from far away?

• Recent Canadian and Alaska fires have brought haze to Minnesota (~ weekend of July 17-18, 2004)
  • NASA Dust and Smoke page (see latest events)
  • NASA Fire page (see latest events)
  • US Air Quality Smog Blog (do a search with keyword "midwest")
• NASA web page on the "natural hazards" of dust, smoke and fire and how particulate pollution spreads around the world
• Info on the Spring 2001 event that brought Asian dust storm clouds to the US. We saw this event in Minnesota!!
• Global images of aerosols (smoke and dust) from biomass burning and blowoff from desert regions in summers 1987 and 1988 in Africa and South America
• TOMS images of aerosols from biomass burning and human-made smoke
• TOMS images of aerosols from dust storms in Africa (2000) and China (1998)

What's up with the local weather?

• Carleton College weather site and weather database. Use this to help you think about how wind direction affects local sources of particles.

What's up with airborne particulates in Minnesota?

• EPA Window to My Environment. Pick a location or city and click on regulated sites, then air emissions and air monitors. If you click on number of facilities reporting to EPA in the right-hand box, you can get a list of specific emission sites.
• St. Paul Park refinery had a lightning-induced fire on Sunday July 11, 2004. Lots of black smoke and soot.
• Minnesota Pollution Control Agency (MPCA)
  • Air permits issued in Minnesota
  • Hourly Air Quality Index (AQI) in Minnesota (and links to more good stuff)
  • Air Quality Index monitoring sites in the Twin Cities (Stanton is close to Northfield)
• Environmental Protection Agency (EPA) emissions monitoring (federal agency)
  • What facilities in my area produce air emissions? (EPA Envirofacts Data Warehouse)
  • EPA air monitoring data site
• Clean Air Minnesota Fact sheets and more
• Summer 2003 special issue of Minnesota Environment Magazine on fine particulates in our air (lots of good articles!)
• Koch refinery news (mostly about their contamination of groundwater and soil)
  • MPCA info on the Koch refinery
• Midwest Haze Cam in St. Paul (live photos, along with ozone and fine particulate scales)

How are particles measured?

• TSI's hand-help Particle Condensation Counter (our primary instrument!)
  • Main page for this instrument
  • More instrument details
• NASA's TOMS Spectrometer global aerosol measurements (a satellite instrument)
  • Today's global aerosol index map
  • Aerosol index page

   

Measuring haze with "The Haze Box" (an instrument we might use)

The main haze box web site

• The main Concord web site about HAZE
• Concord web site Table of Contents

What is the haze box?

• What is a sun photometer? (the device that measures haze)
• More on sun photometer and haze box, variations on use
• Sample haze data
  • Data taken over times of the day
  • Data taken over several days

Calibrating the Haze Box

• Basics on how to calibrate the haze box
• Air mass diagram about how the sun's angle and time of day affect the measurement
• Ways to measure the sun's angle and find "local time"
• How to plot and analyze calibration data
• What is the extraterrestrial constant (ET) that is obtained during calibration?
• Info on the Langley calibration and plotting methods
  • Initial Langley calibration plot for all air masses, note nonlinearity
  • Calibration Langley plot prior to fitting, using only the linear data
  • Fitting the linear part of the calibration data to a line
  • How to plot calibration data to get the extraterrestrial constant (ET)
• The Haze formula to calculate aerosol optical thickness (AOT), the haze index

Teacher Resources

• GLOBE Project Homepage
• Info on GLOBE Program
• GLOBE Aerosol Protocol (download pdf file)

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