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Air: August 12

Goal for day 1: Complete satellite analysis section of the chapter

Location: H114, back

Session 1: 10:00 - 12:00

  • Go over data sheets; finalize data sheets
  • Outline procedure for accessing data using NEO and/or Giovanni
12:00 – 1:00 Lunch

Session 2: 1:00 – 3:00

  • Decide on science question for the satellite analysis
  • Identify background information and, if applicable, related questions that could be addressed with data

Ground measurement ideas:

AERONET, use existing data

Pyronometer, David Brooks has instructions on how to build

Sun photometer: expense $120

Metadata: cloud cover, sky color,

Tracking form, over a couple of weeks and compare to real data. Correlate between visual observations

Visibility: point of reference to see how far you can see

Is data broad enough spatially to accommodate everyone?

Aerosol events are regional; modis does well in identifying it; there are gaps in satellite data

PM 2.5 EPA monitors widely distributed enough that people can use it as a point of reference

Submodel grid of aerosol optical depth; can citizen science measurements feed into this?

Sun photometer can only be used when you can see the sun.

Sun photometer picks up AOD well; difficult to do alone, need a team;

What is satellite activity?

Pick places to monitor with satellite? Correlate local to satellite in region and globally

Look at events? Submit to the Earth Observatory. Site, have people load image of where they are. People upload their photos?

Sunphotometer data sharing?

Aeronet. AOT and Google maps? Spatial distribution of data?

Integrate measurements, help people look at things together

AOD and true color? OMI aerosol index?

Need True color data sheet

1:00 – 3:00 Breakout session:
  • Decide on science question for the satellite analysis
  • Identify related questions that could be addressed with data
Tools/data sources:
MODIS aerosol optical depth (NEO/GIOVANNI/IDEA)
MODIS True color: NEO/Rapid Response/IDEA
Smog Blog
Aeronet data (data synergy tool/data display)

How dirty is my air?
Why does my air look dirty?
Why can't I see very far?
How far can I see?
What color is the air?
We have to breathe *that*?

Case study: relation of visibility to EPA air quality index and how the AQI is affected by ozone

Level I - subjective observation

1. Observe the sky. Select a prominent landmark and determine the visibility using the guidelines (AU guides). You may also use a camera to record each event for more accurate determination over time. Note: Ensure that your camera settings (iso, exposure, etc) are the same. Setting your camera to 'auto' will not guarantee that the settings are the same.
Leverage picture post? put up a few common picture posts in community

2. Record the following data:
* location (use Google Earth to determine your latitude and longitude and distance from your location to the landmark)
* Your general observations about weather and sky conditions during the observation. Are there events (fire, high traffic, etc.) that could influence air quality?

* weather (you can get it from the closest station on or if you don't have the instruments or want to compare to other places)
- temperature
- humidity
- barometric pressure
- wind
- uv index
why these values are important in relation to aerosols
Look at Globe aerosol protocol for explanations
smog city, EPA tool

* time of day

* measurements:
Sky Color Deep blue __ Medium blue __ Light blue __ Pale blue __ Milky __ Sky Clarity Unusually clear __ Clear __ Somewhat hazy __ Very hazy __ Extremely hazy __ Sky obscured by: Fog __ Smoke __ Haze __ Volcanic ash __ Dust __ Sand __ Marine spray __ Strong rain __ Strong snow __ Blowing snow __ (

cloud cover
Cloud Cover (%) No clouds (0%) __ Clear (0% - 10%) __ Isolated (10% - 25%) __ Scattered (25% - 50%) __ Broken (50% - 90%) __ Overcast (90% - 100 %) __ Obscured __

Image analysis tool: Image J

How far can you clearly see? Use Google Earth to chart distance.

2. Record the EPA air quality rating for your city (air quality index–color)

3. Look at MODIS true color; import into Google Earth
Clear instructions on how to import into Google Earth
Do you see haze/aerosols like what you saw from the ground?
How large is the haze event?
Does the image give you any clues about what is causing the poor air quality? Do you see evidence of transport?

Going further: look at weather map to guess where pollution may go

Download to Google Earth for analysis
Give instructions on how to download and save to Google Earth.
Link to smog blog or add annotated images to how to interpret a true color image
Import to Google Earth?
Note air quality color from

4. Repeat to determine variability over time
    Why? change over a day, weekday vs weekend, seasons– give user enough info to decide how frequently to make observations.

5. suggested comparison:
haze (rgb) vs epa air quality code
rgb vs air quality
time? Differences between locations?
what is the relationship between humidity and haze?
Is there a relationship between weather and haze?
Weather map

(barry lefer at university of houston–professor, research on atmospheric chemistry; partner organization with classes?)
Fairfax county–citizen measurements

? How is my air quality today?
? Does my air quality vary?

Level II - subjective observation + quantitative

1. Compare to MODIS true color 
Compare to true color MODIS and EPA air quality rating (air quality index–color)
Download to Google Earth for analysis
Give instructions on how to download and save to Google Earth.
Link to smog blog or add annotated images to how to interpret a true color image
2. Compare rgb to EPA air quality index (number) for pm 2.5 and ozone
3. AOT from IDEA for real time (IDEA Modis Terra regional plots from the IDEA home page - select region - then select region)  Can get numbers from (IDEA home page -  pick timeseries and correlations between Modis AOD and pm2.5 (bottom right at the moment) - select site - pick state - pick city or other location.  Record Modis value for day of interest.  For the brave.
use case studies to illustrate clean day, moderate aerosol, and heavy aerosols with photos, explain implications of total column in the measurement. Record an AOT value for your location as best as you can.
4. Compare AOT, pm 2.5, true color, fires, and pressure
How do these values relate to what you see on the ground?
5. Blog/online conversation about observations, analysis, questions, etc.
Global AOT
Additional references: smog blog
fires, pm 2.5, aod, true color, pressure?
3. Repeat and collect data at a community level

? Why (or why not) does the data agree with what I see? ———

Going Further - quantitative measurement
1. Take measurement using pyranometer using this procedure:

2. Compare to RGB, AOT, and EPA air quality index number

? How does the air quality vary over time and space?

Level III
1. Take measurement using handheld sun photometer
(adapt IESRE


Level IV
1. Take measurement using handheld sun photometer
2. Ground truthing
(adapt Globe)

Session 3: 3:15 – 5:00

  • Outline a sample analysis to show how someone would analyze a single image; explain why each step is important
  • Test procedure
* New South Wales AU "Measuring Visual Air Quality" (sample protocol)

* GLOBE air quality protocol for qualitative measurement