# Part 4—Identify and Investigate Anomalies

## Step 1 – Explore Morgan Lake, New Mexico

1. Turn off all data layers.
2. Use the Google Earth search box to "Fly To" Morgan Lake, New Mexico.

3. To see what the area is like, zoom out to an Eye Altitude of about 60 km (40 miles). Read the "Eye alt" value shown in the extreme lower-right of the Google Earth window.
4. Turn on the Population Density layer to check how many people live within this area of New Mexico. Based on your observations, make a prediction about the NO2 concentrations you would expect to find in this area.
Based on the rural appearance and relatively low population density, NO2 concentrations will be low.

## Step 2 – Explore the Relationship between Population and NO2 Concentration

1. Turn on the January 2010 NO2 concentration layer and interpret it for this area. What is the NO2 concentration like for the area around Morgan Lake?
NO2concentrations are relatively high (yellow).
2. Hypothesize one or more possible explanations that could account for high NO2concentrations in a sparsely populated area of New Mexico?
• The area could have a lot of cars that put NO2 into the atmosphere.
• The area could be surrounded by mountains that trap NO2.
• The area could have a power plant that produces NO2.
• Lake processes at Morgan Lake could be producing NO2.
3. Look for evidence to support your hypothesis. For instance, if you thought mountains around the area were trapping the NO2, zoom out, or examine the terrain to see if you were right.
4. If you looked into the location of power plants in the area, you'd find that the Four Corners Power Plant is located nearby. This coal-burning plant supplies electricity to many locations in Arizona, California, New Mexico and Texas. Burning coal at this plant is responsible for producing nitric oxide that is leading to the production of nitrogen dioxide. To locate the plant, type its name into the "Fly To" box.
Burning coal accounts for about 21% of the energy produced in the United States each year. Of this, 88% of it is burned to produce electricity. The by-products of burning coal include hydrocarbons and sulfur dioxide among other pollutants. This can contribute to the formation of many types of smog (including photochemical).

Sources: Plummer, C.C., & Carlson, D.H. (2007). Physical Geology (12th ed.). New York: McGraw-Hill.
U.S. Department of Energy, U.S. Energy Flow by Source and Sector. Total Energy Production by Source

## Step 3 – Examine Seasonal Differences around Morgan Lake

Turn on the May 2010 NO2 layer and compare it to the January image for the same location. Consider the following questions:

• When are the NO2 concentrations higher at Morgan Lake, during January or May?
January has a higher NO2 concentration than May.
• Hypothesize one or more possible explanations for NO2 concentrations near Morgan Lake being higher in January than in May.
• The Four Corners Power Plant may be more active during January than May because people need more electricity to run lights and heaters during January than in May.
• Weather and wind patterns may be different in the two seasons, resulting in lower concentrations of NO2 during May because the NO2 is spread over a larger area.

## Step 4 – Consider Questions for Further Exploration

Photochemical smog is a serious environmental problem for human health. It is also a factor in reducing visibility at places such as National Parks. State and federal agencies are continually implementing new rules and regulations to govern emission allowances for automobiles, power, and manufacturing plants. Societal needs for cleaner air influence the technological development of better "scrubbers"systems designed to remove dangerous waste before they are released into the environment from smoke stacks.

Devices called catalytic converters are one part of the scrubbing process: they use catalysts to alter the composition of by-products produced in combustion engines. They can change residual hydrocarbons, oxides of nitrogen, and carbon monoxide into less harmful substances, but they are costly to implement.

Use visual inspection to look for other areas that have elevated NO2 concentrations without high population density. Ponder the following questions:

• What suggestions can you make to reduce NO2 pollution from automobile emissions?
• Given that technology exists to reduce NO2 emissions from fuel combustion (e.g., catalytic converters), why do you think more is not being done to mitigate this problem?
• What might be done to reduce NO2 production?
• The most direct way to reduce NO2 is to drive fewer miles in your car. Combining errands and going fewer places in order to cut back on the number of vehicle miles driven per year will reduce NO2 in the atmosphere.
• Investment in research and development of low-cost catalytic converters to change the composition of vehicle exhaust to less harmful substances could reduce NO2 production.
• Efforts to reduce the production of NO2 may not be implemented because manufacturers may perceive that the costs would reduce their profits.
• Electric cars are now becoming more available. These offer opportunities for localized exhaust emission reduction. However, a large amount of electricity is produced from the burning of coal, and so the problems of smog may be merely displaced to a different location. Solar energy is one viable alternative.

For further research into these issues, find information at the Environmental Protection Agency (EPA) or the U.S. Energy Information Administration (EIA)