Lab 8: Earth as a System Poster Activities

Note: The title needs to communicate its specific topic within the unit. Ideally, it should be compelling to high school students, or at the very least, not dreadfully boring.

The lab activity described here was created by AUTHOR of AUTHOR's AFFILIATION for the EarthLabs project.

Activity Summary and Learning Objectives

Images displaying global environmental data through the course of 2007 are compared in order to understand how the Earth works as a system. Extension activities connect the Earth System Poster to external websites (e.g., NASA, NOAA, NSIDC, and SERC).

After completing this investigation, students will be able to:

• explore the concepts of Earth as a System;
• find patterns and connections between and among maps containing different environmental data; and
• understand the relationship between time and space in regard to global environmental data.

Context for Use

This text should describe the teaching situations for which this activity is appropriate. At what point within a unit is it appropriate? Is it an introductory activity, a tangential concept, or a culminating project? How much time does it take? Does it require a computer lab, lab equipment, or other items? Does it require breaking the class into smaller groups? Are there prerequisite skills or concepts?

Time:One class period

Level:Middle, Secondary

Activity Overview and Teaching Materials

This section will help teachers see the overall flow of the activity as well as its pieces. Write a sequential narrative describing the mechanics of the activity. Include embedded links to all electronic materials needed to complete the activity.

Upload and make a link to a word processing file that contains all the Stop and Think questions: make an explicit invitation for teachers to add or modify questions to meet their content needs. Also, generate and post a PDF file that contains a reasonable range of answers to the questions; consider that a teacher might use this as a key to have students check their own work, or to have student aides grade submitted answers.

Teaching Notes and Tips

This section should include information for instructors who are getting ready to use the activity. Address things that might cause confusion, things that need reinforcement, safety guidelines, and other practical tips. This section should complement, rather than repeat, the more general guidance offered on the Activity Sheet. Much of this info might come from field testing.

Assessment

This section should describe at least one way the teacher can determine whether or not students (either individually or collectively) are achieving the learning goals outlined for the activity. The simplest instance of assessment is comparing student answers to the Stop and Think questions with the answers provided. More complex assessments may also be appropriate. Including a rubric that both students and teachers could use to assess student work can be very useful.

State and National Science Teaching Standards

Additional Resources Only list the sub-headings here for which you have valuable resources to offer

Background Information

Earth as a System
The processes comprising the Earth's environment are interconnected. Understanding how these connections operate on a global scale is to understand the Earth as a system. Understanding the Earth as a system requires a quantitative exploration of the connections among various parts of the system. These processes take place in the atmosphere, oceans, fresh water, ice, soil, and vegetation. These processes also include energy from the Sun, and gases and particles that enter the atmosphere and oceans from both natural and anthropogenic, or human caused, sources.

The following activities will help students to understand variations in environmental parameters by examining connections among different phenomena measured on local, regional, and global scales. As students look at the connections between and among environmental data, they will see that the environment is the result of the interplay among many processes that take place on varying time and spatial scales. They will also understand that environmental processes are not bound by country delineations but rather are even able to cross oceans. 

Additional information on the data and imagery used for this poster is available in Appendix A. Teachers may choose to distribute this information with the images.

Aerosols
The atmosphere is made up of molecules of gas as well as small solid and liquid particles suspended in the air, called aerosols. Some aerosols are naturally produced from volcanoes, sea spray, sand, or wind-drive erosion of surface soil. Some aerosols are the result of human activity, such as dust from agricultural activities, smoke from burning plants and fossil fuels and smog due primarily to vehicle emissions. Small water droplets and ice crystals are also considered aerosols. 

Most aerosols are in the troposphere, but large volcanic eruptions can send aerosols and trace gases much higher into the stratosphere, sometimes cooling surface air temperatures around the world for years at a time. Aerosols in the stratosphere may remain for years while in the troposphere, precipitation and interactions with Earth's surface usually remove aerosols in usually less than two weeks.

While aerosols are too small to see individually, when combined in the atmosphere they may make the sky look hazy or dirty. Orange or red-orange skies at sunrise or sunset can also indicate aerosols in the atmosphere—between the viewer and the horizon.

Aerosols also influence Earth's weather and climate; they affect the amount of sunlight reaching the planet's surface by reflecting and absorbing light. Burning of biomass, wood, and other plant material, causes an increase in local aerosol concentrations that can affect weather regionally. Aerosols are also very mobile, carried by the wind and therefore able to cross oceans and mountain ranges. Dust storms in Northern Africa often cross the Atlantic Ocean, depositing dust and other particulates as far wast as the Caribbean Sea and the Gulf of Mexico. For more information, see the NASA TERRA Aerosols Fact Sheet.

Insolation
Insolation (incoming solar radiation) is the rate of incoming sunlight reaching the Earth's surface measured in Watts per Square Meter (W/m²). The amount of solar energy reaching the Earth's surface varies due to air molecules, clouds, and aerosols. These images are derived from measurements of radiant energy escaping the top of Earth's atmosphere by the CERES instrument aboard NASA's Terra and Aqua satellites.

Surface Temperature
Surface temperature images are a compilation of Land Surface Temperature (LST) and Sea Surface Temperature (SST) images measured in degrees Celsius (°C). LST is measured by MODIS (Moderate Resolution Imaging Spectroradiometer) aboard NASA's Terra satellite, while SST is measured by AMSR-E (Advanced Microwave Radiometer for EOS) aboard NASA's Aqua satellite. AMSR-E's analysis product is able to merge data from AMSR-E (which has microwave ability to see through cloud cover), MODIS (which has higher spatial resolution, but cannot measure through clouds, and TMI (TRMM Microwave Imager).

Cloud Fraction
Cloud fraction is the portion of Earth's surface covered by cloud relative to the portion of Earth not covered by cloud expressed in a percentage (%). Cloud fraction is measured using MODIS (Moderate Resolution Imaging Spectroradiometer) aboard NASA's Terra and Aqua satellites. MODIS collects information in pixels with resolution of one square kilometer. Scientists count the number of pixels that are cloudy in a 25-square-kilometer area and dividing that number by 25.

Total Rainfall
Total rainfall is derived from data collected by the Precipitation Radar instrument aboard the Tropical Rainfall Measuring Mission (TRMM) measured in millimeters (mm). TRMM is a joint mission sponsored by NASA and the Japanese Space Agency (JAXA). TRMM's orbit is near the equator, so its field of view is limited to Earth's tropical and sub-tropical regions—between 35 degrees north and south latitude; therefore, TRMM cannot measure rainfall at high latitudes or in Earth's polar regions.

Aerosols
Aerosols are small solid and liquid particles suspended in the air. Aerosol Optical Thickness (AOT) is determined by the amount of visible and near-infrared light reflected back into space by particles in the atmosphere—or a measure of how much light these airborne particles prevent from traveling through the atmosphere to the surface of the Earth. Aerosols data includes optical thickness and size distribution of aerosols over most of the globe on a daily basis. This information is used to study aerosol climatology, to monitor the sources and sinks of specific aerosol types (such as industrial/urban aerosols and biomass burning aerosols), to serve as inputs for climate modeling and detection of the finger prints of anthropogenic climate change, and to perform atmospheric corrections of remotely-sensed surface reflectance over the land.

Biosphere
Biosphere images are composed of Chlorophyll Concentration and NDVI (Normalized Difference Vegetation Index) images. Chlorophyll a (alpha) is a pigment found in phytoplankton (tiny aquatic organisms). Its concentration, measured in milligrams per cubic meter (mg/m³) is used as an index of phytoplankton biomass and, is a key input to primary productivity models. MODIS, aboard NASA's Aqua satellite, measures chlorophyll a daily over the entire planet. NDVI images show a global measure of the "greenness" of vegetation (ranging from -0.1, low vegetation, to 0.9, maximum detectable vegetation) across Earth's landscapes for a given composite period. These images are accurate measures of vegetation activity (chlorophyll concentration) at the land surface. NDVI images were made using data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra satellite. As plants, both aquatic and terrestrial, grow they take in carbon dioxide during photosynthesis.

Pedagogic Considerations

Describe why this teaching technique is well-suited to this content or include links (with descriptions) to references that provide support for the pedagogy.

Content Extension

For teachers who want to be a bit over-prepared or students who would like to take their learning further, provide links to relevant sites here. For each link, give a brief description of what the site offers. Where possible, link to the pages that are most specific to the activity rather than to the top page of major Web sites.