NASA is taking part in the world effort to monitor changes in the environment of the Earth through its Mission To Planet Earth (MTPE) program. The MTPE program oversees the Earth Observing System (EOS) program. The goal of the EOS initiative is to develop the ability to predict environmental changes that occur naturally and as the result of human activity. Go to NASA's Earth science and EOS web sites to learn more about NASA's efforts.
It important to keep track of the Earth's radiation budget because the production of greenhouse gases seems to be affecting the natural balance. This creates concerns about rising sea levels, changing precipitation patterns, and an array of other possible effects. With the use of polar orbiting satellites, scientists hope to monitor changes in tropospheric and stratospheric temperatures to look for ways in which we are altering the Earth's radiation balance. The four topographical regions chosen to do this activity represent four distinctly different terrains. Each region has a predominant feature: rain forest, water, ice, or desert. Each has a unique albedo (reflectance), absorbance ability and heat capacity. These factors, among others, determine how the Earth interacts with the input of solar radiation.
As the diagram above shows, a variety of factors condition the Earth's radiation budget. Think of energy as money: instead of dollars, think energy units. In the case of money, "balancing the budget" requires that you know where every "dollar" was spent. In the case of the Earth, this means following the transformations of energy in the Earth system, through atmosphere to hydrosphere, and lithosphere and back again through the atmosphere. The Earth is in equilibrium with its surroundings, which means that the budget has to balance: energy going into the system must equal the amount exiting it. All life on Earth ultimately depends on that energy, even though the Earth receives only a very small percentage of the Sun's total energy output.
Many interactions drive the exchange of heat between the atmosphere and the Earth's surface features. One factor is that different surface features will have different abilities to absorb, reflect, and radiate energy. Earth's reflectivity, or albedo accounts for around 30% of the energy that approaches the top of Earth's atmosphere. Another factor, that single-handedly accounts for almost a quarter of the energy that enters the Earth system is due to the latent heat of water's transformation in the troposphere. Wind is a factor that further tunes the engine of the Earth's atmosphere and conditions the flow of energy through it. Part I of this investigation focuses on the interaction between the atmosphere and the Earth's surface features.
The global energy budget is made up of the simultaneous interactions of local energy budgets. Usually, the single most important factor that conditions a local energy budget is latitude, because this single factor limits the maximum and minimum amount of solar energy available to that location. The resulting variation in temperature from the Equator to the poles affects the patterns of heating and cooling around the Earth. These patterns drive atmospheric winds, ocean currents, and their interactions with weather and climate.
The learner should have the following skills:

Procedure: PART I:

1. Access the NASA Earth Systems Science Division:

2. Read "Current Deep Layer Temperature Patterns" to familiarize yourself with how the NOAA polor orbiting satellite data is collected.
3. Click Global under non-form selection pages .
4. Under Lower Tropospheric Temperature select 1:30 AM. This will bring you to an image which resembles the image below.

5. Using the following list choose coordinates for two locations and record your latitude and longitude in the upcoming data table.

Choose two of the following:
central Greenland.
Pacific Ocean (region south of Hawaii)
northern South America (Amazon Jungle region)
northern Africa (Sahara Desert region)

6. Create a data table which has the following format, or download the Student Handout found at the end of this document.


(latitude, longitude)
Date from Image__________
Local time
temp K°(lower troposphere)
temp K° (middle troposphere)
temp K° (lower stratosphere)
1:30 AM      
7:00 AM      
1:30 PM      
7:00 PM      
(latitude, longitude)
Local time
temp K°(lower troposphere)
temp K° (middle troposphere)
temp K° (lower stratosphere)
1:30 AM      
7:00 AM      
1:30 PM      
7:00 PM      
(latitude, longitude)
Local time
temp K°(lower troposphere)
temp K° (middle troposphere)
temp K° (lower stratosphere)
1:30 AM      
7:00 AM      
1:30 PM      
7:00 PM      
(latitude, longitude)
Local time
temp K°(lower troposphere)
temp K° (middle troposphere)
temp K° (lower stratosphere)
1:30 AM      
7:00 AM      
1:30 PM      
7:00 PM      

7. Using the color coded key below the image, determine the Kelvin temperature for each of your coordinate pairs for 1:30 am and record the temperatures in your data table.
8. Go back to the previous screen (using your browser--Click Back ) and repeat the above procedure for 7:00 am, 1:30 pm, and 7:00 pm until you have recorded all the data for the lower troposphere.
9. After completing the data collection for the lower troposphere, repeat the procedure for both the middle troposphere and lower stratosphere.

Use your data tables to answer the following questions.

  1. What is the dominant surface feature found at each your topographic regions listed in your data table?
  2. What season of the year is each site experiencing?
  3. Compare temperature fluctuations throughout the course of the day in each of the three atmospheric zones.
    1. Where do the largest fluctuations occur?
    2. Where are the fluctuations the smallest?
    3. Give possible explanations for what you have seen.
  4. What temperature trend is evident from the lower troposphere to the middle troposphere in each instance? How might you explain this trend?
  5. The solar absorption and radiation rates of the surface features at the four topographic regions in this investigation affect the way they interact with the atmosphere. Make a list of the four regions in order of best absorber of radiation to the worst absorber. Justify your answer.
  6. According to the NASA "Looking At Earth From Space" glossary of terms booklet, the word troposphere comes from the Greek word, tropos, which means turning or mixing. Which of the three methods of heat transfer would most likely support this description?
  7. Give a possible explanation for the temperature decreases from the lower troposphere to the middle troposphere.
  8. How do you think the temperature changes in the troposphere and stratosphere help to balance the Earth's radiation budget?

Procedure: PART II:

Ground-truthing is an important aspect of understanding the Earth. Global satellite readings must be calibrated and integrated with measurements taken locally from the ground.

Go to the GLOBE website and click on "Find Out", then on "Students" to understand the international efforts of students to help scientists in this process.

  1. Go to the map pages of the GLOBE website. Select a locality close to the ones you used in Part 1, above, and examine its minimum, maximum, and current temperatures.
  2. Compare this map with the satellite data graphs of the lower troposphere, which you obtained in part one, above. Note similarites and differences.
  3. Explain why satellite data was in some case not in agreement with the ground data taken by GLOBE students at their school monitoring stations.

Items to be Printed:

The learner needs a printed copy of the data tables in Part I and Part II.

Resources: NASA data used in Part I and Part II. --NASA site providing text and drawing pertinent to this investigation. --contains a large variety of GOES images of clouds. --provides links to a variety of atlas images. --MTPE site. --E0S site.

Maryland Core Learning Goals (Science): 2.2, 2.3
National Standards (Science): A.2, A.3
National Standards (Geography): 1
National Standards (Mathematics): 4.4, 5.2





The NASA Water Vapor Project (NVAP) is a blended analysis of global water vapor present in the atmosphere. This project combines retrievals of precipitable water (or water vapor) from ground-based radiosondes, in microwave frequencies from the Special Sensor Microwave/Imager (SSM/I), and infrared TOVS observations from the NOAA operational series of satellites. This data-set spans 5 years, from 1988 - 1992 and gives some opportunity to observe a base-line for the amount of water vapor present in the atmosphere. Clouds are liquid water droplets that condense out of water vapor and, in the process, release vast amounts of heat. (Recall that almost a quarter of the Earth energy budget is caught up in the condensation and evaporation of water.) thus the study of water vapor, precipitable water and clouds are very important to understanding the energy budget. Precipitable Water is the amount of water which would be obtained if all the water vapor contained in a column of the atmosphere was condensed and precipitated.


1. Click Here to access NVAP data.
2. Under the picture of the CD click Frames Version
3. In the left margin you will see Data Accessible from the Web. Click on it.
4. Click View Browse Images under NASA Water Vapor Project (NVAP) Data
5. Under Data Set click and choose precipitable water.
6. Under date click and choose July for the month and 1988 for the year.
7. Under Level (for precipitable water only) choose surface-700 mb.
8. Click view image.
9. Answer the following questions.

Directions: Answer the following on your own paper.
1. What are the units for the precipitable water vapor found in the images?
Observe the month of July for each year from 1988 to 1992 and answer each of the following questions.
2. Give the values for the highest concentrations of precipitable water vapor found in your image and describe their locations.
3. Give the values for the lowest concentrations of precipitable water vapor found in your image and describe their locations.
4. Does the location of the highest precipitable water vapor over the five year period remain constant? If not, cite examples where it varies.
5. Does the location of the lowest precipitable water vapor over the five year period remain constant? If not, cite examples where it varies.
6. In general would you say that the concentration of precipitable water vapor over the five year span remained stable?
7. Write a short paragraph explaining why you think monitoring global cloud cover can assist NASA in learning about the Earth’s radiation budget.
8. Do research on the Greenhouse Effect and relate your data to what you learned in this investigation.
9. Make predictions for temperatures at each of the atmospheric zones for each of the sites you chose in Part I for a day six months in the future. Come back and check your predictions and explain your observations.
10. Cloud cover is a very important factor in the earth’s radiation budget. Consult the NASA Facts url at
This site gives some excellent background and data related to this relationship. Read this fact sheet and produce a list of ways you think cloud cover may affect temperatures in the lower troposphere, middle troposphere, and lower stratosphere. Make predictions about how this might show up on your satellite images from Part I.
11. Do more research on the Earth’s Radiation Budget. Read the NASA EOS Educator’s Visual Materials document ID: 1-03 Outgoing Longwave Radiation, 1985-1986 as a starting point.
To access this document Click Here,


Daniel Hortert, Principal Investigator
Lisa Bruck
Craig W. McLeod
Marijke McMillan