Energy from the sun is absorbed by Earth's surface
to heat the lower atmosphere. At times, however, much of this energy
is used to evaporate water in the form of dew or rain on the ground.
Hence, energy is diverted from warming the atmosphere to converting
liquid water to water vapor.
Objectives
Objectives
- To develop an appreciation for the effects of rain evaporation on temperature change.
- To better understand one segment of Earth's water cycle.
- Obtain ARM or Mesonet data for two nearby sites on the same day. The first site should have received more than 10 mm of rain the night before. The second site should have received no rain (preferable) or less than 1 mm of rain within the past 2 days. This case is most easily found in the warm months, when isolated thunderstorms commonly rain over one site but not on another. It should be relatively clear at both sites after sunrise.
- Use a full day of data starting with the previous evening.
| PROCEDURE 1. Plot the air temperature and incoming solar radiation for one site on one graph. Plot the same parameters for the second site on another graph. Use the same scale on the axes of both graphs. 2. Label the graph of the drier site "DRY" and the graph of the wetter site "WET." QUESTIONS 1. How do the temperatures change after sunrise at the DRY site? At the WET site? 2. In the first hour after sunrise, how much does the air temperature change for the DRY site? For the WET site? 3. In the first 3 hours after sunrise, how much does the air temperature change for the DRY site? For the WET site? 4. Does one site heat up faster than the other? If so, which one? 5. What process do you think is occurring to cause the differences in the heating rate? Are clouds affecting the heating rate at either site? 6. How could the process you indicated in Question 5 affect the day's weather? How could it affect a weather forecast? |
PREREQUISITES
Condensation Evaporation Solar radiation Water cycle CORE CURRICULUM SKILLS APPLIED IN THIS LESSON
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