Student Name(s): _____________________________________________
Date: ______________________
Knowledge
Base
Select a
WOW lake to study for this lesson. Predict the greatest temperature
change you expect to observe during a 24-hour period during the summer.
Base this prediction on your knowledge and experience with lakes. Identify
the lake depth where you expect that change to occur. Enter your information
into Table 1.
Experimental
Design
The research
question to investigate is: "How much does a lake vary in temperature
during a 24-hour period during the summer?" Select a date during the
summer when there is temperature data available over a 24-hour period.
Enter the date into Table 1.
Data Collection
Complete
Data Table 1 with the data for the 24-hour period. Be sure to enter
the depth of the deepest reading. (If you have access to spreadsheet
software you may want to create a spreadsheet that replicates the table.)
What time
was your morning data collected? ______________
What time
was your afternoon data collected? ______________
What time
was your evening data collected? ______________
What time
was your night data collected? ______________
Data Table
1
WOW
Lake:
|
Date
studied:
|
Prediction
of greatest temperature change:
|
Predicted
depth of greatest temperature change (in meters):
|
Temperature Data
|
Depth
in meters
|
Morning
|
Afternoon
|
Evening
|
Night
|
Top
(1 m)
|
|
|
|
|
4
m
|
|
|
|
|
7
m
|
|
|
|
|
10
m
|
|
|
|
|
Bottom
= ___
m
|
|
|
|
|
Data
Management and Analysis
- Create
a line graph of your data (using either graph paper or spreadsheet
software.) Label your X-axis as time and your Y-axis as depth.
- Review
your data table and graph and answer the following questions.
- At
what depths or times is there missing or incomplete data?
- Look
for reasonable temperature values. Do the temperatures make sense
for this time of year? Which temperature readings might represent
some type of error? (Explain why you believe these might be erroneous
readings.)
Interpretation
of Results
- Use the
Internet, a newspaper, or other resource to identify and mark the time
of sunrise and sunset on your graph.
- Write a brief explanation of what your data shows. Relate your results
to what you know about temperature changes and/or to your personal
experiences with lake temperatures. Knowing that heat
energy is transferred through the process of conduction,
and radiation, describe the variables you believe may influence
temperature changes in a lake. Which of those processes appears to
lead to the greatest changes of temperature?
Reporting
Results
Turn your
results in to your teacher. You need to include your data table and
answers to questions 1-4. Also, include answers to the following questions.
(Base your answers on what you know about the transfer of heat energy
and what you have observed about temperatures in your lake over a 24-hour
period.)
- What was your initial prediction for the greatest temperature
change and lake depth for that change?
- Describe how the following might affect surface water temperatures:
- rain
- wind
- lightning
- sunlight
- cloud cover
- water clarity
- human activities
- geothermal energy (the temperature of the earth beneath a lake)
- Is there a thermocline located in your lake? At what depth?
- Between what time periods did the surface water temperatures change
most rapidly?
- How deep into the water column was temperature affected by surface
events?
- What might have happened to the air temperature above the lake's
surface as the surface waters cooled? Explain your thinking.
- How might a greater or lesser amount of wind affect the temperature
changes you observed?
- Explain how diel temperature changes might differ in:
- a crystal clear lake that is long, narrow, and 30 meters deep
- a bog-stained lake that is over 3 kilometers in diameter and
less than 3 meters deep
- a small creek without tree cover
- a spring-fed creek with full tree cover
|