us have experienced temperature variation in lakes. In the same lake,
a chilling morning swim becomes comfortable in the afternoon and then
cool again in the evening. The physics principles of energy transferred
as heat by
and/or radiation apply to lakes.
In this lesson you will explore temperature changes in a lake over a
24-hour period. You will explore temperature change at different lake
depths and hypothesize about factors that account for the changing daily
temperature of lakes.
question to investigate is: "How much does a lake vary in temperature
during a 24-hour period during the summer?" Based on your knowledge
and experiences, predict the depth where you would expect to find the
greatest change in temperature during a 24-hour period? How much change
in temperature would you expect to find at that depth?
of the WOW lakes for your investigation. As a scientist familiar with
lakes you know that lake temperatures vary throughout the day and at
depths. The RUSS instrument is collecting temperature data at about 1
meter intervals through the depth of the lake. In trying to answer
your research question, you need to make several decisions.
- For what
date will you collect your measurements? (Check the WOW data to make sure
data are available for that date.) Why did you choose this date to collect
- Will you
collect temperature measurements for all depths, or only selected depths?
- What range
of temperature measurements would you identify as "reasonable" for the
date you selected? How will you handle measurements that do not fall in
this range - measurements that might represent errors?
- What do you think would be a reasonable maximum change in temperature at any
depth of a lake during a 24-hour period in the summer? How will you
handle measurements that exceed this?
Use the WOW
web site to find the temperature data you need for your lake.
Management and Analysis
Create a table(s)
and record your results. If you have access to computer spreadsheets
you may want to create the table(s) on the computer to make it easier
your final results.
results of your table to show if there are any changes in temperature
at different depths during a 24-hour period.
Write a brief
explanation of what your data shows. Relate your results what you know
about temperature changes and/or to your personal experiences with lake
temperatures. Refer to your predictions. Knowing that
heat energy is transferred
through the process of conduction, convection, 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?
You need to
present a research summary of your investigation. Your teacher will specify
the format: a written paper, an oral presentation (like a presentation
for a scientific conference), a poster format (these are also often done
at conferences), or a multi-media presentation. Finish your research
by describing how you would like to extend or expand your collection
of lake data to more fully answer the research question.