Foundational Earth Science GEOL-3012
Summer 2011
Land and Water Heating Activity
Introduction: Land and water influence the air temperatures above them in difference ways
because they do not absorb and reradiate energy equally.
Objective: To illustrate the different heating capacities of water and sand.
Lab Activity:
Step 1: Fill one beakers ¾ full with dry sand, a second beaker with water.
Step 2: Using a wood popsicle stick, suspend a thermometer in each beaker so that the bulbs are
just below the surface of the sand and water.
Step 3: Hang a light so that it equally heats both beakers.
Step 4: Record the starting temps for both beakers on Table 2.
Step 5: Turn on the light and record the temps at one-minute intervals for 10 minutes.
Step 6: Turn off the light for a few minutes. Dampen the sand with water and record the starting
temperature. Turn on the light and record the temp every minute for 10 minutes.
Step 7: Plot the temps (y-axis) versus time (x-axis) using a different color for each material.
Questions:
1. How do the abilities to change temperature differ for dry sand and water when they are
exposed to equal amount of radiation?
2. How do the abilities to change temperature differ for dry sand and damp sand when they are
exposed to equal amount of radiation?
3. Suggest several reasons for the differential heating of land and water.
4. How do the results of this experiment help explain this diagram?
5. Longer essay question: Thinking about the two activities which focused on albedo and
differential heating as well as the oceanography activities summarize all the factors that
determine the surface temperatures of the land and oceans. What factors determine whether an
ocean or land surface will heat up? You may want to treat these two bodies separately. What
does an increase (or decrease) depend upon? Try to encompass the various topics that this course
and lab have covered. Organizing your thought on this topic is the beginning of what modelers
do to develop Global Circulation Models (GCM’s) that attempt to predict climate or
oceanographic changes.