MIT CCCT - 04 Evaporation over warmer oceans

Experiment: Evaporation over water of various temperatures

Compare the amount of water vapor in saturated air of various temperatures.

Time: 30 minutes

Level: Intermediate

Materials

For each group:

3 similar clear glass jars, 16 to 24 oz (500 to 750 ml) such as mason jars or pickle jars
Electric kettle or other device to heat water
Ice cubes
Plastic sheet to cover jars. Do not use “Saran” wrap as it will stretch under the ice. Sandwich bags cut apart will work well.
Rubber bands

Specifics and purchasing links are on this spreadsheet Materials list for CCSAE experiments

Procedure

Step 1

Prepare ice water and boiling water, about 500 ml or 2 cups for each set of 3 jars.

Step 2

Fill the 3 jars about 1/4 to 1/3 full with water of these temperatures:

Ice water
Boiling water
a 50%-50% mixture of boiling and ice water

Step3

Cover each jar with a thin plastic sheet and seal with a rubber band. Adjust the plastic and the rubber band so the plastic is flat and the jar is well sealed.

Step 4

Place a few ice cubes on top of each jar, and wait for about 5 minutes.

Step 5

After 5 minutes, remove the ice, dry the tops and observe the water droplets condensed on the plastic.

Tap the tops as needed to get the droplets to collect.

If there is not much condensation, replace the ice, and wait a few more minutes.

Record your observations (open the box to see our suggestions)

Suggestions:

More water droplets formed on the hot jar, and fewer water droplets formed on the colder jar.

Larger water droplets formed on the hot jar, and smaller water droplets formed on the colder jar.

The jars with warmer water had more condensation.

The most water vapor came from the warmest water.

Water evaporates, then condenses. This is the water cycle.

Identify the physical, chemical or biological mechanism that is happening (open this box after you have an idea)

The mechanism is evaporation

Warmer ocean waters cause more evaporation (more water goes into the air as vapor)

Relate this mechanism to climate change

Find the arrow (→) in the framework that represents this mechanism (starts at the cause phenomenon and goes to the effect phenomenon). (Use your printed copy of the framework, or open the one here.)

Pathway for Extreme and Changing Weather.pdf

Open this box to check your connection.

Then go to the Environmental Explainer pages to learn more about the Cause and Effect phenomena

Connection 4

Cause: Warmer ocean water

What is happening: there is more evaporation from warmer water

Effect: More water vapor in the air

The air over a warmer ocean will have more water vapor available to it than over a colder ocean

We’d love to hear how you used this tool in your community, how the students responded, and your suggestions to improve the experiments and other resources. Contact us at ccsae@mit.edu.