SST Lab

by Sci5

Fifth graders at Fieldston Lower start their year in science studying hurricanes. As we observed the storms Ian, Karl, Matthew and Nicole, we noticed that the storm seemed to be a lot stronger when they were over warmer water. That got us thinking, there must be a relationship between evaporation and sea surface temperature (SST). So, we designed a lab to find out if evaporation and SST were related.

Read on to see our lab report:

How does SST affect the intensity of a storm?

We thought that the cooler the ocean is, the weaker the storm will be. We also thought that when the ocean is warmer, the storm will get stronger. These ideas came from our observations of Tropical Storm Ian and Tropical Storm Karl. The test our hypothesis, we made an experiment where we tested the humidity, the air temperature and the water temperature in a closed environment. We did this lab because we wanted to learn what makes tropical storms stronger and weaker.

In our lab, we used a beaker with some water in it to represent the ocean and placed a plastic box on top of the beaker to represent the atmosphere. We used a tool called a LabPro to collect humidity, air temperature and water temperature data. We did the experiment with different temperatures of water in the beaker to test warmer and cooler sea surface temperatures.

Collecting Data

After doing several trials, we found the mean average humidity for each temperature of water that we tested.

This graph shows the increase of the humidity with warmer water temperatures. It shows that between each temperature change the humidity rises by a large amount at first. As the water gets into the 40 to 50 degree area, then it doesn’t change that much. We think this is because at that temperature, there is too much water vapor in the air, so it starts raining down. That leaves the same amount of water vapor in the air. We actually observed “rain” in our apparatus at the warmer temperatures. Droplets of water collected on the inside of the plastic box and then started to drip back into the beaker.

Based on our data, sea surface temperature definitely affects how quickly the surface water will evaporate. That puts more moisture into the air and feeds the tropical storms. That’s why the storms get stronger over warm water and weaker over cool water.