Introduction to Oceanography: Abiotic
Air Temperature
Research Question: How does the air temperature affect the water of Long Island Sound?
Part A: Read the Background Information
Stratification and Mixing in Long Island Sound
The air temperature affects the water temperature, because heat can be transferred between air and water. When the air temperature is higher than the water temperature, this causes something called stratification in the water. The top layer of water, which is in contact with the warm air, heats up. Warm water is less dense than cold water, so the warm water stays at the surface, and the denser water underneath remains cooler. During times of the year when the air is warmer than the water, the water in Long Island Sound often has layers (stratification), with warm water in the top layers and cooler water in the bottom layers.
When the air temperature is colder than the water temperature, something different happens. The top layer of water, which is in contact with the cold air, cools down. Cold water is denser than warm water, so the cold water sinks to the bottom. This causes mixing of the water column. During times of the year when the air is colder than the water, the water in Long Island Sound is usually mixed, so there’s not much difference in temperature between the top and the bottom.
Part B: Prediction and Reasoning
Study the background information provided about air and water temperature. Write answers to the following prompts on your sheet of paper.
Field Notes
Sample Location: Mouth of the Thames River estuary. (View map here)
Time of Year: Students sampled the air and water temperatures every month for a year.
Method: Water Temperature samples were collected at the surface and the bottom of Long Island Sound.
1. Make a prediction: In what months of the year do you expect to observe stratification? In what months of the year do you expect to observe mixing?
2. Explain your reasoning. WHY do you think stratification and mixing will occur in those months?
Part C: Analyze the Data
Look at the data below. Students measured air temperature, surface temperature, and bottom water temperature every month for a year.
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Part D: Interpret the Results and Make Arguments from Evidence
Write answers to the following prompts on your sheet of paper.
1. Make a claim that answers the research question (one sentence).
2. What evidence was used to write your claim? Reference specific parts of your graph.
3. Explain your reasoning. Make sure to connect your answer to what you have learned about the effect of air temperature on stratification and mixing.
4. Was your prediction supported by the results? Use evidence to explain why or why not.
5. How would you follow up? Describe a new question that should be investigated to build on these results, and what future data should be collected to answer your question.
6. Extension: Stratification of the water can result in low oxygen levels at the bottom of Long Island Sound. Read this article from the Long Island Sound Study, and consider how low oxygen can affect organisms that live in Long Island Sound. Write a paragraph that (1) identifies an organism that could be affected by low oxygen in Long Island Sound, (2) explains how human activity might be affecting the low oxygen areas, and (3) describes one strategy that communities around Long Island Sound are using to combat the problem.
Congratulations! Your final analysis should include the following components:
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A statement of the research question that you chose/were assigned
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Your prediction and your reasoning
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Your answers to the results questions
Share your results with your teacher!