Why is it Hotter at the Equator?

Atmospheric Radiation Measurement (ARM) Climate Research Facility
Type Category
Instructional Materials
Activity , Experiment/Lab Activity , Lesson/Lesson Plan
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



The students investigate the heating effects of light striking a surface at angles varying from 0 to 90 degrees. Temperature data is collected over time and graphed. They gather and analyze data and explain how direct light at the Equator results in a warmer climate. Students describe temperature patterns at locations poleward from the Equator. This illustrates the heat differential on Earth based on the angle of incoming sunlight at latitudes north and south of the equator. Questions and follow-up activities are provided. Suggested follow-up activities include writing about the temperature patterns and gathering climate and weather data from other sources to compare to their experiment. A PDF document of the entire activity includes student sheets. The instructions state that it would take 60 minutes to complete the activity. Please note: Teachers should experiment with the setup and the covering of the thermometers because the top of the vertical thermometer is closer to the light than the others and it may impact the results.

Intended Audience

Educational Level
  • Grade 8
  • Grade 7
  • Grade 6
  • Middle School
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

MS-ESS2-6 Develop and use a model to describe how unequal heating and rotation of the Earth cause patterns of atmospheric and oceanic circulation that determine regional climates.

Clarification Statement: Emphasis is on how patterns vary by latitude, altitude, and geographic land distribution. Emphasis of atmospheric circulation is on the sunlight-driven latitudinal banding, the Coriolis effect, and resulting prevailing winds; emphasis of ocean circulation is on the transfer of heat by the global ocean convection cycle, which is constrained by the Coriolis effect and the outlines of continents. Examples of models can be diagrams, maps and globes, or digital representations

Assessment Boundary: Assessment does not include the dynamics of the Coriolis effect.

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
The students construct a hypothesis, gather and graph data and write a conclusion based on their data. They draw a representation (model) of sunlight hitting the Earth that illustrates their conclusion. The follow-up activities ask students to track longitudinal data for various locations on Earth, providing a picture of regional climates. The teacher would need to introduce other activities to address the rotation of the Earth and the resulting patterns of atmospheric and oceanic circulation such as trade winds. An activity that illustrates oceanic circulation can be found at http://mynasadata.larc.nasa.gov/lesson-plans/lesson-plans-middle-school-educators/?page_id=474?&passid=9. The resource is reviewed under the title “Ocean Currents and Sea Surface Temperatures.” Students should be able to apply the effects of differential heating on the ocean to the atmosphere through a discussion of the behavior of fluids whether they are gas or liquid.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
The students analyze the data they have gathered in the investigation and write a conclusion based on their quantitative data. The representation that they draw of sunlight hitting the Earth examines the cause of the differences in the data. Questions provided in the handout point out the correlation between angle of sunlight and temperature. To address basic statistical techniques of data and error analysis, the teacher could ask about variations and outliers in student data and the students could discuss possible causes.

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
Students investigate the interaction of sunlight and Earth’s surface through the use of heat lamps and thermometers covered in black paper. The black paper serves as the surface of the earth that absorbs solar energy and the angles of the thermometers represent the surface of the Earth at different latitudes. To include the interactions with the ocean, the atmosphere, and ice, the thermometers could be immersed in water or ice and left uncovered for the atmosphere. Variations due to altitude and local and regional geography could be included as further extensions in the follow-up activities. Students could gather and compare data from other resources on 2 locations with the same latitude but different altitudes, on locations next to oceans versus areas in the middle of large continents. Suggestions for addressing oceanic and atmospheric flow patterns are described above.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
Students are asked to interpret patterns in the data. They are ask to identify the pattern in the cause-and-effect relationship between the angle of sunlight and temperature on Earth. The more direct the angle the more concentrated the energy is at that latitude and the greater the rise in temperature.

Resource Quality

  • Alignment to the Dimensions of the NGSS: Grade-appropriate elements of the science and engineering practices, disciplinary core ideas, and crosscutting concepts work together to support three-dimensional learning to make sense of phenomena. The students engage in the practices of analyzing and interpreting data and developing models to describe how sunlight creates unequal heating of the Earth resulting in varying regional climates. They determine the cause and effect relationship between the angle of sunlight and resulting temperatures. The activity develops deeper understanding of the three dimensions. Because of the scope of the Disciplinary Core Idea related to this activity, additional instruction will be needed to address all the concepts stated therein.

  • Instructional Supports: The activity engages students in a meaningful scenario that reflects the practice of science in the real world and provides students with a purpose. It engages them in multiple practices that work together with crosscutting concepts and disciplinary core ideas to support students in making sense of a phenomena. It builds on students’ prior knowledge when they are asked to construct a hypothesis and provides opportunities for them to interpret phenomena when they analyze their data. The follow-up activities allow for some differentiated instruction for students who have met the performance expectation as well as some activities for students with special needs. The PDF provides background information for the teacher as well as key vocabulary.

  • Monitoring Student Progress: The student record sheet provides opportunity for formative assessment of student understanding after the data is gathered and graphed and students answer questions and draw models. It elicits direct, observable evidence of student use of the practices, crosscutting concepts, and disciplinary core ideas in multiple representations. No rubrics or scoring guidelines are provided. No correct answers are provided for the teacher.

  • Quality of Technological Interactivity: Technological interactivity isn't required in this lesson. The activity requires the use of basic scientific instruments such as thermometers and heat lamps. The Internet is used as a resource for the follow-up activities to research climate and weather information from various sites around the world.