Climate and Earth's Energy Balance

Introduction

The sun rises every morning, lights our day, drives the processes of weather, gives plants the fuel to grow, moves ocean currents, and gives us warmth. In fact, one could say that Earth is solar powered. As you saw in the previous lab, annual seasonal changes in weather control the cycles of growth in plants such as trees. These cycles of change are dramatic and yet subtle, so much so that we often go about our busy lives without even noticing them. In some parts of the world, specifically at the higher latitudes, such as in New England, the amount of sunlight can be very seasonal, changing noticeably from summer to winter. In other places, closer to the equator, it shines with almost the same intensity every day of the year. Have you ever stopped to think how important the sun's energy is to your daily life?

The primary drivers of climate are: incoming solar radiation, Earth's revolution and rotation, the surface features of the land, and the composition of the atmosphere. In this lab, you'll explore two of these controls, the incoming solar radiation and the composition of the atmosphere. You will view interactive graphics that show the distribution of Earth's energy budget and you will complete several labs that demonstrate how energy is trapped by atmospheric greenhouse gases and used to drive the water cycle. You'll develop a sense of how energy comes from the sun, what processes it drives, and how it is returned to space, keeping Earth's energy budget constantly changing, but balanced.

After completing this Lab, you should be able to:

• describe how incoming solar radiation is reflected, absorbed, and transferred throughout the Earth system;
• model Earth's energy flow and budget, both qualitatively and quantitatively;
• list the major greenhouse gases and their role in Earth's energy balance; and
• describe the role of the water cycle in maintaining Earth's energy budget.

Keeping Track of What You Learn

In these pages, you'll find three kinds of questions.

• Checking In questions are intended to keep you focused on key concepts. They allow you to check if the material is making sense. These questions are often accompanied by hints or answers to let you know if you are on the right track.
• Stop and Think questions are intended to help your teacher assess your understanding of the key concepts and skills. These questions require you to pull some concepts together or apply your knowledge in a new situation.
• Discuss questions are intended to get you talking with your neighbor. These questions require you to pull some concepts together or apply your knowledge in a new situation. There is no right answer to these questions; just something to ponder.

Your teacher will let you know which questions you should answer and turn in.