A World of Weather, Edition 3: Chapter 2 Introduction

CHAPTER 2

SOLAR AND TERRESTRIAL RADIATION Light from the sun travels through space in a blur, covering the 150,000,000 km to Earth (about 93,000,000 mi) in a cosmic blink of about eight minutes. But the solar energy that whizzes through space is more than just visible light. It is an ensemble of visible and invisible energy that we call solar radiation. Though the word "radiation" sometimes has negative connotations, the heating provided by solar radiation maintains life on this planet and drives the earth's weather machine.

The sun is not the sole controller of the earth's thermostat. The earth and everything on it (called terrestrial objects) emit energy. This terrestrial radiation also plays a primary role in how our planet warms and cools. Solar and terrestrial radiation are the heartbeats that pump lifeblood into earth's weather. This is their story.