One of the most interesting features of Earth, as seen from space, is the ever-changing distribution of clouds [see Figure 1]. They are as natural as anything we encounter in our daily lives. As they float above us, we hardly give their presence a second thought. And yet, clouds have an enormous influence on Earth’s energy balance, climate, and weather.

Cloud systems also help spread the Sun’s energy evenly over Earth’s surface. Storms move across the planet and transport energy from warm areas near the equator to cold areas near the poles. For more details on the topic of Energy Balance, refer to NASA Facts 2005-9-074- GSFC.