titleText=GLOBAL ENERGY BUDGET &subtitleText2=What happens to the energy in sunlight after it falls on Earth? &titleText3=THE CAST OF CHARACTERS &subtitleText3=Sun, Energy, Earth and Atmosphere &greenhouse1=The Sun radiates energy and some if it falls on Earth. Sunlight is the source of most of the energy we use every day, whether we use solar, wind or fossil fuels. Sunlight warms the planet to a certain temperature and fuels the motion of wind and water. Without sunlight the Earth would colder, and nearly still and lifeless. &subtitleText=What happens to energy once it enters the Earth's atmosphere &percentText=When sunlight crosses the top of the atmosphere it is cosidered to have arrived or landed on Earth. Some of it passes through the thin atmosphere and heats the Earth's surface, landing not just on the solid ground but also on the sea surface. In our diagram, we imagine ALL the sunlight that lands around the ENTIRE Earth and represent it by a single arrow labeled 100%25. Since the birth of the Sun and its planets ~4.5 billion years ago, sunlight has been falling on Earth every day. Where is all that energy today? &percentText2=Energy also returns to space. It doesn%27t accumulate. Thus there is an approximate balance between the amounts of energy that come in and go out. The amount of energy that heats the surface and atmosphere, and sets climate, remains relatively constant over time. If a dollar%27s worth of energy or 100%25 falls on Earth over time, how is that dollar%27s worth of energy distributed once it arrives, and how does the entire dollar exit? &visibleLightText=Sunlight is either reflected or absorbed by the materials that make up Earth. &visibleLightText2=REFLECTION - 30%25 of the sunlight is reflected or bounced right back to space without heating the Earth. It bounces off of reflective objects such as water droplets that make up white clouds, molecules and atoms in the air, and the ground. Some things are more reflective than others. With respect to sunlight, it lands on Earth when it encounters the atmosphere. &visibleLightText3=ABSORPTION - 70%25 or most of the sunlight is absorbed by materials that make up the Earth and atmosphere. When sunlight is absorbed, the energy in sunlight becomes temporarily held by the atoms and molecules that make up the ground and atmosphere. Half of our dollar%27s worth of the Sun%27s energy is absorbed by the ground made up of land and ocean. A little bit is absorbed by water molecules that make up the clouds that also reflect sunlight and shade the Earth. Some of it is absorbed by molecules and atoms in the air such as water vapor and carbon dioxide, although relatively very little and most sunlight just passes through to the ground. &visibleLightText4=The materials that make up the Earth have absorbed 70%25 of the Sun%27s energy. That energy has warmed the surface of the Earth, provided the energy that moves water and wind, and the energy that supports life through photosynthesis. While the Sun%27s energy is doing all of these things, it has changed form and does not exist as radiation. For example, some of the Sun%27s energy maybe in the sugar you just ate, or in the electricity that powered your toaster that came from a solar-generated power plant, or in the motion of... But how does it all get back to space? &cycleTitle=Global Energy Balance &cycleSubtitle=How energy returns to space &cycle1=Eventually all the materials that absorbed the Sun%27s energy naturally let it go. Letting the energy go is called emission. It happens in several ways depending on the materials that absorbed the energy. Ultimately, energy has to be converted to radiation in order to go back out to space. Click on each type of emission to explore. &cycle2=LATENT HEAT - Some of the energy is returned to space by the water cycle. When water evaporates, molecules of water vapor carry energy into the atmosphere. When it condenses and forms water droplets that make up clouds, it releases energy. If that energy is radiation and pointed spaceward, it escapes the Earth. How to remember which process %2D evaporation or condenstation %2D absorbs and uses energy rather than emits and releases it: When you carry water uphill against gravity, which is what evaporation does, it requires energy just like you would. Because evaporation carries so much water against gravity every day, a huge amount of energy is carried into the atmosphere by this natural process every day. It is called latent heat or hidden heat because unlike heat that raises temperature, this energy within air cannot be detected by a rise in temperature... &cycle3=IR - Relatively warm objects emit infrared radiation. When the ground is relatively warm compared with the atmosphere, it radiates infrared radiation or heat to the air. Some of that radiation escapes directly to space and much of it gets absorbed by water and carbon dioxide molecules in the atmosphere. Gases that absorb IR are called greenhouse gases. They intercept outgoing IR and keep it around a while longer, keeping the surface of the planet warmer than it would have been without the greenhouse gases. Eventually, even greenhouse gases emit energy, but some of it gets reabsorbed by substances on the ground and the atmosphere before it all works its way out of the Earth system. IR is called longwave radiation because the wavelength of IR is longer than for visible light or UV. &cycle4=SENSIBLE - &waterVaporTitle=WATER VAPOR TITLE &waterVaporSubtitle=Water Vapor Subtitle &waterVapor1=What happens? &waterVapor2=Zooming and wavelengths &waterVapor3=Moving &waterVapor4=Scene4 &waterVapor5=Scene5 &waterVaporTitle2=VISIBLE LIGHT &waterVaporSubtitle2=From the Sun &waterVaporTitle3=INFRARED RADIATION &waterVaporSubtitle3=From the Ground and Sea Surface &planeText=combustion