| A | B |
|---|
| solar radiation | Energy radiated from the sun in the form of electromagnetic waves, including visible and ultraviolet and infrared light. |
| atmosphere | The mixture of gases that surrounds Earth. The outermost of the four spheres into which scientists divide Earth. |
| radiation | The direct transfer of energy through empty space by electromagnetic waves. |
| infrared radiation | A form of energy with wavelengths that are longer than visible light. |
| visible light | The light in the electromagnetic spectrum that we can see, longer wavelength than infrared, shorter wavelength than ultraviolet radiation. |
| ultraviolet radiation | A form of energy with wavelengths that are shorter than visible light. |
| reflection | Cast back light or heat. |
| absorption | Taking in or reception by molecular or chemical action, as of gases or liquids. |
| solar energy | Energy from the sun. |
| carbon dioxide | Colorless, odorless, incombustible gas present in the atmosphere and formed during respiration. |
| greenhouse effect | The process by which heat is trapped in the atmosphere by water vapor, carbon dioxide, methane, and other gases that form a “blanket” around Earth. |
| convection | The transfer of heat by movements of a fluid. |
| density | The amount of mass in a given space; mass per unit volume. |
| thermal energy | The energy of motion in the molecules of a substance. |
| evaporation | The process by which molecules at the surface of a liquid, such as water, absorb enough energy to change to a gaseous state, such as water vapor. |
| condensation | The process by which a gas, such as water vapor, changes to a liquid, such as water. |
| thunderstorm | A storm of lightning and thunder, usually with rain and gusty winds, sometimes with hail or snow, produced by cumulonimbus clouds. |
| hurricane | A tropical storm that has winds of 119 kilometers per hour or higher; typically about 600 kilometers across. |
| electromagnetic wave | A form of energy that can travel through space. |
| cloud | A visible collection of particles of water or ice suspended in the air, usually at an elevation above the Earth’s surface. |
| hydrosphere | The water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere. |
| cumulus | Clouds that form less than 2 kilometers above the ground and look like fluffy, rounded piles of cotton. |
| stratus | Clouds that form in flat layers. |
| cirrus | Wispy, feathery clouds made mostly of ice crystals that form at high levels, above about 6 kilometers. |
| nimbus | Dense clouds or cloud mass with ragged edges, that yields rain or snow. |
| tornado | A rapidly whirling, funnel-shaped cloud that reaches down from a storm cloud to touch Earth’s surface, usually leaving a destructive path. |
| storm surge | A dome of water that sweeps across the coast where a hurricane lands. |
