| A | B |
| ELECTROMAGNETIC WAVES | A form of energy that can travel through space. |
| 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. |
| ULTRAVIOLET RADIATION | A form of energy with wavelengths that are shorter than visible light. |
| SCATTERING | Reflecting of light in all directions. |
| 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. |
| THERMAL ENERGY | The energy of motion in the molecules of a substance. |
| TEMPERATURE | The average amount of energy of motion in the molecule of a substance. |
| THERMOMETER | An instrument used to measure temperature, consisting of a thin, glass tube with a bulb on one end that contains a liquid (usually mercury or alcohol). |
| HEAT | The energy transferred from a hotter object to a cooler one. |
| CONDUCTION | The transfer of heat from one substance to another by direct contact of particles of matter. |
| CONVECTION | The transfer of heat by movements of a fluid. |
| WIND | The horizontal movement of air from an area of high pressure to an area of lower pressure. |
| ANEMOMETER | An instrument used to measure wind speed. |
| WIND-CHILL FACTOR | Increased cooling caused by the wind. |
| LOCAL WIND | Winds that blow over short distances. |
| SEA BREEZE | The flow of air from an ocean or lake to the land. |
| LAND BREEZE | The flow of air from land to a body of water. |
| MONSOON | Sea and land breezes over a large region that change direction with the seasons. |
| GLOBAL WINDS | Winds that blow steadily from specific directions over long distances. |
| CORIOLIS EFFECT | The way Earth's rotation makes winds in the Northern Hemisphere curve to the right and winds in the Southern Hemisphere curve to the left. |
| JET STREAM | Bands of high-speed winds about 10 kilometers above Earth's surface. |
| 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. |
| HUMIDITY | A measure of the amount of water vapor in the air. |
| RELATIVE HUMIDITY | The percentage of water vapor in the air compared to the maximum amount the air can hold at that temperature. |
| PSYCHROMETER | An instrument used to measure relative humidity, consisting of a wet-bulb thermometer and a dry-bulb thermometer. |
| CONDENSATION | The process by which a gas, such as water vapor, changes to a liquid, such as water. |
| DEW POINT | The temperature at which condensation begins. |
| 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. |
| LATITUDE | The distance north or south from the equator, measured in degrees |