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Weather Unit Vocab
All words needed in our Weather Unit
Term | Definition |
---|---|
Atmosphere | A very thin layer of gases that surround a body.(pg 158) |
Air pressure | The measure of the force with which particles in the air push down on a area or surface.(pg 161) |
Troposphere | The lowest layer of earth's atmosphere, has a thickness of about 10-12 km.(pg 162) |
Stratosphere | The second layer of earth's atmosphere, between the troposphere and the mesosphere. This is the layer where planes fly, the ozone layer is positioned, and is about 15-40 km in thickness.(pg 163) |
Mesosphere | The layer of the atmosphere between the stratosphere and the thermosphere. This is the layer that usually destroys meteorites when they come into our atmosphere.(pg 164) |
Ionosphere | The bottom part of the thermosphere. This is where radio signals bounce off of and come back down to earth. |
Exosphere | The very top of the thermosphere going into outer space. This considered the thermosphere until outer space starts. |
Thermosphere | The uppermost layer of the atmosphere. The thermosphere is split into 2 sections, the ionosphere and the exosphere.(pg 164) |
Ozone Layer | The ozone layer is located in the stratosphere and is the reason why the temperature rises with altitude in the stratosphere. The ozone layer absorbs ultraviolet solar radiation, which is why the stratosphere is warmer than the troposphere.(pg 163) |
Greenhouse Effect | The greenhouse effect is the warming of the surface of the earth and the lower parts of the atmosphere. This happens with water vapor, carbon dioxide, and other gases. The gases absorb and re-radiate thermal energy.(pg 166) |
Temperature | A measure of how hot or cold something is; specifically a measure of the average kinetic energy in a object.(pg 172) |
Thermal Energy | The kinetic energy of a substance's atoms(total).(pg 172) |
Thermal Expansion | An increase in the size of a substance in response to an increase in the temperature of a substance.(pg 173) |
Heat | The energy transferred between objects that are different temperature.(pg 174) |
Radiation | The transfer of energy through electromagnetic waves.(pg 176) |
Convection | The movement of matter due to differences in density; the transfer of energy due to the movement of matter.(pg 178) |
Conduction | The transfer of energy as heat through a material.(pg 180) |
Wind | The movement of air caused by differences in air pressure.(pg 186) |
Coriolis Effect | The curving of the path of a moving object from a otherwise straight path due to the Earth's rotation.(pg 187) |
Jet Stream | A narrow band of strong winds that blow in the upper troposphere.(pg 190) |
Local Wind | The movement of air over short distances; occurs in specific areas as a result of certain geographical features.(pg 192) |
Sea Breeze | The colder, denser air over water flows toward land and pushes the air on land upward.(pg 192) |
Land Breeze | At night, cooler air on land causes a higher-pressure zone over the land. So, wind blows from the land toward the water.(pg 192) |
Mountain Breeze | At nightfall the air along the mountain slopes cools and moves down into the valley.(pg 193) |
Valley Breeze | During the day, the sun warms air along the mountain slopes faster than air in the valley's. This uneven heating results in pressure on the mountain tops. This causes air to flow up from the valley.(pg 193) |
Global Wind | The movement air over Earth's surface in patterns worldwide.(pg 188) |
Trade Winds | Winds that blow between 30 degrees latitude and the equator in both hemispheres. Sailor relied on these winds to get from the Americas to Europe.(pg 188) |
Westerlies | Wind that blow between 30 and 60 degrees latitudes in both hemispheres. The rotation of Earth causes these winds to curve east. This winds carry moist air creating rain and snow in the continental US.(pg 188) |
Polar Easterlies | These winds blow between the poles and 60 degrees in both hemispheres. Rotation of Earth make these go west. Carry cold Arctic air over most of teh Us producing snow and freezing weather.(pg 188) |
Doldrums | When trade winds meet at the equator it is calm. There is very little wind. At about 30 degrees latitude air stops moving and sinks.(pg 189) |
Horse Latitudes | When air stops and sinks this creates calm areas. Ships going or are leaving Europe to the Americas would be stalled there sometimes horses were thrown overboard.(pg 189) |
Weather | The short-term state of the atmosphere, including temperature, humidity, precipitation, wind, and visibility.(pg 225) |
Humidity | The amount of water vapor in the air. |
Relative Humidity | The ratio of the amount of water vapor in the air to the amount of water vapor to reach saturation.(pg 225) |
Dew Point | At constant pressure and water vapor content, the temperature at which the rate of condensation equals the rate of evaporation.(pg 225) |
Precipitation | Any form of water that falls to Earth's surface from the clouds.(pg 226) |
Cirrus | Types of clouds that appear feathery or wispy. Their name means "curl of hair." They are made of ice crystals that form when there are strong winds.(pg 227) |
Cumulus | Their name means "heap" or "pile." Usually these clouds form of fair weather but if they keep growing taller, they can produce thunderstorms.(pg 227) |
Stratus | The name means "spread out." Status clouds form flat layers. Low dark stratus clouds can block out the sun.(pg 227) |
Air pressure(density) | The force of air molecules pushing on a area.(pg 161&228) |
High Pressure System | They are areas where air sinks and move outward. The sinking air is denser than the surrounding air.(pg 238-239) |
Low Pressure System | This means the area has lower air pressure than all surrounding areas. Air in low pressure systems come together, or converges and rises.(pg 238-239) |
Air Mass | A air mass is a large volume of air in which temperature and content are nearly the same throughout.(pg 236) |
Front | A front forms a boundary in between air masses. For a front to form, one air mass must run into another.(pg 236) |
Warm Front | These fronts form when a warm air mass follows a retreating cold air mass, The warm air rises over the cold air, and its moisture condenses into clouds.(pg 237) |
Cold Front | This happens when a cold air mass that is moving can quickly push up a warm air mass.(pg 237) |
Stationary Front | This is when there is not enough wind for either a cold air mass or a warm air mass.(pg 237) |
Occulded | To stop, close up, or obstruct an opening.(pg N/A) |
Evaporation | Occurs when a liquid water changes into water vapor. About 90% of the water in the atmosphere, comes from the evaporation of Earth's water. Most water evaporates from Earth's oceans.(pg 96) |
Condensation | The change of the state from a gas to a liquid. If air that contains water vapor is cooled enough condensation occurs.(pg 97) |
Runoff | Streams, rivers, ponds, etc. Basically any water that flows over land are types of runoff. Runoff flows downhill towards oceans, lakes, and marshlands.(pg 98, 106-108, 138, and 368) |