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108 Cards in this Set
- Front
- Back
What are the 5 layers of the earth atmosphere? |
Troposphere, stratosphere, mesosphere, thermosphere, exosphere |
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What is the lowest layer of the earths atmosphere? |
Troposphere |
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What is the transition boundary between the troposphere and the stratosphere? |
Tropopause |
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What layer of atmosphere extends from the tropopause up to 31 miles above the earths surface? |
Stratosphere |
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The stratosphere is a stable layer devoid of _________ weather. |
Significant |
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In the troposphere a increase in temperature with altitude is abnormal and defined as ___________. |
Inversion |
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The _______ layer of the early atmosphere contains almost all clouds and precipitation, air pressure and density decrease with altitude, and temperature generally decrease with altitude. |
Troposphere |
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A hypothetical vertical distribution of the atmospheric temperature, pressure, and density, which by international agreement is considered to be representative of the atmosphere for pressure-altimeter calibrations and other purposes. |
Standard atmosphere |
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Standard atmosphere is used for what four purposes: |
Pressure altimeter calibrations, aircraft performance calculations, aircraft design, weather-related processes |
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Relatively strong winds concentrated within a narrow, horizontal band in the upper tropopause: |
Jet stream |
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Two commonly identified jet streams: |
Polar jet stream, subtropical jet stream |
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Which direction does the jet stream flow? |
West to east |
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When are jet steams the strongest and why? |
Jet steams are associated with boundaries between hot and cold air, these boundaries are most pronounced during the winter and they are the strongest. |
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Jet streams often produce what kind of turbulence? |
Clear Air Turbulence |
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Which layer of the atmosphere contains most all clouds and precipitation? A. Troposphere B. Stratosphere C. Mesosphere |
A. Troposphere |
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Which layer of the atmosphere is stable and generally devoid of significant weather? A. Troposphere B. Stratosphere C. Tropopause |
B. Stratosphere |
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What is the value of sea level pressure on the standard atmosphere? A. 29.92 hectolascals B. 29.92 inches of mercury C. 1013.2 inches of mercury |
B. 29.92 inches of mercury |
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Which two jet streams are commonly identified? A. Arctic and tropical B. Hot and cold C. Polar and subtropical |
C. Polar and subtropical |
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What is water vapor? |
Water in the invisible gaseous form. |
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What is evaporation? |
The change of liquid water to water vapor |
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What is subliminal ion? |
Change of ice to water vapor |
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____________ is the raw material for clouds and precipitation. |
Water vapor |
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__________ is a measure of the hotness or coldness of the air. |
Temperature |
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The airs capacity to hold water vapor is directly related to its __________. |
Temperature |
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The maximum possible quantity of water vapor that a parcel of air can hold at any given temperature and pressure: |
Saturation |
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Saturation means an air parcel contains all the ______ _______ it can hold. |
Water vapor |
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Unsaturated means the parcel of air has the: |
Capacity to hold more water vapor |
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The temperature to which a given parcel of air must be cooled at constant pressure and constant water-vapor content in order for saturation to occur: |
Dew point |
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The ratio, usually expressed as a percentage, of water vapor actually in the air compared to the amount of water vapor the air could hold at a particular temperature and pressure: |
relative humidity |
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______ _________ does not indicate the actual water vapor content of the air, but rather how close he air is to saturation. |
Relative humidity |
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The difference between air temperature and dew point temperature is called the "_____" |
Spread |
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When the temperature-dew point spread decreases, relative humidity _________. |
Increases |
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When the temperature-dew point spread decreases to zero, the air becomes saturated, and condensation will form ____ or ____. |
Dew; fog |
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The change of water vapor to liquid water: |
Condensation |
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What is the raw material for clouds and precipitation? A. Evaporation B. Dew point C. Water vapor |
C. water vapor |
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A parcel of air that has the capacity to hold more water vapor is ________. A. Saturated B. Unsaturated C. Evaporated |
B. Unsaturated |
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When the _________ decreases to zero, the air becomes ________, and condensation will for dew, fog, or clouds. A. Dew point ; saturated B. Temperature-dew point spread ; saturated C. Condensation ; unsaturated |
B. Temperature-dew point spread, saturated |
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A visible mass of tiny water vapor droplets and/or ice particles in the atmosphere above the earths surface. |
Cloud |
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________ are formed when air is cooled to its dew point and becomes saturated. |
Clouds |
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What is cloud formation? |
When a parcel of rising air expands and cools as pressure decreases with altitude. |
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When a cloud forms what happens to the temperature-dew point spread? |
It decreases |
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What happens in cloud dissipation? |
A parcel of sinking air warms as it encounters increasing pressure and is compressed. |
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What happens to the temperature-dew point spread during cloud dissipation? |
It increases |
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High level clouds which form above 20,000 ft, usually composed of ice crystals, typically thin and white in appearance, contains no significant icing: |
Cirriform cloud |
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Clouds that resemble white fluffy cotton balls or heaps, indicates upward vertical motion or thermal uplift of air, tops can reach over 60,000 ft, may produce icing, turbulence, and other hazards: |
Cumuliform cloud |
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Clouds consisting of featureless low layer that can cover sky, often produces widespread IFR weather, little or no turbulence, but can produce icing: |
Stratiform |
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What is the name for a Stratiform cloud from which rain is falling? |
Nimbostratus |
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Cumuliform clouds that produce precipitation are called? |
Cumulonimbus |
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A parcel of ______ air expands and cools as pressure decreases with height. A. Rising B. Sinking C. Stationary |
A. Rising |
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Which cloud form often produces widespread IFR weather? A. Corridors B. Stratiform C. Cumuliform |
B. Stratiform |
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A motion relative to the surface of the Earth |
Wind |
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A maximum of atmospheric pressure on a surface weather chart; also known as anti-cyclone. |
High weather effects |
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Air flow around high ______ in a _________ motion and sinks. |
Diverges ; clockwise |
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A minimum of atmospheric pressure on a surface weather chart; also known as a cyclone. |
Low weather effects |
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Air flow around low ________ in a _____________ motion and rises. |
Converges ; counterclockwise |
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Air flow around a low _______ in a counter clockwise motion and _______ causing the air to cool and eventually condense into the clouds and precipitation. A. Diverges ; rises B. Converges ; sinks C. Converges ; rises |
C. Converges ; rises |
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A large body of air that has similar horizontal temperature and moisture characteristics. |
Air mass |
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Region where air masses originate and acquire their properties of temperature and moisture. These properties are acquired by prolonged contact (days to weeks) with the underlying surface. |
Air mass source region |
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What are the three temperature properties of an air mass? |
Arctic (A) deep cold air mass develops mostly in winter over ice and snow. Polar (P)relatively shallow cool to cold air mass which develops over high latitudes. Tropical (T) warm to hot air mass which develops over low latitudes. |
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What are the two moisture properties of an air mass? |
Continental (c) dry air mass over land, Maritime (m) moist air mass over water |
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Continental Arctic (cA) classification means? |
Cold, dry |
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Continental Polar (cP) |
Cold, dry |
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Continental Tropical (cT) means? |
Hot, dry |
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Maritime Polar (mP) means? |
Cool, moist |
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Maritime Tropical (mT) means? |
Warm, moist |
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Cold air mass moving over a warm surface often produces unstable air associated with what three things? |
Turbulence, good visibility(outside of clouds), cumuliform clouds and showers |
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Warm air mass moving over a cold surface often produces stable air associated with what three things? |
Smooth, poor visibility, Stratiform clouds, fog, and drizzle |
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A boundary or transition zone between two air masses of different density, and thus, (usually) of different temperature. |
Front |
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A front that moves in such a way that colder air replaces warmer air: |
Cold Front |
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A front that moves in such a way that warmer air replaces colder air: |
Warm Front |
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A front which is stationary or nearly so: |
Stationary Front |
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A composite of two fronts as a cold front overtakes a warm front of stationary front: |
Occluded Front |
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______ fronts have a steep slope and air is forced upward abruptly. |
Cold |
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______ fronts typically have a gentle slope so the air rising along the frontal surface is gradual. |
Warm |
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Narrow bands of cumulus clouds, showers, and thunderstorms along or just ahead of the front if the rising air is unstable, good visibility and turbulence: All associated with what kind of front? |
Cold Front |
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Development of widespread layered or stratiform cloudiness and precipitation along and ahead of the front if the riding air is stable, poor visibility, smooth air and steady precipitation are all associated with what kind on front? |
Warm Front |
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_____ fronts typically move faster than _____ fronts so in time they "catch up" to warm fronts. |
Cold ; Warm |
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When warm and cold fronts merge ________ fronts from. |
occluded |
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Cold air undercuts the retreating cold air mass associated with the warm front, further lifting the already riding warm air is what kind of front? |
occluded |
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________ front is a boundary between two different air masses, neither of which is strong enough to replace the other. |
Stationary |
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A Maritime Tropical (mT) are mass is _______ and _______. A. warm ; moist B. Warm ; dry C. cold ; dry |
A. warm ; moist |
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A ________ air mass moving over a _________ surface often produces unstable air associated with turbulence, good visibility, cumuliform clouds. A. hot ;cool B. warm ; cold c. cold ; warm |
C. cold ; warm |
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Which front moves in such a way that warmer air replaces colder air? A. Cold front C. Stationary front |
B. Warm front |
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What type of front has a steep slope which often leads to a narrow band of showers and thunderstorms if the rising air is unstable? A. Cold front B. Warm front C. Cool front |
A. Cold front |
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Any of the forms of water particles, whether liquid or solid, that fall from the atmosphere and reach the ground. |
Precipitation |
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Precipitation requires the three following ingredients: |
Water Vapor, Lift, and Growth Process |
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A __________ that allows water particles to grow large and heavy enough to fall as precipitation. |
Growth Process |
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Winds transport __________ inland from the Atlantic and Pacific Oceans, Gulf of Mexico, and the Great Lakes. |
Water Vapor |
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Precipitation of snow crystals, mostly branched in the form of six-pointed stars. |
Snow (SN) |
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_____ occurs when the temperature remains below freezing throughout the entire depth of the atmosphere. |
Snow
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Precipitation of transparent of translucent pellets of ice, which are round or irregular, rarely conical, and which have a diameter of 0.2 inch (5mm), or less. Sometimes called "sleet" |
Ice Pellets (PL) |
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When there is a shallow layer aloft with above freezing temperatures, with a deep layer of below freezing air based at the surface, what occurs? |
Ice Pellets (PL) |
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As precipitation re-enters air that is below freezing, it re-freezes into ________. |
Ice pellets (PL) |
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Rain that freezes on contact with the ground or exposed objects. |
Freezing Rain (FZRA) |
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___________ occurs when there is a deep layer aloft above freezing temperatures, with a shallow layer of below freezing air at the surface. |
Freezing Rain (FZRA) |
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Precipitation, either in the form of drops larger than 0.02 inch (0.5mm), or smaller drops, which in contrast to drizzle, are widely separated. |
Rain (RA)
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_____ occurs when there is a deep layer of above freezing air based at the surface. |
Rain (RA) |
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The three necessary ingredients for precipitation formation are ________, lift, and a growth process. A. water vapor B. unstable air C. warm air |
A. Water Vapor |
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Which precipitation type occurs when there is a deep layer aloft with above freezing temperatures, with a shallow layer of below freezing air at the surface? A. Snow B. Ice Pellets C. Freezing Rain |
C. Freezing Rain |
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Federal agency under the Department of Commerce's National Oceanic and Atmospheric Administration (NOAA). |
National Weather Service (NWS) |
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There are how many weather forecast offices in the US? |
122 |
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The NWS offices issue several aviation weather products. There are four: |
AIRMETS, SIGMETS, CONVECTIVE SIGMETS, TAFs |
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What does CWSU stand for?
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Center Weather Service Units |
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Where are Center Weather Service Units located? |
In every ARTCC |
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What do CWSUs provide? |
Meteorological consultation, forecast. |
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CWSUs give advice to ARTCCs and other FAA facilities regarding weather impact on their: (3 things) |
Missions, Equipment outages and repairs, Staffing |
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CWSUs issue what two things? |
Center Weather Advisories (CWAs), Meteorological Impact Statements (MISs) |
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What NWS entity provides consultation, forecast, and advice to Air Route Traffic Control Centers (ARTCCs) regarding weather impacts? B. Weather Forecast Office (WFO) C. Center Weather Service Unit (CWSU) |
C. Center Weather Service Unit (CWSU) |