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69 Cards in this Set
- Front
- Back
An equilibrium is reached where the number of water molecules leaving the watersurface (rate of _______ ) is equal to the number of molecules returning to thesurface (rate of _______). |
evaporation, condensation
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The pressure (water content of the air) at thisequilibrium of evaporation and condensation is called the _________ ________ _______ . |
saturation vapor pressure
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“The maximum amount of water that can be held in a given volume of air”(called the saturation vapor pressure) is a function of ___ __________. |
air temperature
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Relative Humidity = |
Actual Vapor Pressure / Saturation Vapor Pressure X 100
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When relative humidity hits one hundred percent, that is the occasion on which we can record the _____ ______ temperature |
dew point |
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______ _____: the decrease of an atmospheric variable with height, thevariable being temperature unless otherwise specified.(Change in temperature with altitude) |
Lapse rate
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What are the two types of lapse rate? |
Environmental lapse rate, Adiabatic lapse rates |
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_______ _______ ______ – which refers to the actual change oftemperature with altitude for the stationary atmosphere (i.e. thetemperature gradient) |
Environmental lapse rate
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______ ______ _____ – which refer to the change in temperature of amass of air as it moves upwards. |
Adiabatic lapse rates
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There are two adiabatic rates: |
Dry adiabatic lapse rate
Moist (wet or saturated) adiabatic lapse rate |
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The __________ ______ _____ , is the negative of the actual change of temperature withaltitude of the stationary atmosphere at a specific time and specific location. |
environmental lapse rate
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Theenvironmental lapse rate at a given place varies from day to day and even during eachday. T or F |
True |
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As an average, the International Civil Aviation Organization (ICAO) defines an _______ _______ ______ (ISA) with a temperature lapse rate of _._°C/1,000 m(3.56 °F or 1.98 °C/1,000 ft) from sea level to __ km (36,090 ft). |
international standard atmosphere, 6.5, 11
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It is helpful to think of adiabatic processes as occurring within an air ____ . |
parcel
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By convention we think ofan air parcel as being a ___ _______ cubic meters in volume. |
few hundred
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The term adiabatic means that no ______ ______ (energy transfer due to a temperature difference)occurs into or out of the parcel. Air has low _______ conductivity, and the bodies of air involved are very large, so transfer of heat by conduction is negligibly small. |
heat transfer, thermal
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It is convenient to ignore mixing of surrounding air with the air parcel. The mixing of surroundingair with the air parcel is known as _________. |
entrainment
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The ____ ______ lapse rate is the negative of the rate at which a rising parcel of dry or unsaturatedair changes ________ with increasing height, under adiabatic conditions. |
dry adiabatic, temperature
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Unsaturated air has lessthan 100% relative humidity (its _______ is higher than its dew point). |
temperature
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When the air is stirred (for instance, by convection), and a parcel of air rises,it ______, because the pressure is lower at higher altitudes. As the air parcel ______, it pushes onthe air around it, doing work; since the parcel does work and gains no heat, it loses _______ ______,and so its temperature decreases at a rate of approximately 10.0 °C per 1,000 m |
expands, internal energy |
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_____ ______ _____ is the altitude at which condensation begins (the temperatureof the rising air parcel reaches the dew point temperature). |
Lifting condensation level
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When an air parcel rises to the lifting condensation level, a critical thing happens. The ______ heat that was absorbed by the water vapor when it was evaporated is ______ upon reaching thelifting condensation level. |
latent, liberate |
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while the air parcel will continue to rise past the lifting condensation level, it will not cool as rapidly as a dry air parcelbecause the ____ ______ of condensation is slowing the rate of adiabatic cooling. |
latent heat |
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It's 5 degrees Celsius in Jan with 80% relative humdity, it's 30 degrees Celsius in July with 80% relative humidity. When does the day feel more humid, where is there a higher saturation rate? |
On the day in July because warmer air can hold more moisture |
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When the air is saturated with water vapor (at its dew point), the _____ _____ lapse rate or ______ _____ lapse rate applies. |
moist adiabatic,saturated adiabatic
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Dry adiabatic rate = __.0 °C per 1,000 m Moist adiabatic rate = __.0 °C per 1,000 m |
10, 5 |
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The reason for the difference between the dry and moist adiabatic lapse rates is that ______ ____ isreleased when water condenses. |
latent heat |
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There are four mechanisms that cause air to rise: |
•Orographic Lifting •Frontal Wedging •Convergence •Localized convective lifting |
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When air is forced over a mountainous barrier, ______ lifting. |
Orographic |
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When warmer, less dense air, is forced over cooler, denser air. |
Frontal Wedging |
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When a pileup of horizontal air flow results in upward movement. |
Convergence |
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When unequal surface heating causes localized pockets ofair to rise because of their buoyancy. |
Localized convective lifting |
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As a parcel rises, it expands and cools (adiabatic). If we compare the air parcelto the surrounding air we can determine its ________ . |
stability
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If the air is cooler (more dense) than the surrounding air, then it is called _______ _____. _____ _____resists vertical movement. |
stable air |
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If the air is warmer (less dense) than the surrounding air, then it is called____ ____. ______ _____ will rise (much like a hot-air balloon). |
Unstable air |
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As dry air rises, itexpands and cools at the____ _____ lapse rate.Thus, it soon cools to thetemperature of thesurrounding air, and it _____ rising. |
dry adiabatic, stops
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As moist air rises, initially itcools at the ____ _____ lapserate. It soon cools to its _____ _____, and clouds form. |
dry adiabatic, dew point
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Air cools more slowly at the____ _____ lapse rate. As aresult, it remains warmer thansurrounding air and continuesto rise for thousands of meters. |
wet adiabatic
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Air stops rising when all_____ has condensed, andthe air again cools at its dryadiabatic rate. |
moisture |
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Warm moist air is_______ because it rises rapidly, forming towering clouds and heavy rain. In addition, air rushes along the ground to replace the rising air, thus generating _____ ______ . |
unstable, surface winds
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Warm dry air is said to be _____ . |
stable
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______ _____ (L., wisp of hair) are high (6,000-15,000 m),wispy clouds composed of ice crystals rather than waterdroplets. High winds aloft blow them out into long, gentlycurved streamers. |
Cirrus clouds
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_______ (L., layer) are horizontally layered, sheet-likeclouds. |
Stratus clouds
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Stratus clouds form when _____________ forms at the sameelevation at which air stops rising, and the clouds spread outinto a broad sheet. |
condensation |
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_______ _______ (L., heap or pile) are fluffy white cloudsthat typically display the flat bottoms and billowy tops. |
Cumulus clouds
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Thebase of a cumulus cloud forms at the altitude at which the rising aircools to its ____ ______ and condensation starts. However, itthis situation, the rising air remains ______ than thesurrounding air and therefore continues to rise, As it rises,more vapor _____, forming the billowing columns. |
dew point, warmer, condenses |
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: sheet-like cloudswith some vertical structure |
stratocummulus
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: refers to clouds thatprecipitate |
nimbo
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: towering rain cloudthat produces intense rain, thunderand lightning |
cumulonimbus
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: stratus cloud fromwhich rain or snow falls
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nimbostratus
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: high stratus clouds |
altostratus
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: cloud that forms very close to the ground.
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Fog |
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: created when warm, moist air from the sea blows onto cooler land surface. |
Advection fog |
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: created when air near the surface cools by heat loss (radiation) at night. |
Radiation fog |
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: created when air is cooled by evaporation from a body of water. |
Evaporation fog |
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: created by rising airmass along a land surface. |
Upslope fog
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When condensation occurs above the ground, particulate matter, known as ________ _______, serve as surfaces for water vapor condensation (microscopic dust, smoke, saltparticles, etc.) |
condensation nuclei |
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If the droplets that form are small, they require a long time to descend and may wellevaporate in the still air during descent.If the droplets coalesce they form large droplets and fall as _____. |
drizzle |
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In many clouds, ice crystals form and grow as more water condenses on the surface. Asthey become large enough they fall and melt on descent, creating ______ . |
rainfall
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If temperatures at the surface are sufficiently low, the ice crystals remain frozen and fall as _____ . |
snow
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If falling ice crystals melt, but fall through a cold layer during descent, they may refreeze and create _____ . The sleet can refreeze on cold surfaces creating _____. |
sleet, gaze
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If turbulent winds exist in the ___ atmosphere, the falling ice crystals are transportedback upward into the cloud, where new layers of ice accumulate as additional vaporcondenses on their surface. The result is ____ (concentric shells of ice). |
hail |
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Temperature ______ are not the common state of the lower atmosphere. Usually, air temperature decreaseswith an increase in altitude in the troposphere |
inversions
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In the mid-______, we often find temperature inversionsdeveloping along the moving ____ edge of a cold air mass that is overtaking warmer air. |
latitudes, front |
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An inversion is also produced whenever _______ from the surface of the earth exceeds the amount of _______ received from the sun, which commonly occurs at night, or during the winter when the angle of the sun is verylow in the sky. |
radiation |
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As snow falls into the layer of air where thetemperature is above freezing, the snowflakes partially melt. As the precipitationreenters the air that is below freezing, theprecipitation will re-freeze into ice pelletsthat bounce off the ground, commonlycalled _____ . |
sleet
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________ ________ will occur if the warm layer inthe atmosphere is deep with only a shallowlayer of below freezing air at the surface. |
Freezing rain
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_____ is frozen precipitation produced by intense thunderstorms. |
Hail |
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Formation of Hail. As the snowflakes fall, liquid water freezes onto them formingice pellets that will continue to grow as more and more droplets are accumulated. Upon reaching the bottom of the cloud, someof the ice pellets are carried by the ______ back up to the top of the storm. |
updraft |