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171 Cards in this Set
- Front
- Back
- 3rd side (hint)
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WEATHER DEF?
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CURRENT STATE OF THE ATMOSPHERE
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CLIMATE DEF?
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30YR COLLECTIVE STATE OF THE ATMOSPHERE
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METEOROLOGY DEF?
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STURDY OF THE ATMOSPHERE
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ATMOSPHERE DEF?
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LAYERS OF GASES THAT SURROUND THE EARTH'S SURFACE AND ENVELOPE EARTH'S ATMOSPHERE.
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5 PRINCIPLE LAYERS OF THE EARTH'S ATMOSPHERE?
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TROPOSPHERE, STRATOSPHERE, MESOSPHERE, THERMOSPHERE,
EXOSPHERE |
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TROPOSPHERE FACTS
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80% OF ATMOSPHERIC MASS
MOST OF OUR WEATHER OCCURS 10-12MILES INTO ATMOS. |
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HIST: ARISTOTLE
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340 B.C.
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1593(GALILEO)
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THERMOMETER
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1643(TARRICELLI)
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BAROMETER
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1664(DaVINCI/ FOLLI)
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HYGROMETER
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1843(COMMUNICATION)
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TELEGRAPH
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1846
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4 CUP ANEMOMETOR
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1870
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SIGNAL CORPS/ DEPT OF WAR
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1880'S
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SCIENTIST TRIED TO PREDICT TORNADOES
50/YR IN THE U.S. |
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1891
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CIVIL WAR BUREAU
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1920
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AIR MASS THEORY
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1936
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MISSISSIPPI TORNADOES
2 DEADLIEST IN U.S. HISTORY |
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1957
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WEATHER RADAR
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1960
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WEATHER AND SATELLITE DEPLOYMENT
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1974
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TORNADO OUTBREAK
WORST IN HIST. |
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1980
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DOPPLER RADAR
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8 ELEMENTS OF WEATHER
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AIR TEMPERATURE, WIND SPEED, HUMIDITY, CLOUDS, PRECIPITATION, ATMOSPHERIC PRESSURE, VISIBILITY, WIND DIRECTION
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AIR TEMPERATURE
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DEGREE OF HOTNESS OR COLDNESS OF THE AIR
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AIR TEMP. DECREASES WITH HEIGHT (LAPSE RATE)
BECAUSE THE SUN HEATS THE EARTH'S SURFACE WHICH THEN HEATS THE THE AIR ABOVE IT. |
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ATMOSPHERIC PRESSURE
1013.25 MILLIBARS IS STANDARD AT SEA LEVEL |
ATMOS. PRESSURE and DENSITY DECREASES WITH HEIGHT
(rapidly at first then slows down) |
REPRESENTS MASS OF AIR ABOVE THAT LEVEL.
DIVIDED INTO LAYERS ACCORDING TO GAS MAKE-UP, TEMP, OR ELECTRICAL PROPERTIES OZONE-MAIN COMPONENT OF SMOG STRATOSPHERE- PROTECTS US FROM SUN'S RAYS |
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HUMIDITY
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A MEASURE OF WATER VAPOR IN THE AIR
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WIND DIRECTION/SPEED
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HORIZONTAL MOVEMENT OF AIR. EX: THE WIND IS GOING NORTH TO SOUTH, THUS: NORTHERLY WIND.
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TOOLS:
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SATELLITES, RADARS, ATMOSPHERIC PROFILERS, RAWINSONDES, SURFACE WEATHER OBSERVATIONS, AIRCRAFT, LIGHTNING DETECTION NETWORKS, BUOYS, HUMAN OBSERVATION NETWORKS
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TYPES OF SATELLITES
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GEOSTATIONARY: 36KM, ROTATES ALONG THE EQUATOR AT THE SAME SPEED AS THE EARTH.
POLAR ORBITING: ORBIT'S MERIDIANS. |
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TYPES OF RADARS
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INFRARED, REFLECTIVE, WATER-VAPOR
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ISOBAR TYPES
Lines of equal... |
ISOTHERM,
ISOHYET, ISALLOBAR, ISOTROTH, ISOTACH, |
THERM: Temperature
HYET: Rainfall amounts BAR: Pressure change TROTH: Dew point temperature TACH: windspeed |
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ATMOSPHERIC TEMPERATURE INVERSION
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Temp. DECREASES w/ HEIGHT in theory, BUT because levels of the atmosphere also retain heat, then TEMP. may INCREASE w/ HEIGHT.
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MESOSPHERE:
THERMOSPHERE: |
REPRESENTS COLDEST PART OF OUR ATMOS.
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WARMEST PART OF THE ATMOSPHERE
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IONOSPHERE:
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MAJOR ROLE IN RADIO COMM.
THE D REGION DISAPPEARS AT NIGHT THUS AM STATIONS ARE HEARD BETTER FROM DISTANCE. |
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7 CAUSES OF WEATHER
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-SUN'S HEATING VARIES OVER EARTH'S SURFACE
-DIFFERENCES IN AIR TEMP. OVER EARTH'S SURFACE CAUSES WIND -ROTATION OF THE EARTH'S SURFACE DESTROYS WIND PATTERNS: TWISTING=SPIRALS=H & L PRESSURE -LESS MOISTURE EXISTS W/COLD AIR= PRECIPITATION IS CAUSE BY COOLING THE AIR -the PROCESS of DECREASING air pressure causes TEMP to drop. (vise versa) -CLOUDS/PRECIP. caused by rising air (lows) CLEAR SKIES caused by sinking air (highs) |
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HEAT BUDGET (100% incoming rays):
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-6% scattered by atmos.
-19% absorbed by atmos. clouds. -20% reflected by atmos. clouds. -51% absorbed by Earth. --4% reflected by Earth. |
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Ways that we transfer energy?
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-Convection: vertical transfer of heat
-Conduction: transfer of heat from one substance to another. -Advection: horizontal transfer of heat. -Radiation: short waves vs. long waves. |
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LATENT HEAT
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ENERGY REQUIRED TO CHANGE SUBSTANCE.
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SCATTERING
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Dust and other particles redirect radiation resulting in light/ blue sky.
RALEIGH: short-wave scattering MEI: lower levels of atmos. pollen, dust < molce clouds. |
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ALBEDO
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-Total fraction of the radiation that is reflected by a given surface.
-Varies place-to-place/ time-to-time. Factors: Cloud cover, angle, surface. |
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Specific albedo values
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fresh snow: 80-85%
thick clouds: 70-80% water: 50-80% old dirty snow: 50-60% thin clouds: 25-50% sand surfaces: 20-30% grassy areas: 20-25% dry earth: 15-25% wet earth: 10% forested area: 5-10% water overhead: 3-5% |
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Latent heat ABSORBED UP
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-Melting
-Evaporation -Sublimation |
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Latent heat RELEASED DOWN
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-Condensation
-Deposition -Freezing |
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Short wave radiation:
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Solar radiation.
36 deg. or less-> more (SW) radiation is received than lost |
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Long wave radiation:
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Terrestrial radiation
36 deg. or more -> more (LW) radiation is received than lost |
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Ocean currents are driven by...
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Earth's atmosphere/oceans help transfer warmer currents northward; colder air southward
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30-50 deg.
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where most heat transfer occurs/ areas of stormy weather
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Atmosphere composition
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nitrogen and oxygen
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Atmospheric Greenhouse Effect
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Transmission of shortwave radiation by the atmosphere coupled with selective absorption of long wave radiation.
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Absorption and Emission
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Radiates more energy than it absorbs with will turn colder (vise versa)
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Black Body Objects
(not black in color) |
Perfect absorb-er/ emitter:
Ex: sun and earth |
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Radiated Equilibrium Temperature:
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Earth's RET should be 0F/-18C
but Earth's atmos is not black body, thus... RET: 59F/15C |
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Thermometers:
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much better absorbers of heat thus should be:
-away from direct sunlight -5ft above ground -well ventilated -away from radiating surface -ideal--5ft above covered grassy area |
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Temp scales:
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Fahrenheit-U.S.
Celsius- World Wide Kelvin- scientific formulas |
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Fahrenheit:
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Zero point = 32F deg.
Boiling point = 212F deg. +5C=+9F 0C=32F 5C=41F |
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Celsius:
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Zero point = 0C deg
Boiling point = 100C deg C->F C x 1.8 + 32 = F C->K C + 273 = K |
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Kelvin:
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Zero point = 273K (freezing point of water)
Boiling point = 373K K->C K - 273 = C |
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Temp. Controls?
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Radiation is primary
1. Differential heating of land/water 2. Ocean Currents 3. Elevations 4. Latitude and Geographic position |
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Temp. Data Uses?
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Gathered over numerous stations
-hourly -max @ min -high/low -HDD/CDD -Daily/Monthly/Annual avg. temps/ranges |
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Heating/ Cooling Degree Days
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-evaluates energy demands and consumption target avg. 65F/18.3C
-(High + Low)/2 = AVG --AVG > 65F; difference = CDD --AVG < 65F; difference = HDD |
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Heat Stress index factors?
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Temperature and Humidity
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Wind Chill factors?
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Temperature and Wind Speed
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What is the most important element when considering Atmospheric Moisture/ Temp.
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Water Vapor
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Hydro-logic cycle?
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Sublimation: Solid >>> Gas
-Melting: Solid > Liquid -Evaporation: Liquid > Gas Deposition: Gas >>> Solid -Condensation: Gas > Liquid -Freezing: Liquid > Solid |
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Humidity? Specific Type?
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-method of specifying amount of water vapor in the air
Relative Humidity |
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HDD/CDD seasons?
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HDD = January 1 through December 31
CDD = July 1 though June 30 |
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Relative Humidity?
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Ratio(%) of air's actual water vapor COMPARED to water vapor required for saturation at a given temp.
-affected by temp. wind movement(horizontal/vertical) *highest at sunrise, lowest at sunset (opposite temp.) |
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Vernal Equinox
Summer Solstice Autumnal Equinox Winter Solstice |
-March 20 spring/ equal days/nights
-June 21 summer/longer days northern hemp. -September 22 fall/ equal days/nights -December 21 longer nights |
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Dew Point Temp.
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Temp. which air would have to be cooled to reach saturation. Dew Pt. always less than or equal to Temp.
*the lower the DEW PT the less the moisture(vise versa) |
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Air & Dew point temp. closer together RH?
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Higher
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Air & Dew point temp. further apart RH?
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Lower
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Atmospheric Instability/Stability?
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dependent on how fast warm parcels of air rise compared to surrounding air
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Adiabatic
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parcels of a expand/cools, compresses/warms with no interchange of heat of heat with its outside environment.
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Adiabatic rate in UNSATURATED air?
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5.5F/1000ft or 10C/1000m
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Adiabatic rate in SATURATED air?
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3.3F/1000ft or 6C/1000m
(effective once clouds are present) |
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describe a stable environment...
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surface air cools as air aloft warms
air in parcel compresses and warms |
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describe an unstable environment...
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surface air warms as air aloft cools
air in parcel cools and expands |
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cooling the surface air may be due to...
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-nighttime radiation cooling the surface
-influx of cold wind -air moving over a cold surface |
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warming of the surface air may be due to...
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-daytime solar heating of the surface
-influx of warm wind -air moving over warm surface |
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most clouds form as a result of...
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air rising, expanding and cooling.
-surface heating -uplift -air convergence -uplift along weather fronts |
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clouds and condensation?
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-RH humidity reaches 100%
-form at the base of condensation level -layered clouds form in stable atmos. -but, CUMULiform clouds tend to form in conditionally unstable atmos. |
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Collision and Coalescence
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In warm clouds (-15C/5F) larger drops fall faster than smaller drops, thus colliding and making a larger drop and falling at a faster rate.
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factors in droplet formations of clouds with sufficient water
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-range of droplet size
-cloud thickness -updraft of the cloud -electrical charge of cloud and droplets |
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Ice-Crystal process (Bergeron)
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Ice crystals and cloud droplets must co-exist in clouds at temps below freezing in "cold clouds". Thus, water droplets are overtaken by ice crystals.
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Precipitation types?
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-Rain
-Snow -Hail |
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High Clouds
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-above 20k feet
-CIRR --Cirrus (Ci) --Cirrocumulus (Cc) --Cirrostratus (Cs) |
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Cirrus (Ci)
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Wispy streamers, mostly ice crystals, supercooled, fair weather, "mares tales", west to east upper level jet stream wind.
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Cirrocumulus (Cc)
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small cumulus puffs, rippled appearance, individual or long rows, instability, "makerel sky", scales of fish.
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Cirrostratus (Cs)
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stratified, thin sheet like, white, cover entire sky, sun/moon can be seen through it, "halo effect", fair weather.
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Middle Clouds
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-6k to 20k feet
-ALTO --Altocumulus (Ac) --Altostratus (As) |
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Altocumulus (Ac)
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Gray, puffy, rolled out in parallel waves, darker base, "rising castles"(castellanus), instability.
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Altostratus (As)
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Gray to Blue-gray, cover entire sky, dull round disks, form in advance of storms, produce widespread cont. precipitation.
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Low Clouds
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-surface to 6.5k feet
-STRAT --Stratus --Stratocumulus (Sc) --Nibostratus (Ns) |
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Stratus (St)
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gray, stratified, light drizzle/snow, fog occurs if close to ground, uniform cloud.
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Stratocumulus (Sc)
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low, lumpy layer, contain more water, larger cumulus puffs(up to fist size), rows, little or no precipitation, white to dark gray.
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Nimbostratus (Ns)
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dark, gray, wet-looking, continuous light/moderate precipitation, harder to identify. NOT: see though, thunder, lightning, hail.
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Clouds of Vertical Extent
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-Cumulus (Cu)
-Cumulonimbus (Cb) |
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Cumulus (Cu)
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detached domes or towers, dense, well defined, FAIR weather, indicate rising air motion,
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Cumulonimbus (Cb)
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Large, towering, precipitating, thunder, lightning, rain, severe storms, blacksmith's anvil.
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Overshooting top?
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strong updraft builds up and bulges up through the storm.
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Dew point?
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water that has condensed onto objects near the ground, when temperature of those objects falls below the dew point temp of the surrounding air.
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What is frozen dew?
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if condensation falls below freezing then it becomes frozen dew.
-when temp falls below freezing after dew has formed. |
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What is frost and how does it form?
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It is a covering of ice crystals produced by Deposition.
when the temp. falls below freezing and an exposed object's temp. falls below dew point/frost point temp. |
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What is precipitation before it hits the ground?
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Vigra
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Drizzle
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Drops that hit the ground from low Status Clouds, low visibility fog, <0.5mm/0.02in
-light <0.01" -moderate <0.01"-0.02" -heavy 0.02" |
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Rain
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precipitation generally from nibostratus/cumulonimbus clouds, 0.02" or greater.
Intensity based on rate of fall: -very light -light 0.10"/hr -moderate 0.11" < 0.30"/hr -heavy 0.30"/hr or more |
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Freezing Rain
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same rates as rain, freezes upon impact and forms glaze
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Freezing Drizzle
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same rates as drizzle, freezes upon impact
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Ice Pellets (graupel or sleet)
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Cold weather precipitation, transparent/translucent pellets < 0.2" bounce when they hit the ground, form from rain droplets or melted snowflakes
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Snow
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cold weather precipitation, white or translucent ice crystals, hexagonal, produced in supercooled clouds, as a result of DEPOSITION in cloud, remains frozen through entire descent. up to 0.8"
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Snow intensity is based on...
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Visibility
-light: 5/8 mile or more -moderate: <5/8 mile -heavy: <5/16 mile |
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Hail
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Precipitation in the form of balls of ice, produced by convective clouds (cumulonimbus), 0.2" or greater,
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Air Pressure
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-weight of air above a given surface
-air pressure ALWAYS decreases with height |
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A short colder, more dense column of air experts the same force as...
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a taller, less dense column of air
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In a warm column of air molecules move...
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faster and spread further apart thus increasing in column height
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Ina cold column of air molecules move...
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slower and closer together, thus shortening column height
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Atmospheric pressure decreases more rapidly in a...
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colder column of air
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Atmospheric pressure decreases more slowly in a...
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warmer column of air
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Warmer air aloft is normally associated with...
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Higher atmos. pressure
thus more stable atmos |
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Colder air aloft is normally associated with...
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Lower atmos. pressure
thus more stable atmos |
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Atmos. pressure decreases, on average...
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1" of mercury every 1000 feet
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Standard atmos. pressure is...
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29.92" mercury or 1013.25 millibars or 14.7 lbs/inch
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High Pressure characteristics
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Air blows around High counterclockwise in northern hemisphere.
Surface Air: Divergence Upper Air: Convergence |
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Low Pressure characteristics
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clockwise in northern hemisphere.
Surface Air: Convergence Upper Air: Divergence |
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Upper air charts. Constant height.
What is the relationship between height and pressure? |
Higher surface height = Higher pressure
Lower surface height = Lower pressure *distance between surface and constant pressure height. |
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Newton's 1st Law?
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an object in motion will remain in motion until so long as no force is exerted on it.
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Newton's 2nd Law?
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Force = mass x acceleration
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Newton's 3rd Law?
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For every action, there is an equal and opposite reaction
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Atmospheric forces that causes the wind to blow?
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-Pressure gradient forces High vs Low pressure
-Coriolis force: due to Earth's rotation -Friction of Earth's surfaces |
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Coriolis forces can be altered by...
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-rotation of the Earth
-Latitude -object's speed are affected by the Coriolis force |
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Geostrophic wind?
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wind blowing in a straight path, parallel to the isobar/ constant contour lines, at a constant speed.
-Buys-Ballot Law: back to wind; low on left, high on right. -exact balance of pressure gradient force and coriolis force -found in upper level wind flow |
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Hydrostastic Balance?
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balance between vertical pressure gradient force and Earth's gravity keeps the Earth's atmosphere in place.
-Thunderstorms cause astmos. imbalance |
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How is wind measured?
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-Direction
-Speed: 2min avg (sustained) -Gusty-ness: instantaneous speed peak w/in last 10 min -Prevailing wind -Wind rose |
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Wind Shear?
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rapid change in wind direction and or speed in a small atmos. area.
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Micro-scale
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small tornadoes
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Meso-scale
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large city/state size weather analysis
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Synoptic scale
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Weather map scale
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Global scale
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long waves in the westerlies
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Single cell atmos. motion
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-Created by George Hadley
-High pressure at the poles -One big circulation cell -Weather systems move in from the west due to Earth's rotation counterclockwise -too simple |
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6 Cell Atmos. Circulation system
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0N-north pole
-POLAR CELL (polar easterlies) 60N-polar front HADLEY CELL (westerlies) 30N-horse latitudes / subtropical jet stream FERREL CELL (northeast trades) 0 (equator) InterTropical Convergence Zone. Doldrums. FERREL CELL (southeast trades) 30S-horse latitudes / subtropical jet stream HADLEY CELL (westerlies) 60S-polar front POLAR CELL (polar easterlies) 0S-south pole |
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In the summer the polar jest stream, in relation to the U.S., is where?
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located across the northern states and Canada, but then moves south during the winter months.
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Jet streams?
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strong mainly upper level steering wind.
-Polar Jet Stream (moves cold air south) -Subtropical Jet Stream (moves warm moist air north) |
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What is upwelling?
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when surface wind blows up-shore and brings cold, nutrient rich water up to the surface.
-ideal for fishing -happens on a larger scale during La Nina |
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La Nina?
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-Colder than average equatorial
-west of South America to Eastern Australia -Does not increase the subtropical jet -fishermen are happy |
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El Nino?
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Warmer than average equatorial
-weaker trade winds -weaker upwelling -bad for fishing -wet climate with more rain |
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Sea Breeze (day)
Land Breeze (night) |
Day: Higher pressure over water; Lower pressure over land. Breeze from Sea to Land.
Night: Lower pressure over water, higher pressure over land. Breeze from Land to Sea. |
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Surface and heat retention:
Water vs. Land |
Water retains more heat. During the day land is heated and reflects more heat(low pressure) back up. At night, water releases heat slower than land (lower pressure).
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During the day the sun warms the surface so...
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warmer air rises during the day. At night, cooler air radiates onto surfaces, the higher the surface the cooler, the lower the surface the "warmer".
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Valley Breeze(day)
Mountain Breeze(night) |
Day: Lower pressure over valley, warmer air is rises/pushes up the mountain. Breeze into valley.
Night: Higher pressure at mountain tops, cooler air sinks/pushes down into the valley. Breeze towards the mountain tops. |
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What is a monsoon? Where do they occur? Seasons?
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-A seasonal wind shift
-India/SE Asia --SW USA (summer thermal low) -Winter monsoon (high pressure on shore to low pressure off shore) --Summer (high pressure off shore to low pressure on shore) |
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What is the relationship between High and Low pressure in terms of wind direction / breeze flow?
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Flows from High to Low
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What are Thermal Lows?
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low pressure circulation created by changes in air temp.
Ex: strong day-time heating over southwestern USA during summer months = summer monsoon over Arizona |
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What is Katabatic wind?
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-COLDER, down sloping wind due to gravity.
-can be destructive -Greenland/Antartica -referred to as "Mistral" in the Alps (Eur.) |
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What is Chinook wind?
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-WARMER, down sloping wind
-Eastern slopes of the Rockies -Leeward side --Ex:Santa Ana winds in fall |
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Dust devils occur because of...
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intense heating at the surface
-Ex: Haboob (north africa/india) --other local wind ---Eddie wind shield |
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What is an Air Mass? What is it characterized by?
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a mass of air, categorized by temperature and humidity
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Anti-Cyclone
Cyclone |
-clockwise
--High pressure surface (convergent) with Low pressure upper (divergent) -counterclockwise --Low pressure surface (convergent) with High pressure upper (divergent) |
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Extra-tropical Frontal cyclone has what kind of core?
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cold core
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Tropical frontal cyclone has what kind of core?
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warm core
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Source region: Land - continental (cP/cT)
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continental Polar: Cold, dry stable
continental Tropical: Hot, dry, stable air aloft; unstable surface air |
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Source region: Water - maritime (mP/mT)
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maritime Polar: Cool, moist, unstable
maritime Tropical: Warm, moist; usually unstable |
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what is lake-effect snow?
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when the cold, dry air mass moves over relatively warm body of water, such as Great Lakes, heavy snow showers.
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thunderstorms develop where?
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where the cold front meets the maritime tropical air being brought north. (more lift)
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Frontolysis vs Frontogenesis
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kills front vs makes front
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Cold front
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cold air actively advances onto regions previously occupied by warm air
-drawn in blue w/ triangles pointing in direction of movement -steep slope (1:50) -great for cumulonimbus |
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Warm front
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warm air occupies the position previously held by cold air
-drawn in red w/ half circles pointing in the direction of movement -more gentle slope (1:50) |
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Stationary front
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usually upper level winds are parallel to the surface frontal boundary. anything can happen from no clouds to thunderstorms
--flash floods occur. "training" |
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Occluded front
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when a cold front over takes a warmer front in the vicinity of a surface low. not common in Tx.
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fronts are normally found in what kind of pressure areas?
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zones of low pressure
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Veering wind?
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shifts clockwise
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Backing wind?
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shifts counterclockwise
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Dry line?
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surface boundary that separates warm and hot air masses
-NOT A FRONT -found in US plains states, Tx northward -warm dry air (cT) collides with warm moist air (mT), thus moist air will rise over hot dry air. --thunderstorms may occur |
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