Weather Flashcards
atmoshperic circulation is caused by:
uneven heating
Basic elements of weather
-atmoshpere
-air masses
-temperature (warm or cold)
-pressure
-wind (a vector with speed and direction)
-moisture (or humidity)
-clouds
-precipitation
Three Cell Theory
-uneven heating from the sun
-tilt of the earth
-coriolis force
lifting air
low pressure
sinking air
high pressure
turns non-steerable objects to the right in the northern hemisphere
Coriolis effect
Natural air = ________+__________+_________
dry air
condensation nuclei
water vapor
Atmoshpere is made up of ___% oxygen
20.95%
Atmosphere is made of ___% nitrogen
78.08%
Atmosphere is made of ___% Trace Gases
.04
Atmosphere is composed of ___% argon
.93%
5 air masses affecting United States the most
-Siberian High
-North American High
-Icelandic High
-Pineapple Express
-Bermuda High
standard temperature lapse rate
2 degrees
OLR
observed lapse rate
stable atmosphere
an atmosphere that is changing less than 1.5 degrees per 1000 ft
unstable atmosphere
3 degrees or greater OLR
four methods of heat transfer
-radiation
-conduction
-convection
-advection
insolation
comes from the sun to the earth
types of temperature inversions
-radiation (or nocturnal)
-frontal
which fronts have a temperature inversion
all of them
all fronts are _____ pressures
low
the rate at which air will accelerate depends on rate at which pressure changes with distance
Pressure gradient force
causes the wind to blow
pressure gradient force
the closer the isobars are spaced, the _____ the wind
faster
we call closely spaced isobars:
strong or steep pressure gradient
We call widely spaced isobars:
weak or flat pressure gradient
above 2000 feet, the wind tends to ________
parallels the isobars
high to low _________
lookout below
Low to high _____
nothing but sky
three states of moisture: visible and invisible
-gas/vapor (invisible)
-liquid (visible)
-solid (visible)
most common way clouds are formed
adiabatic process
when the temperature of a gas is changed without the addition or deletion of heat energy
adiabatic process
an altitude to which the air must be lifted for condensation to take place. Clouds will form at this altitude. Temperature and dew point are the same.
level of condensation or lifted condensation level
a boundary between air masses of different density
front
the name of the front comes from what happens ___________
after the front passes
four requirements for front to be identified
-Temperature
-Dew point
-Pressure - “fall then rise”
-Wind shift - approx. 90deg, will need drift correction to the right (wind speed and direction will change across a boundary)
wind is always recorded _________ its direction
from
steep slope
1:80 average
trailing edge of a cold air
warm front
warm front slope
shallow
warm fronts affect _______ area than a cold front
more
atmospheric layers
(starting from earth)
-troposphere
-stratosphere
-mesosphere
-thermosphere
-exosphere
air ____ and _______ to the upper latitudes
air ____and_______to the lower latitudes
cools and descends
warm air _____ and moves _________ the poles
rises
toward
air mass classification: water vapor content:
-c_________(________)
-m_________(_________)
continental air mass (dry air)
maritime air mass (moist air)
Temperature: (by Latitudes of origin)
-A= arctic air mass (70-90 deg)
P=Polar air mass (40-60 deg)
T= Tropical air mass (10-30 deg)
E = Equatorial air mass (0-10 deg)
Temperature is a measurement of _________ and describes the degreee of ____________ activity.
heat energy
molecular
Temperature Characteristics:
-Standard Day: _____
-Warmest temperatures near_____
-Decreases with _______
-Standard _________
-OLR- _________
-15 deg C
-ground
-altitude
-lapse rate
-observed lapse rate
observed lapse rate is the _____________ lapse rate, not the ________________
actual
averaged out
Radiation (__________) Inversion
-Best conditions:____________
nocturnal
clear and cool night
______________ clouds redirect the heat back to the ground
overcast
Masses of air meet- the _______ mass is less dense and _____________ while the ___________________ air settles to the ground.
warmer
lifts
colder
Standard day pressure
Hg
hP/mb
29.92”
1013.2
Pressure Systems- High (___________)
Anticyclone
General Weather High Pressure
-sinking of air near center
-divergence
-light to moderate wind
-usually no turbulence
-visibilitygood, except for early morning fog or haze
-flying conditions- good
As high pressure air sinks, it tends to _______________________ the air, _____ the moisure, have ____ turbulence, and _______ wing
dry out
decrease
less
less
Pressure Systems Low ( ____________)
Cyclone
General Weather Low Pressure
-lifting near center of low
-convergence
-moderate to strong wind
-turbulence
-visibility limited by clouds, fog, precip
-ALL FRONTS ARE LOW PRESSURE
-flight conditions-poor
water is in a constant state of transformation called the ___________________
hydrologic cycle
fog resulting from surface cooling
advection
FOG
-warm, moist air flowing over a cooler surface
-deepens with wind between 3-9 KTS
-can be deep, persistant
advection fog
Fog that results from radiation cooling on clear, calm nights
radiation fog
FOG
-relatively shallow
-light winds
-midnight to sunrise
radiation fog
Types of fog
-radiation
-advection
-precipitation-induced
-upslope
-freezing
-ice
_________ slows dissipation of fog
greenhouse effect/ovc sky
__________prevents fog
greenhous effect/ovc sky
Fog dissipation factors (3)
-heating
-strong wind (except for 2 types of fog)
-greenhouse effect/ovc sky
Fog cooling actions
-radiation
-adiabatic
-conduction
small temparature/dew point spread, abundant condensation nuclei, light surface wind (except for 2 types), and cooling land surfaces with warm air above are all __________________________________
fog formation factors
fog resulting from moist, stable air being lifted by sloping terrain
upslope fog
FOG
-cools adiabatically
-wind greater than 10 KTS
-may cause cap clouds
upslope fog
Fog that results from conditions when supercooled droplets contact freezing surface
freezing frog
FOG
-supercooled droplets remain liquid until contacting freezing surface
-sub-freezing temps
freezing fog
Fog resulting from extremely cold temperatures and deposition
Ice fog
FOG
-tiny ice crystals suspended in air
-temps less than or equal to 30 deg C
-often seen in Arctic/Polar air
Ice Fog
Visible moisture with base below 50ft and no visible downward motion
fog
visibility less than 5/8 sm
fog
visibility greater to or equal to 5/8 sm
mist
FOG flight planning
-consider fog formation at destination
-check weather reports
-pick an alternate airfield
-ask questions
six BASIC elements of weather are the following:
-temperature (warm or cold)
-pressure
-wind
-moisture (or humidity)
-clouds
-precipitation
Condensation nuclei consist of:
dust, smoke, and salt (hygroscopic)
salt particles _____________ water vapor
attract
how do i request a weather brifing
training environment: you will generally fly off of our product set.
-in advanced aircraft: you may occasionally request a DD 175-1 for a specialm multi-ship mission
-outside training environment: local weather flight will “provide or arrange for support”
-deployed environment: staff weather officer (SWO)
