Test Review Flashcards
Dry air
78% nitrogen
21% oxygen
1% other gases
Natural air composition
Water vapor and condensation nuclei
Layer of the atmosphere where weather occurs
Troposphere
3 conditions that affect atmosphere circulation
Uneven heating, Coriolis, tilt of earth
Difference between C and M
Continental and maritime
Occurs over land and other over water
Difference between T and P
Tropical and Polar
Warm vs cold
4 types of heat transfer
Convection
Radiation
Advection
Conduction
How does temp inversión occur.
Increase of temp with altitude
Two types of temp inversion
Radiation and frontal
What would prevent radiation temp inversion from occurring?
Overcast clouds
What is the standard MSL pressure and millibars?
29.92 and 1013.2
How do isobars help show wind speed?
Closer they are the stronger and faster winds are
Low pressure description
Rising lifting pressure, worse weather
High pressure description
Decreasing pressure, better weather
What causes winds to flow across the isobars below 2000 AGL instead of going parralel?
Surface friction
Wind coming in right door
Going to high pressure, better weather
Wind coming from left door
Going into low pressure, worse weather
Evaporation description
Liquid to vapor/gas
Condensation description
Vapor to liquid (a cloud, visible moisture)
Sublimation description
Solid to Gas (dry ice)
Deposition description
Vapor to solid (snow)
What is the Adiabatic cooling process
Air changes without the addition or subtraction of heat
What term in the adiabatic process describes when the clouds form, temp and dew point are the same
Level of condensation
Difference between CU and CB
CU - cumuliform (only has updraft)
CB - cumulonimbus ( has moisture, rain, ice)
NS
Nimbostratus, dense, threatening clouds
ST
Stratus, horizontal without rain
Primary cause of frontal weather
Lifting of warm moist air by colder dense air
4 changes for frontal symbol
Temp, moisture, pressure, wind shift
Which fronts have a temp inversion?
All
Cold front description
1/80, steep slope, moves to SE, AVERAGE SPEED 25-30 KTS
What is the wind direction change ahead vs behind a cold front
Behind winds from NW
In front winds are from SW 90º shift
What happens in front of fast moving cold front?
Squall line, tornados, hail, destructive winds
Warm front description
Shallow slope 1/200, moves to NE, slower than cold front, behind the front the winds come from the SW, in front of the front the winds are coming from the SE.
Where does the warm front weather occur?
In front of the warm front
Wind direction on either side of stationary front go what way?
Wind is parallel to the front and going opposite directions
What front has the worst weather?
Occluded, has both cold and warm front weather
When flying near a warm front, what are your action?
Have alternate landing location,
When flying near cold front what are your actions?
Land and wait or circumnavigate
What is your occlusion flight procedure
Circumnavigate or land and wait
Easily recognizable indicators when flying through a front
Wind shift 90º
Temperature change
4 conditions for formation of fog
Temp and dew point near 2º
Light surface wind
Cooling land surface
Condensation nuclei
3 factors for dissipation
Strong winds
Heating
Greenhouse effect/overcast sky
What prevents fog but can prevent dissipation of fog
Overcast sky/greenhouse effect
What kind of fog is when moist air flows over cold surface?
Advection fog, happens near bodies of water
What kind of fog happens through adiabatic cooling?
Upslope fog
Fog that happens through deposition
Ice fog
Radiation fog is caused by what process?
Radiation
Small water droplets falling through inversion temp is what kind of fog?
Precipitation fog
Difference between rime ice and clear ice
Rime is milky, caused by warm front, Small water droplets,
Clear is large and caused by freezing rain
7 hazards of icing
Loss of visibility,
Loss of auto rotation,
increase in drag and weight,
Caused rotor blades to stall sooner
If pilot systems get clogged what happens?
Airspeed indicator is affected
3 conditions for thunderstorm to form
Unstable air,
high moisture,
lifting action
3 categories of thunderstorms
Air mass
Orographic
Frontal
3 stages of thunderstorms
Cumulus
Mature
Dissipating
How do you know a cloud left cumulus stage for mature
Rain starts, up and down drafts, has the most turbulence
Typical conditions for a dry microburst to occur
Mid summer
Between 11 am and 4 pm
Produced from a cumulus cloud,
Has a Virga (ring of dust)
OWS FREEZING LEVEL CHART IS IN WHAT?
Thousands! 16 is read as 16,000
First source for planning DOD flight
Local weather