T-6 JX 101 Flashcards
From surface up, what are the atmospheric layers
Troposphere (^36,000’)
Stratosphere
Ionosphere
Troposphere characteristics
large amounts of moisture and condensation nuclei
Nearly all weather occurs here
What is the abrupt change layer in the rate of temperature decrease?
Tropopause
Tropopause definition
A transition zone between the troposphere and stratosphere. (^36,000’ MSL)
Stratosphere Characteristics
Temp. Inversion
from 36,000’-66,000’
Smooth, thin air
Excellent Visibility
Standard lapse rate
2°c per 1000’
Isothermal lapse rate
Temperature is constant with increasing altitude
Inverted lapse rate
Temperature increases with increased altitude
What is Atmospheric (barometric) pressure
The pressure exerted on the surface by the column directly above it
What are the two units of measurement for atmospheric pressure
Inches of mercury (inHg)
Millibars (mb)
Standard day pressure and Temperature and lapse rate
29.92 inHg / 1013.2 mb
15°c / 59°F
1 inHg per 1000’
Define Station Pressure
Atmospheric pressure measured directly at an airfield or other weather station
Define sea level pressure
The pressure measured from the existing weather if the station were at MSL
Changes in sea level pressure Memory Jogger
“High to low, look out below”
“Low to high, plenty of sky”
Altimeter error temperature
4% per 11°c
Indicated Altitude
What is read on the altimeter
Absolute altitude
Altitude AGL
True Altitude
Altitude in reference to MSL
Pressure Altitude
Altitude above the standard datum plane (29.92 inHg)
Density Altitude
Pressure altitude corrected for temperatude deviations
Pressure gradient directions
High - Outwards/Clockwise
Low - Inwards/Counterclockwise
In what direction do gradient winds flow (Above 2000’ AGL)
Parallel to the isobars
In what direction do gradient winds flow (Below 2000’ AGL)
45° to the isobars
The average height/speed of the jet stream
30,000 MSL
100-150 (up to250 mph)
What are local winds
Geographically thin areas created by mountains, valleys, and bodies of water.
Superimposed on general winds causing significant changes in weather
Describe Sea breezes
Warm air cooling and descending over water, gets pushed towards land. This air hits land, warms up, and rises being pushed back towards the sea
Describe land breezes
warm air rising over warm water, pushed towards land, cooled and descends and pushed back towards the sea
Describe mountain and valley winds
Day / Night
During the day, cold air descends and pushes out the warm air in the valley, it is then pushed up towards the peaks.
During the night, air in contact with the slope is cooled by terrestrial radiation then becomes denser, the air then flows downhill.
3 states of water
Solid, liquid, gas
War vs. Cold air dewpoint
Warm air can hold more water vapor than cold air.
Air can reach saturation when it contains the max amount of water vapor
What is dewpoint
The temp at which saturation occurs
The higher the dewpoint the greater chance of fog/clouds/precipitation
What is relative humidity
The percent of saturation in the air, or the percent of water vapor in the air compared to the max it can hold at that temp
types of precipitation
Drizzle - liquid and freezing
rain - liquid and freezing
frozen - hail, ice pellets, snow, snow grains
Low/middle/high cloud altitudes
Low - above surface to 6,500’
(Alto) Middle - between 6500’-20,000’
(Cirro) High - from 20,000’-40,000’
4 methods of lifting
Convergence - when 2 air masses converge pushing air upwards
Frontal lifting - moving clod front pushing the air in front of it up
Orographic - wind pushes air up a mountainside
Thermal - cold air is heated by solar heating
