Weather Theory Flashcards
primary characristic of the Troposphere
in temperature laspe rate
troposphere is thickest at the
equator
acerage thickness of the troposphere in the mid latitudes
36000’
wind speed decreases with altitude in the
stratosphere
primary characteristic of the tropopause
an abrubt change in temperature lapse rate
average depth of the trop
no more than a few 1000’/varies
max wind speed normally occur in the
trop level
largest atmospheric layer
stratosphere
primary characteristics of the stratosphere
primarily isothermal
the trop height with increased temps
increases
ISA stands for
International Standard Atmosphere
Average ISA temps
15C and 59F
Average sea level pressure
1013.2mb and 29.92hg
air density. woth increased temps
decreases
air pressure with increased altitude
increases
Freezing Level def
altitude at which temp is 0C
what is a temp lapse rate
decrease in temp/ increase of altitude
average temp lapse rate in troposphere
2C/1000’
ISA+10C
Decrease air density and aircraft preformance
inversion definition
inverted temperature lapse rate
Inversion hazards
Icing, Turublance, and poor visability
Station pressure code
QFE
station pressure is the
actual pressure at field
Local altimeter setting is
QNH
normal pressure lapse rate is
1 inch hg/1000’ up to 10,000’ MSL
pressure lapse rate above 10,000’ MSL
slows to less than 1in hg/1,000’
pressure drops faster in
colder air
Define True Altitude
actual altitude above MSL
Define Absolute Altitude
Actual altitude above terrian
Define Indicated Altitude
altitude above MSLl indicated on altimeter when using local altimeter setting
indicated altitude is normally used below
18,000’ MSL
High to low pressure
TA is IA
less than
Low to High pressure
TA. IA
larger than
Define Pressure Altitude
indicated altitude when using 29.92hg as the setting
lower pressure results in a. pressure altitude
higher
Aircraft have PA limits for. and.
takeoff
Landing
Define Density Altitude
Pressure Altitude corrected for non-standard temperature
isobar is a line of
equal pressure
Dewpoint Definition
the temp to which air must be cooled to become fully saturated
IFR
C less than 1000’
and or
V less than 3sm
3 conditions for mountain wave
wind speeds at or above 30-40kts
winds blowing perpendicular to the mountains
stable air
Realitive humidity def
the ratio of water vapor in air compared to the total amount of water vapor that air can hold
Air mass definition
a body of air with uniform temperature and moisture
front def
the boundry between two air masses
