Meteorology Flashcards
78% Nitrogen21% Oxygen1% other
Atmosphere Gases
0 - 36,000 feet or 6.8 miles15 °C (59 °F) to -56.5 °C (-70 °F)Temp decreases with altitude.
Troposphere
Tropopause up to 31 milesAn average -56.6 °C (-70 °F) at the tropopause to a maximum of about -3 °C (27 °F) at the stratopause due to this absorption of ultraviolet radiation. Temp increases with altitude.
Stratosphere
Stratopause to about 53 miles. -3 °C (27 °F) to as low as -100 °C (-148 °F) at the mesopause.Temp decreases with altitude.
Mesosphere
Mesopause up to 430 miles.2,000 °C (3,600 °F) but air too thin to feel heat on skin.Temp increases with altitude.
Thermosphere
Basically spaceUp to 6200 miles
Exosphere
TroposphereStratosphereMesosphereThermosphereExosphere
Layers of the Atmosphere
[°F] = ([°C] x 9/5) + 32 1.8C times 2, less 10% of that, plus 32
Celsius to Fahrenheit
[°C] = ([°F] – 32) x 5/90.5555555556
Fahrenheit to Celsius
Conduction - solid material Convection - liquids and gasesRadiation - electromagnetical waves
Types of heat transfers
An isothermal layer is a layer within the atmosphere where the temperature remains constant with height
Isothermal Layer
1013.2 hPa METAR/SPECI
Hectopascals Standard Atmosphere
1013.2 mb U.S. Weather Charts
Millibars Standard Atmosphere
29.92 inHg U.S. Aviation
Inches of mercury Standard Atmosphere
14.7 psi U.S. Engineering
Pounds per square inch Standard Atmosphere
Actual vertical distance above MSL.
True Altitude
Indicated on the altimeter when set at the local altimeter setting.
Indicated Altitude
The corrected (approximately true) altitude is indicated altitude corrected for the temperature of the air column below the aircraft, the correction being based on the estimated deviation of the existing temperature from standard atmosphere temperature.
Corrected Altitude
Shown by the altimeter when set to 29.92 inchesof mercury.
Pressure Altitude
Pressure altitude corrected for temperaturedeviations from the standard atmosphere.
Density Altitude
At a specified indicated airspeed, the pilot’s true airspeed and groundspeed increase proportionally as density altitude becomes higher.
Affect of Density Altitude on Airspeed
density altitude = pressure altitude + [120 x (OAT - ISA Temp)] -2°C per 1000’ PA to get ISA temp
Formula for Density Alt
pressure altitude = (standard pressure - your current pressure setting) x 1,000 + field elevation
Formula for Pressure Alt
Pressure gradiant force (pfg)Coriolis forceFriction
Forces that affect wind
Wind moves from high to low, perpendicular to isobars.Wind speed is directly proportional
Pressure Gradiant Force
Right angle (in northern hemisphere) to wind direction and directly proportional to wind speed.Zero at the equator max at the poles.
Coriolis Force
Parallel to isobars, no friction
Wind direction at altitude influenced by pressures
On climb out hits more from the rightClockwise out from highCounterclockwise in to low
Wind direction at surface, northern hemisphere, as influenced by pressures
Low latitudetowards equator at surfaceTowards poles at altitude
Hadley cell
Mid latitudeTowards poles and East at surfaceTowards equator and West at altitude
Ferrel cell
Converges at poles and sinks to the surface. Easterly (out of East) at surface.
Polar cell
sea breeze, land breeze, lake breeze, lake effect, valley breeze,mountain-plains wind circulation, and mountain breeze.
Local winds include:
A sea breeze is a coastal local wind that blows from sea to land, and caused by temperature differences when the sea surface is colder than the adjacent land.
Sea Breeze
A land breeze is a coastal breeze blowing from land to sea caused by the temperature difference when the sea surface is warmer than the adjacent land. Land breezes usually occur at night and during early morning.
Land Breeze
A lake breeze is a local wind that blows from the surface of a large lake onto the shores during the afternoon and is caused by the temperature difference when the lake surface is colder than the adjacent land.
Lake Breeze
A valley breeze is a wind that ascends a mountain valley during the day.
Valley Breeze
During the daytime, this wind system is the equivalent of one-half of a valley breeze. Air in contact with the sloping terrain becomes warmer (less dense) than air above the plains.
Mountain - Plains Wind System
A mountain breeze (see Figure 9-10) is the nightly downslope winds commonly encountered in mountain valleys. Air in contact with the sloping terrain cools faster than air above the valley.
Mountain Breeze
significant temperature gradients,winds usually converge;and pressure typically decreases as a front approaches and increases after it passes.
Fronts are usually detectable at the surface in a number of
Cold fronts have a steep slope, and the warm air is forced upward abruptly. This often leads to a narrow band of showers and thunderstorms along, or just ahead of, the front if the warm rising air is unstable. Cold always stays underneath.
Cold Front Slope
Warm fronts typically have a gentle slope, so the warm air rising along the frontal surface is gradual. This favors the development of widespread layered or stratiform cloudiness and precipitation along, and ahead of, the front if the warm rising air is stable. Cold always stays underneath.
Warm Front Slope
Stationary frontal slope can vary, but clouds and precipitation would still form in the warm rising air along the front.
Stationary Front Slope
Cold pushes under Warm with brute force. Y shaped.
Occluded Front Slope
A low pressure circulation that forms and moves along a front. The circulation about the cyclone center tends to produce a wavelike kink along the front. Wave cyclones are the primary weather producers in the mid-latitudes. They are large lows that generally travel from west to east along a front. They last from a few days to more than a week. Starts from a Stationary Front.
Wave Cyclone
A dryline is a low-level boundary hundreds of miles long separating moist and dry air masses. In the United States, it typically lies north-south across the southern and central High Plains during the spring and early summer, where it separates moist (mT) air from the Gulf of Mexico to the east and dry desert (cT) air from the southwestern states to the west.
Dryline
3 deg C per 1000’Dew point decreases by 0.5 deg CThe parcel’s temperature-dewpoint spread decreases, while its relative humidity increases.
Dry adiabatic lapse rate
varies between approximately 1.2 °C per 1,000 feet (4 °C per kilometer) for very warm saturated parcels to 3 °C per 1,000 feet (9.8 °C per kilometer) for very cold saturated parcels.dewpoint decreases at an identical rate.
Moist adiabatic lapse rate
orographic effects, frictional effects,frontal lift,and buoyancy.
Common Sources of Vertical Motion
Absolute stabilityNeutral stabilityConditional instabilityAbsolute instability
Types of stability
