Meteorology Flashcards
Mean sea level T
15°C
Mean sea level P ?
1013.25 hPA
Mean sea level density p ?
1.225 Kg/m3
Temperature lapse rate ?
1.98°C / 1000 ft up to tropopause
Tropopause altitude ?
36090 ft (36000 ft / 11km) (-56.5°C)
Pressure lapse rate
27 ft / hPA ( 30 ft/hPA)
Density lapse rate
- NON LINEAR
- 22 000 ft = 50% (0.6 Kg/m3)
- 40000ft = 25 % (0.3 Kg/m3)
Explain Inversion at the tropopause
- O3 ozone : O3 absorb uv radiation from the sun and projects that heat out an dheats up the surrounding air
Stratopause altitude :
50 km
Mesopause altitude
80 km
What’s insolation :
It’s how much energy is absorbed by the earth surface per unit area
Formla to convert “T” to “F”
°F= (1.8 x °C)+32
Short explanation of Diurnal variation
When its gets cold at night
What’s the phenomena that heat the air (7), specify and explain them ?
- Conduction : Heat through contact
- Convection : Altitude increase, density decrease, wich dissipate heat into the surrondding air
- Advection : Warm air come from a hotter side
- Turbulence : Mixing air
- Latent heat : clouds wich dissipate energy
- Radiation : Long waves radiation reflected by the surface and then heat air molecules
- Inversion : T increase when ALT increase
Low energy sun rays
What are types of inversion, explain them ?
- Ground inversion : Cold clear nights with very low wind, results fog or low clouds
- Subsidence inversion : Air is force down from mountain ( wairm air keep above cold air)
- Frontal inversion : Air rolls in and the warm air sits on top of the colder air
Relation between P, T, H, and Density ?
Density = P/(TH)
Formula to calculate density altitude :
Density altitude = Pressure altitude +- (120 x ISA Dev)
QFF lapse rate (how to calculate the true altitude)
- 4 ft / 1000 ft / ISA Dev ; or
- +- 1% ALtitude per 2.5 ISA Dev
QFF = altitude using daily lapse rate
Difference between ISOBARS ?
4 hPA or 2 hPA
Direction of rotation of H/L ?
- High pressure : Clock direction (Horloge)
- Low pressure : Anti-clock direction
Formula of relative humidity ?
RH = AWVP / SWVP
* Dew point : RH = 100% ( AWVP = SWVP)
- AWVP : Actual Water Vapour Pressure
- SWVP : Saturated Water Vapour pressure
Formula of Humidity mixing ratio
Humidity mixing ratio = Mass of water vapour / 1Kg of Air
Ex :
RH of 100% = 16 g/Kg
RH of 50% = 8g/Kg
Formula of Absolute Humidity
Absolute Humidity = Mass of water vapour / 1m3 of air
Ex :
RH of 100% = 16 g/m3
RH of 50% = 8g/m3
