The Atmosphere Flashcards
State the composition of the atmosphere
Nitrogen = 78%
Oxygen = 21%
Other gases = 1%
State the pressure lapse rate @ MSL —— per 1 hPa
27 ft/hPa
State the pressure lapse rate @ 10,000ft —— per 1 hPa
36 ft/hPa
State the pressure lapse rate @ 18,000ft —— per 1 hPa
48 ft/hPa
State the pressure lapse rate @ 30,000ft —— per 1 hPa
72 ft/hPa
State the significant pressure level @ 53,000ft ISA
100 hPa
State the significant pressure level @ 39,000ft ISA
200 hPa
State the significant pressure level @ 30,000ft ISA
300 hPa
State the significant pressure level @ 18,000ft ISA
500 hPa
State the significant pressure level @ 10,000ft ISA
700 hPa
State the significant pressure level @ 5,000ft ISA
850 hPa
State the MSL pressure —— ISA
1013.25 hPa
State the MSL density —— ISA
1.225 kg/m(^3)
State the MSL temperature —- ISA
+15 degrees Celsius
State the ISA temperature lapse rate up to 36,000ft, per 1000ft
-1.98 °C per 1000ft
State the ISA temperature lapse rate up to 36,000ft, per 1000m
6.5°C per 1000m
State the ISA temperature deviation equation
ISA deviation = OAT - ISA temperature
State the equation to calculate ISA temperature
ISA temp. = 15 - (2 x altitude)/1000
State the ISA temperature lapse rate between 36,000 - 65,000ft
Trick question - constant temperature of -56.5°C
State the ISA temperature lapse rate between 65,000-105,000ft
+0.3°C per 1000ft
What does ITCZ stand for?
Inter-Tropical Convergence Zone
State the direction of the Coriolis Effect in the Northern/Southern Hemisphere
Anti-clockwise/Clockwise
Name the 3 different air circulation cells
Hadley, Ferrel, Polar
What is Insolation shorthand for?
Incoming Solar Radiation
What percentage of mass in the atmosphere does the Troposphere hold?
75%
What is the approx. Height and temperature of the Tropopause at: 0°-30° latitude?
Height: 55,000ft
Temperature: -75° c
What is the approx. Height and temperature of the Tropopause at:
30°-60° latitude?
Height: 36,000ft
Temperature: -56.5°
What is the approx. Height and temperature of the Tropopause at:
60-°90° latitude?
Height: 26,000ft
Temperature: -50°
Name the 4 different layers of atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere
What happens to the temperature trend at the top of the Thermosphere?
If above the night pole - the temperature will slowly begin to decrease (but a sharp change in trend)
Otherwise, the temperature will continue to increase at the same rate into the positive temperatures
What is the basic trend between the Tropopause maximum height and temperature, at the Equator and the poles - relatively?
Equatorial Tropopause is higher and colder
Polar Tropopause in lower and warming
Draw a labelled diagram of the ‘Generalised Global Circulation’
Things to remember:
- Hadley, Ferrel and Polar Cells.
- Anti-clockwise rotation in the North, Clockwise in the South
- Ferrel Cell opposing the general trend
- ICTZ, Sub-tropical high pressure belts, Polar front, Polar highs
- NE + SE trade winds, SW + NE-lies
Name the factors that influence the amount of water vapour in the atmosphere
- Altitude
- Location
- Temperature
State the definition of Altitude
The physical distance above a datum
Mean Sea Level (MSL) for MET
State the definition of Temperature
The kinetic energy per molecule of a substance
Units: °C, °F, K
State the definition of heat
The kinetic energy per unit volume of a mass
At what latitudes to tropospheric ‘breaks’ occur?
Between 30-60 °N
What radiation does Ozone absorb?
Ozone absorb shortwave length (UV) solar radiation
Where in the atmosphere is the highest concentration of Ozone?
In the low stratosphere
Where does the most solar absorption occur?
What is the result?
Most absorption occurs high in the stratosphere
Which results in a temperature increase
At what altitude do Nacreous (or Mother of Pearl) clouds form?
Between 15-25km in the Polar Stratosphere
What can the Meso/Thermo/Exo-spheres (60-1000km) be collectively known as?
The Ionosphere
Due to the molecules within this level being ionised
What can charge the ionosphere to up to 500KV?
The electrostatic charge created by thunderstorms
Define the Parallels of latitude
What are they also known as?
A circle of latitude that cuts through the Earth at right angles to the pole-line
A.k.a - small circles
What is a ‘Great’ circle?
Any circle that is equal to the diameter of the Earth
Most namely, the Equator
Define the meridians of Longitude
Half of a ‘great’ circle - which passes through the poles
Where does the prime meridian intercept?
Greenwich
This is GMT
Show the equation for the pressure lapse rate
Height change per 1hPa
Height change per hPa = (96T)/P
T = Temperature in K P = Pressure in hPa
What is the pressure lapse rate at MSL?
27 ft/hPa
What is the pressure lapse rate at 10,000ft?
36 ft/hPa
What is the pressure lapse rate at 18,000ft?
48 ft/hPa
What is the pressure lapse rate at 30,000ft?
72 ft/hPa
What is the density lapse rate at MSL?
1.225 kg/m^3 per ft
What is the density lapse rate at 10,000ft?
0.903 kg/m^3 per ft
75% of MSL rate
What is the density lapse rate at 22,000ft?
0.609 kg/m^3 per ft
50% of MSL rate
What is the density lapse rate at 40,000ft?
0.302 kg/m^3 per ft
What is the effect of clouds on the Earths surface temperature?
Clouds cause:
Cooler days - due to reflecting solar radiation
Warmer nights - due to re-radiating Terrestrial radiation
What relationship does wind have with different temperature levels?
In strong winds, different temperature levels will mix.
However, on a still day - different temperature air will not mix
What is Diurnal variation?
The change of temperature over a daily period
Draw a graph of diurnal variation on:
Water, a clear day on land, and a cloudy day on land
Things to note:
- Water has minimal variation due to high specific heat capacity
- Much larger variation on an overcast day, compared to that of a clear day
Define Inversion
An increase in temperature with altitude
Opposing the usual trend of a decrease
Define Isothermal layer
A layer of air with a constant temperature, with an increasing altitude
Define Thermal inertia
The time difference between where there is maximum Insolation and maximum Terrestrial temperature
What is a freezing level?
An altitude where temperature = 0°
