CPL Meteorology Flashcards
Atmosphere Composition
78% Nitrogen 21% Oxygen 1% Other (CO2 etc.)
Water Vapour Composition
Minute Traces to about 3%
How high is the Ozone Layer?
50km
Why is the sky blue?
Blue wavelength of visible light is scattered.
Layers of the atmosphere:
Troposphere, Tropopause, Stratosphere, Stratopause, Mesosphere, Mesopause, Thermosphere, Exosphere
ELR in troposphere
2 degrees per 1000ft height increase
What is the region called where the temperature remains constant with a height increase?
Isothermal layer
Height range of the tropopause
8km (poles) to 18km (equator)
Height of the tropopause over Australia
~10km
What are the types of cells found around the Earth called used to distribute heat from the equator?
Convective Cells
Sinking air produces what kind of pressure?
High Pressure
Rising air produces what kind of pressure?
Low Pressure
Region of rising warm air at the equator?
Equatorial Trough (Tropical Cell)
Region of sinking air at mid lattitude?
Sub-Tropical Ridge
Region of rising air and low pressure near the poles?
Sub-Polar Low
During the southern hemispheres summer:
The southern hemisphere is tilted towards the sun - more water than land therefore summer brings the ‘wet’ season and vast quantities of water vapour are taken up by the rising air.
Another name for the region where surface air flow from each hemisphere converges and rises:
The Inter-Tropical Convergence Zone (ITCZ)
During the northern hemispheres summer:
The northern hemisphere is tilted towards the sun - more land than water therefore the equatorial trough moves up as the land becomes hotter in summer than the same latitude of the southern hemisphere.
What is the movement of the equatorial trough called?
Migration
Does air flow between a high to a low or a low to a high?
High to a low
Which way does the Earth rotate?
West to East
What are the winds called that move from the sub-tropical ridge to the equatorial trough?
South East Trades
Which direction does a high pressure system circulate?
Anti-Clockwise
Which direction does a low pressure system circulate?
Clockwise
Which direction is wind direction usually?
Parallel to the isobars - clockwise about a low and anti-clockwise around a high
Cyclonic or anti-cyclonic in a low?
Cyclonic
Cyclonic or anti-cyclonic in a high?
Anti-Cyclonic
What is an El-Nino event?
Warm surface water begins to move eastward to bring lower than usual atmospheric pressure to the Eastern Pacific. This weakens the pressure difference across the ocean and the trade winds will falter or even reverse. This allows the pile-up of warm surface water to ‘slosh’ East across the pacific further reducing atmospheric pressure. This atmospheric lifting is enhanced bringing heavy rains to the normally dry west coast of South America. Simultaneously, air subsiding over the Western Pacific and Indian Ocean brings very dry air to the Australian continent creating drought conditions.
