Climate Hazards Flashcards
(44 cards)
Define Solar Insulation
amount of suns energy
How is solar insulation distrubuted
Intense at equator, concentrated dispertion
At poles wide distribution so less intense
How is heat redistrubuted
Ocean currents and circulation cells
What causes circulation cells
differences in pressure
What do ocean currents do
ocean currents bring warm water to colder places by winds
Define wind
Movement of air from high –> low pressure.
Describe a circulation cell
Sun heats surface causing air to rise and expand creating low pressure and rainfall
After it reaches high enough latitude it cools and sinks back to earth to create high pressure and dry conditions
What happens at the Hadley Cell
air reaches about 30 north and south the air cools and sinks forming the subtropical high-pressure zone
Creating an area of little cloud and low rainfall; deserts
What direction do the northeast trade winds go
Winds flow to the right and in northern hemisphere
What direction do the south east trade winds go
In the southern hemisphere and flow to the left
What winds do the ferrel cell form
Air on the surface is pulled towards the poles, forming the warm south-westerly winds in the northern hemisphere and north-westerly winds in the southern hemisphere
How does the ferrel cell cause mid-latitude depressions(UK)
westerly winds pick up moisture over oceans and meet cold air at 60 drifted from trhe poles.
Warmer air lighter than cold so it rises causing low pressure at surface; Uk wet and windy weather
What is the polar high caused by the polar cell
at the poles, air is cooled and sinks towards the ground forming high pressure, this known as the Polar high.
What happens to air from the polar high
Drifts to lower latitudes till it meets warmer air at 60 causing a zone of low pressure called the polar front due to its denseness
What is the tricelluar model
Polar cell Ferrel Cell Hadley Cel Hadley Cell Ferrel Cell Polar Cell
What are the bands of pressure
Polar high Sup-polar low Sub-tropical high equatorial low sub-tropical high sub-polar low polar high
Define the ITCZ
The ITCZ is a zone of convergence at the thermal equator where the trade winds meet. It is a low pressure belt and migrates with the changing position of the thermal equator.
Why is the ITCZ not straight
Landmasses being able to heat quickly and sea releases heat over a long time
What impact does the ITCZ have
Seasonal as ITCZ moves up and down
heats area to create low pressure and constant rainfall
How are deserts created
Hot conditions from being near equator but hardly receives rain from ITCZ
Define Jet Streams
Fast moving jets of air moving in the upper atmosphere
>200mph from west–> east in North Hemisphere
What can cause big differences in weather due to jet streams
Jet streams can buckle due to polar wind or tropical wind moving south or north respectively
What do stationary jet streams cause
Bring frequent depressions to the same region
What is an example of ocean curents
example the gulf stream is a warm ocean current driven by westerly winds. In the north atlantic cold,salty water is heavy and sinks. This sets up a convection current which drags surface water down. The current draws warmer salty water over the ocean surfaces from areas near the equator which cools and sinks in the Labrador and Greenland seas to go back to the Equator where it is warmed again
