Weather (theme 2) Flashcards
What causes wind
Differences in air pressure
What happens when there are different air pressures
Air moves from an area of high pressure to an area of low pressure the greater difference in air pressure the stronger the winds
How is sun’s energy spread at the poles
Spread over large area resulting in low temps and high pressure
How is sun’s energy spread at the equator
Concentrated in a small area resulting in high temps and low pressure
3 convection cells
Hadley ferrel polar
7 stages of global atmospheric circulation
- Warm air rises from equator creating belt of low pressure as air rises it cools
- Condensation creates clouds and rain that move north and south of the equator
- At 30 North and south cold dry air skins creating high pressure and clear skies
4.when sinking air reaches earth’s surface ut noves either back to equator or towards poles
- At 60 North south equator surface air meets Colfer air from the piles which rises creating a bley of low pressure
- air rises and colds moves back yo equator or towards the poles
- At piles coil air skins so highn pressure and moves back to equator
What is an air mass
large pocket of air in the atmosphere
What air masses affect the uk?
Polar maritime
Arctic maritime
Polar continental
Tropical Maritime
Tropican continental
Types of surface winds
Trade winds, westerlies
What are trade winds
30 degrees north/south back towards the equator
winds from the northern and southern hemisphere meet at the equator and are heated
What are westerlies
30 degrees north to the north pole and south to the south pole
What are surface winds
At 30o north and south, the air from the equator cools and falls. When the cool air reaches the Earth’s surface, surface winds blow the cool air either towards the equator, or away from the equator towards the Poles.
Features of arid climate zones
Temperatures are high and rainfall is low for most of the year in arid (dry) regions.
Rainfall is low because of a high pressure belt caused by sinking air from 2 cells meeting at about 30o north and south of the equator.
Features of temperate climate zones
Temperate regions experience moderate summers and winters.
Rainfall is frequent because of a low pressure belt caused by rising air from 2 cells meeting at about 60o north and south of the equator.
Features of tropical climate zones
Temperatures and rainfall are high throughout the year in tropical regions.
Rainfall is frequent because of a low pressure belt caused by rising air from 2 cells meeting near the equator.
Features of Polar climate zones
Temperatures are low throughout the year in polar regions.
Factors that affect climate
Latitude
Altitude
Distance from sea
Global atmospheric circulation
How does latitude affect climate
-Affects how much sun a place gets and how strong it is in different seasons
-Further away from the equator cooler
-Closer to the poles sunlight has a larger area of atmosphere to pass through so more energy is lost so cooler
How does Air pressure affect climate?
-Areas of low pressure develop clouds and precpitation while high pressure brings clear sunny weather
How does global atmospheric circulation affect climate?
The Earth’s atmosphere is split into a
number of cells. Each cell is either high
or low pressure. Depending on the type
of pressure the air will either be rising
or sinking.
The Ferrell Cell meets the Polar Cell at
around the same latitude as the UK.
Here warm moist air will meet cool dry
air this leads to a low pressure weather
system where there will be poor
weather e.g. rain and wind.
The Jetstream can make this weather
better or worse.
How does altitude affect climate?
Altitude is the height above sea
level
Locations at a higher altitude
have colder temperatures.
Temperature usually decreases
by 1°C for every 100 metres in
altitude.
In the mountainous areas of the
UK the weather will be cooler
than at sea level.
How does distance from the sea affect climate
Oceans heat up and cool down
much more slowly than land.
This means that coastal
locations tend to be cooler in
summer and warmer in winter
than places inland at the same
latitude and altitude.
Driest weather in the UK
South east
Most rainfall in the UK
North west
What are depressions
Areas of low air pressure which produce cloudy rainy and windy weather
When warm air is rising pressure is
Low pressure because the air is moving away from the earth
What are anticyclones
Areas of high pressure, as the air sinks it warms up leading to warm and dry weather
When cold air sinks pressure is….
High because air is moving down towards the earth pushing down on the surface
Conditions of low pressure events
-Rainfall storms, wind
Conditions of high pressure events
Heat waves, calm days, cloudless skies
Causes of an urban heat island
During the day, concrete, brick and tarmac
absorb the heat from the sun. This heat is
then radiated into the atmosphere during the
evening and at night.
Buildings that are badly insulated lose the
heat energy, especially through roofs and
windows.
Heat is also created in cars and factories and
this heat is also lost to the air from exhausts
and chimneys.
What is an urban heat island?
urbanized areas that experience higher temperatures than outlying areas
Example of high pressure weather event case study
California drought
Conditions needed for hurricane formation
Tropical Storms start within 8º and 15º
north and south of the equator where
surface sea temperatures reach 27ºC.
The air above the warm sea is heated and
rises. This causes low pressure.
Warm water heats the air causing it to rise really
quickly, then it gets pushed aside as it cools.
This pushing causes the clouds to spin.
Features of a huricane
-Winds faster than 118km/h
-Storms have a central area of calm known as the eye which is the funnel that warm air rises
Low pressure event on a HIC case study
hurricane katrina
Hazards of a hurricane
-Strong winds
-Heavy rain
-Storm surges
Ocean hurricanes form over
Atlantic
Ocean cyclones form over
Indian
Ocean typhoons form over
Pacific
Economic impacts of katrina
60 000 homes damaged beyond repair
Economic cost 300 billion
60 percent of jobs lost
Social impacts of katrina
90 percent of children lost education
1200 people died
1 million made homeless short term and permanent
Environmental impacts of katrina
44 oil spils damaged wet lands
Significant coastal erosion and tree loss
Why was new orleans so affected by Katrina
6 feet below sea level due to removing water in medieval times
Economic impacts of Alia
1/2 year salary to replace
Lost income from livestock
Not enough money to repair houses
Social impacts of Alia
Contaminated water supply
People had to move due to devastation but some could not afford to
Breeches in embankments meant areas kept reflooding
Response for hurricane Alia
-whitihin hours charities sent in relief with clean water blankets etc
-soap supplied to stop disease
-health classes
Jet stream
Fast flowing current of air that controls storms
Causes of california drought
-Lack of snow in winter less snow melt filling resivours
-Resivourie hold 1/3 of LAs water
-Farmers used 80 pervent of water
Social impacts of Cali dorught
People had to cut 1/4 of water
Cracks in buildings and roads
Dams stopped producing electricity
Environmental impacts of drought
Ecosystems suffr due to lack of water
31 00 oak habitat burned
Salmon and trout died in rivers
Economic impacts of Cali drought
Not enough water to plant fields
17 100 jobs lost to drought
Responses to Cali drougt
-2.5 billion in new resiovours
-5 billion in groundwater storage schemes
-Gov paid 687 million in compensation
