Unit 2 Notes Flashcards
What are the zones of climate in the world?
Equatorial, Arid, Mediterranean, Temperate, Mountains, Polar.
What are the Seasonal variations of climate?
The Earth is tilted at 23.5 degrees, which affects the intensity of insolation at a point on Earth’s surface during a year.
What date do the Spring and Autumn Equinox occur?
Spring - March 20th/21st. Autumn - September 22nd/23rd.
What date do the Winter and Summer solstices occur?
Winter - December 21st/22nd. Summer - June 21st/22nd.
At what angle does the sun strike the Earth’s surface on the 21st June?
90 degrees, at the tropic of cancer, 23.5 degrees N of the Equator.
Which part of the Earth has 24 hours of daylight on 21st June?
The Arctic circle, above 66.5 degrees N.
Which part of the Earth has 24 hours of darkness on 21st June?
The Antarctic circle, below 66.5 degrees S.
Where do the Sun’s rays strike on 21st March and September?
90 degrees - The Equator.
How much daylight do all areas receive on 21st March and September?
12 hours of daylight and darkness.
Where is the Sun directly overhead on 21st December?
The Antarctic circle.
When does the pattern of the tricellular model shift Northwards?
Towards from December to June.
When does the pattern of the tricellular model shift southwards?
From June to December.
What does the shift of the Heat Equator cause?
Large seasonal variation in climate.
Why does large seasonal variation in climate only occur in the tropics?
Low pressure associated with meeting of two Hadley cells - the ITCZ moves northwards and southwards.
What does the low pressure zone of the ITCZ move in response to?
The movement of the Heat Equator.
Where is the movement of the Heat Equator most pronounced?
Over large land masses, which heat up more quickly than areas of ocean.
What does the shift of the ITCZ cause for wind direction?
Seasonal changes in wind direction and precipitation, leading to a wet and dry season.
In which months of the year is precipitation high in Zambia?
December, January, February, 20cm of rainfall, because the ITCZ is near Zambia, in the Southern Hemisphere.
In which months of the year is precipitation low in Zambia?
June, July, August, with around 0cm of rainfall, as the ITCZ is further away from Zambia.
In what months of the year is precipitation high in Chad?
July, August, September - around 20cm of rainfall, because the ITCZ causes low pressure in summer.
In what months of the year is precipitation low in Chad?
December, January, February, March - around 0cm of rainfall, as the ITCZ shifts southward, further away from Chad, leading to a lack of moisture.
Which parts of the year are the wettest for regions on the Equator?
March and September.
What is a Monsoon?
A seasonal change in wind direction, linked to changed in Atmospheric pressure.
What happens to air in a high pressure system?
Sinking.
What happens to air in a low pressure system?
Rising.
What happens to the weather and wind direction in an area when atmospheric pressure changes?
They change as well.
When does the hot, dry season occur in India?
February-May.
What happens to land in India during the hot, dry season?
Land begins to heat up more than surrounding ocean, absorbing insolation rapidly.
What has happened by May in India?
Temperatures can exceed 40 degrees over the landmass of India, which is 20 degrees more than the surrounding Ocean.
What happens to the Atmosphere in the hot, dry season?
The land heats the atmosphere, warm air begins to rise, creating an area of low pressure.
When is the rainy season in India?
June-August.
What has happened by June in India?
Low pressure ITCZ starts to spread Northwards.
What type of wind develops?
South Westerly wind, as warm moist air from the Indian Ocean is drawn into low pressure, resulting in rainfall.
What happens by Mid July?
The monsoon rains have reached the whole country, precipitation over much of India are usually between 300-700mm.
What is an example of additional orographic uplift in India?
The Western Ghats - 1500mm of rainfall.
What happens as the heat equator travels south?
Insolation levels drop, landmass of India starts to cool down.
What does the Indian Ocean have which helps it stay warm during the cold season?
A high specific heat capacity, retaining most of its’ heat.
What does a high specific heat capacity cause?
The Ocean has warmer air above it, therefore low pressure ITCZ shifts here.
What do cold land masses experience?
High pressure.
What happens to India during December and January?
Much of Northern India has an average temperature of below 15 degrees, receives virtually no rainfall.
Which other factors affect tropical climates?
Ocean currents, Altitude.
How does Altitude in India exacerbate Monsoon?
Higher altitudes create orographic rainfall.
Why is the Atacama Desert dry?
Because Altitude of the Andes stops moisture from reaching the desert.
What are the most common winds in India?
South East trade winds.
What do South East trade winds do?
Carry moist air from the Atlantic, winds are cooled, as they’re forced to cross the Andes.
What are the characteristics of the UK climate?
Relatively mild temperatures, 5-20 degrees. High humidity and precipitation - 800mm throughout the year.
Why does the UK have a cool temperate climate?
It lies between sub tropical and polar zones.
What was the highest temperature ever recorded in the UK?
40.3 degrees - 2022 - Lincolnshire.
What was the lowest temperature ever recorded in the UK?
-27.2 degrees - Scotland.
What is the variation in average temperature across the UK?
4 degrees - Highlands. 11 degrees - South East.
What happens to average temperature in july in the UK?
Highest temperature can average over 17 degrees, lowest can be below 10 degrees.
Where are the warmest parts of the UK in January?
Around the South and West coasts - over 6 degrees.
Where are the coldest parts of the UK in January?
The Scottish highlands - Below freezing.
How much colder is Irkutsk, Russia than London in January?
24 degrees.
How much warmer is Irkutsk, Russia than London in July?
1 degree.
What is the annual temperature range of Irkutsk, compared to London?
13 degrees - London. 38 degrees - Irkutsk.
Why is there a difference between the ranges?
The UK has a maritime climate, protected by Coastline. Irkutsk has a continental climate, not surrounded by Coastline.
Which types of precipitation does the UK experience?
Frontal, Convectional, Orographic.
What is the Correlation between Altitude and Precipitation?
It rains on average 130 days per year, 1/3 of the days. Some places have 100 days, some have over 200.
What is the average total rainfall for the UK?
800mm, but it varies.
Where is the driest place in the UK?
St. Osyth - Essex.
Where is the wettest place in the UK?
Snowdonia, Lake District.
What % of the UK’s wind blows from the West, South West, or South?
48%.
What is an Air Mass?
A large body of air with distinctive characteristics. Air from different directions bringing a particular type of weather.
What is a Maritime Air Mass?
Originates over the Ocean, moist.
What is a Continental Air Mass?
Originates over continentality.
Where do tropical continental air masses form?
Southern Europe and Northern Africa.
When do Tropical continental air masses occur?
The summer.
What are the characteristics of a Tropical Continental Air Mass?
Hot, sunny, dry, potentially thunderstorms due to warm air.
Where does a Tropical Maritime air mass form?
Atlantic Ocean.
What are the characteristics of a Tropical Continental air mass?
Warm, moist air. Cloud, rain, mild weather.
Where do Polar Continental air masses form?
Eastern Europe, Easterly winds. North Sea.
What are the characteristics of a Polar Continental air mass?
Picks up moisture, significant snow showers.
Where does a Polar Maritime air mass originate?
Greenland, Canada, North Atlantic.
What happens to air in a Polar Maritime air mass?
Air’s heated from below, making it unstable.
What are the characteristics of a Polar Maritime air mass?
Rain, hail, thunder, sleet, snow, potentially sun.
Where do Arctic Maritime air masses form?
In the Arctic, in winter months.
What happens to air in Arctic Maritime air masses?
Picks up moisture over warmer seas.
What are the characteristics of Arctic Maritime air masses?
Cold air, snow, blue skies.
Where do Returning Polar Maritime air masses originate from?
Greenland, Canada.
What are the characteristics of Returning Polar Maritime air masses?
Milder, more clouds and rain.
Which factors determine which air mass we experience?
Winds blowing out of a HP area in a clockwise direction. Winds blowing into a LP system in an anti-clockwise direction.
What are Isobars?
Lines of equal atmospheric pressure.
What are the most common air masses?
Tropical and polar maritime.
What is the least common air mass?
Polar continental.
Why is UK weather unpredictable?
The latitude of the UK is the meeting point of two circulation cells - the polar cell and the Ferrel cell.
What is the Polar front?
The meeting point of the Ferrel and polar cell.
What is the Jet Stream?
The difference in the temperature of the colliding cold air from the north, and warm tropical air from the south, creating a fast moving high altitude wind.
What are the changes in the Jet Stream called?
Rossby waves.
What happens to Rossby waves when the flow of air slows down?
They become more extreme, and become less extreme when air flow increases.
What is speed of air flow in the jet stream a function of?
A function of temperature difference between colliding polar and ferrel cells at the polar front.
What does the position of the Rossby wave affect?
The position of high and low pressure systems around the UK.
What is a depression?
Low pressure zones where air rises.
What happens during a depression?
Cooling of air, condensation of water vapour, cloud formation, precipitation.
What is stage 1 of depression formation?
Along the polar front, there will be a temperature difference between colliding air masses - polar maritime and Tropical maritime.
What happens where temperature difference is great?
Uplift occurs, creating low pressure at ground level.
What is stage 2 of depression formation?
Air at ground level is drawn into low pressure areas to replace that which has been uplifted.
Why is air in stage 2 deflected?
The Coriolis effect - air flows towards the low pressure, creating an anti clockwise circulation of air.
What is stage 3 of depression formation?
Due to anti clockwise rotation of air into the centre of low pressure, polar front develops.
What does the development of a polar front create?
An embryo depession on the west side of low pressure, where cold PM air is forced into warm TM air, creating a cold front.
What happens on the East side of low pressure in stage 3?
Warm TM air is being forced into the cold polar maritime air, creating a warm front.
What happens along the warm front, when less dense air is forced upwards?
Warm air, being less dense, is forced over the cold air, therefore forced to rise.
What happens along the cold front, when less dense air is forced upwards?
Cold air, which is more dense, undercuts the warm air, which is forced to rise.
What is the role of the jet stream?
Low pressure systems form regularly in the North Atlantic Ocean, due to warm TM air.
What happens when air collides with PM air?
Uplift results in a large amount of condensation.
What does rising depression air lead to?
Air is drawn into the jet stream, dragging the LP system in an Easterly direction.
What is the most common wind direction in the UK?
South Westerly winds.
What is the most common air mass affecting the UK?
Tropical Maritime.
What is the climate of Scott, Antarctica?
Found below the tropics, large seasonal variations in temperature. Sun is more intense in summer months. Cold desert - very little rainfall.
What is the climate of Cairo, Egypt?
Hot desert - almost no rainfall. Mid range seasonal variation in temperature - 15 degrees. Outside of the tropics - less affected by ITCZ.
What is the climate of Irkutsk, Russia?
Large variation in temperature in summer and winter continentality. On the same latitude as the UK, SHC of land is lower than water - doesn’t take as long to heat up. Colder in winter, warmer in summer.
What is the climate of Jakarta, Indonesia?
Same temperature all year round, maritime, very close to equator, intensity of sun is felt all year round - goes directly on equator. Surrounded by water - SHC is higher - takes longer to heat up.
