2.3 weather and climate

weather

day to day conditions in the atmosphere

climate

average weather conditions based on averages of 40years of data

temperate climate

a climate that isnt too hot or too cold and has 4 clear seasons

describe coldest and warmest seasons in UK

coldest=jan-feb

warmest-july-aug

where are sunshine hours greatest in UK

south coast of england

which part of UK has shorter winter days and longer summer days

Scotland as it is further north

where is it wettest in UK

west

Snowdonia in Wales-3000 mm of rain a year

which are the driest areas of UK

Parts of the east, such as East Anglia, receive less than 700 mm a year. 

describe average temperature in UK

Average temperatures in UK are warmer at lower latitudes and colder at higher latitudes.

which area is mostly affected by severe weather in UK

Scotland

average daily temps in summer in UK

The average daily maximum temperature at Glasgow in July is 19°C compared with 22°C in London. 

Scotland is 3°C colder than UK

what factors affect UK climate

altitude

distance from sea

air pressure

latitude

influence of global circulation model

how does latitude affect UK climate

• as latitude increases, av temp decreases

• affects how much sun the UK gets during diff seasons

  • the further away from equator, the cooler the area

how does altitude affect UK climate

altitude=height above sea level

• locations at higher altitude have colder temps

• temps decrease by one degree every 100m

  • mountain areas are cooler than sea level areas

how does prevailing wind direction affect climate

prevailing wind=min wind that blows most the time

• everywhere gets lots of diff winds from diff directions

  • the temp and wetness of winds can be affected by what wind travels over

how does global atmospheric circulation affect UK climate

where the air is warm, moist air leads to low pressure weather systems which is poor weather i.e rain and wind

when the air sinks, this leads to drier weathers

how does distance from sea affect UK climate

oceans heat up and cool down much more slowly than land

• coastal areas tend to be cooler in summer and warmer in winter than inland places at the same latitude and altitude

global circulation model

a theory that explains how the atmosphere operates in a series of three cells each side of the equator t

what impact does global circulation model have on world

affects climate across world

leaves tropical areas with little rain

three cells of global circulation model

• Hadley cell(0-30 degrees N and S of equator)

  • Ferrel cell(30-60 degrees N and S of equator)

• Polar cell(60-90 degrees N and S of equator)

Hadley cell location and role

• located near equator

• involves warm, moist air rising leading to frequent rainfall and low pressure

• when air reaches 30 degrees N and S air cools and sinks , it moves towards higher latitudes, descends and creates dry, high pressure zones(deserts)

Ferrel cell location and role

• between Hadley and polar cells

• air on surface is pulled towards poles , forming warm south westerly winds in northern hemisphere and north westerly winds in southern hemisphere

• these winds pick up moisture as they travel over sea

• at around 60 degrees N and S, they meet cold air

• the warmer air from tropics is lighter than dense cold polar air it rises as two airs meet

  • this causes low pressure and unstable weathers

polar cell locations and role

• at the poles, air is cooled and sinks to form high pressure

• it then flows towards lower latitudes

  • at 60 degrees N and S the cold air mixes with warmer tropical air and rises causing low pressure

overview of climate zones on earth

location of semi-arid grasslands

• found mostly in Africa but also Asia, South America and oceania

• between tropics

• close to equator so warm and away from low pressure so dry

temperatures in semi arid grasslands

reach as high as 30°C during the summer months with intense sun, while winter temperatures may drop to around 0°C with frost

vegetation in semi arid grasslands

baobab trees-stores water in trunk

long grass-stores water in roots to survive in fire

acacia trees-long roots to reach water, thorns

animals in semi arid grasslands

zebra-migrates to fresh grass, camouflages

giraffe-long neck to reach fresh leaves, tail to swish flies

lion-camouflages, large teeth and claws to kill

places with semi arid grassland climate

australia

ghana

central asia

sicily

tropical rainforest location

belt around equator, between Tropic of Cancer and Capricorn

south and central America , Africa and Southeast Asia

temperatures of tropical rainforest

stays around 20-25 degrees

highest temps in January

highest rainfall in October

long wet seasons

vegetation in tropical rainforest

liana vines-spread from tree to tree to reach sun in canopy

drip tips- help rainwater drain quickly to roots

buttress roots-large roots supporting tall trees to help absorb nutrients

animals in tropical rainforest

poison dart frog-poisonous

jaguar-camouflage

spider monkey-long tails to swing

places with tropical rainforest climate

ecuador

india

Cameroon

central africa

how are areas of high pressure created by global circulation

-air, which is heated at the equator and rises, cools and sinks at around 30° north and south of the equator, creating high-pressure zones associated with dry conditions. 

how are areas of low pressure created by global circulation

through the rising of warm, less dense air, which occurs at the equator and in other regions where solar radiation is intense, leading to unstable weather conditions. 

why is it hot at equator and cold at poles

less atmosphere to pass through t equator so more heat makes it to the surface

equator faces sun all year

depressions are

low pressure

anticyclones are

High pressure

global pressure systems

typical weather in low pressure areas

summer=prolonged rainfall, cloudy skies, storms

winter-storms, snow, heavy rainfall

typical weather in Hugh pressure areas

summer-calm, long sunshine periods, thunderstorms

winter-extensive fogs, very cold nights, cloudless skies

extreme low pressure weather

tropical cyclones-large rotating storms over oceans in tropical areas

• cyclones-violent tropical storms over India ocean

• hurricanes-violent tropical storm in caribbean region

• typhoon-violent tropical storm over Pacific Ocean

extreme High pressure weather

drought and heatwaves -prolonged dry periods of weather

global distribution of cyclone/hurricanes

often occur at start of American summer from end of June to October

how do cyclones form

sea temps must be 27 degrees weeks prior

• warm air rises rapidly, creating low pressure

• leads to condensation and development of towering cloud and torrential rain

• warm moist air moves in to replace the rising air and spirals upwards toward atmosphere

high pressure case study

California drought

low pressure case study

hurricane Haiyan in philipines