Weather And Climate Flashcards
What is weather?
The condition of the atmosphere in a certain place at a certain time.
What is climate?
Climate is the average weather conditions in an area over a long period of time.
What is climate change?
Climate change is a large-scale long-term shift in the planets weather patterns or average temperatures.
What is global warming?
Global warming is the gradual rise in Earth’s temperature over time.
What is the greenhouse effect?
The process of greeenhouse gases trapping heat in the Earth’s atmosphere.
What elements make up the weather?
- precipitation
- wind speed
- air pressure
- temperature
- thunderstorms
What is temperature recorded with?
Thermometer
What is rainfall recorded with?
Rain gauge
What is air pressure measured with?
A barometer
What is wind direction measured with?
A wind vein
What is wind speed measured with?
An anemometer
If the wind is moving north east what is it?
Sout Westerly
What is temperature measured in?
°C
What is rainfall measured in?
mm
What is air pressure measured in?
Milibars
What is wind direction measured in?
N, E, S, W
What is wind speed measured in?
Mph / knots
What is sunshine measured in?
UV
What is cloud cover measured in?
Oktas
What is the greenhouse gas effect?
- Solar energy (short wave), emitted by the sun, enters the Earth’s atmosphere.
- A small amount hits dust and water droplets and is reflected back into space.
- Most of the solar energy that enters the atmosphere heats tge Earths surface.
- Long wave heat energy is radiated by the Earth back into the atmosphere.
- Some escapes beyond the atmosphere into space.
- Long wave energy is easily absorbed by the atmosphere, trapping heat.
What is a glacial period?
A period where there is significant ice coverage throughout the world and a cooler climate.
What is an inetrglacial period?
A period of warmer climate where the majority of ice cover has melted. These are shorter than glacial peiods.
Why are CO2 emmissions bad?
It strengthens the greenhouse affect, as the gas is able to absorb and trap heat in the atmosphere.
How are humans adding CO2 to the atmosphere? (4)
- agriculture - livestock rearing
- destruction and burning of forests
- burning fossil fuels
- transport (emmisions)
What is a natural cause of climate change?
Volcanic eruption
How do volcanic eruptions cause climate change?
Ash and gases released intonthe atmosphere reflect radiation from the sun back into space.
What is an eruption you have learnt about that caused the climate to change?
Mount Pinatubo erupted in 1991
How did Mount Pinatubo change the climate?
It ejected sulphur dioxide and ash particles into the atmosphere that reflected solar radiation back into space. The gas absorbed infrared radiation emmited from the Earth, preventing it from continuing the warm the Earth.
What was the overall effect of Mount Pinatubo?
It cooled the Northern hemisphere
What is another cause of natural climate change?
Milankovich cycles
What are the three cycles involved in the Milankovitch cycle?
- Eccentricity
- Precession
- Obliquity
What is eccentricity?
The shape of the earth’s orbit from circular to egg shaped every 100,000 years.
How does eccentricity affect the climate?
This alters the amount of solar radiation and heat reaching the Earth as variations in the shape of the orbit changes the distance the Sun is from the Earth.
What is precession?
The Earth completes a wobble on its axis every 26,000 years
How does precession affect the climate?
It controls which hemisphere is tilted towrd the sun, affecting the intensity of seasons as it changes the strength of solar energy on various points of the earth.
What is obliquity?
The tilt of the axis between 22 - 24.5° every 41,000 years.
How does obliquity affect climate?
It alters the energy of solar radiation recieved at different latitudes, having an increasing effect with distance form the equator.
Draw and annotate a diagram of how volcanic eruptions affect climate
Look in booklet
What is the evidence for climate change? (7)
- ice cores
- CO2 levels
- tree rings
- animal migration
- freak weather events
- average global temperatures
- melting ice
Draw a diagram of how air moves in high pressure?
Look in booklet
Draw a diagram of how air moves in low pressure?
Look in booklet
What is high pressure?
When air sinks from high in the atmosphere to ground level
What is low pressure?
When air rises and cools and condenses forming clouds
What is the ITCZ?
The intertropical convergence zone is a band of low pressure around the equator
Describe how air moves around the equator? (4)
- The sun is concentrated around the equator, warming the air so that it rises in an area of low pressure.
- The air reaches the tropopause then spreads out towards the poles.
- At about 30° north and 30° south the air sinks and creates an area of high pressure. Here the weather is dry.
- Air circulates back towards the equator in the lower atmosphere, creating trade winds.
What is an ice core?
A cylinder of ice drilled out of an ice sheet or glacier.
What does an ice core show?
The bubbles inside reveal atmospheric gas concentrations of when it was formed. These can be compared to present day.
How are ice cores evidence for climate change?
Ice cores from Antarctica show that carbon dioxide levels have increased 250 times faster from human activities than it did from natural causes after the last ice age.
How are temperature recordings evidence of climate change?
Records that start in 1880 show that the Earth’s average temperature has been increasing at an increasing rate.
How are CO2 levels evidence of climate change?
CO2 levels in the atmosphere are rising, enhancing the greenhouse affect. As CO2 increases so does average temperatures.
How is animal migration evidence of climate change?
Animals are forced to migrate to access the temperatures they require. Cod are migrating from their warming oceans futher north.
How is melting ice evidence of climate change?
As global temperatures rise so does the reate of melting ice. The antarctic ice sheets have decreased in mass.
How are freak weather events evidence of climate change?
Human caused climate change leads to increased freak weather evnts such as storms and storm surges.
How does carbon enter the atmosphere? (3)
- burning fossil fuels
- animal and plant respiration
- decomposers release carbon from dead animals and plants
When is carbon absorbed from the atmosphere?
- its absorbed by plants for photosynthesis
How do plants transfer carbon to animals?
Animals feed on plants passing carbon along the food chain.
What is the Keeling curve?
A general increase in CO2 levels that also fluctuates.
Why does the Keeling curve fluctuate?
Due to seasonal variation. Around October plants decompose, releasing more CO2 in the atmosphere while around May plants grow and absorb CO2 for photosynthesis.
When does the ITCZ move?
It moves according to time of year. In july it moves toward the northern hemisphere while in january it moves toward the southern hemisphere.
Why does the ITCZ move?
Because of the tilt of the Earth’s axis at different times of the year.
What are two low pressure weather impacts?
- Monsoon
- Cyclone/hurricane/typhoon
What are monsoon rains?
Heavy rains occurring when the prevailing wind in South East Asia blows from southwest in summer. This leads to distinct wet and dry seasons in many areas in the tropics.
What is an example of a monsoon you have studied?
South Asian Monsoon 2015
What places in particular did the south Asian monsoon affect?
India and Pakistan
What were the social impacts of cyclone Pam? (5)
- schools closed
- loss of life - people drowned
- displacement
- communication was broken with roads being out of use
- sanitation didn’t work - disease spread
What were the economic impacts of the south Asian monsoon? (5)
- houses destroyed
- schools had to be repaired
- crops destroyed
- government had to pay to repair damage
- cost of deploying help
What are the environmental impacts of the South Asian monsoon? (3)
- submerged farmland
- alluvium from the monsoon is fertile increasing future crop growth
- regrowth and repair can take longer than an annual flood cycle
What causes the monsoon rains in South East Asia?
The rains are formed as the ITCZ moves northwards across India in July. Because this is a low pressure area heavy rains occur.
What other weather event do monsoon rains cause?
Flash floods
Why did the South Asian monsoon 2015 cause flash floods? (3)
- The rain fell on dry, hard earth that could not absorb water and there are many steep slopes
- Urbanisation reduces infiltration
- Deforestation for farmland reduces interception
These all increase surface runoff
What is a cyclone/hurricane/typhoon?
A tropical storm that has high winds and heavy rainfall that are dangerous. Those with wind speeds from 39 - 73 mph as classified as tropical storms.
What is a cyclone that you have learnt about?
Cyclone Pam 2015
What area did cyclone Pam affect?
Island Vanuatu in the pacific
What were the social impacts of cyclone Pam? (5)
-homes were destroyed
-eleven people lost their lives - many injured
-people were displaced
- water supplies that villages rely on were severely damaged
- schools closed
What were the economic impacts of cyclone Pam? (5)
- crops ruined
- homes had to be repaired
- Australia donated over £30 million of aid
- water supplies had to be repaired
- cost of medical care
What is drought?
A prolonged period of abnormally low rainfall, leading to a shortage of water.
Where do the majority of droughts occur?
Along the Tropic of Cancer and the Tropic of Capricorn
Why do droughts occur along the tropics?
The Hadley cells cause high pressure along the tropics
What weather conditions does high pressure bring?
Little wind and precipitation
What is an example of a drought you have studied?
California drought 2015
What caused the 2015 California drought?
Low winter rainfall caused by the position of the jet stream.
What are the social impacts of the Californian drought? (5)
- 29 deaths
- risk to homes fire
- 20% decrease in personal water use
- West Nile virus spread to 798 people by mosquitos
- crops were destroyed causing food shortages
What are the economic impacts of the Californian drought? (2)
- government spent 20 millions dollars for water emergencies
- 2.7 billion loss in revenue including wages, transport and processing
What were the environmental impacts of the Californian drought? (4)
- poor air quality - increased dust
- wildfire risk damages habitats
- national parks closed
- groundwater supplies shrunk
How could agriculture industries respond to the drought? (2)
- grow less thirsty crops
- report plans to reduce water consumption to the government
How could energy and water industries respond to the drought? (4)
- reduce reliance on hydroelectric
- invest in solar and wind
- increase water prices
- leaflets on conserving water
How could government and law enforcement respond to the drought? (3)
- compulsory water restrictions
- fines
- hold back water to protect delicate ecosystems
How could everyday people respond to the drought? (3)
- voluntary water conservation programmes
- speeches
- encourage reduction is household water usage
What air mass brings warm air?
Tropical
What air mass brings cold air?
Polar
What air mass brings wet air?
Maritime
What air mass brings dry air?
Continental
Where does the tropical air mass come from?
South
Where does the polar air mass come from?
North, east and west
Where does the maritime air mass come from?
Over oceans
Where does the continental air mass come from?
Land masses
What air mass hits the UK at N?
Arctic/polar
What air mass hits the UK at NE?
Polar continental
What air mass hits the UK at SE?
Tropical continental
What air mass hits the UK at SW?
Tropical maritime
What air mass hits the UK at NW?
Polar maritime
What weather does polar maritime bring?
Cold and wet - cool conditions in summer and rainy/snowy in winter
What weather does polar continental bring?
Cold dry - settled, hot summer and cold, dry winter
What weather does tropical maritime bring?
Hot wet - warm, rainy summer and milder conditions in winter
What weather does tropical continental bring?
Hot, dry weather
How does latitude affect temperature?
The closer a place is to the equator the warmer it is
Why is it warmer at the equator?
The sun’s heat is more concentrated onto a smaller area of land at the equator so it is hotter here.
How does continentality affect temperature?
Coastal areas have a smaller annual temperature change than inland areas
What is continentality?
Distance from the sea
Why do coastal areas have a smaller annual temperature range?
Oceans are less dense than land. They absorb heat slower and retain this heat longer. In winter coastal areas are warmer from stored heat from the sea. In summer coastal areas are cooler as heat is lost to the sea.
Why do inland areas have a higher annual temperature range than coastal?
Land is more dense than water so it absorbs heat quicker and releases heat faster. In the summer inland areas are warmer as they absorb heat quickly. In the winter they are colder as there is less sea to heat the land.
Why are mountains cooler than lowland areas?
Altitude
What is the lapse rate?
Temperature decreases 1°C for every 100 meters of height above sea level.
Why are higher altitude’s cooler? (2)
- Air pressure here is lower so less heat is retained
- Temperatures are higher near the ground surface because of radiation
How does altitude affect rainfall?
Hilly areas receive more rainfall than flat.
What area of Britain receives more rainfall?
West Britain receives more rainfall than East.
How does relief rainfall form? (4)
- Prevailing winds bring warm, moist air off the ocean
- The air is blown inland and is forced to rise by things such as hills.
- As it rises it cools and condenses forming clouds.
- This causes relief rainfall on the windward side of the hill. A dry ‘rain shadow’ is created on the leeward side of the hill where air descends.
What is aspect?
The direction in which the land or slope is facing.
What is an example of aspect?
South facing slopes face the sun in the Northern Hemisphere and so are warmer.
What is the jet stream?
A strong ribbon of wind that circulates the globe and separates cold, polar air masses and warmer, tropical air masses.
How does the jet stream affect the UK?
It crosses over the UK
- when it takes a Northerly track, Westerly of the UK it brings high pressure, dry, settled weather
-if it stays in the same position , the UK will have a long spell of similar weather
Where do anticyclones form?
Where air descends (high pressure)
What is an anti-cyclone? (4)
- Air descends increasing the pressure on the Earth
- Very light winds blow outward from the centre, clockwise
- Descending air warms and so does not release condensation
- Few clouds form - weather is fine and dry
What is a depression?
Cells of low pressure that bring wind, cloud and rain.
How do depressions develop? (4)
- Over the Atlantic polar maritime air meets tropical maritime air. Where they meet is called a front.
- The air masses do not mix and the tropical maritime air is forced to rise as it is less dense
- The moist air condenses forming clouds that cause precipitation.
- Winds move the depression from West to East across the UK.
What three parts is a depression made of?
-The warm front
-The warm sector
-The cold front
What is the warm front? (3)
- The polar maritime air meets the tropical maritime air
- The tropical maritime air is warmer and less dense so is forced to rise
- The moist air condenses forming clouds that cause precipitation
What is the warm sector?
A period of clear and dry weather dominated by the tropical maritime air.
What is the cold front?
- The advancing cold air undercuts the warm air.
- The warm air if forced to rise quickly, forming clouds and precipitation.
What is a microclimate?
The climate of a very small or restricted area which differs from the climate of the surrounding area.
Why are cities warmer than rural areas? (3)
- dark coloured buildings, streets absorb heat
- human activity such as cars and factories
- fewer green spaces reduces cooling by transpiration
Why does it rain more in cities?
They are warmer causing air to warm and rise. This then cools and condenses forming clouds and precipitation.
Why are gusty winds stronger in urban areas?
Wind is funnelled between buildings, increasing its strength.
What factors affect weather in the UK? (6)
National scale:
- air masses
- latitude
- continentality
Local scale:
- altitude
- relief rainfall
- aspect
