Component 1 - Hazardous Earth Flashcards
What are the 3 cells?
1.Hadley
2.Ferrel
3.Polar
How does air move around the Earth due to cells?
1.The sun warms the Earth at the equator, which causes air to rise. This creates a low pressure belt. As the air rises, it cools and condenses and forms clouds and rain.
2.The cool, dry air moves out to 30° N and S of the equator
3.Here the cool air sinks, creating a high pressure belt, with cloudless skies and very low rainfall.
4.The cool air then moves as wind back to the equator, forming a Hadley cell, or towards the poles.
5.At 60° N and S of the equator, the warmer surface winds meet colder air from the poles. The warm air is less dense so is forced to rise, creating low pressure and frontal rain.
6.Some of the air moves back towards the equator, forming a Ferrel cell, some goes towards the poles.
7.At the poles, the cool air sinks creating high pressure. The high pressure air is drawn back to the equator as wind, forming a polar cell.
What is frontal rain?
rain that forms where the warm and cold air masses meet
What are trade winds?
surface winds which blow towards the equator
What are westerlies?
surface winds blowing towards the poles.
What is thermohaline circulation?
The cycle of cooling and sinking of water, which moves water around the earth in a big loop
How are surface currents made and what do they do?
- caused by winds
- They transfer heat away from the equator, eg the gulf stream
How do deep ocean currents work?
1.When water freezes at the poles, surrounding water gets saltier and denser
2.This makes it sinking, causing warmer water to flow in at the surface, creating a current
3.The warmer water cools, creating a cycle
How are arid climates made?
- Sinking air from the Hadley and Ferrel cells causes high pressure.
- This means rainfall is low, and termperatures are warm for most of the year.
How are polar climates made?
1.Sinking air from the polar cells creates an area of high pressure at the poles.
2.This means temperatures are low all year round and there’s very little rainfall.
How are tropical climates made?
1.Rising air from the 2 Hadley cells meeting causes low pressure.
2.This results in high rainfall and high temperatures all year round.
How has the Earth’s climate changed in the period before and during the Quarternary period?
- Before, it was warmer and quite stable.
- During, global temp has shifted between glacial periods, that last 100,000 yrs, and warmer interglacial periods, lasting 10,000 yrs
- The last glacial period ended 15,000 yrs ago, the Earth is currently warming
What are the 3 orbital changes which can change the climate?
1.Eccentricity - where the Earth’s orbit goes between circular and eliptical every 96k years
2.Tilt - where the Earth’s tilt changes angle over 41k yrs
3.Precession - where the axis of the Earth wobbles every 22k yrs
How do the 3 orbital changes affect the climate?
The cycles change the amount of solar radiation the Earth gets.
What are the 4 natural causes of climate change?
- Orbital changes
- Volcanic activity
- Solar output
- Asteroid collision
How does volcanic activity affect the Earth’s climate?
1.Major eruption eject large amounts of material like ash into the atmosphere
2.Some of these particles reflect the sun’s energy back into space, so the Earth cools
3.This causes a short term cooling in the climatge, eg - Mount Tambora in 1815, which led to the year without summer in 1816
How do asteroid collisions affect climate?
1.Asteroids hitting the Earth throw up huge amounts of dust into the atmosphere
2.These particles prevent the Sun’s energy from reaching the Earth, causing temperatures to fall for several years
How does solar output affect climate?
1.The sun’s output of energy changes in short cycles of 11yrs, and longer cycles of hundereds of years
2.Sunspot activity/solar flares result in more energy from the sun, raising temperatures/
What are 3 pieces of evidence for past climate change?
1.Tree rings
2.Ice cores
3.Historical records
How can we detect past climate change through tree rings?
1.The thickness of each ring depends on the climate that year
2.If it is warmer then the rings are thicker, else they’re thinner.
How can we detect past climate change through ice cores?
1.1 layer of ice is formed every yr in ice sheets
2.We drill in to the ice sheets to get long cores
3.By analysing the gases, eg CO2, trapped in the layers of ice, we can tell what the temperature was like that year.
How can historical records tell us about past climate change?
1.Since the 1850s global temp has been measured with thermometer
2.Historical diaries can show what the climate was like in the past, by giving the dates of harvests and days of rain/snow.
3.Paintings and news articles of fairs and markets on a frozen Thames show that winters in Europe were colder back then
What was the medieval warm period?
1.A period of relatively high temps between 900-1300AD
2.Harvest records show England was warm enough to grow large amounts of grapes
What was the Little Ice Age?
1.A period of cooling after the medieval warm period
2.Paintings from the 17th centure show the London Frost Fairs on the Thames.
3.Historical records show Arctic Ice reaching Scotland.
Radiation waves coming in are ____ and going out are _____
Radiation waves coming in are short and going out are long
What 4 ways are humans causing the enhanced greenhouse effect?
1.Farming
2.industry
3.Energy
4.Transport
What is the enhanced greenhouse effect?
Human activities causing global warming by making the greenhouse effect stronger
How does Farming cause the enhanced greenhouse effect?
1.Farming cows releases a lot of methane
2.Rice paddies emit methane from flooded fields
3.Trees absorb and store CO2. Deforesting for farming prevents this.
How does Industry cause the enhanced greenhouse effect?
1.Industry uses a lot of energy, to get this they burn fossil fuels, which releases greenhouse gases
2.some industrial processes, eg making cement from limestone, releases CO2
3.Industrial waste decays and releases methane
How does Energy production cause the enhanced greenhouse effect?
- CO2 is released into the atmosphere when burning fossil fuels
How does Transport cause the enhanced greenhouse effect?
- Most vehicles run on fossil fuels, which release greenhouse gases
- Car ownership has rapidly risen due to rapid development
- Increased congestion causes even more emissions
What 4 pieces of evidence is there to support the fact that humans are causing climate change?
1.declining arctic ice
2.global temp rise
3.sea level rise and warming oceans
4.extreme weather events
How does declining sea ice support human caused climate change?
- Sea ice forms in winter when ocean temps fall below 1.8°C.
- The extent of this ice has decreased 3% each decade over the past 35 yrs
How do global temp rises support human caused climate change?
1.Temps have increased by nearly 1°C since 1880, and ar expected to rise between 0.3-4.8°C between 2005-2100
2.The top ten warmest years have all been since 2000
How does sea level rise and warming oceans support human climate change?
1.Since 1901 sea levels have risen by 0.2m.
2.Glaciers melting and warmer water causes sea levels to rise
What is eustatic sea level rise?
- warmer temps cause glaciers to shrink and melt.
- The melting of ice on land then flows into the seas and causes it to rise
What is thermal expansion?
1.water in the oceans expands as it gets warmer, causing sea level rise
How do extreme weather events support human caused climate change?
- since 1905, there has been a higher freq. of heat waves in many areas, with less cold weather extremes
- In the UK, more rainfall records were broken between 2010-20 than in any other decade.
how does climate change impact people?
1.more deaths due to heat
2.more damage in coastal and low lying areas due to rising sea levels
3.many crop yields will fall, causing malnutrition
4.weather is getting more extreme, so more money must be spent to predict and protect
Why is there a lot of uncertainty around future climate change?
1.we don’t know how emissions will change as it’s hard to predict how population will grow and how governments will act and develop
2.we don’t know the exact climate changes each scenario will cause as we don’t fully understand the natural processes.
3.we don’t know what attmepts there will be to reduce human caused climate change
How do tropical cyclones develop?
1.they develop when the sea temp is 26.5° or higher and when the wind shear between higher and lower parts of the atmosphere are low
2.They form between 5-30° N and S of the equator, any further and the water is too cold.
3.Warm, moist air rises and condensation occurs, this releases huge amounts of energy making the storm powerful. The rising air creates and area of low pressure, causing high winds
4.The Earth’s rotation deflects the path of winds which causes the cyclone to spin ( coriolis effect)
5.The cyclone then travels towards the west because of the easterly winds near the equator
6.As it ventures away form the equator, they curve east because of westerlies
What causes cyclones to dissipate?
1.When they move over land or cooler water, their warm water energy supply is cut off so they weaken
2.Changes in windspeed from meeting other weather systems can also weaken cyclones
What is the structure of a cyclone?
1.The eye is up to 50km across and is caused by descending air. There’s very low pressure,light winds,no clouds, no rain and warm temps.
2.The eyewall is where there’s spiralling rising air, very strong winds, storm clouds and torrential rain and low temps
3.The edges of the cyclone is where the wind speed falls, clouds become smaller, rain becomes less intense and the temp increases.