Topic 1: Hazardous Earth Flashcards
Its only the storm stuff and climate change stuff so far! REMINDER!!!! ADD TECTONIC STUFF
How does the Sun’s energy vary around the Earth?
Most direct = at the Equator
least direct= at the Poles
due to the tilt in the Earth’s axis!
How is the energy redistributed?
By pressure differences and ocean currents
How the atmospheric circulation
determines the location of arid (high pressure) and high rainfall (low pressure) areas?
The movement of air across the planet occurs in a specific pattern. The whole system is driven by the equator, which is the hottest part of the Earth. Air rises at the equator, leading to low pressure and rainfall. When the air reaches the edge of the atmosphere, it cannot go any further and so it travels to the north and south. The air becomes colder and denser, and falls, creating high pressure and dry conditions at around 30° north and south of the equator. Large cells of air are created in this way.
How do ocean currents work? (Using example of the Gulf Stream)
COLD water SINKS in the North Atlantic and forms a convection current so WARM water is drawn UP from the equator which too COOLS near Greenland and the cycle continues!
How do the land and sea heat up differently?
Land:
Summer = QUICK heating= air RISES = LOW pressure
Winter = QUICK cooling= air DESCENDS = HIGH pressure
Sea:
SLOW at heating and cooling so…
Summer = cool, DENSE air = HIGH pressure
Winter = hot, LIGHT air = LOW pressure
How is wind created?
When air moves from an area of HIGH pressure to LOW pressure!
What is the ITCZ?
The Inter Tropical Convergence Zone is an area of LOW pressure, which brings rain!
Moves within the tropics over the year = change in season/climate
What causes the ITCZ?
The ITCZ forms when trade winds of the Hadley cells converge and rise, bringing rain.
What are the Hadley cells?
Between 0 - 30 °
1) At the equator, the ground is intensely heated by the sun. This causes the air to rise which creates a low-pressure zone on the Earth’s surface.
2) When it reaches about 30° north and south, the air cools and sinks towards the ground forming the **subtropical high-pressure ** zone. As the air sinks, it becomes warmer and drier = an area of little cloud and low rainfall = deserts
3) Cycle is completed as air flows back to the equator as trade winds
What are the Ferrel cells?
Between 30 - 60 °
- flows in OPPOSITE direction to Hadley and Polar cells!
- affects areas such as the UK
- similar to the Hadley cells as when rising air converges, it brings rain.
What is Climate?
The seasonal pattern of weather changes brought by the world’s winds, ocean currents and pressure systems.
4 main theories for climate change in the past
- Eruption Theory
- Asteroid Collision theory
-Sunspot Theory
-Orbital change theory
What is the Eruption Theory?
Also state:
- its timescale
- affect on planet
-named example
The eruption theory suggests that as volcanic eruptions produces ash and sulfur dioxide, these gases rose to the stratosphere and reflected some of the sunlight back into space, cooling the planet.
-1-2 years
-COOLING
- Mount Pinatubo in 1991 (avg temp drop by 0.5)
What is the Sunspot Theory?
Also state:
- its timescale
- affect on planet
-named example
The sun has solar storms on its surface from time to time which produce bursts of heat. But these do follow a regular 11 year cycle of high activity vs low activity.
-A few hundred years
-WARMING
- the Little Ice Age ( very little sunspot activity)
What is the Orbital Change Theory?
Also state:
- its timescale
- affect on planet
-named example
The Earth’s orbit changes in 3 ways over time called the Milankovitch Cycles:
- The wobble (26,000 years)
-The tilt (41,000 years)
-The stretch (100,000 years)
-WARMING and COOLING by 2-6 C
(can cause glacial and interglacial periods!)
What is the Asteroid Collision Theory?
Also state:
- its timescale
- affect on planet
-named example
Big asteroid impacts can alter the Earth’s climate for 5-10 years as millions of tonnes of ash and dust would be blasted into the atmosphere!
-5-10 years (but only every 500,000 years)
- COOLING
-dino extinction?
How do Ice cores tell us about the past?
1) Layers of ice stacked on top of each other over time!
2) Air bubbles containing CO2 get trapped in them, which can then be take out and studied to determine temperatures at that time.
3) Very useful to learn about glacial and interglacial periods
How do Tree Rings tell us about the past?
Each ring in a tree’s trunk shows an year of growth, which can be used to determine past temps as in warmer, wetter tears a tree grows more.
How do Historical Sources tell us about the past?
Any historical drawings, diaries or newspapers.
These provide recent evidence and overall suggest that the climate changed every few hundred years but can often be inaccurate as people see things in different ways.
What is the greenhouse effect?
The natural process in which greenhouse gases in the earth’s atmosphere trap heat from the sun and warm the planet!
What causes the Greenhouse Effect?
The effect itself is completely natural as it is needed to keep the earth habitable but is being increased by the extra greenhouse gases produced by human activities such as burning fossil fuels, farming and agriculture
What is the evidence that global warming is happening? (name any 2)
- -> 0.85 C temp rise in 1880-2012
–> Thermal expansion eg between 1870-2010 = 210 mm sea level rise
–>Ten hottest years ever recorded are after 1998
–>Arctic ice halved in size between 1979-2012
Explain how human activities (industry,
transport, energy, farming) contribute to the enhanced greenhouse effect,
leading to global warming.
Industry = processing oil
Transport= burning fossil fuels
Energy = burning fossil fuels to create heat energy/ electricity
Farming = using fertilisers + cows make methane + deforestation
What to look for when interpreting a climate graph?
- mean temp
- range
- trends
-total - highest and lowest
What can increasing climate change lead to?
–> increased frequency of floods and droughts
–> stronger storms
–> sea level rise = coastal areas and islands at risk
What is predicted for the future of global warming?
By 2100 its is estimated that:
–> temp rise between 1.1 to 6.4 C
–> sea level rise of up to 1 metre
Why is it hard to predict the future of global warming?
Variation in factors such as population change, natural disasters, development of technology.
What is a cyclone? ( WHEEEEEE 🌀 🌪 can u tell im going cray cary )
A rotating system of clouds and storms that forms over subtropical waters
(cyclones are named and measured differently depending on wear they originate)
How do these cyclones form?🤔
1) A CONVECTION CURRENT forms above the surface of the water as hot air heated by the ocean rises
2) water vapour in the updraughts condenses into CUMULONIMBUS CLOUDS
3) the CORIOLIS EFFECT causes the air to spiral around the centre/eye (also due to the huge difference in air pressure between the storm and its surroundings!)
4) As it gets more HEAT and MOISTURE it gets bigger until it reached a landmass!
Now kids what is the recipe for cyclones? 😋 (hint: 3 ingredients!)
1) a still, warm ocean with a surface temp of >26.5 C for a long period of time (creates low pressure)
2) Strong winds in the Troposphere to draw the hot air upwards!
3) THE CORIOLIS FORCEEEE
- generated by the earth’s rotation
- NOT on the equator = no storm yipeeeee
What hazards do cyclones present? (name at least 3! 💦 💨🌊)
–> Strong winds (anywhere between 89-220 km/h)
–> Storm surges (tides are higher due to low pressure)
–> Intense Rainfall (basically alot like 1000 is normal)
–> Landslides
Describe
the seasonal global distribution of tropical cyclones (hurricanes and typhoons) including source areas and tracks
- Northern hemisphere = June - November
- Southern hemisphere = November - April
- More common in the North
- Most common in the Pacific, Atlantic and Indian oceans
- NOT on the equator
- Not found near the poles
- Mostly affect Asia, the Caribbean, USA and Australia
Explain why
some countries are more vulnerable than others, to the impacts of tropical
cyclones
**Cyclone Aila, Bangladesh**
**Superstorm Sandy, USA ***
Understand ways
in which the countries can prepare for, and respond to, tropical cyclones.
(weather forecasting, satellite technology, warning and evacuation
strategies, storm-surge defences)
