Topic 1 - Hazardous Earth Flashcards
Where is the most solar radiation received?
At the equator
Why is the most solar radiation received at the equator?
Due to the spherical shape of the earth, the atmosphere is thinnest at the equator and the distribution area of the solar radiation is larger at the poles whereas there is a smaller distribution area at the equator
What causes changes in temperature throughout the year?
The earths movement and tilt causes changes in temperature throughout the year,
What causes a low pressure zones?
When air is heated it becomes less dense and rises. As it rises it cools and clouds form. Because there is less air at the surface it is now a low pressure zone.
What causes a high pressure zone?
Once air cools it becomes more dense and sinks. It warms as it cools and leaves clear skies. Because there is more air at the surface it is now a high pressure zone.
What causes wind directions?
Winds are caused when air moves from high to low pressure areas as a result of heating and cooling. Because of the earths rotation wind is deflected to the right in Northern Hemisphere and to the left in the Southern Hemisphere. This is the Coriolis Effect
What is the Coriolis Effect?
Wind being deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere due to the Earths rotation.
How do atmospheric circulation cells explain how heat is transferred around the world?
Air is heated at the equator, as it is heated it becomes less dense and begins to rise. The warm air spreads out to 30N and 30S. As the air reaches 30N and 30S, it cools and condenses, sinking back down to the ground, forming a high pressure zone. As winds blow from areas of high pressure to areas of low pressure, trade winds may then bring the air back to the equator to be reheated and westerlies may take the air to 60N and 60S. At 60N and 60S, the warmer air meets the colder polar air and is therefore less dense than the polar air and begins to rise. The air then spreads out the poles or back to 30N and 30S. Cold air at the poles may then return to 60N and 60S being carried by polar easterlies
How do large ocean currents transfer heat around the world?
Surface currents are caused by winds from the Coriolis effect. These winds help transfer warmer water from the equator. Deep ocean currents also move water which is caused by differences in water density. This density difference is caused by saltier water at the poles due to water freezing. This looped process is called the Thermohaline Circulation.
What is the Thermohaline Circulation?
The process of ocean currents moving heat around the world
What are the circulation cells closest to the equator?
The Hadley Cells
What are the circulation cells between the tropics and the poles?
The Ferrell Cells
What are the most southern and northern circulation cells?
The Polar Cells
What features are common at High Pressure Areas?
Low rainfall, arid, rarely cloudy
What features are common at Low Pressure Areas?
High rainfall, often cloudy
What is the Permanent zone of low pressure called?
The Inter-Tropical Convergence Zone, ITCZ
What are the 6 natural factors that cause climate change?
Eccentricity, Obliquity (Tilt), Precession (Wobble), Asteroid Collisions, Volcanic Activity, Solar Output Variation
How does eccentricity cause climate change?
Approximately every 100,000 years the shape of the Earths orbit around the sun changes. This means that sometimes the earths orbit is more circular, making the earth warmer (interglacier) and sometimes the earths orbit is more elliptical making the earth cooler (glacial)
How does Obliquity cause climate change?
The earths poles are not perfectly at the top and bottom of the earth. The poles are rotated approximately 23.5* from a vertical position. This creates seasons north and south of the equator. Approximately every 40,000 years the angle of the tilt changes, this means that sometimes the Earth is tilted closer or further from the sun, this causes seasons to be less and more pronounced at different times.
How many degrees are the poles from a vertical position?
23*
How do Asteroid Collisions cause climate change?
When Large Cosmic material, such as asteroids, impact the earths surface they throw large amounts of dust up into the earths atmosphere. This can partially block solar radiation, causing global temperatures to cool and leading to glacial periods.
How does Volcanic Activity cause climate change?
Major volcanic eruptions eject large quantities of ash and sulphur dioxide into the earths atmosphere. These are spread around the earths stratosphere by high level winds. This can block some solar radiation and cause the global average temperature to cool, this can lead to a glacial period
How does Solar Output Variation cause climate change?
The suns output of solar energy varies in short cycles of about 11 years and larger cycles of several hundred years. Periods when solar output is reduced may cause the Earths climate to become cooler
How does Precession (Wobble) cause climate change?
As the earth rotates on its axis, it does not do so perfectly. The earth actually “Wobbles” on its axis rather than rotating perfectly. As this happens the direction the axis is facing changes. This affects our seasons and creates either greater or smaller differences between summer and winter. This occurs over a period of approximately 24,000 years.
What are the 3 pieces of evidence for natural climate change?
Tree Rings, Ice Cores, Historical Sources
How do Tree Rings provide evidence for natural climate change?
Every ring in a tree roughly shows a year of growth. Changes in shape and size of tree rings can show conditions during that year. Warmer and wetter weather can show greater growth as the distance between tree rings is larger. Cooler and drier weather can show thinner as there is less growth . Damage to the tree can show there was a forest fire, suggesting warmer, drier, arid seasons
How do Ice Cores provide evidence for natural climate change?
Ice contains bubbles from each year. Scientists analyse the bubbles from each layer to see how much CO2 they contain. Scientists can also learn about the temperatures for each year by measuring relative amounts of different types of oxygen atoms in water. Pollution and volcanic ash can also be trapped in the ice
How do Historical Sources provide evidence for natural climate change?
Old photos, drawings, written records, diaries and the records of of dates at regular intervals are often not very accurate because they where not intended to record climate. However, they can still give us some evidence of recent climate events.
What does the greenhouse effect prevent happening to the earth?
it prevents the earth turning into a frozen wasteland
What is the most abundant gas in earths atmosphere?
Nitrogen, 78%
Which 4 human activities are enhancing the greenhouse effect?
Agriculture, Energy, Transport, Industry
How does Agriculture cause the enhanced greenhouse effect?
Trees absorb and store CO2. However, population growth and demand for food has led to deforestation and clearing for cattle farming and rice paddies. Deforestation stops the absorption of CO2, this leaves more CO2 in the atmosphere. Trees release the CO2 when cut down. Furthermore, human activities, such as cattle farming, produce methane which is 21X more powerful than CO2.
How does Energy cause the enhanced greenhouse effect?
Burning fossil fuels release CO2 which is a greenhouse gas. The demand for electricity is increasing due to an increasing population. As the demand increases so does the supply of electricity which is mostly generated by burning fossil fuels. The increase in CO2 production, which has increased by 30% since 1850, enhances the greenhouse effect
How does Transport cause the enhanced greenhouse effect?
Most vehicles burn fossil fuels which then release greenhouse gases. Car ownership is rapidly increasing in developing countries, this means there are more cars on the road (especially in urban areas). This then means more greenhouse gases are being emitted. As people travel on planes more, the amount of flights increases. Planes emit nitrous oxide, the amount of nitrous oxide emitted has increased 16% since 1850 and is 250X as powerful as CO2
How does Industry cause the enhanced greenhouse effect?
As the amount of disposable income increases, so does the demand for consumer goods. This causes the industry to increase, The industry uses lots of energy and some of the industrial processes release greenhouse gases. When cement is produced lots of CO2 is produced, industrial waste decays and releases methane. Halocarbons are 3000X as powerful as CO2 and is used in solvents and cooling equipment.
What are the 4 pieces of evidence to prove human activity is enhancing the greenhouse effect?
Declining Sea Ice, Global Temperature Rise, Sea Level Rise and Warming Oceans, Extreme Weather Events
How does Declining Sea Ice provide evidence that human activity is enhancing the greenhouse effect?
The extent of Arctic sea ice is declining more and more every year. Every year sea ice melts in the spring then forms again in the winter when the ocean temperature falls below -1.8*C, however due to warmer global temperatures more ice has melted than ever before. By 2012 the amount of floating sea ice had shrunk to less than half of that in 1979, the extent of sea ice in winter has decreased by more than 3% per decade over the last 35 years. This sharp decline in the extent of sea ice cannot be explained by natural cycles indicating human interference . Boats are now able to travel through the northwest passage and northern sea route due to the lack of arctic ice, however this causes sea levels to rise.
How does Global Temperature Rise provide evidence that human activity is enhancing the greenhouse effect?
Global average temperatures have been rising steeply since the 1950’s, more rapidly than ever before. Temperatures have increased by 1C since 1880 and are expected to rise by 0.3 - 4.8C by 2100. Furthermore, the top 10 hottest years on record have all been since 1998. This shows that human activity increases global temperatures
How does Sea Level Rise and Warming Oceans provide evidence that human activity is enhancing the greenhouse effect?
Between 1870 and 2010 sea levels have risen by 210mm, there are 2 factors that caused this: Eustatic Sea Level Rise and thermal expansion. Eustatic sea level rise is when warmer temperatures cause glaciers to shrink and for ice sheets to melt. The melting of ice on land means that Water stored on land as ice in places such as greenland and antarctica melt and release water back into the ocean causing sea levels to rise. Thermal expansion is when the ocean expands due to it getting warmer, scientists estimated that this accounts for half of the measured rise in sea levels
How does Extreme Weather Events provide evidence that human activity is enhancing the greenhouse effect?
Since 1950 there has been a higher frequency of heat waves in many areas and fewer cold weather extremes. In the UK, more rainfall records were broken in 2010-2014 than in any decade on record, even after only half a decade. 2013 was one of the wettest years on record and December 2015 was the wettest month ever recorded in the UK
What are the possible consequences of Climate change?
Uninhabitable land, Lower Crop Yields, More extreme weather, Impact on Farming
What is the impact Uninhabitable land of on People?
Some areas could become so hot and arid they’re difficult or impossible to inhabit. Low-lying coastal areas could be lost to the sea or flood. This could lead to migration and overpopulation in other areas
What is the impact of Lower Crop Yields on People?
This could increase malnutrition, Ill Health and death from starvation (Particularly in lower latitude countries)
What is the impact of More extreme weather on People?
More money has to be put into predicting and reducing the impact from extreme weather events and rebuilding afterwards
What is the impact of Impact on Climate change on farming?
Some crops in higher latitude countries could benefit from warmer temperatures. However some crops could suffer, e.g maize crops have shrunk
What is the coriolis effect?
a strong force created by the earths rotation
What is the eye of the storm?
the centre of a tropical cyclone
What are characteristics about the eye of the storm?
clear sky and no wind
What is seasonal Distribution?
how something such as a tropical cyclone occur at different times of the year
What is the source area?
The region in which a tropical storm first forms
What is the Track?
the path followed by a Tropical Cyclone
Where is the source areas of Tropical Cyclones?
Between the tropic of capricorn and the tropic of cancer
How warm does the ocean have to be for Tropical Cyclones to form?
above 26.5*C
What is the Inter Tropical Convergence Zone?
an area of permanently low pressure where tropical cyclones commonly form
