Topic 1 - Hazardous Earth Test Revision Flashcards
Explain why low latitude locations receive more heat than places close to the poles
Locations closer to the equator receive more heat due to two factors. one of these is that sunlight is spread out much less at the equator than at the poles, locations at the equator have the sun overhead, spreading all the heat over a concentrated location, while at the poles, the sun is at a lower angle, and the same heat is spread out much more over the ground. additionally, the distance the suns light has to travel through the atmosphere is much less at the equator due to it being at less of an angle, at the poles however, the sun has to travel through much more of the atmosphere due to its rays coming in at an angle.
How is a high pressure area different to a low pressure area? How does the weather differ?
In low pressure areas, the air rises due to it being warmer than the other air surrounding it. In these areas, the warm air rises up, taking moisture with it, this moisture condenses and forms clouds, making the area of low pressure have rain. In areas of high pressure, the air is cold and sinks, creating an area of high pressure. The sinking air is heated by the ground, meaning it can carry more moisture, in areas of high pressure this means that there are clear skies with very little rain.
how does high and low pressure explain wind direction?
Winds are caused when air moves from high to low pressure across the earth’s surface as a result of different places heating and cooling. Because of the earths rotation, the wind is deflected to the right in the Northern Hemisphere and left in the Southern Hemisphere. This is called the Coriolis effect.
How do atmospheric circulation cells explain how heat energy is transferred around the world?
Atmospheric circulation cells work as there are differences in pressure at higher altitudes then at lower altitudes, this is created by air being heated and rising, creating higher pressure at higher altitudes, and lower pressure at lower altitudes, alternatively, when air is cooled, it creates higher pressure at lower altitudes, and lower pressure at higher altitudes. These differences in pressure are created at the equator, where air is heated by the sun and rises, and in the northern and southern hemisphere, where it is cooler and air is cooled down, causing it to sink. This can create a chain reaction, as high pressure hot air from the equator travels to the area of low pressure in the northern/southern equator, and on its journey is cooled down, causing it to sink, resetting the cycle, the now cool air sinks, creating an area of high pressure, which travels in the form of wind towards the area of low pressure near the equator, where it is heated and rises, thus continuing the cycle.
How do large ocean currents transfer heat around the world
Surface currents are caused by winds and help transfer heat away from the equator, eg the gulf stream brings warm water from the Caribbean and keeps Western Europe warmer than it would otherwise be.
There are also deep ocean currents driven by differences in density
When water freezes at the poles, the surrounding water gets saltier, increasing its density.
As it gets denser, it sinks, causing warmer water to flow in at the surface - creating a current
This warmer water is cooled and sinks, continuing the cycle
How do orbital changes cause climate change
Orbital changes are a variation of the way the earth moves around the sun. These changes may have caused the glacial and interglacial cycles during the quaternary period.
-Eccentricity is when the orbit of the earth changes shape over long periods of time, approximately every 100,000 years. This means that sometimes the earths orbit around the sun is more circular, making us slightly warmer, and sometimes the orbit becomes more eliptical, making the earth slightly cooler
- axial tilt: the angle of tilt changes every 40000 years, this means that sometimes the earth is tilted further or closer to the sun, changin the differences in season
- precession: as the earth rotates on its axis, it does ot do so perfectly, and wobbles, this changes the direction the axis is facing, meaning greater or smaller differences between summer and winter.
How do asteroid collisions cause climate change
Large cosmic material, such as asteroids and comets, can impact the earths surface. This can eject large volumes of dust into the atmosphere, partially blocking solar radiation and leading to glacial periods. It was this effect that is believed to have wiped out the dinosaurs.
How does volcanic activity affect climate change
Big volcanic eruptions can change the earths climate, big volcanic eruptions can produce ash and sulphur dioxide gas. If this gas gets high enough, it can be spread around the earth in the stratosphere by high level winds. The blanket of ash and gas will stop some light reaching earths surface, leading to climate change.
How do sunspots affect climate change
Activity with sunspots can affect how much energy is being given out, lots of sunspots means the sun is more active, less sunspots means it is less active. There is in general an 11 year sunspot cycle, but there have been times when there have been little sunspots for a long time.
How does agriculture cause the enhanced greenhouse effect
Agriculture is causing the enhanced greenhouse effect in multiple ways. When land is cleared to make way for agriculture, trees are cut down in massive numbers. It is these same trees which absorb co2, the most popular greenhouse gas, and when these trees are cut down, then this has an impact on the amount of co2 in our atmosphere, and hence has an impact on climate change. Also, Many agricultural processes release large amounts of greenhouse gas, for example, cattle produce methane when they pass gas, and rice paddies produce methane when flooded. Methane is 21 times more potent than co2, and as such when it is released enhances the greenhouse effect and has a negative impact on global warming.
How are human activities causing the enhanced greenhouse effect
Due to our growing population and the arrival of new technologies, our demand for energy is increasing. Most of the electricity that we use comes from burning fossil fuels, which produces co2 and releases it into the atmosphere. Co2 is a greenhouse gas, and as such when it is released into the atmosphere it enhances the greenouse effect and contributes to global warming.
How doestransport cause the enhanced greenhouse effect
Due to cars becoming affordable, and many people taking flights over long distances, huge quantities of fuel are being used, this is an issue as these types of transport nearly all rely on burning fuel, which releases greenhouse gasses. Into the atmosphere. With more and more cars taking the roads, congestion begins to become an issue, congestion causes problems because cars are having to sit with their engines on, which burns more fuel and releases more co2 into the atmosphere, enhancing the greenhouse effect and increasing climate change. These vehicles also produce nittrous oxide, a greenhouse gas 250 times more potent than co2, the use of transport has meant that nitrous oxide levels have risen 18% since 1850.
How do industrial processes cause the enhanced greenhouse effect
Industrial processes can require a lot of energy, and as such release greenhouse gasses through the energy used. Additionally, many industrial processes release greenhouse gasses on their own, for example the production of concrete produces co2, and some industrial processes can release halocarbons, which are 3000 times as potent as co2 as a greenhouse gas, this causes the enhanced greenhouse effect and contributes to climate change.
