Weather And Climate (the Right One) Flashcards
What is in constant motion?
The earths atmosphere
Why does the equator receive the most concentrated radiation?
Because the Suns Ray’s hit the surface closest to a right angle. This is the hottest part of the surface.
In polar areas, the sun’s rays hit the surface at a lower angle. Why is it colder?
Because there is a larger area to heat
As air is heated by the ground, it rises, causing what?
Low pressure
In places air sinks, causing what?
High pressure
What does differences in pressure cause?
It causes winds, which redistribute heat from the tropics across the planet
What is the Coriolis effect?
As the air moves above the surface of the earth, the planet continues to rotate. This means that is a mass of air moves north from the equator over a large distance, it will appear to have been deflected to the right and not travelled straight north. This is because the earth has rotated below the air, making it appear that the air has travelled in a curve. In the Southern Hemisphere, winds are deflected to the left.
Go to page 96
And look at the circulation cells
What is the movement of air within circulation cells controlled by?
It’s controlled by heating and cooling. The earth receives all of its heat from solar radiation from the sun. The radiation passes through the atmosphere and heats up the ground directly. As the ground heats up it warms the air above it, providing the heat in our atmosphere. As the earth is roughly spherical in shape, not all areas receive the same amount of radiation from the sun. This is because the surface of the planet is curved, therefore the radiation from the sun hits the earths surface at differing relative angles.
How do jet streams have an impact on air movement?
Jet streams form mostly at the boundaries of the main circulations cells (eg at the boundary of a polar cell and a Ferrel cell) where there is significant temperature difference. There streams can affect the movement of other weather systems and can therefore change the weather for different areas.
What are jet streams?
A fast-moving current of air in the upper atmosphere
What is a Ferrel cell?
A circulation cell that brings warm air towards the uk
What is a Hadley cell?
A circulation cell near the equator responsible for storms at the equator and desert belts north and south of the equator.
What is a polar cell?
The circulation cell furthest from the equator that brings cold air south towards the uk
What is oceanic circulation?
When oceans redistribute heat around the earth
What are surface ocean currents driven by?
By the movement of wind across the top of the water
What are deep ocean currents driven by?
By water sinking and rising as a result of temperature changes
What are both types of ocean currents deflected by?
The Coriolis effect
What do some ocean currents play a part in?
Some ocean currents play a part in heat redistribution include the Gulf Stream, which brings warm water from the Caribbean Sea across the Atlantic Ocean to the uk, and the Humboldt current, which takes cold water from the southern tip of chile north to Peru and supports a large amount of marine life.
What is climate change?
Climate change refers to how the average climatic conditions of the planet vary over time. At some points in our planets history the earth has been comparatively warm and during other periods it has been significantly colder. The planets history is divided into periods and the climate during the quaternary period has changed many times.
What is climate?
The average weather conditions of an area occurring over many years
What does climate change mean?
Variations in temperature and rainfall affecting the whole world
What is the quaternary period?
The current period of geological time
How can climate change occur?
Through both natural and human causes. Natural causes have been responsible for most climate change during the majority of the earths history, with human causes having a greater impact over the last 250 years compared with natural causes, particularly since the industrial revolution.
Describe natural causes of climate change?
There are several natural processes that can lead to climate change. One such process is milankovitch cycles. These are natural changes to the earths orbit and position that affect how much radiation we receive from the sun. Sometimes these cause us to receive more radiation than normal, resulting in global warming, and sometimes lead to us receiving less than normal, leading to global cooling.
What are the 3 types of milankovitch cycles?
Eccentricity, axial tilt, precession
What is the eccentricity cycle?
The orbit of the earth changes shape over long periods of time, approximately every 100,000 years. This means that sometimes the earth’s orbit around he sun is more circular, making us slightly warmer (interglacial), and sometimes the orbit becomes more elliptical, making the earth slightly cooler (glacial)
Describe the axial tilt cycle?
The earth does not sit with the north and south poles exactly at the top and bottom of the planet. In fact,nature earth is tilted so that the poles are actually rotated approximately 23 degrees from a vertical position. This creates our seasons north and south of the equator. However, over a period of approximately 40,000 years, the angle of the tilt changes. This means that sometimes the earth is tilted further away from the sun, which makes the difference in the season’s more pronounced (summers are warmer and winters are colder). When it is closer to the sun, the difference in the seasons is less.
Describe the precession cycle
As the earth rotates on its axis (which is what gives us day and night), it does not do so perfectly. In fact the earth wobbles on its axis, in a similar way to a spinning top as it slows down. 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.
How is solar variation a cause of global climate change?
The amount of radiation the sun produces over time. Periods of lower solar activity are likely to lead to glacial periods and those with higher activity lead to interglacial period
How is volcanism a natural cause of global climate change?
Large-scale volcanic eruptions can eject huge volumes of ash and dust into the atmosphere. Some eruptions can produce so much that the volcanic material can partially block our solar radiation, reducing temperatures and causing glacial periods
How is surface impact a natural cause of 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. Climate change is caused by surface impact can have dramatic effects on life. One such impact approximately 65 million years ago is considered to be responsible for the extinction of the dinosaurs. It is not the force of the impact that is thought to have wiped them out however, but rather the massive climate change that was created by the impact.
Trees live for hundreds of years, in some cases thousands, they can experience the impact of climate change. As trees grow they produce growth rings that can be seen in a cross section of a trunk. What can these growth rings tell us about climate change?
Growth rings tend to be wider in warmer, wetter climates and thinner in colder, drier climates. Analysing the rings can tell us what the climate was like throughout the trees history. However, while this is helpful, we can only get this data for the length of time the tree has been alive. To gather data from further in the past, we can use ice sheet cores
How can ice cores tell us about the history of climate change?
Ice cores are drilled sections of ice from sheets in locations such as Antarctica and Greenland. As snow falls it is compressed into ice layers and these layers capture information about the climate at yen time they were formed. This is because they can contain volcanic ash, microbes, pollen and even bubbles of air trapped when the ice formed. All of this can give invaluable information on past climates
How is pollen useful information about the earths climate change history?
Pollen is produced by all flowering plants and distinct shapes and structure of pollen allows us to identify which plant the pollen has come from. Pollen can become trapped in ice and in sedimentary rocks. Since certain plants can only grown in certain conditions, this gives us information a hit what the climate must have been like when the rock or ice in which the pollen was trapped formed.
What documents and we use to find out about historical climates?
Personal diaries and religious records. These documents include destroy ions of what the climate was like during the past
What is the greenhouse affect?
The green house affect is a natural process which keeps the earth warm. Greenhouse gases in the atmosphere, such as carbon dioxide and methane, trap some of the heat that is radiated from the surface which would otherwise have been lost in space. Without this effect, the average temperature of the earth would be much cooler
Human activity has resulted in a large increase in the human production of green house gases, leading to the enhanced green house affect and global warming. Describe all the green house gases
Industrial processes, transportation, agricultural by-products, fossil fuels, power stations, waster disposal and treatment, land use and biomass burning, residential, commercial, co2, methane , nitrios oxide
How does industry impact climate change?
As levels of disposable income rose, increased demand for the production of the consumer goods leads to industry growth and the need for more energy, resulting in more fossil fuels being burnt
How does transportation impact climate change?
With cars becoming more affordable and more people taking flights over long distances, huge quantities of fuel are used. Almost all transport relies on burning fossil fuels in some way, again increasing the amount of greenhouse gases released
How does energy impact climate change?
The demand for electricity is growing because of increasing population and new technologies. Most of out energy is produced through burning fossil fuels (coal, oil, natural gas), which produce greenhouse gases
How doe farming impact climate change?
Population growth has led to a higher demand for food production. Mechanisation means more fuel is burnt, and intensive farming of cattle and rice repost in increased production of methane, which is a greenhouse gas.
How does climate change impact food production?
Plants are able to produce there own food through photosynthesis. Animals eat plants (herbivores) or other animals haven eaten plants (carnivores) or they eat both plants and animals. This makes plants a vital source. Photosynthesis is a complicated process and can be negatively affected by increases in temperature or decreases in sunlight, both of which can occur because of global climate change. With lower crop yields, large sections of the population could suffer from malnutrition, a problem what will be worse in developing countries.
What is the most commonly known impact of climate change?
A likely rise in sea level. An increase in temperature will result in sea level an increase in temperature will result in land-based ice, particularly in the continent of Antarctica, melting and adding to the amount of water in the oceans.
What is thermal expansion?
It’s another cause of sea levels to rise. Warm water occupies a greater volume than colder water. A rise in global temperatures will cause the oceans to expand in volume, further adding to sea level rise.
The Maldives is a country located in the Indian Ocean which is made up of nearly 1200 small coral islands. The Maldives is the flattest country on earth, the highest point being only 2.4 meters above sea level. How much is it predicted that global sea levels will rise before the end of the century?
It varies from 20cm to more than 1m. This puts large areas of the Maldives at serious risk. As a developing country, the Maldives relies heavily on tourism. The main attractions of the islands are its sandy beaches, clear seas and coral reefs teeming with fish. Almost all of the country’s infrastructure is under threat from sea level rise. Eg, the country’s international airports, vital to the tourism industry are built 50m of the coastline
How is the Maldives responding to the threat of sea level rise?
With plans to migrate the impacts on the country. These include increasing rainwater harvesting to reduce reliance on groundwater supplies as well as trying to protect the groundwater supples from sea water infiltration to higher levels. The possibility of mass migration away from the country has also been discussed.
What are the social impacts of sea level rise on the Maldives?,
Higher sea levels and more regular storms lead to periodic flooding of coastal areas. In 2007, more than 1600 people had to be evacuated because of coastal flooding.
What are the economic impacts of the sea level rise in the Maldives?
The key attractions of beaches and coral reefs will become inaccessible, leading to a loss of employment in tourism. Cost of evacuations and rehousing will continue to increase.
What are the environmental impacts of the sea level rise in the Maldives?
Groundwater supplies are contaminated with sea water flowing into the islands. The soil is also contaminated. Temperature increases in the surrounding ocean may lead to bleaching and death of the islands coral reefs
Describe retreating glaciers
Glaciers and ice sheets account for most of the land-based ice around the world, as well as approximately 10% of the planets total land area. With increasing global temperatures, many glaciers are showing a pattern of retreat, meaning they are becoming smaller, and ice sheets are thinning
Describe the consequences of melting ice sheets
Melting of high mountain glaciers such as those in the Himalayas upon which farmers in India and Pakistan rely for irritation water, can lead to flooding of the local area in the short term. However, in the long term, with a smaller volume of ice available in the glacier, there may be water shortages because less water is produced by the glacier on a regular basis. On a global scale, melting ice sheets will add more water to oceans, leading to sea level rise
Where is the uk located?
Between 50 and 60 degrees N of the equator. Distance from the equator has an impact on climate: locations further north and south from the equator receive less solar radiation than areas closer to the equator. The uk’s climate is best described as temperature. Extremes of weather are uncommon and extreme weather events such as tornadoes and prolonged droughts are rare. As a result of the meeting of major air masses over the uk, particularly cool air from the north and south, frontal rainfall is quite common throughout the year
What is frontal rain?
A front in the boundary between air masses.mis moist air rises along the front, as the air cools clouds form and rain may fall
Describe the medieval warm period
The medieval warm period occurred between approximately 950 and 1100. During this period, the temperatures in the uk were high enough to support the growth of grape vines as far north as York and also allowed greater crop yields across the uk. The population increased significantly beat sue of milder winters and a greater availability of food. This period has been attributed to increased solar activity and possible period of low volcanic activity across the world.
What was the little ice age?
The little ice age was the period between the medieval warm period and the modern climate, between 1600 and 1850, when temperatures in the UK were low enough for the river Thames to freeze to a sufficient thickness for people to walk on. The extended winters caused widespread crop failures. This period has been attributed to some extreme volcanic eruptions as well as a decrease in solar activity
