Weather Hazards and Climate Change

Question 1

What is global atmospheric circulation

Answer 1

• sinking air forms areas of high pressure, surface winds move outwards from these areas
• Rising air forms areas of low pressure. Surface winds move towards these areas of low pressure
• surface winds are distorted by the Earth’s rotation, known as the coriolis effect
• The patterns of pressure belts and winds are affected by seasonal migration of the thermal equator

Question 2

Hadley cells

Answer 2

• stretch from the equator at latitudes 30N and 30S
• at the equator the trade winds from each hemisphere meet. the warm air rises rapidly causing thunderstorms
• the air at the top of atmosphere moves 30N and S where it becomes cooler and sinks to earths surface
• as it descends moisture is evaporated
• This creates high pressure areas with cloudless skies - hot deserts
• on returning to the ground some of the air returns to the equatorial areas of trade winds

Question 3

Ferrel cells

Answer 3

• 30N and S to 60 N as S
• winds collect moisture as they blow over earth surface
• at 60N and S they meet cold air from the poles
• The warm air rises over the cold air as it is less dense this produces low pressure systems known as the depressions
• some air returns to the tropics and some is diverted to the poles as part of the polar cells

Question 4

Polar cells

Answer 4

• These stretch from latitudes 60N and S to the N and S plates
• the air sinks over the poles producing high pressure
• the air then flows towards the low pressure in the mid - latitudes about 60N and S
• it then meets the warm air of the ferrel cells

Question 5

What is the polar front jet stream

Answer 5

• formed when cold polar air meets warm tropical air high above the atlantic ocean
• this normally occurs between latitudes 40 and 60N and 40 and 60S
• the exact location does vary
• this occurs at the division between the polar and ferrel cells

Question 6

what is the subtropical jet stream

Answer 6

• a generally in a westerly direction
• can be found at approximately 25N and 35S

Question 7

definition of a jet stream

Answer 7

• in upper atmosphere wind blows around the earth in a westerly direction
• within these winds there are bands of extremely fast moving air known as jet streams
• these are found at altitudes of around 10,000m

Question 8

The Milankovitch cycle - eccentricity

Answer 8

• the earths orbit changes shape due to the gravitational pull of other planets on the earth
• when the earth is closer to the sun the orbit of the earth is more circular. this means that interglacial periods are more likely
• the shape of the earths orbit around the sun changes from being a circle to an ellipse and the back again
• this takes around 100,000 (96,000) years

Question 9

The Milankovitch cycle - precession

Answer 9

• the earths axis wobbles like a spinning top over a cycle of 26,000 years
• the earths axis wobble can impact the seasons. specifically warmer summers are likely when the earth is closer to the sun on its wobble and this can cause rising temperatures
• the earths axis wobble is caused by the gravitational action of the sun and the moon

Question 10

The Milankovitch cycle - axial tilt

Answer 10

• it takes 41,000 years for the earths axis to change from 22.1 degrees to 24.5 degrees and back again
• when the earths axis is at a greater tilt, there will be more extreme seasons on a global scale = higher average temperatures = interglacial periods
  this is also known as obliquity

Question 11

solar variation

Answer 11

• the amount of energy that the earth receives from the sun is not constant. sometimes the earth receives more energy and sometimes less
• these changes are very small and hard to detect but connected to the ideas of sunspots
• number of sunspots increases from minimum to maximum over a period of 11 years - called a sunspot cycle
• more sunspots - more heat and opposite

Question 12

what are the key sources to knowing how the climate was in the past

Answer 12

• tree rings
• ice cores
• historical records
• pollen

Question 13

tree rings

Answer 13

• as trees grow they produce growth rings
• as trees grow for a very long time we can see the different rings from many years ago
• rings tend to be wider in warmer and wetter climates and thinner in colder and drier climates

Question 14

ice cores

Answer 14

• drill into ice 1.5 m at a time
• can drill ice cores that are hundreds of m down
• over 20,00 year old ice
• analyse ice bubbles of ancient atmosphere and greenhouse gas levels

Question 15

historical records

Answer 15

• people and portraits, diaries and religious documents and these include what the climate was like

Question 15

pollen

Answer 15

• pollen is produced by all flowering plants
• the distinct shape and structure helps us to know which plant it comes from
• pollen can become trapped in ice and sedimentary rocks
• certain plants can only grow in certain conditions, this gives us information about what the climate was like

Question 16

definition of the enhanced greenhouse effect

Answer 16

• this phenomena in commonly referred to as climate change or global warming.
• it is the impact on the global climate of the increased amounts of carbon dioxide and other greenhouse gases that humans have released into the earths atmosphere which traps too much heat since the industrial revolution

Question 17

definition of methane

Answer 17

• methane (CH4) is a hydrocarbon that is a primary component of natural gas.
• methane is also a natural gas so its presence in the atmosphere affects the earths temperature and climate system.
• methane is emitted from a variety of human influence sources such as cattle and rice farming.
• methane is 28 times more potent than carbon dioxide (CO2)and trapping heat in the atmosphere over a 100 year period

Question 18

what are the different sources of greenhouse gases

Answer 18

• industry
• transport
• energy
• farming

Question 19

industry

Answer 19

• industrial processes contribute to the enhanced greenhouse effect
• as levels dispose income rise, increased demand for the production of consumer goods leads to industry growth and the need for more energy , resulting in more fossil fuels being burnt

Question 20

transport

Answer 20

• most forms of transport use fossil fuels to power them
• 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, increasing the amount of greenhouse gases released

Question 21

energy

Answer 21

• power generation accounts for 25% of global carbon dioxide emissions
• the demand for electricity is growing because of population and new technologies. most of our energy is produced through burning fossil fuels which produce greenhouse gases

Question 22

farming

Answer 22

• farming contributes to greenhouse gases in a number of ways. The main contributor is methane
• population growth has led to a higher demand for good production.
• mechanisation means more fuel is burnt and intensive farming of cattle and rice results in increased production of methane, which is a greenhouse gas

Question 23

relief rainfall

Answer 23

• winds blow across the Atlantic ocean, they are warm as they have come from closer to the equator. as they blow across the ocean they pick up moisture
• when air reaches mountain it is forced to rise up over the hills. as it rises it cools (approx 1C for every 100m) cool air can’t hold as much water than warm air
• this means that the water vapour condenses and this forms clouds. rain falls over the mountains
• as the air passes over the mountains it starts to heat up again. this means it can hold more moisture again

Question 24

tropical cyclone facts

Answer 24

- form over tropical and subtropical oceans between the tropic of cancer and the tropic of capricorn - need water in temps over 27C to form - usually form end of summer and in autumn - highest number of cyclones occur in north pacific ocean - feature strong wind, heavy rain, often thunderstorms - typically move east to west with the trade winds

Question 25

definition of a source area

Answer 25

where tropical storms start their development

Question 26

the formation of a tropical cyclone

Answer 26

1. when warm and wet tropical sea air rises it condenses to form clouds, heavy rainfall, creates low pressure zone near surface of water 2. rising warm air causes the pressure to decrease at higher altitudes. - warm air moves towards the space occupied by the colder lower pressure air. low pressure sucks in air from warm surroundings which then also rises. - continuous upflow of warm and wet air continues to create clouds and rain 3. air that surrounds a low pressure zone at the centre flows in a spiral at very high speeds - anti-clockwise in the northern hemisphere 4. air is ejected at the top of the cyclone and falls outside of the storm away from the eye. - it reduces the mass of air over the eye of the storm causing wind speed to increase 5. the faster the winds blow the lower the air pressure in the centre and so the cycle continues. grows stronger 6. as it moves inshore their power gradually reduces because energy comes from sucking moist air up

Question 27

what is the coriolis effect

Answer 27

a phenomenon that causes fluids like water and air to curve as they travel across or above earths surface

Question 28

what are the main tropical cyclone causes

Answer 28

high winds intense rainfall storm surges coastal flooding landslides

Question 29

high winds

Answer 29

- cyclones produce winds of over 119km per hour. - these winds can cause severe damage to buildings. - trees can be uprooted and some smaller constructions become dangerous as they impact people and buildings - damage , injury loss of life

Question 30

intense rainfall

Answer 30

- as cyclones move over the ocean they take up a large amount of water and this results in a large release of rain. - weather forecasters can estimate how much rain may fall based on how fast the storm has been travelling over water. - the intense rain created by the tropical cyclone can lead to flooding, damage to property and injury

Question 31

storm surges

Answer 31

- cyclones create a large area of low pressure which allows the level of the sea to rise. - when combined with high winds produced by the storm a large mass of water can be forced towards and the the strength of the winds. - when the surge hits land it does so with severe force. - storm surges can erode beaches, coastal habitats, damage coastal defences and flow inland contaminating farmland.

Question 32

coastal flooding

Answer 32

- the combination of intense rain and storm surges puts coastal areas at severe risks of flooding - people and property also affects farming and tourism industry. - environmental impact of flooding by salt water will also be very damaging

Question 33

landslides

Answer 33

- intense rainfall affects areas at high relief as well as coastal lowlands. - high levels of rain can saturate the soil very quickly. makes soil heavy and steep slopes - soil can no longer be able to hold its position and will slide down slope. - deforestation can make slopes unstable and where underlying rocks is impermeable, the wet soil and rock above can easily slide over it and downhill.

Question 34

what were the impacts of hurricane sandy (case study)

Answer 34

social: - 150 people were killed - transport links were closed or faced severe delays - schools were closed for several days - many businesses were damaged, people could not go to work - petrol was in short supply - new york marathon was cancelled and this impacted upon tourist revenue -millions were left without electricity for many days economic: - new york stock exchange forced to close because of loss of power - total property damage estimated to be around 65 billion dollars environmental: millions of gallons of sewage were released into the waters arounds new york and new jersey - several coastal nature conserves were damaged by the storm surges

Question 35

what were the impacts of hurricane haiyan (case study)

Answer 35

social: - 6000+ confirmed dead with many missing therefore people lost family and friends - cost of the damage equals 2 billion therefore a lot of money would need to be given for people to rebuild their homes - foreign aid agencies were able to provide support for the effort therefore people wouldn’t starve. They could be safe - tens of thousands were homeless therefore they were unsafe as they are nowhere to sleep - Transport across the island by disrupted making provision of aid and support disrupted - Several areas were evacuated used the chemical leaks from damage industrial facilities therefore the water was polluted - there was lots of law and order as people panicked and they had no communication or support therefore looting to place Environmental: Power was cut off. The islands of many areas were isolated by the debris or landslides prevent preventing them from aid. - The mangroves of the East Coast were damaged and thousands of trees were uprooted therefore there was not as much coastal protection at the coast - A tanker fell so there was an oil spill therefore water was polluted and can carry diseases

Question 36

Responses to hurricane Sandy

Answer 36

Individual: - People posted images on social media which provided real time data of the worst affected places - Community support each other and helps with rescue and rebuilding - Blood was needed and many people donated Organisation: - Closures and cancellations of activities in schools - Donations to the Red Cross - american Red Cross provided relief to people in affected areas funded through some of the media efforts - media help to raise a large amount of funds, to victims charity concert, telephones and corporate donations - Power companies attempted to prevent long-term power fails by being prepared to repair storm damage on by having employees work longer hours - fedex transporter medical supplies to affected areas for free Governmental: - National Garden US Air Force put as many as 45,000 personality at least seven states on alert for possible duty in response to the preparations and aftermath of hurricane Sandy - Use of satellite information allowed for real time analysis of where the damage was worse. Alongside this healthcare/education/income data was looked at to work out where the worst areas would be and so where the government should go first. - Flight cancellations were put in place - Federal emergency management agency provided 7000 people to establish 65 disaster recovery centres and gave over $600 million in direct assistance to individuals impacted by the storm - Residents evacuated - Federal emergency management agency monitored Sandy - emergency services rescue those were injured or endanger - metro services: rail and buses were cancelled - $50.5 billion hurricane Sandy relief bill was passed three leg legislation to help rebuild and support victims - New York set up a local government office to support the rebuild - State of New York is the local government office to coordinate relief efforts and ensure that all areas would be helped

Question 37

Responses to typhoon Haiyan

Answer 37

Governmental: - The elderly and infirm were responded to 1st by rescue them on floating beds - President declared military law in some areas-issues were exacarbated by the fact that 100 police out of 1300 reported for duty - Armed police deployed to protect fuel and aid supplies from looters - 1200 evacuation centres built to help the homeless - Field hospitals set up to help the injured and basic food distributed - International fundraising appeals were initiated $131 from the UK loan through the Philippines Typhoon appeal Organisation: - Imagine the response coordinated by organisations like the Red Cross and disaster emergency committee - Grants were made for local fisherman to buy new fishing boats-funded by Oxfam - Thermal cameras used to detect bodies buried out of the debris - Infrared satellite images were used to locate areas of devastation - Open Street map team use crowd source information to keep the global community updated - Social media assisted the relief operations by supporting organisation of volunteer support Individual: Google person finder enables people to track friends and family

Question 38

Why would the impacts difference between typhoon haiyan hurricane Sandy

Answer 38

- Power cut with typhoon, difficult to aid without light - Typhoon more deaths, less time to evacuate, stronger cyclone - Typhoon more foreign aid - typhoon more damage, buildings less damage proof - Hurricane more cost damage, more expensive things - Typhoon more people homeless, less money for aid