Weather hazards and climate change Flashcards

1
Q

What is the atmosphere?

A

The atmosphere is the layer of air surrounding the Earth’s surface which extends hundreds of kilometres high

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2
Q

What is weather and what is climate?

A

Weather is the short term day to day conditions of the atmosphere
while Climate is the long term average temperature and rainfall.

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3
Q

Which part of the atmosphere does weather take place in?

A

Troposphere

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4
Q

What and where is the Hadley cell and what are its effects?

A

The first cell is called the Hadley cell. 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. As the air rises, it cools and forms thick cumulonimbus (storm) clouds. The air continues to rise up to the upper atmosphere, and the following then happens:

The air separates and starts to move both north and south towards the poles.
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. This creates an area of little cloud and low rainfall, where deserts are found.
The Hadley cell is then complete. The air completes the cycle and flows back towards the equator as the trade winds.
In the northern hemisphere, the winds flow to the right and are called northeast trade winds. In the southern hemisphere the winds flow to the left and are called the southeast trade winds. This is down to the Coriolis effect and friction.

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5
Q

What is the Coriolis effect and its impacts on the weather of the uk?

A

Apparent force, due to the spinning of the Earth, which deflects movement of particles and wind.

In the UK, which winds are blown from the south due to the Ferrell cell but the earth spins to the right causing the prevailing wind to hit the UK in a south-westerly direction.

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6
Q

What and where is the Ferrell cell?

A

The Ferrel cell occurs at higher latitudes (between 30 degrees and 60 degrees N and 30 degrees and 60 degrees S):

Air on the surface is pulled towards the poles, forming the warm south-westerly winds in the northern hemisphere and north-westerly winds in the southern hemisphere.
These winds pick up moisture as they travel over the oceans. At around 60 degrees N and 60 degrees S, they meet cold air, which has drifted from the poles.
The warmer air from the tropics is lighter than the dense, cold polar air and so it rises as the two air masses meet.
This uplift of air causes low pressure at the surface and the unstable weather conditions that are associated with the mid-latitude depressions. Much of our wet and windy weather in the UK is determined by this.

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7
Q

What is the polar cell and its effects?

A

At the poles, air is cooled and sinks towards the ground forming high pressure, this known as the Polar high. It then flows towards the lower latitudes. At about 60 degrees N and S, the cold polar air mixes with warmer tropical air and rises upwards, creating a zone of low pressure called the subpolar low. The boundary between the warm and cold air is called the polar front. It accounts for a great deal of the unstable weather experienced in these latitudes.

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8
Q

What are ocean currents?

A

Heat from the tropics can be transferred to the cold polar regions, by large-scale water movement within the oceans. Each ocean has its own circular pattern of currents. Heat is transferred by warm ocean currents, such as the North Atlantic Drift in the Atlantic Ocean, from low latitudes to high latitudes. Ocean currents are set in motion by the prevailing surface winds associated with the general atmospheric circulation. The direction of water movement is also deflected by the
Coriolis effect.

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9
Q

What is pressure and the difference between high and low pressure?

A

Pressure is measured in millibars. Standard pressure at sea level is 1013 millibars, but large areas of either high or low pressure can occur. Areas of high and low pressure are caused by rising and sinking air. As air warms, it rises, leading to low pressure at the surface. As air cools, it sinks leading to high pressure at the surface.Low pressure causes wet conditions and High pressure causes dry and clearer conditions.

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10
Q

What is relief rainfall and why is the west of the UK so wet?

A

Relief rainfall, also known as orographic rainfall, occurs in areas where land increases height. It is widespread on the west coast of the United Kingdom due to the prevailing weather coming from that direction.

Relief rainfall is formed when the air cools as it rises over relief features in the landscape such as hills or mountains. As the air rises, it cools, condenses and forms rain.

In the UK, prevailing winds from the west lead to air rising over upland areas like the Pennines. As a result, rainfall totals of over 1,600 mm per year occur in the west of the UK. The downwind or leeward slope receives a small amount of rainfall in comparison.

Stage 1.
Warm wet air is forced to rise over high land.

Stage 2.
As the air rises, it cools and condenses. Clouds form, and precipitation occurs.

Stage 3.
The drier air descends.

Stage 4.

As the air descends, it warms, meaning it can carry water moisture, so there is little rain on this side of the mountain. This area is known as a rain shadow.

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11
Q

What is the climate of the UK?

A

The UK has a temperate climate. In general, this means that Britain gets cool, wet winters and warm, wet summers. It rarely features the extremes of heat or cold, drought or wind that are common in other climates. The weather conditions are also very changeable.

Not all parts of the UK have the same climate. London, in the south-east of the UK, is a region characterised by a warm and dry climate in the summer and a cold and dry climate in the winter.

Cumbria, in the mountainous north-west of England, has generally cooler temperatures and more rainfall throughout the year.

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12
Q

What is a glacial and an interglacial?

A

A glacial is a period of cold while an interglacial is a period of warm?

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13
Q

What are the patterns of climate across the UK

A

The general pattern of the climate across the UK has four distinct regions:

south-east – cold winters, warm and dry summers
south-west – mild and very wet winters, warm and wet summers
north-west – mild winter, cool summers and heavy rain all year
north-east – cold winter, cool summers and steady rain all year

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14
Q

What is precipitation?

A

Precipitation is any form of moisture which falls to the earth. This includes rain, snow, hail and sleet.

Precipitation occurs when water vapour cools. When the air reaches saturation point (also known as condensation point and dew point) the water vapour condenses and forms tiny droplets of water. These tiny droplets of water from clouds.

Complex forces cause the water droplets to fall as rainfall.

All rain is the same. It happens as the result of warm, moist air being cooled, leading to condensation and in turn rain. The following examples show three different ways air is cooled causing rainfall.

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15
Q

What was the last major cold period?

A

The last major cold period was known as the Pleistocene. It started 2.6 million years ago and ended just 10,000 years ago. Since then, conditions have been warmer. This current warm phase is known as the Holocene. The Holocene and Pleistocene are part of the Quaternary Period of Earth’s history.

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16
Q

What are the different methods of collecting evidence of climate change?

A

Ice Cores:
Scientists often use
ice cores to detect changes in temperatures. When snow falls it traps air into the ice. When scientists take a core of ice it reveals the atmospheric gas concentrations at the time the snow fell. This is used to calculate temperature at that time. The ice can reveal the temperature of each year for the past 400,000 years. Scientists that study the ice cores say there is clear evidence that there has been a rapid increase in temperature in the past decades.

Thermometer readings:
Ongoing temperature recordings using thermometers have shown a clear warming of the Earth’s temperature over the past few decades. By using this data, scientists have found that the Earth’s average surface air temperature has increased by around 1°C since the year 1900. The period between 2013 and 2022 was the warmest 10-year period on record; 2016 and 2022 are the warmest years since records began. The degree to which the climate warms in the future will depend on natural climate variability and the level of greenhouse gas emissions. If greenhouse gas emissions continue then average global temperatures will rise. However, some regions such as the Arctic will warm faster than others.

Pollen:
By analyzing pollen from well-dated sediment cores, paleo climatologists can obtain records of changes in vegetation going back hundreds of thousands, and even millions of years. Not only can pollen records tell us about the past climate, but they can also tell us how we are impacting
our climate.

Tree rings:
Because trees are sensitive to local climate conditions, such as rain and temperature, they give scientists some information about that area’s local climate in the past. For example, tree rings usually grow wider in warm, wet years and they are thinner in years when it is cold and dry.

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17
Q

What is the greenhouse effect?

A

A natural function of the Earth’s atmosphere is to keep in some of the heat that is lost from the Earth. This is known as the
greenhouse effect
.

The atmosphere allows the heat from the Sun (short-wave radiation) to pass through to heat the Earth’s surface.
The Earth’s surface then gives off heat (long-wave radiation).
This heat is trapped by
greenhouse gases
(eg methane, carbon dioxide and nitrous oxide), which radiate the heat back towards Earth.
This process heats up the Earth.

18
Q

What human factors increase global warming?

A

Burning fossil fuels, eg coal, gas and oil - these release carbon dioxide into the atmosphere.
Deforestation - trees absorb carbon dioxide during photosynthesis. If they are cut down, there will be higher amounts of carbon dioxide in the atmosphere.
Dumping waste in landfill - when the waste decomposes it produces methane.
Agriculture - agricultural practices lead to the release of nitrogen oxides into the atmosphere.

19
Q

What are the natural factors increasing global warming?

A

There are also natural factors which contribute to increased global warming:

Orbital changes - the Earth has natural warming and cooling periods caused by
Milankovitch cycles
or variations in the tilt and/or orbit of the Earth around the Sun (Wobble, roll and stretch theory).
Volcanic activity - during a volcanic eruption carbon dioxide is released into the atmosphere.
Solar output - there can be fluctuations in the amount of radiation from the sun. If there is high amount emitted there will be an increase in Earth’s temperatures.

20
Q

What are the impacts of climate change in the UK and in the World?

A

Impacts of climate change in the UK:
sea levels could rise, covering low lying areas, in particular east England
droughts and floods become more likely as extreme weather increases
increased demand for water in hotter summers puts pressure on water supplies
industry may be impacted, eg Scottish ski resorts may have to close due to lack of snow

Impacts of climate change around the world:
sea level rise will affect 80 million people
tropical storms will increase in magnitude (strength)
species in affected areas (eg Arctic) may become extinct
diseases such as malaria increase, an additional 280 million people may be affected

21
Q

What are the three orbital changes?(Milankovitch cycles)

A

Eccentricity:
The orbit of the Earth around the Sun changes from a near-perfect circle to an ellipse (squashed circle/oval). This affects how intense the Sun’s rays are on Earth. If the Earth is orbiting in an elliptical shape, it will be further away from the Sun at certain points than if it was orbiting in a circle. 1 cycle takes around 100,000 years.
Obliquity:
The tilt of the Earth’s axis, which changes from 21.5° and 24.5° (currently 23.5°). Affects the contrast between summer and winter seasons. To change between 21.5° and 24.5° takes around 41,000 years.
Precession:
Describes the wobble of the Earth’s axis (imagine the movement of a spinning top when it starts to slow down - the Earth wobbles on its axis in a similar way). Affects the length of days, especially in the poles. A full cycle takes just over 20,000 years.

22
Q

What is a tropical cyclone?

A

A tropical cyclone is a very powerful low-pressure weather system which results in strong winds (over 120 km/h) and heavy rainfall (up to 250 mm in one day). Tropical cyclones have different names depending on where they occur in the world. In the US and the Caribbean they are known as hurricanes, in South Asia - cyclones, in East Asia - typhoons and in Australia they are known as willy-willies. They all develop in the same way and have the same characteristics.

23
Q

Describe a tropical cyclone

A

In appearance, a tropical cyclone is like a huge whirlpool - a gigantic mass of revolving moist air.

Tropical cyclones (or storms) are between 482-644 kilometres wide and 6-8 km high. They move forward at speeds of 16-24 km/h, but can travel as fast as 65 km/h. The
Coriolis force
caused by the rotation of the Earth causes the tropical cyclone to spin.

The central part of the tropical cyclone is known as the eye. The eye is usually 32-48 km across. It is an area of light wind speeds and no rain. It contains descending air.

Large towering
cumulonimbus
clouds surround the eye. These are caused by warm moist air
condensing
as it rises. This leads to very heavy rainfall and wind speeds of up to 320 km/h.

24
Q

How do tropical cyclones develop?

A

Cyclones form between approximately 5° and 30° latitude. Because of easterly winds they initially move westward.
They occur most commonly in early autumn as this is when sea temperatures are at their highest, temperatures having built up over the summer.
The air above the warm ocean is heated. Once the ocean water reaches at least 27°C, the warm air rises quickly, causing an area of very low pressure.
As the air continues to rise quickly it draws more warm moist air up from above the ocean leading to strong winds.
The rapidly rising warm air spirals upwards, cools, condenses and large cumulonimbus clouds form.
These clouds form the eye wall of the cyclone and produce heavy rainfall.
In the centre of the cyclone, cold air sinks forming the eye of the cyclone - here, conditions are calm and dry.
When tropical cyclones reach a land surface, they begin to lose their energy and die out. This is because they are no longer receiving heat energy and moisture from the ocean, which is needed to drive them.

25
Q

What are hazards associated with tropical cyclones?

A

When a tropical cyclone arrives at a coastline, it is potentially fatal and can cause damage to property. This is because tropical cyclones bring with them:

Storm surges – these are huge surges of high water up to 3 metres in height that sweep inland from the sea, flooding low-lying areas.
Strong winds – winds of over 120 km/h (75 mph) blow inland, which are capable of causing significant damage and disruption, for example by tearing off roofs, breaking windows and damaging communication and transport networks.
Torrential rain and flooding – the warm, humid air associated with a tropical cyclone produces very large amounts of rainfall, often in excess of 200 mm in just a few hours. This can cause short-term
flash flooding, as well as slower river flooding as the cyclone moves inland.

26
Q

How are tropical cyclones predicted?

A

There are several specialist tropical cyclone forecasting centres around the world such as the National Hurricane Centre in Miami, Florida.

The centre uses satellite images, various weather instruments and computer-based prediction modelling to detect and track tropical cyclones. When tropical cyclones affecting populated coastal areas are predicted, the centre issues warnings.

Warnings give information to the local authorities of places likely to be in the tropical cyclones’s path. This means that preparations can be made to try to protect public safety. These are broadcast over TV and radio and warnings can be issued to smart phones. People in vulnerable coastal areas are usually advised to secure their property and move away. In the USA, this can involve the mass evacuation of a million or more people.

Reinforced aircraft, fitted with various scientific instruments, fly through and over tropical cyclones to collect data. This can be used to help track and predict the path of a tropical cyclone.

27
Q

What are the social economic and environmental impacts of hurricane sandy?

A

Social-More than 150 people were killed by the hurricane. Businesses and homes damaged. Transport disrupted. No electricity for days.
Economic- Total property damage estimated at 65billion USD and the New York stock exchange closed disrupting the global economy.
Environmental-Nature reserves such as prime hook national wildlife refuge were destroyed and flooding led to millions of gallons of sewage pollution.

28
Q

Responses to Hurricane Sandy?

A

Organisations: Media played a large part raising funds
Charity concerts were organised along with telethons and corporate donations to help relief. Charities such as American red cross provided relief to those affected
Government-The state of New York set up an office to to co-ordinate rebuilding efforts. Some of this money was given to homeowners and businesses directly
Meteorologists predicted where the cyclone was going to go to help areas and prevent the damages and evacuate people.
Individuals- showed social media different views of the cyclone helping meteorologists predict where the storm would land.

29
Q

Impacts of Typhoon Haiyan

A

Social-more than 6k dead, Power disconnected to regions and infrastructure blocked exits and entrances.
Thousands homeless and lack of order. Mass Panic
Economic-USD 2 billion in damages and infrastructure damaged making aid difficult.
Environmental-mangroves damaged, Chemical spills from damaged industrial facilities and an Oil tanker Overturned leaking oil. Sea water contaminated drinking water supplies.

30
Q

Responses to Typhoon Haiyan.

A

Govt-Seven provinces placed under a state of national calamity which allowed the government to redirect funds to address problems created by the cyclone. Police and Army tried to retain order within the panicked people. The Uk sent a package to help with relief efforts.
Organisations- Charities helped raise funds for the typhoon

31
Q

What are droughts? Why are deserts not considered in drought?

A

when there is abnormally low rainfall for an extended period of time. Droughts can last from weeks to months and even years. A desert would not be considered in drought unless it had less rainfall than normal, for a long period of time.

32
Q

What are the three types of drought?

A

Meteorological drought – when the amount of precipitation received in a specific area is less than the average.
Hydrological drought – when reduced precipitation impacts on water supply, e.g there is decreased streamflow, soil moisture, reservoir and lake levels, and groundwater.
Agricultural drought – when the above two types of drought impact on agricultural activities, e.g reduced soil moisture or reservoir levels required for
irrigation.

33
Q

What human activities increase the risk of drought?

A

Agriculture – using large amounts of water to irrigate crops removes water from lakes, rivers and groundwater. Some crops require more water than others, eg cotton.
Dam building – large dams can be built across a river to produce electricity and store water in a reservoir. This can reduce river water flowing downstream and cause drought below the dam.
Deforestation – removing trees can reduce the amount of water stored in the soil as rain tends to fall and wash off the land as surface run-off. This leaves the ground vulnerable to erosion and desertification which can lead to drought.

34
Q

What other factor affects whether a country can get drought?

A

How it receives precipitation (e.g Rainy season)

35
Q

How do droughts form?

A

In regions of high pressure, dry air stops clouds from forming and stops raining.

36
Q

What are the hazardous impacts of drought?

A

Approximately 780 million people worldwide lack a reliable and sufficient water supply. This can have many serious impacts:

A lack of clean and reliable water can cause people in developing countries to drink contaminated water which could cause a range of diseases such as cholera and typhoid.
Commercial and
subsistence farmers
can experience high crop or livestock losses and a reduction in the land’s value. Subsistence farmers may experience
famine.
With less moisture and rainfall, wildfires can become common, damaging crops, buildings and even causing death.
Businesses and services which rely on clean water may be closed, eg hospitals and restaurants.
Conflicts or war between people and countries can occur when pressure is put on water supplies. It can also lead to people having to migrate away from drought-stricken areas.

37
Q

What is subsidence?

A

Subsidence is when the ground beneath a building sinks, pulling the property’s foundations down with it. Subsistence usually occurs when the ground loses moisture and shrinks.

38
Q

What are the impacts and responses of drought in a developed country (California)?

A

-Subsidence
-Sea water intrusion
-Lack of water
-Wildfires
-Effect on Agriculture(1.8b USD lost and 10k jobs lost)
-power supplies affected

-Individuals: Farmers conserve irrigation water and use safe irrigation techniques
-Govt: Measures include; limiting flows during winter months to build up reserves for later.
Warning some areas on water limits as river levels may be low.
-reducing water supplies to minimum only for public health and safety
-salinity control points to stop seawater intrusion
-running education programs
-Monitoring rivers.

39
Q

Effects on drought in a developing country (Ethiopia)

A

85% depend on farming
Unreliable rains making planting crops and raising livestock very difficult in agriculture
Reduce food supplies leads to higher costs
Hunger, Malnutrition
Only 57% of Ethiopians have access to safe water so water quality is an issue.

40
Q

Responses to Ethiopia’s drought:

A

Organisations: Charities such as UNICEF and Oxfam work with Ethiopian experts to support worst affected and provide clean drinking water food and care. Also helps them become more drought resilient.
Live Aid is a charity organisation in the 80’s that brought global attention to Ethiopia’s Plight and raised funds for relief.
Govt-The Ethiopian govt has developed rapidly and now organises its own relief programs. They are now implementing sustainable farming techniques.

41
Q

Impacts of drought:

A

Social:-Ill health by lack of clean drinking water
-Depression over economic impacts
-Risks over wildfire and dust storm damages
-Migration
Economic:
-Industries such as farming and forestry are unable to support jobs leading to mass unemployment
-Water companies spend a lot of money
-Food prices increase as farming becomes expensive and difficult.
-Related Industries would see a drop in income
Environmental:
-wild animals suffer from lack of water
-freshwater habitats become damaged or lost
-Soil becomes dry and cracked , can no longer support plants
-Wildlife endangerment or migration