Year 8 Geography: Weather

Weather is the Day to Day atmosphere of a Certain place While Climate is the opposite, it is instead the Long term atmosphere.

There are 6 elements of weather with 6 pieces of equipment that we use to measure them.

Elements of Weather

  • Temperature: measured with a Thermometer (degrees Celsius)

  • Rainfall rain: measured with Rain gauge (mm)

  • Air Pressure: measured with a Barometer (milibars)

  • Wind speed: measured with an Anemometer (mph)

  • Wind Direction: measured with a weather vane (compass points)

  • Cloud Cover: measured with your eyes (Oktas)

This is how we plot down weather Data:

Each feature represents something about the current weather for example: the 12 at the top of this image indicates the temperature.

Symbol meanings:

The water Cycle

Evaporation: the process of Water turning into a gas (water vapour )

Condensation: the process of Water Vapour turning to a liquid

Precipitation: water falling from the sky, it could be a solid, liquid or gas form

Surface Runoff: The process of Water being moved by gravity towards larger water accumulations

Groundwater: Water stored in the ground/flowing in the ground

Transpiration: The process of a plant absorbing water and releasing water vapour through it’s leaves.

Cold air cannot hold water vapour

Hot air Can hold water vapour

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How do clouds form?

  1. Firstly, the sun heats up the ground. This causes the air at ground level to rise and the air vapour within to cool down (since the further away from the ground the colder it gets)

  2. When cooled, The water vapour collides and sticks to particles found in the air known as condensation Nuclei that contain aerosols such as salt and dust.

  3. As the Water Vapour rises and cools, more Water Vapour accumulates and condenses on the surface of the Nuclei.

  4. When enough water vapour condenses around the Nuclei a cloud droplet is formed.

  5. Individual cloud droplets are lightweight, tiny and spread out so they stay afloat as the form of a cloud.

  6. At times, the cloud droplets combine to become larger droplets or crystals. As this occurs, they grow in size and weight and gradually fall from the sky as rain.

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୨⎯𝕽𝖆𝖎𝖓𝖋𝖆𝖑𝖑⎯୧

There are 3 types of Rainfall in total

Relief Rainfall

  1. Sun heats up land and Water evaporates from a body of water in close proximity of a mountain.

  2. The water Vapour rises and begins to ascend the mountain, cooling the gas in the process.

  3. The water condenses and falls on the singular side of the mountain.

  4. On the other side, air descends warms and becomes drier. That is why the opposite side of the mountain is commonly drier, this is what we call the rain shadow.

Frontal Rainfall

    • Warm air rises

    • Air cools and condenses

    • Cloud formation

    • Precipitation occurs

    • Rain falls

Convectional rainfall

  1. Sun heats up land then Water evaporates and rises as water vapour.

  2. Water Vapour cools as it rises further upwards.

  3. Cloud process/ Water vapour condenses

  4. Rain falls

There are 10 types of clouds

Stratus

Flat or smooth

Cumulus/cumulo

heaped up/puffy, like cauliflower

Cirrus/cirro 

high up/wispy

Alto

medium level

Nimbus/Nimbo

rain-bearing cloud

୨⎯How Climate Varies⎯୧

Biomes are global scale ecosystems like desert and polar.

They are completely dependent on the different climates in each location

But what exactly makes the Climates so different from each other?

Well here are 5 factors that affect the Climate of a Biome.

  1. Altitude

    Contrary to popular belief, Getting closer to the sun will not make you any warmer. This is because the sun does not hit us directly but instead comes into contact with the ground and heats it up instead. From there, the ground warms up the air which supplies

    us with warmth in the process.

The higher up we go, the further we are from the ground supplying us with warm and therefore it gets colder. This is also why we see snow at the top of mountains.

  1. Rain shadow

Many deserts are found on the leeward sides of mountains while precipitation falls on the other side.

  1. Distance to the Sea

    In winter, the seas are warmer than the land and therefore warms up places closest to the sea. In summer, the sea is cooler so it instead decreases the temperature of the land.

  2. Ocean Currents

The world's oceans move constantly in patterns that are called currents. 

This can spread heat from the equator to places further north and south

  1. Gulf stream

    Warm water from the equator travels north from the Gulf of Mexico into the Atlantic Ocean. This part of the Gulf Stream is called the North Atlantic Drift.

୨⎯UK Extreme Weather⎯୧

Extreme weather is any weather event which is significantly different from the average or usual weather for a place at that time.

What reasons could the U.K experience Extreme Weather?

Reason 1: UK Roundabout

An air mass is a large body of air that travels from one place to another.

We use a combination of different words to describe these air masses

Maritime:

Wet Weather

Polar:

Cold Weather

Continental:

Dry Weather

Tropical:

Warm weather

Reason 2: Jet streams

A jet stream is a strong air current.

We are affected by the polar jet.

When the polar jet stream moves north over the UK, we get hot weather. When it moves south over the UK, we get cold weather. 

୨⎯What are Hurricanes?⎯୧

A tropical storm is a huge storm that develops in the Tropics.

Low pressure:

Areas where warm air rises upwards.

The Saffir-Simpson scale rates hurricanes on a scale of 1-5 according to their wind speed with 5 being the strongest.

Due to Storm Surges, being in close proximity to the coastline during a hurricane is incredibly dangerous and could end in copious amounts of death as well as this, hurricanes lead to large expenses and destruction of property due to flooding

Storm surge is the abnormal rise in seawater level during a storm, you see as pressure falls, water rises and as the hurricanes move, the strong winds push the water towards the land.

The three main hazards are…

  1. Winds

  2. Storm surges

  3. Tornadoes

Case study: Hurricane Katrina

Hurricane Katrina was a major tropical storm which hit the city of New Orleans (among other places) in August 2005.

List of Impacts:

  • 1800 deaths

  • 300,000 homes destroyed

  • Shops were looted

  • Fuel prices rose

  • Tourism decreased, meaning loss of income for businesses.

  • 3 million people with no electricity

  • Cotton and sugar crops destroyed

  • Damage to coastal habitats

  • 80% of New Orleans was flooded

  • $300 billion of damage ($81 in New Orleans)

  • Coastal habitats were flooded

Structure of Tropical Storms;

Monsoons

What causes the Monsoon?

Worded explanation:

The monsoon is the wet season from june to october. It is caused when the winds change direction and blow moist air from the ocean over the continent. The himalayas are a physical barrier to these winds, forcing the air to rise and create relief rainfall. The winds change direction as the Land becomes warmer than the sea. In october, winds change direction again and the weather changes back to the dry season. In this process the land heats up quicker.

Moonsoon comes from the arabic word mausim meaning seasons and the term is normally associated with heavy rain

60% of the world’s population lives in areas affected by monsoons.

Accounts for 80% of the rainfall in India

70% of the indian population rely on the rain for agriculture

La Nina ensures wetter monsoons

Before a monsoon air pressure is high……..

Negatives of a Monsoon:


Marked Questions:

6 mark

Point

Evidence

Explain

x2

Conclusion: “I believe _____ is stronger“