KS3 Weather and Climate

Weather and Climate

What is Weather?

  • Definition: Weather refers to the atmospheric conditions at a specific time and place, including short-term variations in the environment.

  • Factors to Consider: This includes temperature, humidity, wind speed, atmospheric pressure, and precipitation levels at a specific location.

What is Climate?

  • Definition: Climate is the average of weather conditions over an extended period, typically 30 years,

Main Factors Influencing Weather

  • The sun is the primary driver of weather patterns, affecting temperature and wind. Tie these discussions back to earlier knowledge on the water cycle, which is crucial for precipitation.

Weather Layers

  • Different atmospheric layers where weather occurs:

    • Exosphere: 10,000 km above ground.

    • Thermosphere: 690 km above ground.

    • Mesosphere: 85 km above ground.

    • Stratosphere: 50 km above ground.

    • Troposphere: 6-20 km above ground, where most weather events occur.

Measuring the Weather

Air Pressure

  • Measured using a barometer and recored using a barograph

  • It is measured in millibars) (mb)

  • Average air pressure is 1000 mb.

Anemoter

• Is used to measure wind speed.

• The Beaufort Scale describes the strength of

wind.

Wind Direction

  • Wind Vane is a free moving arrow on mast high

  • The tail of the ad arrow wide and blown.


    Hygrometer

•Measures humidity, tells us how much vapour is

in the air

Campbell Stokes Recorder / Sunshine recorder

•Measures the hours of sunshine each day

Temperature

Air temperatures are measured using a maximum and minimum thermometer

Precipitation

Any moisture that falls from the sky

We measure precipitation using a rain gauge


Air Masses

Polar Continental (cP): Cold and dry, originating over land in polar regions, bringing cold weather and clear skies.

Tropical Maritime (mT): Warm and humid, formed over warm oceans, leading to precipitation and warm temperatures in coastal areas.

Polar Maritime (mP): Cool and humid, formed over cold oceans, resulting in cool temperatures and overcast skies with precipitation inland.

Tropical Continental (cT): Warm and dry, originating over land in tropical regions, associated with hot, clear weather and potential heatwaves.


Air Pressure

Low air pressure means air is rising

High air pressure means air is sinking


Low Pressure/ Depression

The fall in air pressure is a sign of rain and wind, the lower the pressure the less the weather


High Pressure/Anticyclone

High pressure means clear skies with no clouds.Thats what gives us our cold winters and hot summer.


Meteorologist

  • Definition: A meteorologist is a scientist who studies the atmosphere and weather patterns, utilizing various data collection methods to predict weather and understand climate.

Understanding Precipitation

  • Definition: Precipitation encompasses any moisture falling from the atmosphere, including rain, snow, hail, and sleet.

  • Measurement Tools: Utilizes a rain gauge; placement is critical to ensure accurate readings unaffected by wind or nearby structures.

  • Types of Precipitation:

    • Rain: Liquid water droplets that fall when atmospheric conditions are warm enough to keep them from freezing.

    • Snow: Frozen crystalline water that falls when temperatures are below freezing.

    • Hail: Ice pellets that form in strong thunderstorms with intense updrafts.

    • Sleet: Small ice pellets that occur when raindrops freeze before hitting the ground.

Global Climate Types

Various climate types that exist around the world include but are not limited to:

  • Tropical: Warm and wet, typically near the equator.

  • Temperate: Moderate temperatures, with distinct seasons.

  • Continental: Characterized by extreme temperatures, with hot summers and cold winters.

  • Polar: Cold, with minimal precipitation, typically found near the poles.

  • Hot Arid: Hot and dry conditions, limited vegetation.

  • Cold Arid: Cold and dry, often with tundra conditions.


4 types of clouds

  1. Cumulus Clouds: Fluffy, white clouds with a flat base, often associated with fair weather.

  2. Stratus Clouds: Thick, gray clouds that cover the sky like a blanket, often bringing drizzle or light rain.

  3. Cirrus Clouds: High, thin, wispy clouds typically indicating fair weather but may suggest a change in the weather.

  4. Nimbostratus Clouds: Thick, dark clouds that cover the sky and produce steady, continuous rain


The three types of rainfall are:

  1. Frontal Rainfall: Occurs when a warm, moist air mass meets a cool, dense air mass, leading to precipitation after the warm air cools and condenses. Common in temperate regions.

  1. Conventional Rainfall: Results from surface heating; warm, moist air rises, cools, and condenses to form clouds and precipitation. Most common in tropical areas.

  2. Relief Rainfall: Occurs when moist air rises over mountains, cools, and creates precipitation on the windward side, while the leeward side has less precipitation, resulting in a rain shadow.