3.1 The weather

• Aardrijkskunde
• Middelbare school
• havo, vwo
• Leerjaar 3

3.1 The weather

Learning objectives

• Define the keyword ‘weather’
  
• Explain the four most important parameters when it comes to the weather.

Weather

Weather is the current state of the atmosphere.

Lowest layer of the atmosphere = the troposphere.

Four main characteristics of weather:

1. Temperature.
2. Precipitation.
3. Wind.
4. Cloud cover. 

What kind of weather do you prefer?

The weather in Maastricht on

January 5th 2016.

The weather in Groningen on

January 5th 2016.

Temperature

meteorologists often use an isotherm map

Isotherm = a line in a map that shows equal temperature.

Degrees or Fahrenheit

Most countries have agreed to use degrees Celsius to measure temperature. Many former British colonies such as Canada, India, Australia and the UK itself have switched from Fahrenheit to Celsius. However, the United States and four other countries still use the Fahrenheit scale. To calculate the temperature in Fahrenheit, you have to multiply the temperature in °C by 1.8 and add 32.

What do we call the process in which water vapour turns into liquid water?

1. Evaporation
2. Precipitation
3. Condensation
4. Transpiration

Wind

The Beaufort scale indicates the strength of the wind. 

Wind is the movement of air through the atmosphere. 

It is caused by atmospheric pressure = pressure of the air in the atmosphere.

Air going down = high pressure (H)

Air rising up = low pressure (L)

Law of Buys Ballot = The flow of the wind is always from high pressure areas to low pressure areas. Furthermore, this wind is deflected towards the right in the Northern Hemisphere and to the left in the Southern Hemisphere. 

Isobars over the UK: H means high pressure zone, L means low pressure zone. What is the current wind direction over Scotland?

What's the difference between 'weather' and 'climate'?

Essence

Weather is the current state of the atmosphere. This means it easily changes and it can be different when you move from one place to another; but it can also change when you simply sit in the same spot for a while. The four most important variables we look at when we measure the weather are temperature, precipitation, wind and cloud cover.

3HT: Do 3.1, ex. 3, 4, 5a, 6 to 9 and 12

Thursday 24 March, 2nd hour:

• Study 3.1
• Do 3.1, ex. 3, 4, 5a, 6 to 9 and 12 

Clouds

Different types of clouds:

• High clouds, such as cirrus clouds, look like feathers; if they thicken, you can be sure that rain is coming. 
• Low clouds, such as stratocumulus clouds do not always bring rain, only if the cloud layer is sufficiently thick. 
• Cumulonimbus clouds are vertical clouds: they go high enough to reach the boundary of the troposphere, which forces them to spread out. Cumulonimbus clouds bring thunderstorms.

What type of cloud do you see here?

1. Cirrus clouds
2. Stratocumulus clouds
3. Cumulonimbus clouds
4. Altocumulus clouds

www.bbc.co.uk

3VT: Do 3.1, ex. 3, 4, 5a, 6 to 9 and 12

Thursday 24 March, 2nd hour:

• Study 3.1
• Do 3.1, ex. 3, 4, 5a, 6 to 9 and 12