Unit 2: The atmosphere                                                     1   2   3   4   5

3. Weather and climate

3.1. Weather

Weather describes the state of atmospheric conditions at a certain place,

over a short period of time.

Weather conditions are variable and include:

- Humidity. This is the concentration of water vapour in the atmosphere.

- Clouds. They form when rising air cools.

- Precipitation. This is water that falls to the ground: rain, snow and hail.

- Temperature. This represents how hot or cold the air is.

- Wind. This is air in motion.

Meteorology is the study of different atmospheric variables to make weather predictions. Meteorologists collect information about weather conditions (temperature, precipitations, etc)

The most important meteorological instruments are:

3.2. Climate

Climate describes the characteristic pattern of weather in an area, over a long period of time. The climate of a region is expressed in terms of temperature

and precipitations. 

The unequal warming of the planet provokes the formation of large air masses

with different degrees of humidity and temperature. These masses can be cold or warm, and dry or humid.

These air masses move around and have interaction. The place where cold air meets warm air is called a front.

       - A warm front occurs when a mass of warm air moves

         towards a mass of cold air.

       - A cold front occurs when a mass of cold air moves

         towards a mass of warm air.

Factors affecting climate are:

- Latitude

  It indicates how far north or south a place is from the Equator.

  The temperature increases from Poles to Equator.

- Altitude

  This is the height above sea level. The higher a place is, the colder it will be.

- Distance from the sea

  Water heats up and cools down slower than land.

  The sea keeps coastal areas warmer in winter and cooler in summer.

- Ocean currents

  They can be warm when they come from tropics or cold, when they

  come from poles. They make the climate softer.

3.1. What is the difference between weather and climate?

3.2. The picture represents a meteorological station. Indicate what

        instrument each letter represents and explain what atmospheric

variable it measures. Then, listen and indicate which description corresponds to each instrument.

3.3. What factors affect the climate of a region?

3.4. Look at the weather map and answer the questions into your notebook:

a. Over which country is the depression?

b. Where do you situate an anticyclone?

c. Which country is the cold front moving towards? And the warm front?

d. Will there be clear skies in Spain? Or will it rain?

e. Where is the wind stronger, in the Iberian Peninsula or in Italy?