Activities 1. What is the weather like in the British Isles? Unit 3 Weather and Climate In pairs, ask questions and answer about each city shown in the map. What is the weather like in Manchester? It’s partly cloudy. Weather and Climate • Aberdeen 2. Write a definition for each of the following: What is weather? • Glasgow 1. season – The weather describes the condition of the atmosphere in a given location sunny partly cloudy • Belfast over a short period of time, for example, from day to day or week to week. The • Manchester weather includes daily changes in precipitation, humidity, air temperature, 2. climate – . air pressure and wind conditions. The atmosphere is constantly changing: cloudy raining in a very short time, it can be hot or cold, wet or dry, calm or stormy, clear 3. meteorologist – • London • Cardiff or cloudy. Meteorologists are scientists who record the weather every day. Weather stations collect data and computers process it. Then this data is analysed by 3. Mark Twain said: “Climate is what you expect, weather is what you get.” meteorologists, who make predictions or forecasts about the weather. snowing stormy Explain the meaning of this sentence in your own words. How does the weather change throughout the year? Weather changes during the year in cycles. These cycles are called seasons. There are four seasons: summer, autumn, winter and spring. In Spain, summer is hot and dry with isolated thunderstorms. Autumn is cool, and often wet and windy. Winter is cold and often dry. Spring is a warm, wet season. W orking W ith the W eb What is climate? The constant recording of weather information helps to determine the climate of an area. Climate is Go to the web and find weather forecasts for the major cities in the table below. Then complete the condition of the atmosphere over a long period of time. This includes average weather conditions the table. based on data recorded over 40 years. Climate tells us what the weather is usually like in a certain place. So, for example, we say that the climate in Spain is moderate and Mediterranean. What will the Cities weather be like Highest Lowest Humidity What factors influence weather and climate? tomorrow? temperature temperature Weather and climate are influenced by the following main factors: Paris, France Latitude: The angular distance Altitude above sea level: Distance from the sea: Areas London, UK of any point on Earth, north or Climatic conditions become closer to the sea have a milder south of the equator, influences colder as altitude increases. climate. This means that the Madrid, Spain weather and climate. The sun The higher the place, the colder temperature does not vary shines directly onto Earth at the it is (0.6ºC for every 100 m of very much. Coastal areas have Cairo, Egypt equator. The North and South altitude). Higher areas tend an oceanic climate, whereas Poles receive less light from the to receive more rainfall, too. inland areas have a continental Moscow, Russia sun. Therefore, the further away Air masses have to rise over climate with a large range of you go from the equator, the mountains – as they rise they temperatures. In the summer, it New Delhi, India colder it gets. get colder and water condenses, can be very hot and dry in the forming precipitation. centre of continents. However, Beijing, China coastal areas receive more North Pole precipitation because air masses there contain more water than Website suggestions at www.burlingtonbooks.es/social1 air coming over land. At the equator, the sun shines directly onto Earth. Unit 3 SUN Equator At the Poles, the sun’s rays shine over a wider area. 18 South Pole 19 Elements of Weather and Climate Activities What are the different weather elements? 1. Complete the following fact files about six of the weather elements. Temperature: How hot or cold the atmosphere is. Temperature is measured by using a 1 2 3 precipitation Element: Element: thermometer. Temperature is usually measured Element: in degrees Celsius (°C). Degrees Fahrenheit (°F) Instrument: rain gauge Instrument: Instrument: are used by meteorologists in the USA. Unit: millimetres Unit: Unit: Precipitation: Water falling from the atmosphere. This includes 4 5 6 rain, snow and hail. Rain results Element: Element: Element: when water in the atmosphere Instrument: Instrument: Instrument: cools until it reaches saturation, Humidity: The amount of water vapour in the air. and water vapour condenses to We can measure humidity as relative humidity, Unit: Unit: Unit: form the tiny droplets of water which is expressed as a percentage. A relative that form clouds. When the humidity of 100% means that the water vapour raindrops are heavy enough, they of the air is the maximum possible. With low 2. Tick (3) the sentences T (true) or F (false). humidity, evaporation is quicker. Our sweat fall as rain. Snow is formed in a Then correct the false sentences. T F similar way, except that water rain gauge evaporates quickly on our skin and wet things vapour freezes into crystals of dry easily. When relative humidity is high, we 1. Air pressure is also called atmospheric pressure. ice as it falls. feel sticky and hot because our body sweat Precipitation is measured using a rain gauge. cannot evaporate easily. Hygrometers are the 2. Water vapour condenses to form clouds. instruments used for measuring humidity. Most rain gauges measure the precipitation in millimetres. 3. Low pressure areas form when the air mass gets warmer. Visibility: How far we can see. The sky can be Air pressure: The weight of the air in the clear, misty or foggy. Visibility is measured at atmosphere. A low pressure area, or depression, weather stations with reference to a number of 4. Snow and rain have a similar origin. is formed when warm air rises. A high pressure known landmarks at different places. area, or anticyclone, is formed when cool air 5. When relative humidity is high, wet clothes dry quickly. barometer falls. Anticyclones bring dry Wind: The horizontal movement of air from weather and depressions cause areas of high pressure to areas of low pressure. Vacuum wet weather. Air pressure is There are hot winds that blow from tropical also called barometric pressure areas, while winds blowing from polar areas because it is measured with a bring cold weather. Winds that cross oceans cause W orking W ith the W eb Mercury barometer and is expressed in precipitation, while winds blowing over land millibars. The widely used are dry. Go to the web to learn about clouds. Then answer the questions below. Air mercury barometer works Wind speed is measured using an anemometer, Pressure 1. What are clouds? by balancing the weight an instrument with three or four small of mercury in a glass tube hemispheres placed so that they catch the wind 2. Why are clouds white? against the weight of air in and revolve about a vertical rod. The revolutions 3. How do clouds move? the atmosphere. of the cups are recorded to calculate the wind velocity in km/h. Wind direction is measured 4. What is fog? Cloud cover: The portion by a wind vane, a pivoting arrow that points in 5. Clouds are categorised into three main groups. of sky covered by clouds, the direction the wind is blowing from. What are these groups called? measured in units called oktas. Each okta represents an eighth of the sky covered. So, 0 Website suggestions at www.burlingtonbooks.es/social1 okta is clear and 8 oktas is overcast. We use a cloud mirror with a grid divided into 16 equal squares to measure cloud cover. Unit 3 Sunshine: The amount of sunlight detected at a given point. A Campbell Stokes Recorder measures sunshine in hours and minutes. anemometer wind vane 20 21 Climate Zones Activities Why are there different types of natural scenery all over the world? 1. Look at the climate map of Spain and answer the questions. The answer is climate. The world has several climate zones defined by the climate conditions that 1. Which area in Spain has mild summers? exist in each region. This classification is based on two main climatic variables: the average annual temperature and the total annual precipitation. Climate graphs show the annual temperatures on a curve and the rainfall in a series of bars for all the months of the year. 2. How many types of climates are there in Andalusia? 1. Warm climates are located between the Tropics of Cancer and Capricorn. They have high temperatures throughout the year. 3. Describe the climate in central Spain. Equatorial Climate • Singapore • The equatorial climate is located near the equator. This area is hot mm °C (average temperature 27°C) and humid all year long. There is about 300 30 250 25 4. What kind of vegetation can be found along the 2,000 mm total rainfall. These hot and wet conditions are perfect for 200 20 Mediterranean coasts? the tropical rainforest, which has dense and diversified vegetation. 150 15 • The tropical climate is situated between the Tropics and the equator. 100 10 50 5 Oceanic climate Mountain 5. Identify at least four places on the map with a mountain climate. Tropical areas are hot and wet almost all year. There are only two 0 0 Continental Semi-arid seasons: the rainy season and the dry season. The most common J F M A M J J A S O N D Mediterranean Desert Climate • Shuwaikh, Kuwait type of scenery here is the tropical savannah. mm °C 100 40 80 • The desert climate has hot temperatures and it is dry all year.