Tuesday, 31 January 2017

Types of rainfall


There are three common types of rainfall, all of which occur in Spain. All have the common theme of air being forced to rise.
As air rises it cools it cannot hold as much moisture as it could when it was warmer. Eventually the rising air reaches a point where it is 100% saturated, in other words it cannot hold any more water. This is called dew point, and it is above this point that condensation occurs.
Condensation is the process by which the water vapour (a gas) held in the air is turned back into water droplets (a liquid), which fall as rain.
Very common in areas where the ground is heated by the hot sun, such as the Tropics. This is why those areas experience heavy rainfalls most afternoons. The United Kingdom does experience some convectional rainfall during the summer, particularly in the South East of the country.
Convectional rainfall occurs when:
  • The surface of the earth is heated by the sun.
  • The warm surface heats the air above it. Hot air always rises so this newly heated air does so.
  • As it rises the air-cools and begins to condensate.
  • Further rising and cooling causes a large amount of condensation to occur and rain is formed.
Convection tends to produce towering cumulo-nimbus clouds, which produce heavy rain and possible thunder and lightning.

The United Kingdom experiences a lot of frontal rainfall, as it is associated with the movement of depressions over the country, which are described in more detail elsewhere in this topic.
Frontal rainfall occurs when:
  • Two air masses meet, one a warm air mass and one a cold air mass.
  • The lighter, less dense, warm air is forced to rise over the denser, cold air.
  • This causes the warm air to cool and begin to condense.
  • As the warm air is forced to rise further condensation occurs and rain is formed.
  • Frontal rain produces a variety of clouds, which bring moderate to heavy rainfall.



This is also called orographic rainfall, which is very common in the United Kingdom, especially on the West coast since the prevailing weather comes from that direction.
Relief Rainfall occurs when:
  • The prevailing winds pick up moisture from the sea as they travel across it, making the air moist.
  • The moist air reaches the coast and is forced to rise over mountains and hills.
  • This forces the air to cool and condense, forming clouds.
  • The air continues to be forced over the mountains and so it drops its moisture as relief rain.
  • Once over the top of the mountain the air will usually drop down the other side, warming as it does so. This means it has a greater ability to carry water moisture and so there is little rain on the far side of the mountain. This area is called the rain shadow. ( link to this material)
Activity: Read the texts. Prepare these materials with your words to explain the different three types of rainfall that there are.  You can use this other link

Monday, 30 January 2017

Vocabulary. Unit 4

Weather: It refers to the state of the atmosphere in a place at a specific time.
Climate: It refers to the state of the atmosphere in a place over a long period of time.
Weather station: The place where it studies the weather and climate.
Axis: It is the point where the Earth rotates.
Orbits: It is the way that follows the Earth in her revolution around the Sun.
Cold zone: It is the zone whithin the polar circle. In this area, the temperatures are always cold.
Latitude: It consists that the areas near the Equator rain more than the other areas.
Altitude:It consists that it rains more in high areas than in low areas.
Inland climates: It is a climate which is much hotter in summer and much colder in winter.
Humidity: It is amount of water vapor in the air.
Anticyclones: It is areas with a high pressure.
Depressions: It is areas with a low pressure.
Anticlockwise: It is the opposite sense to the clock wise.
Average temperature: It is the average of the temperatures in an area.
Maximum temperature: It is the highest temperature of an area.
Minimum temperature: It is the lowest temperature in an area.
Jet Stream: It is a wind that blows from east to west and it is found in the temperate zones.
Global wind patterns: It is the group of every winds on the Earth.
Doldrums: It is a place where the wind don't blow
Sea breeze: It is a type of synoptic winds which is blowing from the sea towards the land by day.
Rotation: It is when the Earth spins on a imaginary straight line called axis.
Revolution around the Sun: It is the movement of the Earth around the Sun. That produces the year and the seasons.
Equinoxes: It is the moment that mark the beginning of Autumn and spring
Solstices: It is the moment that mark the beginning of winter and summer.
Thermometer: It is the tool necessary to measured the temperature.
Hot zone:It is the zone where the Sun's rays reach the earth in perpendicular angle all year round, so temperatures are always high.
Temperate zone: It is the zone between the tropics and polar circle. In this area the temperatures are temperate.
Precipitation:It is droplets that fall on the Earth's surface.
Convectional rain: This is a type of rainfall characteristic of hot climates.
Orographic/ Relief rain: This is a type of rainfall characteristic of mountains regions.
Frontal rain: This is a type of rainfall takes place at the boundary, between a mass of warm air and a mass of cold air.
Front: It is the boundary between different air masses.
Atmospheric pressure: It is the force exerted at a specific point on the Earth´s surface by the weight of the air above it.
Prevailing winds: These winds always blow in the same direction.
Periodic winds: These winds change direction seasonally.
Seasons:Different moments around the year when temperatures and rainfalls change. It are produced with the orbit of the Earth.
Synoptic winds: These winds change daily.
Trade wind: These are winds influenced by the surrounding geography.
Water vapor: It is the water evaporated.
Land breeze: It is a type of breeze given in the land.

Monday, 23 January 2017

Interpreting a weather map

Today's weather forecast map for Europe
Metereologits make weather maps with data sent by satellites. A weather map usually includes information about atmospheric pressure at sea level.
  • Isobars are the lines connecting points of equal pressure
  • The H indicates high pressure
  • The L indicates low pressure
  • Fronts are drawn with jagged line
  • Wind sometimes are represented by arrow.
  • The closer the isobars are to each other, the stronger the wind are.
TASK
Explain what the following represent.
  • The lines
  • the letters H and L
  • The jagged lines
Describe what the weather will be like
  • In hight pressure areas
  • In low pressure areas
  • In areas affected by a front
Link:

Tuesday, 17 January 2017

Environmental Problems´ Presentation

We will go to make a Power Point about the environmental problems. You can look for ideas  in  your book, pag 64-65 or in these links:
These  presentations will make in  groups of 2 people. You send me your work.  Some groups  show us your presentation in class.

Thursday, 12 January 2017

How does the climate system work?

 
Task
Make a Summary after heard and watch the video, send me the summary

Tuesday, 10 January 2017

Cimate Science in a Nutshell #2: What is Climate?

Vocabulary Unit 4. Weather and climate


Unit 4
  • Weather
  • Climate
  • Meteorology
  • Cold zone
  • Latitude
  • Altitude
  • Inland climates
  • Humidity
  • Anticyclones
  • Depressions
  • Anticlockwise
  • Average temperature
  • Maximum temperature
  • Minimum temperature
  • Anemometer
  • Global warming
  • Droughts
  • Thermometer
  • Hot zone
  • Temperate zone
  • Precipitation
  • Convectional rain
  • Orographic / relief rain
  • Frontal rain
  • Front
  • Atmospheric pressure
  • Prevailing winds
  • Season
  • Trade wind
  • Water vapour
  • Greenhouse efect
  • Fossil fuels
  • Climate change
  • Flooding
Homework:
    You need to know these words and your meanings for the next exam. I´m going to ask you.

    The atmosphere

    We explore about the atmosphere in this page and you talk with Ross about that.

    We make the different activities in these points:
    1. COMPOSITION OF THE ATMOSPHERE.
    2. THE LAYERS OF THE ATMOSPHERE
    3. IMPORTANCE OF THE ATMOSPHERE.
    4. THE WEATHER.