Starter Activity  Write your name on the Jotter  Write “exam questions examples” on jotter  Stick the sheet on the table neatly in your jotter (fold it in half and stick in the centre of the page lengthways )

Weather and Climate

Factors effecting temperature in the UK There are a number of factors that effect the temperatures in the UK Latitude Aspect Relief Distance from the Sea

Latitude  Latitude describes how far a place is from the equator. Islay is ° North of the Equator. St Ives in Cornwall is ° North.  The suns rays bring less heat to Islay because..  They are at a lower angle and pass through more atmosphere and the clouds gas and dust absorb the heat.  At a lower angle they are spread out over a wider area so there is less heat and any one place

Copy this diagram

Relief  Temperatures decrease by one degree for every 100 metres in height

Aspect  Is the direction that the and faces. Places facing south are warmer than those facing north, because  They receive more heat from the sun when it is in the south and at its warmest  They are sheltered from cold northerly winds

Copy this diagra m

Distance from the sea  In the winter it is warmer in the west on the UK because The Atlantic Ocean is warmer than the land because water cools down more slowly than the land The Atlantic drift makes the temperatures even milder The prevailing wind is from the south west which brings warm winds  In the summer it is cooler in the west because the ocean takes longer to heat up than the land

Factors affecting rainfall

Relief  The height of the land affects rainfall as well as temperature  Upland areas receive more rainfall than lowland areas Aspect The hillside that faces the moist wind will receive the most rain. On the leeward side there is very little rain this is called the rainshadow Distance from the sea Most of the water vapour in our air has come from the Atlantic ocean so places on the west get the most rain and those on the east the least

Copy this diagra m

You now have some questions to answer  Homework will be to complete the living graph

Starter Activity Quick write 10 mins of silent writing and or diagrams on the topic of weather so far – using the piece of paper on your desk

Air Masses effecting the UK  By the end of the lesson you will be able to explain What an air mass it (national 4) Describe what type of weather each brings (national 4 and 5) Describe differences between two (national 4 and 5) Give reasons for the weather bought by one of the masses (national 5) Justify the type of weather that one of the air masses is responsible for (national 5)

Questions  Polar maritime air masses develop over cold oceans. Describe where out other four air masses develop.  Describe the weather associated with Tropical Maritime Air  Give reasons for the weather brought by Artic Maritime  Compare the weather brought by Tropical Continental and Polar continental air masses  Which Air mass is responsible for most of the rain we receive in the UK? Justify your answer

Depressions  Understand how a depression is formed  Know the main features of a depression  Know the weather found in different parts of a depression

Formation of a Depression Where the Tropical Maritime and Polar Maritime masses meet is called a front The front is not a straight line but wavy and warm air makes a wedge into the cold air (stage 1)

The two masses have different densities so do not mix – so the warm air rises over cold air and creates a low pressure area (stage 2)

 Winds blow around and towards the centre of the depression in an anticlockwise direction  This are of low pressure is called a depression  As the cold front and cold air forces warm air upwards so that the cold front gets nearer and nearer to the warm front eventually the cold air forces upwards all the warm air into the warm sector and the cold front meets the warm front. This is called an occluded front.

Time for a video

Pat does depressions

Warm Front Area of low pressure Cold Front Pat

Describe the direction of air flow in a depression.

Warm Front Cold Front Warm Sector Low Pressure Draw the direction of air flow Where Is Pat?

Why are there showers here? Frontal Convection or Relief rainfall. Why are there clouds here? Why is it clearer here?

Warm FrontIntermittent ShowersNimbostratus Clouds Cirrus Clouds Warm Sector Cold Front Continuous RainShowers after the Cold Front Rain, Thunder and Lightening Cumulonimbus clouds 1 2

Complete the paragraph in your jotters When cold air meets warm air, the cold air is forced to sink under the warm air, this is because it is more dense. As the cold air sinks it forces the warm air to rise. As the warm air rises, it cools, condenses, forms cumulu-nimbus clouds and rains. This collision of air is particularly violent, often there may be thunder and lightening. When warm air meets cold air, the warm air is forced to rise over the cold air, this is because it is less dense. As the warm air rises, it cools, condenses, forms nimbo-stratus clouds and there is continuous rainfall

In your Jotters write down as four weather conditions that u can see in these pictures

You should have spotted These are all characteristic of winter Anticyclonic conditions.

HIGH PRESSURE SYSTEMS High pressure systems are also known as anticyclones

The Earth’s surface The Earth’s atmosphere presses down on the surface of the Earth. HIGH ATMOSPHERIC PRESSURE Cold, dense air falls. This increases the weight of the air pressing down on the Earth’s surface.

WHAT CAUSES HIGH PRESSURE? When air high in the atmosphere is cold, it falls towards the earth’s surface. Falling air increases the weight of air pressing down on the Earth’s surface. This means that air pressure is high.

WHAT WEATHER DOES HIGH PRESSURE BRING? As the cold air falls through the atmosphere, it becomes slightly warmer. Because warm air can hold more moisture than cold air, no condensation or clouds occur. This means that high pressure systems bring clear skies. Winds are usually light, and blow out of the high pressure area. There are no warm or cold fronts in high pressure areas.

HIGH PRESSURE IN WINTER High pressure in winter gives us clear skies very low temperatures calm, or light winds no precipitation frosty conditions

HIGH PRESSURE IN SUMMER High pressure in summer gives us clear skies high temperatures calm, or light winds no precipitation © Microsoft Word clipart

1.Rain, snow, sleet and hail. 2.A line that joins equal points of pressure. 3.Some surfaces reflect more heat than others. 4.It becomes cooler the higher you go. 5.It will bring warm and wet weather. 1.What is precipitation? 2.What is an isobar? 3.What is albedo? 4.How does relief affect temperature? 5.What weather will a tropical maritime air mass bring?