1. Weather and Climate

2. You will find the following topics in this Slideshow:
The difference between weather and climate.
Microclimates (including the role of aspect, shelter, buildings, surface and natural features)
The global water cycle (including interception, surface run-off and infiltration)
Types of Rainfall (Relief, Convectional, Frontal)
Temperature and rainfall variations in the British Isles (and what causes them).

3. Weather
Weather is the condition of the atmosphere in a place at one moment. It can change from one second to the next.
Weather includes rainfall, temperature, visibility, wind speed, wind direction and cloud cover.
Climate
Climate is the average weather in a place measured over 30 years. It is what we expect in a place.
Climates include Mediterranean, Polar, Temperate, Hot Desert and Equatorial.

4. Microclimates SHELTER ASPECT NATURAL FEATURES BUILDINGS SURFACE
A microclimate is a small area where the climate is different to the surrounding area.
They can be affected by:
SHELTER
ASPECT
NATURAL FEATURES
BUILDINGS
SURFACE

5. ASPECT BUILDINGS SHELTER & NATURAL FEATURES SURFACE
This is the direction a place faces. Places that face the sun are warmer than those that face away from the sun. In the UK (where Common Entrance is written) places with a south-facing aspect get more sun and higher temperatures.
ASPECT
These can change wind speed and direction, creating either calm or very windy areas. On warm, sunny days, buildings absorb heat and give it out at night. This means that cities can have night-time temperatures 2-3⁰C warmer than areas outside the city.
BUILDINGS
SHELTER
Walls, buildings, cars, hedges and trees provide shelter from wind. Sheltered places often feel warmer and also get less rain. Lakes and their shores are often more windy than surrounding areas.
&
NATURAL FEATURES
SURFACE
Dark, artificial surfaces like tarmac warm up faster and give off more heat than light, natural surfaces like grass.

11. The Global Water Cycle Infiltration Groundwater flow or Through flow.
Interception

12. Water Cycle definitions
Evaporation is the process of water turning into water vapour due to warming.
Transpiration is evaporation from tree leaves or plants.
Precipitation is rain, drizzle, snow, sleet or hail.
Condensation is where water vapour cools and turns back into water. In this case it happens high up and forms clouds.
Interception is where precipitation lands on tree leaves etc. and so does not reach the ground.
Infiltration is where the water sinks into the ground prior to experiencing Groundwater flow.
Groundwater flow or Through flow is where water flows downhill under the surface.
Surface run-off (or overland flow) is where water flows downhill overland, mainly in rivers.

13. Types of Rainfall 1. Relief Rainfall 2. Convectional Rainfall
There are 3 types of rainfall:
1. Relief Rainfall
2. Convectional Rainfall
3. Frontal Rainfall

14. 1. Relief Rainfall 4. Condensation occurs and clouds are formed.
5. Precipitation.
3. Air cools as it rises.
2. Air is forced up by high land.
1. Warm, moist air blows in from the sea.

15. 2. Convectional Rainfall
4. Condensation forms clouds
5. Precipitation
1. Sun’s energy heats up the earth
3. Warm, moist air cools as it rises
2. Evaporation and transpiration

16. 3. Frontal Rainfall 4. Condensation forms clouds 5. Precipitation
3. Warm, moist air cools as it rises
2. Warm air rises over the cold air as it is less dense
1. Warm air and cold air meet at a front

17. Temperature and Rainfall in the British Isles
Facts about the British Isles climate:
Wet
Mild Winters
Mild Summers
1. The west is wetter than the east all year round.
Summer prevailing wind
Dry
Cold Winters
Mild Summers
2. In winter, the west is mild and the east is cold.
Dry
Cold Winters
Warm Summers
Wet
Mild Winters
Warm Summers
3. In summer, the north is mild and the south is warm.
Winter prevailing wind

18. What causes these variations?
1. The west is wetter than the east all year round.
This is because the prevailing wind is always from the South-West or the West. This brings moisture off the Atlantic Ocean and the mountains down the west coast force this upwards to form relief rainfall in the west. The east is in a rain shadow and so gets less rain.
2. In winter, the west is mild and the east is cold.
Again, this is caused by the prevailing wind, which is from the South-West in winter. This causes the South and West of the British Isles to be slightly warmer as the wind has travelled across the warm Atlantic Ocean to get to Britain.
3. In summer, the north is mild and the south is warm.
This is due to the distance from the equator. The north is further away and hence
cooler. Also, the prevailing wind comes in from the west and so does not have a
cooling effect on the south coast. The north can also be vulnerable to Arctic winds
at times, reducing the temperature there.