UK climate complete

UK climate complete

1. Location

   • In relation to Atmospheric cells
     • The UK is on the northern edge of the Ferrel cell. surface winds bring warm air from the south, and the warm air rises. this creates a low pressure and causes depressions which can bring rain throughout the year,
   • Maritime location
     • The UK is surrounded by water which gains and heat more slowly than land does. this means there are cool winds blowing from the sea to the land in summer, and warm winds blowing from the land in winter. So the summer is cooler and winter is warmer than inland locations in the same lattitude.
   • located near gulf stream
     • As the UK is located near the Gulf stream, this makes the UK warmer than many places at the same latitude.

2. latitude

   • The UK is at mid Latitude (between 50-55 North) It doesnt get too hot because the sun is very high in the sky. It also doesn't get too cold because there are several hours of daylight even in winter.

3. variations

   • temperetures
     • It's warmer in the South because theres more insolation reaching the ground. this is because the sin is higher in the sky and there are more hbours of day light in the North.
       • E.g Annual average maximum temperature is 13.6 degree in Cornwall and 9.3 C in Scotland
   • precipitation
     • Its wetter in the West than the east. e.g annual average rainfall is 871mm in Blackpool (on the west coast) and 565mm in Cleethorpes ( on the east coast) This is because South Westerly winds bring warm wet air from the Atlantic Ocean, The air reaches the west side of the UK and its forced upwards over land. the air cools, the water condenses and it rains. .
       • This is known as orographic or relief rainfall. The west of the UK is generally more mountainous than the east so the Air masses lose most of thier moisture in the west. The area to the east of the mountains where less rain falls is called rain shadow
   • wind
     • Winds are stronger in the West, e.g the annual wind speed is 21.7 km/h. in St Mawagan (on the South west coast) and 16.7km/h in Marham (on the east coast) this is beccause south westerly surface winds come over the ocean-(the ocean is flat so theres notheing to slow the winds down) ehrn the winds hit land, they're affectted by the hills and become weaker.
       • Winds are stronger in higher altitiudes because there are fewer land florms to slow them down.

4. depressions

   • depressions form over the Atlantic ocean then move east over the UK. they usually form when tropical maritime and polar maritime air masses meet.
     • Warm air constantly moves out of tropical areas towards the poles. A warm front is the leading edge of a warm air mass
       • Cold air moves out of polar regions towards. a cold front is the leading edge of a cold air mass.
         • where Air masses meet, the warm air heading towards the poles rises above the cold air moving towards the tropics (because warm air is less dense than cold)
           • the rising warm air means that atmospheric pressure is reduced. strong winds blow from srrounfing reas of high pressure towards this area of low pressure and the whole systems rotates as air continues to rise.
             • Cold fronts movemore quickly than warm fronts, so the cold front catches with the warm front. when this happens, the warm air is undercut by incoming cold front and is lifted away fro the ground entirely. it now sits above the cold air- this is an occluded front. the warm air rises into the upper atmosphere and the depressions dissolve.

5. Anti cyclones

   • winter weather
     • low temperatures during the day (from bellow freezing 5oC) because the sun is at a low angle.
     • extremely cold overnight temperatures (below freezing) with fronts because clear skies allow loss of hear through radiation.
     • low level cloud and radiation fog- radiation fogs forms overnight. as ground cools moisture n the air close to the ground condenses forming fog.
     • high levels of atmospheric pollution in urban areas- pollutants are trapped by temperature inversions (when the air at higher altitudes is warmer at lower levels) a lack of winds means pollutants aren't dispersed
   • summer weather
     • The absense of clouds leads to intense insolation which means its hot, sunny and there's no rain.
     • rapid radiation at night can cause temperature inversions dew and morning mist
     • coatal areas may get fogs and strong breezes. highlands may experience strong winds due to heating of valley sides which causes a pressure gradient
     • After several days, there's a risk of d, due to large amounts of rapidly rising warm air.

6. What are air masses

   • Air masses
     • Artic Maritime
       • Air masses form over the Artic ocean. they bring very cold wet weather which causes cold weather and rain.
     • Polar continental
       • Air masses form over Siberia (in the Artic) They bring Cold dry air which causes very cold dry weather. These air masses can bring snow if the air picks up moisture from the north sea.
     • Tropical Continental
       • Tropical continental air masses form over Africa. they bring warm dry air which causes hot dry weather.
     • Tropical Maritime
       • Tropical Maritime air masses form over the Atlantic Ocean. They bring warm wet air which causes warm weather and rain.
     • Polar Maritime
       • Polar Maritime air masses for over the North Atlantic Ocean. They bring cold wet air which causes cold weather and rain.
   • Air masses are large volumes of air with similar characteristics mainly from the areas they have traveled over or come from. They cover large areas (several hundred km) and can travel long distances.
     • Artic or plar Air masses form at higher lattitudes so they are colder
     • Tropical air masses form at low latttitudes (so they are warmer)
     • Maritime air masses form over oceans (so have higher water vapour content
     • Continental air masses form over land so they have lower air masses.