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Question 1

hurricane formation

Answer 1

1. evaporation of the sea creates a low pressure area
2. low pressure area draws in low level winds close to sea surface
3. rising air condenses, releasing latent heart, further driving evaporation, condensation and cloud formation
4. cloud formation is not broken up at high altitudes due to low wind shear
5. coriolis force creates hurricane vortex
6. anticyclone in upper troposphere causes wind to exit and sink and recycle into vortex

Question 2

tornado formation

Answer 2

1. ground heated by sun creates upward convection, forcing moist air high into the atmosphere
2. moist air meets cool dry air causing rapid cooling, creating clouds
3. strong wind shear force from opposite direction of convection rotates air
4. updraft tilts cylinder of rotating air , tornado touched ground and moves over land

Question 3

monsoon formation

Answer 3

1. Asian landmass heats up much quicker than the sea during summer
2. subtropical jet stream weakens and moves northwards
3. tropical easterly jet stream forms and creates high pressure system over the Indian ocean
4. moist air flows from high pressure areas over the ocean northwards
5. condenses and causes large scale rains over the foothills of the himalayas

Question 4

rain shadow

Answer 4

1. mountains create a low pressure area
2. clouds and rain form windwards side as warm and moist air rises to meet the low pressure area and expands, cooling down
3. relative humidity hits 100%, triggering strong rainfall
4. non windward side is very dry as the descending air has no moisture left

Question 5

formation of winter storms in the UK

Answer 5

1. polar front jet stream moves further south in the winter
2. jet stream can buckle, forming planetary Rossby waves
3. different weather systems occur over the UK as the waves move over
   - the jet stream brings intense rainfall
   - cold polar air makes it clear and cold (cyclonic)
   - warm tropical air makes it warm and humid (anticyclonic)

Question 6

sudden stratospheric warming

Answer 6

1. in winter a strong polar vortex develops in the stratosphere
2. a large pressure difference between this and the jet stream in the troposphere causes a strong jet stream
3. the vortex can be stabilised by planetary waves crashing into it from the troposphere
4. the collapse of the vortex causes rapid heating in the stratosphere
5. east winds burrow down from the stratopshere and weaken the jet stream in the troposphere
6. this causes a wavy patter in the jet stream
7. this weakens westerly weather systems and increases the chance of northerly and easterly weather systems

Question 7

high plateaux areas

Answer 7

• can interfere with jet stream and disrupt atmospheric circulation by forcing air up and over them and deflecting the weather systems around them
• colder than surroundings in winter, creating anti-cyclonic areas of high pressure above them
• warmer than surrounding in summer, creating cyclonic low pressure areas, driving monsoons