weather hazards

• atmospheric circulation

  .sinking air creates high pressure and rising air creates high pressure.

  .surface winds move from high ton low pressure transferring hat and moisture from one area to another

  .these winds curve due to earths rotation and change seasonally
• uk is cloudy ad wet because at 60º north the polar air from the north meets warm subtropical air from the south. these then bring warm and wet weather which rises, cools and condenses forming clouds and rain
• a tropical storm is a huge storm that form between 5º and 15º north and south of the equator when ocean temperatures are above 27ºC, Coriolis effect is very high and intense heat and humidity makes air unstable
• how do tropical storms form

  .rising air draws evaporated water vapor up from the ocean surface which cools and condenses forming huge clouds

  .the condensing releases heat which powers the storm and draws up more water vapor

  .multiple thunderstorms join together creating big rotating storm

  .coriolis forces spin the storm over 120 km/h

  .prevailing winds drift storm over the ocean gathering strength as it picks up more energy

  .on reaching land energy supply is cut off and the storm is weaker
• structure of tropical storm

  eye- small area in the centre and conditions are calm

  eye wall- here are the wrong winds either side of the eye with thunder and lightning
• effect of climate change on tropical storms

  • sea temps have risen so they become more frequent
  • in future they may extend to sub tropics
  • may become more powerful
  • hurricane intensity has increased
• typhoon Haiyan, November 2013

  primary effect- 6300 killed, 600,000 displaced, 40,000 homes damaged

  secondary effects- 14 million effected including 6 million losing jobs, flooding cause landslides, shortages of power+water+food+shelter, looting and violence, infrastructure destroyed

  immediate responses- rapid overseas aid, US helicopter help in search and rescue, 1200 evacuation centers set up

  long term responses- UN financial aid +medical support, rebuilding of infrastructure, fishing and rice farming reestablished, homes rebuilt in safer areas, cyclone shelters built
• reducing effects of tropical storm

  monitoring, prediction and protection- monitored via satellites allow prediction maps. cyclone waring signals and hurricane centers.

  protection- cyclone shelters are built on stilts and have shutters and are reinforced by concrete and built on raised grounds

  planning-educating people at risks and media campaigns
• uk weather hazards

  thunderstorms- follow hot weather bringing heavy rain associated with flash flooding

  prolonged rainfall- leads to river flooding

  drought and extreme heat- can kill people and dries up reservoirs

  heavy snow- can cause difficulties due to traffic

  strong winds- cause disruptions to power services and damage from waves and fallen trees
• Somerset level floods- south west England

  .caused by record high rainfall in jan and feb, river parrot and tone hadn't been dredged in 20 years

  . over 600 houses damaged and 16 farms evacuated, villages cut of affecting businesses, £10 mil in damage, debris clearance needed

  .immediate responses were huge media interest, boats for transportation and volunteers helping

  .long terms responses were £20 mil flood action plan launches, 8km of rivers dredged, road levels raised and river banks strengthened
• extreme weather events are increasing as climate change is getting worse leading to more energy in atmosphere from rising temperatures possibly affecting atmospheric circulation