Weather hazards Flashcards
What is the order of cells going from top to bottom
Polar
Ferrel
Hadley
Hadey
Ferrel
Polar
What is global atmospheric circulation
The transfer of heat from the equator to the poles by the movement of air
Why does air move
Differences in air pressure
Global atmospheric circulation summary
Sun warms equator causing air to rise
Air cools as it moves away from the equator
Cool air sinks creating a high pressure belt
Then the cool air either moves back to the equator as trade winds or towards the poles as westerlies
At 60 north and south of the equator the warmer surface meet colder air from the poles
Warm air rises creating low pressure
Some of the air moves back towards the equator and the rest back to the poles
At the poles the cool air sinks creating high pressure and the high pressure air is then drawn back towards the equator
Where do tropical storms form
Between 5 and 30 degrees north and south of the equator
and where the sea temperature is 27 degrees or higher
How do tropical storms form
Warm surface water evaporates and condenses into clouds
The rising air creates an area of low pressure which increases surface winds
Move west due to easterly winds
Spin because of Coriolis
Energy from the warm water strengthens the storm as it moves
When do the majority of storms occur in the Northern/Southern hemisphere
Northern - August to October
Southern - December to April
Features of a tropical storm
Eye is at the centre and up to 50km across
Very low pressure in the eye
Eye is surrounded by the eye wall where there is spiralling winds
Towards the edge of the storm the wind speed falls and the clouds become smaller and more scattered and the rain and temp decrease
When was Typhoon Haiyan
November 2013
Name one of the worst affected areas in Typhoon Haiyan
Tacloban
Primary effects of Typhoon Haiyan
Over 6300 deaths
Over 1 million homes were damaged or destroyed
1.9 million people were made homeless
Flooded 600,000 ha of farmland
Secondary effects of the Typhoon
Several landslides were triggered
5.6 million workers lost their jobs
Lack of clean water caused outbreak of diseases such as dysentery
Immediate responses to the Typhoon
PAGASA (Philippines’ meteorological agency) broadcast warnings of the typhon 2 days before it hit. This led to the evacs of 800k residents before the storm
Plan International constructed pit latrines for 100k people to prevent spread of disease
The RAF donated 200 tonnes of aid
What were long-term responses to the Typhoon
The UN appealed for over $300 million to help fund rebuilding
Storm resistant houses were built
The government planned on building a 4m dike in Tacloban to help reduce the affect of future storm surges
How might climate change affect tropical storms
Frequency - temps will stay higher for more of the year
Distribution - more areas may experience storms
Intensity - more surface evap and more energy
In the Atlantic the number of major hurricanes has doubled since 1970
Examples of different weather hazards in the UK
Strong winds - Storm Ali in 2018 killed 2 people with winds over 100mph blowing over trees
Heavy rainfall - Part of South Wales flooded in 2018 after over 180mm of rain fell in 48hrs
Snow and ice - 2018 Beast from the East brought up to 50cm of snow
Drought - 2022 had only 62% of the usual summer water - hosepipe bans
Thunderstorms - July 2014 a series of thunderstorms struck central England causing power cuts and delaying flights
Heat Waves - July 2022 with temperatures exceeding 40 degrees in Lincolnshire
What is happening to the UK weather (extremity)
It is becoming more extreme
Temp:
The UK’s warmest 10 years have all occurred since 2002
Rainfall:
December 2015 was the wettest month ever recorded in the UK
When were the Somerset Level floods
From December 2013 to February 2014, Somerset experienced 3x the average rainfall for those months
The rivers hadn’t been dredged so the reduced capacity meant that extensive flooding of the levels occurred
Impacts of the Somerset Level floods
Social:
More than 600 homes were flooded
Villages such as Muchelney were cut off by road
Insurance prices soared
Environmental:
11.5 thousand ha were flooded - destroying crops
Decreased the long term fertility of the land
Economic:
Total damage over £80 million
Local companies lost more than £1.2 million in business
Loss of tourism cost the county more than £200 million
Management strategies used by Somerset to reduce flood impact/risk
Before flood:
Warning systems such as the Met Office told people to find accommodation
Sand bags and floor boards to limit damage
After flood:
Somerset Levels and Moors Flood Action Plan - 20 year plan which aims to reduce the risk of future flooding by:
Regularly dredging the rivers Parrett and Tone
Building a tidal barrage at Bridgwater
Widening the River Sowy’s channel
