1A - Weather Hazards

Sinking air =

High pressure --> high is dry

Rising air =

Low pressure --> low = rain will flow

Cells of atmospheric circulation in order

(sinking air = high pressure) - 90

POLAR

(rising air = low pressure) - 60

FERREL

(sinking air = high pressure) - 30 N

HADLEY

(rising air = low pressure) - 0 degrees (equator)

HADLEY

(sinking air = high pressure) - 30 S

FERREL

(rising air = low pressure) - 60

POLAR

(sinking air = high pressure) - 90

UK weather mix

Cloudy and wet as cold polar air meets subtropical south air. Surface winds from south-west brings warm and wet weather

Conditions for Tropical Storm

- >27 degrees Celsius

- Summer/Autumn

- 5-15 degrees N/S of equator (not enough spin (Coriolis effect) at the equator, or higher than 15)

- Tropical region - requires intense heat + humidity which makes the air UNSTABLE

How do Tropical Storms form? (5 steps)

1. The air above the warm ocean is heated to >27 degrees and warm air rises creating an area of very low pressure

2. As air continues rising it cools and condenses which releases heat (exothermic), which draws up more water vapour from above the ocean

3. The condensing air forms large thunderstorm clouds which join together to form a rotating storm

4. Coriolis effect spins the storm over 75mph and it forms an eye (rapidly sinking air = high p = dry = calm) and the clouds produce heavy rainfall

5. Winds carry storm and it gathers more heat energy and loses it at land (supply of energy cut off - the ocean)

Typhoon Haiyan 2013 (Philippines NEE) IMPACTS (3)

Category 5 - 170mph strongest wind

PRIMARY:

- 6,300 dead

- 90% Tacloban destroyed by 5m storm surge

- Flooding from 400mm rain

SECONDARY:

- Flooding caused landslides --> road block

- 6 million lost jobs

- Looting & violence in Tacloban

Typhoon Haiyan 2013 (Philippines NEE) RESPONSES (2,3)

SHORT TERM:

- USA sent search+rescue teams

- NGOs sent shelter kits and medics

LONG TERM:

- Roads repaired with money from UN

- WHO vaccinated children

- Oxfam replaced fishing boats

Monitoring + Prediction against Tropical Storms

- Satellite tracking

- Prediction maps allowing warnings to be issued like Philippines government sent warnings based on severity of wind and time expected

Protection against Tropical Storms

- Buildings made of strong concrete

- Shutters over windows

- Built on stilts + raised ground in case of flood

Planning for Tropical Storms

Educating and media campaigns to keep people aware of the dangers so they're able to respond

UK extreme weather events

- Thunderstorms --> flash flooding

- Prolonged rainfall --> flooding

- Drought and extreme heat (2003 heatwave killed 2,000 + roads melted)

- Heavy snow and extreme cold

- Strong winds

Somerset Levels - Where and 3 causes of flood 2014

- Wetlands in SW UK

- Drainage basin for many rivers like Parrett

CAUSES:

- Rain - from series of depressions - wettest Jan in history

- High tides - caused by depressions - brought storm surges and high seawater levels which stopped freshwater draining out to sea

- Dredging - hadn't happened in 20 yrs

Somerset Levels 2014 Floods IMPACTS

So/Ec/En (2)

SOCIAL:

- 600 homes flooded

- Villages cut off, people stranded

ECONOMIC:

- £10million damage

- Roads cut off, people couldn't work

ENVIRONMENTAL:

- Sewage + pollutants contaminated water

- Destroyed habitats

Somerset Levels 2014 Floods RESPONSES (3)

SHORT TERM:

- Flood warnings --> told to evacuate

- Sand bags to reduce damage

- Residents moved valuables upstairs

LONG TERM: (Flood Action Plan)

- Dredging river Tone + Parrett

- Bridgewater tidal barrage

- Drain enhancements + road raising