Weather Hazards Flashcards
What is global atmospheric circulation?
- Sinking air creates high pressure and rising air creates low pressure
- Surface winds move from high to low pressure transferring heat and moisture from one area to another
- These winds curve due to the Earths rotation and change seasonally as the tilt and the rotation of earth cause changes in position of the sun
Why is it hot and dry in the deserts?
Because most deserts are found at about 30 degrees north and south where sinking air means high pressure, little rain, hot daytime temperatures and cold nights.
Why is it hot and sweaty at the equator?
Because low pressure marks where the sun is directly overhead. Hot humid air rises, cools and condenses, causing heavy rain - hence the tropical rain forests.
What is a tropical storm?
- They are huge storms called hurricanes, cyclones and typhoons in different parts of the world.
- They form 5-15 degrees north and south of the equator
When do tropical storms form?
- When ocean temperatures are highest above 27 degrees
- The spinning Coriolis effect of the earths rotation is very high
- Intense heat and humidity makes the air unstable
What is the first step of how TS form?
Rising air draws evaporated water vapour up from the ocean surface which cools and condensed to form towering thunderstorm clouds
What is the second step of how TS form?
The condensing releases heat which powers the storm and draws up more water vapour
What is the third step of how TS form?
Multiple thunderstorms join to form a giant rotating storm
What is the fourth step of how TS form?
Coriolis forces spin the storm at over 120 km/h (75 mph) creating a vast cloud spiral with a central calm eye of rapidly descending air
What is the fifth step of how TS form?
Prevailing winds drift the storm over the ocean surface is like a spinning top gathering strength as it picks up more and more heat energy.
What is the final step Of the formation of a TS?
On reaching land the energy supply ( evaporated water) is cut off and the storm will weaken
How will climate change affect tropical storms?
- Over the last couple of decades Sea surface temperatures in the tropics have increased by 0.25 - 0.5 degrees Celsius
- In the future tropical storms may become more powerful
When and where did typhoon haiyan take place ?
November 2013 and In Tacloban
Name 3 of the PE of TH?
- 6300 killed - most in storm surge
- Over 600 000 displaced
- 40 000 homes destroyed or damaged
- Wind damage to buildings, power lines and crops
- Over 400mm of rain caused widespread flooding
Name 3 of the SE of TH?
- 14 Million affected included 6 million jobs lost
- Flooding caused landslides - blocking roads and restricting access for aid workers
- Shortages of power, water, food and shelter, leading to outbreaks of disease
- Infrastructure including school destroyed
- Looting and violence in Tacloban
