Weather Hazards and Climate Change Flashcards
(66 cards)
Define climate change.
The changing of the average climatic conditions of the planet over time.
What are interglacial and glacial periods?
Interglacial = warmer
Glacial = colder
What is the Global Atmospheric Circulation System?
The pattern of the movement of air across the planet and how it affects climate
When did the Quaternary Period begin?
~2.6 million years ago
What is a typhoon?
A tropical storm in the Indian or Western Pacific Ocean regions.
What is a tropical cyclone?
Large, rotating storm that forms over oceans in tropical areas
What is eccentricity?
The path of the Earth as it orbits the sun - it departs from a perfect circle at certain periods
How does eccentricity affect climate?
Circular movements cause interglacial periods, whereas elliptical cause glacial - further from sun.
Every 100,000 years, the Earth’s orbit goes from circular to elliptical and back again.
What is the axis tilt?
Earth changing on its axis between 21° and 24.5°.
How does the axis tilt affect climate change?
Earth on greater angle = greater variation between summer and winter.
What are precession cycles?
The natural “wobble” of the Earth. A cycle takes around 24,000 years.
How do precession cycles affect the climate?
Closer to sun = more solar radiation so hotter, affects seasons
What causes precession cycles?
Tidal forces exerted on Earth by the moon and sun
How do solar variations affect the climate?
Sunspots:
More sunspots = higher temp.
Less = lower temp.
How does volcanic activity affect the climate?
Eruptions can blast huge amounts of ash, gas and liquid into the atmosphere.
1. Ash blocks sun = reduces temperatures.
2. Droplets are created which act like tiny mirrors, reflecting radiation from the sun.
What is the Coriolis Effect?
The effect of the Earths spinning on its axis.
How does wind affect heat circulation/climate?
When hot air rises, wind is drawn in. It is typical of low pressure.
How do jet streams affect heat circulation/climate?
Bands of fast-moving air:
More jet streams = area has more variation in weather.
Less = area has more similar weather for longer periods of time.
How do oceans affect heat circulation/climate?
- Ocean currents: North Atlantic drift carries warm water, creating warmer climate in West.
- Warm water is less dense so rises, heats at the equator and moves towards the poles
- This water sinks and moves towards equator.
Why is there low pressure at the equator?
Hadley cells meet - warm air rises, cools and condenses to form clouds.
What sort of climate is created by areas of low pressure?
Rainy
What sort of biome is along the equator?
TRF
What sort of biome is created where the Hadley cells meet the Ferrel cells?
Desert
What happens where the Hadley and Ferrel cells meet?
- Cold air from Hadley cell sinks
- Which traps warm air beneath - cannot rise
- Warm air cannot form clouds so there is no rainfall
- Forms deserts