1.1 Climate Flashcards
Global atmospheric circulation model
Which part of the earth receives more sunlight?
- the earth receives unequal heating
- the equator receives more sunlight, and more heat
- the poles receives less sunlight, and less heat.
Global atmospheric circulation model
Where are each cells?
Hadley cells: at the equator
Ferrel cells: besides the Hadley cells
Polar cells: at the North and South poles.
Global atmospheric circulation model
What happens at the Hadley cells?
- warm, moist air at the equator rises (because of sunlight/heat)
- as it rises, it cools and condenses, creating heavy rainfall at the equator
- rainforests on the equator
- as air moves towards the pole, it cools and sinks at the tropics. brings warm, dry air to the tropics - creating deserts.
Global atmospheric circulation model
What happens at Ferrel cells?
- as it moves towards higher latitudes, it meets cool air (returning back to the equator)
- forces the air up at 60 degrees, creating an area of high rainfall
- air carries on towards the poles
Global atmospheric circulation model
What happens at the Polar cell?
- air sinks
- moves back to the equator
Global atmospheric circulation model
Global atmospheric circulation model summary
- warm, moist air rises (low pressure)
- air cools & condenses, creates heavy rainfall and high pressure (rainforests)
- sinks at tropics. brings warm dry air = deserts at tropics
- air meets cool air. air is forces up - creating an area of high rainfall
- sinks at the poles. air moves back to equator.
Which direction does ocean currents work in?
- warm waters from the equator travel towards the poles, near the surface of the oceans.
- cooler water (which carry nutrients) travel from poles to the equator
Natural causes of climate change
Volcanic eruptions
When a large volcano erupts, it launches ash and dust into the atmosphere. This blocks the sunlight reaching the surface, so the Earth’s temperature drops, leading to an ice age.
Natural causes of climate change
Sunspot theory
- dark spots on the sun which means that the sun is working harder to produce more energy
- generates slightly more heat which increases the temperature
Natural causes of climate change
Orbital theory
- Circular orbit: temperature increases because the Earth is closer to the sun
- Elliptical orbit: temperature decreases because Earth is further away from the sun
- Tilts: equator gets more sunlight, poles become cooler (less sun)
Natural causes of climate change
Albedo effect
- Lighter colours reflect more light/sun than darker colours (absorbs heat)
- a lot of ice coverage reflects light and heat, creating a cooling effect.
- when the ice melts, it exposes the darker ocean water underneath, which absorbs the heat and increases temperature.
Evidence of natural climate change
Ice cores
- when snow falls, it traps air into the ice
- when scientists take a core of ice, it reveals the gas concentrations of when the snow fell
- used to calculate temperatures of that time
- rapid increase in temperature in the past decades.
Evidence of natural climate causes
Tree rings
- every year, a new ring forms in the trunks of trees.
- tree rings are thicker in warm, wet conditions.
- they are a reliable source of evidence for the past 10,000 year
Evidence for natural climate causes
Historical sources
- Temps were measured and recorded globally using thermometers since 1850s.
- The record is highly reliable but very short term.
Human causes to climate change
Greenhouse effect and the enhanced greenhouse effect.
- atmosphere naturally traps radiation from the sun, allowing Earth to be habitably warm.
- humans have enhanced the natural effect and more heat is being allowed in, but less is able to escape the atmosphere, **creating a warming effect. **
