Global Temperatures, weather, climate change Flashcards
In an area of land where it’s mainly forest, what will the pressure be and why?
Low pressure because dark surfaces absorb sunlight which is converted to heat so the land heats up quickly in the summer causing air to rise
What kind of pressure forms over the sea and why?
High pressure because it takes more time to absorb heat as it’s a light surface and so air remains cooler and denser causing it to sink
What is the albedo effect?
Where light surfaces reflect more solar radiation and dark surfaces absorb more solar radiation
Why is the North Pole colder than Africa?
As it’s further from the equator and so the solar radiation has to hit it at an oblique angle and has to travel further so it’s less concentrated
What is climate?
The average temperature and precipitation over a long period of time.
What is the Gulf Stream?
Warm ocean currents driven by westerly winds
Describe where the Gulf Stream begins and its movements.
It begins in the Gulf of Mexico blowing north east where a branch heads towards Europe and then becomes the North Atlantic drift
What keeps sea temperatures in January at a reasonably warm 11°?
The North Atlantic drift
What happens to the North Atlantic drift once it reaches Greenland and northern Canada?
It cools and turns south forming Labrador currents
Describe the formation of the currents in the ocean in terms of convection currents starting with the North Atlantic
- North Atlantic water is cold, heavy and quite salty so it sinks
- This sets up convection currents which drags surface water down
- The convection current draws warmer salty water I bet the ocean surface from areas near the equator such as the Gulf of Mexico
- This then cools and sinks in the Labrador and Greenland seas and then flows south towards the equator where it’s warmed again
Why are their icebergs near Newfoundland?
Due to cold Labrador currents moving towards the Gulf of Mexico
What is the global circulation model?
A theory that explains how the atmosphere operates in a series of 3 cells each side of the equator
Why does the atmosphere mean the equator is warmer than the poles?
Because the atmosphere contains particles that absorb heat and at the equator, solar radiation passes through the atmosphere at a direct angle so less heat is lost
State the cells in order of the earth.
Polar cell Ferrel cell Hadley cell Hadley cell Ferrel cell Polar cell
What does air do at the Hadley cell and what’s its effect?
The air at the Hadley cell is warm and rises towards the poles where it then sinks causing high pressure
Describe the movement of air based on the global circulation model
Cold air at the poles moves towards the equator and warms up causing it to rise again
Describe the Hadley cell, thermally direct or indirect?
- The Hadley cell is where warm air travels to around 30° north where it cools and sinks to the surface before returning to the tropics. This creates an area of Hugh pressure
- the cell is thermally direct
Describe the polar cell, thermally direct or indirect?
It’s much smaller than the Hadley cells and is where cold air sinks at the North Pole and then flows south at the surface. At around 60° north, the air is warmed by contact with the land or ocean here and begins to rise
Thermally direct
Describe the ferrel cell, thermally direct or indirect?
It’s found between the Hadley and polar cells that lie between 30° and 60° north
It’s thermally indirect as it’s powered by two other cells
What’s the atmospheric cell over the uk?
The ferrel cell
What cell is responsible for bringing the uk cold and wet weather?
The polar cell as the cold air from here sinks down moving towards the equator
Which cell is the largest?
Hadley cell
