Currents Flashcards
What is on each side of the equator?
cell
Two cell names
Polar and Hadley
Why do we have geostrophic wind?
Because we are a sphere
Describe geostrophic wind
- Air flows away from high pressure due to pressure gradient force
- But the Coriolis force causes air to turn right (in northern, left in southern)
- Until a balance is met between the Coriolis force and the pressure gradient force
- This balance produces a balanced flow called a geostrophic wind/ current nearly parallel to the isobars
Hadley
Winds from NE to SW
Atmospheric eddies
A front separates warm and cold air
The warm air is pushed onto the cold air, a low pressure system is created, the isobars are squeezed together, stronger pressure gradient force, stronger wind
High pressure system eddie
clockwise
Low pressure system Eddie
anti clockwise
How does wind impact the ocean?
The large wind fields will transfer energy through friction into the ocean and therefore create surface currents
Due to ekmann transport icebergs will move to the right as they are at depth
Sea surface height
Water will be pushed by the wind and create highs and lows in the ocean, this causes a 2/3m bump in the ocean
Geostrophic currents
- Water flows away from high pressure due to pressure gradient
- the Coriolis force causes water to turn
- a balance is met
- balance produces a balancced flow
Eddies
- Strong current meanders
- Amplitude increases
- A loop is formed
- And pinched off
What causes the great ocean conveyor belt?
Surface currents and thermohaline circulation