Jet Streams Flashcards
What does the Jet Stream do?
Create and move depressions, anticyclones and tropical storms as well as controlling the movement of heat energy and circulation
Give 3 features of Jet Streams?
- Meanders and Perturbations
- Extreme heating/cooling
- Rossby Waves
What is the standard pressure level?
500 hPa
What is used to calculate the height of a pressure surface?
The Hydrostatic Equation
Where do you experience Westerly Jet Streams?
Mid Latitudes
Where do you experience Easterly Jet Streams?
Sub Tropics
What affect do mountain barriers have on jet streams?
Forced them North and South towards the equator
What are Rossby waves?
Long wavelengths in flow
Why is the conservation of vorticity important when looking at jet streams?
It returns the meander to the North and the conservation to the South
Deceleration is associated with….
Convergence
Acceleration is associated with….
Divergence
What does convergence at height give at the surface?
High pressure/Anticyclones
What does divergence at height give at the surface?
Low Pressure/Depressions
What do blocks cause?
Persistent features due to 4-5 standing waves
What are Sting Jets?
A strong, descending flow of cold air found in the centre of a server mid-latitude depression. It can cause damaging winds at the surface.
What is the Jet Stream?
A stream of very fast-moving winds. The polar front jet runs in the upper troposphere in association with the polar front and is a major factor in the growth and dissipation of mid-latitude depressions
What is the polar front?
The boundary in the mid-latitude sphere warm tropical air meets cold polar air
