Atmosphere - Rotation Dynamics Flashcards
What is distribution of climate a function of?
Earth shape, eccentricity, solar constant and rotation.
What does Earth tilt result in?
Seasonl-monthly change
What are the three keplar laws?
Orbit of each planet is an ellipse with the sun at one focus
Orbital radius of a planet sweeps at equal areas of the ellipse
Ratio of the square of a planets period to the cube of the semi-major axis of its orbit is constant for all planets
Semi-major axis
This, alongside the minor axis, is the major axis of an ellipse.
What do three laws depend on respectively?
Conservation of energy
Conservation of angular momentum
Gravity/Centrifugal force
Gravitational Constan
This is the force of attraction between two unit masses seperated by a distance
What are the two points of an ellipse?
Perihelion
Aphelion
Perihelion
The closest approach to the sun
Aphelion
The point further from the sun
What does hadley cell transport?
Eastern angular momentum to mid latitudes
What leads to development of subtropical jet stream?
Hadley subsidence
Subtropical jet stream
A belt of strong upper-level winds lying above regions of subtropical high pressure
Why do jet streams form?
From cold air masses meeting warm air masses
Jet Stream
A powerful current encricling the globe in NH and SH 10-15km above surface
What doe jet streams do?
Create areas of low and high pressure, moving these systems from west to east.
What is direction of jet stream driven by?
Coriolis force and temperature differences
Rossby Waves
Meandering fluids in troughs and ridges, perturbing straight flow.
Baroclinity
A stratification of a fluid where surfaces of constant pressure intersect surfaces of constant density.
How do jet streams and rossby waves differ?
Jet streams are the paths of flow, rossby waves are the undulations.
Storm Tracks
A course followed by cyclones or storm systems as they move across land or sea.
Eddies
Wind currents around high and low pressure disturbances
How do eddies influence jet streams?
Distribution of temperature and kinetic energy, propelling westerly et streams
What causes lon-linearity of the jet stream?
Surface assymetries and large-scale instability.
How do polar jet streams form?
Undercutting warm, rising sub tropic air by denser, colder polar air masses.
Why do jet streams form in a quasi-geostrophic manner?
No friction, the north-south pressure gradient deflected by coriolis.
Cyclones and Anticyclones
High pressure systems and Low pressure systems
Vorticity
A pseudovector field describing local spinning continuum near some point.
What causes Rossby waves?
Conservation of vorticity
What causes voriticty?
Earth rotation and air mass rotation relative to the earth surface
How are anticyclones formed?
Polweard increase in voricitcy, closer to earths axis, thus increase in vorticity to compensate, spinning opposite direction of Earht.
What causes baroclinic instability?
Meridonal temperature gradients, colder denser air sitting alongside warmer, lighter air
What is turbulence caused by?
Excess kinetic energy in parts of a fluid flow, which overcome the damping effect of the fluid visocity
Where do rossby waves grow?
Vorticity gradients
