lecture 11

Question 1

What are atmospheric motions

Answer 1

Atmospheric motions span a wide range of length scales (spatial size), and time scales

Question 2

What are the largest to smallest atmospheric motions?

Answer 2

Largest to smallest: Global scale (Planetary waves, Hadley cell), Synoptic scale (extratropical cyclones, weather systems), Mesoscale (thunderstorms, tornadoes), Microscale (turbulence in clouds, turbulence in the Planetary boundary layer)

Question 3

Planetary scale circulation resulting mostly from:

Answer 3

1. The difference of temperature between the equator and the poles

2. The rotation of the planet

3. Distributions of land and water over the planet

Question 4

The Single-Cell Model:

Answer 4

•Simplified model of the general circulation proposed by Hadley (1735)
• Based on idealized water-planet with no effects of rotation (no Coriolis force)
“Hadley thought heating at the equator caused a circulation pattern in which air expands
upwards and diverges toward the poles, sinks to the surface, and returns to the equator”
• Deflection by Coriolis
• One single cell in each hemisphere
• First model of a thermally driven circulation 


Question 5

The Three-Cell Model:

Answer 5

-Improved model of the general circulate proposed by Ferrel
-Each hemisphere divided into three cells (polar cell, ferrel cell, and hadley cell)
-Not perfect, but more realistic and capable of explaining many of the observed features of the
real circulation