American Meteorological Society Certification Atmospheric Dynamics 2

Question 1

What is the thermal wind relationship?

Accepted Answer

Vertical wind shear is related to horizontal temperature gradients

Answer

The thermal wind relationship states that vertical wind shear in geostrophic flow is proportional to horizontal temperature gradients.

Question 2

Which flow regime is characterized by a small Rossby number and quasi-geostrophic balance?

Accepted Answer

Synoptic-scale flow

Answer

Synoptic-scale systems have small Rossby numbers, making quasi-geostrophic balance a good approximation.

Question 3

What does divergence in the upper atmosphere typically indicate at the surface?

Accepted Answer

Surface low pressure and rising motion

Answer

Upper-level divergence removes mass from a column, lowering surface pressure and promoting rising motion.

Question 4

What is the primary driving mechanism for the jet stream?

Accepted Answer

Horizontal temperature gradients in the troposphere

Answer

The jet stream is driven by strong horizontal temperature gradients, particularly between polar and tropical air masses.

Question 5

In ageostrophic wind theory, what causes air to deviate from pure geostrophic flow?

Accepted Answer

Acceleration, friction, and curvature effects

Answer

Ageostrophic motions arise from accelerations, friction, and curvature terms not captured by pure geostrophic balance.

American Meteorological Society Certification Practice Test