ATS 350 EXAM 3 EXAM QUESTIONS
WITH 100% CORRECT ANSWERS |
LATEST VERSION 2025/2026.
What are the major forces that generate atmospheric circulations? - ANS 1. pressure
gradient force
2. coriolis force
3. friction
Why does the pressure gradient force exist? - ANS To restore equilibrium, always directed
from high to low pressure
Why does the coriolis force exist? - ANS Because of earth's rotation. It is always perpindicular
to the wind, it increases as the wind speed increases, it changes the wind direction and not
speed, it is largest at the poles, it is zero at the equator, and it is to the right in the northern
hemisphere
Why does friction exist? - ANS It exists close to the surface because the surface isn't smooth.
It is the opposite direction of the wind and slows the wind down.
How would you draw the wind forces for a low pressure system in the northern hemisphere? -
ANS The wind direction is counter clockwise. The pressure gradient force is toward the
middle. The coriolis force is to the outside. The friction is opposite direction of the wind if close
to the surface.
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, How would you draw the wind forces for a high pressure system in the northern hemisphere? -
ANS The wind direction is clockwise. The pressure gradient force is toward the outside. The
coriolis force is to the middle. The friction is opposite direction of the wind if close to the
surface.
How would you draw the wind forces for a plot of straight isobars in the northern hemisphere?
- ANS The wind direction is curved. The pressure gradient force is toward the lowest
pressure. The coriolis force is the opposite direction. The friction is opposite direction of the
wind if close to the surface.
How does the spacing of isobars or lines of constant height determine the wind speed? -
ANS The closer the isobars, the faster the wind. If the isobars are closer there is a sharper
gradient in pressure. So the PGF is stronger, increasing wind speed
How does temperature determine the height of constant pressure surfaces aloft? -
ANS Warm air aloft expands the atmosphere, making the 500 mb pressure surface higher.
I.e. hotter air is less dense, so you have to go higher to achieve the same pressure.
How does temperature determine the pressure on constant height surfaces? - ANS At higher
temperatures, the pressure is lower because it is less dense.
As the height of constant pressure surfaces rise and fall horizontally, how does this correspond
to horizontal variations in pressure? - ANS Low height are troughs that correspond to low
pressure. High height are called ridges and correspond to high pressure
What devices measure wind speed and direction? - ANS anemometer and wind vanes
What causes a sea breeze? - ANS A sea breeze is caused by the land warming up more than
the ocean, leading to low pressure over the land and high pressure over the sea.
When does a sea breeze typically occur? - ANS A sea breeze typically occurs during the
afternoon.
2 | Page @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
WITH 100% CORRECT ANSWERS |
LATEST VERSION 2025/2026.
What are the major forces that generate atmospheric circulations? - ANS 1. pressure
gradient force
2. coriolis force
3. friction
Why does the pressure gradient force exist? - ANS To restore equilibrium, always directed
from high to low pressure
Why does the coriolis force exist? - ANS Because of earth's rotation. It is always perpindicular
to the wind, it increases as the wind speed increases, it changes the wind direction and not
speed, it is largest at the poles, it is zero at the equator, and it is to the right in the northern
hemisphere
Why does friction exist? - ANS It exists close to the surface because the surface isn't smooth.
It is the opposite direction of the wind and slows the wind down.
How would you draw the wind forces for a low pressure system in the northern hemisphere? -
ANS The wind direction is counter clockwise. The pressure gradient force is toward the
middle. The coriolis force is to the outside. The friction is opposite direction of the wind if close
to the surface.
1 | Page @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, How would you draw the wind forces for a high pressure system in the northern hemisphere? -
ANS The wind direction is clockwise. The pressure gradient force is toward the outside. The
coriolis force is to the middle. The friction is opposite direction of the wind if close to the
surface.
How would you draw the wind forces for a plot of straight isobars in the northern hemisphere?
- ANS The wind direction is curved. The pressure gradient force is toward the lowest
pressure. The coriolis force is the opposite direction. The friction is opposite direction of the
wind if close to the surface.
How does the spacing of isobars or lines of constant height determine the wind speed? -
ANS The closer the isobars, the faster the wind. If the isobars are closer there is a sharper
gradient in pressure. So the PGF is stronger, increasing wind speed
How does temperature determine the height of constant pressure surfaces aloft? -
ANS Warm air aloft expands the atmosphere, making the 500 mb pressure surface higher.
I.e. hotter air is less dense, so you have to go higher to achieve the same pressure.
How does temperature determine the pressure on constant height surfaces? - ANS At higher
temperatures, the pressure is lower because it is less dense.
As the height of constant pressure surfaces rise and fall horizontally, how does this correspond
to horizontal variations in pressure? - ANS Low height are troughs that correspond to low
pressure. High height are called ridges and correspond to high pressure
What devices measure wind speed and direction? - ANS anemometer and wind vanes
What causes a sea breeze? - ANS A sea breeze is caused by the land warming up more than
the ocean, leading to low pressure over the land and high pressure over the sea.
When does a sea breeze typically occur? - ANS A sea breeze typically occurs during the
afternoon.
2 | Page @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
