ATS 350 Exam 3 Questions Answered Correctly Latest Version 2025-2026
What are the major forces that generate atmospheric circulations? - Answers 1. pressure
gradient force
2. coriolis force
3. friction
Why does the pressure gradient force exist? - Answers To restore equilibrium, always directed
from high to low pressure
Why does the coriolis force exist? - Answers 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? - Answers 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? -
Answers 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.
How would you draw the wind forces for a high pressure system in the northern hemisphere? -
Answers 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? -
Answers 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? -
Answers 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? - Answers
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? - Answers 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? - Answers 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? - Answers anemometer and wind vanes
What causes a sea breeze? - Answers 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? - Answers A sea breeze typically occurs during the
afternoon.
What causes a land breeze? - Answers A land breeze is caused by the land cooling more than
the ocean, leading to high pressure over the land and low pressure over the sea.
When does a land breeze typically occur? - Answers A land breeze typically occurs during the
night.
What weather conditions favor the formation of a land breeze? - Answers A land breeze
particularly happens under clear skies with radiative cooling.
How do pressure differences drive circulation? - Answers 1. Initially no horizontal temperature
gradients, so everything is constant pressure.
2. Heat the left side and cool the right
3. The left side expands and the right side contracts.
4. This generates higher pressure aloft than on the right.
5. A PGF aloft drives air from high to low (left to right)
6. Movement of the left column lowers the surface pressure on the left
7. Surface pressure is raised on the right side due to movement into this column
8. A PGF near the surface drives air from high to low (right to left)
9. This results in a large scale circulation cell with rising air in the warm column and sinking in
the cold.
What is a monsoon? - Answers A monsoon is a regional circulation system characterized by
seasonal changes in wind speed or direction.
How do ocean and land temperatures vary in a monsoon? - Answers Ocean temperatures don't
vary much, but land temperatures do.
What happens to pressure over land during the summer in a monsoon? - Answers Warmer
What are the major forces that generate atmospheric circulations? - Answers 1. pressure
gradient force
2. coriolis force
3. friction
Why does the pressure gradient force exist? - Answers To restore equilibrium, always directed
from high to low pressure
Why does the coriolis force exist? - Answers 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? - Answers 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? -
Answers 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.
How would you draw the wind forces for a high pressure system in the northern hemisphere? -
Answers 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? -
Answers 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? -
Answers 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? - Answers
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? - Answers 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? - Answers 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? - Answers anemometer and wind vanes
What causes a sea breeze? - Answers 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? - Answers A sea breeze typically occurs during the
afternoon.
What causes a land breeze? - Answers A land breeze is caused by the land cooling more than
the ocean, leading to high pressure over the land and low pressure over the sea.
When does a land breeze typically occur? - Answers A land breeze typically occurs during the
night.
What weather conditions favor the formation of a land breeze? - Answers A land breeze
particularly happens under clear skies with radiative cooling.
How do pressure differences drive circulation? - Answers 1. Initially no horizontal temperature
gradients, so everything is constant pressure.
2. Heat the left side and cool the right
3. The left side expands and the right side contracts.
4. This generates higher pressure aloft than on the right.
5. A PGF aloft drives air from high to low (left to right)
6. Movement of the left column lowers the surface pressure on the left
7. Surface pressure is raised on the right side due to movement into this column
8. A PGF near the surface drives air from high to low (right to left)
9. This results in a large scale circulation cell with rising air in the warm column and sinking in
the cold.
What is a monsoon? - Answers A monsoon is a regional circulation system characterized by
seasonal changes in wind speed or direction.
How do ocean and land temperatures vary in a monsoon? - Answers Ocean temperatures don't
vary much, but land temperatures do.
What happens to pressure over land during the summer in a monsoon? - Answers Warmer
