Exam 3 Flashcards
(57 cards)
What initiates winds in the atmosphere?
B) Pressure gradients
True or False: The pressure gradient force acts from low pressure to high pressure.
False
Explain how temperature differences can lead to the formation of winds.
Temperature differences cause variations in air density, leading to pressure gradients. Air moves from high-pressure areas (cooler, denser air) to low-pressure areas (warmer, less dense air), resulting in wind.
What is the primary cause of general circulation in the atmosphere?
B) Temperature differences
Describe the role of the pressure gradient force in wind formation.
The pressure gradient force is the net force that drives air from areas of high pressure to areas of low pressure, initiating wind flow.
The two primary forces that influence wind direction are the______________ and the _________________?
Pressure Gradient Force (PGF), Coriolis Force (CF)
In which hemisphere does the Coriolis force defect moving objects to the left?
B) Southern Hemisphere
Describe how friction affects wind speed in the planetary boundary layer.
Friction slows down wind speed in the planetary boundary layer, reducing the influence of the Coriolis force and causing winds to cross isobars.
True or False: The Coriolis force is a real force that acts on moving objects.
False (It is an apparent force due to Earth’s rotation.)
Which of the following factors does NOT influence the strength of the Coriolis force?
D) Humidity levels
In the free atmosphere, geostrophic winds blow:
B) Parallel to isobars
True or False: Winds in the boundary layer are significantly influenced by friction.
True
What is the relationship between isobars and wind direction in the Northern Hemisphere?
Winds blow counterclockwise around low-pressure systems and clockwise around high-pressure systems, with the wind direction being influenced by the spacing of isobars.
What happens to wind speed as the pressure gradient increases?
C) Wind speed increases
Explain the concept of geostrophic balance.
Geostrophic balance occurs when the pressure gradient force and the Coriolis force are equal and opposite, resulting in winds that flow parallel to isobars.
Jet streams are typically found at what altitude?
C) 10-15 km
What causes the formation of jet streams in the atmosphere?
Jet streams form due to rapid changes in temperature and pressure in a relatively narrow region, creating steep pressure gradients that intensify wind speeds.
Which of the following is NOT a characteristic of jet streams?
C) They occur only in the tropics.
Describe the role of the Intertropical Convergence Zone (ITCZ) in global circulation.
The ITCZ is the area where the trade winds from the Northern and Southern Hemispheres converge, leading to rising air, cloud formation, and precipitation, significantly influencing tropical weather patterns.
What is the warming phase of the El Niño-Southern Oscillation called?
B) El Niño
True or False: La Niña conditions are characterized by warmer sea surface temperatures in the eastern Pacific.
False (La Niña is characterized by cooler sea surface temperatures.)
Describe the impact of El Niño on global weather patterns.
El Niño can lead to increased rainfall in the eastern Pacific, droughts in the western Pacific, and can disrupt normal weather patterns globally, affecting agriculture, fisheries, and climate.
If a hurricane is passing over a region, what would you expect the surface pressure to be?
The surface pressure would be low, as hurricanes are characterized by low-pressure centers that draw in surrounding air, leading to strong winds and storm conditions.
Which of the following statements is true regarding the Coriolis force?
A) It increases with latitude.
