CH. 8 - WX Part 1 Flashcards
What causes pressure differences that result in different barometric or altimeter settings?
Unequal heating in different geographic areas.
What does the development of thermals depend upon?
Solar heating.
What defines the troposphere in terms of temperature?
A decrease in _____________ with an increase in _____________.
A decrease in temperature with an increase in altitude.
What is associated with the top of the troposphere?
An abrupt change in the _____________ _____________ _____________.
An abrupt change in the temperature lapse rate.
What atmospheric layer is the jet stream located near?
Near the boundary between the _____________ and _____________.
Near the boundary between the troposphere and stratosphere.
What weather phenomenon is commonly found on the colder side of a jet stream?
Clear air turbulence.
How does the jet stream change during winter in the middle latitudes?
It shifts toward the south and its speed increases.
What is a temperature inversion?
When temperature increases with altitude gains instead of decreasing.
What causes a sea breeze?
Land heating up faster than water, creating a low-pressure area over land.
How is moisture added to the air for cloud formation?
By _____________ and ______________ of surface water.
By evaporation and sublimation of surface water.
What happens as air temperature cools to its dew point?
The air becomes saturated, and condensation occurs.
How can you estimate the height above ground of cloud bases using surface temperature and dew point?
Subtract the _______________ _______________ from the _______________ temperature (in Fahrenheit), divide by _______________, and multiply by _______________.
Subtract the dew point from the surface temperature (in Fahrenheit), divide by 4.4, and multiply by 1,000.
How are clouds categorized according to their height?
Clouds are divided into four families based on their height ranges.
What determines the stability of an air mass?
The lapse rate of the temperature of the air.
What does a large lapse rate indicate about air stability?
It indicates instability.
What does a small lapse rate indicate about air stability?
It indicates stability.
What are the characteristics of stable air?
Stratiform clouds, poor visibility, and smooth air.
What are the characteristics of unstable air?
Cumuliform clouds, good visibility, and turbulence.
What causes winds to flow from high to low pressure areas?
Pressure gradient force.
How does the proximity or difference in pressure between areas affect wind force?
Closer areas or greater pressure differences result in _______________ wind force.
Closer areas or greater pressure differences result in stronger wind force.
How does the Earth’s rotation affect wind direction in the Northern Hemisphere?
Winds are curved to the _____________ due to the _____________ Force.
Winds are curved to the right due to the Coriolis Force.
Why are winds slowed near the surface?
Due to interference from terrain and obstructions, leading to surface friction.
How does surface friction affect the direction of winds near the surface?
It _______________ the _______________Force, causing winds to back (shift _______________) and slow down.
It weakens the Coriolis Force, causing winds to back (shift counterclockwise) and slow down.
What meteorological phenomenon occurs when a temperature inversion traps air?
Wind shear.
Under what conditions is wind shear most likely to occur?
During a _______________ inversion with surface winds of at least ____ knots.
During a temperature inversion with surface winds of at least 25 knots.
At what altitudes and from what directions can wind shear occur?
Wind shear can occur at all altitudes and from all directions.
