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Questions and Answers
What is the dry adiabatic lapse rate per 1000 ft?
What is the dry adiabatic lapse rate per 1000 ft?
If the surface temperature is 15°C, what is the temperature at 10000 ft in a current of ascending unsaturated air?
If the surface temperature is 15°C, what is the temperature at 10000 ft in a current of ascending unsaturated air?
What happens to a parcel of unsaturated air when lifted to just below the condensation level and then returned to its original level?
What happens to a parcel of unsaturated air when lifted to just below the condensation level and then returned to its original level?
When a parcel of moist but not saturated air rises adiabatically, which aspect changes?
When a parcel of moist but not saturated air rises adiabatically, which aspect changes?
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How can a sample of moist but unsaturated air become saturated?
How can a sample of moist but unsaturated air become saturated?
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What is the decrease in temperature per 100 metres for an unsaturated rising parcel of air?
What is the decrease in temperature per 100 metres for an unsaturated rising parcel of air?
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Why is the rate of cooling of ascending saturated air less than that of ascending unsaturated air?
Why is the rate of cooling of ascending saturated air less than that of ascending unsaturated air?
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What characterizes a layer that is absolutely unstable?
What characterizes a layer that is absolutely unstable?
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How is the height of the lifting condensation level primarily determined?
How is the height of the lifting condensation level primarily determined?
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What is the approximate temperature decrease in a saturated rising parcel of air at lower atmospheric levels?
What is the approximate temperature decrease in a saturated rising parcel of air at lower atmospheric levels?
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What type of atmospheric layer is indicated by a temperature decrease of 1oC per 100m?
What type of atmospheric layer is indicated by a temperature decrease of 1oC per 100m?
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If unsaturated surface air at 12oC rises to 6000 ft, what is the final temperature?
If unsaturated surface air at 12oC rises to 6000 ft, what is the final temperature?
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Which statement is true regarding an Environmental Lapse Rate (ELR) of 2.9oC per 1000 ft?
Which statement is true regarding an Environmental Lapse Rate (ELR) of 2.9oC per 1000 ft?
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What happens to the temperature of a saturated air mass as it descends down a slope?
What happens to the temperature of a saturated air mass as it descends down a slope?
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Which statement about the cooling rate of unsaturated and saturated parcels is correct?
Which statement about the cooling rate of unsaturated and saturated parcels is correct?
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What indicates increasing stability in a layer of air?
What indicates increasing stability in a layer of air?
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Which statement best describes a conditionally unstable layer?
Which statement best describes a conditionally unstable layer?
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What describes a layer where the temperature increases with height?
What describes a layer where the temperature increases with height?
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What happens to rising air in terms of temperature?
What happens to rising air in terms of temperature?
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What characterizes a layer with a temperature difference of 2°C over a height of 100m?
What characterizes a layer with a temperature difference of 2°C over a height of 100m?
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How does a moist but unsaturated parcel of air become saturated?
How does a moist but unsaturated parcel of air become saturated?
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What defines a layer of air where temperature remains constant with height?
What defines a layer of air where temperature remains constant with height?
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During an adiabatic process, how is heat behavior described?
During an adiabatic process, how is heat behavior described?
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Study Notes
Dry Adiabatic Lapse Rate
- The dry adiabatic lapse rate is 3.0°C per 1000 ft.
Temperature Changes with Elevation
- At a surface temperature of 15°C, the temperature at 10,000 ft in ascending unsaturated air is -15°C.
- When a parcel of unsaturated air is lifted and then returned to its original level, its temperature remains the same as the starting temperature.
Humidity Changes in Air Parcels
- In rising moist but unsaturated air, relative humidity changes as it rises.
- A moist but unsaturated air parcel becomes saturated by expanding it adiabatically.
Cooling Rates
- Unsaturated air decreases in temperature by 1°C per 100 m as it rises.
- The cooling rate of ascending saturated air is less than that of unsaturated air because heat is released during condensation.
Descending Air Masses
- A saturated air mass descending a slope will increase its temperature at a lower rate than dry air due to heat absorption from evaporation.
Stability of Air Layers
- The stability of a layer increases when warm air is in the upper part and cold air is in the lower part.
- A layer in which temperature increases with height is classified as absolutely stable.
Conditional Stability
- A layer is conditionally unstable if the environmental lapse rate is less than 1°C per 100 m.
Unstable Layers
- A layer that has a temperature decrease of more than 1°C per 100 m is considered absolutely unstable.
Inversions
- An inversion is identified as an absolutely stable layer, where temperature increases with height.
Adiabatic Processes
- During an adiabatic process, heat is neither added nor lost, resulting in cooling primarily due to expansion.
Cumulus Clouds and Condensation Levels
- The lifting condensation level is influenced by both temperature and dew point at the surface.
Temperature Decrease in Saturated Air
- The temperature decreases by approximately 0.6°C per 100 m in a saturated rising parcel of air.
Environmental Lapse Rate (ELR)
- The average environmental lapse rate is approximately 2.0°C per 1000 ft.
- An ELR of 2.9°C per 1000 ft indicates a conditionally unstable layer.
Final Temperature Calculations
- For unsaturated air at 12°C rising to 6000 ft, the final temperature is -6°C.
- A layer that decreases in temperature at 1°C per 100 m is considered neutral for dry air.
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Description
Test your understanding of adiabatic processes with this quiz. It includes questions on the dry adiabatic lapse rate, temperature changes with altitude, and behavior of unsaturated air. Perfect for aviation students and enthusiasts!
