Temperature of the unsaturated air parcel

Question

Question 1:

If this air rises as unsaturated (dry) air from 1000 mb, determine its temperature at 500 mb by following the solid, straight green dry adiabatic lapse rate line passing through the starting point, up to 500 mb. At 500 mb, the temperature of the unsaturated air parcel is about ______ °C.

• -5
• -35
• -45

Question 2:

If this air rises as saturated air from 1000 mb, determine its temperature at 500 mb by following the dashed, curved blue saturated adiabatic lapse rate line passing through the starting point, up to 500 mb. At 500 mb, the saturated air parcel’s temperature is approximately ____ °C.

• -15
• -25
• -35

Question 3:

At 500 mb, the temperature of the unsaturated air parcel is ______________ the temperature of the saturated air parcel.

• lower than
• the same as
• higher than

Question 4:

This comparison demonstrates that rising unsaturated, clear air cools ______ than rising saturated, cloudy air over the same pressure change.

• more
• less

Question 5:

Begin once again with unsaturated air at 17 °C at 1000 mb. Because it is unsaturated, its relative humidity initially is ________ 100%.

• greater than
• equal to
• less than

Question 6:

As this air rises, assume it becomes saturated at 800 mb. Being unsaturated from 1000 mb to 800 mb, it will follow a ________ adiabatic lapse rate line.

• dry
• saturated

Question 7:

Becoming saturated at 800 mb, its relative humidity is now _____________ 100%.

• greater than
• equal to
• less than

Question 8:

As the air continues to rise, it will follow a ________ adiabatic lapse rate line.

• dry
• saturated

Question 9:

Continue the ascent to 500 mb. The air parcel temperature is now approximately ____ °C.

• -18
• -27
• -34

Question 10:

This temperature is ______________ the temperature achieved by the unsaturated parcel that ascended dry adiabatically the entire way to 500 mb in item 1.

• higher than
• equal to
• lower than

Question 11:

If condensation was occurring during the ascent from 800 mb to 500 mb, the air parcel would have ___________ water vapor during the ascent.

• gained
• lost
• had no change in

Question 12:

Throughout this saturated portion of the ascent, the relative humidity of the air parcel is ____________.

• greater than 100%
• 100%
• less than 100%

Question 13:

Assume that all the water that condensed (or deposited) during the ascent was immediately lost as precipitation from the parcel. Therefore, if the air parcel at 500 mb begins to descend, it will experience warming by compression and immediately become an unsaturated parcel. As the parcel sinks back to the 1000-mb level, it will warm at the dry adiabatic lapse rate, as shown by following the dry adiabatic lapse rate line down from the point at 500 mb.

When it arrives back at 1000 mb, its temperature is ___ °C.

• 17
• 27
• 37

Question 14:

This parcel’s final temperature is _______________ its beginning temperature when it was initially at 1000 mb.

• higher than
• the same as
• lower than

Question 15:

The relative humidity of this air parcel is now _____________________ what it was when it began its journey at 1000 mb.

• greater than
• equal to
• less than

Question 16:

The change from the initial parcel temperature to the final parcel temperature at the 1000-mb level was caused by condensation (or deposition) which _________ latent heat.

• releases
• absorbs

Question 17:

The Investigation 6A, Figure 2’s surface weather map for 00Z 14 OCT 2013 showed that Buffalo, NY ______ have overcast sky conditions at map time.

• did
• did not

Question 18:

Green Bay, WI was near the center of the high-pressure system that was dominating the weather in the upper Mid-West. Green Bay’s temperature was 50 °F (obscured) and dewpoint was 40 °F; the sky cover on the surface map was reported as _________________.

• clear
• partly cloudy
• mostly cloudy
• overcast

Question 19:

Based on the reported sky conditions, Buffalo had saturated atmospheric conditions above the ground and Green Bay ___________.

• did also
• did not

Question 20:

Recall that on Stüve diagrams, the bold irregular curve to the right is the temperature profile while the bold curve to the left is the dewpoint profile. Where the curves are superimposed, the temperatures and dewpoints are equal.

Buffalo’s Stüve diagram (Investigation 6A, Figure 2) showed by the separation of the temperature and dewpoint values at and near the surface that the surface air ________ saturated.

• was
• was not

Question 21:

Air, rising from the surface at Buffalo, would ______________.

• expand and cool
• be compressed and warm

Question 22:

The temperature profile from the surface up to about 970 mb over Buffalo was along the ________________ adiabatic lapse rate line printed on the diagram. This was evidence of surface air moving upward and cooling by

• expansion at the unsaturated adiabatic lapse rate.
• straight, solid, green dry
• curved, dashed, blue saturated

Question 23:

The air rising from near the surface above Buffalo cooled, and at about 970 mb, its temperature and dewpoint _________ become equal.

• did
• did not

Question 24:

The air over Buffalo at 970 mb __________ saturated.

• was
• was not

Question 25:

The lapse rate of unsaturated rising air in the atmosphere is theoretically 9.8 C° per km. This calculated lapse rate value in the actual atmosphere in this case was _______________ the unsaturated adiabatic lapse rate.

• Unsaturated rising air really does follow an adiabatic process!
• equal to
• several degrees different from

Question 26:

The temperature profile from 970 mb up to about 600 mb over Buffalo was approximately parallel to a nearby _______________ adiabatic lapse rate line printed on the diagram.

• straight, solid, green dry
• curved, dashed, blue saturated

Question 27:

The Buffalo rawinsonde text data also provided the following: 601 mb occurred at 4400 m with a temperature of –5.1 °C. The temperature difference between 970 and 601 mb over the altitude difference was therefore an equivalent 5.1 C° per kilometer. The average lapse rate of saturated rising air in the atmosphere is approximately 6 C° per km. This calculated lapse rate value is ____________ the average saturated adiabatic lapse rate.

• within a degree of
• five degrees from

Question 28:

The separation of the temperature and dewpoint profiles over Green Bay show that the air ______ saturated. Note the increase of temperature (an inversion) from the surface to about 995 mb over Green Bay. This was likely due to radiational cooling of the ground following sunset, which in turn, cooled the air immediately above the surface.

• was
• was not

Question 29:

Air, rising from above that inversion layer over Green Bay, would ____________.

• expand and cool
• be compressed and warm

Question 30:

The temperature profile from about 995 mb up to about 825 mb over Green Bay is nearly parallel to the _________________ adiabatic lapse rate line printed on the diagram.

• straight, solid, green dry
• curved, dashed, blue saturated

Question 31:

The 9.1 C°/km lapse rate value _________ within a degree of the theoretical 9.8 C° per kilometer value of the dry adiabatic lapse rate.

• was
• was not