Comments on the Weather Assignment
This assignment is perhaps the most difficult of the course. In reading the first, brave,
few postings, I see that contributing a few “comments” might shed some light on the
subject, without giving away the answers. As you construct your responses, please
consider the following when answering the eight questions.
1. Why does a "parcel of air" cool as it rises? Warm as it descends?
a. Pressure;
b. Temperature;
c. Adiabatic cooling; adiabatic warming (the most important reason).
2. What can cause a cloud to appear? What can cause a cloud to disappear?
a. Appear: increase in quantity of moisture and/or decrease in temperature
b. Disappear: warming of cloud by sun; cloud dissipates its moisture by
raining/snowing;
c. Saturation;
d. Vapor pressure;
e. LCL or lifting condensation level.
3. What causes some clouds to ascend above a mountain, and others hover below
the mountain peak?
a. Buoyancy;
b. Stability.
4. What causes the temperature of a "parcel of air" to COOL at TWO different
rates while ascending a mountain, but WARM at only ONE rate while
descending a mountain?
a. ambient atmosphere lapse rate;
b. Dry Adiabatic Lapse Rate;
c. Wet Adiabatic Lapse Rate.
5. What causes some air parcels to be stable (not rising on their own accord), and
others unstable (rising on their own accord)?
a. Same as #3
6. What can cause a change in the actual humidity of a "parcel of air"?
a. Moisture;
b. Temperature.
7. What can cause a change in the capacity of a "parcel of air"?
a. Pressure (increase or decrease?);
b. Temperature (increase or decrease?).
8. How is "saturation of humidity" related to the production of rain, snow, sleet?
a. Once a parcel of air is saturated and cannot hold any more moisture, it
releases its moisture to the outside atmosphere, forms a cloud, which can
then release its moisture in the form of rain or snow (depending on the
temperature) when it becomes too heavy to hold.
This assignment is perhaps the most difficult of the course. In reading the first, brave,
few postings, I see that contributing a few “comments” might shed some light on the
subject, without giving away the answers. As you construct your responses, please
consider the following when answering the eight questions.
1.Why does a "parcel of air" cool as it rises? Warm as it descends?
a.Pressure;
b.Temperature;
c.Adiabatic cooling; adiabatic warming (the most important reason).
2.What can cause a cloud to appear? What can cause a cloud to disappear?
a.Appear: increase in quantity of moisture and/or decrease in temperature
b.Disappear: warming of cloud by sun; cloud dissipates its moisture by raining/snowing;
c.Saturation;
d.Vapor pressure;
e.LCL or lifting condensation level.
3.What causes some clouds to ascend above a mountain, and others hover below the
mountain peak?
a.Buoyancy;
b.Stability.
4.What causes the temperature of a "parcel of air" to COOL at TWO different rates while
ascending a mountain, but WARM at only ONE rate while descending a mountain?
a.ambient atmosphere lapse rate;
b.Dry Adiabatic Lapse Rate;
c.Wet Adiabatic Lapse Rate.
5.What causes some air parcels to be stable (not rising on their own accord), and others
unstable (rising on their own accord)?
a.Same answer as #3.
6.What can cause a change in the actual humidity of a "parcel of air"?
a.Moisture;
b.Temperature.
7.What can cause a change in the capacity of a "parcel of air"?
a.Pressure (increase or decrease?);
b.Temperature (increase or decrease?).
8.How is "saturation of humidity" related to the production of rain, snow, sleet?
a.Once a parcel of air is saturated and cannot hold any more moisture, it releases its
moisture to the outside atmosphere, forms a cloud, which can then release its moisture in
the form of rain or snow (depending on the temperature) when it becomes too heavy to
hold.