Chapter 6
Which one of the following soundings indicates an atmosphere that is unstable for both cloudy and clear air parcels?
-12 Celsius degrees per 1000 m
An unsaturated (clear) air parcel at an initial temperature of 5 C is forced to ascend 2500 meters. Following ascent, the air parcel has a temperature of about
-20 C
Atmospheric stability can change with
-altitude -time -location Any of the above is correct.
Rain may
-infiltrate the soil -run off into rivers and lakes -evaporate Some combination of the above is correct.
As an unsaturated (clear) parcel of air ascends dry adiabatically,
-its relative humidity increases -its saturation vapor pressure decreases -its temperature drops (All of the above are correct.)
As unsaturated (clear) air flows down the leeward slopes of a mountain range,
-the air temperature rises -the relative humidity decreases -the saturation vapor pressure increases (All of the above are correct)
The vapor pressure is 18 mb and the saturation vapor pressure is 18 mb. What is the relative humidity?
100%
If the air temperature is 20 °C and the vapor pressure has the same value as the saturation vapor pressure, the relative humidity is
100%.
The mixing ratio is 10 g/kg and the relative humidity is 40%. What is the saturation mixing ratio?
25 g/kg
The vapor pressure is 3 mb and the saturation vapor pressure is 12 mb. What is the relative humidity?
25%
If the mixing ratio of a parcel of air is 2 grams per kilogram and its saturation mixing ratio is 6 grams per kilogram, the relative humidity is ______ percent.
33.3
In winter, the precipitable water is likely to have its highest value in ________.
Miami, FL
If a saturated (cloudy) air parcel is heated (say by absorption of radiation), its relative humidity ______.
decreases
If the temperature of an unsaturated (clear) air parcel does not change while its mixing ratio increases, the density of the parcel ______.
decreases
A relatively warm surface tends to ______ the overlying air.
destabilize
The saturation mixing ratio is _______ proportional to air temperature.
directly
The saturation vapor pressure is _______ proportional to air temperature.
directly
As the temperature of a saturated (cloudy) air parcel falls, its relative humidity ______.
does not change
Rising parcels of saturated (cloudy) air do not cool as rapidly as rising parcels of unsaturated (clear) air because
expansional cooling of saturated air is partially compensated for by release of latent heat that accompanies cloud formation
On a clear and calm day, the relative humidity usually ______ between sunrise and early afternoon.
falls
As unsaturated (clear) air ascends within the atmosphere, its temperature
falls at the dry adiabatic lapse rate.
The largest fresh water reservoir in the global hydrologic cycle:
ice sheets and glaciers
As the difference between the dewpoint and the ambient air temperature decreases, the relative humidity __________.
increases
Relative humidity is _______ proportional to air temperature.
inversely
On the continents over the course of a year, annual precipitation _______ annual evapotranspiration.
is greater than
As saturated (cloudy) air ascends within the atmosphere,
it expands and cools.
In the global water budget, annual precipitation is greater than annual evapotranspiration
on the continents.
The moist adiabatic lapse rate
ranges from about 4 Celsius degrees per 1000 m to almost 10 Celsius degrees per 1000 m.
In an inversion, air temperature _______ with increasing altitude.
rises
A temperature inversion indicates _______ atmospheric conditions.
stable
The relative humidity increases when the vapor pressure is constant and
the air cools.
The relative humidity increases when the temperature is constant and
the mixing ratio increases.
Conditional stability indicates that an air layer is
unstable for saturated and stable for unsaturated air parcels.
Cumulus clouds are more likely to form over
vegetated land surface in summer.
On a clear and calm day, the relative humidity has its lowest value
when air temperature is maximum.