CLOUDS
Which cloud type produces the **least** shortwave cloud cooling?
stratus (π = 60, CTP=800 hPa)
altostratus (π = 10, CTP= 560 hPa)
cirrostratus (π = 10, CTP = 180 hPa)
cirrus (π = 1, CTP= 180 hPa)
cirrus (π = 1, CTP= 180 hPa)
*TRUE* statement?
Aerosols are all solid
Aerosols are all liquid
Aerosols can be liquid or solid.
Aerosols can be liquid or solid.
Liquid cloud drops form in Earthβs atmosphere at
RH=95% or S=0.95
RH=101% or S=1.01
RH=110% or S=1.1
RH=400% or S=4
RH=101% or S=1.01
Global cloud cover of Earth measured by ISCCP?
10%
30%
66%
90%
66%
Integrating over which moment of the particle size distribution provides total surface area?
Zeroth (i.e., r^0)
First (i.e., r^1)
Second (i.e., r^2)
Third (i.e., r^3)
Third (i.e., r^3)
What is typical cloud drop radius?
0.1 nanometers
10 micrometers
1 centimeter
1 meter
10 micrometers
Largest aerosol?
ammonium sulfate
sulfuric acid
dust
soot
dust
Liquid cloud drop formation in Earthβs atmosphere occurs____
by homogenous nucleation
directly from the vapor phase
on pre-existing aerosol particles
only with water
on pre-existing aerosol particles
region with highest cloud cover measured by ISCCP?
Australia
Intertropical Convergence Zone
Colorado
Southern Ocean
Southern Ocean
If a cloud has an optical depth of 1, what fraction of the incident radiation passes through it?
2%
37%
90%
100%
37%
Which cloud type has a cloud top pressure less than 440 mb?
Cumulonimbus
Stratocumulus
Altostratus
Cumulus
Cumulonimbus
most important sink for atmospheric aerosols?
gas-to-particle conversion
scavenging by clouds
sea spray lofting sea salt
wind lofting dust particles
scavenging by clouds
Assume RH>100%. When the water vapor pressure increases,
the critical radius for a stable liquid cluster increases
the critical radius for a stable liquid cluster stays the same
the critical radius for a stable liquid cluster decreases
the critical radius for a stable liquid cluster decreases
maximum RH observed in the Earthβs atmosphere?
RH=99%
RH=101%
RH=110%
RH=400%
RH=101%
If the geometric thickness of an aerosol layer doubles but all else stays the same, the optical depth_____
doubles
stays the same
halves
doubles
For a fixed mass, adding what size cloud particles increases scattering of visible light the most?
small particles (cloud droplets)
medium particles (drizzle droplets)
large particles (rain droplets)
small particles (cloud droplets)
The formation of sulfate aerosol from oxidized sulfur dioxide and water is ___
Primary aerosol formation
Aerosol scavenging
Aerosol accumulation
Gas to particle conversion
Gas to particle conversion
*TRUE* about pure water when S=0.9 (RH=90%)?
liquid phase is thermodynamically stable
vapor phase is thermodynamically stable
both the liquid and the vapor phases are thermodynamically stable
neither the liquid nor the vapor phase is thermodynamically stable
vapor phase is thermodynamically stable
If you cannot see the disk of the sun β the optical depth is
Greater than 0.1
Greater than 1
Greater than 3
Greater than 3
Keeping all else the same - increasing the effective radius _____
increases the optical depth
does not affect the optical depth
decreases the optical depth
decreases the optical depth
Compared to clouds, aerosol layers typically have____
smaller particles
larger fall speeds
shorter atmospheric lifetimes
larger visible optical depths
smaller particles
If RH increases from 60% to 70%, the radius of a dry aerosol will _____
increase
stay the same
decrease
cannot answer based on information provided
cannot answer based on information provided
The Kelvin Equation quantifies that ____
saturation vapor pressure increases as drop size decreases.
saturation vapor pressure decreases as drop size decreases.
saturation vapor pressure increases as drop solute content decreases.
saturation vapor pressure decreases as drop solute content decreases.
saturation vapor pressure increases as drop size decreases.
If RH increases from 90% to 95%, wet aerosol radius ___
increases, decreasing visibility of Rockies
increases, increasing visibility of Rockies
decreases, decreasing visibility of Rockies
decreases, increasing visibility of Rockies
increases, decreasing visibility of Rockies
Doubling the optical thickness of an aerosol layer from 0.1 to 0.2 will____
increase vertical transmission of sunlight from 14% to 37%
increase vertical transmission of sunlight from 90% to 92%
decrease vertical transmission of sunlight from 90% to 82%
decrease vertical transmission of sunlight from 90% to 14%
decrease vertical transmission of sunlight from 90% to 82%