Geoscience Reference
In-Depth Information
Table 5.1. Representative shortwave albedos and longwave emissivities relevant to the
climate system
Material
Shortwave albedo
Longwave emissivity
Water
a
0.08
0.95-1.00
Fresh
0.70-0.90
0.82
Snow
Old
0.45-0.60
0.89
Ice
0.35
0.98
Tundra
0.20
0.95-0.97
Desert
0.38
0.95-0.96
Tropical savanna
0.18
0.97-0.99
Grassland
0.10-0.20
0.97-0.99
Cropland
0.15-0.25
0.97-0.99
Tropical forest
0.08-0.13
1.00
Boreal forest
0.16
0.98
Wet sand
0.25
0.90
Dry sand
0.40
0.76
Soil
Wet soil
0.06-0.13
0.66
Dry soil
0.22-0.33
0.94
Cumulus
0.65-0.75
0.80
b
0.10
b
Clouds
Cirrus
0.45-0.60
0.99
b
Stratus
0.35-0.55
Asphalt
0.10
0.93
Manufactured
material
Concrete
0.40
0.96
Brick
0.30
0.93
a
Assumes that the sun is directly overhead.
b
Values are approximate because cloud emissivities vary greatly depending on the cloud's composition
(e.g., liquid water and ice content, droplet sizes) and wavelength.
(or contact with the surface) into the atmosphere across a unit area in 1 second.
Then, the sensible heat flux is
(5.11)
Hwc
p
=
ρ
.
S
(4) The
latent heat flux,
,
H
L
, is the rate at which heat is exchanged between the
atmosphere and the surface due to liquid-to-vapor (and vice versa) phase
