a. Old snow.
b. Hay.
c. Leaves.
d. Bark.
e. Sand.
f. Coal dust.
Figure 3. Surfaces on which the albedo measurements in Figure 4 were made (March 1994).
Due to the small area of these samples (about 45
Figure 5 shows that all of the pure materials,
cm2) we required an instrument with a much smaller
except snow*, are quite dark in the visible (400
footprint than a cosine collector used for albedo
700 nm). The sand has the highest reflectance of
measurements. Thus, for these samples we made
the materials at the 400550-nm wavelengths (blue
spectral reflectance measurements using an attach-
ment with a 1 field of view (the resulting footprint
*The spectral reflectance measurements shown in Fig-
was 0.75 cm2). These measurements were taken
ure 5 for are for fresh snow; consequently the reflec-
30 cm from the surface of the samples. The results
tance for this snow is higher than that of the old snow
of these measurements are shown in Figure 5.
shown in Figure 3.
4
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