Voyager imaging observations of Triton have been used to investigate t
he characteristics of the atmospheric hazes on Triton at three wavelen
gths: violet (0.41 mum), blue (0.48 mum), and green (0.56 mum). The gl
obally averaged optical depth is wavelength dependent, varying from 0.
034 in green to 0.063 in violet. These photometric results are dominat
ed by the properties of localized discrete clouds rather than by those
of the thinner, more widespread haze known to occur on Triton. The cl
oud particles are bright, with single-scattering albedos near unity at
all three wavelengths, suggestive of a transparent icy condensate. Th
e asymmetry parameter ( + 0. 6) and the wavelength dependence of the o
ptical depth both indicate cloud particles 0.2-0.4 mum in radius. The
clouds are concentrated at 50-60-degrees-S latitude, where opacities u
p to three times the global average are observed. This is the same lat
itude region where most of the evidence for current surface activity i
s found, suggesting that the clouds may be related to the plumes or at
least to some process connected with the sublimation of the south pol
ar cap. The effects of possible temporal variations in the haze opacit
y are examined. Increases in the haze opacity tend to redden Triton. H
owever, the degree of reddening is not sufficient to explain the full
range of observed changes in Triton over the past decade; variations i
n the surface properties appear to be necessary. (C) 1994 Academic Pre
ss, Inc.