(b) During the time when the strong west 
winds are most active there is little exposed 
sediment, so they move snow. When the north- 
east winds become more active the spring thaw 
exposes sediments in the dune area (east of T-1) 
and along the river channels. Also, the roads 
become sources of dust when they become 
snow-free during spring in direct proportion to 
the amount of traffic on them (see sequential 
photographs). 
Some comparisons of the amounts of dust 
on the east and west sides of major roads are 
presented in Table 8, which is based on the data 
of Table 5. The electrical conductance of the 
meltwater obtained from the samples is also 
tabulated in Table 8. The conductance values 
were either measured at 25°C, or corrected to 
25°C by the following relationship: 
Co5 = M, X 0.01 [1 + 0.025(25 — T)] 
where Cys is the conductance at 25°C, M, is the 
measured conductance at temperature T, and 
the conductivity cell constant is 0.01. 
It was not possible to determine the varia- 
tion of the temperature coefficient for the 
water, and precision of 10% was considered 
adequate, so the single temperature coefficient 
of 0.025 was used. This should “’. . . be satisfac- 
tory for all natural waters’’ (Smith 1962). 
In the center part of the Prudhoe Bay area, 
especially along the main NW trending road, 
there is generally a significantly higher dust 
content on the west side of the road than on the 
east side. These are the simplest cases to inter- 
pret because the roads are clearly the dominant 
sources of dust. The dust distribution indicates 
that the east winds move the most dust. As we 
move to the eastern part of the area, especially 
along the road between the Prudhoe Bay airfield 
and the dock, we note that the west/east ratio 
becomes less than unity. It does not mean that 
the west winds are more effective dust movers in 
this region. Instead, it indicates that the dune 
area to the east of the road contributes more 
dust than does the road. Indeed, the road must 
act as a partial barrier to westward movement of 
sediments from the dunes. This seems to be 
verified by the fact that the road itself acts as a 
source of sediments; yet, the dust moving west 
from it does not add enough material to equal 
that from the dunes on the east. In places where 
31 
the roads trend east-west, the difference in dust 
content between the two sides decreases. In 
these cases the distance south or north of the 
road is indicated together with a parenthetical 
indication of east and west components where 
they exist. 
The data on electrical conductance of melt- 
water follow the same general trend as do the 
dust content data. Occasionally, we find an 
abnormally high conductance value such as in 
sample 33 by the airport, which is the highest 
value of all. Another high value was obtained for 
sample 1 (not in Table 8), which is on the sea ice 
and most likely is contaminated by brine. 
Snow Melting 
In the dune area east of traverse T-1, we 
have observed beautiful marblelike mixtures of 
snow and sand in drifts during winter. Prior to 
melting these look like mixtures of different 
colored sand grains. By late April and the begin- 
ning of May, such features are rare because the 
snow begins to evaporate and to melt as solar 
radiation is absorbed by the darker sand grains. 
This process continues until patches of bare soil 
and vegetation are exposed. Water vapor is lost 
Pan ain = 
Fig. 14. Photo of hoarfrost crystals on snow. 
