Sequential Photographs: Set No. 5. 
BP Storage Yard area during breakup 1972 
a. 24 May 
b. 5 June Arrow located at west end of 
(0%, 9 June storage pad and pointing east. 
d. 11 June 
Some brief comments on these sets of 
photographs are in order: 
Set Number 1: 
1a. The gravel haul road on the left and the 
main road which runs east-west had heavy traf- 
fic, so they were dusty, and dust spread over the 
adjacent snow. The north-south trending road 
by the arrow had no traffic and, consequently, 
no dust. 
1c and 1d. The effect of road orientation 
relative to wind is especially clear. The N-S road 
has the largest drifts, and they are larger on the 
east than on the west sides, as is consistent with 
the data from traverses T-5 and T-8 (see Tables 6 
and 7). 
Set Number 2: 
2a. The effect of a heavily traveled road on 
producing early. snowmelt is very clear in this 
photograph. 
2b. The snow is nearly gone from around the 
heavily traveled road, but large drifts remain 
adjacent to the N-S road to left of center. 
2c and 2d. Ponds of water are visible on the 
east side of the main road to right of center. 
This ponding is produced by the road and will 
contribute to its destruction. It results from the 
buildup of large drifts adjacent to the road, and 
the rapid melting of these drifts because of the 
dust deposited on them by heavy traffic. 
Set Number 3: 
3a. The dust from heavily traveled roads is 
producing melt adjacent to the roads before the 
clean snow on the tundra has begun to melt. 
This contributes to the formation of ice masses 
in and at the base of the snow near the roads 
(see text). 
3c. The larger amount of snow drifting is 
clearly on the east side of the roads. This 
indicates more effective transport of snow by 
the west winds. The location is midway between 
S35 
traverses 5 and 8, both of which showed this 
asymmetrical distribution of drifted snow (see 
Tables 6 and 7 and Fig. 13). 
Set Number 4: 
4a and 4b. The larger snow drifting on the 
east side combined with the larger dust drifting 
on the west side of the roads is apparent, 
especially in 4b. 
4c. A minimum of snow quantity about 
100 m from the roads appears to exist in some 
places. This phenomenon is well displayed along 
the roads by the arrow, especially to the left of 
the arrow. 
4d, e, and f. Note the dry lake near the 
arrowhead in 4d on 13 June; it was full of water 
on 15 June (photo 4e), but dry again on 30 June 
(photo 4f). 
Set Number 5: 
This set of photographs shows the over- 
whelming effect of dust from the Sagavanirktok 
River channel in ablating snow. In 5b and 5c the 
most effective snow drifting is on the east sides 
of the roads—from west winds. On the other 
hand, the dust is moving west—from east winds. 
Radiation Climate and Snow Breakup 
The main objective of this section is to 
present radiation measurements made at Prud- 
hoe Bay from early spring throughout the sum- 
mer seasons of 1972 and 1973 and relate these 
data to the melting of snow cover in these areas. 
The observations are relatively simple compared 
with the complex, full energy budget measure- 
ments reported elsewhere (Weller et al. 1974). 
The intention is to demonstrate to what extent 
such data can be used to explain physical 
processes at the tundra surface. The melting of 
the snow cover is of particular interest in this 
context since it probably represents the single 
most dynamic microclimatic event on the 
tundra. 
The outgoing and incoming long-wave and 
short-wave radiations were measured by Eppley 
precision pyrgeometers and pyranometers, 
respectively—two of each at Prudhoe Bay in 
1972. The radiation equipment used at Prudhoe 
Bay in 1973 was the same as in 1972, except 
that the reflected short-wave radiation was 
