Jökull - 01.12.1971, Page 14

TABLE 3.
Fog and precipitation statistics, Bægisárjökull.
Period Number of days with Amounts of snowfall and rainfall, mm
Precipita- tion Snowfall Trace Fog Precipitation, mm Snow- fall Rain- fall Totals
O A\ o C\i /II o LO /11 o ö 7\ O Ö CM /II
1967
Juiy 18 2 4 13 12 11 6 2 2 ^201 78.1 98.11
August 1—18 .... 9 0 2 2 7 4 3 0 0 0 22.6 22.6
1968
Juiy 22 2 10 7 11 9 6 4 1 ^41 75.6 ^ 79.6i
August 1—9 5 0 3 0 1 1 0 0 0 0 3.3 3.3
1) Uncertain value.
of all days had daily mean in this interval.
The second mode between 7 to 8 °C reflects
temperatures in the warm period with souther-
ly winds from July 12 to 15. The histogram
for the whole observation period in 1968 has
1967 1968
í 1967 1968
Fig. 8. Histograms of relative frequency for
rnean daily air temperature at 2 m height.
8. mynd. Tíðni dagsmeðalhitastigs.
1 2 JÖKULL 21. ÁR
the same main form as that for July but it is
modified to some degree by the continued
warming in August which was accompanied by
southerly winds.
The histogram for July in 1968 has a small
main mode between 6 to 7 °C and shows a
more equal distribution and higher tempera-
tures than the histogram for July in 1967.
Loccjly generated climate
The characteristic negative skew of the histo-
grams in Fig. 8 illustrates the cooling effect
of the melting glacier. All curves have a main
mode about 1.5 °C above the arithmetic mean.
The influence of this local effect on the wind
system was investigated. Wincl roses like those
given in Table 2 were workecl out for night
ancl day time. The only significant difference
in the pattern of these wind roses was that
winds downhill the glacier were slightly more
frequent during the night than day time. This
Fig. 9. Wind-roses based on mean hourly ob-
servations at 2 m height.
9. mynd. Vindrósir úr meðalgildum klukku-
stunda.