Jökull - 01.12.1971, Page 3

JOKULL
Á R S R I T
JÖKLARAN NSÓKNAFÉLAGS ÍSLANDS
21. ÁR REYKJAVÍK 1971
Bægisárjökull, North-Iceland
Results of glaciological investigations 1967—1968
Part I. Mass balance and general meteorology
HELGI BJÖRNSSON,
CC!ENCE INSTITUTE, UNIVERSITY OF ICELAND
ABSTRACT
General meteorological invesligations to-
gether with mass balance measurements were
carried out on Bcegisárjökull (1.7 km2) in north-
ern Iceland during two glaciological years
(1966—67—68). The specific winter balance for
the first year was 1.55 m and 1.95 m for the
seconcl. The net balance was posilive (0.25 m)
in the first year but approximately zero for
the second year. A comparison between the
glaciological and hydrological method of rnass
balance measurements for 36 days midsummer
in 1968 showed that the precipitation was
underestimated although is was measured with
10 rain gauges in the drainage basin. The
hydrological method would have given a 35
percent higher value for the net balance than
tlie glaciological rnethod. About 70 percent of
the glacier runoff arose from the glacier melt.
Locally generated climate on the glacier was
proved to be negligible compared with advec-
tive factors in determining the glacier climate.
Continued measurements on the glacier com-
bined with mesometeorological studies might
therefore give interrelationships between cli-
matological elements which could be used to
reconstruct past mass balance variations. At
present time climatological values from the
nearest meteorological station at Akureyri must
be used directly as an indicator of past mass
balance together icith data from the glacier
for the two years considered. It appears thal
if the trend of cooler summer continues only
normal winter precipitation would be necess-
ary to give posilive net balance. The small
glaciers in northern Iceland would then give
a,n excellent opportunity to study the glacier
response to the positive mass balance.
INTRODUCTION
During the years 1967—1968 a study in
glacial-hydrology, micrometeorology and geo-
morpology was carried out on Bægisárjökull in
northern Iceland. The geomorphological in-
JÖKULL 21. ÁR 1