Jökull - 01.12.1971, Blaðsíða 8

ty/Day
Fig. 6. Climatological elements 1968.
6. mynd. Veðurþattir sumarið 1968.
ed mass balance terms, runoff, precipitation
and general meteorological and micrometeoro-
logical measurements during the summer
rnonths. The work had both a glaciological and
hydrological aspect. The glaciological problem
deals with the interrelationship between glacier
mass balance and the local climate on the
glacier and the general climate in the neigh-
bouring area. Continued measurements of
meteorological parameters on the glacier to-
gether with mass balance measurements might
give statistical relationships for constructing
quantitatively the past mass balance from ex-
isting observations from neighbouring mete-
orological stations. The answer depends on the
relative importance of local and advective
factors in shaping the glacier climate.
The hydrological problem deals with water
balance investigation for a glacierized drainage
area. The well known problem of inaccurate
precipitation point measurements rnakes it im-
possible to use existing runoff data to construct
accurate rnass balance values. The precipita-
tion term could on the other side be eliminat-
ed from the water balance if changes in the
glacier storage and runoff are known. For this
purpose Bægisárjökull which has a well defin-
ed drainage area is a good experimental basin.
The energy budget studies and models of
daily runoff fronr the glacier are discussed by
Björnsson (1972). The most important result
is presumably that for the period from July
to mid-August 1968 the radiation was respon-
sible for 55%, sensible heat 30% and latent
heat 15% of the ablation.
GENERAL METEOROLOGY
AT BÆGISÁRJÖKULL
General meteorological observations were
carried out on the glacier during the summer
seasons of 1967 and 1968. A description of the
observation procedure is given by Björnsson
(1972). An overall description of the data for
the observation periods is given in Fig. 5 ancl
Fig. 6. The meteorological observations define
the weather in the ablation seasons and illu-
strate the relative importance of advective
climatic factors and locally generated climate
on the glacier.
6 JÖKULL 21. ÁR