Jökull - 01.10.1998, Page 58

Tungnaárjökull 1994 Köldukvíslarjökull 1992*
1994* 1995»
Dyngjujökull 1992» 1993» 1 "i$95 • Brúarjökull 199^ 1994*
1995*
1000 1 200 1400 1000 1200 1400
ELA (m a.s.l.) ELA (m a.s.l.)
Fig. 20. Mean net mass balance as a function of the equilib-
rium line altitude on various outlets of Vatnajökull, 1991-
1995; Specific mass balance in m water equivalent, bw: win-
ter balance, bs: summer balance, bn: annual net balance.
- MeSalafkoma á nokkrum skriðjöklum Vatnajökuls, 1991-
1995. bw: vertarafkoma, bs: sumarafkoma, bn: ársafkoma.
than 1993 which had prolonged northerly winds. Other
summers were closer to average. Spatial variations in
the precipitation during the same year, also appear in
the data. A decrease in rain westwards along the north-
em part of Vatnajökull explains that during the summer
of 1993 glacial meltwater was only 45% of the mnoff
of Jökulsá á Brú (80% in other years) but 84% for
Jökulsá á Fjöllum.
Fig. 21. Accumulation area ratio for various outlets of Vatna-
jökull, 1991-1995.
- Ákomusvœði á nokkrum skriðjöklum Vatnajökuls sem
hlutfall af heildarflatarmáli þeirra, 1991-1995.
ACKNOWLEDGEMENTS
This paper is a report of work carried out in col-
laboration between the National Power Company and
the Science Institute, University of Iceland. Support
from the Research Fund of the University of Iceland
is acknowledged. Some of the data were collected
during expeditions of the Iceland Glaciological Soci-
ety. The manuscript was written during a sabbatical
leave of HB in 1996 at INSTAAR, Boulder, Colorado,
USA. We are indebted to Tómas Jóhannesson for con-
structive comments on the manuscript.
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JÖKULL, No. 45, 1998