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Glaciers and climate change in Iceland:Mass balance and climate scenarios
Applications in the Himalaya
Helgi BjörnssonInstitute of Earth Sciences, Universtiy of Iceland
Dagfinnur Sveinbjörnsson
Öræfajökull
Mýrar
VatnajökullLangjökull Hofsjökull
MýrdalsjökullEyjafjallajökull
Glaciers cover 11% of IcelandThey are rapidly shrinking
Drangajökull
Snæfellsjökull
20 years of precipitation on Iceland
Firnline
Ablation area
Accumulation area
Ice flo
w
Runoff
Acquisition of basic data:Glacier geometry: surface and bedrock Glacier mass balance Ice dynamics Glacio-meteorology Drainage of meltwater
Modeling:Mass balanceIce dynamicsGlacier response to climate
Analysis of glacial evolution
1995-2007: 10 m 80 km3
accelerating volume loss
Mass balance
Approach:Field observations & modelling ⇒ prediction given climate scenarios
Glacier responseGlac
ier fl
ow m
odel
Climate scenario
Mass balance model
0.18 °C/decade
0.25 °C/decade
3.4 mm/decade.
Climate change scenario for Icelandic highland
Note:Volumes and areas are normalized to present day valuesSpecific runoff is from the present day glacier covered area
Predicted response to CE climate change scenario
Model responses shown for three Icelandic glaciers:Vatnajökull, Langjökull and Hofsjökull
Year: 1990
Year: 2000
Year: 2010
Year: 2020
Year: 2030
Year: 2040
Year: 2050
Year: 2060
Year: 2070
Year: 2080
Year: 2090
Year: 2100
Year: 2110
Year: 2120
Year: 2130
Year: 2140
Year: 2150
Year: 2160
Year: 2170
Year: 2180
Year: 2190
Consequences
• Glaciers disappear in 100-200 yrs
• Discharge from glaciers increases over next 50 yrs and then decreases
• Seasonal rythm in discharge changes, some rivers disappear
• River discharge = precipitation
• Changes in sediment load of rivers
SourcesSources ofof jjöökulhlaupskulhlaups
Research Program on Glacial Changes in the Himalaya and the Consequences for Economic and
Social Development
Proposal initiated by the President of IcelandHE Ólafur Ragnar Grímsson
Indus, Ganges, Brahmaputra
Research steps toward prediction
1. Collecting required basic field data
2. Develop glaciers models – mass balance– physical flow dynamics
3. Combine mass balance and flow models and run for different climate scenarios
4. Prediction, analyses of consequences and adaptation
• Requires education and training of young scientists ,-informed and constructive political reactions
Consequences of Himalayan glaciers disappearing in 40-70 years
• Hydrology– Flood hazards, outburst floods
– Seasonal changes in river discharge, drinking water, irrigation
– Drought
– Changing design criteria of bridges and hydropower plants
• Regional planning and development, adaptation, mitigation– Agriculture, food production
– Transport
– Tourism
• Impact on ecological systems, human health