摘要：The temporal variability of surface snow and glacier melt flux and runoff are investigated for the ablation area of Jakobshavn Isbræ, West Greenland. High-resolution meteorological observations both on and outside the Greenland ice sheet were used as model input. SnowModel, a physically based spatially distributed meteorological and snow evolution modeling system, is used to simulate the temporal variability of Jakobshavn Isbræ accumulation and ablation processes for 2000/01–2006/07. Winter snow depth observations and MODIS satellite-derived summer melt observations are used for model validation of accumulation and ablation. The modeled interannual runoff variability varied from 1.81 × 10 9 m 3 (2001/02) to 5.21 × 10 9 m 3 (2004/05), yielding a cumulative runoff at the Jakobshavn Glacier terminus of ∼2.25 to ∼4.5 m w.e. The average modeled Jakobshavn runoff of ∼3.4 km 3 a −1 was merged with previous estimates of Jakobshavn ice discharge to quantify the freshwater flux to Illulissat Icefjord. For both runoff and ice discharge the average trends are similar, indicating increasing (insignificant) influx of fresh water to Ilulissat Icefjord for the period 2000/01–2006/07. This study suggests that surface runoff forms a minor part of the overall Jakobshavn freshwater flux to the fjord: about 7% (∼3.4 km 3 a −1 ) of the average annual freshwater flux of ∼51.0 km 3 a −1 originates from the surface runoff.
