Observing snowmelt dynamics on fast ice in Kongsfjorden, Svalbard, with NOAA/AVHRR data and field measurements

Abstract

Temporal snowmelt dynamics on fast ice in Kongsfjorden/Svalbard are studied for the period 1990–2003, using visible and near-infrared channels of the Advanced Very High Resolution Radiometer (AVHRR). Long-term radiation data from an adjacent Baseline Surface Radiation Network station, as well as extensive glaciological and meteorological field measurements on the melting ice in 2002 and 2003, are used to validate a snowmelt index derived from the satellite data. This study shows that the remote sensing data are in good agreement with the field observations. However, the temporal variability of atmospheric water vapour has an impact on the snowmelt index, and must be accounted for through atmospheric correction. The analysis of long-term satellite data provides valuable insight into the strength and rate of the snowvolume decay, and reveals a strong interannual variability of the snowmelt intensity. However, a precise date for determining melt onset requires clear-sky AVHRR data throughout the onset period.