Large wildfire in Iceland in 2006: Size and intensity estimates from satellite data

Abstract

The largest recorded wildfire in Iceland's history raged in the sedges and shrubs of a wetland area in western Iceland from 30 March to 1 April 2006. The area affected by the fire was 73 km², as measured by mapping on the ground and satellite data, which is a very extensive fire for Nordic countries. Meteorological data from the area show that no rain had fallen there in 10 days prior to the fire, and that strong northerly winds persisted for that time. In the first 4 hours of the fire it travelled at a speed of ∼1 m s⁻¹ and the wind speed at the time was between 10 and 12 m s⁻¹. Data from the Moderate-resolution Imaging Spectroradiometer (MODIS) sensors onboard the Terra and Aqua satellites indicate that the radiative power of the fire during the first day reached a maximum of ∼250 MW for fire pixels flagged by the MODVOLC system, and ∼180 MW for pixels flagged by the MOD14/MYD14 product, although the temporal coverage of the satellites is limited to only two passes a day. The spatial and temporal pattern of the fire progression observed from satellites is consistent with ground observations. Measurements of the biomass in the area that burned and adjacent areas, and estimates from the fire radiative energy, indicate that 11 500 tonnes of dry biomass were consumed in the fire. Recent reduction in livestock grazing and climate warming may have attributed to the severity of the fire.

Acknowledgements

The authors would like to thank Anette Meier for her help with the figures. This work was supported by the Icelandic Ministry of Environment, and Sparisjódur Mýrasýslu (Throstur). Helpful advise and data from our collaborators in the Mýraelda-group is also graciously acknowledged.