Assessment of post-fire changes in land surface temperature and surface albedo, and their relation with fire/burn severity using multi-temporal MODIS imagery

This study evaluates the effects of the large 2007 Peloponnese (Greece) wildfires on changes in broadband surface albedo (a), daytime land surface temperature (LSTd) and night-time LST (LSTn) using a 2-year post-fire time series of Moderate Resolution Imaging Spectroradiometer satellite data. In addition, it assesses the potential of remotely sensed a and LST as indicators for fire–burn severity. Immediately after the fire event, mean a dropped up to 0.039 (standard deviation¼0.012) (P,0.001), mean LSTd increased up to 8.4 (3.0) K (P,0.001), and mean LSTn decreased up to -1.2 (1.5) K (P,0.001) for high-severity plots (P,0.001). After this initial alteration, fire-induced changes become clearly smaller and seasonality starts governing the a and LST time series. Compared with the fire-induced changes in a and LST, the post-fire NDVI drop was more persistent in time. This temporal constraint restricts the utility of remotely sensed a and LST as indicators for fire–burn severity. For the times when changes in a and LST were significant, the magnitude of changes was related to fire–burn severity, revealing the importance of vegetation as a regulator of land surface energy fluxes.