Wildfires were raging in California this summer. Let's see if we can spot some of them in Sentinel-2A images with the new Sentinel-Playground by Sinergise. The combination of the SWIR and NIR bands of Sentinel-2 or Landsat enables to produce accurate maps of burnt areas. The SWIR band is sensitive to the water content in the soil and vegetation, while the NIR band is sensitive to the vegetation health (photosynthetic activity). In addition, the radiance measured by a spaceborne sensor in the SWIR wavelengths increases if the surface is very hot (as taught us Prof. Planck in Hawaïï). As a result, a simple color composite of bands SWIR/NIR/Red gives a stunning view of burnt areas and can highlight ongoing fire areas if the smoke is not too opaque. In Coalinga, the Mineral Fire burnt nearly 3000 ha close to the city of Coalinga.
