These images are monitoring for the presence of volcanic ash emission in the vicinity of Iceland using infrared data from the Meteosat Second Generation (MSG) satellite. Because cloud particles and volcanic ash particles interact with the infrared radiation in different ways, data at several different wavelengths can be combined to identify the main ash plume, which, when present, would be shown as yellow and orange colours in the images. Note that it is only the thicker parts of the plume that are able to be detected by this method. In addition, the ash plume is often masked by overlying high cloud.