Plume Plotter is showing minute-to-minute details of air pollution caused by Drax, taking account of local weather conditions.
See here for full details. And see here for a 2016 animation of Drax’s plume.
The Plume Plotter is built using one of the most widely used and respected air pollution modelling systems developed in the United States, to take into account the real terrain in the vicinity of the incinerator, current weather conditions and upper air data. The Drax page uses recent data which Biofuelwatch obtained from the Environment Agency. Plume Plotter’s assumptions are conservative, which means that actual pollution levels could be higher
Please note that Plume Plotter shows the plume from power stations and incinerators and temporary local increases in air pollution resultant from it. This is different from the emissions coming out of a smokestack which are relatively constant (unless plants or units are switched off). Often, plumes do not reach ground level in the dark, and sometimes none can be seen during the day because of weather conditions. It is worth keeping in mind that a lot of the pollution from power stations travels long distance and thus affects people over large areas.