Power station plumes in Czechia and Germany
25 December 2006 00:00 UTC
The image shows a NOAA 15 night-time RGB composite image (night microphysics). The black arrows point to plumes generated by power stations.
04 May 2023
24 December 2006
By Martin Setvak (CHMI)
See also: 18–19 December 2006, NOAA 17 image, source: M. Setvak.
The yellow pink colour (green in some of the linked images below) of the plumes results from different plume microphysics - smaller size of the droplets inside the plume. Smaller size means lower emissivity and thus lower brightness temperature in the AVHRR band 3b (IR3.7) as compared to the AVHRR bands 4 and 5 (see also images from 02:14 UTC, 04:24 UTC and 06:04 UTC, source: M. Setvak). In the black and white band 4 image there is no trace of these plumes, while band 3b image shows these as slightly brighter (colder).
In contrast, the 'plume' labelled with a yellow arrow has a natural origin. North winds induce a lee wave south of Krkonoše Mountains (at the Czech/Polish border), which generates small particles that are then carried downwind, to the south. Another lee wave phenomenon is labeled with a blue arrow. Here, the Jeseníky Mountains generate a ship-wave pattern within which the stratus clouds are dissolved, and at the same time several lee wave clouds are formed.
The animation of the 24-hour cloud microphysics RGB composite (24 Dec. 09:00 UTC–25 Dec. 15:00 UTC, source: M. Setvak) documents significant temporal variability of all of these phenomena. Also notice the ship-wave pattern south of the Tatra mountains (Slovak/Polish border), and the blocking effect of the Alps.
Additional content
Animation Met-8 24-hour Cloud Microphysics RGB, (24 Dec. 09:90 UTC–25 Dec. 15:00 UTC, source: M. Setvak)
