Large dust cloud over the Canary Islands
12 January 2015 11:30 UTC
Photo credit: Munimara
Around the 12 January, a high layer of dust moved from north-western Africa covering the area around the Canary Islands, impacting visibility.
21 September 2022
12 January 2015
In the imagery on Figure 1, due to the high thermal contrast between the dust at high level and the surface, the pink signal is dramatic in the infrared colour composite.
The tenuous reflection in the solar image suggests a thin layer of dust, seen as hazy air.
However, it affects the retrieval of atmospheric motion vectors — sparse in that area due to the homogeneous layer.
Image comparison
Figure 1: Comparison of the Dust and Natural Colour RGBs. Dust is pink on the Dust RGB and looks more like a beige cloud on the Natural Colour RGB.
Figure 2 shows the difference between the channels at 10.8 and 12.0 µm. It corresponds roughly to the pink coloration usually interpreted as dust, and provides additional information on the areas with more dust.
In Figures 3 and 4 the orographic effect of the island mountains is visible in the dust cover, especially south west of the Canaries. Also, a long cumulus line can be seen, under the veil downstream of La Gomera (third island from left), as a vortex trail.
