Third Input: Another Difference Image

2 images differenced to create an input to a dust RGB [10.8 - 8.7]

For our third input to the RGB, we'll use another brightness temperature difference, 10.8 µm IR minus 8.7 µm IR channels.

Depiction of land with a dust layer vs. cirrus cloud above and arrows depicting absorption differences between the 10.8 vs. 8.7 micrometer channels

Both ice clouds and dust have negative brightness temperature differences in the 10.8 µm IR minus 8.7 µm IR channel difference, making it hard to tell them apart on the resulting image.

differenced image for input into dust RGB [10.8 - 8.7]

But the channel difference, which we scale from 0 to 15 degrees, effectively distinguishes dust clouds in black from desert (sand) surfaces, which provides vital additional information to the RGB.