Developing or Dissipating Fog
Examine the animation. Then decide if each area highlighted on the image below it is experiencing fog and, if so, if it’s thickening/developing or dissipating between 0000 UTC and 0400 UTC.
Question 1
Which areas are experiencing thickening fog? Select all that apply.
The correct answers are A, B, and C.
There’s little to no indication of fog in these areas at the outset (0000 UTC). But as the animation progresses to 0100 and 0200 UTC, the light blue shade indicating fog develops. This means that the fog is developing/thickening.
Question 2
What is happening in area D?
The correct answer is C.
There’s good indication of fog at the outset (0000 UTC). But as the animation progresses towards 0400 UTC, the light blue shade indicating fog shrinks. This means that the fog is dissipating during this period.
This example highlights the importance of knowing when sunrise occurs and how it impacts the night microphysical RGB. Play the animation again, focusing on Madagascar. You’ll see that the area of fog suddenly turns pink. This is caused by sunrise. It impacts IR 3.9 channel’s contribution to the night microphysical RGB, changing the colour of the image. So you should always be mindful of when sunrise occurs so you’re not confused when an area with fog at one time step suddenly turns pink!