A giant anticyclonic storm raging in the southern…
A giant anticyclonic storm raging in the southern hemisphere of Jupiter, the largest planet in our solar system. Wider than Earth, it has been observed continuously since at least the nineteenth century, and possibly since the 1660s. Its swirling winds can reach hundreds of kilometres per hour. Its brick or salmon colour may come from chemicals broken down by sunlight. Measurements show that the oval has been shrinking for decades.
The answer in 12 letters
One definition, one title to guess: that's WordLocus. This one comes from a past challenge.