what are the alternating dark and light bands in jupiter’s atmosphere called
Atmosphere of Jupiter The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the planet.[3] From lowest to highest, the atmospheric layers are the troposphere, stratosphere, thermosphere and exosphere. Each layer has characteristic temperature gradients.[4] The lowest layer, the troposphere, has a complicated system of clouds and hazes, comprising layers of ammonia, ammonium hydrosulfide and water.[5] The upper ammonia clouds visible at Jupiter's surface are organized in a dozen zonal bands parallel to the equator and are bounded by powerful zonal atmospheric flows (winds) known as jets. The bands alternate in color: the dark bands are called belts, while light ones are called zones. Zones, which are colder than belts, correspond to upwellings, while belts mark descending gas.[6] The zones' lighter color is believed to result from ammonia ice; what gives the belts their darker colors is uncertain.[6] The origins of the banded structure and jets are not well understood, though a "shallow model" and a "deep model" exist.[7]