The lightning strikes on Jupiter are hundreds of times more powerful than those seen on Earth, and are assumed to be associated with the water clouds. They are sites of strong upward motion of the air, which leads to the formation of bright and dense clouds. The storms are a result of moist convection in the atmosphere connected to the evaporation and condensation of water. Jupiter has powerful storms, often accompanied by lightning strikes. Oval BA, south of GRS, is a red spot a third the size of GRS that formed in 2000 from the merging of three white ovals. It could engulf two or three Earths and has existed for at least three hundred years. Located in the southern hemisphere, the GRS is the largest known vortex in the Solar System. Vortices are thought to be relatively shallow structures with depths not exceeding several hundred kilometers. These two and most of the other large spots are anticyclonic. The largest two spots are the Great Red Spot (GRS) and Oval BA, which is also red. The vortices reveal themselves as large red, white or brown spots (ovals). The Jovian atmosphere shows a wide range of active phenomena, including band instabilities, vortices ( cyclones and anticyclones), storms and lightning. The origins of the banded structure and jets are not well understood, though a "shallow model" and a "deep model" exist. The zones' lighter color is believed to result from ammonia ice what gives the belts their darker colors is uncertain. Zones, which are colder than belts, correspond to upwellings, while belts mark descending gas. The bands alternate in color: the dark bands are called belts, while light ones are called zones. 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 lowest layer, the troposphere, has a complicated system of clouds and hazes, comprising layers of ammonia, ammonium hydrosulfide and water.
Each layer has characteristic temperature gradients. From lowest to highest, the atmospheric layers are the troposphere, stratosphere, thermosphere and exosphere. The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the planet. The nitrogen, sulfur, and noble gas abundances in Jupiter's atmosphere exceed solar values by a factor of about three. Although water is thought to reside deep in the atmosphere, its directly measured concentration is very low. It is mostly made of molecular hydrogen and helium in roughly solar proportions other chemical compounds are present only in small amounts and include methane, ammonia, hydrogen sulfide, and water. The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. Jupiter's swirling clouds, in a true-color image taken by the Hubble Space Telescope in April 2017