<P> The North Temperate Region is part of a latitudinal region easily observable from Earth, and thus has a superb record of observation . It also features the strongest prograde jet stream on the planet--a westerly current that forms the southern boundary of the North Temperate Belt (NTB). The NTB fades roughly once a decade (this was the case during the Voyager encounters), making the North Temperate Zone (NTZ) apparently merge into the North Tropical Zone (NTropZ). Other times, the NTZ is divided by a narrow belt into northern and southern components . </P> <P> The North Tropical Region is composed of the NTropZ and the North Equatorial Belt (NEB). The NTropZ is generally stable in coloration, changing in tint only in tandem with activity on the NTB's southern jet stream . Like the NTZ, it too is sometimes divided by a narrow band, the NTropB . On rare occasions, the southern NTropZ plays host to "Little Red Spots". As the name suggests, these are northern equivalents of the Great Red Spot . Unlike the GRS, they tend to occur in pairs and are always short - lived, lasting a year on average; one was present during the Pioneer 10 encounter . </P> <P> The NEB is one of the most active belts on the planet . It is characterized by anticyclonic white ovals and cyclonic "barges" (also known as "brown ovals"), with the former usually forming farther north than the latter; as in the NTropZ, most of these features are relatively short - lived . Like the South Equatorial Belt (SEB), the NEB has sometimes dramatically faded and "revived". The timescale of these changes is about 25 years . </P> <P> The Equatorial Region (EZ) is one of the most stable regions of the planet, in latitude and in activity . The northern edge of the EZ hosts spectacular plumes that trail southwest from the NEB, which are bounded by dark, warm (in infrared) features known as festoons (hot spots). Though the southern boundary of the EZ is usually quiescent, observations from the late 19th into the early 20th century show that this pattern was then reversed relative to today . The EZ varies considerably in coloration, from pale to an ochre, or even coppery hue; it is occasionally divided by an Equatorial Band (EB). Features in the EZ move roughly 390 km / h relative to the other latitudes . </P>

Hydrogen is the most abundant element in jupiter's atmosphere