Atmosphere of Jupiter

The atmosphere of Jupiter is the biggest planetary atmosphere in the Solar System. It is mostly made of molecular hydrogen and helium in about the same amounts as the Sun. Other things like methane, ammonia, hydrogen sulfide, and water are only found in tiny amounts. As you go deeper into Jupiter’s atmosphere, it slowly changes from gas to liquid, without a sharp line where this change happens.

Jupiter's swirling clouds, in a true-color image taken during fly-by of the Cassini-Huygens probe on 29th of December, 2000

Jupiter’s atmosphere has several layers, like the troposphere, stratosphere, thermosphere, and exosphere. The troposphere has clouds and hazy layers made of ammonia, ammonium hydrosulfide, and water. These clouds make stripes around the planet. Dark stripes are called belts, and light stripes are called zones. Strong winds, called jets, flow along these stripes, causing a spinning movement known as atmospheric super-rotation.

Jupiter’s atmosphere has lots of exciting weather, with big storms and swirling spots called vortices. The most famous is the Great Red Spot, a huge storm big enough to fit many Earths inside. These storms can sometimes make very strong lightning, much more powerful than lightning on Earth, as warm air moves up and creates tall, bright clouds.

Vertical structure

Vertical structure of the atmosphere of Jupiter. Note that the temperature drops together with altitude above the tropopause. The Galileo atmospheric probe stopped transmitting at a depth of 132 km below the 1 bar "surface" of Jupiter.

Jupiter's atmosphere has four layers: the troposphere, stratosphere, thermosphere, and exosphere. Unlike Earth's atmosphere, Jupiter does not have a mesosphere.

The troposphere is the lowest layer. It blends into Jupiter's fluid interior because Jupiter has no solid surface. The temperature in the troposphere gets colder as you go higher until it reaches its coldest point at the tropopause, about 50 km above the visible clouds.

In the stratosphere, temperatures begin to rise. The thermosphere continues this trend, with temperatures reaching up to 1000 K. Jupiter's clouds are made of different materials depending on their height. The highest clouds are made of ammonia ice, while lower clouds may contain ammonium hydrosulfide or water. The thermosphere shows beautiful glowing lights called aurorae and can emit X-rays.

Chemical composition

The atmosphere of Jupiter is mostly made of molecular hydrogen and helium. These two gases make up almost the entire atmosphere. Small amounts of other compounds are also present, including methane, ammonia, hydrogen sulfide, and water.

Scientists have studied Jupiter's atmosphere using spacecraft like the Galileo probe and telescopes. They found that Jupiter has a bit less helium than expected. Other elements like carbon, nitrogen, sulfur, and oxygen are found there.

Elemental abundances relative to hydrogen
in Jupiter and Sun
Element	Sun	Jupiter/Sun
He/H	0.0975	0.807±0.02
Ne/H	1.23×10⁻⁴	0.10±0.01
Ar/H	3.62×10⁻⁶	2.5±0.5
Kr/H	1.61×10⁻⁹	2.7±0.5
Xe/H	1.68×10⁻¹⁰	2.6±0.5
C/H	3.62×10⁻⁴	2.9±0.5
N/H	1.12×10⁻⁴	3.6±0.5 (8 bar) 3.2±1.4 (9–12 bar)
O/H	8.51×10⁻⁴	0.033±0.015 (12 bar) 0.19–0.58 (19 bar)^[b]
P/H	3.73×10⁻⁷	0.82
S/H	1.62×10⁻⁵	2.5±0.15

Isotopic ratios in Jupiter and Sun
Ratio	Sun	Jupiter
¹³C/¹²C	0.011	0.0108±0.0005
¹⁵N/¹⁴N	−3	(2.3±0.3)×10⁻³ (0.08–2.8 bar)
³⁶Ar/³⁸Ar	5.77±0.08	5.6±0.25
²⁰Ne/²²Ne	13.81±0.08	13±2
³He/⁴He	(1.5±0.3)×10⁻⁴	(1.66±0.05)×10⁻⁴
D/H	(3.0±0.17)×10⁻⁵	(2.25±0.35)×10⁻⁵

Zones, belts and jets

Jupiter shows bands running parallel to its equator. These bands are of two types: lighter-colored zones and darker belts. The wide Equatorial Zone stretches from about 7° South to 7° North. Above and below this, we find the North and South Equatorial belts, and further out, the North and South Tropical zones. These bands continue until around 50° latitude near the poles.

A polar stereographic projection of Jupiter's atmosphere centered about Jupiter's south pole

Zones look lighter because they have more ammonia, creating denser clouds higher up. Belts are darker with thinner clouds at lower heights. Between these bands flow fast winds called jets. These jets can speed up to over 100 meters per second and dive deep into Jupiter’s atmosphere.

The pattern of zones and belts may come from rising air in zones and sinking air in belts, similar to weather patterns on Earth. While the positions and speeds of these bands and jets stay mostly the same, their colors and details can shift over time.

Dynamics

Hubble images of Jupiter taken under the OPAL (Outer Planet Atmospheres Legacy) program from 2015 to 2024, with approximately true color.

Jupiter's atmosphere moves very differently from Earth's because Jupiter has no solid surface. Its interior is fluid all the way through. Scientists are still learning how its winds and weather work. They study two main ideas. One idea says that the weather happens only in a thin outer layer. The other idea says that the patterns we see come from deep currents inside the planet.

Both ideas have good points and problems. The thin-layer idea can explain some of Jupiter's wind bands but has trouble with others. The deep-current idea explains some features better but is still being tested. Scientists use both ideas to learn more about Jupiter's complex atmosphere.

Moist-convection and Y-shaped Structures on Jupiter's Equatorial Zone

Deep convection on Jupiter happens when water condenses under pressure, forming clouds. These clouds contain ammonia, hydrogen sulfide, and water. Deeper down, water becomes the main thing that forms clouds. Strong storms can mix ammonia and water to create special structures called "mushballs." These mushballs carry ammonia deeper into the atmosphere.

Y-shaped structures on Jupiter's equator might form when large heating creates a special shape. This shape is a mix of a stable form and a fast-moving wave. The structure moves eastward before breaking into separate parts. Moist convection is needed to start this process.

Internal heat

Jupiter gives off more heat than it receives from the Sun. This extra heat comes from Jupiter's early formation and possibly from helium sinking into its core. This internal heat helps keep Jupiter's atmosphere warm from the equator to the poles. Convection plays a key role in spreading the heat.

Main article: Internal heat

Discrete features

The atmosphere of Jupiter has many rotating structures called vortices. These come in two types: cyclones and anticyclones. Cyclones turn the same way as Jupiter, while anticyclones turn the opposite way. Anticyclones are more common, especially the bigger ones. These vortices can last from a few days to hundreds of years.

New Horizons IR view of Jupiter's atmosphere, false color

One famous feature is the Great Red Spot, a big anticyclonic storm seen for over 350 years. It is so large that two or three Earths could fit inside. Another storm is Oval BA, which formed in 2000 and turned red in 2006, called "Red Spot Jr."

Storms on Jupiter are like thunderstorms on Earth. They look like bright, clumpy clouds and are powered by lightning. These storms usually last only a few days, but sometimes they can last several months. Jupiter also has cyclones near its poles, studied by the Juno spacecraft. These cyclones make interesting patterns and help scientists learn about Jupiter's atmosphere.

Observational history

Main article: Exploration of Jupiter

Early astronomers used telescopes to watch Jupiter's atmosphere. They gave names to its different features like belts, zones, and spots. Later, space probes like Pioneer 10 and Pioneer 11 gave us closer looks. The Voyagers sent detailed images. Today, telescopes like the Hubble Space Telescope let scientists watch Jupiter's atmosphere change over time.

The Great Red Spot was first seen in the 1600s and has been studied ever since. In 1979, Voyager 1 sent back the first close-up pictures. Scientists also watch other storm shapes, like white ovals, which change and move over many years.