Jupiter—Roman God of Sky
and Thunder—King of the Gods
"Jupiter et Thétis" by Jean Ingres, 1811
Jupiter ─ Coming Up









What observations from Earth reveal about Jupiter
Jupiter’s composition
Jupiter’s structure
How Jupiter rotates differently than terrestrial planets
The nature of Jupiter’s immense storms
How Jupiter’s internal heat drives activity in its
atmosphere
The effect of ‘Coriolis forces’ on Jupiter’s atmosphere
What the Galileo space probe revealed about
Jupiter’s atmosphere
How Jupiter’s intense magnetic field is produced by
an exotic form of hydrogen
Jupiter—As Seen From Earth
Jupiter
•
From Earth (2.6 m Nordic Telescope, Canary Islands)
• Jupiter and Io
• Voyager 2, 1979
•
Ganymede’s
shadow
•
Io
What is the physical appearance of
Jupiter as seen from Earth or a
spacecraft?
A.a series of dark belts and light
zones parallel to its equator
B.a uniform bluish color with a
high-level haze
C.v-shaped cloud forms around its
equator, indicative of rapid winds
D.uniform red-colored dust clouds
over a heavily cratered surface
Google: "The Man in the Green Hat.“
The Coriolis Force
Named after the French Scientist Gaspard Gustave Coriolis
Because of the Earth’s
rotation, free moving
objects …
• deflected to the right in
the Northern Hemisphere
• to the left in the Southern
Hemisphere
• Depends on an object’s
speed—higher speed
means stronger Coriolis
Force.
A Pressure Gradient
North Latitude
H
Pressure (mb)
1017
1015
• A pressure gradient
causes wind to blow
straight from High P
to Low P and
accelerate as it goes
1013
1011
1009
Equator
1007
L
Pressure, Coriolis Force, Friction
North Latitude
H
Pressure (mb)
1017
• Wind doesn’t blow
straight from High to
Low … curves to the
right of straight line.
1015
• H and L don’t last
forever without energy
source … why?
1011
1013
1009
Equator
Rotation of Earth
1007
L
Atmospheric Circulation on
Slowly Rotating Earth
What are the major factors that cause
winds to flow from east to west and
west to east in alternating bands that
encircle the Earth?
A. Carbon dioxide in Earth’s
atmosphere.
B. Earth has an extensive ring system.
C. The gulf stream in the Atlantic and
El Nino in the Pacific.
D. Atmospheric convection and
rotation of the Earth.
Curved Flow around High and Low
Cyclonic Flow
Anticyclonic Flow
Actual flow around pressure systems are never this regular .
Cyclones and Anti–Cyclones
Around a surface low pressure center, net inward transport of
air causes a convergence … air rises in the center.
Around a surface high pressure center, net outward transport
of air causes a divergence … air falls in the center.
Anti–Cyclones
Anticyclones : high pressures
with nearly circular isobars.
• Air descends toward surface
due to convergence aloft.
• As air nears surface it is
forced outward (divergence).
• Coriolis effect bends air to the
right of its path creating a
clockwise rotation.
• Under
an anticyclone, air is descending, forming an area of
higher pressure at the surface.
• Cloud formation is inhibited, so the weather is usually settled
with only small amounts of cloud cover.
Cyclone
Cyclones: Low pressures that
exhibit nearly circular isobars.
• As air enters low pressure from
all directions, Coriolis effect bends
wind direction to the right of its
path.
• This creates counterclockwise
rotation around the low
and convergence near the center.
• As air collides near center it is
forced aloft where divergence
takes air away from the center.
• Upper-level divergence maintains low pressure.
• Rising air cools,condenses helps cloud formation, so weather
associated with cyclone is cloudy and wet.
Cassini 4-image Composite
of Jupiter (2000 Flyby)
Solid rotation typifies the
terrestrial planets: Every
part of the object takes
exactly the same time to
complete one rotation.
Differential rotation typifies
Jupiter: Particles at different
locations in the fluid take
different lengths of time to
complete one rotation.
What causes Jupiter's belts and zones?
A. Electrical conduction in Jupiter’s
liquid metallic hydrogen layer that
causes electrons to swirl around the
planet
B. The “sweeping” of Jupiter's clouds
through magnetic field lines from
Jupiter's magnetosphere
C. Convection in Jupiter’s atmosphere,
stretched into bands by strong Coriolis
forces due to Jupiter's rapid rotation
D. Electric force fields set up by an
advanced civilization set up to protect
Jupiter from alien attack
Zones appear dark
because their high-altitude
clouds are cold.
Belts appear bright
because we see to
warmer depths of the
atmosphere.
The Great Red Spot (a region
of cool, high-altitude clouds)
appears dark.
Infrared Image
Pioneer 11—December 1974
Note the Great Red
Spot and Surroundings
Voyager 2—July 1979
HST—February 1995
Winds on the north side of the
Great Red Spot flow westward.
Turbulence downwind
of the Great Red Spot
Winds within the Great Red Spot
circulate counterclockwise.
20,000 km
Winds on the south side of the
Great Red Spot flow eastward.
Earth’s Diameter
The Great Red Spot most probably is
________.
A. clouds of dust-laden gas rising up
over the top of a massive
mountain or a volcano on the
planet's surface
B. a large, long-lived, high-pressure
storm in Jupiter's atmosphere
C. the colored polar ice cap of
Jupiter
D. a large, red zit that appeared on
Jupiter’s nose after coupling with
Juno
Galileo Probe Enters Jupiter
Jupiter’s Magnetosphere
Strongest radio emission from electrons trapped
in current sheet
The material in the interior of Jupiter
thought to be responsible for its
powerful magnetic field is_____.
A. molten iron and nickel
B. liquid metallic hydrogen
C. gasses of NH3 (ammonia), CH4
(methane) and H2O (water vapor)
D. solid magnetic iron
Jupiter’s Main Ring
Key Ideas
Composition and Structure:




Jupiter’s mass is 318 ME and its volume is over 1000
Earths. Overall composition–86% hydrogen, 12%
helium, and 2% other elements by numbers.
Jupiter probably has a rocky core several times more
massive than the Earth.
The core is surrounded by a layer of liquid “ices” (water,
ammonia, methane, and associated compounds).
The “ices” are surrounded by a layer of helium and liquid
metallic hydrogen and an outermost layer composed
primarily of ordinary hydrogen and helium.
Key Ideas



Jupiter rotates so rapidly that it is noticeably “flattened.”
Its interior rotation is revealed by variations in its radio
emission.
Jupiter emits about 2 x more energy than it receives from
the Sun—probably it is still cooling.
Key Ideas
Atmosphere:



The visible “surface” of Jupiter is actually the tops of its
clouds. The rapid rotation of the planets twists the clouds
into dark belts and light zones that run parallel to the
equator. Strong zonal winds run along the belts and
zones.
The outer layers of the atmosphere show differential
rotation—the equatorial regions rotate slightly faster than
the polar regions. The polar rotation rate is nearly the
same as the internal rotation rate.
The colored ovals visible in the Jovian atmosphere
represent gigantic storms. Some, such as the Great Red
Spot, are quite stable and persist for many years.
Key Ideas
Clouds:


There are presumed to be three cloud layers in Jupiter’s
atmosphere made of NH3, NH4SH and H2O ices, which
are all white crystals.
The reasons for the distinctive colors of these different
layers are not yet known, but probably are caused by
long chain molecules containing sulfur and phosphorus.
Key Ideas
Magnetic Field and Magnetosphere:


Jupiter has a strong magnetic field created by currents in
the metallic hydrogen layer. Its huge magnetosphere
contains a vast current sheet of electrically charged
particles. Charged particles in the densest portions of
Jupiter’s magnetosphere emit synchrotron radiation at
radio wavelengths.
The Jovian magnetosphere encloses a low-density
plasma of charged particles. The magnetosphere exists
in a delicate balance between pressures from the
plasma and from the solar wind. When this balance is
disturbed, the size of the magnetosphere fluctuates
drastically.