Mathematician at Chalmers University of Technology and the University of Gothenburg
an overview for mathematicians
* images by NASA unless specified
Basic facts about Jupiter
- Largest gas giant (no solid surface)
- Primarily hydrogen and helium
- 79 known moons
- Jovian year: 11.86 y
- Jovian day: 9h 55m (average)
dark bands = belts
bright bands = zones
Exploration of Jupiter
- Earth-based observations (planet = from greek word "wanderer")
- Great red spot: Hooke (1664), Cassini (1665)
- Hubble Space Telescope (NASA), since 1990
- Many modern earth-based telescopes (including infra-red)
- Images from hobby astronomers (increasingly important source)
Most important spacecrafts
- Voyager 1 and 2 (flyby 1979)
- Cassini (flyby 2003)
- Galileo (orbiting 1995-2003)
- Juno (orbiting 2016-2021)
Time-lapse sequence from Voyager 1
"spots" are giant storms
Visible features occupy upper troposphere at ~1 bar
Reference: speed at equator ~12500 m/s (~1% fluctuations)
How deep are the jet streams?
Two competing theories:
- Shallow models: jet streams and vortices due to dynamics in shallow layer only
- Deep models: observed dynamics due to deep jet streams
However: deep models cannot account for vortex dynamics! => combined model needed
Great Red Spot (GRS)
- Diameter ~1.3 of Earth
- First observed 1665. How old is it?
- What makes its colour?
- Why is it stable?
Merging of storms
The dramatic events of June-July 2008
Oval BA: formed March 2000 (from 3 storms traced back to 1939)
Baby red spot
Circumpolar polygonal cyclones
Voyager 1981 and Cassini 2009
- What causes the hexagon shape?
Saturn's north pole
...but polygonally arranged cyclones do appear on Jupiter's poles!
One or several layers of 2D Euler
Valid for fast rotating fluids:
Interior organized into rotating "cylinders"
Fail to explain prograde equatorial jet
Fail to explain vortex formations
Basic question for mathematicians
- Which features of Jovian atmosphere dynamics are captured by the quasi geostrophic flow? (2D Euler)
- Reformulation: what is the "generic" behavior of 2D-Euler on rotating spheres?
Unstable Rossby-Haurwitz wave
By Klas Modin