EGU21-16226, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The evolution of Jupiter polar cyclones

Alessandro Mura1, Christina Plainaki2, Giuseppe Sindoni2, Alberto Adriani1, Davide Grassi1, Marisa Moriconi3, Alessandro Ciarravano3, Giuseppe Piccioni1, Alessandra Migliorini1, and Roberto Sordini1
Alessandro Mura et al.
  • 1INAF, IAPS, Rome, Italy (
  • 2ASI, Rome, Italy
  • 3CNR, Rome Italy

JIRAM (the Jovian InfraRed Auroral Mapper) is an infrared camera and
spectrometer on board Juno. JIRAM operates in the 2-5 μm spectral
range and is built to observe both Jupiter's infrared aurora and its
atmosphere. Since 2016, JIRAM has performed several observations of
the polar regions of the planet, thanks to the unique orbital design
of the Juno mission.  In the north polar region, Juno discovered, in
2017, the presence of an eight-cyclone structure around a single polar
cyclone; to the south, a polar cyclone is surrounded by five
circumpolar cyclones. The stability of these structures has been
monitored for almost 4 years. Recent observations, made at the end of
2019, showed that the configuration of the South Pole has temporarily
changed: the structure moved in a hexagon for a few months, before
returning to its original pentagonal shape. To the north, there are
significant hints that the octagonal shape may have been lost for a
similar period of time.
We find that all cyclones show a very slow, westward drift as a rigid
ensemble, and, in addition, they oscillate around their rest position
with similar timescales. These oscillations seem to propagate from
cyclone to cyclone. The implications of these transient deviations
from the symmetrical forms, which appear to be an apparent condition
of equilibrium, are discussed.

How to cite: Mura, A., Plainaki, C., Sindoni, G., Adriani, A., Grassi, D., Moriconi, M., Ciarravano, A., Piccioni, G., Migliorini, A., and Sordini, R.: The evolution of Jupiter polar cyclones, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16226,, 2021.