Long-lasting, deep effect of Saturn's giant storms.

Area of Science:

• Planetary Science
• Atmospheric Science
• Radio Astronomy

Background:

• Saturn experiences quasiperiodic, planetary-scale giant storms.
• The Cassini mission extensively documented the 2010 storm event.
• Understanding deep atmospheric responses to these storms is crucial.

Purpose of the Study:

• To probe the deep tropospheric response of Saturn to giant storms using radio observations.
• To identify and map long-lasting signatures of past and present storms.
• To investigate the vertical transport and meridional migration of atmospheric constituents like ammonia.

Main Methods:

• Utilized the Very Large Array (VLA) for radio observations of Saturn's troposphere in 2015.
• Analyzed observational data to derive an ammonia anomaly map.
• Interpreted storm aftermath signatures and their latitudinal distribution.

Main Results:

• Detected long-lasting signatures of multiple mid-latitude giant storms, some potentially hundreds of years old.
• Observed extensive meridional migration of storm aftermath and vertical ammonia transport.
• The 2010 storm's remnants split into two components, moving poleward and equatorward from 43°N.

Conclusions:

• Giant storms induce persistent changes in Saturn's deep troposphere.
• Storm dynamics play a significant role in the vertical and horizontal transport of ammonia.
• Saturn's atmospheric memory of giant storms is extensive and complex, with evidence of ancient events.