Origin of Jupiter’s GRS

[Jeremy Shears]

Interesting submission to Geophysical Research Letters on ArXiv today: https://arxiv.org/abs/2406.13222
The authors discuss the origin and evolution of the GRS, including that the current GRS wasn’t the same object observed by Cassini.

[David Arditti]

This has certainly long been John Roger’s view, that Cassini’s spot was not the current one. 19th Century drawings and early photographs show the GRS as a huge pale area at that time, unlike Cassini’s more concentrated dark spot. It seems likely Cassini was seeing a late stage of a contracting, darkening and accelerating spot, just as we are now seeing the similar late phase of the 19th C GRS.

[John Rogers]

Yes, their historical account is essentially the same as in my 1995 book, which fortunately they do cite thoroughly — and brought up to date, of course. The idea that the GRS formed from a South Tropical Disturbance was also proposed in my book. What’s new, and very welcome, is that they have done computational simulations that show this to be physically plausible.

[Author]

Posts