[Quark (Trevor)]

Hi All,

Not sure whether to post this here or in the Astronomy Science Forum. Posted here as there have been several Saturn images posted over the last month or so that had the EZn cloud system in them.

Back on 25/01/2009 I posted images and an animation of possible new storm structure on Saturn. As most here know, I am part of an international team regularly contributing data to Dr Georg Fischer.

I thought the info Georg supplied to me this morning may be of general interest.

Attached is an image taken by Cassini 27/01/2009 that Georg refers to.
Dr Georg Fischer is recognized as a world leading authority on this subject.

Georg is currently in Graz Austria, he works for the Space Research Institute at the Austrian Academy of Sciences

Explanation of terms;
SED's = Saturn Electrostatic Discharge
RPWS = Radio & Plasma Wave Science, refers to the instrument onboard the Cassini space craft that detects SED's, that is lightning in the atmosphere of Saturn.

Regards
Trevor

Hi Trevor,

I have heard in the news about this terrible heat wave in Australia. When I look out the window of my office it is just snowing here....so hopefully it will get cooler soon in Down Under.

The last SEDs RPWS detected are from January 27, but as you know, that does not mean that the storm must be over. I have attached you a Cassini image also from January 27, and the cloud system can be still seen pretty good (on the right side in the middle).

This long-lived cloud system in the equatorial zone is quite interesting, although, up to now, there still seems to be no lightning coming from there. Maybe this will change soon. When the Voyagers were at Saturn, soon 29 years ago, there was also equinox, so it was exactly the same season. And both Voyagers detected SEDs (in Nov. 1980 and August 1981) from an equatorial storm system. This system was not imaged, but from the periodicity of SED episodes around 10 hours 10 min., the equatorial region was the only possible source. So I kind of expect the development of a long-lived equatorial storm system. The occurrence of SED storms in the various latitudinal bands could be related to seasonal effects. One reason for an equatorial storm around equinox could be the sharp ring shadow, causing temperature gradients and possibly triggering storms in Saturn's atmosphere.

Cheers,

Georg