[16]  Circulating Current report July 25-31st (report, 2007 Aug 3rd)

Here is an update on the Circulating Current at STrD-1 (July 25-31); plus JUPOS charts showing the drifts of all the relevant spots until late July.
Thanks to all the observers, and to Hans-Joerg Mettig and colleagues in the JUPOS team <http://jupos.org>.

The dark spots on the SEBs jetstream are still performing the U-turn at STrD-1.  They are quite liable to overtake and merge, thus spots ab, de, and
fg, now on STBn, and spot L absorbing faster-moving spots on SEBs.  Please see the additional notes on the attached images and charts.

Meanwhile, changes are developing in the SEB between STrD-1 and the GRS. This sector is still very pale p. the GRS (with the blue streak Np. the GRS- typical of the faded state). But a gradual darkening of SEB(S) has spread f. STrD-1: it began as far back as July 10, and by July 26-28 it was obvious (as pointed out by Guillaume Bertrand and Chris Go). Meanwhile there is a dark spotty section of SEB(N) prograding p. the GRS.  The limits of the darkened sectors of SEB(S) and SEB(N) are very ill-defined but they are now overlapping, at L2 ~ 20-30 on
July 26-28, and more extensively on August 2.

Meanwhile, near the original source region, the whole SEB has been filled in with small-scale turbulent disturbance, from the GRS (L2 ~ 120) up to the
source (L2 ~ 180) (July 14-31).  Some small white spots continue to appear near the original source, but also in surrounding regions, and the
appearance is no different from the perennial post-GRS disturbance of previous years.

Note that the SED (now a long white area) passed the GRS around Aug.1; will it cause rifting or further disturbance in SEB(N) in the next few days?

_________________________________

John Rogers,
Jupiter Section Director,
British Astronomical Association.