Jupiter in 2019, Report no.4

This report covers activity on Jupiter up to early May.  It includes:

--A zonal wind profile made by Marco Vedovato from amateur images on 2019 April 19-21.

--Maps of the planet in April, and images of the EZ during Juno's fly-over at Perijove-19.

--Detailed coverage of the action around the GRS, where incoming ring-shaped vortices on the SEBs jet have been causing red 'flakes' to detach from the f. end of the GRS, and now also from its p. end.  Recently a strikingly dark grey collar has also formed around the GRS.  Links to animations are given, and a summary of past history of such red flakes. 

--Tracking the STB Spectre, which has grown to ~70 deg long, in methane images; its p. end has now arrived alongside the GRS.

The text of the report is here (PDF):      JupLet 2019cc_Report-no4.pdf

Miniatures of the figures are here (PDF):     Report-no4_Figures.pdf

The full-size figures are here (ZIP):      Jup-2019_Report-no4_Figures.zip

Two animations of maps of the GRS activity (north up, south up) are here:

A labelled map of the planet is below.