  This article presents a synopsis of the activity in Jupiter's North
Equatorial Belt (NEB) from 1986 to 2010, and of the speeds of dark formations
on its south edge and bright streaks ('rifts') in its interior. In particular I
discuss NEB expansion events (NEEs), which took place every 3-5 years during
this time, and how the various features of the NEB are involved in them. I
present evidence that the NEE affects not just the northern edge, but the whole
width of the belt. It begins with an outbreak of a bright rift that is more
northerly and slower-moving than usual; this is often involved with the first
ejection of dark material northwards into the N. Tropical Zone, but typically
the rift also expands southwards across the width of the NEB. NEBs dark
formations are usually affected, as they are during individual interactions
with rifts at other times; they may be disrupted, or intensified, and they
usually undergo deceleration. The expansion of the dark NEB to the north occurs
concurrently, and is followed by the appearance of new dark 'barges' and white
ovals flanking the NEBn jet. The speed of the NEBs dark formations varies with
their mean spacing, consistent with the prevailing hypothesis that they are
planetary Rossby waves. In most apparitions since 2000 we have also detected
smaller, faster features (120 m/s). I propose that these represent waves of the
same type, but with higher frequency, and that their speed is slightly less
than the true wind speed at cloud-top level under normal conditions.
