  We use an infrared dataset captured between 1984 and 2017 using several
instruments and observatories to report five rare equatorial disturbances that
completely altered the appearance of Jupiter's Equatorial Zone (EZ): the
clearance of tropospheric clouds revealed a new 5-$\mu$m-bright band encircling
the planet at the equator, accompanied by large 5-$\mu$m-bright filaments.
Three events were observed in ground-based images in 1973, 1979 and 1992. We
report and characterize for the first time the entire evolution of two new
episodes of this unusual EZ state that presented their maximum
5-$\mu$m-brightness in December 1999 and February 2007, coinciding with a brown
coloration south of the equator and with large bluish filaments and white
plumes in the northern EZ at visible wavelengths. We characterize their typical
infrared-bright lifetimes of 12-18 months, with possible periodicities of 6-8
or 13-14 years. We predict that a full-scale equatorial disturbance could occur
in 2019-21.
