  For rapidly rotating turbulent Rayleigh--B\'enard convection in a slender
cylindrical cell, experiments and direct numerical simulations reveal a
boundary zonal flow (BZF) that replaces the classical large-scale circulation.
The BZF is located near the vertical side wall and enables enhanced heat
transport there. Although the azimuthal velocity of the BZF is cyclonic (in the
rotating frame), the temperature is an anticyclonic traveling wave of mode one
whose signature is a bimodal temperature distribution near the radial boundary.
The BZF width is found to scale like $Ra^{1/4}Ek^{2/3}$ where the Ekman number
$Ek$ decreases with increasing rotation rate.
