title: Reorientation of the large-scale circulation in turbulent Rayleigh-Bénard convection.
abstract: We present measurements of the orientation theta0(t) of the large-scale circulation (LSC) of turbulent Rayleigh-Bénard convection in cylindrical cells of aspect ratio 1. Theta0(t) undergoes irregular reorientations. It contains reorientation events by rotation through angles delta theta with a monotonically decreasing probability distribution p(delta theta), and by cessations (where the LSC stops temporarily) with a uniform p(delta theta). Reorientations have Poissonian statistics in time. The amplitude of the LSC and the magnitude of the azimuthal rotation rate have a negative correlation.
authors.affiliation: Department of Physics and iQUEST, University of California, Santa Barbara, California 93106, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Brown
authors.forename: Alexei
authors.initials: A
authors.lastname: Nikolaenko
authors.forename: Guenter
authors.initials: G
authors.lastname: Ahlers