HR: 08:45h
AN: SH11B-04    [PDF]
TI: Three dimensional correlations in the solar wind: the two component model revisited.
AU: * Milano, L J
EM: lmilano@bartol.udel.edu
AF: Bartol Research Institute, University of Delaware, 217 Sharp Lab, Newark, DE 19716 United States
AU: Dasso, S
EM: sdasso@iafe.uba.ar
AF: Instituto de Astronomia y Fisica del Espacio, Edificio IAFE Ciudad Universitaria, Buenos Aires, BUE 1428 Argentina
AU: Matthaeus, W H
EM: yswhm@bartol.udel.edu
AF: Bartol Research Institute, University of Delaware, 217 Sharp Lab, Newark, DE 19716 United States
AU: Smith, C W
EM: Charles.Smith@unh.edu
AF: Institute for Earth, Oceans and Space, University of New Hampshire, 39 College Road, Durham, NH 03824y United States
AB: Observations and theory motivate models of solar wind fluctuations consisting of two components-- ``slab'' Alfven waves varying mainly parallel to the ambient dc magnetic field, and a zero-frequency quasi two-dimensional turbulent component varying mainly perpendicular to the magnetic field. We present an extension of the previous analysis, employing ACE plasma and magnetic field data, to examine three dimensional correlations and spectra for the cross helicity, velocity, magnetic and Elsasser fluctuations. We find surprisingly that all quantities have similar anisotropic structure, thus implying that the normalized cross helicity, a measure of the strength of the non-linear terms, is essentially isotropic. This conclusion stands in contrast to the usual assumption that the slab component, as propagating waves, carries most of the cross helicity. This calls for some revision in standard solar wind turbulence models.
DE: 2149 MHD waves and turbulence
DE: 2164 Solar wind plasma
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting