HR: 11:25h
AN: SH32B-05 [Abstracts]
TI: Solar Wind Measurements of the Alignment Between Vector Velocity and Magnetic Field Fluctuations and Comparisons to Boldyrev's Phenomenological Theory
AU: * Podesta, J J
EM: j.podesta@unh.edu
AF: Center for Integrated Computation and Analysis of Reconnection and Turbulence,
University of New Hampshire, Durham, NH 03824, United States
AU: Bhattacharjee, A
EM: amitava.bhattacharjee@unh.edu
AF: Center for Integrated Computation and Analysis of Reconnection and Turbulence,
University of New Hampshire, Durham, NH 03824, United States
AU: Chandran, B D
EM: benjamin.chandran@unh.edu
AF: Center for Integrated Computation and Analysis of Reconnection and Turbulence,
University of New Hampshire, Durham, NH 03824, United States
AB:
Boldyrev's phenomenological theory of incompressible MHD turbulence predicts that as energy cascades from
large to small scales through the inertial range the components of velocity and magnetic field fluctuations
perpendicular to the mean magnetic field become progressively more aligned with each other so that the angle
between them decreases monotonically like λ1/4, where λ is the length scale of the
fluctuations perpendicular to the mean magnetic field. Studies undertaken to search for this scaling law in solar
wind data have shown that such a scaling law holds at the largest inertial range scales but then breaks down at
intermediate to small scales. Analysis of data from the Wind spacecraft at 1 AU show a power law scaling exists
from roughly 5× 104 to 103 seconds with a power law exponent similar to the predicted value 1/4.
The scaling law disappears at smaller scales with the alignment angle reaching a minimum between 103
and 102 seconds and then increasing as the scale size decreases further down to 10 seconds or so.
DE: 2149 MHD waves and turbulence (2752, 6050, 7836)
DE: 4475 Scaling: spatial and temporal (1872, 3270, 4277)
DE: 4490 Turbulence (3379, 4568, 7863)
DE: 7839 Nonlinear phenomena (4400, 6944)
DE: 7863 Turbulence (4490)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting