Ensemble Space-Time Correlation of Plasma Turbulence in the Solar Wind

MATTHAEUS, W.H.; WEYGAND, J. M.; DASSO, S.

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2016 vol. 116 p. 245101 - 245106

0031-9007

Single point measurement turbulence cannot distinguish variations in space and time. We employ anensemble of one- and two-point measurements in the solar wind to estimate the space-time correlationfunction in the comoving plasma frame. The method is illustrated using near Earth spacecraft observations,employing ACE, Geotail, IMP-8, and Wind data sets. New results include an evaluation of both correlationtime and correlation length from a single method, and a new assessment of the accuracy of the familiarfrozen-in flow approximation. This novel view of the space-time structure of turbulence may proveessential in exploratory space missions such as Solar Probe Plus and Solar Orbiter for which the frozen-inflow hypothesis may not be a useful approximation.