October 26, 2012, 12:00 pm - 1:00 pm

October 26, 2012, 12:00 pm - 1:00 pm, Heliophysics Director's Seminar

Voyager and IBEX Multi-Spectral Views Towards the Interstellar Boundary Zone: Are We There Yet?

Dr. John F. Cooper, NASA Goddard Space Flight Center

Recent cosmic ray data from Voyager 1 clearly indicate that the spacecraft has passed through an unusual region of the heliosheath and may now be in a transitional zone inwards of, or perhaps within, the very local interstellar environment. The magnetic field, ion, and neutral atom distributions bounding and within this zone could be critical to understanding of the outer heliospheric boundary, the heliopauise, and of the origin of the IBEX "ribbon".

What controls the outer scale of turbulence in the solar wind?

Dr. Robert T. Wicks, NASA Goddard Space Flight Center

The outer scale is the largest scale in the turbulent inertial range. We know that this scale grows larger with increasing distance from the Sun and that high cross-helicity can make the outer scale smaller, possibly accounting for the differences in turbulent spectra between fast and slow wind. Here I will dissect a single fast stream and show that the cross-helicity and residual-energy of individual fluctuations controls their turbulent cascade and in particular the outer scale.

DSCOVR High Time Resolution Solar Wind Measurements

Dr. Adam Szabo, NASA Goddard Space flight Center

The Deep Space Climate Observatory (DSCOVR), previously known as Triana, spacecraft is expected to be launched in late 2014. It will carry a fluxgate magnetometer, Faraday Cup solar wind detector and a top-hat electron electrostatic analyzer. The Faraday Cup will provide an unprecedented 10 vectors/sec time resolution measurement of the solar wind proton and alpha reduced distribution functions. Coupled with the 40 vector/sec vector magnetometer measurements, the identification of specific wave modes in the solar wind will be possible for the first time.