National Aeronautics and Space Administration

Living With A Star

Targeted Research and Technology

Turbulent heating of the corona, origin of solar wind fluctuations, and boundary conditions in the inner heliosphere

ROSES ID: NNH05ZDA001N      Selection Year: 2006      

Program Element: Data, Tools, & Methods

Principal Investigator: William Matthaeus

Affiliation(s): University of Delaware

Project Member(s):
Velli, Marco CM Co-I University of California, Los Angeles


This proposal is to support collaborative work on the origins of the solar wind,

and the boundary conditions for Space Weather effects in the inner

heliosphere, to be carried out during a one year sabbatical that the

PI has been granted by the University of Delaware for calendar year 2006.

The University will supply 75% of the PI's salary in support of the sabbatical,

and this proposal requests support for the remaining 25%.

During the year the PI will spend approximately five months at the University

of Florence to work collaboratively with Prof. Marco Velli. The PI and Prof. Velli

both served on the Solar Probe Science and Technology Definition team

and contributed substantially to the science component of that effort.

The goals of this proposal are based on science issues that came up and

became partially clarified while writing the solar probe Science and Technology

Definition Team document, providing a unique opportunity to continue the

momentum that was established in that series of meetings. The proposed

research is:

(1) to develop a better theoretical understanding of the behavior of

Alfven waves and turbulence in the important regions between the sonic and

Alfven points (approx. 5-20 Rs) in the corona, and between the Alfven point

and 1AU in the solar wind. This includes study of observed 1/f noise, the

development of anisotropy, and the nature of high latitude turbulence. These

will be addressed through a combination of observational and numerical inputs,

and analytical modeling;

(2) to assemble a fully consistent model of the acceleration of the solar wind,

using for the first time an accurate, consistent and tested nonlinear model for

MHD turbulence starting in the lower corona. Unlike other similar models, we

will include cross helicity and anisotropic cascade effects. These are issues

that the PI has worked on in great detail with his collaborators, and in this new

collaboration M. Velli will supply valuable expertise in wind equations and

modeling of large scale coronal magnetic field. The further understanding of

the plasma physics and turbulence theory of these regions will provide extremely

valuable insights concerning the "inner boundary conditions" for space weather,

and is therefore an essential underpinning of the LWS TRT science in general,

directly addressing the 2005 targeted research area: "T3b. Determine the

mechanisms that heat and accelerate the solar wind." This is a one

year proposal, but the PI agrees to maintain participation in the associated

working group.


Performance YearReferenceInvestigation TypeActions
1Smith, Charles W.; Isenberg, Philip A.; Matthaeus, Wi...
not set
1Breech, B.; Matthaeus, W. H.; Minnie, J.; Bieber, J....
not set
1Usmanov, A. V.; Matthaeus, W. H.; Breech, B.; Goldst...
not set
1Isenberg, Philip A.; Oughton, Sean; Smith, Charles W....
not set
1Usmanov, Arcadi V.; Matthaeus, William H.; Breech, Be...
not set

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