Journal
ASTROPHYSICAL JOURNAL LETTERS
Volume 919, Issue 2, Pages -Publisher
IOP Publishing Ltd
DOI: 10.3847/2041-8213/ac21d2
Keywords
-
Categories
Funding
- NASA Heliophysics Supporting Research [80NSSC18K1210, 80NSSC18K1648]
- NASA Heliophysics Guest Investigator grant [80NSSC19K0284]
- NASA IMAP project from Princeton University [SUB0000317]
- NASA PUNCH project under SWRI [N99054DS]
- Argentinean grants UBACyT (UBA)
Ask authors/readers for more resources
Research shows that there exists a similarity decay phenomenon similar to fluid turbulence in the magnetic field fluctuations of the solar wind, which is significant for theoretical studies of the magnetic field. By analyzing magnetic correlation functions obtained from different data sources, it can be concluded that the second-order magnetic correlation functions largely conform to the similarity form anticipated by von Karman's hypothesis.
A major development underlying much of hydrodynamic turbulence theory is the similarity decay hypothesis due to von Karman and Howarth here extended empirically to magnetic field fluctuations in the solar wind. In similarity decay the second-order correlation experiences a continuous transformation based on a universal functional form and a rescaling of energy and characteristic length. Solar wind turbulence follows many principles adapted from classical fluid turbulence, but previously this similarity property has not been examined explicitly. Here we analyze an ensemble of magnetic correlation functions computed from Advanced Composition Explorer data at 1 au, and demonstrate explicitly that the two-point correlation functions undergo a collapse to a similarity form of the type anticipated from von Karman's hypothesis. This provides for the first time a firm empirical basis for employing the similarity decay hypothesis to the magnetic field, one of the primitive variables of magnetohydrodynamics, and one frequently more accessible from spacecraft instruments. This approach is of substantial utility in space turbulence data analysis, and for adopting von Karman-type heating rates in global and subgrid-scale dynamical modeling.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available