On the relationship between coronal heating, magnetic flux, and the density of the solar wind

Details On the relationship between coronal heating, magnetic flux, and the density of the solar wind On the relationship between coronal heating, magnetic flux, and the density of the solar wind

Jun 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010jgra..11506104r&link_type=abstract

Journal of Geophysical Research, Volume 115, Issue A6, CiteID A06104

Astronomy and Astrophysics

Astrophysics

5

Interplanetary Physics: Solar Wind Plasma, Interplanetary Physics: Interplanetary Magnetic Fields, Interplanetary Physics: Solar Wind Sources, Solar Physics, Astrophysics, And Astronomy: Coronal Holes, Solar Physics, Astrophysics, And Astronomy: Magnetic Fields

Scientific paper

The stark differences between the current solar minimum and the previous one offer a unique opportunity to develop new constraints on mechanisms for heating and acceleration of the solar wind. We have used a combination of numerical simulations and analysis of remote solar and in situ observations to infer that the coronal heating rate, H, scales with the average magnetic field strength within a coronal hole, Bch. This was accomplished in three steps. First, we analyzed Ulysses measurements made during its first and third orbit southern and northern polar passes (i.e., during near-solar minimum conditions) to deduce a linear relationship between proton number density (np) and radial magnetic field strength (Br) in the high-speed quiescent solar wind, consistent with the results of McComas et al. (2008) and Ebert et al. (2009). Second, we used Wilcox Solar Observatory measurements of the photospheric magnetic field to show that the magnetic field strength within coronal holes (Bch) is approximately correlated with the strength of the interplanetary field at the location of Ulysses. Third, we used hydrodynamic simulations to show that np in the solar wind scales linearly with H. Taken together, these results imply the chain: H $\propto$ np $\propto$ Br $\propto$ Bch. We also explored ideas that the correlation between np and Br could have resulted from interplanetary processes, or from the superradial expansion of the coronal magnetic field close to the Sun, but find that neither possibility can produce the observed relationship. The derived heating relationship is consistent with (1) empirical heating laws derived for closed-field line regions and (2) theoretical models aimed at understanding both the heating and acceleration of the solar wind.

Affiliated with

Also associated with

No associations

Rating

On the relationship between coronal heating, magnetic flux, and the density of the solar wind does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with On the relationship between coronal heating, magnetic flux, and the density of the solar wind, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the relationship between coronal heating, magnetic flux, and the density of the solar wind will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1578068