Investigation of Thickness and Electrical Resistivity of the Current Sheets in Solar Eruptions

Lin, Jin‐Ming; Li, J.; Ko, Yuan‐Kuen; Raymond, J. C.

doi:10.1088/0004-637x/693/2/1666

Cited by 63 publications

(91 citation statements)

References 44 publications

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“…So UVCS is observing the reconnection region, though much of the emitting gas might not be heated at the position observed, but somewhere between this position and the X-line. As we mentioned earlier in this work as well as in our previous work (e.g., see Lin et al 2009), the reconnection region discussed here is, in fact, the CS in a more general sense.…”

Section: Identifications Of the Current Sheet In The Solar Eruptive Esupporting

confidence: 74%

“…In this approach, the intensity distribution of the current sheet along the strip is first displayed, and then the apparent value of d is determined by the FWHM of the Gaussian profile used to fit the observational distribution. Lin et al (2009) found that analyzing the LASCO data by LSMs still brought the apparent value of d to the range from 10 4 to 10 5 km.…”

Section: Observed Apparent Thickness Of Current Sheetsmentioning

confidence: 97%

“…The CS is also often observed by LASCO on SOHO, studying the LASCO white-light images may also reveal the information of apparent d. In addition to analyzing the UVCS data, Lin et al (2009) also investigated the size of the current sheet developed in the above two events via studying the LASCO/C2 and C3 data by an approach known as limb synoptic maps (LSMs; Li et al 2000). An LSM is made by extracting a strip around the solar limb at a fixed altitude from an image, and then aligning the strips in time sequences.…”

Section: Observed Apparent Thickness Of Current Sheetsmentioning

confidence: 99%

“…As a result of the modest EM of the current sheets in eruptive events compared to that of the nearby corona, on the other hand, the current sheet may be faint and difficult to detect if it is not observed roughly edge-on. Below, we discuss how projection effects impact measurements of d (see also Lin et al 2009). …”

Section: Impact Of Projection Effects On Apparent Values Of Dmentioning

confidence: 99%

“…Different mechanisms could give rise to the same output. For example, Sweet-Parker CS with anomalous resistivity Biskamp 2000;Priest and Forbes 2000), Petschek-type reconnection (Petschek 1964;Biskamp 1986;Forbes and Priest 1987;Yokoyama and Shibata 1994;Kulsrud 2001;Drake et al 2006;Baty et al 2009;Vršnak et al 2009;Zweibel and Yamada 2009;Ko et al 2010;Liu et al 2012), and turbulent reconnection (Strauss 1988;Bhattacharjee and Yuan 1995;Lazarian and Vishniac 1999;Lin et al 2007Lin et al , 2009Lazarian et al , 2014. These different dissipation styles may even work together to yield a much more complex pattern and more efficient diffusion than that dominated only by a single mechanism (e.g., see also Mei et al 2012).…”

Section: Introductionmentioning

confidence: 99%

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Review on Current Sheets in CME Development: Theories and Observations

et al. 2015

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We introduce how the catastrophe model for solar eruptions predicted the formation and development of the long current sheet (CS) and how the observations were used to recognize the CS at the place where the CS is presumably located. Then, we discuss the direct measurement of the CS region thickness by studying the brightness distribution of the CS region at different wavelengths. The thickness ranges from 10 4 km to about 10 5 km at heights between 0.27 and 1.16 R from the solar surface. But the traditional theory indicates that the CS is as thin as the proton Larmor radius, which is of order tens of meters in the corona. We look into the huge difference in the thickness between observations and theoretical expectations. The possible impacts that affect measurements and results are studied, and physical causes leading to a thick CS region in which reconnection can still occur at a reasonably fast rate are analyzed. Studies in both theories and observations suggest that the difference between the true value and the apparent value of the CS thickness is not significant as long as the CS could be recognised in observations. We review observations that show complex structures and flows inside the CS region and present recent numerical modelling results on some aspects of these structures. Both observations and numerical experiments indicate that the downward reconnection outflows are usually slower than the upward ones in the same eruptive event. Numerical simulations show that the complex structure inside CS and its temporal behavior as a result of turbulence and the Petschek-type slow-mode shock could probably account for the thick CS and fast reconnection. But whether the CS itself is that thick still remains unknown since, for the time being, we cannot measure the electric current directly in that region. We also review the most recent laboratory experiments of reconnection driven by energetic laser beams, and discuss some important topics for future works.

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Section: Identifications Of the Current Sheet In The Solar Eruptive Esupporting

confidence: 74%

Section: Observed Apparent Thickness Of Current Sheetsmentioning

confidence: 97%