Two Rotational Discontinuities in Collision: An Alternate Interpretation to the Suggestion of Widespread "Magnetic Reconnection" in the Solar Wind
Abstract
With a general non-dissipative model of two interacting rotational discontinuities (RDs) with opposing phase velocities along B we have reproduced the recently reported suite of signatures interpreted as those of collisionless magnetic reconnection in the solar wind. This model has been derived analytically and also reinforced with novel hybrid simulations of the interaction. Nearly a complete degeneracy is thus illustrated between the experimental evidence used to support the solar wind reconnection interpretation and the highly probable passing of two RDs through one another in the solar wind plasma that is often modeled as a "sea" of Alfvenic turbulence. The recovered morphology includes (i) the characteristic Walen signature with opposing signs, (ii) the Hall signatures, (iii) the ion phase space beams, (iv) the inferred "reconnection" rate from the non-zero tangential electric field and (v) counter-streaming jets. There is already evidence in the solar wind from B-V correlations that Alfvenic power is propagating in both directions relative to the radial and hence magnetic field direction. From this fact it is clear that the likelihood of the reconnection interpretation of the oppositely signed B-V correlations goes like the product of two probabilities P(a)P(b): P(a) for the inference that the shears are opposing RD layers and P(b) that assesses the probability that an unmeasured electron current scale layer enabling collisionless reconnection is attached to the observed MHD patterns. The present paper explains the observation only assuming that P(a) is a high likely in the Alfven turbulence already documented in the interplanetary medium. None of the presented evidence is compelling that P(b) is appreciable. Thus, by Occam's razor the two RD interaction (without attending reconnection) interpretation is the more likely interpretation of the space data, pending further differentiation of these two possibilities.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFMSM22A..05S
- Keywords:
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- 7811 Discontinuities (2109);
- 7827 Kinetic and MHD theory;
- 7835 Magnetic reconnection (2723;
- 7526)