On the thermal conductivity of the quiet solar-wind plasma and consequences

view Abstract Citations (18) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Thermal Conductivity of the Quiet Solar-Wind Plasma and Consequences Cuperman, S. ; Metzler, N. Abstract The structure, space dependence and consequences of an anomalously low (electron) thermal conductivity in the quiet solar wind are investigated. The solar wind is described by fluid equations but the thermal conductivity includes effects coming from both the inhibition of heat transport across the spiraling interplanetary magnetic field and electromagnetic turbulence (noncollisional processes). The main results of the investigation are: i) The temperature (T) and heat flux (H = - kdTldr) through 1 a.u. depend mainly on the relative importance of the transport of energy by conduction at low heliocentric distances (below 3040 R0), and at larger heliocentric distances (beyond 3040 R0). ii) If a significant reduction in the transport of energy by conduction occurs only at distances larger than about 3040 R0, then the solutions of the equations predict T and H values at 1 a.u. which are larger than those corresponding to a pure collisional, uninhibited thermal conductivity. This is the case, for instance, when only inhibition of heat transport across the spiraling interplanetary magnetic field [a cos2 (r) reduction factor] is considered. iii) A sharp reduction of the thermal conduction mainly at low heliocentric distances, presumably due to wave-particle interactions and inhibition across the partially closed, looplike magnetic configurations at the base of the corona, provides satisfactory solutions for T and H (and n, v) through 1 a.u. Use of the reduction factor, cos2 4i(r), to account for the inhibition across the spiraling interplanetary magnetic field predicts satisfactory T and H solutions only if exactly the same sharp reduction factor exists at low heliocentric distances as before. This indicates the essential result, namely, the importance of the reduction of the thermal conductivity at mainly low heliocentric distances; this kind of reduction is necessary to reproduce the actual state of the quiet solar wind. The paper is supplemented by a physical discussion of the problem. Subject headings: hydromagnetics - plasmas - solar wind Publication: The Astrophysical Journal Pub Date: June 1973 DOI: 10.1086/152196 Bibcode: 1973ApJ...182..961C full text sources ADS |