Radial Distributions of Coronal Electron Temperatures: Specificities of the DYN Model
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Authors
Lemaire, J.F.
Katsiyannis, A.C.
Discipline
Physical sciences
Subject
Corona
Inner corona, models
Solar wind
Solar wind, theory
Electron density
Electron temperature
Coronal heating
Velocity fields, solar wind
Audience
Scientific
Date
2021Metadata
Show full item recordDescription
This paper is a follow up of the article where Lemaire and Stegen (Solar Phys. 291(12), 3659, 2016) introduced their DYN method to calculate coronal temperature profiles from given radial distributions of the coronal and solar wind (SW) electron densities. Several such temperature profiles are calculated and presented corresponding to a set of given empirical density models derived from eclipse observations and in-situ measurements of the electron density and bulk velocity at 1 AU. The DYN temperature profiles obtained for the equatorial and polar regions of the corona challenge the results deduced since 1958 from singular hydrodynamical models of the SW. In these models—where the expansion velocity transits through a singular saddle point—the maximum coronal temperature is predicted to be located at the base of the corona, while in all DYN models the altitude of the maximum temperature is found at significantly higher altitudes in the mid-corona. Furthermore, the maximum of the DYN-estimated temperatures is found at much higher altitudes over the polar regions and coronal holes, than over the equator. However, at low altitudes, in the inner corona, the DYN temperatures are always smaller at high latitudes, than at low equatorial latitudes. This appears well in agreement with existing coronal hole observations. These findings have serious implications on the open questions: what is the actual source of the coronal heating, and where is the maximum energy deposited within the solar corona?
Citation
Lemaire, J.F.; Katsiyannis, A.C. (2021). Radial Distributions of Coronal Electron Temperatures: Specificities of the DYN Model. , Solar Physics, Vol. 296, Issue 4, A64, DOI: 10.1007/s11207-021-01814-4.Identifiers
Type
Article
Peer-Review
Yes
Language
eng