Magnetic cloud fit by uniform-twist toroidal flux ropes
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F17%3A00484734" target="_blank" >RIV/67985815:_____/17:00484734 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1051/0004-6361/201731412" target="_blank" >http://dx.doi.org/10.1051/0004-6361/201731412</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1051/0004-6361/201731412" target="_blank" >10.1051/0004-6361/201731412</a>
Alternative languages
Result language
angličtina
Original language name
Magnetic cloud fit by uniform-twist toroidal flux ropes
Original language description
Magnetic clouds are bent, and for some observations, a toroidal rather than a cylindrical flux rope is needed for a local approximation of the cloud fields. We therefore try to derive an axially symmetric uniform-twist force-free field in a toroid, either exactly, or approximately, and to compare it with observations. Equations following from the conditions of solenoidality and force-freeness in toroidally curved cylindrical coordinates were solved analytically. The magnetic field and velocity observations of a magnetic cloud were compared with solutions obtained using a nonlinear least-squares method. Three solutions of (nearly) uniform-twist magnetic fields in a toroid were obtained. All are exactly solenoidal, and in the limit of high aspect ratios, they tend to the Gold-Hoyle field. The first solution has an exactly uniform twist, the other two solutions have a nearly uniform twist and approximate force-free fields. The analysis of a magnetic cloud observation showed that these fields may fit the observed field equally well as the already known approximately linear force-free (Miller-Turner) field, but it also revealed that the geometric parameters of the toroid might not be reliably determined from fits, when (nearly) uniform-twist model fields are used. Sets of parameters largely differing in the size of the toroid and its aspect ratio yield fits of a comparable quality.n
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
<a href="/en/project/GA17-06065S" target="_blank" >GA17-06065S: Solar wind variations and their impact on magnetospheric dynamics</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astronomy & Astrophysics
ISSN
1432-0746
e-ISSN
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Volume of the periodical
608
Issue of the periodical within the volume
December
Country of publishing house
FR - FRANCE
Number of pages
12
Pages from-to
"A118/1"-"A118/12"
UT code for WoS article
000418458600012
EID of the result in the Scopus database
2-s2.0-85038411817