Issues with time-distance inversions for supergranular flows (Research Note)
Result description
Aims. Recent studies have shown that time-distance inversions for flows start to be dominated by a random noise at a depth of only a few Mm. It was proposed that the ensemble averaging might be a solution for learning about the structure of the convective flows, e.g. about the depth structure of supergranulation. Methods. Time-distance inversion is applied to the statistical sample of similar to 10(4) supergranules, which allows the inversion cost function to be regularised weakly about the random-noiseterm and thus provides a much better localisation in space. We compare these inversions at four depths (1.9, 2.9, 4.3, and 6.2 Mm) when using different spatio-temporal filtering schemes in order to gain confidence about these inferences. Results. The flows inferred by using different spatio-temporal filtering schemes are different (even by the sign) even though the formal averaging kernels and the random-noise levels are very similar. The inverted flows changes its sign several times wi
Keywords
The result's identifiers
Result code in IS VaVaI
Alternative codes found
RIV/67985815:_____/15:00450664
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Issues with time-distance inversions for supergranular flows (Research Note)
Original language description
Aims. Recent studies have shown that time-distance inversions for flows start to be dominated by a random noise at a depth of only a few Mm. It was proposed that the ensemble averaging might be a solution for learning about the structure of the convective flows, e.g. about the depth structure of supergranulation. Methods. Time-distance inversion is applied to the statistical sample of similar to 10(4) supergranules, which allows the inversion cost function to be regularised weakly about the random-noiseterm and thus provides a much better localisation in space. We compare these inversions at four depths (1.9, 2.9, 4.3, and 6.2 Mm) when using different spatio-temporal filtering schemes in order to gain confidence about these inferences. Results. The flows inferred by using different spatio-temporal filtering schemes are different (even by the sign) even though the formal averaging kernels and the random-noise levels are very similar. The inverted flows changes its sign several times wi
Czech name
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Czech description
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Classification
Type
Jx - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
BN - Astronomy and celestial mechanics, astrophysics
OECD FORD branch
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Result continuities
Project
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2015
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astronomy and Astrophysics [online]
ISSN
1432-0746
e-ISSN
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Volume of the periodical
575
Issue of the periodical within the volume
Neuveden
Country of publishing house
PL - POLAND
Number of pages
8
Pages from-to
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UT code for WoS article
000360710400023
EID of the result in the Scopus database
2-s2.0-84924709836
Result type
Jx - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP
BN - Astronomy and celestial mechanics, astrophysics
Year of implementation
2015