Matches in SemOpenAlex for { <https://semopenalex.org/work/W2912504294> ?p ?o ?g. }
- W2912504294 endingPage "A51" @default.
- W2912504294 startingPage "A51" @default.
- W2912504294 abstract "Context . During solar minima the spatial power spectrum of the photospheric magnetic field is dominated by the low-degree zonal (axisymmetric; m = 0) harmonic components, reflecting the large polar coronal holes of unipolar magnetic field. However, measuring polar fields is difficult because of the unequal visibility of the two poles during most of the year and the small line-of-sight component of the roughly radial field at high solar latitudes. Aims . In this paper we derive the spatial power spectrum of the photospheric magnetic field in terms of the harmonic coefficients of the radial component ( B r ) as well as in terms of the harmonic coefficients of the internal potential (known as Gauss coefficients). We calculate the zonal spatial power spectrum using Mount Wilson Observatory synoptic maps from 1995–1996, during the solar minimum between solar cycles 22 and 23, and investigate how filling or not filling the polar data gaps affects the zonal harmonic coefficients. Methods . We eliminated the vantage point effect by removing the highest 5° of the measured magnetic field and calculating the latitudinal profile of the zonal median field over the two years, which ensured equal latitudinal data coverage of both solar hemispheres. We then derived the zonal harmonic coefficients using this latitudinal profile of B r . Results . We find that when the polar data gaps are left unfilled, a strong artificial power above l = 8 is produced. Only the first five zonal harmonic coefficients can be considered reliable in this case. Therefore polar filling is essential to obtain a realistic spatial power spectrum. Filling the polar gap with a constant (non-zero) value yields zonal harmonics that are reliable up to l = 9. We find that the zonal octupole component contributes most to the total spatial power, more than the zonal dipole, even during the solar minimum conditions. This difference is seen more clearly in the case of polar filling. We also prove that the asymmetry of the polar fields during this solar minimum is statistically significant. Conclusions . Our results emphasize the importance of filling the polar data gaps in order to obtain a correct estimate of the spatial power spectrum of the photospheric field. This helps in estimating the reliability of polar fields and the large-scale structure in synoptic maps of different origin. Our results also verify the asymmetric nature of the polar fields, which is important for the heliospheric magnetic field and for solar dynamo modeling." @default.
- W2912504294 created "2019-02-21" @default.
- W2912504294 creator A5005688995 @default.
- W2912504294 creator A5042801259 @default.
- W2912504294 creator A5052838510 @default.
- W2912504294 date "2019-03-01" @default.
- W2912504294 modified "2023-09-23" @default.
- W2912504294 title "Spatial power spectrum of the photospheric magnetic field during solar minimum" @default.
- W2912504294 cites W1912033148 @default.
- W2912504294 cites W1972034219 @default.
- W2912504294 cites W1974950197 @default.
- W2912504294 cites W1974990733 @default.
- W2912504294 cites W1975150072 @default.
- W2912504294 cites W2006534339 @default.
- W2912504294 cites W2012007653 @default.
- W2912504294 cites W2015545843 @default.
- W2912504294 cites W2024464413 @default.
- W2912504294 cites W2042553415 @default.
- W2912504294 cites W2043115504 @default.
- W2912504294 cites W2050696886 @default.
- W2912504294 cites W2055935013 @default.
- W2912504294 cites W2060688994 @default.
- W2912504294 cites W2068146077 @default.
- W2912504294 cites W2083082362 @default.
- W2912504294 cites W2119050415 @default.
- W2912504294 cites W2346852432 @default.
- W2912504294 cites W3100859206 @default.
- W2912504294 cites W3102039086 @default.
- W2912504294 doi "https://doi.org/10.1051/0004-6361/201834216" @default.
- W2912504294 hasPublicationYear "2019" @default.
- W2912504294 type Work @default.
- W2912504294 sameAs 2912504294 @default.
- W2912504294 citedByCount "3" @default.
- W2912504294 countsByYear W29125042942020 @default.
- W2912504294 countsByYear W29125042942021 @default.
- W2912504294 countsByYear W29125042942023 @default.
- W2912504294 crossrefType "journal-article" @default.
- W2912504294 hasAuthorship W2912504294A5005688995 @default.
- W2912504294 hasAuthorship W2912504294A5042801259 @default.
- W2912504294 hasAuthorship W2912504294A5052838510 @default.
- W2912504294 hasBestOaLocation W29125042941 @default.
- W2912504294 hasConcept C102988692 @default.
- W2912504294 hasConcept C108411613 @default.
- W2912504294 hasConcept C115260700 @default.
- W2912504294 hasConcept C121332964 @default.
- W2912504294 hasConcept C127313418 @default.
- W2912504294 hasConcept C1276947 @default.
- W2912504294 hasConcept C146138569 @default.
- W2912504294 hasConcept C151730666 @default.
- W2912504294 hasConcept C171428510 @default.
- W2912504294 hasConcept C188841122 @default.
- W2912504294 hasConcept C202444582 @default.
- W2912504294 hasConcept C2779343474 @default.
- W2912504294 hasConcept C29705727 @default.
- W2912504294 hasConcept C30475298 @default.
- W2912504294 hasConcept C33923547 @default.
- W2912504294 hasConcept C3768446 @default.
- W2912504294 hasConcept C43867161 @default.
- W2912504294 hasConcept C44870925 @default.
- W2912504294 hasConcept C62520636 @default.
- W2912504294 hasConcept C64162976 @default.
- W2912504294 hasConcept C72886185 @default.
- W2912504294 hasConcept C9652623 @default.
- W2912504294 hasConceptScore W2912504294C102988692 @default.
- W2912504294 hasConceptScore W2912504294C108411613 @default.
- W2912504294 hasConceptScore W2912504294C115260700 @default.
- W2912504294 hasConceptScore W2912504294C121332964 @default.
- W2912504294 hasConceptScore W2912504294C127313418 @default.
- W2912504294 hasConceptScore W2912504294C1276947 @default.
- W2912504294 hasConceptScore W2912504294C146138569 @default.
- W2912504294 hasConceptScore W2912504294C151730666 @default.
- W2912504294 hasConceptScore W2912504294C171428510 @default.
- W2912504294 hasConceptScore W2912504294C188841122 @default.
- W2912504294 hasConceptScore W2912504294C202444582 @default.
- W2912504294 hasConceptScore W2912504294C2779343474 @default.
- W2912504294 hasConceptScore W2912504294C29705727 @default.
- W2912504294 hasConceptScore W2912504294C30475298 @default.
- W2912504294 hasConceptScore W2912504294C33923547 @default.
- W2912504294 hasConceptScore W2912504294C3768446 @default.
- W2912504294 hasConceptScore W2912504294C43867161 @default.
- W2912504294 hasConceptScore W2912504294C44870925 @default.
- W2912504294 hasConceptScore W2912504294C62520636 @default.
- W2912504294 hasConceptScore W2912504294C64162976 @default.
- W2912504294 hasConceptScore W2912504294C72886185 @default.
- W2912504294 hasConceptScore W2912504294C9652623 @default.
- W2912504294 hasLocation W29125042941 @default.
- W2912504294 hasLocation W29125042942 @default.
- W2912504294 hasLocation W29125042943 @default.
- W2912504294 hasOpenAccess W2912504294 @default.
- W2912504294 hasPrimaryLocation W29125042941 @default.
- W2912504294 hasRelatedWork W1990729680 @default.
- W2912504294 hasRelatedWork W2012989918 @default.
- W2912504294 hasRelatedWork W2014003661 @default.
- W2912504294 hasRelatedWork W2039037067 @default.
- W2912504294 hasRelatedWork W2121451777 @default.
- W2912504294 hasRelatedWork W2795092587 @default.
- W2912504294 hasRelatedWork W2912504294 @default.
- W2912504294 hasRelatedWork W3138560165 @default.