Skip to main content

Sensitivity Kernels for Inferring Lorentz Stresses from Normal-mode Frequency Splittings in the Sun

Author(s): Das, Srijan Bharati; Chakraborty, Tuneer; Hanasoge, Shravan M; Tromp, Jeroen

To refer to this page use:
Full metadata record
DC FieldValueLanguage
dc.contributor.authorDas, Srijan Bharati-
dc.contributor.authorChakraborty, Tuneer-
dc.contributor.authorHanasoge, Shravan M-
dc.contributor.authorTromp, Jeroen-
dc.identifier.citationDas, Srijan Bharati, Tuneer Chakraborty, Shravan M. Hanasoge, and Jeroen Tromp. "Sensitivity kernels for inferring Lorentz stresses from normal-mode frequency splittings in the Sun." The Astrophysical Journal 897, no. 1 (2020). doi:10.3847/1538-4357/ab8e3a.en_US
dc.description.abstractDepartures from standard spherically symmetric solar models, in the form of perturbations such as global and local-scale flows and structural asphericities, result in the splitting of eigenfrequencies in the observed spectrum of solar oscillations. Drawing from prevalent ideas in normal-mode-coupling theory in geophysical literature, we devise a procedure that enables the computation of sensitivity kernels for general Lorentz-stress fields in the Sun. Mode coupling due to any perturbation requires careful consideration of self- and cross coupling of multiplets. Invoking the isolated-multiplet approximation allows for limiting the treatment to purely self coupling, requiring significantly less computational resources. We identify the presence of such isolated multiplets under the effect of Lorentz stresses in the Sun. Currently, solar missions allow for precise measurements of self coupling of multiplets via "a-coefficients" and the cross-spectral correlation signal that enables the estimation of the "structure coefficients". We demonstrate the forward problem for both self coupling (a-coefficients) and cross coupling (structure coefficients). In doing so, we plot the self-coupling kernels and estimate a-coefficients arising from a combination of deep-toroidal and surface-dipolar axisymmetric fields. We also compute the structure coefficients for an arbitrary general magnetic field (real and solenoidal) and plot the corresponding "splitting function", a convenient way to visualize the splitting of multiplets under 3D internal perturbations. The results discussed in this paper pave the way to formally pose an inverse problem and infer solar internal magnetic fields.en_US
dc.relation.ispartofThe Astrophysical Journalen_US
dc.rightsAuthor's manuscripten_US
dc.titleSensitivity Kernels for Inferring Lorentz Stresses from Normal-mode Frequency Splittings in the Sunen_US
dc.typeJournal Articleen_US

Files in This Item:
File Description SizeFormat 
Sensitivity_Kernels_Inferring_Lorentz_Stresses_Normal-mode_Frequency_Splittings_Sun.pdf14.41 MBAdobe PDFView/Download

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.