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Subsurface Flow Analysis

Description

  • Inputs: HMI tracked Dopplergrams of rectangular regions of solar disk.

  • Outputs: Travel-time difference maps for different skip distances and orientations; subsurface flow maps under the tracked region obtained by inversion; combinations of flow maps under tracked regions into synoptic maps.

  • Problem: Measure subsurface flows in upper convection zone, for use in understanding and predicting AR evolution and evolution of atmospheric magnetic structures.

Literature Search

Pre-processing, Cross-correlation and travel-time measurement
Title
Time-distance Measurements of Large Scale Flows in the Solar Convection Zone (Ph.D. Thesis)
Authour(s)
Peter M. Giles
URL
http://sun.stanford.edu/~giles/thesis/PDF/
Date Published
December 1999
Description
Detailed discussion of time-distance helioseismology with detailed description of data and filter used for pre-processing

Title
Time-distance Helioseismology: Noise Estimation
Authours
L. Gizon and A.C. Birch
Publication
The Astrophysical Journal, 614:472-489, 2004
URL
http://sun.stanford.edu/~gizon/PAPERS/apj_614_472.pdf
Date Published
2004 October 10
Description
robust definition of travel times

Forward problem, sensitivity kernels
Title
Time-distance Helioseismology: the forward problem for random distributed sources
Authours
L. Gizon and A.C. Birch
Publication
The Astrophysical Journal, 571:966-986, 2002
URL
http://sun.stanford.edu/~gizon/PAPERS/apj_571_966.pdf
Date Published
2002 June 1
Description
use of Born approximation for the forward problem

Title
Travel time sensitivity kernels
Authours
A.C.Birch and A.G.Kosovichev
Publication
Solar Physics, 192, 193-201 (2000)
URL
http://
Date Published
2000
Description
Travel time perturbation caused by a perturbation to sound speed is derived following the first Born approximation

Title
Sensitivity kernels for time-distance inversion based on the Rytov approximation
Authours
J.M. Jensen and F.P. Pijpers
Publication
Astronomy & Astrophysics, 412, 257-265 (2003)
URL
http://
Date Published
2003
Description
use of Rytov approximation for the forward problem

Inversion
Title
Multichannel Deconvolution, MCD, in Geophysics and Helioseismology
Authours
B.H. Jacobsen, I. Moller, J.M. Jensen and F.Efferso
Publication
Phys. Chen. Earth(A), Vol. 24, No. 3, 215-220
Date Published
1999
Description
Use of multi-channel deconvolution for the inversion of travel times

Title
Time-Distance Helioseismology of Subsurface Flows
Authours
Stephen J. Hughes and Michael J. Thompson
Publication
Proc. of SOHO 12/GONG+ 2002 'Local and Global Helioseismology: The Present and Future'
Date Published
2002
Description
Use of singular value decomposition for the inversion of travel times

Title
LSQR: An algorithm for sparse linear equations and sparse least squares
Authours
C. C. Paige and M. A. Saunders
Publication
ACM Transactions on Mathematical Software, Vol. 8, No. 1
URL
http://www.stanford.edu/group/SOL/software/lsqr/lsqr-toms82a.pdf
Date Published
March 1982
Description
Implementation of a conjugate-gradient type method for solving sparse linear equations and sparse least-squares problems.

Routines and Libraries

Test Data

  • SOHO/MDI tracked Doppler datacubes ?

Comments

-- ElizabethAuden - 11 Jan 2005

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Topic revision: r6 - 2005-05-23 - SergeiZharkov
 
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