Comparison of time-distance inversion methods applied to SDO/HMI Dopplergrams

0511456 - ASÚ 2020 RIV FR eng J - Journal Article
Korda, D. - Švanda, Michal - Zhao, J.
Comparison of time-distance inversion methods applied to SDO/HMI Dopplergrams.
Astronomy & Astrophysics. Roč. 629, September (2019), č. článku A55. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR(CZ) GA18-06319S
Institutional support: RVO:67985815
Keywords : Sun * helioseismology * oscillations
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.636, year: 2019
Method of publishing: Limited access
https://doi.org/10.1051/0004-6361/201936268

We compared the results from the JSOC pipeline for horizontal flow components and the perturbations of the speed of sound at set of depths with equivalent results from an independently implemented pipeline using a different time-distance inversion scheme. Our inversion pipeline allows inversion for all quantities at once while allowing minimisation of the crosstalk between them. This gives us an opportunity to discuss the possible biases present in the JSOC data products. We successfully reproduced the horizontal flow components. The sound-speed perturbations are strongly affected by the high level of the cross-talk in JSOC products. This leads to larger amplitudes in the inversions for the sound-speed perturbations. Different results were obtained when a target function localised around the target depth was used. This is a consequence of non-localised JSOC averaging kernels. We add that our methodology also allows inversion for the vertical flow.
Permanent Link: http://hdl.handle.net/11104/0301723