Time_distance inversions for horizontal and vertical flows on supergranular scales applied to MDI and HMI data

Eclipse on the Coral Sea: Cycle 24 Ascending

物理学;天文学

Švanda, M.^1,2 ; Schunker, H.^3 ; Burston, R.^3

Astronomical Institute, Academy of Sciences of the Czech Republic (V. V. I.), Friova 298, CZ-25165 Ondejov, Czech Republic^1

Charles University in Prague, Faculty of Mathematics and Physics, Astronomical Institute, V Holeovikách 2, CZ-18000 Prague 8, Czech Republic^2

Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau, Germany^3

关键词: Doppler signals;    Dopplergrams;    Highly-correlated;    Near-surface layers;    Spatial power spectrums;    Three component;    Time distance;    Vertical flows;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/440/1/012024/pdf
DOI  :  10.1088/1742-6596/440/1/012024

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

We study the possibility of consistent extension of MDI full-disc helioseismic campaigns with the growing data set of HMI observations. To do so, we down-sample and filter the HMI Dopplegrams so that the resulting spatial power spectrum is similar to the spatial power spectrum of MDI full-disc Dopplergrams. The set of co-spatial and co-temporal datacube pairs from both instruments containing no missing and no bad frames were processed using the same codes and inverted independently for all three components of the plasma flow in the near surface layers. The results from the two instruments are highly correlated, however systematically larger (by ∼ 20%) flow magnitudes are derived from HMI. We comment that this may be an effect of the different formation depth of the Doppler signal from the two instruments.