| タイトル | Systematic Center-To-Limb Variation in Measured Helioseismic Travel Times and Its Effect on Inferences of Solar Interior Meridional Flows |
| 本文（外部サイト） | http://hdl.handle.net/2060/20140010271 |
| 著者（英） | Bogart, R. S.; Kosovichev, Alexander; Zhao, Junwei; Duvall, T. L., Jr.; Nagashima, Kaori |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2012-03-20 |
| 言語 | eng |
| 内容記述 | We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s1 slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood. |
| NASA分類 | Solar Physics |
| レポートNO | GSFC-E-DAA-TN9960 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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