2024-09-24T22:22:03.000Z http://sot.lmsal.com Mr. Sam Freeland Lockheed Martin Solar and Astrophysics Laboratory (LMSAL) http://www.lmsal.com Lockheed Martin Advanced Tech Center, 3251 Hanover Rd, O/ADBS, B/252, Palo Alto, CA 94304 null null HINODE SOTSP Hosoi Iwai Zoe (RCO) 315 HOP315 (AR flows and fields) Active Region AR AR 12597 7 20160924_164706 279 311 320 7 60 400 2 1 1 2 0 52 2025 197 0.985 159.658 -361.597 62.449 121.728 2016-09-24T16:47:06.000Z 2016-09-24T16:59:43.000Z 159.658 -361.597 Short-term Active Region Evolution Fast map 64x122", 1-side, Q75 The flow and magnetic fields surrounding an active region (AR) filament play an important role in filament formation, their evolution and disruption. AR filament eruptions are often related to coronal mass ejections (CMEs) (e.g., Low et al. 2001, JGR 106, 25141; Gopalswamy et al. 2003, ApJ 286, 562). CMEs are the most energetic events in the solar system expelling up to 10 13 kg of coronal material from the Sun at speeds of several hundreds to thousands of kilometers per second. Since AR filaments and CMEs are closely connected and the primary cause of space weather disturbances, we need to understand their properties, especially their ultimate origin, precursors, and near-Sun evolution in order to predict them. Filaments are embedded in magnetic fields. Their plasma is sustained against gravity by magnetic field lines. There are several models which aim to explain this phenomenon. The sheared arcade models show sheared field lines below an unsheared coronal arcade (Antiochos et al. 1994, APJL 420, 41) where plasma can be stored. Eventually, reconnection can happen between the sheared and overlying unsheared field lines producing helical field lines (DeVore and Antiochos 2000, APJ 539, 954-963) which are typically called flux ropes. The well-know flux-rope model from van Ballegooijen and Martens (1989, APJ 343, 971-984) attempts to explain how these helical structures are formed in the chromosphere or corona when combining photospheric converging flows and shearing motions at the magnetic neutral line producing reconnection processes. So far, there are only few observations of active region filaments to support the aforementioned models (e.g., Okamoto et al. 2008, APJ 673, L215-L218; Lites et al. 2010, APJ 718, 474-487; Kuckein et al. 2012, AandA 539, A131; Kuckein et al. 2012, AandA 542, A112; Xu et al. 2012, APJ 749, 138). Furthermore, such a study requires simultaneous and coordinated observations of several layers of the Sun, including spectropolarimetry. Improved measurements of the photospheric and chromospheric three-dimensional magnetic and flow fields are crucial for a precise determination of the origin and evolution of AR filaments. We will carry out such measurements based on high-resolution vector magnetograms and three-dimensional flow field observations. Transverse flow field measurements will be based on speckle reconstructed intensity images. This provides a more realistic approximation of the real plasma velocity fields rather than velocity measurements derived from longitudinal magnetograms. Combining photospheric and chromospheric vector magnetograms (e.g., Yelles Chaouche et al. 2012, APJ 748, 23) will make it possible to understand how AR filaments are formed and how they eventually evolve towards a CME.;;The flow and magnetic fields surrounding an active region (AR) filament play an important role in filament formation, their evolution and disruption. AR filament eruptions are often related to coronal mass ejections (CMEs) (e.g., Low et al. 2001, JGR 106, 25141; Gopalswamy et al. 2003, ApJ 286, 562). CMEs are the most energetic events in the solar system expelling up to 10 13 kg of coronal material from the Sun at speeds of several hundreds to thousands of kilometers per second. Since AR filaments and CMEs are closely connected and the primary cause of space weather disturbances, we need to understand their properties, especially their ultimate origin, precursors, and near-Sun evolution in order to predict them. Filaments are embedded in magnetic fields. Their plasma is sustained against gravity by magnetic field lines. There are several models which aim to explain this phenomenon. The sheared arcade models show sheared field lines below an unsheared coronal arcade (Antiochos et al. 1994, APJL 420, 41) where plasma can be stored. Eventually, reconnection can happen between the sheared and overlying unsheared field lines producing helical field lines (DeVore and Antiochos 2000, APJ 539, 954-963) which are typically called flux ropes. The well-know flux-rope model from van Ballegooijen and Martens (1989, APJ 343, 971-984) attempts to explain how these helical structures are formed in the chromosphere or corona when combining photospheric converging flows and shearing motions at the magnetic neutral line producing reconnection processes. So far, there are only few observations of active region filaments to support the aforementioned models (e.g., Okamoto et al. 2008, APJ 673, L215-L218; Lites et al. 2010, APJ 718, 474-487; Kuckein et al. 2012, AandA 539, A131; Kuckein et al. 2012, AandA 542, A112; Xu et al. 2012, APJ 749, 138). Furthermore, such a study requires simultaneous and coordinated observations of several layers of the Sun, including spectropolarimetry. Improved measurements of the photospheric and chromospheric three-dimensional magnetic and flow fields are crucial for a precise determination of the origin and evolution of AR filaments. We will carry out such measurements based on high-resolution vector magnetograms and three-dimensional flow field observations. Transverse flow field measurements will be based on speckle reconstructed intensity images. This provides a more realistic approximation of the real plasma velocity fields rather than velocity measurements derived from longitudinal magnetograms. Combining photospheric and chromospheric vector magnetograms (e.g., Yelles Chaouche et al. 2012, APJ 748, 23) will make it possible to understand how AR filaments are formed and how they eventually evolve towards a CME. ivo://sot.lmsal.com/VOEvent#2016-09-24T16:47:00Z