New Year’s Comet

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New Year’s Comet

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New Year’s Comet. Evolution of Magnetic Fields in Convection Zone. Study of the evolution of magnetic fields in the convection zone over cycle 23 from SOHO/MDI oscillation measurements Poloidal field + double-peaked near-surface toroidal field Poloidal : 124 ± 16 G - PowerPoint PPT Presentation

Transcript of New Year’s Comet

Page 1: New Year’s Comet

New Year’s Comet

Page 2: New Year’s Comet

Evolution of Magnetic Fields in Convection Zone

• Study of the evolution of magnetic fields in the convection zone over cycle 23 from SOHO/MDI oscillation measurements

• Poloidal field + double-peaked near-surface toroidal field– Poloidal: 124 ± 16 G

– Toroidal: 380 ± 30 @ 0.999 R 1.4

± 0.2 kG @ 0.996 R

• Field strengths highly correlated with surface activity

Baldner et al.: 2009, ApJ 705, 1704

Page 3: New Year’s Comet

Quasi-periodic Oscillations in LASCO CME Speeds

• Analysis of the speed-distance profiles of a sample of 116 CMEs

• 15 cases show quasi-periodic oscillations with periods from 48 to 240 min

• Oscillations interpreted as normal modes of 3D flux ropes

Shanmugaraji et al.: 2010, ApJ 708, 450

Page 4: New Year’s Comet

The Nascent Fast Solar Wind Observed in the Corona by Hinode/EIS

• Origin of fast solar wind one of the most important unresolved problems in space and solar physics

• Deep exposures in corona hole with EIS reveals first spectroscopic signatures of nascent fast solar wind at coronal temperatures (T > 1 MK)

• Outflows become stronger with increasing temperature

• Isolated outflow patches in transition region merge in corona, in agreement with scenario of solar wind outflow being guided by expanding magnetic funnels

Tian et al.: 2010, ApJ 709, L88

Temperature / MK0.63 1 1.3 1.8

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