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Seething Horizontal Magnetic Fields in the Quiet Solar Photosphere

Seething Horizontal Magnetic Fields in the Quiet Solar Photosphere. J. Harvey, D. Branston, C. Henney, C. Keller, SOLIS and GONG Teams. Internetwork Field (pre- Hinode ). Photosphere. Chromosphere. Observed since 1971 (these images from 1975). IN Field Properties (pre- Hinode ).

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Seething Horizontal Magnetic Fields in the Quiet Solar Photosphere

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  1. Seething Horizontal Magnetic Fields in the Quiet Solar Photosphere J. Harvey, D. Branston, C. Henney, C. Keller, SOLIS and GONG Teams

  2. Internetwork Field (pre-Hinode) Photosphere Chromosphere Observed since 1971 (these images from 1975)

  3. IN Field Properties (pre-Hinode) • Arc sec sizes • Fluxes ~1016 Mx • Lifetimes ~hour • Mixed polarities • Orientations uncertain • Move with supergranular flow • True field strengths controversial • Weak in chromosphere

  4. New LOS Magnetograms SOLIS GONG

  5. LOS Field Movie Near limb Disk center Weak network Strong seething Limb seeing Mottles Mixed polarity Strong network Weak seething Slow evolution Points Mixed polarity GONG Big Bear, 10.5 hr, 2007 April 27, ±20 G range, 10 min cadence

  6. Seething Signal Increases Toward Limb • 7 hour RMS • Display range 1.3 – 2.3 G • No variation with disk position other than radial • Orientation must be nearly horizontal

  7. Radial Average of Seething Signal RMS • Noise- corrected RMS fit by field inclined at 74° • ~1.4 G near limb (1.7 G from higher resolution SOLIS data) observed noise model fit noise corrected

  8. Average Temporal Power Spectra • Near limbs, ν-1.4 power law variation • No 5-min or other oscillation • More complicated near center • Hard to interpret physically ν-1.4 near limb near disk center Log

  9. Seething Field in Chromosphere • No center-limb variation of seething field -> • No preferred orientation Disk center Near limb SOLIS VSM, 3 hr, 2007 April 18, ±20 G range, 5 min cadence, core of 8542 Å

  10. Results • Ubiquitous nearly horizontal field • Spatially patchy up to ~15” size • Non-periodic time variations minutes to hours • RMS near limb >1.7 G • No large-scale spatial variation • Total amount of flux ~3 x 1022 Mx • Weaker in chromosphere, no preferred orientation

  11. Conclusions • Could be dynamic, low-lying loops connecting network and IN flux elements? (But, no dependence on large-scale flux patterns) • Time and space scales suggest local creation and driving by granular and supergranular convection (See ApJL April 20, 2007 Vol. 659, p. L177)

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