Magnetic Helicity Generation by Solar Differential Rotation

By C. DeVore. 2000

213 citations recorded by the source corpus.

Subfields: Artificial Intelligence, Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/e770251d7580f7bc485b9bc189b0fb17afdb6f2a

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Citations in the corpus

The magnetic field in the solar atmosphere (2014, background): “In fact, a systematic study by LaBonte et al. (2007) on the helicity injection in ARs showed that all X-class flares were associated to peak helicity fluxes greater than 6 × 1036 Mx2 s−1 and consequently proposed a causal link of the peak helicity flux to the ability of an AR to produce an X-class f”
The Formation of a Prominence in Active Region NOAA 8668. I. SOHO/MDI Observations of Magnetic Field Evolution (2001, unknown): “This value is very close to the one predicted by DeVore (2000), (dH/dt)D \(n/32))F2 \ [1.0] 1040 Mx2 hr~1, with the use of )4 s~1 and F\ 1.0] 1022 Mx. Itdvrot/(R_ db) \[3 ] 10~7is an order of magnitude smaller than the contribution by the other shear Ñow.”
The Magnetic Helicity Budget of Solar Active Regions and Coronal Mass Ejections (2003, methodology): “The magnetic helicity per unit of length in an MC can be calculated if we know the axial magnetic field B0 and the radius R of the cloud’s flux rope (DeVore 2000; see his eq.”
Injection of Magnetic Energy and Magnetic Helicity into the Solar Atmosphere by an Emerging Magnetic Flux Tube (2003, background): “(18) will become the gauge-invariant relative magnetic helicity (Berger & Field 1984; Finn & Antonsen 1985) when the vector potential is given by (DeVore 2000) A (x , y , z , t) = AC (x , y , 0 , t)− ẑ × ∫ z 0 B ( x , y , z ′ , t ) dz ′ .”
The solar magnetic field (2006, background): “The ordered, differential rotation of the Sun is capable of generating only a small part of the helicity expected to reside in the closed coronal field [590] and seems insufficient to explain the total helicity flux which is eventually released in CMEs [510, 545].”
Magnetic Energy and Helicity Fluxes at the Photospheric Level (2003, background): “…the estimated number of CMEs leaving the volume V (defined by the coronal field extension of an AR magnetic field), assuming that the average magnetic helicity of a CME equates the average magnetic helicity found in magnetic clouds (see Rust & Kumar, 1996, DeVore, 2000, Démoulin et al., 2002).”
What is the source of the magnetic helicity shed by CMEs? The long-term helicity budget of AR 7978 (2002, methodology): “Following DeVore (2000), the length of the flux tube was estimated as ≈0.5 AU for clouds observed at 1 AU from the Sun.”
Astrophysical magnetic fields and nonlinear dynamo theory (2004, background): “The same sign distribution was also found by DeVore [45] who considered magnetic helicity generation by differential rotation.”
THE EMERGENCE OF A TWISTED FLUX TUBE INTO THE SOLAR ATMOSPHERE: SUNSPOT ROTATIONS AND THE FORMATION OF A CORONAL FLUX ROPE (2009, background): “It has also been shown (Berger and Field 1984; Devore 2000) that the rate of change of the relative helicity Hm can alternatively be computed by evaluating the helicity flux through the z = 0 boundary plane: dHm dt = −2 ∫ ∫ [(Ap · v)B− (Ap ·B)v] · ẑ dxdy (21) where Ap is given by equations…”
Observational Determination of the Rate of Magnetic Helicity Transport through the Solar Surface via the Horizontal Motion of Field Line Footpoints (2001, methodology): “They found a shear flow other than differential rotation that transported the magnetic helicity at a rate of Mx2 hr , which is also higher than the original40 16 # 10 DeVore (2000) estimate of Mx2 hr .40 11 # 10 3.”
Numerical Simulations of Three-dimensional Coronal Magnetic Fields Resulting from the Emergence of Twisted Magnetic Flux Tubes (2004, unknown): “Following DeVore (2000), we use the following specific A and Ap to compute Hm: A x; y; zð Þ ¼ Ap x; y; 0ð Þ ẑ Z z 0 B x; y; z0ð Þ dz0; ð12Þ Ap x; y; zð Þ ¼ : ẑ Z 1 z x; y; z0ð Þ dz0; ð13Þ where (x; y; z) ¼ 1 2 Z Z Bz x 0; y0; 0ð Þ x x0ð Þ2 þ y y0ð Þ2 þ z2 h i1=2 dx0 dy0: ð14Þ With the specific A…”
On the Magnetic Flux Budget in Low-Corona Magnetic Reconnection and Interplanetary Coronal Mass Ejections (2007, methodology): “In this study, we take L ¼ 1 AU, or calculate the poloidal flux per AU, while taking L ¼ 0:5 AU as the lower limit (e.g., DeVore 2000) and L ¼ 2 AU as the upper limit (e.g., Nindos et al. 2003).”