The anisotropy of kinetic and current helicity

2017 ◽  
Vol 61 (9) ◽  
pp. 783-790 ◽  
Author(s):  
M. Yu. Reshetnyak
Keyword(s):  
Current Helicity

Alpha-Effect, Current and Kinetic Helicities for Magnetically Driven Turbulence, and Solar Dynamo

2000 ◽  
Vol 179 ◽  
pp. 387-388
Author(s):  
Gaetano Belvedere ◽  
V. V. Pipin ◽  
G. Rüdiger
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Convection Zone ◽  
Solar Surface ◽  
Momentum Transport ◽  
Angular Momentum Transport ◽  
Magnetic Buoyancy ◽  
Alpha Effect ◽  
Current Helicity

Extended AbstractRecent numerical simulations lead to the result that turbulence is much more magnetically driven than believed. In particular the role ofmagnetic buoyancyappears quite important for the generation ofα-effect and angular momentum transport (Brandenburg & Schmitt 1998). We present results obtained for a turbulence field driven by a (given) Lorentz force in a non-stratified but rotating convection zone. The main result confirms the numerical findings of Brandenburg & Schmitt that in the northern hemisphere theα-effect and the kinetic helicityℋkin= 〈u′ · rotu′〉 are positive (and negative in the northern hemisphere), this being just opposite to what occurs for the current helicityℋcurr= 〈j′ ·B′〉, which is negative in the northern hemisphere (and positive in the southern hemisphere). There has been an increasing number of papers presenting observations of current helicity at the solar surface, all showing that it isnegativein the northern hemisphere and positive in the southern hemisphere (see Rüdigeret al. 2000, also for a review).

The Hemispheric Sign Rule of Current Helicity during the Rising Phase of Cycle 23

2000 ◽  
Vol 179 ◽  
pp. 303-306
Author(s):  
S. D. Bao ◽  
G. X. Ai ◽  
H. Q. Zhang
Keyword(s):  
Solar Cycle ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Active Regions ◽  
Hemispheric Preference ◽  
Current Helicity

AbstractWe compute the signs of two different current helicity parameters (i.e., αbestandHc) for 87 active regions during the rise of cycle 23. The results indicate that 59% of the active regions in the northern hemisphere have negative αbestand 65% in the southern hemisphere have positive. This is consistent with that of the cycle 22. However, the helicity parameterHcshows a weaker opposite hemispheric preference in the new solar cycle. Possible reasons are discussed.

scholarly journals Intermittency spectra of current helicity in solar active regions

2018 ◽  
Vol 480 (3) ◽  
pp. 3780-3787 ◽  
Author(s):  
A S Kutsenko ◽  
V I Abramenko ◽  
K M Kuzanyan ◽  
Haiqing Xu ◽  
Hongqi Zhang
Keyword(s):  
Active Regions ◽  
Solar Active Regions ◽  
Current Helicity

scholarly journals A survey of flares and current helicity in active regions

1999 ◽  
Vol 139 (2) ◽  
pp. 311-320 ◽  
Author(s):  
S. D. Bao ◽  
H. Q. Zhang ◽  
G. X. Ai ◽  
M. Zhang
Keyword(s):  
Active Regions ◽  
Current Helicity

The Alpha Effect and the Observed Twist and Current Helicity of Solar Magnetic Fields

Solar Physics ◽  
2006 ◽  
Vol 233 (2) ◽  
pp. 185-204 ◽  
Author(s):  
K. M. Kuzanyan ◽  
V. V. Pipin ◽  
N. Seehafer
Keyword(s):  
Magnetic Fields ◽  
Solar Magnetic Fields ◽  
Alpha Effect ◽  
Current Helicity

Electric current helicity in the solar atmosphere

Solar Physics ◽  
1990 ◽  
Vol 125 (2) ◽  
pp. 219-232 ◽  
Author(s):  
N. Seehafer
Keyword(s):  
Electric Current ◽  
Solar Atmosphere ◽  
Current Helicity
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