The average tilt angle of sunspot groups emerging throughout the solar cycle
determines the net magnetic flux crossing the equator, which is correlated with
the strength of the subsequent cycle. I suggest that a deep-seated, non-local
process can account for the observed cycle-dependent changes in the average
tilt angle. Motivated by helioseismic observations indicating cycle-scale
variations in the sound speed near the base of the convection zone, I
determined the effect of a thermally perturbed overshoot region on the
stability of flux tubes and on the tilt angles of emerging flux loops. I found
that 5-20 K of cooling is sufficient for emerging flux loops to reproduce the
reported amplitude of cycle-averaged tilt angle variations, suggesting that it
is a plausible effect responsible for the nonlinearity of the solar activity
cycle.
%0 Generic
%1 citeulike:13807172
%A Isık, Emre
%D 2015
%K imported
%T A mechanism for the dependence of sunspot group tilt angles on cycle strength
%U http://arxiv.org/abs/1510.04323
%X The average tilt angle of sunspot groups emerging throughout the solar cycle
determines the net magnetic flux crossing the equator, which is correlated with
the strength of the subsequent cycle. I suggest that a deep-seated, non-local
process can account for the observed cycle-dependent changes in the average
tilt angle. Motivated by helioseismic observations indicating cycle-scale
variations in the sound speed near the base of the convection zone, I
determined the effect of a thermally perturbed overshoot region on the
stability of flux tubes and on the tilt angles of emerging flux loops. I found
that 5-20 K of cooling is sufficient for emerging flux loops to reproduce the
reported amplitude of cycle-averaged tilt angle variations, suggesting that it
is a plausible effect responsible for the nonlinearity of the solar activity
cycle.
@misc{citeulike:13807172,
abstract = {{The average tilt angle of sunspot groups emerging throughout the solar cycle
determines the net magnetic flux crossing the equator, which is correlated with
the strength of the subsequent cycle. I suggest that a deep-seated, non-local
process can account for the observed cycle-dependent changes in the average
tilt angle. Motivated by helioseismic observations indicating cycle-scale
variations in the sound speed near the base of the convection zone, I
determined the effect of a thermally perturbed overshoot region on the
stability of flux tubes and on the tilt angles of emerging flux loops. I found
that 5-20 K of cooling is sufficient for emerging flux loops to reproduce the
reported amplitude of cycle-averaged tilt angle variations, suggesting that it
is a plausible effect responsible for the nonlinearity of the solar activity
cycle.}},
added-at = {2019-03-25T08:20:55.000+0100},
archiveprefix = {arXiv},
author = {I\c{s}{\i}k, Emre},
biburl = {https://www.bibsonomy.org/bibtex/2fa2f1035bf464942201d849726184b30/ericblackman},
citeulike-article-id = {13807172},
citeulike-linkout-0 = {http://arxiv.org/abs/1510.04323},
citeulike-linkout-1 = {http://arxiv.org/pdf/1510.04323},
day = 14,
eprint = {1510.04323},
interhash = {9adc7bebd80c7acf89f187069ef9c86c},
intrahash = {fa2f1035bf464942201d849726184b30},
keywords = {imported},
month = oct,
posted-at = {2015-10-20 05:18:25},
priority = {2},
timestamp = {2019-03-25T08:20:55.000+0100},
title = {{A mechanism for the dependence of sunspot group tilt angles on cycle strength}},
url = {http://arxiv.org/abs/1510.04323},
year = 2015
}