Are Changes in the Solar Meridional Circulation Responsible for the Current Minimum?
Andrés Muñoz-Jaramillo [munoz@mithra.physics.montana.edu], Montana State University,
Bozeman; Dibyendu Nandy, Indian Institute for Science Education and Research, Kolkata,
West Bengal; and Petrus C.H. Martens, Montana State University, Bozeman and HarvardSmithsonian Center for Astrophysics, Cambridge, Massachusetts
The current minimum in the solar cycle has been the deepest we have experienced in the
space age. An event such as this challenges our understanding of the solar cycle and
provides an opportunity to probe the physical processes underlying the dynamo mechanism
that ultimately governs the variability of solar magnetic fields. Under the current paradigm, a
meridional circulation involving axisymmetric plasma motions between the solar poles and
equator plays a major role in setting the period of the solar cycle. Observations provide
strong evidence that this circulation changes with time; this makes it a natural suspect as a
cause of this unusually long minimum. But are meridional circulation changes enough to
explain it? In this study we attempt to address this question using our state of the art
kinematic dynamo model which incorporates a novel treatment for active region formation
and their contribution to the solar poloidal field.