A new technique for comparing solar dynamo models and observations

¹ Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina e-mail: mininni@df.uba.ar
² Instituto de Astronomía y Física del Espacio, CONICET, Ciudad Universitaria, 1428 Buenos Aires, Argentina e-mail: dgomez@df.uba.ar

Received: 11 March 2004
Accepted: 5 July 2004

Abstract

We present a new technique suitable for a detailed comparison between solar dynamo models and observations. The method is based on the technique of dynamo spectroscopy proposed by Hoyng & Schutgens ([CITE]) and bi-orthogonal decomposition of solar data. This decomposition provides a representation of the mean and fluctuating components of the flows, yielding relevant information for the comparison. To illustrate the method, we use a simple kinematic dynamo model of the solar cycle. Irregularities are introduced in the evolution of the magnetic fields modeling the turbulent behavior of the solar convective region with a random perturbation on the external source for the poloidal field. After fine tuning the parameters of the model we obtain solar like solutions displaying a magnetic cycle of 22 years, with fluctuations in its period and amplitude. In addition, the model generates Maunder-like events with a time span of 60-100 years.