Description

Perturbation theory helps us linearize the radiative transfer equation for polarized light in order to understand the sensitivity of Stokes profiles to perturbations of the various physical quantities that characterize the solar atmosphere. The diagnostics that can be extracted from the polarized spectra directly come from the so-called response functions. Such functions are at the heart of our inversion codes of the radiative transfer equation.

We carry out magnetohydrodynamic studies of the flux tube storage. They are aimed at understanding the origin of sunspots, which are supposed to ascend up to the photosphere from the bottom of the convective zone, where a limit layer is located (the tachocline) between the convective zone —with differential rotation— and the radiative zone —with a rigid rotation. Toroidal flux tubes from this limit layer are thought to raise all the way through the convection zone to form sunspots. 

The concentration of cosmogenic isotopes (Berilium 10 and Carbon 14) in ice samples from the Arctic (Greenland) and the Antarctica are analyzed. The goal is to reconstruct the the history of solar magnetism. We have succeeded in reconstructing the last 10000 years so far. 

Qualitative studies of the Earth's magnetic fiel polarity inversions are obtained through relatively simple models of Statistical Mechanics, which are a generalization of the Ising/Heisenberg model.