  The solar magnetism is no more considered as a purely superficial phenomenon.
The SoHO community has shown that the length of the solar cycle depends on the
transition region between radiation and convection. Nevertheless, the internal
solar (stellar) magnetism stays poorly known. Starting in 2008, the American
instrument HMI/SDO and the European microsatellite PICARD will enrich our view
of the Sun-Earth relationship. Thus obtaining a complete MHD solar picture is a
clear objective for the next decades and it requires complementary observations
of the dynamics of the radiative zone. For that ambitious goal, space
prototypes are being developed to improve gravity mode detection. The Sun is
unique to progress on the topology of deep internal magnetic fields and to
understand the complex mechanisms which provoke photospheric and coronal
magnetic changes and possible longer cycles important for human life. We
propose the following roadmap in Europe to contribute to this "impressive"
revolution in Astronomy and in our Sun-Earth relationship: SoHO (1995-2007),
PICARD (2008-2010), DynaMICS (2009-2017) in parallel to SDO (2008-2017) then a
world-class mission located at the L1 orbit or above the solar poles.
