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PICARD-related research at the Université de Montréal http://www.astro.umontreal.ca/~paulchar/grps. MHD simulations of solar convection (Ghizaru, Cossette, Beaudoin, Bouchat, Racine) Solar cycle modelling (St-Laurent-Lemerle, Simard)
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PICARD-related researchat the Université de Montréalhttp://www.astro.umontreal.ca/~paulchar/grps • MHD simulations of solar convection (Ghizaru, • Cossette, Beaudoin, Bouchat, Racine) • Solar cycle modelling (St-Laurent-Lemerle, Simard) • Total and spectral irradiance modelling (Thibault, Bolduc) 2010 Highlights: • Solar-like cycles in global 3D MHD simulations • TSI reconstruction model extended to near- and mid-UV • spectral irradiance • Secured 3-yr support from CSA’s SSEP program. PICARD 2010 SciAdv/Charbonneau
MHD simulations of solar convection MHD version of EULAG; full-spherical shell anelastic simulation with rotation and stratification, including convection zone and underlying stable layer. Low dissipation regime, long temporal spans. Well-defined axisymmetric component, antisymmetric about equatorial plane; Hemispherically synchronous polarity reversals on ~30 yr timescale. Toroidal magnetic field beneath core-envelope interface PICARD 2010 SciAdv/Charbonneau
Impact on convective energy transport Zonal mean of toroidal magnetic field at the core-envelope interface (r/R=0.718)) We detect a weak but clear cyclic signal in the convective transport of energy throughout the convective envelope. Zonal mean of temperature perturbation at the core-envelope interface Temperature modulation already present at the base of the convective envelope, varying in phase with the cycle. Zonal mean of temperature perturbation below the surface (r/R=0.96). Weak but significant temperature excess at the top of the simulation domain, at « maximum » phase of cycle. PICARD 2010 SciAdv/Charbonneau
Total and spectral solar irradiance modelling Fragmentation+erosion model for emerging active regions, coupled to a 3-component model: quiet sun + sunspots + « faculae »; calibrated on 1978-2007 PMOD (TSI) or UARS (UVSI) and sunspot area time series. In works: addition of a magnetic network component, generalization to synthesis of spectral irradiance time series in near- and mi-UV: UVSI: Bolduc, Charbonneau, Bourqui & Crouch, in prep. TSI: Crouch et al. 2008, ApJ, 677, 723 PICARD 2010 SciAdv/Charbonneau