1. PICARD 2010 SciAdv/Charbonneau
PICARD-related research at the Université de Montréal
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

2. 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

3. 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

4. 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 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