Imaging: Imaging: intensity and magnetic measurementsintensity and magnetic measurements

Feature definition: Feature definition: by magnetograms, by by magnetograms, by filtergrams or else….filtergrams or else….

Empirical modelsEmpirical models

ISSI team – Session 2 – 4-6 July 2005

Still deepening…..Still deepening…..

Modelling irradiance variations Modelling irradiance variations through through

full-disk PSPT images andfull-disk PSPT images and

semi-empirical atmospheric modelssemi-empirical atmospheric models

ISSI team – Session 1 - 11-15 october 2004

Ilaria Ermolli 1

Francesco Berrilli 2, Mauro Centrone 1, Serena Criscuoli 2, Fabrizio Giorgi 1, Valentina Penza 1, Corrado Perna 1

1 INAF Osservatorio Astronomico di Roma 2 Università degli Studi di Roma “Tor Vergata”

Penza et al. 2004, A&A, 413, 1115

Ermolli et al. 2003, A&A, 412, 857

Test the capability of the models to reproduce the emergent intensity

Mod H

Mod F

Mod E

Test the capability of the models to reproduce the emergent intensity

Test the capability of the models to reproduce the emergent intensity

Mod E reproduces the network CLV

Computed/Measured 0.05% difference until =0.3

Mod F reproduces the facular CLV with a difference less than 1% until =0.3

Mod P and Mod H do not reproduce the measured facular CLV

Mod P and Mod H produce negative continuum facular contrast at the =1 , not measured

Slight model modifications to optimize details of this comparison

Test the capability of the models to reproduce the emergent intensity: main results

Small C variation in time (2000> 2003-04)

Dependence on the feature id: Mag > CaII K > B-R > Chapman meth

Count magnetic “ingredients” of solar variability

Count magnetic “ingredients” of solar variability

5 components -> 86% of TSI variance

4 components -> 98% of TSI variance

Rome PSPT images 2555 daysVIRGO (total)

RISE- SATIRE models

June- July 2004

Magnetic “ingredients” of solar variability

Spot (umbra, penumbra), faculae, network -> 86% of TSI variance

Their respective weight

Study limitations of decomposing the Sun into structures

Reconstruction of the disk integrated spectrum (VIRGO TSI): Main results

Whether variation of the coverage factors alone

and/or emergent intensity

The use of a set of 1D models simplifies the approach, but needs a correct determination of the coverage factors, that are strongly dependent on the feature identification procedures.

Spot (umbra, penumbra), faculae, quiet sun -> 98% of TSI variance

Feature id more important than spatial scale and seeing effects