Relationship
between Solar Magnetism and Irradiance
Aim of the team activities
The
relationship between elements of the photospheric magnetic field and
photospheric irradiance is the basis of most studies of solar
irradiance variability, but in spite of much published work and many
workshops on solar variations there is not yet a consensus on the
experimental phenomenology. On the theoretical side considerable
progress has been achieved, but there are still many open questions.
The major open question is the relative contributions of surface
magnetic variability and global changes to irradiance variations on
various time scales. Since understanding the drivers of solar
irradiance is a fundamental to interpreting the paleoclimate models
which indicate climate change on the Earth, establishing the proper
relation between solar magnetism and irradiance is one of the highest
priorities in solar research. The ISSI research team will produce
a coherent description of the influence of the photospheric magnetic
field on the solar irradiance, based on our best present
knowledge. The different data analysis methods historically
applied to irradiance imaging and magnetograms (image processing,
parameter calculations) will be compared and consensual empirical
models produced. Recent numerical simulations of theoretical models on
magnetic field structures and their effect on the newest irradiance
measurements will be applied to the problem. The experimental
work will concentrate on solar cycle 23 data.

Team
members
V.
Domingo, University of Valencia, Spain (team leader,
vdomingo@uv.es)
I.
Ermolli, INAF Osservatorio Astronomico di Roma, Italy
P.
Fox, High Altitude Observatory, Boulder, NCAR, Boulder, Colorado
C.
Fröhlich, Davos Physikalisch-Meteorologisches Observatorium / WRC,
Davos, Switzerland
G.
Kopp, Univ. of Colorado / Laboratory for Atmospheric and Space Physics,
Boulder, Colorado
M.
Haberreiter, Davos Physikalisch-Meteorologisches Observatorium / WRC,
Davos, Switzerland
J.
Pap, Goddard Space Flight Center, Greenbelt, Maryland
J.
Sánchez Almeida, Instituto de Astrofísica de Canarias, La
Laguna, Spain
P.
Scherrer, Stanford University, California
W.
Schmutz, Davos Physikalisch-Meteorologisches Observatorium / WRC,
Davos, Switzerland
M.
Schüssler, Max-Planck-Institut für Sonnensystemforschung,
Lindau, Germany
S.
Solanki, Max-Planck-Institut für Sonnensystemforschung, Lindau,
Germany
H.
Spruit, Max Plank Institut für Astrophysik, Garching, Germany
Y.
Unruh, Imperial College, London, United Kingdom
W.
Vögler, Max-Planck-Institut für Sonnensystemforschung,
Lindau, Germany
Full
Proposal text (open access)
Sessions:
First
meeting: 11-15 October 2004
First meeting attendees Presentations (restricted access)
V. Domingo
facular contrast CLV in
MDI images
I. Ermolli
PSTP, feature identification
methods, modelling
irradiacnce variations
P. Fox
PSTP_2004,
spectrum
synthesis
C. Fröhlich
G. Kopp
solar irradiance measurements
M. Haberreiter
modelling
spectral UV variability
J. Pap
J. Sánchez Almeida
P. Scherrer
MDI calibration issue
(by
teleconference)
W. Schmutz
H. Spruit
active regions enhanced
cooling
Y. Unruh
W. Vögler
Minutes
(restricted access)
Second meeting:
4-6 July 2005
Presentations (restricted access)
V. Domingo
la
palma observations
I. Ermolli
PSTP images, intensity and
magnetic measurements
P. Fox
radiative
models
C. Fröhlich
MOD
TSI composit revision
M. Haberreiter
COSI, model to calculate
solar intensity spectra
J. Pap
S. Solanki
simulations
of magnetoconvection
W. Schmutz
H. Spruit
Minutes (restricted
access)
Link to a draft of the webbook can be found here (restricted access)
Third meeting: 6-9 June 2006