Invited speakers: Maria Dasi Espuig, Gerard Thuillier, and Kok Leng Yeo

We solicit contributions involving spectral and total solar irradiance observations, as well as irradiance proxies such as sunspots, the Mg II index, radio flux, magnetic field measurements, etc.. Solar irradiance model progress and comparisons are also invited, as well as studies on the mechanisms underlying solar irradiance variability (e.g., solar surface brightness distribution and evolution of solar features such as plages). Proxies are essential for filling gaps in irradiance measurements, inter-instrument comparisons, and as inputs to irradiance models. Recent updates to solar irradiance composites resulting from better instrument calibrations, refinements to inter-instrument comparisons, or new assessments of the long-term stabilities of irradiance records or proxies are invited. Studies of solar variability on both rotational, solar cycle timescales and beyond are welcome.

Please note that abstracts submitted to session ST5.3 "Space Weather in Planetary Systems" have been transferred to this session.