Variations of the solar diameter and shape are ultimately linked to changes in the interior of the Sun, associated with evolutionary processes, solar activity and solar energy output. Their investigation is important for the Earth’s climate research and fundamental physics.

Significant progress has been made from precise measurements from the ESA-NASA SOHO space mission. These measurements provide us a unique opportunity to study in detail changes of the global solar properties and their relationship to changes in the Sun’s interior, obtained from helioseismology. The team composed of specialists in the field of solar diameter and shape measurements, helioseismology and solar modeling, intends to investigate these changes and relationships using data from SOHO and ground-based observatories, compare with theoretical models of solar variability and discuss new approaches to data analysis and interpretation from the new space missions, notably Golf-NG\Dynamics and Solar Dynamics Observatory.