Solar forcing influences the Earth’s atmosphere through variations in solar irradiance and energetic particle precipitation, with the latter heavily modulated by the strength and configuration of the Earth’s magnetic field. Together, these processes affect atmospheric composition, Earth’s radiative balance, and atmospheric dynamics across different timescales. Numerical modelling is an essential tool for investigating these interactions and understanding how solar forcing and the geomagnetic field affect the atmosphere and climate.
This multidisciplinary session welcomes contributions using chemistry-climate models, Earth system models, and related modelling frameworks to investigate interactions among solar forcing, atmospheric composition, atmospheric dynamics, and climate under present-day, past, and future boundary conditions. Key topics include, but are not limited to, the production of odd nitrogen (NOx) and odd hydrogen (HOx), ozone changes, radiative and dynamical responses, atmosphere-ocean coupling, and Earth system feedback.
We encourage studies exploring the role of changes in the geomagnetic field, including variations in field strength as well as geomagnetic excursions and reversals, in modulating energetic particle precipitation and its atmospheric effects. Contributions spanning individual solar proton events and geomagnetic storms, solar cycle variability, grand solar minima, and geomagnetic excursions are particularly welcome. Studies addressing model development, parameterisations of solar and particle forcing, validation against observations and cosmogenic radionuclide records, model intercomparisons, and uncertainty assessment are also encouraged.
By bringing together experts in atmospheric chemistry, climate dynamics, solar-terrestrial physics, geomagnetism, and Earth system modelling, this session aims to support interdisciplinary discussion and improve our understanding of how solar and geomagnetic forcings influence Earth’s atmosphere and climate, from individual events to long-term Earth history.
This session is dedicated to the memory of Dr Eugene Rozanov (1955-2026), whose pioneering contributions to chemistry-climate modelling and solar-terrestrial interactions continue to inspire research across these disciplines.