Solar forcing of the terrestrial atmosphere

TL;DR

This paper reviews how solar variability influences the Earth's atmosphere through various mechanisms, including radiative forcing and energetic particles, across different time scales, highlighting the complexity and uncertainties in understanding these effects.

Contribution

It provides a comprehensive review of multiple solar influence mechanisms on the terrestrial atmosphere, emphasizing less-understood processes beyond radiative forcing.

Findings

Radiative forcing is the most studied solar impact mechanism.

Other mechanisms like energetic particles can significantly influence the atmosphere.

The physics of weaker mechanisms remains poorly understood.

Abstract

The Sun provides the main energy input to the terrestrial atmosphere, and yet the impact of solar variability on long-term changes remains a controversial issue. Direct radiative forcing is the most studied mechanism. Other much weaker mechanisms, however, can have a significant leverage, but the underlying physics is often poorly known. We review the main mechanisms by which solar variability may impact the terrestrial atmosphere, on time scales ranging from days to millennia. This includes radiative forcing, but also the effect of interplanetary perturbations and energetic particle fluxes, all of which are eventually driven by the solar magnetic field.