Robust climate responses to extreme solar minimum forcing and their
hemispheric differences
Abstract
Fundamental understanding of the climate responses to solar variability
is obscured by the large and complex climate variability. This
long-standing issue is addressed here by examining climate responses
under an extreme solar minimum (ESM) scenario, obtained by making the
sun void of all magnetic fields. It is used to drive a whole atmosphere
climate model with coupled ocean. The simulations reveal robust
responses in the coupled climate system, and elucidate similarities and
differences of responses to bottom-up and top-down forcing. Planetary
waves (PWs) play a key role in both regional climate and the mean
circulation changes. Responses of the largest scale PW during NH and SH
winters differ, leading to hemispheric differences in the interplay
between dynamical and radiative processes. The analysis exposes
remarkable general similarities between climate responses in ESM
simulations and those under nominal solar minimum conditions, even
though the latter may not appear to be statistically significant.