title: Regional climate impacts of a possible future grand solar minimum.
abstract: Any reduction in global mean near-surface temperature due to a future decline in solar activity is likely to be a small fraction of projected anthropogenic warming. However, variability in ultraviolet solar irradiance is linked to modulation of the Arctic and North Atlantic Oscillations, suggesting the potential for larger regional surface climate effects. Here, we explore possible impacts through two experiments designed to bracket uncertainty in ultraviolet irradiance in a scenario in which future solar activity decreases to Maunder Minimum-like conditions by 2050. Both experiments show regional structure in the wintertime response, resembling the North Atlantic Oscillation, with enhanced relative cooling over northern Eurasia and the eastern United States. For a high-end decline in solar ultraviolet irradiance, the impact on winter northern European surface temperatures over the late twenty-first century could be a significant fraction of the difference in climate change between plausible AR5 scenarios of greenhouse gas concentrations.
authors.affiliation: Met Office Hadley Centre, Exeter EX1 3PB, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Ineson
authors.affiliation: 1] Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK [2] National Centre for Atmospheric Science, University of Oxford, Oxford OX1 3PU, UK.
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Maycock
authors.affiliation: 1] National Centre for Atmospheric Science, University of Oxford, Oxford OX1 3PU, UK [2] Department of Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford OX1 3PU, UK.
authors.forename: Lesley J
authors.initials: LJ
authors.lastname: Gray
authors.affiliation: Met Office Hadley Centre, Exeter EX1 3PB, UK.
authors.forename: Adam A
authors.initials: AA
authors.lastname: Scaife
authors.affiliation: Met Office Hadley Centre, Exeter EX1 3PB, UK.
authors.forename: Nick J
authors.initials: NJ
authors.lastname: Dunstone
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303 USA.
authors.forename: Jerald W
authors.initials: JW
authors.lastname: Harder
authors.affiliation: Met Office Hadley Centre, Exeter EX1 3PB, UK.
authors.forename: Jeff R
authors.initials: JR
authors.lastname: Knight
authors.affiliation: Department of Meteorology, University of Reading, Reading RG6 6BB, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Lockwood
authors.affiliation: Met Office Hadley Centre, Exeter EX1 3PB, UK.
authors.forename: James C
authors.initials: JC
authors.lastname: Manners
authors.affiliation: Met Office Hadley Centre, Exeter EX1 3PB, UK.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Wood