Aubry Thomas J, Staunton-Sykes John, Marshall Lauren R, Haywood Jim, Abraham Nathan Luke, Schmidt Anja
Department of Geography, University of Cambridge, Cambridge, UK.
Sidney Sussex College, Cambridge, UK.
Nat Commun. 2021 Aug 12;12(1):4708. doi: 10.1038/s41467-021-24943-7.
Explosive volcanic eruptions affect climate, but how climate change affects the stratospheric volcanic sulfate aerosol lifecycle and radiative forcing remains unexplored. We combine an eruptive column model with an aerosol-climate model to show that the stratospheric aerosol optical depth perturbation from frequent moderate-magnitude tropical eruptions (e.g. Nabro 2011) will be reduced by 75% in a high-end warming scenario compared to today, a consequence of future tropopause height rise and unchanged eruptive column height. In contrast, global-mean radiative forcing, stratospheric warming and surface cooling from infrequent large-magnitude tropical eruptions (e.g. Mt. Pinatubo 1991) will be exacerbated by 30%, 52 and 15% in the future, respectively. These changes are driven by an aerosol size decrease, mainly caused by the acceleration of the Brewer-Dobson circulation, and an increase in eruptive column height. Quantifying changes in both eruptive column dynamics and aerosol lifecycle is therefore key to assessing the climate response to future eruptions.
火山爆发会影响气候，但气候变化如何影响平流层火山硫酸盐气溶胶的生命周期和辐射强迫仍未得到探索。我们将喷发柱模型和气溶胶 - 气候模型相结合，以表明在高端变暖情景下，与如今相比，频繁发生的中等强度热带火山喷发（如2011年的纳布罗火山喷发）所造成的平流层气溶胶光学厚度扰动将减少75%，这是未来对流层顶高度上升且喷发柱高度不变的结果。相比之下，未来不频繁发生的大规模热带火山喷发（如1991年的皮纳图博火山喷发）所导致的全球平均辐射强迫、平流层变暖及地表冷却将分别加剧30%、52%和15%。这些变化是由气溶胶粒径减小（主要由布勒尔 - 多布森环流加速导致）和喷发柱高度增加所驱动的。因此，量化喷发柱动力学和气溶胶生命周期的变化是评估未来火山喷发对气候响应的关键。
