Seppälä Annika, Kalakoski Niilo, Verronen Pekka T, Marsh Daniel R, Karpechko Alexey Yu, Szelag Monika E
Department of Physics, University of Otago, Dunedin, New Zealand.
Space and Earth Observation Centre, Finnish Meteorological Institute, Helsinki, Finland.
Nat Commun. 2025 Jan 16;16(1):748. doi: 10.1038/s41467-025-55966-z.
Solar driven energetic particle precipitation (EPP) is an important factor in polar atmospheric ozone balance and has been linked to ground-level regional climate variability. However, the linking mechanism has remained ambiguous. The observed and simulated ground-level changes start well before the processes from the main candidate, the so-called EPP-indirect effect, would start. Here we show that initial reduction of polar mesospheric ozone and the resulting change in atmospheric heating rapidly couples to dynamics, transferring the signal downwards, shifting the tropospheric jet polewards. This pathway is not constrained to the polar vortex. Rather, a subtropical route initiated by a changing wind shear plays a key role. Our results show that the signal propagates downwards in timescales consistent with observed tropospheric level climatic changes linked to EPP. This pathway, from mesospheric ozone to regional climate, is independent of the EPP-indirect effect, and solves the long-standing mechanism problem for EPP effects on climate.
太阳驱动的高能粒子沉降（EPP）是极地大气臭氧平衡的一个重要因素，并且已被证明与地面区域气候变化有关。然而，其关联机制仍不明确。观测到的和模拟的地面变化在主要候选机制（即所谓的EPP间接效应）所引发的过程开始之前就已经显著出现。在此，我们表明，极地中层大气臭氧的初始减少以及由此导致的大气加热变化会迅速与动力学耦合，将信号向下传递，使对流层急流向极地移动。这条路径并不局限于极涡。相反，由风切变变化引发的亚热带路径起到了关键作用。我们的结果表明，该信号在与观测到的与EPP相关的对流层气候变化相一致的时间尺度上向下传播。这条从中层大气臭氧到区域气候的路径独立于EPP间接效应，解决了长期存在的EPP对气候影响的机制问题。
