Modeling the Transport and Deposition of 10Be Produced by the Strongest Solar Proton Event During the Holocene

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Spiegl, T. C., Yoden, S., Langematz, U., Sato, T., Chhin, R., Noda, S., Miyake, F., Kusano, K., Schaar, K., Kunze, M., Yoden, S.; 2 Graduate School of Science Kyoto University Kyoto Japan, Langematz, U.; 1 Institut für Meteorologie Freie Universität Berlin Berlin Germany, Sato, T.; 4 Japan Atomic Energy Agency Tokai Japan, Chhin, R.; 2 Graduate School of Science Kyoto University Kyoto Japan, Noda, S.; 2 Graduate School of Science Kyoto University Kyoto Japan, Miyake, F.; 6 Institute for Space‐Earth Environmental Research Nagoya University Nagoya Japan, Kusano, K.; 6 Institute for Space‐Earth Environmental Research Nagoya University Nagoya Japan, Schaar, K.; 1 Institut für Meteorologie Freie Universität Berlin Berlin Germany, Kunze, M.; 1 Institut für Meteorologie Freie Universität Berlin Berlin Germany
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: ddc:551.5; cosmogenic nuclides; atmospheric transport; surface deposition; modeling; Greenland; Antarc*; Antarctica; ice core
• Online Access: https://doi.org/10.1029/2021JD035658; http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10244

Prominent excursions in the number of cosmogenic nuclides (e.g., 10Be) around 774 CE/775 document the most severe solar proton event (SPE) throughout the Holocene. Its manifestation in ice cores is valuable for geochronology, but also for solar‐terrestrial physics and climate modeling. Using the ECHAM/MESSy Atmospheric Chemistry (EMAC) climate model in combination with the Warning System for Aviation Exposure to SEP (WASAVIES), we investigate the transport, mixing, and deposition of the cosmogenic nuclide 10Be produced by the 774 CE/775 SPE. By comparing the model results to the reconstructed 10Be time series from four ice core records, we study the atmospheric pathways of 10Be from its stratospheric source to its sink at Earth's surface. The reconstructed post‐SPE evolution of the 10Be surface fluxes at the ice core sites is well captured by the model. The downward transport of the 10Be atoms is controlled by the Brewer‐Dobson circulation in the stratosphere and cross‐tropopause transport via tropopause folds or large‐scale sinking. Clear hemispheric differences in the transport and deposition processes are identified. In both polar regions the 10Be surface fluxes peak in summertime, with a larger influence of wet deposition on the seasonal 10Be surface flux in Greenland than in Antarctica. Differences in the peak 10Be surface flux following the 774 CE/775 SPE at the drilling sites are explained by specific meteorological conditions depending on the geographic locations of the sites. Plain Language Summary: During large solar storms, high energy particles are hurled with enormous force toward Earth by the Sun. As these particles collide with atmospheric constituents (such as oxygen or nitrogen) unique nuclides of cosmogenic origin are formed in the higher atmosphere. From there they are transported downwards and finally precipitate at the surface due to different sink processes. Their imprints can be conserved over thousands of years within natural archives, such as ice cores or tree rings. Analysis of these ...