Galactic cosmic rays constantly bombard the Earth’s atmosphere and induce cascades of nuclear reactions that produce various particles. One of the products of such interactions is cosmogenic nuclides, very useful tools for researches in different areas, such as solar physics, atmospheric physics, geomagnetic studies, hydrology, archeology, and many others. Their production rates are not uniform over the globe. Due to the changing shielding effect of the Earth’s geomagnetic field from cosmic rays, the production is higher in polar regions than near the equator. Furthermore, the production of cosmogenic nuclides varies greatly with altitude. In addition, the cosmic ray flux changes over time, following variations in solar activity. Several production models are available that account for all these effects (Poluianov et al., 2016, 2020), but their use requires some learning of computational details. To simplify the application of these models, we present calculated time series of the production rates for ³H, ⁷Be, ¹⁰Be, ¹⁴C, ²²Na, and ³⁶Cl, covering more than a century up to the present day. The results provide altitude-longitude-latitude resolution for each nuclide, include recent cosmic-ray data for the beginning of the 20th century, and account for the slow evolution of the geomagnetic field.

How to cite: Poluianov, S., Kovaltsov, G., Usoskin, I., and Kurita, N.: Production rates of atmospheric cosmogenic nuclides 3H, 7Be, 10Be, 14C, 22Na, 36Cl calculated for the 20th and early 21st centuries, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12244, https://doi.org/10.5194/egusphere-egu25-12244, 2025.

Measurements of the cosmogenic isotope concentrations in the natural archives are valuable sources of information about the variability of solar activity and parameters of explosive events in the solar system and our galaxy. The retrieval and understanding of the forcing peculiarities from the data requires detailed modeling of all relevant processes. Therefore, any applied model should be able to treat the production, transport, chemical transformation, and deposition of cosmogenic isotopes and atmospheric state parameters regulating their life cycle. A hierarchy of such models ranging from simple box models to full-scale Erath system models has been developed and utilized since 1990th. This lecture will briefly present the critical turning points in model development. Then I will discuss contemporary approaches to simulate the transport, chemistry, mixing, and deposition of different cosmogenic isotopes produced by galactic cosmic rays and solar proton events and the most promising ways of further development. Special attention will be paid to the influence of volcanic eruptions and integrating ¹⁰Be modeling with other species such as ³⁶Cl and ¹⁴C.

Acknowledgement: Support from Oulu University (Project GERACLIS #24304650) and collaborative Swiss French project AEON (grant no. 200020E_219166).

How to cite: Rozanov, E., Egorova, T., Golubenko, K., Baroni, M., Sukhodolov, T., and Usoskin, I.: An overview of available models for simulations of the life cycle of cosmogenic isotopes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2464, https://doi.org/10.5194/egusphere-egu25-2464, 2025.

Cosmogenic ¹⁰Be isotope is an important proxy for past solar activity that can be measured from natural archives such as ice cores. It is mostly produced in the stratosphere and its atmospheric lifetime until the deposition to the surface depends on different transport processes. In the troposphere, ¹⁰Be deposition to natural archives occurs comparatively quickly, being dominated by scavenging, with weather patterns causing regional variations. The stratospheric and cross-tropopause transport of the isotopes is affected by their attachment to the stratospheric aerosol particles, presenting an additional effect of size-dependent gravitational sedimentation.  Strong volcanic eruptions massively increase the stratospheric aerosol loading, thus increasing its effect on the ¹⁰Be transport and deposition, which has been proposed as a major complication term in the interpretation of proxy records. In our study, we address this effect by employing the state-of-the-art aerosol-chemistry-climate model SOCOL-AERv2-Be that has a full ¹⁰Be atmospheric cycle, including its attachment to aerosol particles. We isolate the effects of sedimentation by comparing simulations with and without it for the ¹⁰Be tracer. In these simulations we examine the long-term climatological effects of a background aerosol layer on the ¹⁰Be distribution in the atmosphere and the resulting deposition maps. In another set of simulations we specifically focus on the influence of the enhanced stratospheric aerosol layer after volcanic events of various magnitudes, including their large-scale dynamical effects on the ¹⁰Be transport induced by the lower stratospheric heating. The results are compared with ice core data from the Greenland and Antarctic stations.

How to cite: Jörimann, A., Sukhodolov, T., Harra, L., Baroni, M., Rozanov, E., and Egorova, T.: Volcanic modulation of Beryllium-10 atmospheric transport, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20054, https://doi.org/10.5194/egusphere-egu25-20054, 2025.

Beryllium isotopes, i.e. cosmogenic meteoric ¹⁰Be and stable ⁹Be, enter the oceans through distinct pathways. Beryllium-10 is produced in the atmosphere and enters the oceans mainly via precipitation, while ⁹Be is sourced from continents. Beryllium isotopes with a short oceanic residence time (10²-10³ yrs) display non-conservative behaviour in seawater. The ¹⁰Be/⁹Be proxy has been utilized as a powerful tool for quantifying diverse processes, including geomagnetism, sedimentation, continental input, and ocean circulation. Substantial effort has been invested in understanding external sources and internal cycling of Be isotopes in the recent decade, such as constraints on the global distribution of ¹⁰Be depositional fluxes and on riverine and benthic ⁹Be inputs. Hence, it offers an excellent opportunity to revisit their modern oceanic cycle. Here, we investigate the controls on the modern oceanic cycling of Be isotopes using a three-dimensional ocean biogeochemical model constrained by water-column distributions of ⁹Be and ¹⁰Be compiled from the literature. In addition to modelling the previously identified controls, we highlight the critical role of marine benthic fluxes and scavenging on particulate organic matter and opal in governing the mass balance and spatial distribution of Be isotopes. The transport of Be isotopes between basins by circulation is of lesser importance compared to external inputs at continent/atmosphere–ocean boundaries, except in the South Pacific. Consequently, the basin-wide ¹⁰Be/⁹Be ratio predominantly reflects the pattern of external inputs across most basins in the modern ocean. Based on our data-constrained oceanic model, we can further assess the sensitivity of basin-wide ¹⁰Be/⁹Be ratios to changes in external sources, such as continental denudation, and internal cycling, such as particle scavenging. The mechanistic understanding developed from this Be cycling model provides important insights into the various applications of marine Be isotopes, and offers additional tools to assess the individual effects of geomagnetism and environment on cosmogenic ¹⁰Be/⁹Be records in marine sediments.

How to cite: Deng, K., de Souza, G., and Du, J.: Modelling the modern oceanic cycle of beryllium-10 and beryllium-9, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2277, https://doi.org/10.5194/egusphere-egu25-2277, 2025.

Perched precariously upon the deepest continental location on Earth, East Antarctica’s Denman Glacier is hypersensitive to changes in both air and ocean temperatures. Shackleton Ice Shelf buttresses Denman Glacier, regulating the rate at which it flows into the Southern Ocean. However, under warming ocean conditions along the continental shelf – a function of increased upwelling of warm Circumpolar Deep Water (CDW) in many places around Antarctica – Shackleton Ice Shelf may become unstable and collapse. Loss of the ice shelf would destabilise the glacier in turn, and a complete collapse of the Denman System could contribute +1.5 m to global sea level. Besides what began 15 years ago, observational ocean data show that the interactions between upwelling CDW and regional calving margins is otherwise unprecedented in historical records, and of unknown influence on longer timescales. Here we aim to resolve two questions: is warm CDW currently reaching the glacier’s grounding line? And is there any evidence of CDW presence within the Shackleton Ice Shelf on a Holocene timescale? Utilising a Conductivity-Temperature-Depth (CTD) profile and a 1m sediment core collected from the seafloor beneath Shackleton Ice Shelf during the 2023-24 Denman Terrestrial Campaign, we employ meteoric-¹⁰Be signatures from sediment samples – which have been shown to reflect upwelling circumpolar deep-water conditions along the Antarctic continental shelf – to discuss the modern and paleo-ocean conditions within the Shackleton Ice Shelf cavity.

How to cite: Jeromson, M., Husdell, M., Bostock, H., Fink, D., Simon, K., Rieke, O., Thompson, S., Rosevear, M., Nothdurft, L., Herraiz–Borreguero, L., and White, D.: An assessment of modern and past Circumpolar Deep Water presence beneath Shackleton Ice Shelf, East Antarctica: insights into using Meteoric Beryllium-10, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15088, https://doi.org/10.5194/egusphere-egu25-15088, 2025.

Cosmogenic nuclides are invaluable tools for quantifying denudation and uplift rates and thus decoding geological processes that act over different timescales and leave distinct imprints on the Earth’s surface. Among these, meteoric ¹⁰Be has emerged as a particularly powerful proxy due to its unique capability of being measured independently of lithology. Meteoric ¹⁰Be is an atmospheric flux tracer, and when normalized to stable ⁹Be, a trace element released by rocks during weathering, the ¹⁰Be/⁹Be ratio emerges. This ratio can be measured on small sample amounts and is independent of the presence of quartz which provides a benefit over the “sister” nuclide in situ ¹⁰Be that has been widely used in landscapes of felsic rocks.

The Albanides orogenic belt is a tectonically active region characterised by a remarkable lithological diversity, including carbonates, ophiolites, siliciclastics, metamorphics, and volcanic rocks distributed over short distances. In the Albanides´quartz-bearing sector, in situ ¹⁰Be-derived denudation rates were recently measured, but large areas of this belt remained unexplored due to lack of quartz. Meteoric ¹⁰Be/⁹Be -derived denudation rates fill this gap. When combined with geomorphic analyses to investigate uplift patterns in equilibrated river systems, results from both cosmogenic nuclides systems are consistent, and reveal significant spatial variability in denudation and uplift rates ranging from 0.1 to over 1.5 mm/yr. These results suggest that the Albanides are undergoing rapid landscape evolution, with rates and uplift mechanisms varying considerably across the belt. Our findings underscore the versatility of the meteoric ¹⁰Be/⁹Be method as a robust approach providing key information for quantifying erosional processes, sediment transport dynamics, landscape development and tectonic evolution. The consistency between the two datasets strengthens the reliability of the meteoric ¹⁰Be/⁹Be technique across regions with diverse geological compositions. Overall, our approach paves the way for future studies aimed at exploring the interplay between tectonics, climate, and surface processes using cosmogenic nuclides in complex lithological settings.

How to cite: Bazzucchi, C., Wittmann, H., Crosetto, S., Ballato, P., Faccenna, C., and Rossetti, F.: Meteoric 10Be/9Be as a Proxy for Denudation and Uplift in the active Albanides orogenic belt, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13118, https://doi.org/10.5194/egusphere-egu25-13118, 2025.

We investigated chemical weathering in the subglacial environment of East Antarctica through studies of two isotope systems: meteoric ¹⁰Be and (²³⁴U/²³⁸U). We sampled blue ice moraines as a window into Antarctica’s subglacial environments. Here vapour-starved winds ablate near-stagnant ice, allowing sediment-rich basal ice to be thrust against mountains and nunataks. These moraines form across a wide swath of the continent. Many blue ice moraine sediments are substantially altered by chemical weathering; sediment grains are often coated in a mix of clays, oxides, and amorphous material that does not resemble soil but speaks to a chemical weathering regime specially found in the subglacial environment.

Meteoric ¹⁰Be works as a tracer in this system because its concentration in ice is relatively well known from ice cores, it is very unlikely to occur in detrital minerals, and it has a strong propensity to become incorporated in authigenic minerals, such as clays and oxyhydroxides. The total abundance of meteoric ¹⁰Be therefore traces meltwater input over the sediment residence time and the speciation of meteoric ¹⁰Be traces the formation of authigenic minerals.

In developing the meteoric ¹⁰Be tracer, we initially focused on Mt. Achernar Moraine, a site in the central Transantarctic Mountains containing highly weathered fine sediments of subglacial origin. We tested a variety of extraction procedures to most effectively extract ¹⁰Be from minerals formed during chemical weathering. At Mt. Achernar Moraine, the total meteoric ¹⁰Be strongly correlates to the abundance of authigenic minerals (particularly smectite clay) and aligns well with mass balance calculations for meltwater input.

The use of (²³⁴U/²³⁸U) as a tracer relies on the loss of ²³⁴U due to alpha recoil. As a result, (²³⁴U/²³⁸U) in residual detrital silt and clay particles drops below equilibrium and progresses towards a low steady state value. By contrast, the surrounding solutions and authigenic minerals that precipitate from them display (²³⁴U/²³⁸U) ratios higher than equilibrium.

Analyses of several samples from Mt. Achernar Moraine, show that U series isotopes confirm recent (i.e. within 100 ka) authigenic weathering at the site. Clay mineral (²³⁴U/²³⁸U) ratios are higher than those of silt, suggesting a mix of detrital and authigenic clay. Adsorbed species, carbonates, and oxyhydroxides display (²³⁴U/²³⁸U) higher than equilibrium, reflecting their precipitation from ²³⁴U-enriched solutions.

The results in total are very promising for both isotope systems. The U series system can constrain the time frame of chemical alteration to within a glacial-interglacial cycle.  The ¹⁰Be system trace the meltwater input and also confirm the presence of authigenic mineral phases. These tracers, especially in combination, allow us to define the relationship between meltwater input and weathering intensity across Antarctica and make large scale influences about the ice sheet’s influence on its substrate and on global biogeochemical cycles.

How to cite: Graly, J., Torfstein, A., Arnardóttir, E., Licht, K., and Caffee, M.: Combining meteoric 10Be and U-series isotopes to decode weathering intensity in East Antarctica’s subglacial environment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17083, https://doi.org/10.5194/egusphere-egu25-17083, 2025.