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Reconstructing Cenozoic history of continental silicate weathering is crucial for understanding Earth’s carbon cycle and greenhouse history. The question of whether continental silicate weathering increased during the late Cenozoic, setting the stage for glacial cycles, has remained controversial for decades. Whereas numerous independent proxies of weathering in ocean sediments (e.g., Li, Sr, and Os isotopes) have been interpreted to indicate that the continental silicate weathering rate increased in the late Cenozoic, beryllium isotopes in seawater have stood out as an important exception. Beryllium isotopes have been interpreted to indicate stable continental weathering and/or denudation rates over the last 12 Myr. Here we present a Be cycle model whose results show that variations in the ⁹Be weathering flux are counterbalanced by near-coastal scavenging while the cosmogenic 10Be flux from the upper atmosphere stays constant. As a result, predicted seawater 10Be/⁹Be ratios remain nearly constant even when global denudation and Be weathering rates increase by three orders of magnitude. Moreover, 10Be/⁹Be records allow for up to an 11-fold increase in Be weathering and denudation rates over the late Cenozoic, consistent with estimates from other proxies. The large increase in continental weathering indicated by multiple proxies further suggests that the increased CO₂ consumption by continental weathering, driven by mountain-building events, was counter-balanced by other geological processes to prevent a runaway icehouse condition during the late Cenozoic. These processes could include enhanced carbonate dissolution via pyrite weathering, accelerated oxidation of fossil organic carbon, and/or reduced basalt weathering as the climate cooled.

Denudation is one of the main processes that shapes landscapes. Because temperature, precipitation and glacial extents are key factors involved in denudation, climatic fluctuations are thought to exert a strong control on this parameter over geological timescales. However, the direct impacts of climatic variations on denudation remain controversial, particularly those involving the Quaternary glacial cycles in mountain environments. Here we measure in situ cosmogenic 10 Be concentration in quartz in marine turbidites of two high-resolution cores collected in the Mediterranean Sea, providing a near-continuous (temporal resolution of ~1–2 kyr) reconstruction of denudation in the Southern Alps since 75 kyr ago (ka). This high-resolution palaeo-denudation record can be compared with well-constrained climatic variations over the last glacial cycle. Our results indicate that total denudation rates were approximately two times higher than present during the Last Glacial Maximum (26.5–19 ka), the glacial component of the denudation rates being 1 . 5 − 1.0 + 0.9  mm yr −1 . However, during moderately glaciated times (74–29 ka), denudation rates were similar to those today (0.24 ± 0.04 mm yr − 1 ). This suggests a nonlinear forcing of climate on denudation, mainly controlled by the interplay between glacier velocity and basin topography. Hence, the onset of Quaternary glaciations, 2.6 million years ago, did not necessarily induce a synchronous global denudation pulse. Constraints on the denudation of the Southern Alps over the last glacial cycle indicate a nonlinear influence of climate on landscape evolution in glaciated areas, according to a beryllium isotope record measured from quartz in a sequence of Mediterranean turbidites.

Northern Hemisphere insolation intensity is roughly in phase with Southern Hemisphere climate proxies, leading to a common conclusion that northern insolation forces southern climate during the Late Quaternary. However, mid-latitude Southern Hemisphere records place the advance of Patagonian and New Zealand glaciers before the Last Glacial Maximum (29,000–18,000 years ago) by several millennia. To resolve the cause(s) of nearly synchronous global climate change requires continuous archives of mid-latitude glacial activity for the last glacial cycle. Here we assess the position of the Patagonian Ice Sheet’s marine-terminating margin over the last ~89,000 years using a sedimentary-beryllium-isotope record from the Chilean margin to track the proximity of local glaciers. We find that glaciations and deglaciations are synchronous with or precede Northern Hemisphere ice sheets by thousands of years. Glacial expansion was driven by equatorward migration and strengthening of the southern westerly winds, linked to global cooling and a steeper meridional temperature gradient. Glacial terminations occurred when global warming coincided with increasing obliquity and dramatic Northern Hemisphere cooling. Our results suggest that, on orbital timescales, a complex interaction between mean global climate, obliquity and interhemispheric teleconnections could have led to near-synchronous global ice sheet evolution through displacements of the southern westerlies. Patagonian ice sheet changes largely mirrored those of the Northern Hemisphere over the last glacial cycle owing to displacements of the southern westerly winds, according to beryllium isotope constraints.

The international ice core community has a target to obtain continuous ice cores stretching back as far as 1.5 Myr. This would provide vital data (including a CO2 profile) allowing us to assess ideas about the cause of the Mid-Pleistocene Transition (MPT). The European Beyond EPICA project and the Australian Million Year Ice Core project each plan to drill such a core in the region known as Little Dome C. Dating the cores will be challenging, and one approach will be to match some of the records obtained with existing marine sediment datasets, informed by similarities in the existing 800 kyr period. Water isotopes in Antarctica have been shown to closely mirror deepwater temperature, estimated from Mg/Ca ratios of benthic foraminifera, in a marine core on the Chatham Rise near to New Zealand. The dust record in ice cores resembles very closely a South Atlantic marine record of iron accumulation rate. By assuming these relationships continue beyond 800 ka, our ice core record could be synchronised to dated marine sediments. This could be supplemented, and allow synchronisation at higher resolution, by the identification of rapid millennial-scale events that are observed both in Antarctic methane records and in emerging records of planktic oxygen isotopes and alkenone sea surface temperature (SST) from the Portuguese Margin. Although published data remain quite sparse, it should also be possible to match 10Be from ice cores to records of geomagnetic palaeo-intensity and authigenic 10Be/9Be in marine sediments. However, there are a number of issues that have to be resolved before the ice core 10Be record can be used. The approach of matching records to a template will be most successful if the new core is in stratigraphic order but should also provide constraints on disordered records if used in combination with absolute radiogenic ages.

The cosmogenic radionuclides 7Be and 10Be are useful tracers for atmospheric transport studies. Combining 7Be and 10Be measurements with an atmospheric transport model can not only improve our understanding of the radionuclide transport and deposition processes but also provide an evaluation of the transport process in the model. To simulate these aerosol tracers, it is critical to evaluate the influence of radionuclide production uncertainties on simulations. Here we use the GEOS-Chem chemical transport model driven by the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis to simulate 7Be and 10Be with the state-of-the-art production rate from the CRAC:Be (Cosmic Ray Atmospheric Cascade: Beryllium) model considering realistic spatial geomagnetic cutoff rigidities (denoted as P16spa). We also perform two sensitivity simulations: one with the default production rate in GEOS-Chem based on an empirical approach (denoted as LP67) and the other with the production rate from the CRAC:Be but considering only geomagnetic cutoff rigidities for a geocentric axial dipole (denoted as P16). The model results are comprehensively evaluated with a large number of measurements including surface air concentrations and deposition fluxes. The simulation with the P16spa production can reproduce the absolute values and temporal variability of 7Be and 10Be surface concentrations and deposition fluxes on annual and sub-annual scales, as well as the vertical profiles of air concentrations. The simulation with the LP67 production tends to overestimate the absolute values of 7Be and 10Be concentrations. The P16 simulation suggests less than 10 % differences compared to P16spa but a significant positive bias (∼18 %) in the 7Be deposition fluxes over East Asia. We find that the deposition fluxes are more sensitive to the production in the troposphere and downward transport from the stratosphere. Independent of the production models, surface air concentrations and deposition fluxes from all simulations show similar seasonal variations, suggesting a dominant meteorological influence. The model can also reasonably simulate the stratosphere–troposphere exchange process of 7Be and 10Be by producing stratospheric contribution and 10Be/7Be ratio values that agree with measurements. Finally, we illustrate the importance of including the time-varying solar modulations in the production calculation, which significantly improve the agreement between model results and measurements, especially at mid-latitudes and high latitudes. Reduced uncertainties in the production rates, as demonstrated in this study, improve the utility of 7Be and 10Be as aerosol tracers for evaluating and testing transport and scavenging processes in global models. For future GEOS-Chem simulations of 7Be and 10Be, we recommend using the P16spa (versus default LP67) production rate.

AimsWith the wide application of 7Be (Beryllium-7) in soil erosion investigations, retention and interception of 7Be by vegetation plays an important role in documenting soil 7Be redistribution, with a large impact on the interpretation of 7Be measurements. However, the dynamic and temporal changes in plants and the relationship with soil 7Be concentration remain unclear, and the significance of dead plants in 7Be interception is under-researched.MethodsThe samples of single plants (6 different species), compositive plants (including living and dead plants), along with soil reference on the Loess Plateau were collected individually to analyze the variations of 7Be concentration during the growth period from 2010 to 2012.ResultsThe accumulation of 7Be per mass is significantly higher in leaves than stems. The 7Be activity per mass and per area in living plants with seasonal trends ranged from 173.9 to 703.1 Bq kg–1 and 21.5 to 190.1 Bq m–2, respectively, and in dead plants ranged from 381.8 to 964.5 Bq kg–1 and 30.4 to 285.7 Bq m–2. Precipitation accounted for the largest contribution to the accumulation of 7Be in plants, followed by plant growth, species and parts. Plants accounted for 7Be interception on slope up to 66% (living plants accounted for 7% ~ 31% and dead plants accounted for 6% ~ 44%). The interception of living plants is low at first, then increases with the accumulation of rainfall and biomass together.ConclusionsOur results highlight that 7Be in plants (especially for the dead plants) is of great significance for 7Be in soil on the slope, and is controlled by precipitation, growth status and plant characteristics. The reference information obtained in this work will contribute to improving the accuracy of 7Be tracing technology, and broadening its scope.

The unique opportunity presented by 10B + 10B reactions to study high-energy, high-spin states in the A=10 mass region is explored. Results from the measurement at 72 MeV are presented, the most important being new and rarely seen states in the 12C [1] and 13C [2], which motivate targeted future experiments. In particular, a new state of 12C at Ex = 24.4 MeV is strongly populated in the triple α-particle coincidences, while the rarely seen state at Ex = 30.3 MeV is found to be strong in the d+10B decay channel, reinforcing the previous suggestions that it has the exotic 2α+2d molecular structure [3]. Regarding the 13C nucleus, a potentially novel state at Ex = 19.0 MeV is prominently observed in α+ 9Be coincidences and demonstrates a well-defined cluster structure. Lastly, high-spin states in mirror nuclei pairs 9Be-9B, 10Be-10C and 11B-11C populated in the presented measurement are explored.

Preliminary results of a study on triton clustering in neutron-rich 10 Be and 12 Be isotopes through triton ( p,α ) and alpha ( d , 6 Li) transfer are presented. The experiment was performed using the LISE fragmentation beam line of GANIL, making use of the MUGAST-EXOGAM-ZDD setup, which ensures accurate measurement of charged particles and gamma-rays. The experiment, currently under analysis, aims to compare the measured differential cross sections with DWBA calculations performed using microscopic and cluster wave functions derived from models such as AMD or THSR. This ongoing analysis aims to provide quantitative insights into triton clustering in neutron-rich beryllium isotopes. The detection setup used in this experiment is presented, along with preliminary results on the data analysis.

Beryllium-7 (7Be) is widely used as an atmospheric radiotracer due to its short half-life and ease of detection. Its evaluation and forecasting provide valuable insights into atmospheric behavior and environmental processes. This study aimed to develop a robust explanatory and predictive model for 7Be concentrations in Panama using monthly data from 2006 to 2019 provided by the RN50 Station at the University of Panama. This study employed ARIMA models for time series analysis and forecasting, complemented by error metrics such as Root Mean Squared Error (RMSE), Mean Squared Error (MSE), Mean Absolute Error (MAE), and Mean Absolute Percentage Error (MAPE) to assess the accuracy of the results. After verifying data suitability, analyzing series components, and testing stationarity using the Dickey–Fuller test, the SARIMA (2,0,1) (2,1,0) model was identified as optimal. This model successfully forecasted 7Be concentrations for the final five months of 2019, offering a useful tool for understanding airborne particle dynamics in Panama and supporting future applications of 7Be in the study and estimation of soil erosion.

The short-living cosmogenic isotope 7Be, which is produced by cosmic rays in the atmosphere, is often used as a tracer for atmospheric dynamics, with precise and high-resolution measurements covering the recent decades. The long-living isotope 10Be, as measured in polar ice cores with an annual resolution, is a proxy for long-term cosmic-ray variability, whose signal can, however, be distorted by atmospheric transport and deposition that need to be properly modeled to be accounted for. While transport of 7Be can be modeled with high accuracy using the known meteorological fields, atmospheric transport of10Be was typically modeled using case-study-specific simulations or simplified box models based on parameterizations. Thus, there is a need for a realistic model able to simulate atmospheric transport and deposition of beryllium with a focus on polar regions and (inter)annual timescales that is potentially able to operate in a self-consistent mode without the prescribed meteorology. Since measurements of 10Be are extremely laborious and hence scarce, it is difficult to compare model results directly with measurement data. On the other hand, the two beryllium isotopes are believed to have similar transport and deposition properties, being different only in production and lifetime, and thus the results of 7Be transport can be generally applied to 10Be. Here we present a new model, called CCM SOCOL-AERv2-BE, to trace isotopes of 7Be and 10Be in the atmosphere based on the chemistry–climate model (CCM) SOCOL (SOlar Climate Ozone Links), which has been improved by including modules for the production, deposition, and transport of 7Be and 10Be. Production of the isotopes was modeled for both galactic and solar cosmic rays by applying the CRAC (Cosmic Ray Atmospheric Cascade) model. Transport of 7Be was modeled without additional gravitational settling due to the submicron size of the background aerosol particles. An interactive deposition scheme was applied including both wet and dry deposition. Modeling was performed using a full nudging to the meteorological fields for the period of 2002–2008 with a spin-up period of 1996–2001. The modeled concentrations of 7Be in near-ground air were compared with the measured ones at a weekly time resolution in four nearly antipodal high-latitude locations: two in the Northern (Finland and Canada) and two in the Southern (Chile and the Kerguelen Islands) Hemisphere. The model results agree with the measurements in the absolute level within error bars, implying that the production, decay, and lateral deposition are correctly reproduced. The model also correctly reproduces the temporal variability of 7Be concentrations on annual and sub-annual scales, including the presence and absence of the annual cycle in the Northern and Southern Hemisphere, respectively. We also modeled the production and transport of 7Be for a major solar energetic particle event (SPE) on 20 January 2005, which appears insufficient to produce a measurable signal but may serve as a reference event for historically known extreme SPEs. Thus, a new full 3D time-dependent model, based on CCM SOCOL, of 7Be and 10Be atmospheric production, transport, and deposition has been developed. Comparison with real data on the 7Be concentration in the near-ground air validates the model and its accuracy.