Isotopomer labeling and oxygen dependence of hybrid nitrous oxide production Biogeosciences DOI 10.5194/bg-21-3215-2024 17 July 2024 Nitrous oxide, a potent greenhouse gas, accumulates in regions of the ocean that are low in dissolved oxygen. We used a novel combination of chemical tracers to determine how nitrous oxide is produced in one of these regions, the eastern tropical North Pacific Ocean. Our experiments showed that the two most important sources of nitrous oxide under low-oxygen conditions are denitrification, an anaerobic process, and a novel “hybrid” process performed by ammonia-oxidizing archaea. Read more
Coupled ice–ocean interactions during future retreat of West Antarctic ice streams in the Amundsen Sea sector The Cryosphere DOI 10.5194/tc-18-2653-2024 15 July 2024 A new ice–ocean model simulates future ice sheet evolution in the Amundsen Sea sector of Antarctica. Substantial ice retreat is simulated in all scenarios, with some retreat still occurring even with no future ocean melting. The future of small “pinning points” (islands of ice that contact the seabed) is an important control on this retreat. Ocean melting is crucial in causing these features to go afloat, providing the link by which climate change may affect this sector’s sea level contribution. Read more
Quantum data assimilation: a new approach to solving data assimilation on quantum annealers Nonlinear Processes in Geophysics DOI 10.5194/npg-31-237-2024 12 July 2024 Data assimilation is a crucial component in the Earth science field, enabling the integration of observation data with numerical models. In the context of numerical weather prediction (NWP), data assimilation is particularly vital for improving initial conditions and subsequent predictions. However, the computational demands imposed by conventional approaches, which employ iterative processes to minimize cost functions, pose notable challenges in computational time. The emergence of quantum computing provides promising opportunities to address these computation challenges by harnessing the inherent parallelism and optimization capabilities of quantum annealing machines. Read more
Elevation-dependent warming: observations, models, and energetic mechanisms Weather and Climate Dynamics DOI 10.5194/wcd-5-763-2024 10 July 2024 Observational data and numerical models suggest that, under climate change, elevated land surfaces warm faster than non-elevated ones. Proposed drivers of this “elevation-dependent warming” (EDW) include surface albedo and water vapour feedbacks, the temperature dependence of longwave emission, and aerosols. Yet the relative importance of each proposed mechanism both regionally and at large scales is unclear, highlighting an incomplete physical understanding of EDW. Read more
A downward-counterfactual analysis of flash floods in Germany Natural Hazards and Earth System Sciences DOI 10.5194/nhess-24-2147-2024 8 July 2024 To identify flash flood potential in Germany, we shifted the most extreme rainfall events from the last 22 years systematically across Germany and simulated the consequent runoff reaction. Our results show that almost all areas in Germany have not seen the worst-case scenario of flood peaks within the last 22 years. With a slight spatial change of historical rainfall events, flood peaks of a factor of 2 or more would be achieved for most areas. The results can aid disaster risk management. Read more
The impacts of elevated CO2 on forest growth, mortality, and recovery in the Amazon rainforest Earth System Dynamics DOI 10.5194/esd-15-763-2024 5 July 2024 Elevated CO2 concentration (eCO2) is critical for shaping the future path of forest carbon uptake, while uncertainties remain about concurrent carbon loss. Here, we found that eCO2 might amplify competition-induced carbon loss, while the extent of drought-induced carbon loss hinges on the balance between heightened biomass density and water-saving benefits. This is the first time that such carbon loss responses to ongoing climate change have been quantified separately over the Amazon rainforest. Read more
Evaluation of forecasts by a global data-driven weather model with and without probabilistic post-processing at Norwegian stations Nonlinear Processes in Geophysics DOI 10.5194/npg-31-247-2024 3 July 2024 During the last 2 years, tremendous progress has been made in global data-driven weather models trained on reanalysis data. In this study, the Pangu-Weather model is compared to several numerical weather prediction models with and without probabilistic post-processing for temperature and wind speed forecasting. The results confirm that global data-driven models are promising for operational weather forecasting and that post-processing can improve these forecasts considerably. Read more
Opinion: Optimizing climate models with process knowledge, resolution, and artificial intelligence Atmospheric Chemistry and Physics DOI 10.5194/acp-24-7041-2024 1 July 2024 Climate models are crucial for predicting climate change in detail. This paper proposes a balanced approach to improving their accuracy by combining traditional process-based methods with modern artificial intelligence (AI) techniques while maximizing the resolution to allow for ensemble simulations. The authors propose using AI to learn from both observational and simulated data while incorporating existing physical knowledge to reduce data demands and improve climate prediction reliability. Read more
600 years of wine must quality and April to August temperatures in western Europe 1420–2019 Climate of the Past DOI 10.5194/cp-20-1387-2024 28 June 2024 This bottle of Riesling from the traditional Bassermann Jordan winery in Deidesheim (Germany) is a relic of the premium wine harvested in 1811. It was named “Comet Wine” after the bright comet that year. The study shows that wine quality can be used to infer summer weather conditions over the past 600 years. After rainy summers with cold winds, wines turned sour, while long periods of high pressure led to excellent qualities. Since 1990, only good wines have been produced due to rapid warming. Read more
Impact of Hurricane Irma on coral reef sediment redistribution at Looe Key Reef, Florida, USA Ocean Science DOI 10.5194/os-20-661-2024 26 June 2024 Global understanding of storm-driven sediment transport along coral reefs and its impact on species and habitats is limited. Measurement of seafloor elevation and volume change due to a category 4 hurricane showed rapid burial of coral reef habitats and migration of large seafloor features due to the storm. Post-storm erosion rates were 2 orders of magnitude greater than historical rates, indicating areas of seafloor instability that could be less suitable for restoration of benthic species. Read more