Decadal changes in phytoplankton functional composition in the Eastern English Channel: possible upcoming major effects of climate change Ocean Science DOI 10.5194/os-21-679-2025 24 March 2025 This study provides the first assessment of decadal changes in the whole phytoplankton community, addressed by flow cytometry, in the highly productive waters of the Strait of Dover. A significant surface seawater temperature increase of 1°C, associated with an important change in the nutrient concentration and balance, has triggered a change in the phytoplankton communities, characterized by a higher total abundance and an increasing proportion of the smallest cells (picroeukaryotes and picocyanobacteria). Read more
Reconstruction of Holocene and Last Interglacial vegetation dynamics and wildfire activity in southern Siberia Climate of the Past DOI 10.5194/cp-21-661-2025 21 March 2025 We analyse a southern Siberian stalagmite to reconstruct soil respiration, wildfire, and vegetation trends during the Last Interglacial (LIG) (124.1–118.8 ka) and the Holocene (10–0 ka). Wildfires were more prevalent during the LIG than the Holocene and were supported by fire-prone species, low soil respiration, and a greater difference between summer and winter temperature. We show that vegetation type and summer/winter temperature contrast are strong drivers of Siberian wildfires. Read more
Modelled surface climate response to effusive Icelandic volcanic eruptions: sensitivity to season and size Atmospheric Chemistry and Physics DOI 10.5194/acp-25-2989-2025 19 March 2025 We use an Earth system model to systematically investigate the climate response to high-latitude effusive volcanic eruptions as a function of eruption season and size, with a focus on the Arctic. We find that different seasons strongly modulate the climate response, with Arctic surface warming observed in winter and cooling in summer. Additionally, as eruptions increase in terms of sulfur dioxide emissions, the climate response becomes increasingly insensitive to variations in emission strength. Read more
Meteorological ingredients of heavy precipitation and subsequent lake-filling episodes in the northwestern Sahara Hydrology and Earth System Sciences DOI 10.5194/hess-29-1395-2025 17 March 2025 The Sahara was wetter in the past and may become wetter in the future. Lake remnants are evidence of the desert’s wetter past. If the Sahara gets wetter in the future, these lakes may serve as a water resource. However, it is unclear how these lakes get filled and how moisture is carried into the desert and converted into rain in the first place. Therefore, we examine processes currently leading to the filling of a dry lake in the Sahara, which can help assess future water availability. Read more
Assessing Lagrangian coherence in atmospheric blocking Nonlinear Processes in Geophysics DOI 10.5194/npg-32-51-2025 28 February 2025 We identify spatially coherent air streams into atmospheric blockings, which are important weather phenomena. By adapting mathematical methods to the atmosphere, we confirm previous findings. Our work shows that spatially coherent air streams featuring cloud formation correlate with strengthening of the blocking. The developed framework also allows for statements about the spatial behavior of the air parcels as a whole and indicates that blockings reduce the dispersion of the air parcels. Read more
Evaluating F10.7 and F30 radio fluxes as long-term solar proxies of energy deposition in the thermosphere Annales Geophysicae DOI 10.5194/angeo-43-175-2025 28 February 2025 We study how well the F10.7 and F30 solar radio fluxes have represented solar energy input in the thermosphere in the last 60 years. We found that increased saturation of radio fluxes at recent solar minima leads to an overestimation of solar energy, which changes the relation between thermospheric parameters and F10.7, but this is not an issue for F30 because of a relative increase in F30 with respect to F10.7. This explains why F30 has been found to represent solar energy better than F10.7. Read more
CH-RUN: a deep-learning-based spatially contiguous runoff reconstruction for Switzerland Hydrology and Earth System Sciences DOI 10.5194/hess-29-1061-2025 27 February 2025 This study reconstructs daily runoff in Switzerland (1962–2023) using a deep-learning model, providing a spatially contiguous dataset on a medium-sized catchment grid. The model outperforms traditional hydrological methods, revealing shifts in Swiss water resources, including more frequent dry years and declining summer runoff. The reconstruction is publicly available. RUN: a deep-learning-based spatially contiguous runoff reconstruction for Switzerland">Read more
Sensitivity of tropical orographic precipitation to wind speed with implications for future projections Weather and Climate Dynamics DOI 10.5194/wcd-6-231-2025 27 February 2025 Rainfall in mountainous regions constitutes an important source of freshwater in the tropics. Yet how it will change with global warming remains an open question. Here, we reveal a strong sensitivity of this rainfall to the speed of prevailing winds. This relationship, validated by theory, simulations, and observational data, suggests that regional wind shifts will significantly influence future rainfall changes in the tropics. Read more
Opinion: Why all emergent constraints are wrong but some are useful – a machine learning perspective Atmospheric Chemistry and Physics DOI 10.5194/acp-25-2365-2025 26 February 2025 In our article, we review uncertainties in global climate change projections and current methods using Earth observations as constraints, which is crucial for climate risk assessments and for informing society. We then discuss how machine learning can advance the field, discussing recent work that provides potentially stronger and more robust links between observed data and future climate projections. We further discuss the challenges of applying machine learning to climate science. Read more
Brief communication: Sea-level projections, adaptation planning, and actionable science The Cryosphere DOI 10.5194/tc-19-793-2025 25 February 2025 As communities try to adapt to climate change, they look for “actionable science” that can inform decision-making. There are risks in relying on novel results that are not yet accepted by the science community. We propose a practical criterion for determining which scientific claims are actionable. We show how premature acceptance of sea-level-rise predictions can lead to confusion and backtracking, and we suggest best practices for communication between scientists and adaptation planners. Read more