Graphical representation of global water models Geoscientific Model Development DOI 10.5194/gmd-18-2409-2025 23 April 2025 Global water models contribute to the evaluation of important natural and societal issues but are – as all models – simplified representation of reality. So, there are many ways to calculate the water fluxes and storages. This paper presents a visualization of 16 global water models using a standardized visualization and the pathway towards this common understanding. Next to academic education purposes, we envisage that these diagrams will help researchers, model developers, and data users. Read more
The energy-efficient reductive tricarboxylic acid cycle drives carbon uptake and transfer to higher trophic levels within the Kueishantao shallow-water hydrothermal system Biogeosciences DOI 10.5194/bg-22-1853-2025 15 April 2025 In acidic hot springs off Kueishantao, Campylobacteria fix CO2 by using the reductive tricarboxylic acid (rTCA) cycle, causing them to have an isotopically heavier biomass. Here, we report extremely low isotopic fractionation (of almost 0 ‰), which has never been reported in environmental samples. Moreover, the crab Xenograpsus testudinatus relies up to 34 % on campylobacterial biomass, highlighting the dependency of complex life on microscopic Bacteria in harsh environments. Read more
High-resolution Holocene record based on detailed tephrochronology from Torfdalsvatn, north Iceland, reveals natural and anthropogenic impacts on terrestrial and aquatic environments Climate of the Past DOI 10.5194/cp-21-795-2025 11 April 2025 Questions remain about the past climate in Iceland, including the relative impacts of natural and human factors on vegetation change and soil erosion. We present a sub-centennial-scale record of landscape and algal productivity from a lake in north Iceland. Along with a high-resolution tephra age constraint that covers the last ∼ 12 000 years, our record provides an environmental template for the region and novel insight into the sensitivity of the Icelandic ecosystem to natural and human impacts. Read more
Inter-model differences in 21st century glacier runoff for the world's major river basins The Cryosphere DOI 10.5194/tc-19-1491-2025 8 April 2025 Glacier models have historically been used to understand glacier melt’s contribution to sea level rise. The capacity to project seasonal glacier runoff is a relatively recent development for these models. In this study we provide the first model intercomparison of runoff projections for the glacier evolution models capable of simulating future runoff globally. We compare model projections from 2000 to 2100 for all major river basins larger than 3000 km2 with over 30 km2 of initial glacier cover. Read more
Stratospheric residence time and the lifetime of volcanic stratospheric aerosols Atmospheric Chemistry and Physics DOI 10.5194/acp-25-3821-2025 4 April 2025 The climate impact of volcanic eruptions depends in part on how long aerosols spend in the stratosphere. We develop a conceptual model for stratospheric aerosol lifetime in terms of production and decay timescales, as well as a lag between injection and decay. We find residence time depends strongly on injection height in the lower stratosphere. We show that the lifetime of stratospheric aerosol from the 1991 Pinatubo eruption is around 22 months, significantly longer than is commonly reported. Read more
Incorporating science communication and bicultural knowledge in teaching a blended volcanology course Geoscience Communication DOI 10.5194/gc-8-107-2025 3 April 2025 We added more science communication activities and cultural content from Māori cultural experts in a course that combines online interactive virtual fieldtrip content with reflective workshops, laboratory sessions, and fieldwork, to reflect a need for these skills in the Aotearoa NZ workforce. Students mentioned science communication and cultural competence more when responding to a survey question regarding What they learnt?, and they highlighted the importance that these skills might have for themselves. Read more
Pristine oceans are a significant source of uncertainty in quantifying global cloud condensation nuclei Atmospheric Chemistry and Physics DOI 10.5194/acp-25-3841-2025 2 April 2025 Aerosol particles in the atmosphere increase cloud reflectivity, thereby cooling the Earth. Accurate global measurements of these particles are crucial for estimating this cooling effect. This study compares and harmonizes two newly developed global aerosol datasets, offering insights for their future use and refinement. We identify pristine oceans as a significant source of uncertainty in the datasets and, therefore, in quantifying the role of aerosols in Earth's climate. Read more
Potential for equation discovery with AI in the climate sciences Earth System Dynamics DOI 10.5194/esd-16-475-2025 31 March 2025 AI is impacting science, providing key data insights, but most algorithms are statistical requiring cautious "out-of-sample" extrapolation. Yet climate research concerns predicting future climatic states. We consider a new method of AI-led equation discovery. Equations offer process interpretation and more robust predictions. We recommend this method for climate analysis, suggesting illustrative application to atmospheric convection, land–atmosphere CO2 flux, and global ocean circulation models. Read more
Composite model-based estimate of the ocean carbon sink from 1959 to 2022 Biogeosciences DOI 10.5194/bg-22-1631-2025 28 March 2025 The ocean is a major natural carbon sink. Despite its importance, estimates of the ocean carbon sink remain uncertain. Here, I present a hybrid model estimate of the ocean carbon sink from 1959 to 2022. By combining ocean models in hindcast mode and Earth system models, I keep the strength of each approach and remove the respective weaknesses. This composite model estimate is similar in magnitude to the best estimate of the Global Carbon Budget but 70 % less uncertain. Read more
Modulation of the northern polar vortex by the Hunga Tonga–Hunga Ha'apai eruption and the associated surface response Atmospheric Chemistry and Physics DOI 10.5194/acp-25-3623-2025 28 March 2025 In January 2022, the Hunga Tonga–Hunga Ha'apai (HTHH) volcano erupted, sending massive amounts of water vapour into the atmosphere. This event had a significant impact on stratospheric and lower-mesospheric chemical composition. Two years later, stratospheric conditions were disturbed during so-called sudden stratospheric warmings. Here we simulate a novel pathway by which this water-rich eruption may have contributed to conditions during these events and consequently impacted the surface climate. Read more