Preprints
Filtering by Subject: Physical Sciences and Mathematics
Explaining the Equatorial Pacific Thermocline Response to Climate Change with a Model Hierarchy
Published: 2025-10-17
Subjects: Physical Sciences and Mathematics
Most studies of the equatorial Pacific response to anthropogenic forcing have focused on patterns of sea surface temperature (SST) change. However, similar SST patterns can be consistent with a range of different subsurface responses, each with differing physical and biogeochemical implications. While historical observation and climate model mismatches have been suggested in the literature, we [...]
Instability and atmospheric CO2 anomalies in the recent global carbon cycle
Published: 2025-10-17
Subjects: Physical Sciences and Mathematics
A major instability occurred in the recent global carbon cycle. It manifests as a major CO2 anomaly between 2009 and 2015 that is clearly seen in the residuals from generalized exponential growth, or equivalent quadratic curves through Taylor expansion, or 10-year running means. Our findings contradict recent assertions of the stability of the recent global carbon cycle based on growth rate [...]
Unlocking Gigatonne-scale Carbon Dioxide Removal with strategic tipping point frameworks
Published: 2025-10-16
Subjects: Physical Sciences and Mathematics, Social and Behavioral Sciences
Achieving global climate mitigation requires a rapid acceleration of Carbon Dioxide Removal (CDR) to gigatonne (Gt) scales by 2040. Linear growth in climate solutions is insufficient to reach these targets, but system-change practices and leveraging interventions that trigger self-reinforcing feedbacks ("tipping points"), offer a solution. Enhanced Rock Weathering (ERW) in Brazil is uniquely [...]
Direction-dependent permeability and resistivity of fractured rocks tuned to New Zealand geothermal reservoirs
Published: 2025-10-16
Subjects: Physical Sciences and Mathematics
Understanding permeability in the Earth is vital to optimizing sustainable resource development such as geothermal. In many geothermal fields, permeability is controlled by faults, resulting in high spatial and directional variability, difficult to characterise without costly drilling. Electrical resistivity, however, can be measured from the surface, and like permeability, is sensitive to fluids [...]
Sustainable Groundwater Decisions: Hydro-Economic Model Applications to Irrigation in Contrasting Environmental Conditions
Published: 2025-10-16
Subjects: Agriculture, Earth Sciences, Hydrology, Physical Sciences and Mathematics
Groundwater is important for global agriculture but increasing populations and rising food demand are placing significant pressure on its sustainable use for irrigation. Effective, financially viable irrigation management strategies are urgently needed. This study applies a farm-level hydro-economic model to two contrasting sites: the High Plains Aquifer (HPA), a deep, overexploited, unconfined [...]
Glacier processes from seismic recordings on Sørsdal Glacier, East Antarctica
Published: 2025-10-15
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
A catalogue of seismic events is produced and analysed for Sørsdal Glacier, East Antarctica. Recordings were made using an irregular array of three broadband and eight short-period seismometers, with approximately 3 km aperture, deployed slightly upstream of the expected grounding line during the 2017-18 austral summer. The broadband sensors were used to construct the event catalogue, and the [...]
Eocene lacustrine–volcaniclastic deposits at Aliabad (Central Iran): A possible Proto-basin of the Oligo-Miocene Qom Formation
Published: 2025-10-14
Subjects: Earth Sciences, Geology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
Central Iran hosts intricate Cenozoic successions where the Oligo‑Miocene Qom Formation forms a major hydrocarbon reservoir. The stratigraphic and paleoenvironmental relationship of the Eocene Aliabad deposits to this formation has been controversial. This study integrates stratigraphic logging, petrography, geochemistry (XRD/XRF), and ichnology on 46 thin sections from Aliabad and 157 [...]
Calcareous nannofossil assemblages from El Kef (Tunisia) reveal strong bathymetric controls on Northern Hemisphere recovery patterns following the Cretaceous/Paleogene (K/Pg) mass extinction
Published: 2025-10-12
Subjects: Earth Sciences, Physical Sciences and Mathematics
The Cretaceous/Paleogene (K/Pg) bolide impact ~66 million years ago caused the near-demise of calcareous nannoplankton (coccolithophores): key primary producers and major contributors to the biological pump that exports organic carbon from the surface ocean to the deep sea. Although their mass extinction likely had a profound impact on ecosystem structure and function, the interpretation of early [...]
Dense neural network outperforms other machine learning models for scaling-up lichen cover maps in Eastern Canada
Published: 2025-10-12
Subjects: Environmental Sciences, Natural Resource Economics, Natural Resources Management and Policy, Physical Sciences and Mathematics, Sustainability
Lichen mapping is vital for caribou management plans and sustainable land conservation. Previous studies have used random forest, dense neural network, and convolutional neural network models for mapping lichen coverage. However, to date, it is not clear how these models rank in this task. In this study, these machine learning models were evaluated on their ability to predict lichen percent [...]
Variational numerical-modelling strategies for the simulation of driven free-surface waves
Published: 2025-10-11
Subjects: Engineering, Physical Sciences and Mathematics
A new tool is developed for simulating three-dimensional (3D) water-wave motion using the first fully variational 3D discretisation in space and time of Luke's variational principle (VP), with additional focus on the formation and analysis of extreme waves generated within in-house experimental wavetanks. The resulting ``numerical wavetank'' is able to emulate laboratory sea states in which [...]
Toward Greater Clarity: Reanalyzing Solomon’s Depiction of the Ross Ice Shelf Atmospheric Dynamic
Published: 2025-10-10
Subjects: Education, Physical Sciences and Mathematics, Social and Behavioral Sciences
In the final chapters of The Coldest March: Scott's Fatal Antarctic Expedition, Dr. Susan Solomon analyzes the meteorological conditions surrounding the last blizzard that claimed the lives of Captain Robert Falcon Scott, Dr. Edward Wilson, and Lieutenant Henry Bowers. The book’s conclusion—that the storm could not have lasted ten days and that the men may have chosen to die—warrants close [...]
Curlew 1.0: Spatio-temporal implicit geological modelling with neural fields in python
Published: 2025-10-10
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
We present curlew, an open-source python package for structural geological modelling using neural fields. This modelling framework incorporates various local constraints (value, gradient, orientation and (in)equalities) and tailored global loss functions to ensure data-consistent and geologically realistic predictions. Random Fourier Feature (RFF) encodings are used to improve model convergence [...]
Vegetable supply to Tokyo disrupted by 2023 and 2024 summer heatwaves
Published: 2025-10-09
Subjects: Physical Sciences and Mathematics
Understanding the impacts on urban food supply from extreme climate events is a first step towards building climate-resilient agri-food systems. Here, we report on vegetable supply disruptions in the Tokyo metropolitan area due to the summer heatwaves of 2023 and 2024, using the governmental survey on wholesale market arrival volumes and prices. Fifteen vegetables (broccoli, cabbage, carrot, [...]
No evidence for a 10-m historical tectonic uplift at Mangalia, (Romanian Black Sea coast): Comment on Drăgușin et al. (2025)
Published: 2025-10-09
Subjects: Physical Sciences and Mathematics
Drăgușin et al. (2025) interpreted deposits at Mangalia (Romania) as evidence of a two-phase tectonic event (~14 m subsidence and uplift) during the 18th–19th centuries. Based on multi-proxy data from the same site, we show that this scenario is inconsistent with regional tectonics, stratigraphy, and archaeology. The deposits instead record the gradual infill of a coastal depression episodically [...]
Long-lived topography along rifted margins: Insights from Aparados da Serra escarpment, Southeast Brazil
Published: 2025-10-07
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The Brazilian margin is one of the longest elevated passive margins (EPMs) in the world. However, both the timing of uplift and the long-term evolution of this EPM remain highly debated. In this study, we present a new suite of apatite (U-Th-Sm)/He (AHe) and fission track (AFT) ages for the southern end of the Brazilian EPM, in the Aparados da Serra plateau. Combined with literature data, our [...]