Recent lbnl_ees items

Wind stilling shapes grassland water use efficiency by enhancing soil moisture retention

Tue, 4 Aug 2026 00:00:00 +0000

Covering more than 40% of Earth's vegetated surface, grasslands critically regulate terrestrial carbon and water cycles. Their ecosystem water use efficiency (WUE_eco), the ratio of carbon uptake to water loss, governs drought resilience in these water-limited ecosystems. While global terrestrial wind speed declined substantially from the 1960s to 2000s followed by a recovery in the subsequent decade, the extent and mechanisms of its influence on grassland WUE_eco remain poorly understood. Using site observations, satellite data, Earth system models, and wind manipulation experiments, we found a consistent negative sensitivity of grassland WUE_eco to wind speed. Mechanistically, declining winds reduce evaporative water loss, improve soil moisture, and promote stomatal opening, thereby enhancing carbon uptake. Wind speed changes accounted for 7.7 to 25.7% of WUE_eco increases under historical and future climates, making wind the second most...

Soil fertility controls on tropical forest productivity and mortality: synthesis and roadmap

Thu, 30 Jul 2026 00:00:00 +0000

Tropical forests are highly diverse and productive ecosystems and store nearly 60% of vegetation biomass. Across the tropics, forests span large gradients of soil fertility, from vast regions situated on highly weathered, ancient geological formations to others on young, nutrient-rich landscapes. Tropical forest productivity, mortality, and biomass all vary systematically across these gradients in soil fertility. Aboveground forest productivity tends to increase with higher soil fertility, while counterintuitively, aboveground biomass does not increase proportionally. This disconnect is likely due to coinciding increases in mortality with higher soil fertility. However, we know relatively little about the mechanisms underlying how soil fertility regulates productivity or mortality - two critical determinants of forest biomass - and even less about how these relationships will shape tropical forest responses to global change. Here, we present a mechanistic framework for understanding...

ENVnet provides a global molecular resource of dissolved organic matter

Thu, 30 Jul 2026 00:00:00 +0000

Dissolved organic matter (DOM) is a central component of Earth’s carbon cycle and one of the planet’s most chemically diverse pools, yet the molecular structures of its constituents remain largely unresolved. This limitation has hindered our ability to link DOM composition to microbial processes and ecosystem function. Here we present ENVnet, a global molecular repository built from tandem mass spectrometry data collected across 13 terrestrial and aquatic environment types, including 419 newly generated samples that expand publicly available DOM metabolomics data and cover previously underrepresented environments. By computationally deconvolving chimeric mass spectra, a longstanding challenge in environmental metabolomics, we recover high-quality fragmentation data for >22,000 distinct molecular features (defined by a specific precursor mass and fragmentation pattern). Using ENVnet, we uncover conserved and environment-specific molecular patterns in DOM composition and underlying...

The Energy Exascale Earth System Model Version 3: 2. Overview of the Coupled System

Wed, 29 Jul 2026 00:00:00 +0000

Abstract The Energy Exascale Earth System Model version 3 (E3SMv3) represents the latest advancement in Earth system modeling developed by the U.S. Department of Energy (DOE). Building upon previous versions, E3SMv3 introduces significant updates across its coupled components to enhance capability and improve fidelity. The atmosphere component incorporates advancements in chemistry, aerosol‐cloud interactions, convection, and microphysics. The ocean features a new time‐stepping scheme and a higher‐resolution unstructured mesh with sub‐ice‐shelf cavities, while the sea ice model integrates advanced snow and ice physics for more realistic cryospheric simulations. The land model introduces prognostic vegetation dynamics and a new sub‐grid topographic treatment of solar radiation. A new tri‐grid configuration harmonizes the horizontal grids of the land and river components for improved process coupling. It is enabled by a new non‐linear remapping between the atmosphere and land. E3SMv3...

Flux Footprints: A Critical Link to Bridge Eddy‐Covariance Measurements With Models, Remote Sensing, and Other Observations

Tue, 28 Jul 2026 00:00:00 +0000

Global networks of eddy-covariance flux towers play a pivotal role in enhancing our predictive understanding of carbon and water cycling of biological systems in response to regional and global environmental change. Despite their broad application in numerous studies, the spatial aspects of the flux measurements have often been ignored or treated ambiguously, thereby remaining a primary source of uncertainty. The area contributing to the flux-referred to as the flux footprint-varies over time depending on wind direction, atmospheric turbulence, effective measurement heights, surface characteristics, and mesoscale forcings. The footprint dynamics, along with underlying source-sink heterogeneity, lead to spatial and temporal variability in the sensed fluxes, complicating the interpretation of flux data and their integration with a range of observations and models. This article addresses this critical link by reviewing the most up-to-date research, identifying knowledge gaps and...

LocatingUndocumentedWells Using Historical Oil andGas Exploration Maps: A Case Study in Osage County, Oklahoma

Tue, 28 Jul 2026 00:00:00 +0000

Undocumented oil and gas wells lack reliable information about their locations and characteristics, making them difficult to identify. These wells can result in unanticipated delays and costs in the development of nearby surface and subsurface resources, and, if improperly plugged, can cause contamination. This study leverages historical petroleum exploration maps to locate such wells, focusing on Osage County, Oklahoma. Two sets of early 20th century oil and gas exploration maps by the United States Geological Survey were georeferenced and analyzed using a computer vision model to detect well symbols. The locations of detected wells were compared to the location of known wells in the database from the Bureau of Indian Affairs Osage Agency to identify potential undocumented wells. The analysis yielded over 500 potential undocumented wells, with dry holes constituting the largest fraction. Field verification confirmed the presence of some undocumented wells. Comparison with prior...

Complex Electrical Conductivity of a Single‐Fractured Rock: Fracture‐and‐Matrix Coupling Mechanism and Aperture Size Predictions

Wed, 22 Jul 2026 00:00:00 +0000

Abstract Fractured rocks play a crucial role in myriad natural and engineered systems, including Earth's critical zone, oil/gas/geothermal reservoirs, and geological CO 2 /H 2 /waste storage systems. While complex electrical conductivity is extensively used to estimate the pore and grain sizes of conventional porous rocks and soils, it is rarely used to predict the aperture size of fractured rocks and this remains poorly understood. Here, integrating theory, simulations, and experiments, we show that under external fields, fractured rocks follow the fracture‐and‐matrix coupling to make the bulk complex conductivity non‐linear with respect to water conductivity. We find that the relaxation time and quadrature conductivity for porous media do not apply to fractured rocks, but, instead, reasonably accurate predictions of aperture size can be made based on the true formation factor. This study unravels the fundamental mechanism governing conduction and polarization of fractured rocks...

Divergent carbon use efficiency-growth rate tradeoff in popular biological growth models

Wed, 22 Jul 2026 00:00:00 +0000

Abstract. Carbon use efficiency (CUE) is an important trait emerging from processes regulating biological growth. CUE can be computed either based on the growth of structural biomass or total biomass divided by substrate uptake rate. Nonequilibrium thermodynamics and observations suggest that, for an exponentially growing population of cells, structural biomass CUE should first increase, then peak, and finally decrease with specific growth rate; meanwhile, total biomass CUE increases asymptotically with specific growth rate. We compared predictions from six popular models that are often used for plant and microbial growth in existing ecosystem models. We found that, for an exponentially growing population of biological cells, (1) the source-driven Pirt and Compromise models predict that structural biomass CUE increase asymptotically with growth rate; (2) the apparent sink-driven modified Droop model predicts that structural biomass CUE decreases with growth rate; and (3) the sink-driven...

Warming and snow loss increase reliance on old groundwater in a Colorado River headwater

Tue, 21 Jul 2026 00:00:00 +0000

Atmospheric warming is reducing snowpack, with uncertain effects on mountainous streamflow, a crucial water resource. Despite limited historical observations of groundwater–streamflow interactions above 2,500 m, new measurements in the Upper Colorado River headwaters indicate declining groundwater storage that is dated decades to millennia old. Here we use integrated hydrologic modelling spanning water years 2015–2021 to determine whether the loss of old-age groundwater buffers streamflow during low-snow years and whether that loss is exacerbated with warming. Results show that old-groundwater contributions to streams remain relatively steady through time, unlike the more variable contributions from young groundwater. Numerical experiments of increased surface air temperatures (+2.5 °C and +4 °C) increase rain–snow fractions and evapotranspiration and decrease runoff ratio by 2–3% per degree Celsius increase. As streamflow declines with warming, the age of groundwater supporting...

A Statistician’s Overview of Physics-Informed Neural Networks for Spatio-Temporal Data

Thu, 16 Jul 2026 00:00:00 +0000

The recent success of deep neural network models with physical constraints (so-called, Physics-Informed Neural Networks, PINNs) has led to renewed interest in the incorporation of mechanistic information in predictive models. Statisticians and others have long been interested in this problem, which has led to several practical and innovative solutions dating back decades. In this overview, we focus on the problem of data-driven prediction and inference of dynamic spatio-temporal processes that include mechanistic information, such as would be available from partial differential equations, with a strong focus on the quantification of uncertainty associated with data, process, and parameters. We give a brief review of several paradigms and focus our attention on Bayesian implementations given they naturally accommodate uncertainty quantification. We then show that it is straight-forward to include the Bayesian PINN (B-PINN) within the Bayesian hierarchical model (BHM) framework...

Regional Earthquake Ground Motion Simulations for Southern California With EQSIM: Insights From the 2008 Chino Hills, 2024 Highland Park, and 2021 Carson Earthquakes

Thu, 16 Jul 2026 00:00:00 +0000

This study presents physics‐based, 3D simulations using the EQSIM framework for several earthquakes in the Los Angeles region. The primary objective was to assess the ability of deterministic physics‐based ground motion simulations to reproduce the observed motions from historical events. The selected events included the 5.4 2008 Chino Hills, the 4.4 2024 Highland Park, and the 4.3 2021 Carson events. The simulated motions were evaluated by comparing the recorded and simulated seismograms, as well as the Fourier amplitude spectra, across multiple seismic stations. The SCEC 3D velocity model, CVM‐S4.26.M01, was used to represent the regional geology, and ground motion simulations were carried out with a resolution of up to 5 Hz. The results indicate that the simulated motions captured the recorded motions up to approximately 4 Hz. While careful iterations regarding source parameters and corner frequencies were required, and, for the case of the Highland Park event, some of the...

Improving energy efficiency while reducing anthropogenic heat from buildings: how retrofits influence the building stock and urban microclimate in Los Angeles

Thu, 16 Jul 2026 00:00:00 +0000

Anthropogenic heat (AH) from buildings contributes to urban overheating, especially during heat waves, yet building retrofit studies usually evaluate energy savings without assessing impacts on AH. This study quantifies how common building retrofit measures affect both building energy use and AH emissions across the City of Los Angeles. Using a bottom-up urban building energy modeling framework coupled with high-resolution local weather from the Weather Research and Forecasting model with Building Effect Parameterization (WRF-BEP), we evaluate eleven retrofit measures and two multi-measure retrofit packages. HVAC and LED lighting retrofits provide the largest city-wide annual site energy savings, while roof coating is most effective for reducing AH. A package optimized for energy savings reduces summer site energy use by about 32% (2.3 TWh), while a package incorporating AH-focused measures reduces the total AH by over 50% (137 PJ) with minimal difference in energy savings. The...

Evaluating Soil Carbon Models for Sub‐Saharan Africa: Revealing Knowledge Gaps in Subtropical and Tropical Soil Biogeochemistry

Tue, 14 Jul 2026 00:00:00 +0000

Abstract Process‐based soil carbon (C) models are increasingly used to project regional and global C cycle responses to climate change. However, the development and evaluation of these models has largely focused on temperate regions of North America and Europe. This geographic bias raises a critical question: Do these models capture generalizable mechanisms that can be applied to underrepresented pedological regions or encode processes specific to their developmental context? We evaluated three process‐based models—Century, Millennial, and MIMICS—across 777 topsoil samples spanning the climate and pedological diversity of sub‐Saharan Africa. Despite their differences in mechanistic detail, all three models performed similarly (adjusted R 2 = 0.09–0.18) in predicting soil organic carbon (SOC) stocks. Using random forest algorithms trained on observed and modeled SOC data, we identified divergences between the drivers of SOC. All three models overemphasized net primary...

Long-term warming of a forest soil reduces microbial biomass and its carbon and nitrogen use efficiencies

Tue, 14 Jul 2026 00:00:00 +0000

Global warming impacts biogeochemical cycles in terrestrial ecosystems, but it is still unclear how the simultaneous cycling of carbon (C) and nitrogen (N) in soils could be affected in the longer-term. Here, we evaluated how 14 years of soil warming (+4 °C) affected the soil C and N cycle across different soil depths and seasons in a temperate mountain forest. We used H2 18O incorporation into DNA and 15N isotope pool dilution techniques to determine gross rates of C and N transformation processes. Our data showed different warming effects on soil C and N cycling, and these were consistent across soil depths and seasons. Warming decreased microbial biomass C (−22%), but at the same time increased microbial biomass-specific growth (+25%) and respiration (+39%), the potential activity of β-glucosidase (+31%), and microbial turnover (+14%). Warming reduced gross rates of protein depolymerization (−19%), but stimulated gross N mineralization (+63%) and the potential activities...

Congo Basin Carbon Cycle Responses to Global Change

Tue, 14 Jul 2026 00:00:00 +0000

The Congo Basin and its contiguous forests harbor globally significant carbon stocks, estimated at 65 gigatons of C (GtC) above and belowground. Despite rising temperatures and intensifying droughts, they have remained a carbon sink, albeit weak: 0.26-0.50 GtC yr.^-1 carbon uptake since 1980. However, these forests' carbon stocks and fluxes, including gross primary productivity, respiration, net primary productivity, and riverine carbon transport, remain poorly quantified. This limits understanding of the region's role in the global carbon cycle, its vulnerability to environmental change, and its potential as a long-term carbon sink. We review and quantify Congo Basin and contiguous forest carbon stocks and fluxes and synthesize the current knowledge on how key global change drivers shape the region's carbon cycle. We find limited responses to long-term precipitation variability, but declining stocks and fluxes in response to long-term and increasing temperature and...

Increased Belowground Carbon Allocation Reduces Soil Carbon Losses Under Long‐Term Warming

Tue, 14 Jul 2026 00:00:00 +0000

The response of the carbon cycle in forests to global warming could lead to a positive climate feedback if warming accelerates the mineralization of soil organic carbon (SOC), thereby causing net emissions of CO₂ into the atmosphere. In Europe, carbon-rich alpine forest soils could be particularly affected by global warming, as a greater rise in temperature is expected in this region than the global average. Here we show that nearly two decades of experimental soil warming (+4°C during the snow-free seasons) in a mountain forest in the Northern Limestone Alps significantly (~13% per 1°C warming) and persistently (no change in response over 18 years) increased soil CO₂ effluxes. The SOC stocks in the warmed plots decreased compared to controls, yet non-significantly, and quantitatively much less than the surplus carbon outflux from warmed soil suggests. We attribute the increase in soil CO₂ efflux primarily to stimulation of root respiration, which...

Optical and spin properties of nitrogen vacancy centers in diamond formed along high-energy heavy ion tracks

Tue, 30 Jun 2026 00:00:00 +0000

Exposure of matter to high-energy heavy ions induces defects along the ion trajectories through electronic and nuclear energy loss processes. Defects, including color centers, can recombine or form along latent damage tracks in semiconductors. Latent tracks in diamond were only recently observed. Here we report on color center formation in nitrogen-doped diamond along the latent tracks of 1 GeV gold and uranium ions. We optically observe direct formation of single vacancy related color centers (GR1-centers) along the tracks. Mobile vacancies can form NV-centers with native nitrogen atoms during thermal annealing. Molecular dynamics simulations show that isolated vacancies and vacancy clusters form through electronic stopping processes along ion trajectories. Moreover, by using 1 GeV Au ions with a dilute fluence, we create individually isolated quasi-1D chains of NV-centers, which appear as isolated bright luminescence strings and present competitive electron spin properties compared...

Toward the performance assessment of advanced nuclear waste forms: temperature dependence of lanthanide borosilicate glass dissolution

Mon, 29 Jun 2026 00:00:00 +0000

Lanthanide borosilicate (LaBS) glasses are among the most promising waste forms for the immobilization of high-level radioactive waste generated from advanced nuclear fuel cycles. However, the temperature dependence of their dissolution kinetics remains poorly understood and constrained, limiting the integration of these materials into established performance assessment models. Here, we investigate the dissolution behavior of the legacy AmCm2-19 LaBS glass and the benchmark alkali aluminoborosilicate ISG-1 in deionized water between 50 °C and 250 °C using ASTM C1285 (Product Consistency Test-B) protocols. For AmCm2-19 LaBS glass, normalized elemental release rates for boron and silicon increase with temperature before plateauing near 150 °C, consistent with solubility-limited behavior. From data obtained at 50 °C and 100 °C, Arrhenius analysis yields activation energies of Ea(B) = 24.8 ± 0.3 kJ mol⁻¹ and Ea(Si) = 14.4 ± 0.2 kJ mol⁻¹, similar or slightly lower than those previously...

Learning earthquake ground motions via conditional generative modeling

Fri, 26 Jun 2026 00:00:00 +0000

Predicting high-fidelity ground motions for future earthquakes is crucial for seismic hazard assessment and infrastructure resilience. Conventional empirical simulations suffer from sparse sensor distribution and geographically localized earthquake locations, while physics-based methods are computationally intensive and require accurate representations of Earth structures and earthquake sources. We propose an artificial intelligence (AI) spectrogram generator, Conditional Generative Modeling for Ground Motion (CGM-GM). CGM-GM leverages earthquake magnitudes and geographic coordinates of earthquakes and sensors as inputs, when postprocessed with phase information, capturing spatially continuous Fourier amplitude spectra (FAS) as well as properties such as P and S arrivals, and waveform durations, without explicit physics constraints. This is achieved through a probabilistic autoencoder that extracts latent distributions in the time-frequency domain and variational sequential models...

The Role of Tropical Cyclone—Ocean Interactions in Future Changes in Hurricane Katrina

Tue, 23 Jun 2026 00:00:00 +0000

Abstract Tropical cyclone (TC) intensity and precipitation are projected to increase in the future. However, some projections are based on atmosphere‐only models in which sea surface temperatures are prescribed, whereas projections based on global atmosphere‐ocean coupled models can be subject to long‐term ocean biases. We investigated the role of TC‐ocean interactions in future changes in TC intensity and precipitation in Hurricane Katrina. We performed four‐member ensembles using convection‐permitting atmosphere‐only and atmosphere‐ocean regional models for the historical climate and four future climates. We found that although future TC intensity and precipitation increased regardless of ocean coupling, ocean coupling dampened the future minimum sea‐level pressure decrease by half and amplified future precipitation scaling. Compared to future changes in upper‐ocean temperature, changes in salinity contributed little to future changes in TC intensity. This study highlights the...

Unprecedented Shifts in Hydrology Are Emerging Across California's Critical Basins: An Evaluation From 0.5 to 3.5°C

Thu, 18 Jun 2026 00:00:00 +0000

Abstract With advances in climate models and downscaling techniques, stakeholders anticipate high‐resolution analysis to inform regional to local changes in water management. Here, we produce hydrologic projections from an ensemble of Earth System Models (ESMs) that were selected and downscaled to support California's 5th Climate Assessment. An ensemble of 19 ESMs was downscaled to a 3‐km resolution across California using a statistical‐dynamical downscaling approach and subsequently run through two calibrated hydrology models. Although California has been extensively studied in the context of climate change, we provide the first evaluation of the warming thresholds at which hydroclimate metrics demonstrate statistically significant shifts. We show that present‐day to near‐term warming levels in Klamath and Northern Sierra Nevada basins, which serve as a critical source of water for California, show statistically significant decreases in snowfall and peak snowpack and associated...

Seismic Velocity Monitoring Reveals Complex Magma Transport Dynamics at Kīlauea Volcano Prior to the 2018 Eruption

Tue, 16 Jun 2026 00:00:00 +0000

Abstract Magma and pressure transport between Kīlauea's summit reservoirs and along its East Rift Zone (ERZ) are dynamic even in the absence of surface eruptions. However, these processes do not always produce surface manifestations and may sometimes elude detection by current geological and geodetic monitoring. Here we monitor subsurface seismic velocity changes across Kīlauea's system from 2013 to 2018 and integrate these observations with concurrent measurements of ground deformation and lava lake elevation. We corroborate years‐long seismic velocity decreases around the summit caldera, which are particularly pronounced at southern stations, consistent with sustained pressurization of the South Caldera reservoir (SCR) from a deep magma supply. Following the 2015 summit intrusion, accelerated rates of velocity decrease, summit inflation, and lava lake rise suggest an increased magma supply to the SCR. Notably, we identify an anomalous 7‐month period (late 2016–mid 2017) of disrupted...

Crustal Characterization of the Hengill Geothermal Fields: Insights From Isotropic and Anisotropic Seismic Noise Imaging Using a 500‐Node Array

Tue, 16 Jun 2026 00:00:00 +0000

Abstract The Hengill volcano and its associated geothermal fields represent Iceland's most productive harnessed high‐temperature geothermal fields, where resources are fueled by cooling magmatic intrusions connected to three volcanic systems. The crustal structure in this area is highly heterogeneous and shaped by the intricate interplay between tectonic forces and magmatic/hydrothermal activities. This complexity makes detailed subsurface characterization challenging. In this study, we aim to push the current resolution limits using a 500‐node temporary seismic array and perform an isotropic and, for the first time, radially‐anisotropic velocity model of the area. The high‐resolution isotropic velocity model reveals the characteristic N30ºE fissure swarm that crosses the area within the top 500 m and outlines a deep‐seated low‐velocity body composed of cooling magmatic intrusions at 5 km depth. This deeper body is located near the eastern part of the three volcanic...

Enhanced inner core fine-scale heterogeneity towards Earth’s centre

Tue, 16 Jun 2026 00:00:00 +0000

Earth’s inner core acquires texture as it solidifies within the fluid outer core. The size, shape and orientation of the mostly iron grains making up the texture record the growth of the inner core and may evolve over geologic time in response to geodynamical forces and torques1. Seismic waves from earthquakes can be used to image the texture, or fabric, of the inner core and gain insight into the history and evolution of Earth’s core2–6. Here, we observe and model seismic energy backscattered from the fine-scale (less than 10 km) heterogeneities7 that constitute inner core fabric at larger scales. We use a novel dataset created from a global array of small-aperture seismic arrays—designed to detect tiny signals from underground nuclear explosions—to create a three-dimensional model of inner core fine-scale heterogeneity. Our model shows that inner core scattering is ubiquitous, existing across all sampled longitudes and latitudes, and that it substantially increases in strength...

Extreme seismic anisotropy indicates shallow accumulation of magmatic sills beneath Yellowstone caldera

Tue, 16 Jun 2026 00:00:00 +0000

Understanding the distribution and mobility of crystal mushes within modern magmatic systems is crucial to volcanic hazard assessments as distinct pockets of mobile magma may become interconnected and lead to melt accumulation on shorter time scales than magma that is broadly distributed in a homogeneous mush. Here, we reveal that Yellowstone's upper-crustal magma reservoir in the top 20 km is heterogeneous in both melt concentration and texture. We exploit ambient noise in an unprecedented dense temporary seismic network to jointly constrain vertically- and horizontally-polarized shear wave speeds to create enhanced 3D isotropic and anisotropic shear velocity models. Our models show an exceptionally low-velocity (>20% reduction) layer 4–7 km beneath the surface, situated near the top of the reservoir previously-imaged by earthquake P-wave tomography. The presence of strong radial anisotropy (20%) within this layer indicates the uppermost portion of the modern Yellowstone reservoir...

The effect of relative humidity and temperature on the response of stomatal conductance to vapor pressure deficit in tropical trees

Tue, 16 Jun 2026 00:00:00 +0000

Understanding how leaf gas exchange responds to changes in vapor pressure deficit (VPD) is key to predicting tropical forest resilience to climate change. Stomata regulate leaf water and CO2 diffusion, and respond to changes in temperature and relative humidity, two drivers of VPD. At high temperatures, the cuticular pathway may also become significant and participate in the overall leaf conductance. Here, we measured gas exchange under light and dark conditions to investigate the stomatal and cuticular responses to temperature and relative humidity on detached branches in five tropical tree species. Leaf conductance in the dark, when stomata are essentially closed, was not markedly impacted by temperature and relative humidity, suggesting a minimal response of the cuticular pathway to these conditions. We compared six steady-state conductance models incorporating different effects of photosynthesis and evaporative demand on stomatal control. All models performed well (RMSE <...

Distant Storms Can Affect Seismic Noise Crustal Monitoring

Tue, 16 Jun 2026 00:00:00 +0000

Abstract Using seismic noise interferometry to monitor the Earth's interior relies on continuous seismic wavefields produced by stable, invariant sources. In numerous applications, this condition is relaxed, arguing that secondary scattering effects render the late coda source independent. Using an 800‐km aperture seismic array in southwestern China, we identify strong teleseismic body waves (P, PP, PKPbc) embedded in the noise correlation functions in the secondary microseism frequency band (5–10 s) that exhibit seasonal variations correlating with changes in ocean wave heights at distant source regions. We demonstrate that these body wave arrivals generate cross‐talk artifacts that distort both ballistic and coda wavefields. Our findings challenge the assumption that late coda waves are source‐independent and highlight the need to account for body wave interference from distant storms to ensure reliable interpretations in ambient noise‐based studies. Plain Language Summary...

Multi‐Decadal Dynamics of Wetland Methane Emissions Revealed by Knowledge‐Guided Machine Learning

Thu, 11 Jun 2026 00:00:00 +0000

Measurement of methane fluxes (FCH₄) from natural systems, such as wetlands, has lagged far behind carbon dioxide fluxes. Short and fragmented wetland FCH₄ data limit our ability to assess its long-term dynamics and potential climate feedbacks. Extrapolating short-term FCH₄ records to recent decades remains challenging for both process-based models and data-driven machine learning (ML) approaches. Here, we develop a knowledge-guided ML framework that integrates eddy covariance (EC) FCH₄ observations, field warming experiments, and biogeochemical knowledge to reconstruct the long-term FCH₄ budgets and trends. Focusing on the 11 longest EC monitoring sites in the AmeriFlux network, we found considerable variability in multi-decadal trends of wetland FCH₄, with increases up to 14% per decade from 2000 to 2024. We also found that the strength of these increasing trends declines from high to low latitudes, highlighting...

PyHydroGeophysX: An extensible open-source platform for integrating hydrological models with geophysical measurements

Thu, 11 Jun 2026 00:00:00 +0000

Hydrological models and geophysical measurements are widely used tools for understanding subsurface hydrological processes relevant to water resource management, yet they typically remain disconnected due to technical barriers. We present PyHydroGeophysX, an open-source Python platform bridging this gap by providing standardized interfaces between hydrological modeling software (MODFLOW, ParFlow) and geophysical simulation tools (PyGIMLi, SimPEG). The platform implements bidirectional workflows: translating hydrological outputs into simulated geophysical responses through petrophysical models, and extracting hydrological information from geophysical inversions. Key features include bidirectional workflow modules, configurable petrophysical models, time-lapse inversion with temporal regularization, parallel computing, and mesh utilities for property transfer between geophysical and hydrological grids. The modular architecture of PyHydroGeophysX enables researchers to incorporate...

Forest aboveground biomass estimation through integration of sentinel-2 and PALSAR-2 time series: assessing models trained on GEDI and field inventory benchmarks

Wed, 10 Jun 2026 00:00:00 +0000

Accurate and spatially explicit forest Aboveground Biomass (AGB) mapping through remote sensing is critical for quantifying terrestrial carbon stocks and informing effective forest management strategies. However, AGB estimation in dense forests with complex terrain remains challenging due to satellite sensor signal saturation problem (saturation issue occurs in high biomass forests), structural complexity, and limited ground truth for calibration. This study presents a novel framework that integrates multi-temporal Sentinel-2 optical imagery, ALOS PALSAR-2 Synthetic Aperture Radar (SAR) data, and topographic variables with explainable Machine Learning to map AGB across mountainous forests within subtropical and temperate oceanic climate zones of Mexico. We evaluate the effects of temporal granularity and sensor synergy by comparing multiple temporal inputs and sensor configurations (Sentinel-2, PALSAR-2, and their fusion), and assess model performance using two reference datasets:...

Emergent constraints on future methane emissions from global wetlands

Wed, 10 Jun 2026 00:00:00 +0000

Future methane (CH4) emissions from natural wetlands are predicted to increase due to global warming, leading to positive feedback on climate change. However, the magnitude of this increase remains highly uncertain. Here we present novel ensemble simulations of seven state-of-the-art terrestrial biosphere models to estimate wetland CH4 emissions (eCH4) during the twenty-first century. Our estimates suggest that for every 1 °C increase in global land surface temperature, there is a 24 ± 10 Tg CH4 yr−1 increase in eCH4. We also identify an emergent relationship between contemporary temperature dependence and projected eCH4. When constrained by 163 site-year eddy-covariance measurements of eCH4, we show that wetland emissions can increase by 50–60% by the 2090s relative to the 2010s under a high-warming scenario. The projected decadal increase in eCH4 from the 2010–2019 baseline to the 2030s would very likely (90% probability) offset an amount equivalent in scale to 8–10% of anthropogenic...

A solid-state extrusion pathway extensible to upcycling aluminum scrap and end-of-life permanent magnets into ductile Al-6061/SmCo5 structural magnetic composites

Wed, 10 Jun 2026 00:00:00 +0000

Permanent magnets offer strong potential for multifunctional structural components, but their inherent brittleness limits direct integration. Here, SolidStir® Extrusion (SSE) is used to embed SmCo5 powder into AA6061 in the solid state, and the resulting microstructure, interfacial chemistry, mechanical properties, and magnetic response are systematically characterized. SSE fragments the initial SmCo5 powder into predominantly fine particles dispersed within an ultrafine Al matrix, with a volume fraction of ∼ 4–6 % in this proof-of-concept study. Interfacial reactions form a continuous Al–Co reaction layer, with local atomic-resolution indexing consistent with Al13Co4, together with Sm–Si-rich reaction products, while the matrix contains Sm–Co–Si-rich precipitates and Mg2Si, producing features from nanometers to micrometers. Compared with an Al extrudate, this architecture increases yield strength by ∼ 42 % and tensile strength by ∼ 31 %,...

Compound Mesoscale Convective Systems and Low‐Pressure Systems in Tropical Monsoon Regions: Assessing Their Meteorology and Precipitation

Wed, 10 Jun 2026 00:00:00 +0000

Abstract Mesoscale convective systems (MCS) and low‐pressure systems (LPS) are both strongly associated with precipitation across the regions where they occur, particularly within global monsoon systems; however, their co‐occurrence and its relationship to precipitation have not been systematically examined. Here, we use LPS and MCS trackers to detect compound MCS and LPS events in five monsoon regions and assess the association of this co‐occurrence with anomalies of winds, precipitation, and other atmospheric variables. Additionally, we investigate the spatial distribution of precipitating MCS and LPS events. Our results show that most (∼60%) MCS and LPS co‐occurrences are located in the lower latitudes, where they contribute up to 40% of annual precipitation. We find that compound events generally produce more extreme precipitation than MCS‐only or LPS‐only events. Furthermore, our assessment of the synoptic and mesoscale composites reveals that the underlying dynamics of compound...

Machine-learning-based estimates of global natural vegetated wetland methane emissions (2000–2025)

Wed, 10 Jun 2026 00:00:00 +0000

Abstract. Wetlands are the largest natural source of atmospheric methane (CH4), yet comprehensive global budgets are typically delayed by years, preventing a timely understanding of CH4 sources, sinks, and trends. To reduce this delay, we present a model emulator-driven framework and accompanying workflow that enable timely, continuous emission updates using a machine-learning emulator to reconstruct spatially explicit monthly emission fields at 1° × 1° resolution. We apply this framework to a global dataset of natural vegetated wetland CH4 emissions to extend the most recent Global Methane Budget (GMB; Saunois et al., 2025) record that covers the 2000–2020 emissions through 2025. In the test data (∼ 30 % of the total dataset), the emulator achieved a global R2 of 0.65 ± 0.003 (mean ± 95 % CI, hereafter) and an RMSE of 5.49±0.12×10-3 Tg CH4 yr−1. The emulator is trained on 35 GMB model estimates, including 22 process-based models and 13 atmospheric inversions, paired with 10 ensemble...

Leveraging Crowdsourced Data for Extreme Heat Monitoring

Wed, 3 Jun 2026 00:00:00 +0000

ABSTRACT The combined effects of urban microclimate heterogeneity and climate change exacerbate the disproportionate impact of heatwaves on urban areas, a trend expected to intensify. Crowdsourcing is a promising tool to monitor temperatures at a high spatiotemporal scale, which is now deemed critical. However, quality control is essential before the use of such data. Traditional quality control methods often fail to capture short extreme weather events like heatwaves, as they frequently eliminate crucial observations from these intense, brief episodes. Here, a quality control methodology, tailored to short‐term heatwaves built on existing quality control methods, is introduced and tested on crowdsourced monitoring networks for five North American cities and three heatwave episodes. This framework is centred around a systematic comparison with traditional weather stations. The results show that the designed procedure can effectively filter out false data points and corrupt stations...

Reactive transport modeling to support long-term monitoring strategy: Ion exchange induced contaminant remobilization at subsurface contaminated sites influenced by abrupt changes in geochemical conditions

Thu, 21 May 2026 00:00:00 +0000

This study presents a long-term monitoring strategy for early risk warning of the remobilization of contaminants, mainly attenuated through an ion exchange reaction, induced by abrupt changes in geochemical conditions. The strategy aims to utilize readily in-situ measurable groundwater quality parameters in the prediction of near-future contaminant remobilization caused by cation exchange reactions. The proposed approach was demonstrated using historical monitoring data from the Department of Energy (DOE) Savannah River Site (SRS) F Area, which experienced abrupt geochemical disturbance during the pump-treat-reinjection remedy, and a reactive transport model developed through this study to understand ⁹⁰Sr migration behavior in the subsurface of the SRS F Area. Both historical monitoring data analysis and reactive transport modeling results revealed a measurable temporal separation (time lag) between the arrival of background electrolyte perturbation and subsequent remobilized...

Plant litter chemistry and associated changes in microbial decomposition under drought

Thu, 21 May 2026 00:00:00 +0000

Drought has consequences for microbial decomposition rates, including indirect effects through changes in plant litter chemistry. Here, we studied the impact of a decade-long drought on plant litter chemistry and microbial decomposition traits in a semi-arid ecosystem during an 18-month litter bag experiment. We investigated litter sourced from four conditions: grass and shrub vegetation under ambient and reduced precipitation. We hypothesized that litter chemistry drives microbial decomposition capabilities and enzyme activity due to vegetation differences and drought effects on litter chemistry. We found that carbohydrate-rich grass litter had a higher abundance of decomposition genes detected using metagenomics and enzyme activity than more recalcitrant shrub litter, which was richer in lignin and lipids; these patterns were related to substrate supply. Drought decreased some carbohydrate fractions in grass litter but did not change the lignin fraction in grass and shrub litter,...

Identification of Rac guanine nucleotide exchange factors promoting Lgl1 phosphorylation in glioblastoma.

Thu, 21 May 2026 00:00:00 +0000

The protein Lgl1 is a key regulator of cell polarity. We previously showed that Lgl1 is inactivated by hyperphosphorylation in glioblastoma as a consequence of PTEN tumour suppressor loss and aberrant activation of the PI 3-kinase pathway; this contributes to glioblastoma pathogenesis both by promoting invasion and repressing glioblastoma cell differentiation. Lgl1 is phosphorylated by atypical protein kinase C that has been activated by binding to a complex of the scaffolding protein Par6 and active, GTP-bound Rac. The specific Rac guanine nucleotide exchange factors that generate active Rac to promote Lgl1 hyperphosphorylation in glioblastoma are unknown. We used CRISPR/Cas9 to knockout PREX1, a PI 3-kinase pathway-responsive Rac guanine nucleotide exchange factor, in patient-derived glioblastoma cells. Knockout cells had reduced Lgl1 phosphorylation, which was reversed by re-expressing PREX1. They also had reduced motility and an altered phenotype suggestive of partial neuronal...

Energy Emissions Accounting Methods Can Determine Whether Direct Air Capture with Storage Achieves Net Removal

Fri, 15 May 2026 00:00:00 +0000

The voluntary carbon market within the United States has expanded rapidly in recent years and enabled private companies and other organizations to provide revenue streams to carbon dioxide removal (CDR) technologies. For a CDR technology to participate in the voluntary carbon market (VCM), the emissions associated with constructing and operating the technology must be less than the CO₂ captured from the atmosphere. Assessing the extent to which this is true for direct air capture with storage (DACS), a relatively energy-intensive CDR technology, strongly depends on the accounting method used to assess the emissions intensity of purchased energy. We simulate the hourly weather-dependent operation of sorbent- and solvent-based DACS in California, Louisiana, Texas, and Wyoming, representing a wide range of local weather and electric and natural gas grid compositions. In all cases, the single most important emissions accounting decision is the method used to estimate the...

In situ quantification of fracture slip induced by hydraulic injections in a deep borehole: A comparison of two different borehole techniques

Wed, 13 May 2026 00:00:00 +0000

In situ measurements of fracture deformation during fluid injection are rare, yet essential for understanding the mechanical response of fractured rock. In this study, we evaluate the reliability of two methods by comparing their slip vector estimates: high-resolution borehole acoustic televiewer images captured before and after injection tests, and displacement data from a three-component borehole deformation probe recorded during the injections. Acoustic televiewer images capture only final in-plane displacement, whereas three-component borehole deformation measurements provide full 3D, transient fracture movement. Four injection tests in a fractured granitic rock mass along an inclined borehole at the Bedretto Underground Laboratory (Switzerland), beneath more than 1100 m of overburden, were analyzed. The two methods yielded consistent kinematics and comparable slip magnitudes, typically in the range of 0.2 – 0.6 mm. Angular differences between estimated slip directions...

Geomechanical properties of the Meletta sandstone - the high-temperature heat storage reservoir rock of DeepStor

Wed, 13 May 2026 00:00:00 +0000

The DeepStor project aims at storing excess heat at temperatures up to 140 °C in the depleted Leopoldshafen oil field at a depth of about 1300 m. In order to gain knowledge on the target horizons, the different layers of the Meletta sandstone, samples cored in a block retrieved in a quarry near Nussloch where the Meletta sandstone outcrops were studied. Several petrophysical properties were investigated including mineralogy, porosity, permeability, thermal conductivity, P- and S-wave velocities and quality factor. A mechanical study focused on compressive strength under uniaxial and triaxial stress conditions, tensile strength, critical pressure and stress-dependence of physical properties. Our results show that the Meletta sandstone is heterogeneous, anisotropic, mechanically weak, stress-sensitive and prone to water weakening. Petrophysical measurements on few Meletta sandstone cores retrieved in boreholes at about 1250 m depth showed that the outcrop samples are significantly...

Participatory modeling in the AI era

Tue, 5 May 2026 00:00:00 +0000

PM is a now established approach to improve the utility and actionability of modeling for decision making and management. With the advent of the AI era, there are multiple avenues for its use in the context of PM. We reviewed a number of recent papers that describe how various AI tools have been used to assist the PM process, both in improving the quality of modeling and the participation efficiency. We have identified AI applications that can help stakeholders in the process of knowledge acquisition and decision making during the steps of the PM process. We also looked at how AI has been put to several innovative uses in PM related areas, such as collective intelligence, deliberative democracy and participatory governance, and how these can be adopted and used in the PM process. These enhancements escalate in degree of AI intervention and autonomy. They start with augmenting approaches such as informing, modeling and data processing, and can lead to deeper AI engagement such...

Best practices in software development for robust and reproducible geoscientific models based on insights from the Global Carbon Budget's dynamic vegetation models

Fri, 24 Apr 2026 00:00:00 +0000

Abstract. Computational models play an increasingly vital role in scientific research by enabling the numerical simulation of complex processes. Such models are also fundamental in geosciences. For instance, they offer critical insights into the impacts of global change on the Earth system today and in the future. Beyond their value as research tools, models are also software products and should therefore adhere to certain established software engineering standards. However, scientists are rarely trained as software developers, which can lead to potential deficiencies in software quality like unreadable, inefficient, or erroneous code. The complexity of models, coupled with their integration into broader workflows, also often makes it challenging to reproduce results, evaluate processes, and build upon them. In this paper, we review the state and current practices of the development processes of the state-of-the-art land surface models used by the Global Carbon Budget. We combine...

Model‐Based Interpretation of Solute Exports and Carbon Partitioning During Shale Weathering in a Mountainous Hillslope

Fri, 24 Apr 2026 00:00:00 +0000

Abstract The weathering of sedimentary rocks in high‐elevation catchments influences freshwater quality and the global carbon cycle. While individual biogeochemical mechanisms involved in this process are relatively well understood, quantifying their contributions to solute export and carbon fluxes under natural, transient conditions remains challenging. Here, we implement a numerical multidimensional and multiphase model to simulate coupled hydrological and biogeochemical processes in a shale‐underlain, snow‐dominated hillslope in the Rocky Mountains, Colorado. The model captures the dynamic interplay between soil respiration, mineral weathering, and climate‐driven hydrological forcing, reproducing observed soil CO 2 dynamics, groundwater chemistry, and subsurface flow. Our results reveal that seasonal snowmelt enhances carbonate weathering by promoting the infiltration of CO 2 ‐rich water to depth, while pyrite oxidation is primarily sensitive to low water saturation that facilitates...

Sequential Fracture Activation and Stress Evolution During EGS Stimulation at Utah FORGE Revealed by Waveform Cross‐Correlation

Fri, 24 Apr 2026 00:00:00 +0000

Abstract Mapping fracture networks in Enhanced Geothermal Systems (EGS) is essential for optimizing reservoir performance, yet complex fracture evolution during stimulation remains difficult to resolve. This study examines the evolution of microseismicity and fracture networks during stage 3 of the 2022 EGS stimulation at the Utah Frontier Observatory for Research in Geothermal Energy site. We map the fracture network represented by 20 clusters of seismic events identified by waveform similarities with cross‐correlation. We characterize their geometric properties such as strike, dip, length, and width, and analyze the time evolution of activated fractures. The results reveal a systematic fracture evolution: early activation of pre‐existing natural fractures, complex network development during peak injection, and continued activation of less favorably oriented fractures post‐injection. Magnitude calibration using the Principal Component Analysis of cross‐correlated waveforms improves...

Organic colloid composition in variable-redox porewaters within a mountainous floodplain

Fri, 24 Apr 2026 00:00:00 +0000

Redox gradients, often driven by changes in sediment moisture levels in porous, heterogeneous groundwater systems, create dynamic conditions that may promote the production and transport of colloids within natural waters. While much research has focused on the inorganic composition of colloids, the organic composition remains less well understood. Organic matter (OM) in colloids may associate with minerals, complex metal ions, and serve as an electron donor for microbial respiration; therefore, its composition is of high interest. We examined the composition of porewater OM along a redox gradient in a riparian soil located along the Slate River in Crested Butte, Colorado, USA as a function of depth (90, 130, 200, and 350 cm below ground surface). All depths were oxic to suboxic, except 200 cm, where the products of iron and sulfate reduction were observed concomitant with an increase in dissolved and/or colloidal OM, pH, alkalinity, and conductivity. We investigated the composition...

Soil Moisture Buffers the Impact of Precipitation Variability on Ecosystem Productivity

Thu, 23 Apr 2026 00:00:00 +0000

Abstract Water availability governs ecosystem productivity, yet estimates of vegetation sensitivity to water can differ greatly depending on whether the sensitivity is examined spatially or temporally. In particular, the spatial sensitivity is often reported to be much stronger than temporal sensitivities, leading to highly uncertain projections of ecosystem responses to future climate change when using space‐for‐time substitution. The large difference between spatial and temporal sensitivities remains unexplained. Prior research, however, primarily relied on precipitation as the water availability proxy, whereas vegetation responds to soil moisture. Here, we combined satellite estimates of vegetation productivity with soil moisture data across water‐limited ecosystems of the continental United States (CONUS) to identify a convergent sensitivity of productivity to water availability. Using precipitation, we show that temporal sensitivity is 66% lower than spatial sensitivity overall....

Bioenergy Cropping Reduces the Spatiotemporal Scaling of Soil Bacterial Biodiversity

Thu, 23 Apr 2026 00:00:00 +0000

Widespread bioenergy cropping can transform landscapes, strongly affecting biodiversity. However, the impact of bioenergy cropping on the spatiotemporal scaling of soil biodiversity remains virtually unknown, despite its profound implications for the functioning of the ecological community. Here, we investigated how bioenergy cropping influenced the spatiotemporal scaling of soil bacterial biodiversity in marginal soils (sandy loam and clay loam soils) in Oklahoma, USA. We detected strong, significant species-time-area relationships (STARs) and phylogenetic-time-area relationships (PTARs) in bacterial communities and their lineages, suggesting that STARs and PTARs exist in microbial ecology within the studied system. Also, spatiotemporal scaling rates (the slopes of STAR and PTAR models) varied substantially among bacterial lineages and were positively correlated with their 16S rRNA gene copy numbers, a genomic trait indicative of microbial growth potentials. Strikingly, bioenergy...

A global methane observation system to track climate feedbacks for verifiable climate impact

Wed, 22 Apr 2026 00:00:00 +0000

Methane measurements, particularly of natural sources, need to be expanded considerably.

Production of Agricultural Water and Nutrients from Brackish Water Sources

Tue, 21 Apr 2026 00:00:00 +0000

Arid agricultural regions worldwide face critical challenges of water scarcity and soil salinization, significantly reducing crop production. This study investigates a circular economy and systems approach to desalination with nutrient recovery (DNR), economically producing irrigation-quality water while recovering valuable nutrients from brackish waters. A preliminary design tool for sizing the calcium (Ca) and magnesium (Mg) hardness ion removal component was developed through laboratory testing of the cation exchange (CIX) process. Key findings include (1) KCl and NaCl salts effectively regenerated the CIX resin, reducing and facilitating recovery of scale-causing Ca and Mg ions by greater than 99.5% to approximately 1 mg/L as CaCO3. KCl benefits agriculture and the environment relative to traditional NaCl regenerant as K can be recovered, along with the Ca and Mg, and used locally as plant nutrients, reducing fertilizer production/importation and waste generation. (2) The...

Inference of pile capacity from distributed strain sensing via PDE-constrained optimization

Thu, 16 Apr 2026 00:00:00 +0000

Distributed fiber-optic sensing (DFOS) provides high-resolution, continuous strain measurements along piles, offering new opportunities for detailed assessment of pile quality and soil–structure interaction. However, field DFOS data often exhibit oscillatory patterns traditionally treated as noise, obscuring actual physical insights into variations in pile radius and shaft friction for example. To address this challenge, we propose a numerical framework that formulates the strain-matching problem as a partial differential equation constrained optimization (PDECO) problem. This approach not only infers pile quality and soil response profiles from noisy DFOS data, but also rigorously enforces mechanical equilibrium at each loading step, yielding a physically consistent interpretation of high-resolution distributed measurements. Numerical benchmarks and application to a DFOS-monitored pile load test demonstrate that the PDECO scheme is robust to measurement noise and capable of reconstructing...

Contrasting Parametric Sensitivities in Two Global Vegetation Models Using Parameter Perturbation Ensembles

Wed, 15 Apr 2026 00:00:00 +0000

Abstract Uncertainty in land model projections remains high and the roles of parametric and structural uncertainty are difficult to disentangle. To compare parametric sensitivity across model structures we present two parameter perturbation ensembles using the Community Land Model (CLM) operating in satellite phenology mode. The ensembles contrast two vegetation modules: (a) the default CLM vegetation module and (b) the Functionally Assembled Terrestrial Ecosystem Simulator (CLM‐FATES). We perturbed over 300 parameters and quantified their effects on biophysical fluxes globally and across biomes. Most parameters have minimal impact on biophysical fluxes, with only a few substantially influencing results. While both models exhibit similar parameter sensitivity for some fluxes, CLM‐FATES shows larger spread in gross primary productivity (GPP), driven by strong sensitivity to carboxylation rate. CLM‐FATES also shows a weaker GPP response to soil hydrology parameters and exhibits...

A Boundary Element Model for Assessing Large‐Scale Pressurization in Faulted Geological Storage Systems

Tue, 14 Apr 2026 00:00:00 +0000

Abstract Assessing large‐scale pressurization at the regional scale—a possible outcome of large subsurface storage applications such as wastewater injection and geological carbon sequestration—presents significant computational challenges. These challenges are particularly pronounced when accounting for complex geologic structures with multiple reservoir and caprock layers, fault zones, and wells. This study introduces a computationally efficient model that integrates single‐phase semi‐analytical solutions with a boundary element (BE) approach. The model simulates pressure propagation in multilayered 3D systems, including vertical faults, caprock, basement, and confining units. We apply this new model to a representative scenario involving CO 2 injection near a partially sealing fault with verification against an independent two‐phase flow model. Results demonstrate that our model accurately captures far‐field pressure responses and that, outside the CO 2 plume zone, pressure...

Recent Increasing Trend in October–November Caribbean Tropical Cyclone Activity

Tue, 14 Apr 2026 00:00:00 +0000

Abstract October–November Caribbean tropical cyclone (TC) activity has significant impacts for both the Caribbean islands and Central America (e.g., Hurricanes Eta and Iota in 2020). October–November Caribbean TCs can also track northward and make continental United States landfall, resulting in substantial damage and fatalities (e.g., Hurricane Michael in 2018 and Delta and Zeta in 2020). We find significant increasing trends in October–November Caribbean hurricanes, rapidly intensifying hurricanes (winds increasing by ≥15 m s −1 within 24 hr), and landfalling hurricanes during the global satellite era (1979–present). Since 1979, we also observe significant warming trends in the western Atlantic Warm Pool and anomalous relative cooling in the eastern Pacific during October–November. These trends yield a more conducive dynamic and thermodynamic environment for Caribbean TCs, including reductions in Caribbean vertical wind shear, increases in Caribbean...

Insights into the hydro-mechanical behavior of a decimeter-scale fracture using the mini-SIMFIP probe

Mon, 13 Apr 2026 00:00:00 +0000

ABSTRACT: Understanding hydro-mechanical couplings in fractured rocks is essential for predicting the rock mass response during high-pressure fluid injection, including the stimulation of enhanced geothermal systems. However, fluid-driven fracture dislocations are challenging to measure due to the need for local displacement data at high fluid pressures. In this study, fluid-driven displacement across a decimeter-scale laboratory fracture was investigated using the mini-SIMFIP (step rate injection method for fracture in-situ properties) probe, which is a smaller version of the SIMFIP tool (Guglielmi et al., 2014). The mini-SIMFIP probe is able to resolve the full 3D displacement vector of a fracture. The probe was installed in one of two boreholes across a decimeter-scale saw-cut granite fracture. Two pressure step injection tests were conducted under the same isotropic stress conditions. By varying injection between the boreholes, we estimated the aperture profile across the...

Why Firn Quakes

Fri, 10 Apr 2026 00:00:00 +0000

Abstract Snow dampens sounds, but anecdotal reports concisely describe audible propagating collapse events—firnquakes—in Antarctic and Arctic snowfields. We propose combining granular and continuum mechanics to form a testable theory for conditioning, triggering, and propagation of firnquakes consistent with scarce data. A central condition for collapse events is unconsolidated firn at depth. As firn grains compact, stresses are transmitted along force chains which carry the overburden and transition into a continuous medium by pressure sintering. This granular legacy creates solid‐like supports of denser layers that keep the material below unconsolidated. Dynamic amplification triggers local brittle failure of the supports, which induces a cascade of collapse propagation. Using bulk density from ice cores as proxy for stiffness, we find the flexural wave speed by collapsing supports matches the recorded firnquake velocities on the order of 100 m/s. Our theory is to be tested...

International Collaboration Activities in Geologic Disposal R&D: FY25 Progress Report Spent Fuel and High-Level Waste Disposition

Thu, 2 Apr 2026 00:00:00 +0000

International Collaboration Activities in Geologic Disposal R&D: FY25 Progress Report Spent Fuel and High-Level Waste Disposition

Storylines for the 1997 New Year’s Flood: The role of watershed antecedent conditions and future warming in shaping discharge in the Truckee River watershed

Thu, 2 Apr 2026 00:00:00 +0000

The 1997 New Year’s flood was among the most devastating floods in the Truckee River watershed located in western Nevada. This event resulted from complex interactions of flood drivers, such as extreme precipitation, wet antecedent watershed conditions, warm temperatures and rapid snowmelt. We leveraged simulated forcings from the regionally refined mesh capabilities of the Energy Exascale Earth System Model (RRM-E3SM) and a process-based hydrological model to recreate the 1997 New Year’s flood for the Truckee River watershed across four climate warming levels ranging from the current temperatures to + 4° C. For each scenario, we conducted ensemble simulations with the same forcing but with 100 different seasonal watershed antecedent conditions, which were randomly sampled from long-term hydrological simulations. The results show that the 1997 New Year’s flood can be reproduced or exceeded consistently only when the antecedent watershed conditions are wet, specifically...

Coupling geophysical, geological, geochemical and mineralogical assessments to examine preferential contaminant transport pathways in interbedded fractured bedrock

Thu, 2 Apr 2026 00:00:00 +0000

This study shows that a multi-faceted approach, combining borehole geophysical logging and surface seismic P-wave first-arrival tomography with confirmatory coring, well installation, and chemical and mineralogical analysis, is effective for identifying difficult-to-locate preferential contaminant transport pathways in deeper fractured bedrock. Seismic tomography detected porous 10-20 m wide elongated fractured conduits that allow acidic groundwater contaminated with uranium (U) and nitrate (NO₃^-) to migrate within interbedded shale-limestone bedrock over 1000 m from a former disposal facility (S-3 Ponds site) located at the DOE Y-12 National Security Complex in Tennessee (USA). Conventional drilling techniques would easily miss these conduits because they are oriented parallel with fractured bedding planes. Synchrotron analysis of aquifer solids revealed that > 95 % of the U is hexavalent (U^VI). This uranyl (UO₂²⁺) species...

Microstructure of amide-functionalized polyethylenes determined by NMR relaxometry

Tue, 31 Mar 2026 00:00:00 +0000

Amidation of polyethylenes creates a range of amide-containing materials with enhanced properties, but the effect of these functional groups on the microstructure of these new materials is not known. Here we employ solid-state nuclear magnetic resonance (NMR) techniques to analyze the microstructure of amide-modified polyethylenes. While a decrease in crystallinity was observed with increasing amounts of functionalization, we found by measuring the chain mobility of the crystalline, amorphous, and interphasial regions of the polyethylenes with NMR relaxation techniques that the grafted amidyl groups partition into the rigid amorphous fraction (RAF) between the crystalline and amorphous regions. The chemical specificity of these NMR experiments creates precise assessments of the location of functional groups within the materials. Together, these insights into the microstructure and morphology of amide-containing polyethylenes lay a foundation for a deeper understanding of the structure...

Thermo-hydro-mechanical analysis of subsurface ice-based thermal energy storage

Mon, 30 Mar 2026 00:00:00 +0000

Ice-based thermal energy storage systems are widely utilized for cooling and managing peak electrical demand globally, offering daily or weekly storage capabilities for both individual homes and larger office buildings. However, scaling these systems for district-level cooling or integrating them with renewable energy sources presents challenges, especially in accommodating larger volumes and addressing seasonal storage requirements in densely populated urban areas. This paper proposes a novel solution by evaluating subsurface ice-based thermal energy storage, in which the underground is subjected to seasonal freeze/thaw cycles. However, these cycles may influence ground behavior, affecting pore pressure and inducing ground movement. To systematically investigate these challenges, we enhance the TOUGH-FLAC simulator by integrating water/ice phase change capabilities and updating the effective stress–strain constitutive relation. Both modifications are validated against analytical...

Depth of nutrient uptake by deep-rooted plants is regulated by water availability

Mon, 30 Mar 2026 00:00:00 +0000

The capacity of some plants to access water and nutrients at depths greater than one meter is a critical functional trait that confers resistance to drought and impacts both belowground and shallow soil processes. Here, we report water and strontium isotopic data from an alpine meadow transect showing the correlation between water and nutrient acquisition depths. The isotopic compositions of Sr (⁸⁷Sr/⁸⁶Sr ratio) and water in rock and soil, and in plant leaf tissues, reveal that deeper-rooted plants acquire a higher proportion of water, Sr, and cation nutrients that are derived from the saprolite, a zone of silicate weathering, than shallow-rooted grass. A three-decade dendrochemical record reveals that reductions of wet precipitation drive deep-rooted plants to acquire cation nutrients from deeper saprolite or bedrock regions. Thus, the depth of cation nutrient acquisition by deep-rooted plant species at this site is tightly coupled with, and likely determined...

Dataset about Warming Effects on Carbon Cycling and Greenhouse Gas Fluxes in Permafrost Ecosystems

Fri, 27 Mar 2026 00:00:00 +0000

Field observations provide direct evidence of how does carbon cycling in permafrost ecosystems respond to climate change. This study provides a comprehensive dataset on the impact of warming on carbon cycling and greenhouse gas (GHG) fluxes in permafrost ecosystems. The dataset is extracted and integrated from 132 peer-reviewed studies with 1430 paired observations across eight major permafrost ecosystems, including Arctic and subarctic tundra and wetland, and alpine meadow, steppe, tundra and wetland. This dataset includes 17 variables from experiments conducted during the growing season, covering the plant and soil carbon pools, soil nitrogen pool, and GHG (i.e., CO2, CH4, and N2O) fluxes, among others. Background information on site climate conditions, vegetation and soil characteristics, and details of the warming experiments, including timing, methods, and warming magnitude, are also contained in the dataset. This dataset facilitates a comprehensive understanding of the impact...

Real-Time GPU-Accelerated OFDR With an Integrated Auxiliary Interferometer

Wed, 25 Mar 2026 00:00:00 +0000

A GPU-accelerated optical frequency domain reflectometry (OFDR) system with an improved integrated auxiliary interferometer is proposed. Unlike conventional approaches that require separate auxiliary interferometers and multiple detection channels, the proposed OFDR system embeds this functionality directly into the signal via an intentional beat component. This enables self-calibration of laser nonlinearity while maintaining a cost-effective hardware configuration. Building on this simplified configuration, the system leverages GPU acceleration with an NVIDIA RTX 4070 Ti to achieve real-time performance, delivering high-throughput signal processing for continuous OFDR interrogation. The signal processing pipeline comprises signal capture, resampling for nonlinearity compensation, and frequency shift computation, all optimized for parallel execution. Hardware benchmarking demonstrates substantial acceleration over CPU implementations, achieving up to a $45\times $ speedup for...

Real-time well integrity monitoring in underground gas storage wells using distributed temperature and strain sensing: a field demonstration

Fri, 20 Mar 2026 00:00:00 +0000

This article presents the first successful field demonstration of a combined distributed temperature and strain sensing (DTSS) system installed directly on newly replaced tubing in a 5400-ft-deep operational underground gas storage well. The DTSS system uses a single optical fiber to monitor temperature and strain in real-time, providing a cost-effective solution for long-term well integrity assessment. In this study, the strain–stress correlation of the tubing—representative of material behavior analysis—is investigated as a potential method for monitoring tubing integrity throughout its lifetime. Moreover, the DTSS system’s capability to support both continuous and discrete monitoring is evaluated by comparing future data with historical records, enabling the early detection of issues such as material fatigue, corrosion, or deformation. Overall, the work examines the effectiveness and scalability of the DTSS system for real-time monitoring of well operations and integrity in...

A tale of two towers: comparing NEON and AmeriFlux data streams at Bartlett Experimental Forest

Thu, 19 Mar 2026 00:00:00 +0000

Long-term ecological data are essential for detecting impacts of climate change and other global change factors, and for making informed predictions about future change. However, long-term measurements are rarely replicated at the site level, which raises questions about their representativeness. We used a multiscale approach to evaluate the agreement of parallel observations from AmeriFlux and NEON (National Ecological Observatory Network) towers at Bartlett Experimental Forest, New Hampshire, USA. The two towers are separated by a horizontal distance of 93 m. We focused our analysis on standard meteorological variables; fluxes of CO2, sensible heat, and latent heat measured by eddy covariance; and phenology derived from PhenoCam imagery. Results suggest excellent agreement between AmeriFlux and NEON in meteorology and phenology, and good agreement in fluxes at the half-hourly scale. However, large disagreements in CO2 and latent heat fluxes occurred at the annual scale, with...

Coupled Thermo-Hydrological-Mechanical-Chemical Behavior of Anisotropic Granite for Geologic Disposal of High-Level Radioactive Waste: A Core-Scale Laboratory Investigation

Thu, 19 Mar 2026 00:00:00 +0000

The coupled thermo-hydrological-mechanical-chemical (THMC) behavior of rock within an Excavation Damaged Zone (EDZ) is critical for the safety and long-term performance of a geological repository for high-level radioactive wastes. While many laboratory experiments have been conducted to investigate EDZ rocks, the flow and deformation characteristics resulting from anisotropic rock textures and microcrack distribution under triaxial loading and elevated temperatures remain poorly understood. Particularly, cracks at various scales serve as fast paths for fluid flow and solute transport and present as focal points of mechanical weakness, which complicate the coupled THMC processes in anisotropic EDZ rocks and challenge modeling predictions. In this study, a series of core-scale experiments was conducted on three granite samples under repository-relevant conditions. These rock samples were obtained from the Grimsel Underground Research Laboratory (URL), featured by anisotropic minerals...

3D Deep Learning Joint Inversion of Active Seismic Full Waveform and Passive Seismic Traveltime Data for Reservoir Imaging and Uncertainty Quantification

Thu, 19 Mar 2026 00:00:00 +0000

ABSTRACT We present deep learning (DL) networks for three‐dimensional (3D) joint inversion of active seismic full waveform and passive seismic traveltime data to image reservoirs and their properties and quantify imaging uncertainties. Active seismic full‐waveform data can provide high‐resolution monitoring images but are collected only intermittently because of their high acquisition cost. In contrast, passive seismic data can be gathered at relatively low cost between regular active surveys, although their imaging quality can be compromised by factors such as low signal‐to‐noise ratios and limited ray coverage of the target. Although these datasets are routinely acquired together at CO 2 storage sites, their combined inversion within a 3D DL framework has not been previously demonstrated. To our knowledge, this is the first study to address this gap, combining the strength of both data types. For efficient data storage and DL training with large 3D seismic datasets, we use...

A Method for Rapid and Precise Triple Oxygen Isotope Measurements via High-Temperature Conversion to CO Followed by Nickel-Catalyzed CO to CO2 Conversion and Laser Spectroscopy

Fri, 13 Mar 2026 00:00:00 +0000

Triple oxygen isotopic compositions (¹⁶O, ¹⁷O, ¹⁸O) have conventionally been measured via isotope ratio mass spectrometry using O₂ as an analyte. Conversion of sample oxygen to O₂ typically utilizes fluorination chemistry or catalytic equilibration between CO₂ and O₂. Recently, laser spectroscopy has become a viable alternative for triple oxygen isotope (Δ'¹⁷O) measurements due to its ease and rapid throughput. Laser spectrometers are currently available for Δ'¹⁷O analysis of either H₂O or CO₂ as the analyte gas. So far, these instruments have been used to measure Δ'¹⁷O of water, carbonate (CO₂ liberated by acid digestion), and atmospheric CO₂ samples. We present a new method for high-precision Δ'¹⁷O analysis of CO₂ via tunable infrared laser direct absorption spectroscopy that is compatible with a wider...

Thermal stress in degraded forests in the Brazilian Amazon Arc of Deforestation

Fri, 13 Mar 2026 00:00:00 +0000

Understanding thermal stress in tropical forests has taken on new urgency in light of accelerating climate change and expansion of deforestation and forest degradation. Degraded tropical forests in particular may be approaching critical temperature thresholds even more rapidly than intact forests, with implications for tree survival and ecosystem recovery. We investigate thermal stress in degraded tropical forests within the Brazilian Amazon Arc of Deforestation. Using land surface temperature data from the ECOsystem Spaceborne Thermal Radiometer Experiment on the international Space Station (ECOSTRESS), we compared canopy temperatures of intact, selectively logged, and burned forests in Feliz Natal, Mato Grosso, Brazil. Upper canopy temperatures in previously burned forests were 4.1% higher (mean = 36.5 °C) and 50.9% more variable compared to intact and logged forests, which showed remarkably similar temperature distributions (means of 34.9 °C and 35.1 °C, respectively). Modeled...

Determining the extent of potential fugitive fluid migration from geologic carbon storage in hydrocarbon-bearing reservoirs: Insights from one-dimensional numerical modeling

Wed, 11 Mar 2026 00:00:00 +0000

Numerical modeling of Geologic Carbon Sequestration in permeable reservoirs initially containing hydrocarbons is conducted using the multi-phase, multi-component thermohydrologic simulator TOGA (TOUGH Oil, Gas, Aqueous; TOUGH stands for Transport Of Unsaturated Groundwater and Heat), to determine how phase and composition of the original fluids influence the extent of the zone where upward fugitive fluid migration could potentially occur, denoted Rf . The area within Rf comprises regions of substantially elevated pressure and free-phase CO2 saturation, where a breach in reservoir sealing capacity would lead to upward fugitive fluid migration. The model examines the conditions within the storage reservoir that could lead to fugitive flow, but does not model the fugitive flow itself. A one-dimensional radial model of the storage reservoir is used, and three initial phase conditions are considered: single-phase aqueous, two-phase gas-aqueous, and three-phase oil-gas-aqueous. Components...

Topography and functional traits shape the distribution of key shrub plant functional types in low-Arctic tundra

Wed, 11 Mar 2026 00:00:00 +0000

The expansion of shrubs in the Arctic tundra fundamentally modifies land-atmosphere interactions. However, it remains unclear how shrub distribution and expansion differ across key species due to challenges with discriminating tundra plant species at regional scales. Here, we combined multi-scale, multi-platform remote sensing and in situ trait measurements to elucidate the distribution patterns and primary controls of two representative deciduous-tall-shrub (DTS) genera, Alnus and Salix, in low-Arctic tundra. We show that topographic features were a key control on DTSs, creating heterogeneous, but predictable distributions of Alnus and Salix fractional cover (fCover). Alnus was more tolerant of elevation and slope and was found on hilly uplands (slope >10°) within a specific elevational band (200-400 m above sea level [MSL]). In contrast, Salix occurred at lower elevations (50-300 m MSL) on gentler slopes (3-10°) and required...

Autonomous elemental characterization enabled by a low cost robotic platform built upon a generalized software architecture

Wed, 11 Mar 2026 00:00:00 +0000

A generalized software architecture based on dual-layer action servers facilitates the development of autonomous experimental systems. An autonomous elemental characterization platform serves as an example of such a system. Despite the rapidly growing applications of robots in industry, the use of robots to automate tasks in scientific laboratories is less prolific due to the lack of generalized methodologies and the high cost of hardware. This paper focuses on the automation of characterization tasks necessary for reducing cost while maintaining generalization and proposes a software architecture for building robotic systems in scientific laboratory environments. A dual-layer (Socket.IO and ROS) action server design is the basic building block, which facilitates the implementation of a web-based front end for user-friendly operation and the use of ROS Behavior Trees for convenient task planning and execution. A robotic platform for automating mineral and material sample characterization...

Tradeoffs between uniform land protection and biodiversity-specific land protection with <2 °C global warming

Tue, 10 Mar 2026 00:00:00 +0000

Nearly 200 countries have pledged to conserve 30% of terrestrial ecosystems to stop the global biodiversity crisis. However, biodiversity is not uniformly distributed across countries. Adequately addressing this crisis requires a scientific basis for selecting protected land that considers both ecological benefits and impacts to humans. We use the global change analysis model to evaluate land use tradeoffs of four land protection cases under two climate cases. We find that biodiversity-specific land protection up to 39% globally can reduce land use constraints and food prices compared to protecting 30% of land uniformly in each country (’30 × 30’ initiative). Valuing terrestrial carbon for climate change mitigation reduces land conversion pressure and can complement protection strategies. Global impacts to agriculture of additional land protection are small, but regional impacts vary and may be considerable. Overall, biodiversity-specific land protection has greater potential...

Radiative, Hydrologic, and Circulation Responses to Warming in Cess‐Potter Simulations Using the Global 3.25‐km SCREAM

Tue, 10 Mar 2026 00:00:00 +0000

Abstract Using the global 3.25‐km Simple Cloud Resolving E3SM Atmosphere Model (SCREAM 3 km), a pair of 13‐month Cess‐Potter simulations are performed to quantify the radiative feedbacks and the hydrologic and circulation responses to warming. Large‐scale aspects of SCREAM 3 km's top‐of‐atmosphere radiative fluxes, precipitation rates, and circulations are in good agreement with observations and reanalysis, with notable differences, including a drier lower free‐troposphere in the Tropics, reduced precipitation and humidity over the Tropical West Pacific, and poleward shifted Southern Hemisphere midlatitude jet. In response to warming, SCREAM 3 km predicts a total radiative feedback within the top 15% of the CMIP5 and CMIP6 models, which puts it substantially higher than the feedback reported by other kilometer‐scale models. SCREAM 3 km's high radiative feedback stems from a strongly positive shortwave cloud feedback, most prominent over the mid‐ and high‐latitudes....

Simulating Hurricane Katrina in the Simple Cloud‐Resolving E3SM Atmosphere Model v1

Fri, 6 Mar 2026 00:00:00 +0000

Abstract Climate models are important tools for advancing understanding and prediction of tropical cyclones (TCs). Traditional global climate models, however, do not have the ability to properly simulate TC intensity due to their coarse horizontal resolution. Regional models can be run at convection‐permitting resolutions, but these models are often strongly influenced by the data used in the lateral boundary forcing, and domain choice can have a large impact on the simulation. Cloud‐resolving global climate models have demonstrated great potential for realism in TC simulations, and in this study we focus specifically on the Simple Cloud‐Resolving Energy Exascale Earth System Model (E3SM) Atmosphere Model (SCREAM) v1 configuration. We evaluate SCREAMv1 against the observational record and the Weather Research and Forecasting (WRF) model run at a convection‐permitting resolution with Hurricane Katrina as our case study. We found that both models produced realistic simulations of...

Strain release through hydrogen bond–mediated layer twisting

Wed, 4 Mar 2026 00:00:00 +0000

Strain engineering, enabling the precise control over structure and functional properties, is a key strategy for the design of advanced materials. However, the mechanisms governing strain evolution and release at the nanoscale remain largely unexplored. In this study, we leverage in situ heating transmission electron microscopy and synchrotron x-ray spectroscopy to investigate the strain relaxation pathways of boehmite (γ-AlOOH) at 575 kelvin by revealing real-time structural dynamics. Through tracking the moiré pattern evolution, we identify distinct strain release mechanisms, including layer twisting, defect formation, and domain restructuring. Our neural network potential calculations reveal that energy fluctuations at small twist angles are dominated by an interference-like interaction modulation of hydrogen bonds between boehmite interlayers, with metastable twisted structures corresponding to local minima of the potential energy landscape. This work establishes a previously...

Coupled geomechanical investigation of depletion-induced fault reactivation

Tue, 3 Mar 2026 00:00:00 +0000

Fault reactivation during subsurface fluid production pose significant challenges to safe and sustainable resource extraction. This study presents a three-dimensional coupled geomechanical framework to investigate the processes driving fault reactivation, capturing the interactions between reservoir dynamics and geomechanical responses. Verification against theoretical estimations based on linear poroelasticity confirms the model's capacity in representing reservoir background stress responses. However, the study reveals that relying solely on background stress states can underestimate or overestimate fault reactivation potential, emphasizing the importance of including localized stress perturbations such as differential compaction and stress redistribution. Applied to a fault (M1) inspired by the geological characteristics of the Groningen field, the model shows slip initiation at 2965 m depth with 16.0 MPa depletion, aligning with field observations where seismicity...

Duration of super-emitting oil and gas methane sources

Thu, 26 Feb 2026 00:00:00 +0000

The duration of super-emitting events (>100 kg h-1) in oil and gas basins remains insufficiently understood but is key for reporting programs and mitigation strategies. Carbon Mapper conducted aerial surveys from April 30 to May 17, 2024, over the New Mexico Permian Basin, covering 276,000 wells, 1100 compressor stations, 175 gas processing plants, and 27,000 km of pipeline. We find over 500 super-emitting sources with 300 of these sources observed repeatedly across multiple days. We quantify total super emissions by integrating individual events with observationally constrained event durations (5.98 −14.7 Gg CH4) and compare to total emissions derived from basin average snapshots (12.7 ± 0.92 Gg CH4). This gap between emission estimates is reconciled through assumptions on missed detections, characteristic event duration, detection frequency, and diurnal variability. Emission events generally lasted for at least 2 hours, and a small subset of sources (18 total), persistently...

Modeling glass degradation and release of radionuclides from vitrified waste for performance assessment simulations

Thu, 26 Feb 2026 00:00:00 +0000

The release of radionuclides initially encapsulated in a slowly degrading solid waste form and contained in an eventually corroding canister defines the source term for numerical simulations for the assessment of a geologic repository for high-level radioactive waste. While the details of waste degradation, canister corrosion, and dissolution and mobilization of the radionuclides in pore water include complex chemical reaction and transport processes that are coupled to the thermal, hydrological, microbiological, and mechanical conditions in the repository, the source-term model suitable for use in a numerical performance assessment model should be a defensible abstraction of these mechanisms. We developed a radiological source-term model and implemented it into a non-isothermal flow and transport simulator. While the proposed source-term model is applicable to various waste forms, canister systems, and disposal concepts, we specifically considered radionuclide releases from vitrified...

Quantifying Earth's Topography: Steeper and Larger Than Projected in Digital Terrain Models

Tue, 24 Feb 2026 00:00:00 +0000

Abstract Grid‐ or pixel‐based models, used across various scientific disciplines from microscopic to planetary scales, contain an unquantified error that bias our interpretation of the data. The error is produced by projecting 3D data onto a 2D grid. For Digital Terrain Models (DTMs) the projection error affects all slope‐dependent topographic metrics, like surface area or slope angle. Due to the proportionality of the error to the cosine of the slope, we can correct for it. We quantify the error and test the correction using synthetic landscapes for which we have analytical solutions of their metrics. Application to real‐world landscapes in California, reveal the systematic underestimation of surface area by up to a third, and mean slope angles by up to 10° in steep topography in current DTMs. Correcting projection errors allow for true estimates of surface areas and slope distributions enabling physics‐based models of surface processes at any spatial scale. Plain Language Summary...

Long-term soil warming decreases fungal biomass and alters fungal but not bacterial communities in a temperate forest

Tue, 24 Feb 2026 00:00:00 +0000

Long-term soil warming may alter microbial community structure and functioning in forest soils, thereby affecting carbon and nutrient cycling processes. We examined the effects of >14 years of soil warming (+4°C during snow-free seasons) on the fungal biomass marker ergosterol, and on fungal and bacterial communities in a spruce dominated mountain forest in the Austrian Alps. Soil warming decreased ergosterol, and the ergosterol-to-microbial biomass carbon (MBC) ratio at 0-10 and 10-20 cm soil depth, with a stronger decline in ergosterol, indicating a higher sensitivity of fungi than bacteria to long-term warming. Warming also shifted the fungal community at both soil depths, favoring Boletus luridus, an ectomycorrhizal (ECM) fungus, which emerged as the dominant OTU in warmed plots. The dominance of ECM over saprotrophic fungi (SAP) under warming at topsoil likely resulted from increased fine root production and enhanced competition for substrates and nutrients. Bacterial...

Water availability modulates maximum canopy heights of low-elevation Amazonian second-growth forests

Tue, 17 Feb 2026 00:00:00 +0000

Tropical second-growth forests of the Amazon sequester large amounts of carbon and are important carbon sinks, contributing substantially to climate change mitigation, biodiversity conservation, and providing crucial ecosystem services. Deforestation due to selective logging and shifting cultivation is expanding second-growth forest areas in tropical forest regions, which if well managed, regenerate rapidly over time. Maximum forest canopy height is an important metric of biomass and carbon accumulation in second-growth forests and is strongly influenced by water availability. The water limitation hypothesis explains the positive influence of water availability on maximum tree heights and has been examined and demonstrated at a small-scale using field data, and at a global scale, with limited accuracy, using remote sensing data in tropical ecosystems. However, this hypothesis concerning maximum canopy height has not been much studied at regional and national scales for tropical...

The Influence of African Easterly Waves on Atlantic Tropical Cyclone Tracks and Landfall in Large Ensembles

Wed, 11 Feb 2026 00:00:00 +0000

Abstract African easterly waves (AEWs) are an important precursor or “seed” for Atlantic tropical cyclones (TCs), with 60%–80% of major hurricanes observed to originate from AEWs. However, climate model simulations indicate that AEWs are not necessary to maintain annual Atlantic TC frequency. Furthermore, small ensembles suggest that AEWs may impact the spatial distribution and landfall of Atlantic TCs. Here, we investigated the influence of AEWs on the spatial distribution of Atlantic TC tracks and landfall using 50‐member ensembles of TC‐permitting regional model simulations for five hurricane seasons characterized by different levels of TC activity. The control simulations are seasonal hindcasts in which AEWs were prescribed through the eastern lateral boundary condition using reanalysis. In the experiments, we suppressed AEWs by applying a 2–10 day filter to the eastern lateral boundary condition. In response to AEW suppression, we discovered statistically significant...

PhaseT3M: 3D imaging at 1.6 Å resolution via electron cryo-tomography with nonlinear phase retrieval

Wed, 11 Feb 2026 00:00:00 +0000

Electron cryo-tomography (cryo-ET) enables 3D imaging of complex, radiation-sensitive structures with molecular detail. However, image contrast from the interference of scattered electrons is nonlinear with atomic density and multiple scattering further complicates interpretation. These effects degrade resolution, particularly in conventional reconstruction algorithms, which assume linearity. Particle averaging can reduce such issues but is unsuitable for heterogeneous or dynamic samples ubiquitous in biology, chemistry, and materials sciences. Here, we develop a phase retrieval-based cryo-ET method, PhaseT3M. We experimentally demonstrate its application to an approximately 7 nm Co3O4 nanoparticle on an approximately 30 nm carbon substrate, achieving a maximum resolution of 1.6 Å, surpassing conventional limits using standard cryo-TEM equipment. PhaseT3M uses a multislice model for multiple scattering and Bayesian optimization for alignment and computational aberration correction,...

Characterizing the vertical structure of forests in the Brazilian Amazon

Tue, 10 Feb 2026 00:00:00 +0000

Little is known about the structure of tropical forests despite its critical role in the provisioning of ecosystem services. Here we assess the vertical structure of forests in the Brazilian Amazon with a large-scale airborne LiDAR dataset. We show that fire has greater impact in the lowest forest strata, differently from selective logging and windthrow. We also find that secondary forests quickly recover or even exceed reference areas at the 1-10 m height stratum but that full recovery for the 20-30 m height stratum has not been achieved even after 35 years. Our modeling results suggest that proximity to roads, elevation, precipitation, soil pH, and proportion of sand in the soil are the most important predictors of forest structure. Finally, we identify 5 forest structural types (FSTs) and use them to visualize the spatial distribution of forest structure. This study provides important information for forest monitoring, management, and conservation.

A ModEx Framework for Watershed Subsurface Investigation With Limited Geophysical Data Using Machine Learning and Hydrologic Modeling

Thu, 5 Feb 2026 00:00:00 +0000

Abstract Subsurface heterogeneity influences watershed hydrology strongly but remains difficult to characterize at catchment scales with sparse and costly field data. Geophysical surveys such as electromagnetic induction (EMI) provide local spatial subsurface images yet scaling them to watershed scales and converting EMI‐derived resistivity into hydraulic properties remains a challenge. We present a Model–Experiment (ModEx) framework that integrates limited EMI data with machine learning (ML) and hydrologic modeling to improve process representation and guide field investigations. Sparse EMI surveys were scaled to the catchment scale using a Random Forest model, and the resulting resistivity fields were combined with nearby borehole constraints to parameterize a hydrologic model. The EMI‐informed hydrological simulations improved predictions of streamflow sustained by subsurface flow and shallow saturation patterns. By combining EMI data and ML with hydrologic modeling, the ModEx...

Microbial inoculants and invasions: a call to action

Wed, 28 Jan 2026 00:00:00 +0000

Microbial inoculants are increasingly used for beneficial purposes in agriculture, bioremediation, and medicine, but they can carry risks of generating invasive microbes. Here, we present a roadmap for guarding against these invasions, proposing developing (i) coherent mechanistic understandings of how microbial inoculants can effect invasions, (ii) predictive models forecasting microbial invasion risks, and (iii) effective management strategies. To guide mechanistic understandings, we distill 17 guiding hypotheses. For predictive modeling, we highlight data collection needs and qualitative approaches. For management strategies, we stress the importance of accurately weighing the risks against benefits. The unified approach presented here provides a route toward an effective research and management infrastructure for microbial inoculants in order to avoid potentially catastrophic microbial invasions.

SeaFOAM: A Year-Long DAS Deployment in Monterey Bay, California

Wed, 28 Jan 2026 00:00:00 +0000

Abstract Distributed acoustic sensing (DAS) is being explored in a variety of environments as a promising technology for the recording of seismic signals in dense array configurations. There is a particular interest for deploying DAS arrays on the ocean floor, presenting formidable challenges for conventional seismology. Taking advantage of the availability of a dark fiber on the Monterey Bay Accelerated Research System (MARS) 52 km offshore cable at Monterey Bay, California, in July 2022, we installed a DAS interrogator at the shore end of the cable with the intention of acquiring continuous data for a period of one year. Here, we describe the experiment and present examples of observations over the first six months of the deployment.

The Global Spectra-Trait Initiative: A database of paired leaf spectroscopy and functional traits associated with leaf photosynthetic capacity