2026-11-13T06:11:27Z http://oai-pmh.copernicus.org/oai.php

oai:publications.copernicus.org:wesd148321 2026-11-12 wesd

Thomas, Philipp Silva Shimonishi, Marco 2026-11-12 Text application/pdf https://doi.org/10.5194/wes-2026-213 eISSN: 2366-7451 eng

oai:publications.copernicus.org:wesd148309 2026-11-12 wesd

Leuthold, Rachel Schutter, Jochem Crawford, Curran Gros, Sébastien Diehl, Moritz 2026-11-12 Text application/pdf https://doi.org/10.5194/wes-2026-211 eISSN: 2366-7451 eng

oai:publications.copernicus.org:wes134898 2026-11-12 wes

White, Craig Cândido, José Frost, Ciaran This study assesses the economic viability of commercial-scale floating offshore wind farms in Portugal under a range of contract for difference (CfD) mechanisms. A techno-economic model simulated financial revenues using synthetic time wind and spot price data, under varying CfD mechanisms and metocean conditions for 36 sites off the Portuguese coastline. Results are split into levelized cost of energy, net present value, and internal rate of return and are influenced by a range of sensitivity analyses that help define the financial setting for successful floating offshore wind projects, including CfD mechanisms varying in type, value, and duration. Results indicate that floating offshore wind shows potential in Portugal, but only with strong financial support, with outcomes heavily influenced by site characteristics, wind regime, and economic conditions.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/wes-11-4237-2026 eISSN: 2366-7451 eng

oai:publications.copernicus.org:wcd141655 2026-11-12 wcd

Zhong, Wogu Ting, Mingfang Wu, Zhiwei Abnormal temperature fluctuations during spring can substantially impact vegetation growth, agricultural productivity, and ecosystem stability. However, the physical processes underlying year-to-year variations in the evolution of North American spring temperature anomalies remain poorly understood. Here, we apply Season-reliant Empirical Orthogonal Function (S-EOF) analysis to identify the leading modes of spring temperature evolution over North America. We focus on the first two modes here, which differ from conventional responses to winter El Niño–Southern Oscillation (ENSO) and are instead linked to distinct evolutions of tropical sea surface temperature (SST). The first mode (S-EOF1) features rapidly decaying Eastern Pacific (EP) ENSO-like SST anomalies from winter to spring and the emergence of tropical North Atlantic (TNA) SST anomalies, accompanied by a persistent north–south temperature dipole over North America. This mode is jointly influenced by the North Pacific Oscillation (NPO) and TNA-related North Atlantic circulation anomalies. In contrast, the second mode (S-EOF2) is associated with more persistent Central Pacific (CP) ENSO-like SST anomalies and the absence of TNA SST anomalies, together with evolving temperature patterns with temporal phase reversals across large parts of North America. This mode is primarily associated with the North Pacific (NP) pattern, whose influence may be further amplified by persistent CP ENSO-like SST anomalies. Dominance analysis further quantifies the relative contributions of tropical SST and midlatitude circulation patterns. These findings highlight the critical roles of ENSO decay rate and spatial structure, TNA SST variability, and their coupling with midlatitude circulation in shaping distinct spring temperature evolution patterns, with important implications for improving seasonal prediction.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/wcd-7-2251-2026 eISSN: 2698-4016 eng

oai:publications.copernicus.org:tc140559 2026-11-12 tc

Gu, Fengguan Liu, Changwei Han, Bo Yang, Qinghua Liu, Jiping Snow plays a critical role in the mass and energy balance of sea ice through its insulating properties and high albedo. Based on observations from the Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign, we assess the influence of two Icepack snow redistribution parameterizations, bulk redistribution and blowing snow redistribution, on snow thickness simulations using the Icepack column model. Our results show that, without snow redistribution, snow thickness is overestimated in winter and spring. The bulk redistribution scheme slightly reduces snow accumulation, while the blowing snow scheme further increases agreement with observations but still overestimates snow accumulation during major snowfall events. Sensitivity experiments indicate that setting p=4, corresponding to a ridged-to-level snow mass ratio of 5, in the bulk redistribution scheme yields the best agreement with snow observations (mean absolute error (MAE) reduced by approximately 73 % relative to the baseline bulk experiment). In the blowing snow scheme, the snow erosion coefficient is treated as an effective tuning parameter. When observed sea ice concentration is prescribed, setting the snow erosion coefficient to

2.4 \times 10^{- 5}

produces simulated accumulated snow loss to leads consistent with observations and improves the simulated snow thickness (MAE reduced by approximately 51 % relative to the original blowing snow experiment). This study provides new insights into snow thickness simulation and the parameterization of snow redistribution, offering valuable guidance for improving modeling of snow thickness on Arctic sea ice.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/tc-20-6521-2026 eISSN: 1994-0424 eng

oai:publications.copernicus.org:tc139082 2026-11-12 tc

Nguyen, Alexander L. Lopez, Cesar G. Melara-Valle, Jennifer Ross, Eliza Bradley, Alexander S. Limbeck, Maggie R. Masteller, Claire C. Michaelides, Roger J. Thermokarst lakes are critical components of Arctic carbon cycling, yet their ice phenology remains poorly characterized at regional scales. We present the first comprehensive analysis of ice-on and ice-off timing across 30 774 lakes on the Alaska North Slope using Sentinel-1 synthetic aperture radar (SAR) classified by a Random Forest (RF) model trained using labels derived from Sentinel-2 optical imagery and ERA5 temperature data for the period 2019–2023. Our RF classifier achieved 94 % accuracy for ice state detection, enabling phenology retrieval for 97 % of lake-years. Results revealed a mean ice-free period of 114 d (standard deviation = 25 d), with ice-off occurring at day-of-year 159 (8 June) and ice-on at day-of-year 273 (30 September). Spatial analysis demonstrated strong latitudinal control on ice phenology, with ice-free duration decreasing by 23 d per degree northward. Lake morphology (area, circularity, convexity, and shoreline development index) showed modest but significant effects on ice timing after controlling for latitude effects, with shoreline development index and convexity each contributing ∼ 3 d variation across typical lake ranges. Comparison of the RF model and simplistic accumulated degree-day (ADD) model-detected ice phenology yielded a convincing match, where the offsets in ice phenology between the models fell within twice the per-detection observation gap for approximately 80 % of the lakes. Furthermore, these offsets exhibited the same strong latitudinal control and negligible effects of lake morphology. These lake-specific phenology dates provide timing and duration constraints for future methane studies using high-resolution sensors and provide baseline phenology data essential for understanding how continued Arctic warming will affect thermokarst lake dynamics and associated carbon cycle feedbacks.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/tc-20-6501-2026 eISSN: 1994-0424 eng

oai:publications.copernicus.org:nhess140400 2026-11-12 nhess

Machado, Sandro Lemos Santana, Guilherme Barbosa Carvalho, Miriam de Fátima Oliveira, Jailma Santos de Souza Karimpour-Fard, Mehran Perrone, Elio Municipalities worldwide struggle with slope instability, a particularly pressing issue in cities such as Salvador, Brazil, where rugged terrain, escarpments, and complex geology create a high risk of instability. The complexity of the problem is evident in the variability of terrain properties, the bedrock’s inherited structural features, and anthropogenic action. This range of variables makes it well-suited to machine learning (ML) approaches for instability prediction. Although ML has experienced an impressive recent boost, only a few cases have applied ML to real-world instability events. In this paper, a data bank of hydromechanical properties of soils is used in conjunction with a digital terrain model (DTM) and different geo-referenced information, including rainfall, vegetation coverage, geological structures, sewage collection/treatment status, and residential density, to predict the occurrence of soil mass movements and related emergency calls to the municipality from the population living in risk areas. 13 522 emergency calls were considered during the period from 2020 to 2025. Excellent predictive performance, with an R²≈ 0.98 consistently across both the validation and testing phases, was obtained in this original study. This strong result underscores the viability of machine learning as a powerful tool for this kind of problem, particularly within municipal warning systems.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/nhess-26-5753-2026 eISSN: 1684-9981 eng

oai:publications.copernicus.org:msd147799 2026-11-12 msd

Hu, Zhongpo Cui, Quanwei Zhou, Jianxing Zhou, Hanxin 2026-11-12 Text application/pdf https://doi.org/10.5194/ms-2026-188 eISSN: 2191-916X eng

oai:publications.copernicus.org:gmd142687 2026-11-12 gmd

Raoult, Nina Pinnington, Ewan Santa Cruz, Mario Pinault, Florian Raoult, Baudouin Zelenka, Natalie Arduini, Gabriele Balsamo, Gianpaolo Boussetta, Souhail Chantry, Matthew Rosnay, Patricia Dueben, Peter Rüdiger, Christoph A stand-alone emulator of ECMWF's land surface scheme (ecLand) has been developed. This emulator, aiLand, uses a multi-layer perceptron architecture, chosen for its balance of accuracy and efficiency and for its differentiability, which is crucial for integration into data assimilation and parameter estimation systems. In this study, we introduce a two-stage learning framework that leverages both synthetic land surface model simulations and real-world observations. We first pretrain the surrogate on extensive ecLand outputs to capture the core dynamical behaviour of key land surface states, evaluating its accuracy, long-term stability, and transferability across variables, depths, and climates. We then fine-tune the pretrained model on in situ eddy-covariance flux observations for selected diagnostic variables, validating against independent flux-tower sites. The pretrained emulator reproduces ecLand's prognostic soil state with a 90 d RMSE of 1.19 K for surface soil temperature and 0.014 m³ m⁻³ for surface soil moisture, and remains stable over continuous 4-year autoregressive integrations. A single globally trained model outperforms regime-specialist baselines in cross-regime transfer, with residual errors concentrating in snow-insulated cold regimes where an insulating snowpack decouples the soil from atmospheric forcing. Fine-tuning on FLUXNET observations reduces latent heat flux RMSE by 30 % and sensible heat flux by 20 % at validation sites, while preserving prognostic state integrity and improving the physical consistency of the surface energy budget: per-site Bowen ratio error drops by 42% and energy balance closure residuals fall from 13.4 to 3 W m⁻² and below. These results demonstrate that combining physics-based pretraining with observation-based fine-tuning provides a flexible pathway for building accurate, stable, and differentiable land surface emulators suitable for data assimilation and coupled modelling applications.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/gmd-19-10763-2026 eISSN: 1991-9603 eng

oai:publications.copernicus.org:gh133539 2026-11-12 gh

Bertschi, Denise Bathla, Nitin Amid an ongoing public reassessment of the historical legacy of Switzerland's colonial entanglements, this article examines the contested production of knowledge in Swiss geography and urban studies, focusing on the policing of the academy and the epistemic ruptures it has provoked. Tracing historical continuities from radical student movements of the 1980s to recent mobilisations with Black Lives Matter and solidarity with Palestine, we show how moments of dissent have opened spaces for challenging Switzerland's colonial amnesia and racial denial. At the same time, we argue that the political–economic orientation of Swiss critical urban studies, despite its powerful critiques of capitalist urbanisation, has often left the colonial and racial conditions of urbanisation insufficiently examined. Drawing upon historical concepts such as “colonialism without colonies” and “raceless racism”, we conceptualise two mutually reinforcing structures of disavowal: the separation of Swiss modernity and prosperity from colonial histories and the denial of race as an operative social relation despite the persistence of racialised inequalities. This conceptual synthesis enables Swiss urbanisation to be understood relationally through its connections to colonial extraction, racialised mobility, labour segmentation, and global regimes of accumulation. We use postcolonial urban studies not to designate a bounded subfield or category of cities but as a critical practice for reworking the histories, concepts, and methods through which urbanisation is understood. We conclude by advancing an agenda for postcolonial urban studies in and from Switzerland organised around three orientations, namely unmasking space, unearthing extractive geohistories, and unsilencing the everyday, which make racialised spatial relations perceptible, reconstruct the extractive geohistories of urbanisation, and recognise everyday struggles as sites of theorisation.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/gh-81-767-2026 eISSN: 2194-8798 eng

oai:publications.copernicus.org:essdd146691 2026-11-12 essdd

Shi, Gaosong Gobin, Anne Wei, Zhongwang Yuan, Hua Li, Qingliang Shangguan, Wei Dai, Yongjiu 3 m⁻³ relative to the SoilGrids-driven experiment and increased the spatial correlation with adjusted ERA5-Land from 0.741 to 0.802. GSDEv2 thus provides a vertically harmonized and spatially detailed soil resource for regional-to-global Earth system applications. The GSDEv2 dataset is freely available at https://doi.org/10.11888/Terre.tpdc.303613 or https://www.scidb.cn/s/my2aea (Shi et al., 2026).]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/essd-2026-770 eISSN: 1866-3516 eng

oai:publications.copernicus.org:essdd147311 2026-11-12 essdd

Bai, Xueru Zhang, Mingyuan Zha, Jinlin Huang, Anning Zhu, Xinsheng Tang, Jian Zhao, Deming Wu, Jian −1. Beyond NSWS, the dataset also includes surface roughness, land cover type, elevation, latitude, and longitude to support diverse user applications and independent evaluation. This study aims to provide a robust, high-resolution data foundation for advancing understanding of wind variability and its broader impacts across Earth system sciences. SgriWind-CN is publicly available at https://doi.org/10.5281/zenodo.22812484 (Bai et al., 2026).]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/essd-2026-806 eISSN: 1866-3516 eng

oai:publications.copernicus.org:essdd145017 2026-11-12 essdd

O, Sungmin Orth, Rene Dorigo, Wouter 2026-11-12 Text application/pdf https://doi.org/10.5194/essd-2026-620 eISSN: 1866-3516 eng

oai:publications.copernicus.org:essd141103 2026-11-12 essd

Segura, Hans Wing, Allison A. Kalesse-Los, Heike Carrasco, Ruben Ruppert Jr., James H. Trosits, Anna Nuijens, Louise Ament, Felix Blandfort, Daniel Bell, Michael M. Bosser, Pierre Colón-Burgos, Delián George, Geet Habib, Joelle Horstmann, Jochen Jansen, Friedhelm Kluft, Lukas Kopte, Robert Möller, Klas Ove Paschou, Peristera Schmidt, Hauke Schlundt, Michael Serikov, Ilya Stelzner, Martin Thompson, Elizabeth J. Wimmer, Werenfrid Dengler, Marcus Klocke, Daniel As part of BOWTIE (German: Beobachtung von Ozean und Wolken – Das Trans ITCZ Experiment), the German research vessel FS Meteor navigated the moist tropics of the Atlantic Ocean for 40 d in summer 2024, with an east-west trajectory. The journey started in the port of Mindelo, Cape Verde, on 16 August, and finished in the port of Bridgetown, Barbados, on 24 September. The objective was to measure properties of the atmosphere, upper ocean, and air-sea interface within the Intertropical Convergence Zone (ITCZ), under a variety of wind, convection, and sea surface temperature regimes. Using a set of 29 instruments/platforms, BOWTIE sampled the near-surface conditions of the atmosphere and ocean with high temporal resolution. This included continuous measurements of: the 2D wind field within the lowest 2 km of the atmosphere, near-surface ocean currents, cloud and precipitation properties. Profiles of the ocean state and atmospheric thermodynamics and kinematics were obtained both continuously and at discrete intervals. Furthermore, biochemical properties of the upper ocean were sampled during dedicated stations. Complementing BOWTIE observations, FS Meteor hosted further dedicated field campaigns for 3D cloud and precipitation properties, as well as intensive measurements of the atmospheric boundary layer. This manuscript provides an overview of the extensive instrumentation and data collected during BOWTIE. In addition, it addresses two key aspects based on these observations. First, it examines the range and uncertainties of selected quantities measured by multiple instruments, including column-integrated water vapor, rain detection, surface ocean currents, and sea surface temperature. Second, it illustrates the diversity of sampled weather regimes through two representative cases: calm doldrum conditions and a gusty, precipitating convective state. The links and DOIs of the data sets presented in this study are listed in the code and data availability section.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/essd-18-8275-2026 eISSN: 1866-3516 eng

oai:publications.copernicus.org:amt145132 2026-11-12 amt

Witschas, Benjamin Köster, Elina Kleinert, Oliver Lemmerz, Christian Lux, Oliver Rahm, Stephan The HEterodyne Detection Wind lIdar Gadget (HEDWIG) is a new airborne Doppler wind lidar developed at the German Aerospace Center (DLR) for high-resolution observations of atmospheric wind profiles. The instrument operates at an eye-safe wavelength of 1617 nm. A newly developed double-wedge scanner provides rapid and flexible beam steering, enabling both conical scanning for horizontal wind retrieval and parallel nadir-pointing observations for direct measurements of the vertical wind component. The complete instrument, including laser transmitter, receiver, scanner, data acquisition system and wind retrieval chain, is described in detail. Particular emphasis is placed on the optical and mechanical design of the scanner, the synchronized data acquisition, as well as the retrieval algorithms for line-of-sight (LOS) Doppler velocities and atmospheric wind vectors.

The instrument was successfully deployed for the first time aboard the German research aircraft HALO during the North Atlantic Waveguide, Dry Intrusion and Downstream Impact Campaign (NAWDIC) in winter 2026. Surface-return analyses demonstrate a systematic wind speed error below 0.1 m s⁻¹ and a random error of about 0.2 m s⁻¹ for single LOS measurements under high-SNR conditions. First airborne observations further demonstrate the capability of HEDWIG to retrieve horizontal wind vectors together with high-resolution vertical wind profiles. The instrument therefore provides a unique observational capability for airborne studies of atmospheric dynamics as well as for satellite instrument validation as for instance the Doppler velocity products of the cloud profiling radar on EarthCARE, but also for future missions as WIVERN and Aeolus-2.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/amt-19-7343-2026 eISSN: 1867-8548 eng

oai:publications.copernicus.org:amt141076 2026-11-12 amt

Dingemanse, Johannes Dirk Kimo, Israel Gebresilasie Ibrahim, Awel Haji Demeke, Yared Godine Kalbe, Nazrawit Samuel Isaxon, Christina Eriksson, Axel C. Ethiopian air pollution is understudied yet highly relevant considering population size and source abundance including solid fuel cooking, small scale waste burning and vehicle fleet. Low-cost PM_2.5 sensors can be used to mitigate this by mapping pollution exposure. We report on indoor and outdoor measurements with Sensirion sensors SPS30 and SEN55, the former extensively validated in literature, the latter not. We evaluate their use in Arba Minch, population ca. 200 000. In addition to sensor inter and intra comparison we benchmark the low-cost sensors against gravimetry. Furthermore, a separate Swedish outdoor dataset is included to extend the range of particle types and loadings and evaluate relative humidity (RH) effects using a reference-equivalent monitor (Palas FIDAS).

We found that the SEN55 consistently reports values 6 %–10 % higher than the SPS30; once this systematic offset is corrected, the sensor types are functionally identical with high precision (coefficient of variation ≤7.7 %, between-sampler uncertainty ≤1.7 µg m⁻³). Both sensors demonstrated high stability across repeated high-concentration events (>1000 µg m⁻³). While the SEN55 exhibits digital truncation at 6553.4 µg m⁻³, we find that measurements beyond the 1000 µg m⁻³ manufacturer specification remain meaningful and essential for accurate mass estimation in biomass-burning environments. The impact of relative humidity was small and consistent across both sensor types.

Our study shows that the SPS30 and SEN55 – when calibrated under circumstances of use – are stable and accurate instruments (indoor and outdoor accuracy error ≤22 %, outdoor expanded uncertainty ≤15 % in comparison to gravimetric measurements). Pragmatic, large-scale low-cost monitoring supported by mobile gravimetric validation offers the most viable path toward mitigating air pollution exposure in resource-constrained settings.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/amt-19-7305-2026 eISSN: 1867-8548 eng

oai:publications.copernicus.org:amt142878 2026-11-12 amt

Fahlen, Jay E. Brodrick, Philip G. Thompson, David R. Thorpe, Andrew K. Green, Robert O. The detection and quantification of methane and other trace gas emissions using remote sensing with imaging spectroscopy is an increasingly important tool for understanding local, regional, and global emissions. Traditional algorithms for quantifying the emission rate often rely on user-determined, instrument-dependent parameters and arbitrary plume boundaries. In this paper we present a new algorithm to estimate the emission rate based on a statistical inversion of a physical, Gaussian plume model that does not depend on such parameter choices or plume boundaries, termed SPIIRE. The method fully exploits instrument noise models, incorporates surface-albedo and atmospheric effects present in gas enhancement imagery, and is well suited for operational use. We present simulation results showing improved noise resilience, demonstrate performance against controlled-release experimental data using AVIRIS-3 and EMIT, and provide multiple examples using EMIT. The controlled-release results show improved performance of SPIIRE relative to an IME-based method. We then show how the model can be extended to complex scenes having overlapping plumes and to spatially-distributed sources like landfills.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/amt-19-7217-2026 eISSN: 1867-8548 eng

oai:publications.copernicus.org:amt139307 2026-11-12 amt

Illson, Stuart J. Barkjohn, Karoline K. In recent years the use of air sensors has rapidly expanded across North America to measure fine particulate matter (PM_2.5), particularly in response to increasing air quality impacts from wildland fire. With the benefit of enhanced spatial and temporal coverage, the scientific community and the public have come to rely on sensor networks as valuable sources of air quality information. With an increasing variety of sensor devices being deployed, there is a need to validate and harmonize PM_2.5 data between different device types. While significant attention has been given to calibration and correction equations to improve the accuracy of a given sensor's measurement, there is a need to develop tractable and generalizable methods of identifying malfunctioning or unreliable sensors, given the maintenance, siting, and operation of many of these devices is unknown. In this paper, we propose a method of identifying outlier PM_2.5 sensors, defined as those whose measurements deviate strongly from other local measurements due to hardware faults or to hyper-local environmental conditions that are not representative of typical ambient air quality conditions. While detecting outliers during typical conditions is a fairly straightforward task, detecting outliers during smoke events is challenging due to real, erratic shifts in PM_2.5 concentrations. Here, we present a novel method of detecting outliers within sensor networks by combining measures from information theory and machine learning. We first define a tuneable, rule-based detection function that balances the Shannon entropy of a local network against the information content of an individual sensor's measurement. We then use this function, together with additional information-theoretic and short-term temporal features, to train a gradient-boosted decision tree for automated outlier detection. Hourly PM_2.5 measurements from various device types were collected for 11 smoke events across North America in 2024 and 2025, and a stratified sample of sensor data were perturbed to simulate 5 commonly seen faults. In each of these cases, we assessed each method's ability to detect the simulated faults. We demonstrate that either of these methods can act as an adjustable data validation procedure when applied to both real-time air quality reporting and retrospective analysis for smoke impacts.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/amt-19-7359-2026 eISSN: 1867-8548 eng

oai:publications.copernicus.org:amt139154 2026-11-12 amt

Kobayashi, Takahisa Masuda, Kazuhiko Yamauchi, Hiroshi Adachi, Ahoro This paper describes a physically-based algorithm for estimating the mass-weighted raindrop diameter (D_m) and the corresponding Doppler velocities (V_D) which are the radar reflectivity-weighted terminal velocities of the raindrops. The algorithm exploits the attenuation-corrected radar reflectivity (Z_e) and the specific attenuation (k) observed by Ku- and W-band space-borne Doppler radars and estimate D_m assuming a specified drop size distribution DSD. The estimated D_m were examined using a Monte Carlo model which evolves DSDs by coalescence and breakup in a convective rain as well as measured data with a disdrometer. A detailed error analysis is also presented in the retrieved D_m arising from the measurement errors. While discrepancies between the assumed DSDs (DSD_LUT) and actual DSDs introduce errors in the estimated values, the errors were generally small for small D_m values. The uncertainties related to the variability of DSD were reduced by selecting an appropriate DSD_LUT using the dependence of Z–R relationship (R: rain rate) on D_m. Since k is the DSD-dependent value in the W-band, the influence of the DSD can be partially mitigated but is limited. Utilizing parameters representing the shape of DSD by k, Z_e and V_D offer the potential to reduce the DSD-related errors furthermore.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/amt-19-7255-2026 eISSN: 1867-8548 eng

oai:publications.copernicus.org:amt140057 2026-11-12 amt

Gatou, Maria Christina Lipponen, Antti Leskinen, Ari Tiitta, Petri Filioglou, Maria Shang, Xiaoxia Pätsi, Sanna Saarto, Annika Roponen, Marjut Giannakaki, Elina Komppula, Mika Bioaerosols, such as pollen grains, play an important role in air quality, human health and atmospheric processes. However, their vertical distribution within the boundary layer remains insufficiently researched. In this study, we investigate the vertical profiles of pollen concentrations between 4–272

m a . g . l .

at the Vehmasmäki station in Eastern Finland. In situ measurements with optical pollen sensors at 4, 115, and 272 m were conducted simultaneously with ground-based observations from a Hirst–type volumetric air sampler and a Cloud Droplet Analyzer. Multiple campaigns were conducted during pollen seasons between 2021–2024, focusing on the dominant pollen types, i.e. birch and pine pollen. The three optical pollen sensors showed strong agreement during the intercomparison period (R²≥0.91), demonstrating good consistency among the instruments. The Cloud Droplet Analyzer measurements in the 20–100 µm size range showed that pollen dominated the measured concentrations of coarse particles during the intensive pollen periods. Polarization scatter plots for birch and pine pollen revealed distinct optical signatures, during predefined intensive pollen periods between 2021–2023, consistent with laboratory results. Furthermore, we assess how background fine-mode aerosol influences these signatures. During a major birch pollen episode in May 2024, pollen concentrations decreased with height. These vertical profiles were compared with predictions from the System for Integrated modeLling of Atmospheric coMposition (SILAM), which reproduced the vertical distribution from the observations, but systematically overestimated pollen concentrations at all heights. Moreover, a machine–learning classification approach combining optical pollen sensor measurements and meteorological variables demonstrated the possibility of identification of dominant pollen types. Our results demonstrate the feasibility of optical pollen sensors for continuous, real–time monitoring of dominant pollen taxa in boreal regions, from measurements in Vehmasmäki.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/amt-19-7387-2026 eISSN: 1867-8548 eng

oai:publications.copernicus.org:amt138576 2026-11-12 amt

Schooling, Chlöe N. Feng, Liang Woodwark, A. Jerome P. Arnstein, Alexander Green, Paul D. Palmer, Paul I. Satellite measurements have revolutionized methane monitoring, yet persistent clouds and aerosols often limit global-survey instruments like TROPOMI in the tropics. This study evaluates the potential of the Near Infrared Multispectral Camera for Atmospheric Methane (NIMCAM), a high-resolution instrument (60 m pixels) designed for point sources, to quantify large-scale diffuse emissions across tropical Africa. Through Observing System Simulation Experiments (OSSEs), we compare an in-orbit demonstrator and small NIMCAM constellations (3 and 5 satellites) against synthetic data from the TROPOMI (TROPOspheric Monitoring Instrument) instrument. Using Sentinel-2 cloud probabilities and downscaled MODIS aerosol optical depth products, we find that NIMCAM's finer spatial resolution significantly increases clear-sky data yields. A 5-satellite constellation provides up to six times more clear-sky observations than TROPOMI. As masking criteria for clouds and aerosols become more stringent, the ratio of NIMCAM to TROPOMI random error (

σ_{NIM} / σ_{TROP}

) decreases. This occurs because TROPOMI's coarser footprint leads to a more rapid loss of data under strict thresholds. Using the GEOS-Chem chemical transport model and an ensemble Kalman Filter, we demonstrate that NIMCAM observations offer substantial added value in resolving tropical emissions. NIMCAM achieves higher uncertainty reduction than TROPOMI, particularly in regions and seasons where cloud and aerosol loading restrict coarser instruments. Our findings support using high-resolution methane technology to complement global surveys in monitoring diffuse tropical emissions.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/amt-19-7279-2026 eISSN: 1867-8548 eng

oai:publications.copernicus.org:aab130387 2026-11-12 aab

Abo Egila, Nahed S. H. Dosoky, Waleed M. Ahmed, Mohamed H. Zahran, Soliman M. Awad, Ahmed Sh. Salah, Ayman S. El-Kholy, Mohamed S. Abdelhaseib, Maha Habib, Mohamed M. Alagawany, Mahmoud Azzam, Mahmoud M. The goal of the present study was to discover the probable impact of sunflower oil (SUNO), linseed oil (LINO), and canola oil (CANO) with or without vitamin E treatments on the productive parameters and egg yolk lipid metabolism of quail eggs. In a completely randomized design, this trial was conducted as a 3 × 2 factorial trial with three sources of vegetable oils (SUNO 3 %, LINO 3 %, and CANO 3 %) and two types of vitamin E (0 and 250 mg kg⁻¹ diet) in six treatments. A total of 192 female Japanese quails, 10 weeks of age, were randomly allocated to six dietary treatments, with 32 quails per treatment. Each treatment was further divided into four replicates of eight hens each. The experiment lasted for 10 weeks (10–20 weeks of age). The group of quails that received diets with canola oil at 15–20 weeks of age and linseed oil with vitamin E throughout the trial period (15–20 weeks of age) achieved the highest egg weight. The egg yolk malondialdehyde level was decreased at 15 and 20 weeks of age and after 15 and 30 d of storage in the refrigerator because of the addition of various vegetable oil sources in the diets. In summary, the productive criteria, lipid metabolism, and antioxidant properties of egg yolks in Japanese quail breeders (Coturnix Japonica) were all positively impacted by the combination of linseed oil, canola oil, and vitamin E during the laying period. Dietary supplementation with SUNO, LINO, and CANO improved the nutritive value of eggs by favorably modulating antioxidant stability and yolk metabolism lipids during refrigerated storage for 15 and 30 d, potentially participating in cardiovascular health and a more favorable dietary fatty acid profile.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/aab-69-665-2026 eISSN: 2363-9822 eng

oai:publications.copernicus.org:acp144021 2026-11-12 acp

Cai, Runlong Xu, Shimeng Kerminen, Veli-Matti Kulmala, Markku New particle formation (NPF) is a major source of global aerosol number concentration yet its contribution to aerosol mass remains unclear. Here we propose a regime framework for NPF mass contributions using aerosol dynamic simulations constrained by atmospheric measurements. We show that new particles can contribute more than 10 µg m⁻³ to particle mass under conditions characterized by high initial new particle concentrations, high condensable vapor production rates, and low background condensation sink (CS_bg). Among these influencing factors, the initial CS_bg governs NPF mass contribution under the simulation conditions: NPF contributes significantly to aerosol surface area and mass at an initial CS_bg of ∼ 0.001 s⁻¹ (regime I), while its contribution becomes negligible when CS_bg exceeds 0.01 s⁻¹ (regime III). Results show that NPF events in urban Beijing occur mostly in a transition regime (initial CS_bg 0.001–0.01 s⁻¹, regime II), in which the NPF mass contribution is also modulated by the mass accommodation coefficient of background particles, while events at a Finnish forest site fall in regimes I and II. Our simulations suggest that NPF mass contribution in urban environments with a declining CS_bg will shift toward regimes I and II. This indicates that control of anthropogenic NPF precursors may represent an effective strategy for present and future particulate matter pollution in urban environments, which warrants further investigation.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/acp-26-16003-2026 eISSN: 1680-7324 eng

oai:publications.copernicus.org:acp140609 2026-11-12 acp

Simon, David J. Schaefer, Jonas Hartmann, Jörg Kirbus, Benjamin Müller, Joshua Hartmann, Markus Wetzel, Bruno Köhler, Laura Jörss, Anna-Marie Weinhold, Kay Herber, Andreas Jurányi, Zsófia Henning, Silvia Roberts, Gregory C. Wendisch, Manfred Pöhlker, Mira L. Stratmann, Frank New particle formation (NPF) can impact the Arctic radiative energy budget since this region is particularly sensitive to changes in aerosol particle and cloud condensation nuclei concentrations. Prior measurements have predominantly investigated NPF in the Arctic atmospheric boundary layer (ABL), while vertically-resolved studies on newly formed aerosol particles remain scarce. Here, we present an analysis which suggests that NPF may take place throughout the entire lower Arctic troposphere. We have reached this conclusion by analyzing aerosol particle number size distribution data collected during a springtime aircraft campaign (BACSAM II) in the vicinity of Svalbard, the Fram Strait, and northern Greenland. We detected newly formed aerosol particles over distances of hundreds of kilometers, at various altitudes ranging from about 60 to 3900 m, and identified four atmospheric scenarios for their occurrence: newly formed particles in the free troposphere, in the ABL over sea ice, in the vicinity of clouds, and in the ABL over ocean with sea ice floes. Our results indicate that regional Arctic atmospheric processes as well as long-range transport may play key roles in the formation of new particles. In particular, we deduce that one possible mechanism leading to free tropospheric NPF could be associated with warm-air intrusions.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/acp-26-16047-2026 eISSN: 1680-7324 eng

oai:publications.copernicus.org:acp141421 2026-11-12 acp

Liang, Jiakun Gustafson Jr., William I. Caulton, Dana R. Small Griswold, Jennifer D. Aircraft observations are widely used to evaluate cloud simulations; however, their inherently localized sampling may not fully represent the domain-scale cloud properties resolved by large-eddy simulations (LES). This study quantifies how aircraft-like sampling strategies influence the representativeness of in-cloud cloud water content (CWC) derived from LES output. Using LASSO simulations for the ARM Southern Great Plains site (SGP), we emulate aircraft trajectories by prescribing multiple horizontal flight patterns (circle, diagonal, straight, combo, and zigzag) and vertical profiles (level-leg, sine wave, staircase, and zigzag) under different speed categories. Results show that sampling geometry substantially influences the degree to which aircraft-like measurements capture the magnitude and variability of domain-scale CWC. Sampling representativeness depends jointly on flight speed and trajectory geometry. For the level-leg, sine wave, and staircase vertical profiles, increasing flight speed generally improves agreement with the layer-restricted in-cloud domain mean by increasing spatial coverage and reducing sensitivity to localized heterogeneity. In contrast, the zigzag pattern does not show systematic improvement with speed because its phase-locked vertical–horizontal coupling constrains effective spatial coverage. Cloud-boundary analysis further indicates the tendency to underestimate cloud-top height, while cloud-base height is more consistently captured, with higher speeds reducing both bias and variability. These findings establish a systematic framework for interpreting aircraft-based cloud measurements in the context of LES output and highlight the importance of sampling strategies in assessing representativeness in model–observation comparisons.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/acp-26-16029-2026 eISSN: 1680-7324 eng

oai:publications.copernicus.org:acp141232 2026-11-12 acp

Yi, You Randel, William J. Pan, Laura L. Liu, Yi Fang, Shuangxi Cai, Zhaonan Campos, Teresa Gaubert, Benjamin Methane in the upper troposphere and lower stratosphere (UTLS) plays a critical role in atmospheric composition and radiative forcing, yet the processes governing its vertical structure and variability remain poorly understood. Here, we use high-quality satellite observations from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) to characterize the vertical structure and global seasonal behavior of methane in the UTLS, with emphasis on the role of Asian Summer Monsoon (ASM). In the ASM, a maximum in methane concentration occurs near the tropopause, at a higher altitude than the corresponding carbon monoxide maximum. The largest relative enhancement for methane – the difference between air inside and outside the anticyclone – occurs above the tropopause and extends poleward to the north. This behavior contrasts with carbon monoxide, which is confined within the anticyclone. The seasonal cycle of methane near the tropical tropopause peaks in boreal autumn, following the summer peak in surface fluxes and deep convection. This phase lag reflects the combined effects of ASM transport and subsequent large-scale redistribution following the breakdown of the anticyclone. Positive anomalies occur in the tropical lower stratosphere in boreal winter, consistent with the upwelling branch of the Brewer–Dobson circulation (BDC). Beyond the seasonal cycle, ACE-FTS data show a pronounced hemispheric asymmetry in lower stratospheric methane trends, consistent with reported changes in other long-lived trace constituents. Together, these results provide new observational evidence that ASM transport imprints a distinct methane structure above the tropopause and plays a key role in shaping UTLS variability on a global scale.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/acp-26-16013-2026 eISSN: 1680-7324 eng

oai:publications.copernicus.org:acp134742 2026-11-12 acp

Thiam, Mamadou Lamine Hourdin, Frédéric Grandpeix, Jean-Yves Rio, Catherine Coulon-Decorzens, Maëlle Cold pools, formed under clouds by the evaporation of precipitation, play a central role in maintaining and organizing atmospheric convection. It is suspected that their absence in climate models may lead to significant errors in the representation of convection, such as the premature convection extinction after sunset. The introduction of a cold pool parameterization into the LMDZ climate model has significantly improved the representation of convection, in particular its diurnal cycle. Thanks to this indirect evaluation, the parameterization of cold pool was retained in the further versions of LMDZ. However, no evaluation of the representations of cold pools themselves was done so far. This work provides for the first time such an evaluation based on Large Eddy Simulation (LES). The evaluation is done both on a case of radiative–convective equilibrium that allows the study of convective processes in a well-controlled and quasi-stationary framework, without the influence of large-scale dynamics, and on the time-dependent continental case AMMA (African Monsoon Multidisciplinary Analysis), representative of typical Sahelian conditions with local initiation during the afternoon. First, we evaluate the physical relationships underlying the cold pool model in the LES, then, in a second step, its behavior when coupled with the deep convection scheme in the single-column version of LMDZ. The analyses carried out demonstrate the relevance of the assumptions underlying the parameterization. The initial version actually captures the main characteristics of LES cold pools but also exhibits some biases. We show how substantial modifications to the cold pool scheme and a readjustment of certain free parameters helped reduce those biases significantly. The remaining flaws could be corrected by adding convective mixing through thermal plumes within the cold pools and by modeling the evolution of cold pools number density rather than imposing it.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/acp-26-15975-2026 eISSN: 1680-7324 eng

oai:publications.copernicus.org:egusphere148324 2026-11-12 egusphere

Simon, Leïla Nowak, Nora Andrews, Stephen J. Bauer, Michael Bell, David M. Brem, Benjamin T. Cavalli, Fabrizia Cheung, Rico K. Y. Decker, Zachary C. J. Hopkins, Jim R. Hüglin, Christoph Ivančič, Matic Keller, Alejandro Lavrič, Gašper Léonardis, Thierry Modini, Robin Lewis Putaud, Jean-Philippe Reimann, Stefan Rigler, Martin Salameh, Thérèse Steinbacher, Martin Vollmer, Martin K. Weingartner, Ernest Gysel-Beer, Martin Carbon closure and volatility studies are needed to better constrain atmospheric carbon, but are especially lacking in high altitude sites, as these environments can be challenging to access. During a measurement campaign from 16 August to 20 September 2022 at Jungfraujoch (3580 m.asl, Switzerland), gas- and particle phase carbon was characterized using a broad suite of instruments, including a thermo-denuder upstream of a time-of-flight aerosol chemical speciation monitor to investigate particulate organic carbon (pOC) volatility. As expected in summer, the Jungfraujoch was mainly under planetary boundary layer influence (PBLi), with some periods in the free troposphere (FT). Moreover, a Saharan dust event and two wildfire plumes were identified.

The composition of fine particles was dominated by organic aerosol mass for all conditions, and particulate carbon measurements by different techniques captured similar temporal variability but showed systematic differences in absolute concentrations, especially at low concentrations. pOC was dominated by semi-volatile organic carbon, and a substantial part of OC could partition between gas and particle phase depending on pOC concentration and ambient conditions. PBLi conditions, compared to FT, showed higher concentrations of both gas and particle phase compounds, higher contribution of short-lived VOCs and higher pOC volatility. In addition, the wildfires affected OC concentrations and composition and exhibited higher pOC oxidation state and lower inferred pOC volatility, coinciding with high m/z organic fragment signals. These findings contribute to a better understanding of the impacts of local and regional sources, and long-range transported plumes on free tropospheric carbonaceous compounds’ concentrations and properties.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6814 eISSN: eng

oai:publications.copernicus.org:egusphere148467 2026-11-12 egusphere

McDougall, Trevor J. Holmes, Ryan M. Gunn, Kathryn L. 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6924 eISSN: eng

oai:publications.copernicus.org:egusphere148447 2026-11-12 egusphere

Belgacem, Malek Kokoszka, Florian V. M. Cantoni, Carolina Schroeder, Katrin Chiggiato, Jacopo Sparnocchia, Stefania Fragiacomo, Elena Acri, Francesco Rovere, Marzia 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6912 eISSN: eng

oai:publications.copernicus.org:egusphere148436 2026-11-12 egusphere

Velásquez-García, Maria P. Pope, Richard J. Turnock, Steven T. Arnold, Steve R. Moore, David P. Doherty, Ruth M. Graham, Ailish M. Remedios, John J. Chipperfield, Martyn P. −1. Between Day 2 and Day 6, the TCHCOOH:TCCO ratio decays at ∼4.8 ± 0.8 % day⁻¹ as HCOOH is lost, then stabilises by Day 8. Box modelling based on the UK Chemistry and Aerosol model, initialised in the free troposphere (850 hPa) using in-plume observations, captures the increase in HCOOH:CO on the first day (4.4 % day⁻¹) but slightly underestimates it. The model identifies hydroxymethyl-methyl-α-lactone (HMML, an isoprene oxidation product), ethene, and acetylene as key HCOOH precursors. HMML might be influenced by vegetation-derived emissions. After Day 1, the simulated HCOOH:CO ratio declines smoothly (2.7 % day⁻¹), dominated by OH oxidation. This work demonstrates a novel approach that combines different observations and methods to investigate atmospheric chemistry in biomass burning plumes over week-long timescales.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6903 eISSN: eng

oai:publications.copernicus.org:egusphere148431 2026-11-12 egusphere

Wang, Jianyuan Yi, Wen Xue, Xianghui He, Maosheng Wu, Jianfei Ye, Hailun Chen, Tingdi Li, Jian Zeng, Jie Ding, Zonghua Li, Na Wang, Jian Vincent, Robert A. Reid, Iain M. Batista, Paulo P. Buriti, Ricardo A. Tsuda, Toshitaka Mitchell, Nicholas J. Dou, Xiankang 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6900 eISSN: eng

oai:publications.copernicus.org:egusphere148422 2026-11-12 egusphere

Yang, Yunkai Li, Baojie Zhang, Weimeng Zhao, Yongqi Liu, Junjie Gu, Wanglijing Liao, Hong 2.5) pollution is strongly influenced by ammonia (NH₃) emissions, particularly their high-frequency variation driven by nitrogen fertilization. However, the unavailability of daily fertilization dates renders the spatiotemporal distribution of fertilizer-induced NH₃ emissions unclear, thereby limiting the accuracy of NH₃ emission estimates and PM_2.5 prediction. We developed a new method that identifies daily fertilization dates from multisource satellite observations and quantifies daily NH₃ emissions using machine learning. The identified fertilization dates correlated well with reported fertilization dates (mean correlation coefficient R = 0.96). Total NH₃ emissions from major crop fertilization were estimated at 3.01 Tg in 2021. The 10 % of days with the highest emissions accounted for 33.11 % of the annual total, with an average of 31.15 Gg d⁻¹ on these days. The new inventory substantially improved the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulation of PM_2.5, reducing the average root mean square error (RMSE) by 35.34 % during typical fertilization events. These daily datasets enable a shift from annual emission controls to temporally targeted mitigation strategies, and suggest that optimizing fertilization timing could mitigate severe PM_2.5 pollution.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6894 eISSN: eng

oai:publications.copernicus.org:egusphere148401 2026-11-12 egusphere

Ding, Hao Baró Pérez, Alejandro Mastroianni, Nazario Neuberger, Almuth Ranjan, Rahul Mattsson, Fredrik Heikkinen, Liine Mansour, Karam Decesari, Stefano Lupi, Angelo Mohr, Claudia Zieger, Paul Riipinen, Ilona Ekman, Annica M. L. -3) generally enhances fog geometric height, optical depth, and liquid water path, effects that become substantially more pronounced when wet ARI are considered. Within the observed range of aerosol chemical composition, aerosol hygroscopicity (κ = 0.33–0.53) is the dominant chemical factor shaping the fog life cycle, while variations in black carbon content have a negligible effect. These results highlight the important role of wet ARI in understanding long-term fog trends and their responses to aerosol changes.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6876 eISSN: eng

oai:publications.copernicus.org:egusphere148391 2026-11-12 egusphere

Pramanik, Ankit Morlighem, Mathieu Azam, Mohd. Farooq 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6868 eISSN: eng

oai:publications.copernicus.org:egusphere148380 2026-11-12 egusphere

Nerozzi, Fabrizio Tomozeiu, Rodica n^−1/2 to the asymptotic limit of the score under the null, and the random-forecast reference of Antonio and Aitchison is this limit for their Bernoulli null when the forecast probability equals the mean observed fraction: a central value, not a percentile. Second, the mean FSS of corresponding forecasts rises steadily with the width, whereas discrimination is largest at a width set by the position error, 5–15 grid points of 2.2 km for cells displaced by up to their radius, and declines beyond it; restricting the windows to the interior of the domain roughly doubles that decline. Third, seasonal aggregation multiplies the separation by about √n, and the most discriminating width of the aggregated score stays at or next to that of a single day: it ranks forecasting systems of different capability, but does not increase the evidence carried by the score of any single forecast. Critical values are specific to the population verified and to the null against which the score is judged; for seasons the delta method gives an asymptotic approximation to them in closed form from the daily sums of the score, without simulation. The seasonal score evaluates a forecasting system; the single-case analysis shows at which scale the score of each of its forecasts carries most evidence.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6860 eISSN: eng

oai:publications.copernicus.org:egusphere148378 2026-11-12 egusphere

Sheikh, Maha Wiesmann, Samuel Perona, Paolo Ruiz-Villanueva, Virginia 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6858 eISSN: eng

oai:publications.copernicus.org:egusphere148362 2026-11-12 egusphere

Guillouët, Pascal Lampert, Astrid Canadillas, Beatriz −1 to −0.028 ⁻¹ in three evaluated heights. The small effect on the mean wind speed is consistent with the finding of Cañadillas et al. (2026), who analysed measurements over a longer period. LIDAR-derived turbulence intensity decreased by approximately 0.03 to 0.04 in absolute terms, although the contributions of motion compensation and wind-vector-reconstruction choices were not isolated. A simple correction based on the 10-minute mean platform heading yielded 10-minute wind directions close to those obtained with full motion compensation, with standard deviation differences below 0.71°. These findings support the practical use of this heading-based correction to obtain geographically referenced mean wind directions under the investigated conditions. Onboard meteorological observations provide a plausibility check for the corrected winds, but the absence of independent reference measurements at comparable heights prevents a full assessment of their accuracy. Together with the earlier assessment, this study provides a practical basis for refining the processing of lightship-based wind measurements and helps future users of the planned open-access dataset select correction methods suited to their temporal scales and applications.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6846 eISSN: eng

oai:publications.copernicus.org:egusphere148355 2026-11-12 egusphere

Wang, Min Shi, Haiyang 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6840 eISSN: eng

oai:publications.copernicus.org:egusphere148307 2026-11-12 egusphere

Kang, Wooseok Lee, Myong-In Kim, Kyu-Myong Boo, Kyung-On Chang, Pil-Hun Lee, Hyomee ERF_ari^SW) decreases systematically with increasing SSA, shifting from near-zero or positive values in lower-SSA, more absorbing models to negative values in higher-SSA, more scattering models. Applying an Aerosol Robotic Network (AERONET)-based observational constraint on SSA, 0.9543 ± 0.0060, gives a constrained Saharan ERF_ari^SW centered near zero at −0.66 W m⁻², with a 95 % interval of −3.87 to +2.53 W m⁻².

Grouping the models by SSA reveals two contrasting monsoon responses to the same dust-emission perturbation. Low-SSA models show stronger atmospheric heating over the Sahara, a deeper heat low, enhanced monsoon inflow, and increased Sahel rainfall, whereas High-SSA models show a weaker or opposite response and reduced rainfall. The associated cloud-radiative response forms a Sahel–tropical North Atlantic dipole. Propagating the SSA-based constraint on the ERF_ari^SW through the relationship between Saharan ERF_ari^SW and Sahel cloud-radiative response reduces its inter-model variance by about one third. Thus, an observable dust optical property constrains a significant part of the downstream monsoon and cloud-response uncertainty.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6804 eISSN: eng

oai:publications.copernicus.org:egusphere148263 2026-11-12 egusphere

Xu, Xu Zou, Xiaolei 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6771 eISSN: eng

oai:publications.copernicus.org:egusphere148120 2026-11-12 egusphere

Hendrickson, Lucy Vlahos, Penny Romero, Leonel 2 flux across the droplet size distribution over varying wind speed, sea state, and relative humidity (RH). Including force-balance acceleration reduces fall speed for all droplets with the greatest impact on droplets over 200 µm, with fall speed reductions up to 60 % for the largest drops. This change introduces competing effects at the individual droplet level, both increasing the size of droplets that undergo complete evaporation by 2–8 % under modeled conditions and also enhancing the CO₂ uptake of large cooling drops. However, the modest increase in the maximum evaporating droplet size of medium-sized droplets, which are numerous, has a substantially greater impact on the overall spray-driven CO₂ flux than the increase in CO₂ uptake by cooling spume droplets, which are comparatively rare. Moreover, the impact of fall-speed formulation is modulated by RH, with larger relative flux increases occurring at higher RH, where slower evaporation rates make droplets more sensitive to small changes in residence time. These combined effects drive an 18–26 % increase in net spray-driven CO₂ flux under modeled conditions. Fall-speed formulation is therefore an important source of uncertainty in spray-driven CO₂ flux estimates, particularly in the high-wind, developing-sea regime where spray dominates air–sea exchange.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6668 eISSN: eng

oai:publications.copernicus.org:egusphere148153 2026-11-12 egusphere

Ekman, Ellinoora Li, Xuefei Leppänen, Antti Aalto, Tuula Anttila, Jani Jauhiainen, Jyrki Laiho, Raija Lohila, Annalea Markkanen, Tiina Minkkinen, Kari Mäkipää, Raisa Ojanen, Paavo Peltoniemi, Mikko Putkinen, Anuliina Raivonen, Maarit 4) and CO₂ (heterotrophic respiration) fluxes at six Finnish forestry-drained peatlands with a process-based JSBACH-HIMMELI model. Specifically, our focus was on evaluating the model performance and identifying the sources of uncertainty across multiple sites by using measurement data over several years from each site. The model predicted key environmental variables adequately well at each study site. In addition, we found that the there was more between-site variation in the prediction accuracy with the simulated CH₄ fluxes (NMRSE 1.02–9.25) than with the simulated CO₂ fluxes (NMRSE 0.62–1.24). Our study highlights WTL as the primary source of uncertainty in simulating the CH₄ fluxes. The sites characterized by consistently deep WTL exhibited substantially better agreement between the model and measurement with the soil–atmosphere CH₄ fluxes (RMSE 0.69–1.02 nmol m^-2 s^-1), than sites characterized by higher WTL (RMSE 1.04–9.70 nmol m^-2 s^-1). These discrepancies at high-WTL sites were associated with high anaerobic respiration peaks, which were enhanced by relatively thick modelled acrotelm (i.e. fast decomposing topsoil layer). Our results demonstrate that CH₄ parameterization has only a minor influence on modelled CH₄ fluxes, compared to WTL, but can nevertheless improve prediction accuracy, especially at sites characterized by high WTL.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6692 eISSN: eng

oai:publications.copernicus.org:egusphere148193 2026-11-12 egusphere

Czarnecki, Paulina Boucher, Olivier Bellouin, Nicolas 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6723 eISSN: eng

oai:publications.copernicus.org:egusphere147665 2026-11-12 egusphere

How, Penelope Petersen, Dorthe Kjeldsen, Kristian K. Raundrup, Katrine Dømgaard, Mads L. Carrivick, Jonathan L. Lea, James M. Messerli, Alexandra Rutishauser, Anja Fausto, Robert S. 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6331 eISSN: eng

oai:publications.copernicus.org:egusphere147685 2026-11-12 egusphere

Yasokaran, Oviga Rich, Jonathan E. Blanchet, Emma Patel, Janvi Wan, Congyi Heron, Philip J. 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6350 eISSN: eng

oai:publications.copernicus.org:egusphere147768 2026-11-12 egusphere

Deeb, Maha Dublet-Adli, Gabrielle Paltseva, Anna Lefort, Francois Jacquot, Aurore Egerer, Monika

This review examines how constructed soils can be integrated with phytoremediation approaches to overcome soil-related limitations and improve contaminant management at contaminated sites. We focus on contamination characteristics, soil design and amendments, engineering practices, biotic and abiotic site conditions, and plant selection strategies.

The reviewed literature demonstrates that appropriate soil engineering, including the use of constructed soils, can improve plant establishment, modify contaminant bioavailability and mobility, and enhance the performance of phytoremediation strategies. Overall, integrating soil engineering and constructed soils with phytoremediation represents a promising framework for contaminated-site management. By improving rooting conditions, enhancing contaminant accessibility or immobilization as required, and facilitating vegetation establishment, constructed soils can increase phytoremediation effectiveness and long-term sustainability. This integrated approach can also support ecosystem-service restoration, climate-change adaptation and mitigation, and the circular reuse of locally available surplus materials, although evidence on cost and long-term field performance remains limited.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6410 eISSN: eng

oai:publications.copernicus.org:egusphere146428 2026-11-12 egusphere

Keller, David P. Lenton, Andrew Scott, Vivian Vaughan, Naomi E. Ji, Duoying Jones, Chris D. Wiltshire, Andy Kravitz, Ben Muri, Helene Zickfeld, Kirsten Séférian, Roland Santana-Falcón, Yeray Köhler, Peter John, Jasmin G. Eliseev, Alexey V. Quilcaille, Yann Gasser, Thomas Shaffer, Gary Pedersen, Jens O. P. Ziehn, Tilo Kawamiya, Michio Yamamoto, Akitomo Koven, Charlie Burger, Friedrich A. Frölicher, Thomas L. Joos, Fortunat Jeltsch-Thömmes, Aurich Arora, Vivek Christian, James R. Tjiputra, Jerry Schwinger, Jörg Mengis, Nadine Monteiro, Estela A. 2 emission reductions are needed and it may be possible to use alongside carbon dioxide removal (CDR) methods to return atmospheric CO₂ concentrations to lower levels, with the assumption that lower CO₂ will rapidly lead to lower temperatures and reverse or limit other climate change impacts. Despite such assumption, a comprehensive understanding of the reversibility of the Earth system components is a persistent knowledge gap, which hinders our ability to assess future outcomes of decreasing anthropogenic forcing. Here we evaluate the reversibility of climate change through a multi-model analysis of how the Earth system and climate respond in the CMIP6 Carbon Dioxide Removal Model Intercomparison Project (CDRMIP) cdr-reversibility experiment. cdr-reversibility is an idealized CO₂ concentration peak and decline experiment where atmospheric CO₂ increases at 1% yr^-1from a pre-industrial level until 4 times its initial value, then decreases at 1% yr^-1 until pre-industrial levels are again reached, at which point CO₂ is held constant. A few modelled quantities reverse or overshoot initial levels, on the same timescale as the changes in CO₂ forcing, such as the land and ocean net primary productivity or the Atlantic Meridional Overturning Circulation – at least when viewed at the global annual mean level. However, when responding to decreasing CO₂ concentration many properties exhibit time lags and hysteresis, e.g. changes in ocean and land carbon stocks or sea level. While some variables respond to mainly one specific driver, most show a hysteresis behaviour relative to all the considered driving forcers, namely surface air temperature, atmospheric CO₂ or cumulative emissions. Due to such, the majority of the considered environmental variables would take long, many times longer than a human lifetime, to return to their unperturbed values (if this ever occurs). Therefore, exceeding and then reversing a climate target would have a clear legacy in the climate system even if CO₂ concentrations return to pre-industrial levels.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-5520 eISSN: eng

oai:publications.copernicus.org:egusphere146498 2026-11-12 egusphere

Meier, Thibault Pierre Ferrachat, Sylvaine Bouzdine, Iolène Caratsch, Andrina Enz, Bernhard Lohmann, Ulrike 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-5568 eISSN: eng

oai:publications.copernicus.org:egusphere147425 2026-11-12 egusphere

Deng, Shuaishuai Burkhardt, Jürgen Lauerwald, Ronny Flechard, Christophe Knauer, Jürgen Dumont, Benjamin Baud-Fraile, Emilio Su, Yang Yu, Ke Viovy, Nicolas Loubet, Benjamin 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6152 eISSN: eng

oai:publications.copernicus.org:egusphere147175 2026-11-12 egusphere

Iwantoro, Arya Harahap, Rima Boulton, Sarah Masselink, Gerd 2 reconstructed-event inundation above highest astronomical tide (HAT), high tide increases inundated area to 11.84 km², a 3.1-fold increase. These results support tide-informed hazard maps, evacuation planning, community education, and preparedness close to tsunami sources.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-5978 eISSN: eng

oai:publications.copernicus.org:egusphere147329 2026-11-12 egusphere

La, Inyeob Grabowski, Wojciech W. Shima, Shin-ichiro Yum, Seong Soo dQ_ice, the relative enhancement of domain-mean ice mixing ratio in EVAP compared with NOEVAP, and Δf_ice, the corresponding increase in ice mass fraction. With gravity, both metrics show a turnover with ascent rate under polluted, Seoul-like conditions: they increase from low to intermediate ascent rates as faster cooling reduces sedimentation losses, but decrease at higher ascent rates as mixed-phase residence time becomes too short for sustained depositional growth. Under lower soluble-aerosol concentrations, fewer, larger droplets sediment more efficiently, weakening the WBF response. Without gravity and particle loss, WBF decreases monotonically with ascent rate, indicating dominant residence-time control. These results highlight the importance of finite-depth particle losses when interpreting chamber-based WBF measurements.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-6098 eISSN: eng

oai:publications.copernicus.org:egusphere145935 2026-11-12 egusphere

He, Yanyi R_s) from reanalysis products is widely used to assess the reliability, stability, and intermittency of photovoltaic power generation and other applications, owing to their full spatiotemporal coverage and physical consistency. However, whether reanalyses faithfully represent the characteristics of extreme R_s remains insufficiently evaluated. To address this, we assessed the performance of two major reanalysis products, ERA5 and MERRA-2, in simulating mean and extreme R_s across China during 1961–2016 with the help of precious ground-based observations of daily R_s. Observational analysis of mean R_s shows pronounced solar dimming before 1994, followed by weak brightening. Extremely high R_s (R_s90p) frequency presents multidecadal variations broadly consistent with mean R_s, whereas its magnitude increases persistently from 1980 onward. Conversely, extremely low R_s (R_s10p) frequency increases steadily during 1961–2016, while its magnitude decreases until 1994 and then reverses thereafter. Although ERA5 broadly captures most segmented variations of both extremes, it underestimates by over 90 % the pre-1980 decline in R_s90p frequency and the post-1994 increases in the frequencies of both extremes. MERRA-2 performs worse than ERA5, particularly in failing to reproduce the evolution of R_s90p frequency and magnitude. The attribution analysis reveals that trend biases in R_s90p are predominantly controlled by those in clear-sky R_s in reanalysis products whereas cloud- and aerosol-related processes jointly influence trend biases in R_s10p. These findings highlight the limitations of current reanalyses in simulating extreme R_s and the need to interpret cautiously their long-term trends in climate and solar energy applications.]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-5275 eISSN: eng

oai:publications.copernicus.org:egusphere145739 2026-11-12 egusphere

Harteg, Jakob Jones, Colin Donges, Jonathan F. Abe, Manabu Cadule, Patricia Castruccio, Frederic Danabasoglu, Gokhan Fröb, Friederike Frölicher, Thomas L. Guo, Chuncheng Köhn, Eike Liddicoat, Spencer Romanou, Anastasia Silvy, Yona Torsvik, Tomas Wyser, Klaus Yokohata, Tokuta Ziehn, Tilo Winkelmann, Ricarda Loriani, Sina 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-5162 eISSN: eng

oai:publications.copernicus.org:egusphere146568 2026-11-12 egusphere

Liboriussen, Michael Skytte Hansen, Jesper Schmidt 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-5623 eISSN: eng

oai:publications.copernicus.org:egusphere146597 2026-11-12 egusphere

Phillips, Samuel B. Li, Xuyang 2026-11-12 Text application/pdf https://doi.org/10.5194/egusphere-2026-5646 eISSN: eng

oai:publications.copernicus.org:cp139850 2026-11-12 cp

Lin, Qiaoyun Xu, Chenxi Huang, Ru An, Wenling Matskovsky, Vladimir Solomina, Olga Dolgova, Ekaterina Zhao, Yaru Guo, Zhengtang Hydroclimate variability across the East European Plain plays a critical role in regional ecosystems and climate dynamics, yet moisture-sensitive tree-ring proxies remain scarce in this region, particularly at high latitudes where tree-ring width (TRW) and density are primarily controlled by temperature. Tree-ring cellulose oxygen isotopes (δ¹⁸O_TRC) have the potential to serve as a useful hydroclimate proxy, but their climatic signal in this region remains poorly understood. Here, we developed three δ¹⁸O_TRC chronologies of Scots pine (Pinus sylvestris L.) from the northern, central, and southern East European Plain to assess their climate signals. The δ¹⁸O_TRC chronologies from the three sites show similar responses to summer moisture conditions. The northern δ¹⁸O_TRC shows the strongest relationship with vapor pressure deficit (VPD), the central δ¹⁸O_TRC records both hydroclimate variability and precipitation oxygen isotopes (δ¹⁸O_p) signals, and the southern δ¹⁸O_TRC mainly reflects the Standardized Precipitation Evapotranspiration Index (SPEI). In contrast, TRW shows weak hydroclimate sensitivity at the northern and central sites, whereas at the southern site it mainly reflects soil moisture. Overall, compared with TRW, δ¹⁸O_TRC better captures regional summer hydroclimate signals, particularly capturing signals related to atmospheric drought.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/cp-22-2015-2026 eISSN: 1814-9332 eng

oai:publications.copernicus.org:bg139751 2026-11-12 bg

Friedrich, Tobias Hošeková, Lucia Powell, Brian S. The consequences of overlapping environmental stressors – referred to as compound events – may be more harmful to marine ecosystems than as individual stressors. Using recently conducted submesoscale-permitting future projections for the Main Hawaiian Islands, we present the first assessment of future compound events for Hawaiian waters. Our analysis focuses on surface and sub-surface heat-stress, ocean acidification, and low-oxygen events and is based on three different greenhouse gas emission scenarios. We show that a large fraction of ocean around Hawai'i will be subject to compound events in the near future. However, the projected event characteristics such as duration and intensity vary substantially across the region suggesting that potential ecosystem impacts may differ over short distances. Our results reveal that these spatial differences are mainly driven by considerably different magnitudes of natural variability in ocean physics and chemistry across the domain driven by mesoscale processes, while anthropogenic trends exhibit only minor spatial differences. Our analysis demonstrates that small-scale tidal variability can significantly mitigate compound events in near-shore regions, including some designated Marine Protected Areas. Overall, our findings highlight the need for high-resolution numerical models as well as for an extended observation network for robust future projections of local extreme events.

]]> 2026-11-12 Text application/pdf https://doi.org/10.5194/bg-23-8233-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg140424 2026-11-11 bg

Tetard, Martin Marchant, Ross Automated microscopy workflows, including image acquisition, processing, and recognition using artificial intelligence (AI), are getting a growing interest from the scientific community in biogeosciences, as more and more research institutes are actively working on building datasets of images to train artificial convolutional neural networks (CNNs) to identify microscopic objects.

Here, we present a new, affordable, AI-assisted, and open-source Raspberry Pi-powered camera that can fit any microscope equipped with a regular C-mount (or CS-mount) camera thread. This camera is the first fully self-contained camera equipped with an integrated Single-Board Computer (Raspberry Pi 5) and high-resolution camera sensor (12.3 mp), attached together using a 3D-printable adaptor. Using two new open-source workflows written using the Python language and freely downloadable too, the camera is capable of performing automated microscopy using either an automated image segmentation workflow (RaCAM_IS software, including image acquisition, automated image processing, and object recognition using trained ResNet50 CNN models) or an object detection workflow (RaCAM_OD software, including image acquisition and automated still image/live stream object detection using YOLO models).

The camera is also adapted to on-field tasks such as core description, biostratigraphy or even palaeoenvironmental reconstructions based on microfossils census data or morphometry, as it can operate without the need for a spare computer and run directly on a power bank. Finally, since the automated microscopy workflows rely on images directly captured by the camera, applications can also be extended outside of the microscopy and micropaleontology research fields as any picture acquired with this device can virtually be processed.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8079-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg140925 2026-11-11 bg

Irob, Katja Chang, Liling Preisler, Yakir Fiedler, Sebastian Büchner, Matthias Grünzweig, José M. Sheffer, Efrat Dryland forests represent a significant but uncertain component of the terrestrial carbon sink, where rising CO₂ and intensifying drought and heat stress exert opposing controls on carbon and water fluxes. Using ED2.2-hydraulics calibrated against 21 years of flux tower and inventory data from Yatir Forest, an arid pine plantation in Israel, we simulated carbon fluxes, biomass dynamics, and water-use efficiency under current climate and high-emission scenarios (SSP3-7.0, SSP5-8.5) through 2100 using five general circulation models.

CO₂ fertilization initially enhanced productivity and biomass accumulation despite periodic drought, with the strongest response under SSP3-7.0. Under SSP5-8.5, compound heat and drought stress suppressed productivity below SSP3-7.0 levels despite higher CO₂ concentrations, triggering stand collapse in two projections and eliminating approximately 40 % of accumulated biomass. Driver decomposition showed that forest responses shifted from CO₂-dominated to interaction-dominated by late century, with compound heat and drought stress explaining 39 %–66 % of the relative importance of all drivers by late century. Apparent biomass gains under severe scenarios reflected accumulation in fewer, larger surviving individuals as stand density declined, masking structural deterioration in aggregate metrics.

Functional decline (productivity, water-use efficiency) preceded structural changes by 7–37 years depending on scenario, providing an early warning window before visible deterioration. These results show that CO₂ fertilization benefits cannot compensate for the compound climate extremes that accompany high emissions, and that functional indicators must be monitored alongside structural metrics to detect forest vulnerability in dryland afforestation systems.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8097-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg139732 2026-11-11 bg

Gore, Catrina Mueller, Peter Chapman, Mark Molin, Franck Schmiedl, Gerhard Milker, Yvonne Benson, Lisa Marca, Alina Nolte, Stefanie Restoring saltmarshes to enhance atmospheric carbon dioxide uptake is thought to represent a means of climate change mitigation. While carbon stocks in restored marshes were found to reach equivalence with natural sites, the shares of autochthonous and allochthonous carbon sources entering these marshes are less well known. This issue is important because allochthonous carbon is usually excluded from stock calculations. To determine if differences do exist, the conventional tools for determining organic matter source – elemental, stable isotope and thermogravimetric analyses – were applied to sediments from four restored saltmarshes of different ages. Comparisons were then made with existing data from nearby natural marshes. Breach depth horizons in individual cores were successfully identified using foraminifera, unicellular marine protists. The

OC / N

-ratio was persistently lower in restored saltmarshes compared with natural counterparts even 100 years after the creation of a breach. Additionally, δ¹³C signals indicated a mixture of organic matter sources to the restored sites and there was often a higher proportion, based upon thermal sensitivity, of recalcitrant material in the organic matter of the restored marshes. Together, these results indicated that a higher proportion of allochthonous organic matter was entering these restored marshes. Understanding the composition of the organic matter in restored marsh sediment will allow the development of robust and constructive climate change mitigation methods.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8207-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg141531 2026-11-11 bg

Fay, Amanda R. Carroll, Dustin McKinley, Galen A. Lovenduski, Nicole S. Menemenlis, Dimitris Zhang, Hong The ocean plays a critical role in sequestering carbon, yet how the air–sea carbon sink will respond to rapid reductions in atmospheric carbon dioxide (CO₂) concentrations remains a key uncertainty for climate mitigation and carbon accounting. In this study, we utilize the ECCO-Darwin ocean biogeochemistry model to simulate the ocean's response to a range of near-term CO₂ mitigation scenarios which are simulated with reduced atmospheric carbon concentrations. Our results demonstrate an immediate but spatially heterogeneous weakening of the ocean carbon sink following reduced atmospheric forcing. Global air–sea carbon uptake decreases substantially within the first several years of mitigation, with the magnitude of the reduction scaling with the strength of the mitigation scenario. We find that the mitigation signal is primarily confined to the upper-500 m, reflecting dominant decadal-scale ventilation pathways. The most pronounced reductions in uptake occur in subtropical thermocline regions, western boundary currents, and the subpolar North Atlantic – regions characterized by intense ventilation and rapid air–sea equilibration. These findings align with recent CMIP-based long-term projections and observation-based inversions, confirming that the areas currently dominating anthropogenic carbon uptake are also the most sensitive to atmospheric forcing changes. Our results suggest that observational efforts to track impacts from reduced atmospheric carbon levels should be prioritized in these high-latitude and boundary current systems, where signals emerge earliest and most strongly. Ultimately, this study underscores the high sensitivity of the ocean carbon sink to changes in atmospheric forcing and highlights the necessity of sustained, strategically-placed observations to detect and attribute changes in the global carbon budget under future climate strategies.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8063-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg139997 2026-11-11 bg

Feldman, Andrew F. Smith, William K. Konings, Alexandra G. Baur, Martin J. Browne, Marvin Chaparro, David Devine, Charles Diehl, Jen L. Endsley, Arthur Jagdhuber, Thomas Larson, Kristine M. Mar Valle-Rodriguez, Coral Schellenberg, Konstantin Zotta, Ruxandra-Maria Serbin, Shawn P. Monitoring plant water stress and biomass is limited by labor intensive measurements techniques. Observing plant water conditions more broadly is now enabled by microwave remote sensing. Specifically, satellite-based vegetation optical depth (VOD) provides daily observations of vegetation water volume at tens of kilometers. While satellite VOD has been used for many applications, VOD validations have rarely been carried out. A new method has enabled direct measurements of in-situ VOD, from Global Navigation Satellite Systems (GNSS). However, GNSS measurements have yet to be applied to more globally dominant grasslands and shrublands. Here, we explore how satellite-based VOD from SMAP and AMSR-2 compares with field-based microwave observations from 272 GNSS-based interferometric reflectometry (GNSS-IR) sites across the Western US as a part of the Plate Boundary Observatory (PBO) H₂O network. These sensors measure a proxy for VOD, or normalized microwave reflectance index (NMRI), at a much finer scale of tens of meters. We find that satellite VOD is generally positively correlated with GNSS NMRI with correlations between 0.2 to 0.6 across sites. These correlations increase to 0.3 to 0.7 when evaluating sites in regions with more homogenous vegetation types, lower tree cover, and larger seasonal vegetation dynamics. The correlations are higher for X-band VOD, likely related to our findings that X-band VOD and NMRI are both more sensitive to seasonal vegetation variations than C-band and L-band VOD products. These findings suggest that satellite VOD is capturing field-based GNSS signals in dryland ecosystems, and therefore that these sensors are a critical resource for calibrating and validating satellite VOD at scale.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8159-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg137384 2026-11-05 bg

Kobayashi, Hidetaka Yokohata, Tokuta Yamamoto, Akitomo Hajima, Tomohiro Tatebe, Hiroaki Oka, Akira Rodgers, Keith B. Despite their profound consequences for the global carbon cycle, multi-centennial ocean biogeochemical responses to anthropogenic greenhouse gas forcing remain poorly constrained. Here we investigate long-term oceanic responses to atmospheric CO₂ forcing using the Model for Interdisciplinary Research on Climate, Earth System version 2 for Long-term simulations (MIROC-ES2L) Earth system model driven by extended Shared Socio-economic Pathway (SSP) scenarios through to the year 2500. Ocean–atmosphere pCO₂ disequilibrium exhibits strong scenario dependence. Under the low-emission scenario SSP1–2.6, oceanic CO₂ undersaturation gradually weakens and approaches near equilibrium by 2100. By contrast, under the high-emission scenario SSP5–8.5, rapid increase in atmospheric pCO₂ results in increasing undersaturation of CO₂ in the ocean over the 21st century. Thereafter, surface-ocean CO₂ supersaturation progressively expand into the equatorial and subtropical oceans between the mid–23rd and late 25th century. The Southern Ocean remains persistently undersaturated throughout the simulations, consistent with sustained influence from deep waters that are weakly affected by anthropogenic perturbations. Under SSP5–8.5, oceanic CO₂ uptake continues to increase until the late 21st century. Thereafter, it gradually weakens as surface-ocean pCO₂ approaches atmospheric levels, whereas the Southern Ocean remains a persistent carbon sink throughout the simulation. Across all scenarios, early oceanic pCO₂ changes are primarily driven by increases in dissolved inorganic carbon, whereas alkalinity becomes an increasingly important control from the mid–22nd century onward under SSP5–8.5. A progressive decline in the oceanic CO₂ buffering capacity, driven by cumulative CO₂ uptake, increases the sensitivity of surface-ocean pCO₂ to additional carbon uptake. The buffering capacity approaches its effective minimum levels by the late 22nd century. In parallel, enhanced upper-ocean stratification and a slowdown of the deep overturning circulation reduce the upward transport of high alkalinity waters to the surface. This results in a decline in surface-ocean alkalinity that further enhances the influence of alkalinity on surface-ocean pCO₂ during this period. Marine biological productivity and export vary significantly as a function of atmospheric CO₂ trajectory. It increases under low-emission scenarios but declines under sustained high-emission scenarios. The transition between the two behaviors occurs when

p {CO}_{2}^{atm}

reaches approximately 3 times the preindustrial level and is closely associated with the weakening of the Atlantic Meridional Overturning Circulation and the resulting nutrient redistribution. Thermal stress and nutrient limitation persist in regions such as the Arctic Ocean until the late 25th century even under SSP1–2.6, indicating a centennial-scale lagged response of marine ecosystems to atmospheric CO₂ forcing. In the surface ocean, marine ecosystem stress (integrating thermal and biogeochemical stressors) continues to intensify through the late 22nd century under SSP5–8.5, despite the stabilization of atmospheric pCO₂, highlighting the long memory and limited reversibility of oceanic ecosystem stress.

]]> 2026-11-05 Text application/pdf https://doi.org/10.5194/bg-23-7807-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg135884 2026-11-11 bg

Tang, Hui Launiainen, Samuli Vira, Julius Kulmala, Liisa Palosuo, Taru Aaltonen, Hermanni Nevalainen, Olli Fer, Istem Vekuri, Henriikka Nousu, Jari-Pekka Korkiakoski, Mika Liski, Jari Plant hydraulics play a critical role in coordinating photosynthesis, water use, and hydraulic safety when facing water scarcity. The hydraulic traits of boreal crops and their relevance to productivity and drought resistance, however, remain poorly researched. In this study, we combined multi-year carbon and water flux measurements from two Finnish fields representing contrasting boreal cropping systems – a perennial forage grass mixture and an annual cereal crop (oats) – with a novel modelling framework coupling plant photosynthesis, hydraulics, and soil moisture dynamics to decipher the field-level effective hydraulic traits (i.e., apparent hydraulic traits) of the crops and their association with crop performance under varying drought conditions. The model reproduced the observed carbon and water fluxes well and revealed relatively low maximum whole-plant hydraulic conductance and conservative water-use strategies in both crops. Under drought, low hydraulic efficiency prevented soil water depletion and thereby supported high productivity through drought avoidance, whereas its advantage diminished under wetter conditions. Both crops were substantially more susceptible to atmospheric dryness than to low soil moisture, highlighting vapor pressure deficit as an important constraint on crop productivity under boreal conditions. The remaining discrepancy between the model-inferred apparent hydraulic traits and available empirical measurements for temperate crops indicates the need for more direct hydraulic measurements of boreal crops. Our findings further underscore the importance of incorporating crop hydraulic processes in process-based crop models to gain physiological insights into crop performance and to enhance their accuracy and predictive power under current and future climates.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8183-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:ard148281 2026-11-11 ard

Akl, Clara Schobing, Julie Schönnenbeck, Cornelius Trouvé, Gwenaëlle 2026-11-11 Text application/pdf https://doi.org/10.5194/ar-2026-47 eISSN: 2940-3391 eng

oai:publications.copernicus.org:bg141973 2026-11-11 bg

Chintala, Syam Jarlan, Lionel Rivalland, Vincent Boone, Aaron Dare-Idowu, Oluwakemi Dantec, Valerie Boulet, Gilles Kambhammettu, BVNP Brut, Aurore Water use efficiency (WUE) links carbon assimilation and water loss and is an important indicator of ecosystem functioning under changing hydroclimatic conditions. Process-based land surface models (LSMs) provide a framework for simulating carbon-water interactions, but their ability to reproduce ecosystem-scale WUE across contrasting climates remains insufficiently evaluated. This study assesses the performance of the ISBA-A-g_s land surface model, implemented within the SURFEX platform, in simulating gross primary productivity (GPP), evapotranspiration (ET), and WUE (GPP

/

ET) for maize under temperate conditions in France (FR-Lam) and tropical semi-arid conditions in India (Ind-IITH). The model was driven by site-specific meteorological and vegetation data across six growing seasons at FR-Lam under sprinkler irrigation and two growing seasons at Ind-IITH, representing monsoon and winter crops under alternate furrow irrigation (AFI). Model calibration indicated contrasting controls on carbon and water exchanges between the two sites. At FR-Lam, relatively higher cuticular conductance and stronger atmospheric control on stomatal behaviour were identified, whereas at Ind-IITH, mesophyll conductance and soil moisture stress thresholds were important calibration parameters. At FR-Lam, the model simulated mean seasonal cumulative GPP, ET, and WUE of 1039±20 g C m⁻², 610±31 kg H₂O m⁻², and 1.70±0.10 g C kg⁻¹ H₂O, respectively, compared with measured values of 1026±30 g C m⁻², 562±42 kg H₂O m⁻², and 1.82±0.11 g C kg⁻¹ H₂O. At Ind-IITH, simulated values were 766±15 g C m⁻², 567±30 kg H₂O m⁻², and 1.35±0.11 g C kg⁻¹ H₂O, compared with measured values of 793±11 g C m⁻², 522±20 kg H₂O m⁻², and 1.51±0.12 g C kg⁻¹ H₂O. Diagnostic analysis based on underlying water use efficiency (uWUE) further indicated that the model reproduced the relationship between carbon assimilation and transpiration-driven water loss. Overall, ISBA-A-g_s captured the seasonal dynamics of maize carbon and water exchanges across the two contrasting climates, although differences between simulated and measured ET and WUE remained. The results highlight the potential of process-based modelling to assess carbon-water coupling across diverse hydroclimatic conditions and provide insights into the physiological controls governing crop water use.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8137-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:bg142810 2026-11-11 bg

Jones, Rhiannon L. Lohan, Maeve C. Ehmen, Tobias Friberg, Lisa Lincoln, Ben Sheen, Katy Foden, Siobhán Landeghem, Katrien Retallick, Kate Dadd, George Scourse, James Annett, Amber L. Southern Ocean primary productivity is often limited by the availability of the essential micronutrient iron (Fe), and sediment-derived fluxes of Fe from the Antarctic shelf have been linked with hotspots of productivity. Glacial meltwater along the West Antarctic Peninsula delivers significant volumes of Fe-rich glacially weathered material to shelf surface sediments. Measured acoustic doppler current profiler and acoustic backscatter turbidity data indicate ongoing resuspension of sediment in the coastal region. Onboard mesocosm experiments simulated resuspension of oxic sediments, rich in highly reactive Fe (2–9 mg g⁻¹), in the nearshore glaciated West Antarctic Peninsula across King George Island, Anvers Island, and Adelaide Island. These experiments produced a high sustained bottom water enrichment in dissolved Fe of ∼ 4–12 nM over the 48 h experiment duration.

Our observations support a dissolved Fe flux to the water column of 0.18–4.0 µmol m⁻² d⁻¹ by resuspension within the glaciated fjords, demonstrating that resuspension of reactive oxic nearshore sediments is a key source of dissolved and reactive particulate Fe to Antarctic shelf waters, the export of which could potentially supply bioavailable Fe to Fe-limited Southern Ocean waters.

]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/bg-23-8117-2026 eISSN: 1726-4189 eng

oai:publications.copernicus.org:egusphere146684 2026-11-11 egusphere

Shan, Yufeng Qian, Peng Yang, Kun Wei, Jiangfeng Qiu, Dongdong Liu, Fangyu Ge, Jun 2026-11-11 Text application/pdf https://doi.org/10.5194/egusphere-2026-5716 eISSN: eng

oai:publications.copernicus.org:egusphere146645 2026-11-11 egusphere

Dong, Wen Wang, Xingbao Xu, Kai Zhou, Hanxing Huang, Yincheng Lou, Zhi Zhang, Yue Huang, Zhenyang Zhang, Jing Shao, Junjiong Du, Yuanyuan Jin, Xiaoai Chen, Jian Ren, Yuan 3) hotspots where intense precursor emissions and high population densities escalate human exposure risks. Current deposition models typically rely on coarse land-use classifications, failing to capture the species-level heterogeneity at the city scale. We quantified O₃ dry deposition across 20 common tree species in a subtropical megacity using a modified micrometeorological gradient method to derive species-resolved resistance parameters. Field measurements identified substantial interspecific variation: daytime canopy concentration gradients peaked at 10.02 ± 0.86 ppb (Platanus acerifolia). While standardized stomatal conductance correlates with the inverted minimum stomatal resistance (1/R_{s, min}, R² = 0.36, P < 0.001), this relationship provides partial physiological support for the inferred resistance parameters. Sensitivity analysis showed that model-estimated deposition velocity was most sensitive to LAI, followed by wind speed and roughness length. Notably, a 20 % LAI increase reduced estimated deposition velocity by 17.55 % under the prescribed sensitivity experiments. These findings highlight species-level differences in O₃ deposition and the coupled roles of canopy structure, aerodynamic transport, and physiological regulation. The resulting resistance estimates provide observational constraints for species-resolved parameterization in atmospheric deposition models, although their transferability requires further validation.]]> 2026-11-11 Text application/pdf https://doi.org/10.5194/egusphere-2026-5685 eISSN: eng 54498690