Journal of Advances in Modeling Earth Systems最新文献

{"title":"A Model for Regional-Scale Water Erosion and Sediment Transport and Its Application to the Yellow River Basin","authors":"Cong Jiang,&nbsp;Eric J. R. Parteli,&nbsp;Yaping Shao","doi":"10.1029/2024MS004593","DOIUrl":"https://doi.org/10.1029/2024MS004593","url":null,"abstract":"<p>On catchment scales, sediment discharge depends on both sediment transport capacity and sediment availability. The quantification of sediment discharge at the regional scales is important but is rarely adequately represented in regional hydrological models. Here, we introduce a regional water erosion and sediment transport model, Atmospheric and Hydrological-Sediment Modeling System (AHMS-SED). This model integrates the Atmospheric and Hydrological Modeling System (AHMS) with the improved CASCade 2-Dimensional SEDiment (CASC2D-SED) model and incorporates gully erosion as a significant factor affecting sediment supply. A gully area index is introduced to quantify the fraction of the gully area and the enhancement of water erosion induced by concentrated flow in gullies. We use the AHMS-SED to simulate the sediment processes in the Yellow River Basin from 1979 to 1987 at a 20 km resolution. We find quantitative agreement between the observations and model predictions for monthly sediment fluxes at five major hydrological stations along the Yellow River, with excellent performance metrics (modified Kling-Gupta efficiency = 0.90, Nash–Sutcliffe model efficiency coefficient = 0.81) at the basin outlet. The results demonstrate the strong performance of the AHMS-SED and the robustness of the sediment supply estimates. We also use AHMS-SED to investigate how changes in climate and human activities affect sediment discharge in the Yellow River. The model shows that halving precipitation intensity substantially reduces sediment discharge, halving precipitation amount reduces it by 60%, and doubling irrigation reduces it by 10%.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 5","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ROSSMIX 2.0: A Simplified Meso-Scale Eddy Closure Applied to a Realistic Ocean Model","authors":"Carsten Eden,&nbsp;Jan Dettmer","doi":"10.1029/2024MS004769","DOIUrl":"https://doi.org/10.1029/2024MS004769","url":null,"abstract":"<p>A new closure, ROSSMIX 2.0, for the effect of meso-scale eddies in non-eddy-resolving ocean models is presented and evaluated. It combines aspects of several previous closures in a simplified approach: local linear stability analysis is used to predict the vertical and lateral shape of eddy correlations, while a wave energy equation co-integrated in the ocean model predicts their amplitudes. The new closure is implemented and evaluated with good success in an idealized channel model of vertical and lateral shear instability, and in a realistic quasi-global ocean model. The new closure enhances the meridional overturning circulation both globally and in the individual basins, with clearer connection of the large-scale overturning cells in the Southern Ocean. This comes along with enhanced northward heat transport and horizontal transports in better agreement with observations, and a reduced bias in watermasses.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 5","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004769","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Two Stream Radiative Transfer Model for Vertically Inhomogeneous Vegetation Canopies Including Internal Emission","authors":"T. L. Quaife","doi":"10.1029/2024MS004712","DOIUrl":"https://doi.org/10.1029/2024MS004712","url":null,"abstract":"<p>Two stream models of radiative transfer are used in the land surface schemes of climate and Earth system models to represent the interaction of solar and terrestrial radiation with vegetation canopies. This is done both to model the surface energy balance and the photosynthetic flux of carbon into the terrestrial biosphere. Two stream models are especially attractive for inclusion in large complex models of the Earth as they allow for an analytical and computationally cheap solution to the radiative transfer problem, whilst accounting for all orders of photon scattering and hence preserving energy balance. As the vegetation processes described in land surface models become more complex, new two stream formulations are required to correctly represent radiative components. For example, as ecosystem demography becomes more prevalent in land models, the need to represent canopies with vertically varying structure becomes more important, but an analytical, efficient solution to the transfer problem is still desirable. Here we describe a two stream scheme constructed from layers with independent optical properties. It is physically consistent with the existing radiative transfer schemes in many current land surface models, with typical differences in the order of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <msup>\u0000 <mn>0</mn>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>14</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $1{0}^{-14}$</annotation>\u0000 </semantics></math> in normalized flux units, and its solution is analytical. The model can be used to represent complex canopy structures and its formulation lends itself to modeling the canopy leaving flux arising from internal emissions, for example, longwave radiation or fluorescence. We also discuss the parameterization of two stream schemes and demonstrate that this could be improved in existing models.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 5","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004712","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced Convective Microphysics Scheme and Its Impacts on Mean Climate in E3SM","authors":"Xiaoliang Song,&nbsp;Guang J. Zhang,&nbsp;Chris Terai,&nbsp;Shaocheng Xie","doi":"10.1029/2024MS004656","DOIUrl":"https://doi.org/10.1029/2024MS004656","url":null,"abstract":"<p>To improve the representation of microphysical processes in convective clouds and their interaction with aerosol and stratiform clouds, a two-moment convective microphysics parameterization (CMP) scheme developed by Song and Zhang (2011, https://doi.org/10.1029/2010jd014833) is upgraded and implemented in E3SM. The new developments include: (a) implementing a parameterization for graupel to enhance the representation of ice-phase microphysical processes; (b) representing the impact of spatial inhomogeneity of cloud droplets in cumulus ensembles on autoconversion and accretion processes to improve the representation of warm-rain microphysical processes; (c) implementing a comprehensive Bergeron process parameterization to better represent mixed-phase microphysical processes; and (d) representing the interactions between ice-phase microphysics and cloud thermodynamics. Simulations show that the cloud microphysical properties simulated by the CMP are generally in good agreement with observations. It reasonably simulates the changes in droplets effective radius related to precipitation formation in convective clouds, as identified from satellite observations. It also successfully simulates the contrast in these processes between maritime and continental clouds, demonstrating its capability to simulate the impact of aerosols on convection. Analyses of the impact of CMP on climate mean state simulation demonstrate that the CMP slightly improves the simulations of precipitation, cloud macrophysical properties, longwave cloud radiative forcing, zonal wind, and temperature. However, a degradation in shortwave cloud radiative forcing occurs.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 5","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004656","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Photosynthesis Acclimates to Rising Temperatures Through Predictable Changes in Photosynthetic Capacities, Enzyme Kinetics, and Stomatal Sensitivity","authors":"Pascal D. Schneider,&nbsp;Arthur Gessler,&nbsp;Benjamin D. Stocker","doi":"10.1029/2024MS004789","DOIUrl":"https://doi.org/10.1029/2024MS004789","url":null,"abstract":"&lt;p&gt;Thermal acclimation of photosynthesis, the physiological adjustment to temperature over weeks, may help plants mitigate adverse impacts of global warming, but is often under-represented in Earth System Models (ESMs). We evaluated a plant functional type (PFT)-agnostic, optimality-based model of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;C&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{C}}_{3}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; photosynthesis with a global data set of leaf gas exchange measurements. We investigated how three key photosynthesis traits vary along a gradient of growing-season temperatures &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mtext&gt;growth&lt;/mtext&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({T}_{text{growth}}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;: optimal photosynthesis temperature &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mtext&gt;opt&lt;/mtext&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({T}_{text{opt}}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, net photosynthesis rate at &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mtext&gt;opt&lt;/mtext&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${T}_{text{opt}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;mtext&gt;opt&lt;/mtext&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({A}_{text{opt}}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and the width of the temperature response curve &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mtext&gt;span&lt;/mtext&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({T}_{text{span}}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. We analyzed how each trait is influenced by three acclimation processes: acclimation ","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004789","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing Challenges in Simulating Inter–Annual Variability of Gross Primary Production","authors":"Ranit De,&nbsp;Shanning Bao,&nbsp;Sujan Koirala,&nbsp;Alexander Brenning,&nbsp;Markus Reichstein,&nbsp;Torbern Tagesson,&nbsp;Michael Liddell,&nbsp;Andreas Ibrom,&nbsp;Sebastian Wolf,&nbsp;Ladislav Šigut,&nbsp;Lukas Hörtnagl,&nbsp;William Woodgate,&nbsp;Mika Korkiakoski,&nbsp;Lutz Merbold,&nbsp;T. Andrew Black,&nbsp;Marilyn Roland,&nbsp;Anne Klosterhalfen,&nbsp;Peter D. Blanken,&nbsp;Sara Knox,&nbsp;Simone Sabbatini,&nbsp;Bert Gielen,&nbsp;Leonardo Montagnani,&nbsp;Rasmus Fensholt,&nbsp;Georg Wohlfahrt,&nbsp;Ankur R. Desai,&nbsp;Eugénie Paul-Limoges,&nbsp;Marta Galvagno,&nbsp;Albin Hammerle,&nbsp;Georg Jocher,&nbsp;Borja Ruiz Reverter,&nbsp;David Holl,&nbsp;Jiquan Chen,&nbsp;Luca Vitale,&nbsp;M. Altaf Arain,&nbsp;Nuno Carvalhais","doi":"10.1029/2024MS004697","DOIUrl":"https://doi.org/10.1029/2024MS004697","url":null,"abstract":"<p>A long-standing challenge in studying the global carbon cycle has been understanding the factors controlling inter–annual variation (IAV) of carbon fluxes, and improving their representations in existing biogeochemical models. Here, we compared an optimality-based model and a semi-empirical light use efficiency model to understand how current models can be improved to simulate IAV of gross primary production (GPP). Both models simulated hourly GPP and were parameterized for (a) each site–year, (b) each site with an additional constraint on IAV (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>C</mi>\u0000 <mi>o</mi>\u0000 <mi>s</mi>\u0000 <msup>\u0000 <mi>t</mi>\u0000 <mi>IAV</mi>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $Cos{t}^{mathit{IAV}}$</annotation>\u0000 </semantics></math>), (c) each site, (d) each plant–functional type, and (e) globally. This was followed by forward runs using calibrated parameters, and model evaluations using Nash–Sutcliffe efficiency (NSE) as a model-fitness measure at different temporal scales across 198 eddy-covariance sites representing diverse climate–vegetation types. Both models simulated hourly GPP better (median normalized NSE: 0.83 and 0.85) than annual GPP (median normalized NSE: 0.54 and 0.63) for most sites. Specifically, the optimality-based model substantially improved from NSE of −1.39 to 0.92 when drought stress was explicitly included. Most of the variability in model performances was due to model types and parameterization strategies. The semi-empirical model produced statistically better hourly simulations than the optimality-based model, and site–year parameterization yielded better annual model performance. Annual model performance did not improve even when parameterized using <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>C</mi>\u0000 <mi>o</mi>\u0000 <mi>s</mi>\u0000 <msup>\u0000 <mi>t</mi>\u0000 <mi>IAV</mi>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $Cos{t}^{mathit{IAV}}$</annotation>\u0000 </semantics></math>. Furthermore, both models underestimated the peaks of diurnal GPP, suggesting that improving predictions of peaks could produce better annual model performance. Our findings reveal current modeling deficiencies in representing IAV of carbon fluxes and guide improvements in further model development.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 5","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004697","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving Solar Radiation Forecasts During Stratocumulus Conditions Using Large Eddy Simulations and an Ensemble Kalman Filter","authors":"Marleen P. van Soest,&nbsp;Stephan R. de Roode,&nbsp;Remco A. Verzijlbergh,&nbsp;Femke C. Vossepoel,&nbsp;Harm J. J. Jonker","doi":"10.1029/2024MS004759","DOIUrl":"https://doi.org/10.1029/2024MS004759","url":null,"abstract":"<p>Forecasting solar radiation is critical for balancing the electricity grid due to increasing production from solar energy. To this end, we need precise simulation of clouds, which is traditionally done by numerical weather prediction. However, these large-scale (LS) models struggle especially with forecasting stratocumulus clouds because their coarse vertical resolution cannot capture the sharp inversion present at stratocumulus cloud top. To address this issue, we employ large eddy simulation (LES), which operates at high resolution and has demonstrated superior accuracy in simulating stratocumulus clouds. However, LES relies on input data from a LS model, which is imperfect. To reduce the uncertainty caused by the LS data, we integrate a single ensemble Kalman filter step at the start of simulation in the LES model, utilizing local observations. Our results show that this approach is computationally feasible, robust, and reduces prediction error at assimilation by 50%. The improvement diminishes after approximately 1 hour of simulation due to the influence of large-scale forcing. Future work will focus on enhancing the LS inflow through nested simulations with realistic lateral boundary conditions to sustain the improvements in forecasting accuracy.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004759","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bayesian Source Identification With Dual Hierarchical Neural Networks for Urban Air Pollution","authors":"Elissar Al Aawar,&nbsp;Sofien Resifi,&nbsp;Hatem Jebari,&nbsp;Ibrahim Hoteit","doi":"10.1029/2024MS004790","DOIUrl":"https://doi.org/10.1029/2024MS004790","url":null,"abstract":"<p>Identifying urban air pollution sources is essential for public health and environmental sustainability. In this study, we propose a novel hierarchical method for urban air pollution source identification, leveraging deep learning (DL) within an efficient Bayesian inference framework. We rely on observations in the form of two-dimensional (2D) pollutant concentration distributions, and adopt the Wasserstein <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <msub>\u0000 <mi>W</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation> $left({W}_{2}right)$</annotation>\u0000 </semantics></math> distance to model the likelihood probability distribution. The hierarchical nature of the framework stems from the integration of two neural networks (NNs). The first one acts as an emulator that replicates the physical dispersion model to predict future pollution observations recursively over a defined timeframe. These predictions are then used as inputs for the second NN that approximates the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>W</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${W}_{2}$</annotation>\u0000 </semantics></math> distance between predicted and observed pollutant concentration distributions to rapidly compute the likelihood probability. The approach adopts a multi-model strategy to mitigate the accumulation of errors, particularly those arising from the recursive prediction steps across multiple time intervals, ensuring the reliability of predictions over extended periods. The proposed framework is implemented on graphics processing units (GPUs), enabling scalable computations for real-world applications and rapid decision making. Through extensive numerical experiments, we demonstrate the suggested method's effectiveness in accurately estimating pollution source parameters, including location, emission rate, and duration, using synthetic observational data. Sensitivity analyses further explore the impact of observational horizons and sampling on solution convergence and accuracy. Numerical results demonstrate robust performances and computational efficiency compared to the conventional approach, particularly in scenarios with limited computational resources and observations availability.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004790","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling Thermal and Biogeochemical Dynamics in Two Ponds Within Alaska's Yukon–Kuskokwim Delta: Impacts of Climatic Variability on Greenhouse Gas Fluxes","authors":"A. L. Mullen,&nbsp;E. E. Jafarov,&nbsp;J. K. Y. Hung,&nbsp;K. Gurbanov,&nbsp;V. Stepanenko,&nbsp;B. M. Rogers,&nbsp;J. D. Watts,&nbsp;S. M. Natali,&nbsp;B. A. Poulin","doi":"10.1029/2024MS004441","DOIUrl":"https://doi.org/10.1029/2024MS004441","url":null,"abstract":"<p>Fluxes of carbon dioxide (CO₂) and methane (CH₄) from open water bodies are critical components of carbon-climate feedbacks in high latitudes. Processes governing the spatial and temporal variability of these aquatic greenhouse gas (GHG) fluxes are still highly uncertain due to limited observational data sets and lack of modeling studies incorporating comprehensive thermal and biochemical processes. This research investigates how slight variations in climate propagate through the biogeochemical cycles of ponds and resulting impacts on GHG emissions. We examine the thermal and biogeochemical dynamics of two ponds in the Yukon–Kuskokwim Delta, Alaska, under varying climatic conditions to study the impacts on CO₂, CH₄, and oxygen (O₂) concentrations and fluxes. We performed multiple numerical experiments, using the LAKE process-based model and field measurements, to analyze how these ponds respond to variations in air temperature, shortwave radiation, and snow cover. Our study demonstrates that ice cover duration and water temperature are primary climatic drivers of GHG fluxes. Climate experiments led to reductions in ice cover duration and increased water temperatures, which subsequently enhanced CH₄ and CO₂ gas emissions from two study ponds. On average, cumulative CH₄ and CO₂ emissions were 5% and 10% higher, respectively, under increases in air temperature and shortwave radiation. Additionally, we uncovered a need to incorporate groundwater influxes of dissolved gases and nutrients in order to fully represent processes governing aquatic biochemical activity. Our work highlights the importance of understanding local-scale processes in predicting future Arctic contributions to GHG emissions.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004441","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Unified Framework to Reconcile Different Approaches of Modeling Transpiration Response to Water Stress: Plant Hydraulics, Supply Demand Balance, and Empirical Soil Water Stress Function","authors":"Yi Yang,&nbsp;Kaiyu Guan,&nbsp;Bin Peng,&nbsp;Xue Feng,&nbsp;Xiangtao Xu,&nbsp;Ming Pan,&nbsp;Brandon P. Sloan,&nbsp;Jingwen Zhang,&nbsp;Wang Zhou,&nbsp;Lingcheng Li,&nbsp;Murugesu Sivapalan,&nbsp;Elizabeth A. Ainsworth,&nbsp;Kimberly A. Novick,&nbsp;Zong-Liang Yang,&nbsp;Sheng Wang","doi":"10.1029/2023MS003911","DOIUrl":"https://doi.org/10.1029/2023MS003911","url":null,"abstract":"<p>Plant responses to water stress is a major uncertainty to predicting terrestrial ecosystem sensitivity to drought. Different approaches have been developed to represent plant water stress. Empirical approaches (the empirical soil water stress (or Beta) function and the supply-demand balance scheme) have been widely used for many decades; more mechanistic based approaches, that is, plant hydraulic models (PHMs), were increasingly adopted in the past decade. However, the relationships between them—and their underlying connections to physical processes—are not sufficiently understood. This limited understanding hinders informed decisions on the necessary complexities needed for different applications, with empirical approaches being mechanistically insufficient, and PHMs often being too complex to constrain. Here we introduce a unified framework for modeling transpiration responses to water stress, within which we demonstrate that empirical approaches are special cases of the full PHM, when the plant hydraulic parameters satisfy certain conditions. We further evaluate their response differences and identify the associated physical processes. Finally, we propose a methodology for assessing the necessity of added complexities of the PHM under various climatic conditions and ecosystem types, with case studies in three typical ecosystems: a humid Midwestern cropland, a semi-arid evergreen needleleaf forest, and an arid grassland. Notably, Beta function overestimates transpiration when VPD is high due to its lack of constraints from hydraulic transport and is therefore insufficient in high VPD environments. With the unified framework, we envision researchers can better understand the mechanistic bases of and the relationships between different approaches and make more informed choices.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":"17 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS003911","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}