Journal of Advances in Modeling Earth Systems最新文献

{"title":"Evaluation of an In-Canopy Wind and Wind Adjustment Factor Model for Wildfire Spread Applications Across Scales","authors":"Wei-Ting Hung,&nbsp;Patrick C. Campbell,&nbsp;Zachary Moon,&nbsp;Rick Saylor,&nbsp;John Kochendorfer,&nbsp;Temple R. Lee,&nbsp;William Massman","doi":"10.1029/2024MS004300","DOIUrl":"https://doi.org/10.1029/2024MS004300","url":null,"abstract":"<p>The representation of vegetative sub-canopy wind is critical in numerical weather prediction (NWP) models for the determination of the air-surface exchange processes of heat, momentum, and trace gases. Because of the relationship between wind speed and fire behaviors, the influence of the canopy on near-surface wind speed is critical for prognostic fire spread models used in regional NWP models. In practice, the wind speed at the midflame point of fires (midflame wind speed) is used to determine the rate of fire spread. However, the wind speeds from most in situ measurements and NWP models are taken at some reference height above the canopy and fire flames. Hence, this study develops a modular and computationally-efficient one-dimensional model set composed of a canopy wind model and a wind adjustment factor (WAF) model for NWP applications across scales. The model set uses prescribed foliage shape functions to represent the vertical vegetation profile and its impacts on the three-dimensional structure of horizontal wind speeds. Results from the canopy wind model well agree with ground-based observations with average mean absolute bias, root mean square error and determination coefficients around 0.18 m s⁻¹, 0.40 m s⁻¹and 0.90, respectively. The WAF model provides midflame wind speeds by estimating the WAF based on canopy, fire and flame characteristics. Various user-definable options provide flexibility to adapt to variations in canopy characteristics and additional complexities associated with wildfires. The model set is expected to improve NWP models by providing an improved representation of the sub-grid wind flows at any spatial scale.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024MS004300","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141537007","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":"Effect of Uncertainty in Water Vapor Continuum Absorption on CO2 Forcing, Longwave Feedback, and Climate Sensitivity","authors":"Florian E. Roemer,&nbsp;Stefan A. Buehler,&nbsp;Lukas Kluft,&nbsp;Robert Pincus","doi":"10.1029/2023MS004157","DOIUrl":"https://doi.org/10.1029/2023MS004157","url":null,"abstract":"<p>We investigate the effect of uncertainty in water vapor continuum absorption at terrestrial wavenumbers on CO₂ forcing <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>F</mi>\u0000 </mrow>\u0000 <annotation> $mathcal{F}$</annotation>\u0000 </semantics></math>, longwave feedback <i>λ</i>, and climate sensitivity <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>S</mi>\u0000 </mrow>\u0000 <annotation> $mathcal{S}$</annotation>\u0000 </semantics></math> at surface temperatures <i>T</i>_s between 270 and 330 K. We calculate this uncertainty using a line-by-line radiative-transfer model and a single-column atmospheric model, assuming a moist-adiabatic temperature lapse-rate and 80% relative humidity in the troposphere, an isothermal stratosphere, and clear skies. Due to the lack of a comprehensive model of continuum uncertainty, we represent continuum uncertainty in two different idealized approaches: In the first, we assume that the total continuum absorption is constrained at reference conditions; in the second, we assume that the total continuum absorption is constrained for all atmospheres in our model. In both approaches, we decrease the self continuum by 10% and adjust the foreign continuum accordingly. We find that continuum uncertainty mainly affects <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>S</mi>\u0000 </mrow>\u0000 <annotation> $mathcal{S}$</annotation>\u0000 </semantics></math> through its effect on <i>λ</i>. In the first approach, continuum uncertainty mainly affects <i>λ</i> through a decrease in the total continuum absorption with <i>T</i>_s; in the second approach, continuum uncertainty affects <i>λ</i> through a vertical redistribution of continuum absorption. In both experiments, the effect of continuum uncertainty on <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>S</mi>\u0000 </mrow>\u0000 <annotation> $mathcal{S}$</annotation>\u0000 </semantics></math> is modest at <i>T</i>_s = 288 K (≈0.02 K) but substantial at <i>T</i>_s ≥ 300 K (up to 0.2 K), because at high <i>T</i>_s, the effects of decreasing the self continuum and increasing the foreign continuum have the same sign. These results highlight the importance of a correct partitioning between self and foreign continuum to accurately determine the temperature dependence of Earth's climate sensitivity.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS004157","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536919","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":"Learning Closed-Form Equations for Subgrid-Scale Closures From High-Fidelity Data: Promises and Challenges","authors":"Karan Jakhar,&nbsp;Yifei Guan,&nbsp;Rambod Mojgani,&nbsp;Ashesh Chattopadhyay,&nbsp;Pedram Hassanzadeh","doi":"10.1029/2023MS003874","DOIUrl":"https://doi.org/10.1029/2023MS003874","url":null,"abstract":"<p>There is growing interest in discovering interpretable, closed-form equations for subgrid-scale (SGS) closures/parameterizations of complex processes in Earth systems. Here, we apply a common equation-discovery technique with expansive libraries to learn closures from filtered direct numerical simulations of 2D turbulence and Rayleigh-Bénard convection (RBC). Across common filters (e.g., Gaussian, box), we robustly discover closures of the same form for momentum and heat fluxes. These closures depend on nonlinear combinations of gradients of filtered variables, with constants that are independent of the fluid/flow properties and only depend on filter type/size. We show that these closures are the nonlinear gradient model (NGM), which is derivable analytically using Taylor-series. Indeed, we suggest that with common (physics-free) equation-discovery algorithms, for many common systems/physics, discovered closures are consistent with the leading term of the Taylor-series (except when cutoff filters are used). Like previous studies, we find that large-eddy simulations with NGM closures are unstable, despite significant similarities between the true and NGM-predicted fluxes (correlations &gt;0.95). We identify two shortcomings as reasons for these instabilities: in 2D, NGM produces zero kinetic energy transfer between resolved and subgrid scales, lacking both diffusion and backscattering. In RBC, potential energy backscattering is poorly predicted. Moreover, we show that SGS fluxes diagnosed from data, presumed the “truth” for discovery, depend on filtering procedures and are not unique. Accordingly, to learn accurate, stable closures in future work, we propose several ideas around using physics-informed libraries, loss functions, and metrics. These findings are relevant to closure modeling of any multi-scale system.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS003874","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536550","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":"Bulk Microphysics Schemes May Perform Better With a Unified Cloud-Rain Category","authors":"Arthur Z. Hu,&nbsp;Adele L. Igel","doi":"10.1029/2023MS004068","DOIUrl":"https://doi.org/10.1029/2023MS004068","url":null,"abstract":"<p>Bulk microphysics schemes continue to face challenges due in part to the necessary simplification of hydrometeor properties and processes that is inherent to any parameterization. In all operational bulk schemes, one such simplification is the division of liquid water into two subcategories (cloud and rain) when predicting the evolution of warm clouds. It was previously found that biases in collisional growth in a bulk scheme with these separate liquid water categories can be mitigated with a unified liquid water category in which cloud and rain are contained within the same category. In this study, we examine the effect of artificially separating the liquid water category on other microphysical processes and in more realistic settings. Both our idealized 1D and 3D results show that a unified category bulk scheme is fundamentally better at predicting the timing and intensity of rain from warm-phase cumulus clouds compared to a traditional (separate) category bulk scheme. This is because a unified category bulk scheme allows a bimodal distribution to exist within one traditional “rain” category, whereas separate category bulk scheme only have one mode per category. This advantage allows the unified bulk scheme to retain the information of the largest droplets even as they fall through a layer of small raindrops. A separate category bulk scheme fails to represent this bimodal feature in comparison.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS004068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488533","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":"Evaluating Numerical Methods to Investigate Spectral Solar Radiative Transfer in Plant Canopies","authors":"Zachary Moon,&nbsp;Jose D. Fuentes","doi":"10.1029/2023MS004136","DOIUrl":"https://doi.org/10.1029/2023MS004136","url":null,"abstract":"<p>The disposition of spectral solar irradiance in plant canopies is crucially important to understand processes such as photolysis of molecules amenable to absorbing actinic light. Thus, one objective of this study is to evaluate the most commonly applied radiative transfer approaches to estimate spectral irradiance as a function of plant canopy depth. Eight radiative transfer approaches are ascertained. Another objective is to determine the impacts of the spectral resolution assumed in radiative transfer calculations and model choice on key processes such as canopy absorption and reflection of irradiance. By comparing results from broadband-only and spectrally-resolved canopy radiative transfer, we aim to quantitatively determine the uncertainties associated with failing to resolve the sunlight spectra. We determine the optimal spectral resolution required to estimate canopy radiative transfer results such as air-chemistry-specific quantities related to photolysis of a select group of molecules. In addition, we evaluate techniques for binning leaf and soil optical properties. Results showed that high spectral resolution is ideally desired to compute photolysis of molecules such as ozone, nitrogen dioxide, nitrate radical, nitrous acid, and formaldehyde. For in-canopy photolysis of molecules, a waveband resolution of at least 10 nm is sufficient to obtain accurate estimates for most photochemical reactions. Positive reaction-dependent uncertainties in canopy-mean relative photolysis values for individual molecules can be as high as 30% compared to estimates derived with broad-band solar irradiance.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS004136","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488534","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":"Modifications to the CLASS Boundary Layer Model for Improved Interaction Between the Mixed Layer and Clouds","authors":"Kyoungho Ryu,&nbsp;Guido Salvucci","doi":"10.1029/2023MS004202","DOIUrl":"https://doi.org/10.1029/2023MS004202","url":null,"abstract":"<p>The impact of clouds on the mixed layer (ML) is critical for understanding the evolution of boundary layer humidity and temperature over the course of a day. We found that accounting for moistening of the cloud layer (CL) by humidity originating in the ML dramatically alters the interaction between the ML and the CL in a one-dimensional cloud-topped boundary layer model: Chemistry Land-surface Atmosphere Soil Slab (CLASS) (Vilà-Guerau de Arellano et al., 2015, https://doi.org/10.1017/CBO9781316117422). We demonstrate that enabling CLASS to moisten the lower CL improves the prediction of humidity (and the flux of humidity) both above and below the ML top (<i>h</i>). To account for this moistening, we propose a length scale, <i>L</i>, above <i>h</i>, over which mixing of mass fluxes into the environment occurs. The mass fluxes are assumed to decrease linearly from <i>h</i> to a height <i>L</i> meters above <i>h</i>, analogous to a convective plume detraining into the environment at a height-independent rate. Accounting for this process is accomplished by modifying the differential equations representing the growth of the jumps (sharp changes in humidity and temperature) at <i>h</i>. From analysis of a large number of diurnal Large Eddy simulations (covering approximately 11,000 different early morning initial conditions), we provide a regression model for parameterizing <i>L</i> from early morning weather variables. With the regression-based estimate of <i>L</i>, the modified model (CLASS-L) accounts for moistening the lower CL, and as a result, yields improved humidity dynamics, humidity flux profiles, and cloud growth under a broad range of conditions.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS004202","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488480","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":"Reduced-Order Modeling for Linearized Representations of Microphysical Process Rates","authors":"K. D. Lamb,&nbsp;M. van Lier-Walqui,&nbsp;S. Santos,&nbsp;H. Morrison","doi":"10.1029/2023MS003918","DOIUrl":"https://doi.org/10.1029/2023MS003918","url":null,"abstract":"<p>Representing cloud microphysical processes in large scale atmospheric models is challenging because many processes depend on the details of the droplet size distribution (DSD, the spectrum of droplets with different sizes in a cloud). While full or partial statistical moments of droplet size distributions are the typical variables used in bulk models, prognostic moments are limited in their ability to represent microphysical processes across the range of conditions experienced in the atmosphere. Microphysical parameterizations employing prognostic moments are known to suffer from structural uncertainty in their representations of inherently higher dimensional cloud processes, which limit model fidelity and lead to forecasting errors. Here we investigate how data-driven reduced-order modeling can be used to learn predictors for microphysical process rates in bulk microphysics schemes in an unsupervised manner from higher dimensional bin distributions. Using simulations characteristic of marine stratiform clouds, we simultaneously learn lower dimensional representations of droplet size distributions and predict the evolution of the microphysical state of the system. Droplet collision-coalescence, the main process for generating warm rain, is estimated to have an intrinsic dimension of three. This intrinsic dimension provides a lower limit on the number of degrees of freedom needed to accurately represent collision-coalescence in models. We demonstrate how deep learning based reduced-order modeling can be used to discover intrinsic coordinates describing the microphysical state of the system, where process rates such as collision-coalescence are globally linearized. These implicitly learned representations of the DSD retain more information about the DSD than typical moment-based representations.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS003918","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488481","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":"Implementation and Exploration of Parameterizations of Large-Scale Dynamics in NCAR's Single Column Atmosphere Model SCAM6","authors":"S. Cohen,&nbsp;A. Sobel,&nbsp;M. Biasutti,&nbsp;S. Wang,&nbsp;I. Simpson,&nbsp;A. Gettelman,&nbsp;I. Hu","doi":"10.1029/2023MS003866","DOIUrl":"https://doi.org/10.1029/2023MS003866","url":null,"abstract":"<p>A single column model with parameterized large-scale (LS) dynamics is used to better understand the response of steady-state tropical precipitation to relative sea surface temperature under various representations of radiation, convection, and circulation. The large-scale dynamics are parametrized via the weak temperature gradient (WTG), damped gravity wave (DGW), and spectral weak temperature gradient (Spectral WTG) method in NCAR's Single Column Atmosphere Model (SCAM6). Radiative cooling is either specified or interactive, and the convective parameterization is run using two different values of a parameter that controls the degree of convective inhibition. Results are interpreted in the context of the Global Atmospheric System Studies -Weak Temperature Gradient (GASS-WTG) Intercomparison project. Using the same parameter settings and simulation configuration as in the GASS-WTG Intercomparison project, SCAM6 under the WTG and DGW methods produces erratic results, suggestive of numerical instability. However, when key parameters are changed to weaken the large-scale circulation's damping of tropospheric temperature variations, SCAM6 performs comparably to single column models in the GASS-WTG Intercomparison project. The Spectral WTG method is less sensitive to changes in convection and radiation than are the other two methods, performing qualitatively similarly across all configurations considered. Under all three methods, circulation strength, represented in 1D by grid-scale vertical velocity, is decreased when barriers to convection are reduced. This effect is most extreme under specified radiative cooling, and is shown to come from increased static stability in the column's reference radiative-convective equilibrium profile. This argument can be extended to interactive radiation cases as well, though perhaps less conclusively.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS003866","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488471","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":"Parameterized Internal Wave Mixing in Three Ocean General Circulation Models","authors":"Nils Brüggemann,&nbsp;Martin Losch,&nbsp;Patrick Scholz,&nbsp;Friederike Pollmann,&nbsp;Sergey Danilov,&nbsp;Oliver Gutjahr,&nbsp;Johann Jungclaus,&nbsp;Nikolay Koldunov,&nbsp;Peter Korn,&nbsp;Dirk Olbers,&nbsp;Carsten Eden","doi":"10.1029/2023MS003768","DOIUrl":"https://doi.org/10.1029/2023MS003768","url":null,"abstract":"<p>The non-local model of mixing based on internal wave breaking, IDEMIX, is implemented as an enhancement of a turbulent kinetic energy closure model in three non-eddy resolving general circulation ocean models that differ in the discretization and choice of computational grids. In IDEMIX internal wave energy is generated by an energy flux resulting from near-inertial waves induced by wind forcing at the surface, and at the bottom, by an energy flux that parameterizes the transfer of energy between baroclinic and barotropic tides. In all model simulations with IDEMIX, the mixing work is increased compared to the reference solutions without IDEMIX, reaching values in better agreement with finestructure observations. Furthermore, the horizontal structure of the mixing work is more realistic as a consequence of the heterogeneous forcing functions. All models with IDEMIX simulate deeper thermocline depths related to stronger shallow overturning cells in the Indo-Pacific. In the North Atlantic, deeper mixed layers in simulations with IDEMIX are associated with an increased Atlantic overturning circulation and an increase of northward heat transports toward more realistic values. The response of the deep Indo-Pacific overturning circulation and the weak bottom cell of the Atlantic to the inclusion of IDEMIX is incoherent between the models, suggesting that additional unidentified processes and numerical mixing may confound the analysis. Applying different tidal forcing functions leads to simulation differences that are small compared to differences between the different models or between simulations with IDEMIX and without IDEMIX.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS003768","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141439630","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":"Simulating Global Terrestrial Carbon and Nitrogen Biogeochemical Cycles With Implicit and Explicit Representations of Soil Microbial Activity","authors":"William R. Wieder,&nbsp;Melannie D. Hartman,&nbsp;Emily Kyker-Snowman,&nbsp;Brooke Eastman,&nbsp;Katerina Georgiou,&nbsp;Derek Pierson,&nbsp;Katherine S. Rocci,&nbsp;A. Stuart Grandy","doi":"10.1029/2023MS004156","DOIUrl":"https://doi.org/10.1029/2023MS004156","url":null,"abstract":"<p>Nutrient limitation is widespread in terrestrial ecosystems. Accordingly, representations of nitrogen (N) limitation in land models typically dampen rates of terrestrial carbon (C) accrual, compared with C-only simulations. These previous findings, however, rely on soil biogeochemical models that implicitly represent microbial activity and physiology. Here we present results from a biogeochemical model testbed that allows us to investigate how an explicit versus implicit representation of soil microbial activity, as represented in the MIcrobial-MIneral Carbon Stabilization (MIMICS) and Carnegie-Ames-Stanford Approach (CASA) soil biogeochemical models, respectively, influence plant productivity, and terrestrial C and N fluxes at initialization and over the historical period. When forced with common boundary conditions, larger soil C pools simulated by the MIMICS model reflect longer inferred soil organic matter (SOM) turnover times than those simulated by CASA. At steady state, terrestrial ecosystems experience greater N limitation when using the MIMICS-CN model, which also increases the inferred SOM turnover time. Over the historical period, however, warming-induced acceleration of SOM decomposition over high latitude ecosystems increases rates of N mineralization in MIMICS-CN. This reduces N limitation and results in faster rates of vegetation C accrual. Moreover, as SOM stoichiometry is an emergent property of MIMICS-CN, we highlight opportunities to deepen understanding of sources of persistent SOM and explore its potential sensitivity to environmental change. Our findings underscore the need to improve understanding and representation of plant and microbial resource allocation and competition in land models that represent coupled biogeochemical cycles under global change scenarios.</p>","PeriodicalId":14881,"journal":{"name":"Journal of Advances in Modeling Earth Systems","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023MS004156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141439645","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}