Community Land Model (CLM5.0) Documentation

1 CLM5 DocumentationMar 23, 2020 CONTENTS1 History .. and Biogeochemical Processes ..112 Surface Characterization, Vertical Discretization, and Model Input Characterization .. Discretization .. Input Requirements ..183 Surface Radiative Transfer .. Albedos .. Zenith Angle ..354 Radiative Fluxes .. Fluxes ..395 Momentum, Sensible Heat, and Latent Heat Similarity Theory .. and Latent Heat Fluxes for Non-Vegetated Surfaces .. and Latent Heat Fluxes and Temperature for Vegetated Surfaces .. of Ground Sensible and Latent Heat Fluxes .. Vapor Pressure ..626 Soil and Snow Solution .. Change .. and Snow Thermal Properties ..747 Water.

2 Runoff, Surface Water Storage, and Infiltration .. Water .. Soils and Perched Water Table .. Sub-surface Runoff .. from glaciers and snow-capped surfaces ..90i8 Snow Covered Area Fraction .. Content .. Content .. and organic carbon and mineral dust within snow .. of snow layer .. Compaction .. Layer Combination and Subdivision .. 1009 Stomatal Resistance and of updates relative to the .. resistance .. scaling .. implementation .. 10710 Photosynthetic Model inputs and parameter estimations .. Model structure .. Numerical scheme .. 11311 Plant Roots .. Plant Hydraulic Stress .. 11712 Lake Vertical Discretization.

3 External Data .. Surface Albedo .. Surface Fluxes and Surface Temperature .. Lake Temperature .. Lake Hydrology .. 13813 Summary of updates relative to .. Overview .. Glacier regions and their behaviors .. Multiple elevation class scheme .. Computation of the surface mass balance .. 14414 Model for Scale Adaptive River Transport (MOSART) Overview .. Routing Processes .. Numerical Solution .. Parameters and Input Data .. Difference between and .. 15015 Urban Model (CLMU)15116 CN Introduction .. Tissue Stoichiometry .. 15717 Plant Autotrophic Respiration.

4 16118 Fixation and Uptake of Nitrogen (FUN) Introduction .. Boundary conditions of FUN .. Resolving N cost across simultaneous uptake streams .. Nitrogen Retranslocation .. Carbon expenditure on fixation and active uptake.. Modifications to allow variation in C:N ratios .. Calculation of N uptake streams from active uptake and fixation .. 17019 Carbon and Nitrogen Introduction .. Carbon Allocation for Maintenance Respiration Costs .. Carbon and Nitrogen Stoichiometry of New Growth .. Carbon Allocation to New Growth .. Nitrogen allocation .. 17620 Vegetation Phenology and General Phenology Flux Parameterization.

5 Evergreen Phenology .. Seasonal-Deciduous Phenology .. Stress-Deciduous Phenology .. Litterfall Fluxes Merged to the Column Level .. 18821 CLM-CN Pool Structure, Rate Constants and Parameters .. Century-based Pool Structure, Rate Constants and Parameters .. Environmental modifiers on decomposition rate .. N-limitation of Decomposition Fluxes .. N Competition between plant uptake and soil immobilization fluxes .. Final Decomposition Fluxes .. Vertical Distribution and Transport of Decomposing C and N pools .. Model Equilibration and its Acceleration .. 19922 External Nitrogen Summary of updates relative to.

6 Overview .. Atmospheric Nitrogen Deposition .. Biological Nitrogen Fixation .. Nitrification and Denitrification Losses of Nitrogen .. Leaching Losses of Nitrogen .. Losses of Nitrogen Due to Fire .. 20523 Plant Mortality Fluxes Leaving Vegetation Pools .. Mortality Fluxes Merged to the Column Level .. 20924 Non-peat fires outside cropland and tropical closed forest .. Agricultural fires .. Deforestation fires .. Peat fires .. Fire trace gas and aerosol emissions .. 219iii25 Methane Methane Model Structure and Flow .. Governing Mass-Balance Relationship .. CH4 Production.

7 Ebullition .. Aerenchyma Transport .. CH4 Oxidation .. Reactive Transport Solution .. Inundated Fraction Prediction .. Seasonal Inundation .. 22926 Crops and Summary of updates relative to the .. The crop Model .. The irrigation Model .. 24127 Transient Land Use and Land Cover Annual Transient Land Use and Land Cover Data .. Reconciling Changes in Area .. Mass and Energy Conservation .. Annual Transient Land Cover Dataset Development .. 24628 Dynamic Global What has changed .. 25129 Technical Documentation for Introduction .. The representation of ecosystem heterogeneity in FATES.

8 Initialization of vegetation from bare ground .. Allocation of biomass .. Canopy Structure and the Perfect Plasticity Approximation .. Radiation Transfer .. Photosynthesis .. Plant respiration .. Stomatal Conductance .. Allocation and Growth .. Control of Leaf Area Index .. Phenology .. Seed Dynamics and Recruitment .. Litter Production and Fragmentation .. Plant Mortality .. Fire (SPITFIRE) .. 28830 Biogenic Volatile Organic Compounds (BVOCs)29531 Dust Model29732 Carbon General Form for Calculating13C and14C Flux .. Isotope Symbols, Units, and Reference Standards .. Carbon Isotope Discrimination During Photosynthesis.

9 Radioactive decay and historical atmospheric14C and13C concentrations .. 30333 Land-Only Anomaly Forcing .. 307iv34 References309vviCLM5 DocumentationFebruary 2018 Technical Description of version of the Community Land Model (CLM)*Coordinating Lead Authors*David Lawrence, Rosie Fisher, Charles Koven, Keith Oleson, Sean Swenson, Mariana Vertenstein*Lead Authors*Ben Andre, Gordon Bonan, Bardan Ghimire, Leo van Kampenhout, Daniel Kennedy, Erik Kluzek, Ryan Knox,Peter Lawrence, Fang Li, Hongyi Li, Danica Lombardozzi, Yaqiong Lu, Justin Perket, William Riley, WilliamSacks, Mingjie Shi, Will Wieder, Chonggang Xu*Contributing Authors*Ashehad Ali, Andrew Badger, Gautam Bisht, Patrick Broxton, Michael Brunke, Jonathan Buzan, MartynClark, Tony Craig, Kyla Dahlin, Beth Drewniak, Louisa Emmons, Josh Fisher, Mark Flanner, Pierre Gentine,Jan Lenaerts, Sam Levis, L.

10 Ruby Leung, William Lipscomb, Jon Pelletier, Daniel M. Ricciuto, Ben Sander-son, Jacquelyn Shuman, Andrew Slater, Zachary Subin, Jinyun Tang, Ahmed Tawfik, Quinn Thomas, SimoneTilmes, Francis Vitt, Xubin ZengThe National Center for Atmospheric Research (NCAR) is operated by the nonprofit University Corporation for At-mospheric Research (UCAR) under the sponsorship of the National Science Foundation. Any opinions, findings,conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflectthe views of the National Science Center for Atmospheric Research P. O. Box 3000, Boulder, Colorado 80307-300 LIST OF FIGURES Figure Land biogeophysical, biogeochemical, and landscape processes simulated by CLM (adapted fromLawrence et al.)