Community Earth System Model (CESM) simulations disentangling CO2 effects - PHYS (2 of 4)
Data files
Jan 11, 2025 version files 248.55 GB
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coupled_DEFmedslope_2xCO2_BGConly_03.tar.gz
133.12 GB
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coupled_SP_DEFmedslope_2xCO2_BGConly_05.tar.gz
115.43 GB
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README.md
10.34 KB
Abstract
It is widely recognized that water availability influences plant growth, but plants also exert a strong control on the water cycle. Plant transpiration constitutes about 60% of the total flux of water from the land to the atmosphere, and changes in vegetation coverage and ecosystem functioning can substantially alter land surface water and energy fluxes. A growing body of research has found that plant responses to increasing atmospheric CO2 can modify the water cycle. Rising CO2 concentrations at the land surface directly alter plant water use and land evapotranspiration, which previous studies have found can drive global-scale changes in precipitation, runoff, and streamflow. Concomitantly, the radiative effects of increasing CO2 modify atmospheric variables that affect plant functioning, such as temperature, vapor pressure deficit, and precipitation. Plant responses to these radiatively driven climate changes can further influence the hydrologic cycle. While multiple studies have found that plant responses to the physiological and radiative effects of CO2 can drive hydrologic impacts, there is limited consensus on the magnitude of plant responses’ overall influence. Significant uncertainty surrounds how plants respond to increasing CO2 and changing climate, as well as how a given plant change can impact the hydrologic cycle. This overall uncertainty is often discussed (e.g. IPCC 2021), but we still lack a systematic quantification of which processes are contributing the most to uncertainty in the hydrologic impact of plant responses to CO2. Ultimately, disentangling this uncertainty requires analysis of plants’ influence on the coupled biosphere-atmosphere system, because plant responses to increasing CO2 generate atmospheric feedbacks which can further modify land surface hydrology. In order to improve understanding of how plant responses to increasing atmospheric CO2 feed back on the global hydrologic cycle, we ran model experiments in the Community Earth System Model to systematically quantify the separate impacts of leaf-level and plant-level changes to different atmospheric drivers.
README: CESM simulations disentangling CO2 effects - PHYS
https://doi.org/10.5061/dryad.pvmcvdntz
Related datasets
We ran a suite of model experiments to disentangle the physiological and radiative effects of CO2, and to identify how leaf area responses modulate those effects. The model output from this suite of simulations is divided among four repositories which isolate the physiological (PHYS), radiative (RAD), and full physiological+radiative (FULL) effects of CO2 compared to the preindustrial control (PI). This repository contains model output from the physiological (PHYS) simulations.
Description of the data and file structure
This dataset is organized into two zipped files, each of which contains model output from a different simulation: coupled_DEFmedslope_2xCO2_BGConly_03.tar.gz
and coupled_SP_DEFmedslope_2xCO2_FULL_03.tar.gz
. Each of these files contain model output from simulations where the land experiences a doubling of CO2 and the atmosphere experiences preindustrial CO2 concentrations. coupled_DEFmedslope_2xCO2_BGConly_03
was run with dynamic leaf area (i.e., BGC mode) and coupled_SP_DEFmedslope_2xCO2_BGConly_05
was run with fixed leaf area (i.e., SP mode, where the fixed leaf area was determined from the preindustrial modeled leaf area climatology).
Within each of these zipped files, there are four folders: lnd
, atm
, rest
, and run_info
. lnd
and atm
contain model output in the form of postprocessed netcdf files from the land model and atmosphere model, respectively, where each file is a timeseries for a single variable. Each variable is described in the netcdf metadata. rest
contains the restart file from the end of the simulation, which can be used to continue the simulation for additional years, also in the form of netcdf files. Netcdf files can be opened and viewed using the xarray python package, HDFview, or Panoply. run_info
documents how simulations were configured in more detail, and is likely only relevant to people already familiar with running the Community Earth System Model (CESM). The CESM user guide describes how to run CESM and how different inputs (e.g., namelist settings) are used when running the model. run_info
contains the shell script used to generate the simulation (e.g., coupled_BGC_DEFmedslope_2xCO2_BGConly.sh
), the namelists
directory which contains files that document how each simulation was configured, and the SourceMods
directory which contains Fortran source files which document changes to the CESM code. All the files in run_info
can be opened in a text editor.
├── coupled_DEFmedslope_2xCO2_BGConly_03.tar.gz
│ ├── atm
│ │ └── proc
│ │ └── tseries
│ │ ├── day_1
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h1.PRECT.00410101-00510101.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h1.PRECT.00510102-00610101.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h1.PRECT.00610102-00710101.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h1.PRECT.00710102-00810101.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h1.PRECT.00810102-00910101.nc
│ │ │ └── ...(48 files total)
│ │ └── month_1
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h0.CLDHGH.004101-009012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h0.CLDHGH.009101-014012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h0.CLDHGH.014101-019012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h0.CLDHGH.019101-020012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h0.CLDLOW.004101-009012.nc
│ │ └── ... (244 files total)
│ ├── lnd
│ │ └── proc
│ │ └── tseries
│ │ ├── day_1
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h2.BTRAN2.00410101-00910101.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h2.BTRAN2.00910102-01410101.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h2.BTRAN2.01410102-01910101.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h2.BTRAN2.01910102-02001231.nc
│ │ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h2.EFLX_LH_TOT.00410101-00910101.nc
│ │ │ └── ... (144 files total)
│ │ └── month_1
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h0.ACTUAL_IMMOB.004101-009012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h0.ACTUAL_IMMOB.009101-014012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h0.ACTUAL_IMMOB.014101-019012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h0.ACTUAL_IMMOB.019101-020012.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.clm2.h0.AGNPP.004101-009012.nc
│ │ └── ... (1896 files total)
│ ├── rest
│ │ └── 0201-01-01-00000
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h0.0200-12.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.h1.0200-01-02-00000.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.i.0201-01-01-00000.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.r.0201-01-01-00000.nc
│ │ ├── coupled_DEFmedslope_2xCO2_BGConly_03.cam.rs.0201-01-01-00000.nc
│ │ └── ... (17 files total)
│ └── run_info
│ ├── coupled_BGC_DEFmedslope_2xCO2_BGConly.sh
│ ├── namelists
│ │ ├── user_nl_cam
│ │ ├── user_nl_clm
│ │ └── user_nl_cpl
│ └── SourceMods
│ └── src.clm
│ ├── BareGroundFluxesMod.F90
│ ├── CanopyFluxesMod.F90
│ ├── PhotosynthesisMod.F90
│ ├── README
│ ├── UrbanFluxesMod.F90
│ └── WaterFluxType.F90
└── coupled_SP_DEFmedslope_2xCO2_BGConly_05.tar.gz
├── atm
│ └── proc
│ ├── day_1
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h1.PRECT.00410101-00510101.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h1.PRECT.00510102-00610101.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h1.PRECT.00610102-00710101.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h1.PRECT.00710102-00810101.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h1.PRECT.00810102-00910101.nc
│ │ └── ... (48 files total)
│ └── month_1
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h0.CLDHGH.004101-009012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h0.CLDHGH.009101-014012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h0.CLDHGH.014101-019012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h0.CLDHGH.019101-020012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h0.CLDLOW.004101-009012.nc
│ └── ... (244 files total)
├── lnd
│ └── proc
│ └── tseries
│ ├── day_1
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h2.ANSHA_LN.00410101-00910101.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h2.ANSHA_LN.00910102-01410101.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h2.ANSHA_LN.01410102-01910101.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h2.ANSHA_LN.01910102-02001231.nc
│ │ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h2.ANSUN_LN.00410101-00910101.nc
│ │ └── ... (136 files total)
│ └── month_1
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h0.ANSHA_LN.004101-009012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h0.ANSHA_LN.009101-014012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h0.ANSHA_LN.014101-019012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h0.ANSHA_LN.019101-020012.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.clm2.h0.ANSUN_LN.004101-009012.nc
│ └── ... (920 files total)
├── rest
│ └── 0201-01-01-00000
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h0.0200-12.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.h1.0200-01-02-00000.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.i.0201-01-01-00000.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.r.0201-01-01-00000.nc
│ ├── coupled_SP_DEFmedslope_2xCO2_BGConly_05.cam.rs.0201-01-01-00000.nc
│ └── ... (17 files total)
└── run_info
├── coupled_SP_DEFmedslope_2xCO2_BGConly.sh
├── namelists
│ ├── user_nl_cam
│ ├── user_nl_clm
│ └── user_nl_cpl
└── SourceMods
└── src.clm
├── BareGroundFluxesMod.F90
├── CanopyFluxesMod.F90
├── PhotosynthesisMod.F90
├── README
├── UrbanFluxesMod.F90
└── WaterFluxType.F90
Methods
We ran simulations in a partially coupled configuration of the Community Earth System Model version 2 (CESM2; git tag: cesm2_3_beta03) using an active atmosphere (CAM6; git tag cam6_3_017), an active land model (CLM5; git tag branch_tags/PPE.n08_ctsm5.1.dev030), and a slab ocean which is based on q-fluxes from preindustrial simulations of the full dynamic ocean model. The land was initialized with the spun-up land state from the default model parameterization which includes the carbon content of soil and vegetation pools.
We ran a suite of model experiments to disentangle the physiological and radiative effects of CO2, and to identify how leaf area responses modulate those effects. The model output from this suite of simulations is divided among four repositories which isolate the physiological (PHYS), radiative (RAD), and full physiological+radiative (FULL) effects of CO2 compared to the preindustrial control (PI). All simulations branched from a preindustrial control simulation at year 41. Simulations in the PHYS, RAD, and FULL repositories were run for 160 additional years (i.e., ending at year 200), including spin up. This repository contains model output from simulations to quantify how leaf area responses influence the physiological effects of CO2. We ran two simulations: one where the leaf area was held fixed at preindustrial levels, and one where the leaf area was dynamically calculated by the model. Both simulations were equilibrium concentration-driven experiments where both the atmosphere experienced preindustrial CO2 (284.7 ppm) and the land experienced a doubling of CO2 (569.4 ppm). The spin up period is included in this model output.