Selected figures from Wenzel et al. (2016) are reproduced with recipe_wenzel16nat.yml. Gross primary productivity (gpp) and atmospheric CO2 concentrations at the surface (co2s) are analyzed for the carbon cycle - concentration feedback in the historical (esmHistorical) and uncoupled (esmFixCLim1, here the carbon cycle is uncoupled to the climate response) simulations. The recipe includes a set of routines to diagnose the long-term carbon cycle - concentration feedback parameter (beta) from an ensemble of CMIP5 models and the observable change in the CO2 seasonal cycle amplitude due to rising atmospheric CO2 levels. As a key figure of this recipe, the diagnosed values from the models beta vs. the change in CO2 amplitude are compared in a scatter plot constituting an emergent constraint.
Recipes are stored in recipes/
- recipe_wenzel16nat.yml
Diagnostics are stored in diag_scripts/carbon_ec/
- carbon_beta: (1) scatter plot of annual gpp vs. annual CO2 and
(2) barchart of gpp(2xCO2)/gpp(1xCO2); calculates beta for emergent constraint (carbon_co2_cycle.ncl)
- carbon_co2_cycle.ncl: (1) scatter plot of CO2 amplitude vs. annual CO2, (2) barchart of sensitivity of CO2 amplitude to CO2, (3) emergent constraint: gpp(2xCO2)/gpp(1xCO2) vs. sensitivity of CO2 amplitude to CO2, (4) probability density function of constrained and unconstrained sensitivity of CO2 amplitude to CO2
Note
Make sure to run this recipe setting output_file_type: pdf
in the config_user.yml
file or using the CLI flag --output_file_type=pdf
.
Script carbon_beta.ncl
Required Settings (scripts)
- styleset: project style for lines, colors and symbols
Optional Settings (scripts)
- bc_xmax_year: end year to calculate beta (default: use last available year of all models)
- bc_xmin_year: start year to calculate beta (default: use first available year of all models)
Required settings (variables)
none
Optional settings (variables)
none
Script carbon_co2_cycle.ncl
Required Settings (scripts)
- nc_infile: path of netCDF file containing beta (output from carbon_beta.ncl)
- styleset: project style for lines, colors and symbols
Optional Settings (scripts)
- bc_xmax_year: end year (default = last year of all model datasets available)
- bc_xmin_year: start year (default = first year of all model datasets available)
Required settings (variables)
- reference_dataset: name of reference datatset (observations)
Optional settings (variables)
none
- co2s (atmos, monthly mean, plev longitude latitude time)
- gpp (land, monthly mean, longitude latitude time)
- ESRL: Earth System Research Laboratory, ground-based CO2 measurements
- Wenzel, S., Cox, P., Eyring, V. et al., 2016, Projected land photosynthesis constrained by changes in the seasonal cycle of atmospheric CO2. Nature 538, 499501, doi: doi.org/10.1038/nature19772