ESM2025-N-cycle

This page is dedicated to the ESM2025 project (Earth System Models - European Project), especially for the N-cycle modelling. On this topic are working Marion Gehlen, Juliette Lathière, Didier Hauglustaine, Nicolas Vuichard and Karine Laurent, with the help of Anne Cozic.

You will find information on the evolution of the project on these different pages:

• Meetings: report of meetings every week;
• Intermediate Conclusions: some partial conclusions;
• Notebooks list: description of working documents;
• Pieces of code: few lines of code;
• References: some interesting references.

Last meeting

On Friday, 17th January 2025

With Anne and Nicolas.

Historical run is carried out in 1954, it goes slowly but no further problem has occured. As a result of the increase in emissions, the concentration also start to increase and the lifetime start to decrease.

To explain the difference between observations and concnetration, we can use the box model in order to determinehow much N₂O emissions can be added to start with the right slope on concentration. Nicolas talks about an article by Joos that explains nitrogen cycle during the paleoclimate.

There was also a interesting discussion with Didier about retroactions and feedbacks on N₂O cycle that can change lifetimes if they are taken into account. A study on the age of air needs to be read to make the same comparison; possibly with a CH₄ version of INCA. But, these were only preliminary discussions, bibliography needs to be done.

TO DO

• calculate the slope of observed concentration to determine the emission to be added,
• read Joos' article,
• better understand feedbacks on N₂O cycle and its behavior on lifetime + age of air,
• take care of restart used in coupled model (grids, files,..).

Last intermediate conclusions

Comparison with Prather's article

Reduction parameter of 1.3 on reaction rates to be in accordance with present day lifetime (observation). A previous value was 1.1 but it was only support on reaction rate and not on photolysis rate too.

Last notebooks/working documents

16. compare_ant_emissions.ipynb: Different methods are used to reconstruct nc files for N₂O emissions. This notebook served to visualisation of global emissions.
17. check_coeff_reconstruction_proxy.ipynb: with different method of reconstruction, result are different, this notebook explore coefficient used to reduce emissions for pre industrial period and after (coeff only per region and coeff per region and sector).
18. black_box_emissions_model.ipynb: little box model to compute concentration with given emissions and inverted model.

+ on Irene:

• on workdir: scripts_nco/prepare_N2OLOSS.job: will compute N2O total loss, N₂O photolyse loss, N₂O o1d loss and N₂O burden. This file creates some nc file on scratch directory (in Loss_files) and some txt file in place.
• on workdir: scripts_ferret: some scripts to draw more or less beautiful pictures.
• path to simulation directory (on work-gen2201-cont003):
  • with Orchidee_Quest: ESM2025/modipsl/config/LMDZORINCA_v6
  • with Orchidee_3: ESM2025/modipsl_v6.3/config/LMDZORINCA_v6
  • with Maureen's Code: extract_Maureen/modipsl/config/LMDZORINCA_v6

+ on Ciclad/Spirit?:

• INCAFLXANT_1970_1999.sh: bash script to create sflx_lmdz_ANT for irene (source code in ANT/McDuffie). The creation is made on datadir.

+ on Obelix:

• CEDS_transform/nco_transform_1970_1999_ncfiles.sh and nco_transform_country_1970_1999_ncfiles.sh: final step on nc files while transforming excel data into nc files.
• Interpol_With_rmp.ipynb: Notebook of O. Marti that transform eORCA1 grid into regular one (144x142 here).
• Ciclad_N2O_values.ipynb: Notebook to quickly see evolution of BBG and ANT emissions, needs a grep command on Ciclad and file transfer to Obelix.
• Transform_into_ncfile_preindustrial.sh: script corresponding to the notebook Transform_country_csv_to_nc_1970_2019.ipynb for preindustrial period.