VOCMIP input data repository

This is a input data repostitory for the VOCMIP experiment GMD - Introducing Volatile Organic Compound Model Intercomparison Project (VOCMIP)

Emissions

Emission Inputs

Anthropogenic emissions

CEDS_v2021: CEDS v2021 gridded emissions are available to 2019. Data can be downloaded here: CEDS v_2021_04_21 gridded emissions data | Datahub (PNNL).

Use the corrected version of the aircraft emission data: CEDS Version 2021-04-21 Aircraft Emissions Fix.

For Phase II simulations, a more recent release of CEDS will be used.

Biomass burning emissions

For biomass burning emissions, GFEDv4 is preferred.

Natural emissions

Model's own choice, but diagnose/specify in as much detail as possible. Total emissions (anthropogenic and natural) should be diagnosed and delivered (VOCMIP_diagnostics.xlsx).

Boundary conditions

H2 boundary conditions

For hydrogen surface concentration fields to drive the models for the years 2015-2019, the NOAA flask observations (Petron et al. 2024) have been used in the following manner. All stations that had monthly data for every month in a given year have been used to make smoothed monthly zonal fields using the lowess algorithm to a smoothness of 0.5.

Input file is available in the data/ folder of this repository: hydrogen_concentrations_lowess_201001-201912.nc

CH4 boundary conditions

The methane boundary conditions should be a latitudinally varying surface field, for example as provided for CMIP6 up to 2014. The annual global values should match the NOAA observations listed in Table 1. The methane concentration should be representative for the years 2015 to 2019.

Model's own choice how the boundary condition is implemented in the model, but the global values should match the NOAA global observations.

Table 1: Global evolution 2010-2019 of CH4 from the NOAA observations.

Year	Mean (ppb)
2010	1798.89
2011	1803.09
2012	1808.12
2013	1813.43
2014	1822.53
2015	1834.26
2016	1843.12
2017	1849.58
2018	1857.33
2019	1866.58

Files on 1 by 1 degree resolution are in the data/ folder of this repository:

• methane_concentrations_1by1_2010.nc
• methane_concentrations_1by1_2011.nc
• methane_concentrations_1by1_2012.nc
• methane_concentrations_1by1_2013.nc
• methane_concentrations_1by1_2014.nc
• methane_concentrations_1by1_2015.nc
• methane_concentrations_1by1_2016.nc
• methane_concentrations_1by1_2017.nc
• methane_concentrations_1by1_2018.nc
• methane_concentrations_1by1_2019.nc

Long-lived GHG and ODS boundary conditions

If possible, use ssp245, but it should at least correspond to the time period simulated.

Filenames

Each variable should be delivered in one (or several divided into different time slices if necessary) file for each experiment and model.

The format of the file name should be:

<variable_id>_<table_id>_<model_id>_vocmip_<experiment_id>_<member_id>_<time_range>.nc

Exceptions are for table_id fixed:

<variable_id>_<table_id>_<model_id>_vocmip.nc

These are fixed variables that do not change by time and experiments.

Table 2: Description of the different elements in the file names.

Element	Description
<variable_id>	The output variable name. Given as Output variable name in the spreadsheet.
<table_id>	Denote the temporal resolution such as monthly for monthly data, fixed for fixed data, and 3hourly for 3-hourly instantaneous data. Given as the name (ignore the dimensions, 3D, 2D) of the tab in the spreadsheet.
<model_id>	The name of your model.
<experiment_id>	The name of the experiment, exp following the experiment number given in Table 1 in GMD - Introducing Volatile Organic Compound Model Intercomparison Project (VOCMIP).
<member_id>	If more ensembles are run: r1, r2, etc.
<time_range>	Denotes the start and end date of the run on YYYYMM-YYYYMM or YYYYMMDD-YYYYMMDD format.

Example

hcho_monthly_OsloCTM3-v3X_vocmip_exp1_r1_201001-201912.nc