Emissions for ACSIS


This page is maintained by Marcus Köhler (marcus).

General Overview



Emissions for the ACSIS WP 2.1 global model simulations are compiled from the ACCMIP-MACCity emissions and, for biomass burning emissions beyond 2008, from the ACCMIP interpolated emissions. Biogenic emissions are taken from the MEGAN-MACC database. This document describes the contributions from various sectors to the individual emitted chemical species as well as the computational processing steps. In the #Important Notes section further below the choices that were made for each individual species are documented.

Emissions File Locations

The original emissions input data files (0.5 × 0.5 degree resolution) and their processed derivatives are stored on the JASMIN UKCA group workspace. The UKCA netCDF emissions files with the time-varying monthly emissions fluxes for 1960–2020, generated from this data set, are found on the MONSooN HPC at the Met Office.

 (location will be shown here once files are released for general use) 

The files exist in separate versions for Gregorian and 360-day calendar settings and are stored in their respective subdirectories. The ancils files linking to these emissions are under version control, see ticket #578 on ANCIL trac (branch r4110_GA7.1_ACSIS).

Emissions File Versions

The input data, originally from various emissions databases, have been compiled into several sets of UKCA netCDF emissions files with monthly emission fluxes. These files will be used within the ACSIS model experiments. Time-varying emissions files span the period 1960–2020. Additionally, there are time-slice emissions which contain emission fluxes for a specific sub-period of these years.

  • Time-varying emissions, v2 (released 2017-10): In this version the emissions fluxes for 360-day calendar files are identical with those from the Gregorian calendar files. This decision was taken based on the methodology applied for CMIP6 emissions. It should be noted that this will result in slightly different annual total emissions between the two calendar versions and therefore the use of v2 will produce different results from v1. More netCDF meta-data has been included in this version in order to make the files more aligend with the CF standard requirements; in particular standard_name attributes have been included where possible.
    Note: In spite of the CF-1.5 conventions attribute (which is added automatically by the Iris Python library) none of the emissions files passes a CF compliance check without errors.

  • Periodic 1960 emissions, v1 (released 2017-07): These files contain the data of the first 12 months of the time-varying emissions and are used during the first decade (1950–1960) of the spin-up period of the ACSIS control runs, i.e. perpetual year 1960 emissions. These files contain improved meta data c.f. the time-varying v1 emissions. These improvements have been adopted in v2 of the time-varying emissions.
    Note: The use of the standard_name attribute in the netCDF files was deliberately abondoned due to the fact that there are no CF compliant standard names for all of the UKCA emissions available. In order to avoid inconsistent file attributes (i.e. some emission files with and some without standard_name attribute) it was decided to use the compulsory long_name attribute instead for all files.

  • Time-varying emissions, v1 (released 2017-05): These files (on the HPC in subdirectory v1) are the first draft or beta version of the complete emissions set and are used in the first group of ACSIS control experiments. Only volcanic SO2 and DMS land surface emissions are implemented as periodic 12-monthly files. All other files contain time-varying emissions fluxes. At the time of writing the numerical data is believed to be correct. However testing has so far been confined to short runs only (< 5 years duration). Known issues are with the meta data (the netCDF attributes) which are either inconsistent between the files or require additional information in order to be in better alignment with CF compliance. The meta data in this version is however complete in the sense that the model will accurately read and interpret the numerical data.

Tabular Overview of the ACSIS Emissions

The table below gives a concise overview of what data sources have been lumped into the individual emissions files. A more detailed description of the emissions is shown in the following sections on this page.

# Emissions File UKCA
Total Emissions
Year 1960
Total Emissions
Year 2000
Sources Sector
Year 2000
Source Data Files Timeseries
1 ukca_emiss_NO.nc NO 53.0 Tg NO 90.7 Tg NO anthropogenic 69 Tg NO MACCity_anthro_NOx_1960-2020_14412.nc NOx.zip
biomass burning 10 Tg NO 1960–2008: accmip_maccity_emissions_historic_NOx_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_NOx_biomassburning_YEAR_0.5x0.5.nc

soil 12 Tg NO (scaled) nox_soil_0.5_0.5.nc
2 ukca_emiss_NO_aircrft.nc NO 0.398 Tg NO 1.82 Tg NO anthropogenic 1.82 Tg NO MACCity_anthro_NOx_aviation_1960-2010_57144.nc NOx_aircrft.zip
3 ukca_emiss_CO.nc CO 850.5 Tg CO 1068 Tg CO anthropogenic 611 Tg CO MACCity_anthro_CO_1960-2020_12697.nc CO.zip
biomass burning 349 Tg CO 1960–2008: accmip_maccity_emissions_historic_CO_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_CO_biomassburning_YEAR_0.5x0.5.nc

biogenic 89 Tg CO MEGAN-MACC_biogenic_CO_1980-2010_66468.nc
oceanic 20 Tg CO POET_oceanic_CO_1990_84299.nc
4 ukca_emiss_CH4.nc CH4 (not used) (climatological boundary condition)
5 ukca_emiss_C2H6.nc C2H6 53.4 Tg C2H6
57.9 Tg C2H6
anthropogenic 3.3 Tg C2H6

7.7 Tg C2H4
3.3 Tg C2H2
Total: 15.4 Tg lumped C2H6



biomass burning 2.3 Tg C2H6

4.8 Tg C2H4
1.3 Tg C2H2
Total: 8.9 Tg lumped C2H6




biogenic 0.3 Tg C2H6

28.7 Tg C2H4
Total: 31.1 Tg lumped C2H6



oceanic 1.0 Tg C2H6

1.4 Tg C2H4
Total: 2.5 Tg lumped C2H6



6 ukca_emiss_C3H8.nc C3H8 26.8 Tg C3H8
30 Tg C3H8
anthropogenic 3.9 Tg C3H8

3.5 Tg C3H6
Total: 7.6 Tg lumped C3H8



biomass burning 1.2 Tg C3H8

2.6 Tg C3H6
Total: 3.9 Tg lumped C3H8




biogenic 0.03 Tg C3H8

14.9 Tg C3H6
Total: 15.6 Tg lumped C3H8



oceanic 1.3 Tg C3H8

1.5 Tg C3H6
Total: 2.9 Tg lumped C3H8



7 ukca_emiss_C5H8.nc C5H8 601 Tg C5H8 574 Tg C5H8 biomass burning 0.45 Tg C5H8 1960–2008: accmip_maccity_emissions_historic_isoprene_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_isoprene_biomassburning_YEAR_0.5x0.5.nc

biogenic 573 Tg C5H8 MEGAN-MACC_biogenic_isoprene_1980-2010_66428.nc
8 ukca_emiss_Me2CO.nc Me2CO 41.6 Tg Me2CO
43.0 Tg Me2CO
anthropogenic 1.1 Tg acetone

1.1 Tg other ketones
Total: 2.2 Tg lumped Me2CO



biomass burning 2.5 Tg acetone

0.83 Tg other ketones
Total: 3.3 Tg lumped Me2CO




biogenic 36.8 Tg acetone

0.58 Tg other ketones
Total: 37.4 Tg lumped Me2CO



9 ukca_emiss_HCHO.nc HCHO 10.4 Tg HCHO 12.2 Tg HCHO anthropogenic 3.2 Tg HCHO MACCity_anthro_formaldehyde_1960-2020_15023.nc HCHO.zip
biomass burning 4.5 Tg HCHO 1960–2008: accmip_maccity_emissions_historic_formaldehyde_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_formaldehyde_biomassburning_YEAR_0.5x0.5.nc

biogenic 4.5 Tg HCHO MEGAN-MACC_biogenic_formaldehyde_1980-2010_86024.nc
10 ukca_emiss_MeCHO.nc MeCHO 26.0 Tg MeCHO
25.7 Tg MeCHO
anthropogenic 1.2 Tg lumped acetaldehyde MACCity_anthro_other_aldehydes_1960-2020_4031.nc
biomass burning 3.3 Tg lumped acetaldehyde 1960–2008:



biogenic 18.0 Tg acetaldehyde

3.2 Tg other non-CH2O aldehydes
Total: 21.2 Tg lumped MeCHO



11 ukca_emiss_NH3.nc NH3 37.1 Tg NH3 53.8 Tg NH3 anthropogenic 37.5 Tg NH3 MACCity_anthro_NH3_1960-2020_98238.nc NH3.zip
biomass burning 6.4 Tg NH3 1960–2008: accmip_maccity_emissions_historic_NH3_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_NH3_biomassburning_YEAR_0.5x0.5.nc

oceanic 9.9 Tg NH3 ocn-nh3.cej
12 ukca_emiss_Monoterp.nc Monoterp 94.1 Tg Monoterpenes 94.9 Tg Monoterpenes biomass burning 0.3 Tg Monoterpenes 1960–2008: accmip_maccity_emissions_historic_terpenes_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_terpenes_biomassburning_YEAR_0.5x0.5.nc

biogenic 94.7 Tg Monoterpenes MEGAN-MACC_biogenic_monoterpenes_1980-2010_79169.nc
13 ukca_emiss_NVOC.nc NVOC 137.6 Tg CH3OH

51.6 Tg C

141 Tg CH3OH

53.0 Tg C

anthropogenic 2.0 Tg CH3OH MACCity_anthro_methanol_1960-2020_4015.nc NVOC.zip
biomass burning 8.5 Tg CH3OH 1960–2008: accmip_maccity_emissions_historic_CH3OH_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_CH3OH_biomassburning_YEAR_0.5x0.5.nc

biogenic 131 Tg CH3OH MEGAN-MACC_biogenic_methanol_1980-2010_66354.nc
14 ukca_emiss_DMS.nc DMS 0.88 Tg DMS 0.88 Tg DMS land surface 0.877 Tg DMS $UMDIR/ancil/atmos/n96e/ukca_emiss/cmip5/2000/v2/ukca_emiss_DMS.nc
15 ukca_emiss_SO2_low.nc SO2 45.7 Tg SO2 37.5 Tg SO2 anthropogenic Agriculture: 0.0 Tg SO2

Agric. Waste: 0.2 Tg SO2
Residential: 8.3 Tg SO2
Ships: 11.1 Tg SO2
Waste: 0.05 Tg SO2
Solvents: 0.0 Tg SO2
Transport: 4.3 Tg SO2
Industry (50%): 13.5 Tg SO2



16 ukca_emiss_SO2_high.nc SO2 46.7 Tg SO2 66.6 Tg SO2 anthropogenic Energy: 53.1 Tg SO2

Industry (50%): 13.5 Tg SO2



17 ukca_emiss_SO2_nat.nc SO2 29.2 Tg SO2 29.2 Tg SO2 volcanic from file meta-data:

Continuous: 25.2 Tg SO2
Explosive: 4.0 Tg SO2

contineous_volc.nc [sic]


18 ukca_emiss_BC_fossil.nc BC 0.94 Tg C 3.0 Tg C anthropogenic Agriculture: 0.0 Tg C

Ships: 0.13 Tg C
Solvents: 0.0 Tg C
Energy: 0.054 Tg C
Transport: 1.3 Tg C
Industry: 1.5 Tg C



19 ukca_emiss_BC_biofuel.nc BC 2.35 Tg C 2.1 Tg C anthropogenic Residential: 2.0 Tg C

Agric. Waste: 0.15 Tg C
Waste: 0.036 Tg C



20 ukca_emiss_BC_biomass.nc BC 2.31 Tg C 2.2 Tg C biomass burning 2.2 Tg C 1960–2008: accmip_maccity_emissions_historic_BC_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_BC_biomassburning_YEAR_0.5x0.5.nc

21 ukca_emiss_OC_fossil.nc OC 1.86 Tg C 4.2 Tg C anthropogenic Agriculture: 0.0 Tg C

Ships: 0.14 Tg C
Solvents: 0.0 Tg C
Energy: 0.39 Tg C
Transport: 1.5 Tg C
Industry: 2.3 Tg C



22 ukca_emiss_OC_biofuel.nc OC 7.99 Tg C 8.5 Tg C anthropogenic Residential: 7.8 Tg C

Agric. Waste: 0.70 Tg C
Waste: 0.047 Tg C



23 ukca_emiss_OC_biomass.nc OC 18.7 Tg C 18.4 Tg C biomass burning 18.4 Tg C 1960–2008: accmip_maccity_emissions_historic_OC_biomassburning_YEAR_0.5x0.5.nc

2009–2020: accmip_interpolated_emissions_RCP85_OC_biomassburning_YEAR_0.5x0.5.nc


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Description of the Emissions

This section describes which data sources have been collated to compile the ACSIS emissions. For MACCity emissions the description has partly been taken verbatim from the metadata descriptor files.

ACCMIP decadal emissions

A consistent emissions inventory for 1850–2100 was developed in support of IPCC AR5 by using historic emissions from 1850 to 2000 and four RCP scenarios beyond the year 2000 until 2100. These emissions are available on a decadal basis as monthly means and are described in Lamarque et al. (2010). For further details on the RCP inventories see Van Vuuren et al. (2011).

 Download_icon Download link: http://accmip-emis.iek.fz-juelich.de/data/accmip/gridded_netcdf/decadal/

ACCMIP interpolated emissions

The decadal monthly mean ACCMIP emissions were interpolated linearly in time to obtain monthly emissions data for each year from 1850 to 2100. The linear time interpolation took into account the variation in the sector-specific time stamps which were representative of the respective decade. No seasonal or interannual variability is considered in this data set.

 Download_icon Download link: http://accmip-emis.iek.fz-juelich.de/data/accmip/gridded_netcdf/accmip_interpolated/

ACCMIP-MACCity emissions

As part of MACC and CityZen EU projects the linear time interpolated historic ACCMIP and the RCP 8.5 emission datasets have been further developed on a yearly basis for the period 1960-2020 for the anthropogenic emissions, and 1960-2008 for the biomass burning emissions.

A seasonal cycle was applied for each sectoral layer, and the VOCs species emissions have been lumped to 21 species. ACCMIP MACCity biomass burning emissions comprise all emissions resulting from natural and manmade surface vegetation fires including emissions from the combustion of soil organic matter (duff or peat). Emissions emanating from the combustion of agricultural wastes (e.g. burning rice stubble) or biofuels (e.g. cow dung, charcoal) are excluded.

The ACCMIP MACCity biomass burning emissions are quantified for two separate sectors, namely emissions from (a) forest and (b) grassland and savannah fires. (a) comprises all biomass burning emissions from areas classified as tropical or extratropical forest in the GFEDv2 predominant vegetation cover map (van der Werf et al. 2006) while (b) comprises all biomass burning emissions from areas classified as savannah/herbaceous. Additional information on the methodology can be found in Lamarque et al. (2010), Granier et al. (2011), and Diehl et al. (2012).

 Download_icon Download link: http://eccad.sedoo.fr/

Other Emissions Sources

Biogenic emissions originate from the MEGAN-MACC database. Oceanic emissions for several alkanes and alkenes are taken from the POET database which provides one year (1990) of data in 12 monthly fluxes for each species. This annual cycle is applied perpetually to all years. The same applies for oceanic NH3 emissions which are taken from Bouwman et al. (1997). Soil emissions for oxides of nitrogen (NOx) are applied according to Yienger & Levy (1995) and are scaled to 12.0 Tg NO per year based on personal communication (consistent with earlier UM emissions code), the origin of this annual amount remains unverified. The origin of the soil emissions data file is not directly traceable (provided originally by Paul Telford?).

 Download_icon Download link: http://eccad.sedoo.fr/

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Processing of Emissions for ACSIS

The ACSIS control runs will be nudged to ECMWF ERA Interim Analyses. As such we opted to use ACCMIP-MACCity emissions in order to take full advantage of the included seasonality for the anthropogenic sectors and inter-annual variability in the biomass burning emissions. For ACSIS a full set of time-varying UKCA emissions will be prepared for the period 1960–2020.

Issues to resolve:

  • While anthropogenic MACCity emissions are available until 2020 ("historic" emissions until 2000, then RCP8.5 scenario emissions until 2020), the biomass burning emissions only extend to 2008 ("historic" emissions). We therefore use the ACCMIP linearly interpolated biomass burning emissions (forest and savannah fires only) from RCP8.5 for the years 2009–2020 to extend the biomass burning emissions until 2020.
  • It is unclear whether the emission rates are valid for a 360-day calendar or for a Gregorian 365/366-day calendar. Several email exchanges with Claire Granier (lead author of the key reference for MACCity) and staff from IASS Potsdam and TNO (NL), who were involved in generating the emissions data, has resulted in the conclusion that emission rates are most likely valid for a Gregorian calendar. Comparison with tabular listings of annual total emissions from the ECCAD database (where the data was obtained from) confirm that calculated annual total emissions are closer to the expected value when assuming a Gregorian calendar. However a small discrepancy remains.
  • MACCity emissions beyond the historic period follow RCP8.5 which is not consistent with the approach used for the CCMI integrations (there RCP6.0 was used). We assume that the differences will be small for the first 20 years after 2000.

Code Repository

The source code of the individual programs which were used for the processing of the raw emissions data is under version control and can be downloaded from the repository.

 github_icon Github repository link: https://github.com/acsis-project/emissions

Step-by-Step Methodology

The emissions data is stored on the JASMIN UKCA group workspace:


The UKCA netCDF emissions files are produced in 9 steps for each species with the following IDL and Python programs:

1a.   ACCMIP_interpolated_SPEC_combine_sectors.pro:
Reads gzipped raw emissions data from the ACCMIP-interpolated data set and combines all sectors into one monthly emissions flux. Annual netCDF files with combined emissions flux for one species are produced. ASCII files with annual totals for each individual sector from 1950 onwards are produced. The purpose is to compare the output with MACCity data, as the difference in the anthropogenic emissions should be only small.

The above step is not strictly required to generate the ACSIS emissions and serves only to generate a data set against which the MACCity emissions can be compared.

1b.   ACCMIP-MACCity_anthrop_SPEC_combine_sectors.pro:
Splits the combined MACCity anthropogenic emissions mass flux into annual files for the individual years 1960–2020 and adjusts the time stamp for the monthly emission fluxes to fall exactly on the mid-point of the month by assuming a Gregorian 365/366-day calendar (days since 1960-01-01). February date stamps are corrected for leap years.

2.   ACCMIP-MACCity_bioburn_SPEC_combine_sectors.pro:
Reads annual netCDF data files containing data from the two MACCity biomass burning sectors and combines them into one joint bioburn mass flux. Annual data files with monthly data are written out, however here the time stamp remains unchanged from the raw data (days since 1850-01-01). This applies to the entire historic time period of 1960–2008.

3.   ACCMIP_interpolated_SPEC_bioburn_2009-2020.pro:
Produces annual netCDF emission files with emission fluxes from biomass burning emissions from the ACCMIP interpolated data set over the years 2009–2020. These output files are then used to complement the MACCity historic biomass burning emissions beyond 2008 util 2020 in order to have a complete anthropogenic and biomass burning dat aset for 1960–2020. For consistency with the MACCity anthropogenic data it is advised to select the RCP8.5 scenario. The time stamp remains unchanged from the raw data files (days since 1850-01-01).

At this stage two sets of annual data files for 1960–2020 with combined emission fluxes have been created – one for anthropogenic and the other for biomass burning emissions.

4.   The ACCMIP_interpolated bioburn emissions files need to be symbolically linked into the directory of the MACCity bioburn emissions.

5.   Using the NCO operators by running the executable file script the annual netcdf files will be concatenated again along the time dimension with the data sorted into the correct annual sequence. This needs to be done in both the anthrop and bioburn emissions directories and the resulting output is temporarily stored in a file called newfile.nc (one file each for anthrop and bioburn emissions, confusingly they have the same name).

6.   MEGAN-MACC_biogenic_SPEC_preprocess.pro:
Extends the biogenic emissions from the MEGAN-MACC database to 1960–2020 by apply for each missing year a five year average at the respective end of the time series. In other words, biogenic emissions 1960-1979 are perpetual annual cycles of the averages of 1980–1984. Biogenic emissions 2011–2020 are perpetual averages of 2006–2010.

7.   POET_oceanic_SPEC.pro:
For CO, C2H6 and C3H8 12 monthly fluxes of oceanic emissions are read from POET data and regriddged to 0.5 × 0.5 degrees. This data will be added in the following step to the combined emissions flux when necessary.

8.   combine_all_sources_SPEC_1960-2020.pro:
In this step these two temporary MACCity files and the preprocessed biogenic emissions file are combined into one single netcdf file per emitted specie and the time stamp of the MACCity anthropogenic data (Gregorian calendar) is used. If the species requires additional emissions from other sectors (ocean, soil, etc) these fluxes are also included here. Further meta data is added in netcdf attributes and the resulting output file (combined_sources_SPEC_1960-2020.nc) represents the combined emissions flux data file at the original MACCity resolution (0.5 × 0.5 degrees) which can now be used to create UKCA emissions files at the horizontal resolution of choice.

9.   regrid_SPEC_emissions_n96e_greg.py:
This Python 2.7 script (provided by Luke Abraham) is used to generate UKCA emissions files. It uses an area weighted regridding algorithm from the Python/Iris library and defines the required meta-data required by the UKCA model.

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Important Notes

  • Oceanic sources: Oceanic emissions of CO, C2H6, C2H4, C3H8 and C3H6 are taken from the POET inventory for 1990 which contains one annual cylce with 12 monthly fluxes. These fluxes are applied perpetually to all years of the time series. Oceanic NH3 emissions are taken from Bouwman et al. (1997).
  • Soil emissions: Soil emissions of NOx should be distributed according to Yienger & Levy (1995). They are included from a separate legacy file (one annual cycle, as oceanic emissions) the origin of which is not traceable (Paul Telford?). The soil emissions are scaled to 12.0 Tg NO/yr and perpetually applied to all years. The rationale for scaling to this annual total amount comes from legacy emissions code, but no reference is given.
  • Volcanic emissions: Volcanic SO2 emissions are taken from AeroCom phase 1 data for explosive and continuously emitting volcanoes. The UKCA netcdf emissions file has been produced by Anja Schmidt and Alistair Sellar as an interim solution for UKESM-1 and provided to us for use in the ACSIS control experiment in $UMDIR emissions subdirectory aerocom/v1/. See also the discussion in Ticket #358 on ANCIL trac and Dentener et al. (2006).
  • Aviation sector emissions: NOx and BC from aviation are only available until 2010, and not until 2020 like all other anthropogenic emissions. At the time of writing Aircraft BC is used in the stand-alone GLOMAP model however it is not yet included in UKCA. Therefore only NOx emissions from aviation are used, and emissions of the year 2010 are perpetually applied for the remaining decade from 2011-2020.
    Aircraft emissions originate from the ATTICA aircraft emissions database and are provided on 25 vertical flight levels with 2,000 ft spacing (610 m) above MSL. In the absence of further information these were taken as absolute altitudes above MSL (Note: Flight levels are actually pressure altitudes based on the ICAO Standard Atmosphere, using surface level pressure reduced to 1013.25 hPa).
    When using the model's actual gridbox altitudes above MSL we encounter a problem due to the fact that the emissions orography does not match with the model's orography. A substantial proportion of emissions (>15% of mass) would be emitted below the model's surface altitude. For this reason we make the assumption that target heights in the emissions file are given relative to the surface altitude (which is likely to be incorrect). This assumption however allows us to use hybrid model heights (terrain-following heights) as target altitudes. This will likely result in an unrealistic skewing of the emissions distribution in the lower troposphere, but as most of the emissions are released in the UTLS region we expect the impact of this skewed distribution to be small.
    Further, note that UKCA expects aircraft emissions to be released as kg m-2 s-1 on each model level which is not CF-compliant (as opposed to kg m-3 s-1, see entries related to "aviation" in CF Standard Name Table, Version 44, 23 May 2017).
  • NOx surface emissions: MACCity Biomass Burning and ACCMIP Biomass Burning emissions of NOx are expressed as NO (nitric oxide). The standard name attribute of the MACCity anthropogenic NOx emissions is "tendency_of_atmosphere_mass_content_of_nox_expressed_as_nitrogen_due_to_emission", however the molecular weight is given as 30 (g mol-1), i.e. the value of nitric oxide. Therefore we assume that MACCity anthropogenic NOx emissions are also provided as nitric oxide (NO) as in the biomass burning emissions and not as atomic nitrogen.
  • C2H6 and C3H8 emissions: Ethane is lumped with ethene and ethyne, whereas propane is lumped with propene. The general rule is that alkenes and alkynes are lumped with the alkane having the corresponding number of carbon atoms.
  • C5H8 emissions: Isoprene emissions require meta-data adjustment to allow for diurnal scaling.
  • Me2CO emissions: Acetone is lumped with other ketones. In the MACCity emissions this lumped species group consists of 2-butanone (MEK), pentanones, heptanones, and octanones. In MEGAN-MACC they consist of 2-butanone + geranyl_acetone + met_heptenone + neryl_acetone + heptanone (K. Sindelarova, pers. comm., 27-Mar-2017).
  • MeCHO emissions: In both the MACCity and the ACCMIP_interpolated bioburn emissions inventories acetaldehyde (ethanal, C2H4O or MeCHO in UKCA) is the only alkanal contained in the file labelled *_other-alkanals_* (note that formaldehyde is provided in a separate data file). For the anthropogenic MACCity emissions this is not made explicitly clear from the available meta-data. However given that the molar mass in the file *_anthro_other_aldehydes_* is the correct value for ethanal, it is presumed that this file contains emissions of only this one species (which would be consistent with the corresponding biomass burning emissions). NOTE: The 1982 ethanal bioburn emissions file has corrupted coordinates. This was corrected and reported to the database managers. Biogenic emissions of acetaldehyde consist of a separate MEGAN-MACC file for acetaldehyde and another lumped group of non-CH2O (non-MeCHO) aldehydes, which contain benzaldehyde + decanal + heptanal + nonanal + nonenal + octanal + hexanal + hexenal_c3 + hexenal_t2 + pentanal + myrtenal (K. Sindelarova, pers. comm., 23-Mar-2017).
  • NVOC emissions: The exact requirements for the composition of NVOC emissions remained unclear. Other than stated in Table 23 of the UM Documentation Paper 084 (for version 10.6.1, last updated 2016-11-14) the NVOC emissions are not required for the aerosol chemistry (Ken Carslaw, pers. comm. March 2017). The emissions flux is interpreted by the model as methanol and apparently contained in the past various lumped BVOC emissions. Meanwhile biogenic emissions of isoprene, CH4 wetlands, monoterpenes, acetone and aldehydes are dealt with in more detail elsewhere in the emissions. Hence only methanol emissions were included in this file. The model code seems to require these emissions to be expressed as carbon and as a precaution they were hence scaled to a carbon flux. It has not been tested whether this conversion remains a requirement for the netcdf emissions.
  • DMS emissions: MACCity provides DMS emissions from biomass burning with interannual variability. However, the total emitted DMS from the land surface in MACCity is of the order of 0.1 to 0.2 Tg[DMS] per year. The existing DMS emissions in UKCA have no seasonal or interannual variation (constant flux) and amount to 0.88 Tg[S] per year. In the absence of more comprehensive data for land-based emission sources it was decided to fall back onto the existing time-averaged netcdf emissions for DMS which are applied perpetually for all years. The origin of the land-based DMS emissions in the model has therefore not been traced here.
    Oceanic DMS emissions are calculated by the model and are dependent on physical conditions at the ocean surface. This makes use of a further ancillary file (based on Kettle et al. (1999)) which remains unchanged from the standard model configuration. See also the discussion in Ticket #154 on the Global Atmosphere Trac.
  • SO2 emissions: For the anthropogenic sectors "solvent production and use" and "agricultural production" the MACCity SO2 emissions are zero at all times for all gridboxes. In ACCMIP these sectors do not exist for SO2 emissions. Emissions of the industry sector are split 50/50% into SO2_high and SO2_low emissions, which is consistent with the treatment of SO2 emissions in CMIP5 (Jones et al. (2011)) and in CMIP6 (S. Rumbold, pers. comm., 31-Mar-2017).
  • Black carbon emissions: For the anthropogenic sectors "solvent production and use" and "agricultural production" the MACCity BC emissions are zero at all times for all gridboxes. In ACCMIP these sectors do not exist for BC emissions.
    Biomass BC emissions are used as a 2D field and spread over the lowest 3 km of the model domain, using netcdf attributes ("high_level").
  • Organic carbon emissions: As for BC the solvent and agr.prod. sectors are not available. The model uses organic carbon as organic matter, however the conversion factor is applied by the model and emissions are provided as mass flux of carbon. Biomass emissions are treated in the same way as those from BC.

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Processing of all the emissions data and the development of this wiki page were carried out by Marcus Köhler (marcus) at the University of Cambridge.
Contributions from and involvement of colleagues (in no particular order) as part of the emissions generation process:

  • Email exchanges with: Luke Abraham, Alex Archibald, Alistair Sellar, Steven Rumbold, Steven Turnock, Mohit Dalvi, Anja Schmidt, Colin Johnson, Nicolas Bellouin, Katerina Sindelarova, Erika von Schneidemesser, Claire Granier, Sabine Darras, Tim Butler, Kirsty Pringle and Ken Carslaw group
  • Meeting with the Ken Carslaw group in Leeds: Ken Carslaw, Kirsty Pringle, Anja Schmidt, Catherine Scott, Masaru Yoshioka, Leighton Regayre
  • Data files: Kirsty Pringle (oceanic NH3), Steven Rumbold (draft CMIP6 files), Alistair Sellar & Anja Schmidt (volcanic SO2), Ines Heimann (soil NOx)
  • Source code: Kirsty Pringle shared emissions source code related to PEGASOS project (originally by M. Woodhouse?), Ines Heimann shared UKCA emissions processing code for UM 8.4 (P. Telford?), Luke Abraham and Paul Griffiths shared grid interpolation code
  • Volcanic emissions: Advice from Anja Schmidt, Alistair Sellar
  • Documentation: Received from Matt Woodhouse, Steven Turnock


ACCMIP & MACCity Emissions

  • Granier, C., Bessagnet, B., Bond, T., D’Angiola, A., Denier van der Gon, H., Frost, G. J., Heil, A., Kaiser, J. W., Kinne, S., Klimont, Z., Kloster, S., Lamarque, J.-F., Liousse, C., Masui, T., Meleux, F., Mieville, A., Ohara, T., Raut, J.-C., Riahi, K., Schultz, M. G., Smith, S. J., Thompson, A., van Aardenne, J., van der Werf, G. R., and van Vuuren, D. P. (2011), Evolution of anthropogenic and biomass burning emissions of air pollutants at global and regional scales during the 1980–2010 period, Clim. Change 109, 163–190, doi:10.1007/s10584-011-0154-1.
  • Diehl, T., Heil, A., Chin, M., Pan, X., Streets, D., Schultz, M., and Kinne, S. (2012), Anthropogenic, biomass burning, and volcanic emissions of black carbon, organic carbon, and SO2 from 1980 to 2010 for hindcast model experiments, Atmos. Chem. Phys. Discuss. 12, 24895–24954, doi:10.5194/acpd-12-24895-2012.
  • Lamarque, J.-F., Bond, T. C., Eyring, V., Granier, C., Heil, A., Klimont, Z., Lee, D., Liousse, C., Mieville, A., Owen, B., Schultz, M. G., Shindell, D., Smith, S. J., Stehfest, E., Van Aardenne, J., Cooper, O. R., Kainuma, M., Mahowald, N., McConnell, J. R., Naik, V., Riahi, K., and van Vuuren (2010), Historical (1850–2000) gridded anthropogenic and biomass burning emissions of reactive gases and aerosols: methodology and application, Atmos. Chem. Phys. 10, 7017–7039, doi:10.5194/acp-10-7017-2010.
  • van der Werf, G. R., Randerson, J. T., Giglio, L., Collatz, G. J., Kasibhatla, P. S., and Arellano Jr., A. F (2006), Interannual variability in global biomass burning emissions from 1997 to 2004, Atmos. Chem. Phys. 6,3423-3441 doi:10.5194/acp-6-3423-2006.

MEGAN-MACC Emissions

  • Guenther A. B., Jiang, X., Heald, C. L., Sakulyanontvittaya, T., Duhl, T., Emmons, L. K., Wang, X. (2012), The Model of Emissions of Gases and Aerosols from Nature version 2.1 (MEGAN2.1): an extended and updated framework for modeling biogenic emissions, Geosci. Model Dev. 5, 1471–1492, doi:10.5194/gmd-5-1471-2012.
  • Sindelarova, K., Granier, C., Bouarar, I., Guenther, A., Tilmes, S., Stavrakou, T., Müller, J.-F., Kuhn, U., Stefani, P., and Knorr, W. (2014), Global dataset of biogenic VOC emissions calculated by the MEGAN model over the last 30 years, Atmos. Chem. Phys. 14, 10725–10788, doi:10.5194/acp-14-9317-2014.

POET Emissions

  • Granier, C., J.F. Lamarque, A. Mieville, J.F. Muller, J. Olivier, J. Orlando, J. Peters, G. Petron, G. Tyndall, S. Wallens (2005), POET, a database of surface emissions of ozone precursors, http://www.pole-ether.fr/eccad
  • Olivier J., J. Peters, C. Granier, G. Petron, J.F. Muller and S. Wallens (2003), Present and future surface emissions of atmospheric compounds, POET report #2, EU project EVK2-1999-00011

Other References

  • Bouwman, A. F., D. S. Lee, W. A. H. Asman, F. J. Dentener, K. W. Van Der Hoek, and J. G. J. Olivier (1997), A global high-resolution emission inventory for ammonia, Global Biogeochem. Cycles 11(4), 561–587, doi:10.1029/97GB02266.
  • Dentener, F., Kinne, S., Bond, T., Boucher, O., Cofala, J., Generoso, S., Ginoux, P., Gong, S., Hoelzemann, J. J., Ito, A., Marelli, L., Penner, J. E., Putaud, J.-P., Textor, C., Schulz, M., van der Werf, G. R., and Wilson, J. (2006), Emissions of primary aerosol and precursor gases in the years 2000 and 1750 prescribed data-sets for AeroCom, Atmos. Chem. Phys. 6, 4321–4344, doi:10.5194/acp-6-4321-2006.
  • Jones, C. D., et al. (2011), The HadGEM2-ES implementation of CMIP5 centennial simulations, Geosci. Model Dev. 4, 543–570, doi:10.5194/gmd-4-543-2011.
  • Kettle, A. J., et al. (1999), A global database of sea surface dimethylsulfide (DMS) measurements and a procedure to predict sea surface DMS as a function of latitude, longitude, and month, Global Biogeochem. Cycles 13(2), 399–444, doi:10.1029/1999GB900004.
  • Yienger, J. J., and H. Levy II (1995), Empirical model of global soil-biogenic NOχ emissions, J. Geophys. Res. 100(D6), 11447–11464, doi:10.1029/95JD00370.