EPA Hourly Emission Availability

[barronh]

Your name

Barron Henderson

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US EPA

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I have recently had several requests for hourly EPA inventories that could be used in GEOS-Chem. This discussion issue is meant to highlight which emission platforms are available and where you can get them. Right now, the 2016 modeling platform with monthly emissions and diurnal scale factors previously used with NEI 2011 are implemented. Hourly files are available for several datasets starting in 2002 and ending in 2017, with 2022 and 2023 on the way.

I always start with a little nomenclature to help with navigation. It may seem a bit pedantic, but it will help as you navigate the alphabet soup. I’m particularly aware because I’ve seen EPA emissions referred to as versions that they are not in publications.

Nomenclature:

The NEI is the inputs to the emissions modeling platform (EMP). The NEI is typically high level (NOx, VOC, PM at facility or county level). The EMP includes all the temporal allocation, spatial allocation, speciation, etc… basically everything that makes it ready for a model. The last two EMPs have been national emission inventory collaboratives (NEIC) efforts. Referencing the collaboration instead of EPA NEI helps give credit to all the collaborators. Lastly, the platforms numbered versions (v1, v2, etc) are actual a bit vague and may refer to one of several special year-letter combinations (i.e, 2016fj). The year is the met-year. The second letter in the combination the internal version. For now, don’t worry about the first letter. Not all versions go out, and several versions might get the label v1 or v2… not all of which go out.

With the nomenclature in mind, there are lots of options for CMAQ-ready emissions.

Options:

• If you want the 2016v2 regulatory platform at hourly resolution with sector separation, it is available at the Intermountain West Data Warehouse (IWDW).[1]
• If you want the EQUATES inventory for years 2002-2019, it’s hosted on a Google Drive for the continental 12US1 domain.[2] EQUATES is not the regulatory platform, but it is a well-documented inventory that was developed based on the regulatory platform.
• The 2017 platform is available thru the EPA_ANTHRO_EMIS archive.[5] They also have the 2014 platform… Maybe a bit out of date.
• The 2022 platform is in development and will be posted on AWS. Right now, we just have our met inputs[3]… The other inputs/outputs are still in process.
• The IWDW may also have 2022 in the future (not sure) and there is a new tool[4] for retrieving emissions by county or facility.
• Lastly, the EQUATES inventory (2002-2017) was used in the HTAPv3 harmonized inventory.[6] It was projected back to 2000 and forward to 2018 (which wasn’t available yet). So, you can also use HTAPv3 to get EQUATES… Unfortunately, HTAPv3 requires re-speciation and is only at monthly resolution. One of Randall’s students put HTAPv3 into GEOS-Chem, but I don’t know if they ever made it official. That was early on when HTAPv3 was still maybe beta.

When a dataset has a "merge" file (often merge_nobeis_norwc), it contains several sectors that are all surface level emissions. The definition of the sectors included are available in the "sectorlist" file in the SMOKE_INPUT folder. Understanding the sectors included can be useful in deciding how to process these files.

EQUATES and HTAPv3 are described in publications.[7,8] The other versions are usually overly documented in Technical Support Documents.

Hope that helps,

Barron

[1] https://views.cira.colostate.edu/iwdw/
[2] https://dataverse.unc.edu/dataset.xhtml?persistentId=doi:10.15139/S3/F2KJSK
[3] https://registry.opendata.aws/epa-2022-modeling-platform/
[4] https://www.epa.gov/air-emissions-modeling/2022v1-emissions-modeling-platform
[5] https://www2.acom.ucar.edu/wrf-chem/wrf-chem-tools-community
[6] https://edgar.jrc.ec.europa.eu/dataset_htap_v3
[7] Foley et al. doi:10.1016/j.dib.2023.109022
[8] Crippa et al. doi:10.5194/essd-15-2667-2023