2016 NEI airport emissions_ vertical allocation/distribution

Hi… I had a question about airport inventory. I understand that the emissions are categorized as surface emissions and comprise mainly of LTO.

Does the LTO consist of the climb and approach emissions which would probably be at levels above the surface. I’m trying to get a clearer idea about the vertical distribution of airport emissions.

Current NEI only captures up to 3,000 ft height LTO emissions as a part of their aircraft emissions inventory. Any emissions above 3,000ft are not considered in the current version of NEI. However, there has been an effort at EPA to develop full trajectory 3-dimensional hourly aircraft emissions inventory including emissions from the cruising.

Thanks a bunch @bbaek! That clarifies a lot. A bit of a few general questions. I’m not sure on this, but could the AEDT program generate full flight emissions (LTO and those at higher altitudes)? And in order to do that, it would more than LTO data…correct?

Yes, AEDT can generate aircraft emissions for LTO (<3000 ft) and emissions above 3000 ft.

Currently, the modeling platform and NEI only include airport / aircraft emissions up to 3000 ft and they are all vertically allocated to the first model layer (ground level). The bulk of the emissions actually do occur at ground level. However, in the future we hope to be able to reflect more of a vertical distribution of the aircraft sources. The hemispheric platform actually does include climbing and descent and cruise emissions.

@eyth.alison, @huangj1311 and @bbaek Thanks for this clarification. Appreciate it. A follow up question, @bbaek mentioned that in future, NEI would include 3D aircraft emissions. Please, will this be released with the next NEI?

We do not expect this to be in 2020 NEI. There are a number of complex issues involved with the emissions not really being at ground level and how they would be attributed to “counties”, etc. This would take some time to sort out in addition to many other issues regarding how to run the various model(s) to compute the emissions.

thanks @eyth.alison .