Beginner questions about inputs, scenarios, and basic use

[Natalia Gonzalez]

I am new to InMAP, so please forgive me if my questions are elementary.

1. I want to evaluate only the WECC (i.e. Western Interconnection). Is it possible to only evaluate a subset of the U.S. or do I need to run the whole U.S.?
2. It seems that InMAP draws its own “baseline” from the 2005 emissions inputs. If I wanted my baseline to be a hypothetical scenario with close to 0 emissions in the electricity sector, what would I need to change so that the delta in emissions that gets outputted is calculated with respect to this custom baseline?
   • Related follow up question: Is it possible to specify emissions by sector? I want to keep all other emissions default, but only edit the emissions of the electricity generation sector.
3. I am running scenarios based on a 2035 study. That being said, what are the implications of the default input files? Using the default emissions from 2005, census data from 2011-2015, mortality rates from 2013, it seems that the assumption would be that all those values remain constant between those mentioned years and 2035. The inconsistency in years is also confusing. 
4. When InMAP says tons/year, is that metric tons (tonnes) or U.S. tons?

Thank you in advance to anyone that can help!

[Chris Tessum]

Hi Natalia,

Welcome. Here are some answers:

1. I want to evaluate only the WECC (i.e. Western Interconnection). Is it possible to only evaluate a subset of the U.S. or do I need to run the whole U.S.? You can evaluate a subset of the US, but it is probably easier to just do the whole US.
2. It seems that InMAP draws its own “baseline” from the 2005 emissions inputs. If I wanted my baseline to be a hypothetical scenario with close to 0 emissions in the electricity sector, what would I need to change so that the delta in emissions that gets outputted is calculated with respect to this custom baseline? InMAP is a linear model with respect to emissions amount, which makes the baseline less important. Basically the emissions you input can just your emissions delta, you don't have to worry about the baseline.
   • Related follow up question: Is it possible to specify emissions by sector? I want to keep all other emissions default, but only edit the emissions of the electricity generation sector. Sure, but for any scenario you run, you need the corresponding emissions data. There is some emissions data that might ber useful here: https://zenodo.org/records/5831940
3. I am running scenarios based on a 2035 study. That being said, what are the implications of the default input files? Using the default emissions from 2005, census data from 2011-2015, mortality rates from 2013, it seems that the assumption would be that all those values remain constant between those mentioned years and 2035. The inconsistency in years is also confusing. You're welcome (encouraged!) to update any of those. In particular the 2005 emissions wouldn't be considered relevant any more. In general, even though we provide default or example data, that shouldn't be taken as a statement that the default data is appropriate for a given analysis.
4. When InMAP says tons/year, is that metric tons (tonnes) or U.S. tons? "Tons" is U.S. short tons, "tonnes" is metric tonnes. We've tried to be consistent about that throughout the documentation etc., but let us know if something seems wrong.

[Natalia Gonzalez]

Hi Chris,

Thank you so much for your replies. As a follow up to the first question, how would I analyze just a subset of the U.S.? In other words, what files would I need to modify? It is important to our study that we look at the WECC only

[Chris Tessum]

You would need to update the grid information in the configuration file and then re-generate the gridded data file. Some information about the configuration file is here. But overall it might be easier to run the model for the whole US and then do a post-processing step to ignore everything outside of your area of interest, especially if your area of interest is not a rectangle.

[Natalia Gonzalez]

Hi Chris,

I had a couple follow up questions come up. 

1. (follow up from Q2 above) If InMAP takes my emissions delta as an input, what happens when some counties experience an increase in emissions and some experience a decrease? Is it possible to include "negative emissions" in the calculation? I am trying to compare one case to a baseline case.

2. Is it possible to input emissions with different spatial resolutions? For example, some point sources, some county-wide emissions, some emissions from zones with custom shapes?

[Natalia Gonzalez]

Just following up on this. If anyone has any insight, please let me know!

[Anil Gogebakan]

Hi Natalia,

1. Technically, it is possible to feed negative and positive emissions to input InMAP calculations as I have done something similar recently. I believe it does whatever it is supposed to do, but I did not give it a deep thought and am not 100% sure that it does not "misbehave" when it uses "negative" numbers as input.

2. I haven't done this but I believe it should be possible as long as you identify geometric coordinates as you like in your emissions input data file. If it is county you can put the coordinates of the county (not sure how to specify the coordinates), if it is a point source you can use the geometry coordinates accordingly. Alternatively, you could just calculate different resolutions differently and combine the output, but this may be problematic as I believe atmospheric chemistry calculations behind InMAP are non-linear (I could be wrong). I would try something like the former suggestion I had.

Good luck,

Anil G.

[Chris Tessum]

Also here is some information about the emissions: https://inmap.run/docs/emissions/#:~:text=Within%20the%20shapefiles%2C%20emissions%20can%20be%20expressed%20as%20point%2C%20line%2C%20or%20polygon%20geometries