Hi,
I am using the EPA SMOKE 2016v2 platform to generate emissions for my domain in Victoria, BC. While running the model for commercial marine vessels, I observed some emissions occurring inland, which is not expected.
Upon investigation of the shapefiles, I identified that the issue is related to the projection. It seems that the projection is causing some marine emissions to be incorrectly allocated to land. Does anyone have insight into how to address this issue?
Which grid are you preparing emissions for and which air quality model are you running?
@eyth.alison
I am using customized grid setting for my project. I have three grid resolutions of 1, 3, and 9 km. However, I am getting inland emissions in both of my 3km and 1km domains.
my air quality model is CMAQ.
my GRIDDESC is below:
’ ’
‘LamCon-UTSTAND’
2 30.000 45.000 -97.000 -97.000 49.000
’ ’
‘bc_d01’
‘LamCon-UTSTAND’ -2183500.000 -23500.000 9000.000 9000.000 64 64 1
’ ’
‘bc_d02’
‘LamCon-UTSTAND’ -2009500.000 159500.000 3000.000 3000.000 64 64 1
’ ’
‘bc_d03’
‘LamCon-UTSTAND’ -1984500.000 193500.000 1000.000 1000.000 58 58 1
’ ’
Starting with the 2016 platform and 2017NEI, commercial marine vessel inventories have release points at the centroid of the grid cell on a specific gridded modeling domain. Commercial marine inventories on the 12US1 12 km domain and 36US1 36 km domain were provided for the 2016v2 platform. Along coastlines it is common for a 12 km or 36 km grid cell to have less than half of its area over water, which tends to lead to the centroid/release point being placed on land. If that 12 km or 36 km inventory is used for finescale modeling then that release point can appear in a grid cell entirely over land. This effect explains at least part of the overland emissions that you are seeing when putting these release points developed for a 12 km inventory on 3 km and 1 km grids.
I can suggest some work-arounds. Could you please share which sectors you are seeing this issue in (cmv_c1c2 and/or cmv_c3) and the magnitude of the emissions over land at your target resolution?
@james.beidler Thanks for providing the details on what caused the problem.
This definition helped a lot. I could solve my issue.
Thanks.
