# Estimating PM2.5 emissions from BC/OC emission **URL:** \ **Category:** Emissions Inventory\ **Created:** [November 15, 2018, 1:18pm UTC](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emission/414 "2018-11-15T13:18:56Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![skunwar](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@skunwar](https://forum.cmascenter.org/u/skunwar)\ **Post date:** [November 15, 2018, 1:18pm UTC](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emission/414/1 "2018-11-15T13:18:56Z")
> [@Estimating PM2.5 emissions from BC/OC emissions](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emissions/412): > > A) If the emission inventory only has BC and OC emissions, how do you estimate the PM2.5 and PM10 primary emissions from BC/OC emissions to feed to SMOKE for emissions processing? B) Related question: If aircraft emissions data only have BC emissions, how do you estimate the PM2.5 and PM10 primary emissions from the BC emission to feed to SMOKE for emissions processing? ---
**Author:** ![eyth.alison](https://avatars.discourse-cdn.com/v4/letter/e/7ab992/32.png) [@eyth.alison](https://forum.cmascenter.org/u/eyth.alison)\ **Post date:** [November 15, 2018, 6:17pm UTC](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emission/414/2 "2018-11-15T18:17:13Z")
Hi, ![](https://canada1.discourse-cdn.com/flex027/uploads/cmas/original/1X/64f616983d5e1c5697da3e3dc3eb37d7d031eebf.jpeg) ![](https://canada1.discourse-cdn.com/flex027/uploads/cmas/original/1X/8098cb7db4f9c0067c71d0d9b19d51b457c1801b.jpeg) ---
**Author:** ![skunwar](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@skunwar](https://forum.cmascenter.org/u/skunwar)\ **Post date:** [November 16, 2018, 2:56am UTC](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emission/414/3 "2018-11-16T02:56:23Z")
It seems a reply might have been intended here? ---
**Author:** ![eyth.alison](https://avatars.discourse-cdn.com/v4/letter/e/7ab992/32.png) [@eyth.alison](https://forum.cmascenter.org/u/eyth.alison)\ **Post date:** [November 16, 2018, 12:52pm UTC](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emission/414/4 "2018-11-16T12:52:49Z")
Trying again: ![](https://canada1.discourse-cdn.com/flex027/uploads/cmas/original/1X/64f616983d5e1c5697da3e3dc3eb37d7d031eebf.jpeg) ---
**Author:** ![skunwar](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@skunwar](https://forum.cmascenter.org/u/skunwar)\ **Post date:** [November 16, 2018, 3:40pm UTC](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emission/414/5 "2018-11-16T15:40:10Z")
Still does not show anything except ‘Trying again:’ Did you intend to share a link or an image? ---
**Author:** ![eyth.alison](https://avatars.discourse-cdn.com/v4/letter/e/7ab992/32.png) [@eyth.alison](https://forum.cmascenter.org/u/eyth.alison)\ **Post date:** [November 16, 2018, 4:11pm UTC](https://forum.cmascenter.org/t/estimating-pm2-5-emissions-from-bc-oc-emission/414/6 "2018-11-16T16:11:00Z")
I guess it is picky about any formatted text. This should be plain text: (1) SMOKE does not need PM2.5 - BC and OC can be modeled in SMOKE as individual inventory species. However, most of the modeling platform files however have been created assuming PM2.5 is available so there would need to be some modifications to the INVTABLE and perhaps other files. (2) You could consider summing BC + OC to make PM2.5 and leave the other components as zero and also update the speciation profiles to account for this change. Note that this would require updates to the modeling platform files specifically the gspro. Ultimately, it depends on the modeling application. If the remaining components of PM2.5 are needed (NO3, SO4, and the various metals and crustal components), then an estimate for these would be required. If the modeling application is for ozone, option (1) would be sufficient. ![](https://canada1.discourse-cdn.com/flex027/uploads/cmas/original/1X/64f616983d5e1c5697da3e3dc3eb37d7d031eebf.jpeg)