Dear authors,

Thank you for submitting a revised manuscript entitled “Evaluating a fire smoke simulation algorithm in the National Air Quality Forecast Capability (NAQFC) by using multiple observation data sets during the Southeast Nexus (SENEX) field campaign”.

Having read the revised manuscript and your comments to the reviewers, I am pleased to say that I thought that the writing had improved since the submitted manuscript, making it much clearer to both follow and understand. However, as you’ll see from my list of specific comments, there still remains a large number of either poorly constructed sentences or grammatical errors. May I please ask that you correct these before the paper can be accepted for publication?

Regards,
Fiona O’Connor

Specific comments:
1. Line 229: Change “A detail of how model” to “Details on how the model”
2. Line 230: Change “follow” to “following”
3. Line 244: Give full names for NO3- and SO42- before using
4. Line 254: Replace “sea salts” with “sea salt”
5. Line 256: Replace “in model simulation” with “in the “with fire” model simulation”
6. Line 258: Give full name for “SSW” before use
7. Line 259: Replace “in MACA” with “at MACA”
8. Line 265: Remove “The model missed fire signal on July 3 at MACA.” due to duplication.
9. Line 277 and 278: Replace “represents area” with “represents the area”
10. Line 288: Remove “in terms of resulting” from sentence
11. Line 289: Replace “missed fire emissions” with “missed the fire emissions”
12. Line 293: Replace “in corresponding” with “in the corresponding”
13. Line 300: The whole sentence “The primary reason is that the HYSPLIT smoke simulation is accessed at the invocation of a forecast cycle the HMS fire information which is already one day old due to retrieval latency and cycle-queuing issues” needs re-writing to make clearer.
14. Line 303: Update “Huang et al. 2019 (manuscript in preparation).”
15. Line 304: Replace “despite both the HYSPLIT and CMAQ fire plume rise were estimated by the Briggs’ equation” with “although the HYSPLIT and CMAQ fire plume rise were both estimated by the Briggs’ equation”
16. Line 306: Replace “at daytime” with “during daytime”
17. Line 318: Replace “ASDTA is originally generate to provide operational support for verification of the NOAA HYSPLIT dispersion model predicts smoke plume direction and extension” with “ASDTA, originally generated to provide operational support for verification of the NOAA HYSPLIT dispersion model, predicts smoke plume direction and extension”
18. Line 337: Replace “in observation” with “in the observations”
19. Line 340: Change “Differences were attributable to:” to “Differences were attributable to a number of reasons: ”
20. Line 357: Change “evaluations” to “evaluation” and change “wind field” to “wind fields”
21. Line 360: Change “An additional uncertainty arose in the difference of temporal resolutions” to “An additional uncertainty arose due to the difference in temporal resolution”
22. Line 363; Change “flight transects” to “a flight transect”
23. Line 365: Change “color of flight path” to “color along the flight path”
24. Line 366: Change “from the surface” to “from surface”
25. Line 370: Change “Model simulation” to “The model simulation”
26. Line370: Change “long range transports” to “long range transport”
27. Line 372: Change “observation” to “concentrations”
28. Line 373: Change “or smoke plume around” to “or smoke plumes around”
29. Line 382: Change “all of evaluation” to “all of the evaluation”
30. Line 383: Change “reproduce fire” to “reproduce the fire”
31. Line 389: Change “concentration” to “concentrations”
32. Line 403: Change “Fire signals showed substantial influences on aircraft measurement” to “Fire signals have a substantial influence on the aircraft measurements”
33. Line 411: Change “were” to “are”
34. Line 413: Change “with CH3CN measured concentration above 400 ppt” to “with observed CH3CN concentrations above 400 ppt”
35. Line 418: Change “Other explanation was from Fig. 11b, which illustrated hotspots in hmx.txt.” to “Another explanation can be seen from Fig. 11b, which illustrates hotspots in hmx.txt.”
36. Line 420: Change “spots by HMS before quality control were showed” to “spot by HMS before quality control are shown”
37. Line 420: Change “there were clusters” to “there are clusters”
38. Line 422: Change “In most of time” to “In most cases”
39. Line 424: Change “For this case, there seem to have been thin clouds overhead and thicker clouds in the vicinity“ to “For this particular case, there seem to have been thin clouds overhead and thicker clouds in the vicinity“
40. Line 427: Please add a full stop at the end of the sentence
41. Line 436: Change “For IMPROVE data” to “For the IMPROVE data”
42. Line 438: Change “by CMAQ” to “by the CMAQ”
43. Line 440: Change “overlapping” to “overlap”
44. Line 451: Change “inflows” to “inflow”
45. Line 622: Change “shown along flight transect” to “shown along a flight transect”
46. Line 644: Change “highlighted” to “highlight”
47. Line 651: Change “a backward trajectory analysis for CH3CN concentration in ppt greater” to “A backward trajectory analysis for CH3CN concentrations greater”