|The paper 'Evaluation of the MACC operational forecast system' has improved a lot since the last revision and I recommend it to be published subject to minor changes, mostly technical. There still remain some small questions, though, (points 13, 14, 25, 26, 27 below) that need to be answered:|
1. Acronyms should be defined where they appear first, also in the abstract (e.g. SCIAMACHY, GOME, MOPITT, EU, MOZART, TM5, OASIS4, MLS, SBUV, OMI, IASI, MODIS, GEIA, FFED, GFAS, MEGAN, B3dCTM, FRESCO... I have certainly missed some, do a search for the first appearance).
2. page 3, line 2: replace 'and environment' with 'and the environment' (add a definite article).
3. page 3, line 4: remove the full stop and continue with lower case 'as'
4. page 3, line 10: replace 'and crop yields' with 'as well as crop yields'.
5. page 3, line 16: MACC has already been defined, delete the definition here.
6. page 3, line 18: CAMS also has been defined already, delete the definition.
7. page 5, lines 12 and 18: once your write 100 km x 100 km and another time 80 km, be consistent.
8. page 5, lines 13 and 19: once you write MOZART-3 another time MOZART version 3.5, be consistent.
9. page 5, line 24: replace 'out of the EU project' with 'from the EU project'.
10. page 7, line 18: it would be good to have an indication which stations provide CO and which O3 in table 3
11. page 7, line 19: full stop after O3 is in subscript.
12. page 7, line 20: replace 'the data in the database is' with 'the data in the database are'
13. page 7, line 29 and page 8, line 17: Motivate why for GAW 6 hourly model data are used and for EMEP 3 hourly model data and why the day night difference is only done for the EMEP data (e.g. 'We only used this data set to test the dependency of the biases on day and night data' or something like that).
14. page 8, line 1: What is the maximum altitude difference between the station and the model level, it would be good to know this.
15. page 9, line 8: replace 'In order for better data quality' with 'In order to achieve better data quality' or 'In order to get...' or something like this.
16. page 9, line 19: If with the sentence 'The model CO total columns used in the comparison with MOPITT observations, have been calculated using the averaging kernel smoothed profiles X* which have the same vertical resolution and a priori dependence as the MOPITT retrievals.' you mean 'The averaging kernel smoothed CO data X* have the same vertical resolution and a priori dependence as the MOPITT retrievals. These have been used to calculate averaging kernel smoothed model CO total columns which are compared to the MOPITT total columns.' then you should replace it. As it stands it is not clear.
17. page 10, line 17: 'Satellite observations are gridded to the horizontal model resolution'. Do you mean 'Satellite observations are interpolated to the resolution of the horizontal model grid.'
18. page 10, line 29: explain why Siberia and Alaska are excepted.
19. page 11, line 20: symbols are all superscripted they should be set down.
20. page 12, line 15: replace 'below' with 'bottom' (also in the Figure)
21. page 12, line 24: maybe better 'appears to be remedied' instead of 'has been' or put a reference for a validation for this.
22. page 13, line 32 and page 14, line 1: -9 is not a positive bias, please rephrase.
23. page 14, line 11: the 'larger' refers to larger negative and larger positive biases, please clarify.
24. page 14, line 29: Are the monthly MNMBs global? Please indicate if so.
25. page 28, line 28: I presume you don't use AK smoothed IASI data to compare with MOPITT data, as you did for the MACC comparisons. Depending on what you compare this discussion is not valid, since the AK smoothing should get rid of the a priori information (in the MACC-MOPITT comparison but might not in the IASI-MOPITT comparison). With the ingestion of the IASI CO into the model, the model sees CO as IASI does. Depending on the shape of the IASI AK you might need to smooth the MOPITT data... Please check!
26. page 18, line 7: Is this likely because of more stations in the North?
27. page 18, line 9: Just looking at the data, could the biases not also come from a temperature dependency?
28. page 18, line 15: please replace 'the new model cycle and MOZART model version' with 'the new model cycle and the new MOZART model version'.
29. page 19, line 5: Please replace 'There is a close agreement' with 'There is close agreement'
30. page 19, line 9: Please replace 'are at a highest' with 'are highest'
31. page 21, line 6: Replace 'emissions.Inc nsistencies' with 'emissions. inconsistencies.
32. page 21, line 8: Should there not be a 'forecast' or 'assimilation' after NRT?