Dear Authors,

I found that the manuscript was revised successfully, by taking the comments from the two reviewers into account. I would request minor revision/discussion on the following points.

1. The original comment made by the reviewer #1 as follows aims to integrate "satellite AMFs" into account, not "MAX-DOAS averaging kernels". However, the authors’ rejected this comment based on the unavailability of the “MAX-DOAS averaging kernels". The reply needs to be revised.
Page 21, lines 646-648: Since satellite total HCHO AMFs and averaging kernels are missing in the files, you could proceed the other way round for eliminating the difference caused by the non-representative satellite a priori HCHO profiles, i.e. recalculating satellite AMFs using MAX-DOAS vertical profiles and dividing the satellite slant column densities by those new AMFs (see e.g. De Smedt et al., Atmos. Chem. Phys., 15, 12519–12545, 2015). Maybe something worth to try.

2. Another original comment made by the reviewer #1 as follows implicitly aimed comparison between the converted MODIS AOD at 360 nm with that of MAX-DOAS. Some comments are needed on this point.
Page 50, Figure D4: How MODIS would compare to the AERONET sun photometer measurements at these two sites? Angstrom exponent could be used to convert MODIS AOD from 470 nm to 360 nm.

3. Replies to the reviewer #2 and the relevant revisions are mostly reasonable, particularly for making focused scientific points, regarding 1) source/process analysis on the seasonal and diurnal trends of AOD, NO2, and HCHO, 2) analysis of BLH and deep convection, and also regarding 3) O3 production regimes in the morning and late afternoon hours. Also, I believe that the point that this study provides the first evaluation of three OMI NO2 data products and two OMI HCHO data products over the IGP is strong.

4. Lines 1395-1396 of the change-track version. I would suspect that information from lower elevation angles than 30 degrees are equally important when deriving VCD. The aerosol information from the O4 analysis would be most worth when systematic difference between NO2 VCDs between satellites and MAX-DOAS is analyzed. I believe this was the main point that the reviewer #1 made with the relevant comment.

5. Lines 1488 of the change-track version: Schofield et al. (2006) must be Schroeder et al. (2017).

Yugo Kanaya, Co-Editor of ACP

Dear Authors,
My points were studied in detail and the manuscript was revised accordingly. I now judge that the current manuscript is to be accepted.
Best regards,
Yugo Kanaya, Co-editor of ACP