Some minor corrections:

1. Please clarify in the abstract “During spring, which is characterized by long-range transport of anthropogenic aerosols in the Arctic, the GC underestimates the AOD in the vicinity of Alaska”. In comparison to what?
2. Introduction is well written and has a good flow to it. However, there is one incomplete line

Line 70 when you talk about “To address the recently posted…and compare it to.” Compare it to what? Please complete

1. It would be easier if you marked central arctic sea-ice region that you are interested in along with the AERONET sites in figure 1
2. Do the optical properties used in the GOES-Chem model vary with time? Studies have shown that temporal evolution of the aerosol size distribution in models closely resemble to observations.
3. Figure 2: Put Hornsund in the bottom and PEARL, OPAL and Thule on top (this gives the reader a consistency because these three sites are from CA side). Are the correlation numbers mentioned in each figure for spring and summer for all the years put together? PEARL and OPAL are close together, then why do they have different correlations of GC with AERONET and AEROSNOW? What factors do you think affect the GC simulations? Its important you mention somewhere how you derived the natural AOD (marked with white in Figure 2).
4. Figure 3: Please use the same symbols for AERONET and AEROSNOW as in Figure 2 for consistency.
5. Line 210: “Additionally, and on average, all three datasets show periods of haze episodes during the spring season”. Is it three or four? Its confusing because there are 4 sites mentioned in the paper
6. Line 215; “We attribute these differences can largely be attributed to the fact that GOES-Chem simulates AOD independent of meteorological conditions, cloud cover and the spatial…” . Please rewrite the first part of the sentence. Also in Section 2.2, it was mentioned that GC uses MERRA 2 reanalysis for meteorological fields but Line 215 contradicts this. Please clarify.
7. Line 225: “Further, during summer, the discrepancies in GOES-Chem AOD can be attributed to various factors, including limitations related to NPF and inherent effects of a relatively coarse horizontal model resolution”. In Line 215, it is mentioned that GC is independent of cloud cover. Arctic receives precipitation in summer and it is also possible, in addition to NPF and low res, that the GC doesn’t represent clouds well and because of which there are discrepancies mainly in summer!!
8. Line 234: In figure 4, we present the seasonal AOD for spring and summer, averaged over the entire study period. For each station, three circles are displayed” I think there are 4 circles displayed, so please correct this.
9. Line 270: there is a typo. Make it 2003 instead of 203.
10. Line 282: “GOES-Chem simulations showed higher and lower AOD during spring of the year 2009 and 2007 respectively”. Are there any reasons why only these particular years were chosen? 2004, 2006, 2008 also showed higher GC-derived AOD.
11. It is very interesting that this study talks about the lack of NPF in the models. During summer, the GC underestimates in some places and overestimates in others wrt AEROSNOW. And the authors say this could be due to lack of proper representation of NPF in model, which in my opinion, could be true but also I feel NPF is a common occurring in the Arctic summer. So if lack of NPF was the main issue, then it would have underestimated all throughout and not shown such discrepancies spatially! How can you explain why it overestimates AOD in some places? Lack of NPF cannot be the reason! When you measure AOD, do you also take into account cloud residuals?
12. This isn’t related to this study but I think we can see interesting results when AEROSNOW algorithm will be applied to study the aerosols during Arctic winters.