In this study Nilsson et al. investigate the cohesion between the weather variability and precipitation rates in the 20^th Century Reanalysis v3 (20CRv3) compared to the accumulation at the Dome Summit South (DSS) drill site, Law Dome. The sparse observational data makes it challenging to constrain reanalysis products for this region and the authors use self-organizing maps to produce weather patterns and find the patterns which are correlated with reanalysis precipitation at DSS. Nilsson et al. then compares the weather patterns and reanalysis precipitation with the annual accumulation rates from the DSS ice core. The main conclusion is the 20CRv3 performs very well after 1948 when an adequate amount of data is entering the reanalysis. The authors go on to suggest guidelines for comparing reanalysis products with Antarctic ice core data and how to improve the reanalysis data in regions with sparse observations.

General comments.

Overall, I find this study to be interesting and relevant, and the results and conclusions contribute to an area which is sort of a white spot on the map. The science question is clear and analysis, as well as, figures, data and method description are generally well executed.

There are, however, a bit of work to be done before the manuscript is fully publishable. I have quite a few comments regarding clarity and readability, and not the least structure of the manuscript. I find that there is a lot of mixing of the results and discussion section, and basically the results section should be longer and the discussion shorter. All of the description and explanation connected to Figure 4, 5 and 6, as wells as, Table 3 should be in the results section. See also detailed comments below regarding this. Furthermore, I think writing in present tense when describing analysis done in the paper is more appropriate. Historical facts and events can be referred to in past tense.

I do wonder if a seasonal signal can be extracted from the ice core given the high accumulation rate, and the availability of high-resolution isotope and impurity data. This could give further insights to the seasonal variability of weather patterns in the region and also regarding seasonal trends in accumulation. Maybe a point for the discussion?

Detailed comments.

L12 “with increased precipitation” and I suppose thus also decreased precipitation. Suggestion: “variability of precipitation amount”

L24 “These weather systems have changed in frequency over the satellite era “. Suggestion: “The occurrence of these weather systems have changed in frequency over the satellite era “.

L30 “satellite era, and include” suggestion: “satellite era. The most recent reanalysis products include”.

L34-35 “These reanalyses are generally considered to perform poorly “ a reference or two to support this would be in order.

L75 Add “Dome Summit South” before DSS.

L77 “0.69 metres ice equivalent from frequent cyclonic incursions ” I suggest to make a full stop before from and explain about the processes forming the precipitation in the next sentence.

L77 “annual accumulation rate of 0.69 metres ice equivalent ” I found no description how the accumulation is converted to ice equivalent. How is firnification and ice flow treated? Also, is evaporation and issue when comparing accumulation and reanalysis precipitation? I didn’t found any mention of this. Maybe not an issue for Law Dome, but for other sites with low accumulation. Could be a point in the discussion.

L77-78 “produces seasonally varying annual layers ” how can annual layers be seasonally varying? Please rephrase.

L79 “Annual layers are identified ” is this done in this study or in the studies you refer to?

L80 “and validated against known volcanic eruptions ” It’s the time scale i.e., dating, which is validated using volcanic eruptions as tie points.

L93 “applied to weather and climate applications ” I think it should be “applied in”, but maybe better to reformulate and avoid using both “applied” and “applications”.

L104-105 Maybe the correlations “can be expected” to be lower?

L107 “associated with increased precipitation at Law Dome ” if you get which patters give increased precipitation, you also get the patterns that cause low precipitation. I think it is more intuitive to generally formulate that you want to establish the relation between the SOM patterns and precipitation amount at Law Dome.

L112 Some kind of introducing part of the sentence should be added here so that one understands it’s a new topic. Something like “We then calculated” “In a next step”…

Table 1: The standard would be to have two significant digits for correlation and explained variance. And keep it consistent between text and table. It says “r = 0.8” in the text L144.

L145 For trends upper and confidence bounds can be more instructive than a p-value.

Section 3.2: All but the last sentence of this section starts with “the” which makes it very repetitive. Consider rewriting with more flow by adding a few words where it fits, e.g. ”Similar to” “In contrast with”.

Figure 2: Unit for accumulation in caption “miceequivalent”. Mice equivalent? I think making the DSS accumulation as a stair-type plot would improve the readability of the graph.

Figure 3: You could add the DSS site in the figure so the reader has something to hang onto.

L192-193 “Synoptic types 3, 4, 8 and 12 were associated with high precipitation at Law Dome ” this is a central result. Add some text to explain why these weather patterns result in high precipitation att DSS and others not. You explain this in Section 4.2 but I think this is part of the results.

L193: Fig. 5 is referred to before Fig 4. Check so that all figures are ordered in the same way they appear in the text.

L202: Discussion. I my mind the discussion cannot start here. You are not done describing your results. You are allowed to discuss things while describing your results in the extent they are need to explain things.  For example, you can say that your results depend on the number of observations going into the reanalysis, given the topic of your study there is nothing controversial about that. In your discussion you write about uncertainties, relation to other studies, add minor results that might frame your main results and finally an outlook for future studies or recommendations.

Figure 6: Use 2 significant digits for R^2 in figure.

L211 “that have been assimilated into ISPDv4.7 increase from” something wrong in this sentence.

L216 Byrd station also established in 1957. Although not in East Antarctica this also helps constrain the large-scale circulation around Antarctica.

L224-241 Keep this in discussion.

Section 4.2 is mainly results.

L271-274 Results.

L274-281 This is mainly Discussion. You might note that blowing snow is less of an issue at high-accumulation sites.

L281-293 Results.

L293-301 Discussion.

Please see the attachment.