It was a pleasure to read Jackson et al. (egusphere-2022-1171). Jackson et al. provide a comprehensive investigation of extreme conditions (snow accumulation rate and temperature) at Mt Brown South in East Antarctica and associated impact on water isotopes. Understanding the relationships between ice core water isotopes and climate over the re-analysis period is critical to interpret the ice core record from the Mount Brown South site. The age model for the sections of core used in this manuscript have previously been published (Crockart et al., 2021). This manuscript is particularly timely as the community is realising the importance of extremes on climate and thus the implications for paleoclimate records. The manuscript is engaging, well written and follows a logical structure. I recommend publication and hope the minor comments below are helpful in improving the manuscript.

Minor suggestions

• Why were 5-day back trajectories run and not 10 or 14-day back trajectories? Please justify and consider expanding to 10–14-day trajectories.
• Confusion over the relationship between blocking and winter EPE: L429-430 states no correlation between winter EPE and blocking while L746 states there is a weaker association between winter EPE and blocking. Which is it? It is interesting that the authors find a greater occurrence of extreme accumulation events during the winter but no/weak correlation between EPE accumulation and atmospheric blocking in winter. Please clarify the winter relationship and further explore the causes of the high occurrence of winter EPE.
• Please include the identification of atmospheric rivers in the methods section. Is MBS located in a region that typically experiences atmospheric rivers?
• Please discuss the variability of the MBS-C and MBS-main d18O records (Fig. 7a).

Specific comments

L45-48 Please add reference.

L52 and throughout Consider using the terminology enriched/depleted rather than heavy/light.

L64-65 Is this the same definition as EPE in Turner et al. (2019). Please clarify and add reference.

L83, L107 and throughout “Wille et al. (2021)” “Vance et al. (2016)”

L107 Please add location of this core.

L112 Note that the age model for the full core is still in development. Please update with a reference if this is now published.

L124 “...isotope record.”

L153 Delete “Only”. This is a substantial amount of work and criterial for the interpretation of the longer record.

L156-157 Please add the time resolution each sample covers.

L177 Please state what seasons these markers are assumed or known to occur in.

L182-184 Move last sentence in paragraph to first sentence in paragraph and then you can briefly state how the cores were dated by Crockart et al. (2021). Please add the dating uncertainty at the base of each core.

L259 Why 5-day back trajectories and not 10 or 14 day back trajectories?

L290-291 Please check significant figures here and throughout.

L293 RACMO2 slightly underestimates accumulation rates derived from the MBS core. How does this underestimation compare to other ice cores? e.g. Thomas et al. (2017)

Thomas, E. R., van Wessem, J. M., Roberts, J., Isaksson, E., Schlosser, E., Fudge, T. J., Vallelonga, P., Medley, B., Lenaerts, J., Bertler, N., van den Broeke, M. R., Dixon, D. A., Frezzotti, M., Stenni, B., Curran, M., and Ekaykin, A. A.: Regional Antarctic snow accumulation over the past 1000 years, Clim. Past, 13, 1491–1513, https://doi.org/10.5194/cp-13-1491-2017, 2017.

Figure 1 Please add insert to map showing the location of the cores.

Please find the report attached in the supplement,