the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 19 Jun 2025
Snow accumulation rates at Concordia Station, Antarctica, observed by stake farms
Abstract. In this study, surface mass balance (SMB) is estimated from snow accumulation data collected in the nearby area of Concordia Station, Antarctica. Results from the Italian and French stake farms are jointly analysed. The Italian stake farm is located ~800 m southwest of Concordia Station and consists of 13 stakes; continuous observations started at the end of 2010 with near-monthly sampling. Some measurements are also available for the 2006–2010 period from a previous stake farm which was located ~500 m south-southwest of the Station, i.e., ~300 m east of the current site. The French stake farm is located ~2 km south of the base and consists of 50 stakes; observations started in 2004 with yearly sampling during austral summer. Snow build-up measurements at individual stakes show a strong variability caused by the interaction of wind-driven snow with surface micro-relief. In the common observation period, the present Italian stake farm generally underestimates the SMB with respect to the French one, except for three years in which an overestimation is observed. Over the 2011–2023 period, the mean yearly accumulation recorded by the Italian and French stake farms is 7.3±0.2 cm and 8.4±0.1 cm, respectively. Bootstrap simulation has been performed to: (i) assess the significance of the differences between the two datasets; (ii) evaluate the effect on the measurements of the different size of the stake farms and their distance to the Station. The comparison of the observations with reanalysis datasets (ERA5 and MERRA2) and regional models (RACMO2.4p1, MAR3.12) indicates the former more in agreement with the observations. The potential interaction effect of the Station has also been investigated by analysing wind direction during snowfall events, suggesting that buildings may influence accumulation when they are upwind with respect to the stake farms. Additionally, two more stake farms, located 25 km north and south of Concordia Station, are also analysed to study the SMB gradient across Dome C, confirming previous results. On average, yearly SMB increases northward by 8–9 % over the 50 km span between the southern and northern stake farms. At Concordia, for the 2004–2023 period, a mean SMB of 27.21±0.60 kg m–2 has been estimated, taking into account the uncertainty of the observations and of the snow compaction effect. Results are valuable for validating SMB estimated from reanalysis, regional climate models and remote-sensing data.
- Preprint
(4252 KB) - Metadata XML
-
Supplement
(359 KB) - BibTeX
- EndNote
Status: final response (author comments only)
-
CC1: 'Comment on egusphere-2025-2477', Alexey Ekaykin, 25 Jun 2025
Dear Claudio, congratulations with this manuscript, it is brilliant!
I have a couple of comments, see below:
Section 2.1, Italian stake farms: as I can see from the text, the size of the farms is something like 60 by 70 m. If so, the farms are comparable in size with the largest snow dunes traveling across the snow surface. This fact can add the noise to the inter-annual ITA SMB time-series, which may explain a larger inter-annual variability at ITA farms (Fig. 5).
Then, the distance between stakes at these farms is 10 m which is close to the distance of noise correlation. It means that the observation at a single stake is not independent from the adjacent stakes, and the effective number of datapoints is < 13.
Taking this into account, and also considering the information in Section 4.3 (the farms are too close to the Station?), is it better not to use the ITA data in further analyses?
Also a few small ones:
Line 46 - “SMB is a small difference between large fluxes». I am not sure what you mean here exactly. SMB is (in a first approximation) a difference between precipitation and sublimation, the latter being relatively small fraction (like 10-20 %) of the first. It is the total Antarctic ice sheet mass balance which is a small difference of two huge fluxes, total snow accumulation (SMB integrated over the area) and ice ablation on the AIS’s edges.
Lines 54-56 – here you describe how we make a correction for snow compaction at Vostok, but this paragraph is about defining the density of an annual layer in order to calculate SMB in water equivalent. For this we measure the mean density in the upper 20 cm of snow thickness in a number of random points across the stake farm.
Line 72 – I cannot find Vandecrux et al., 2024 in the reference list.
Line 109 – as I can see in Figure 1b, the length of each farm’s profile is about 1 km, 25 stakes in each profile. It means an average distance between stakes is 40 m, not 25 m.
Lines 175-176 — it is better to say that each snow layer within this thickness is compressed under the weight of the overlying snow.
Tables 2 and 4 – there are negative values in the lower limits of the confidence intervals of the compaction corrections which is not possible physically. Probably it’s better to set forcibly the lower limits to zero?
Very best regards,
Alexey Ekaykin
Citation: https://doi.org/10.5194/egusphere-2025-2477-CC1 - AC1: 'Reply on CC1', Claudio Stefanini, 16 Jul 2025
-
RC1: 'Comment on egusphere-2025-2477', Anonymous Referee #1, 17 Jul 2025
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2025/egusphere-2025-2477/egusphere-2025-2477-RC1-supplement.pdf
- AC2: 'Reply on RC1', Claudio Stefanini, 03 Sep 2025
-
RC2: 'Comment on egusphere-2025-2477', T. Kameda, 25 Jul 2025
Title: Snow accumulation rates at Concordia Station, Antarctica, observed by stake farms
Author(s): Claudio Stefanini and others
General comments
This manuscript presents scientific data on snow accumulation at Concordia Station, Antarctica, collected by stake farms from 2004 to 2024. They reveal the SMB at the site, which is new data. Therefore, this manuscript is worthy of publication. However, I found several issues in this manuscript.
Specific comments
1. Snow density for SMB calculations, Lines 53−56 and Line 178
Two densities are introduced to calculate the SMB from stake data in previous studies: upper 2 m by Takahashi et al. (1994) and surface to the bottom of the annual snow layer by Kameda et al. (1997) and Satow et al. (1999) in Lines 53–55.
As briefly described in Line 178, Takahashi and Kameda (2007) first propose that the appropriate snow density for SMB from stake data is the mean snow density at the stake base during the snow stake measurement period, which is the snow density for SMB considering snow compaction. Kameda et al. (2008) used the density for SMB calculations at Dome Fuji. Thus, it is better to add Takahashi and Kameda (2007) and Kameda et al. (2008) at Line 54, immediately preceding Ekaykin et al. (2020).
2. Lines 156–157
The first paper to consider snow density in relation to snow compaction during stake measurements is Takahashi and Kameda (2007). Thus, after line 157, it would be better to add this paper for reference.
3. Line 163
I think “hundreds of meters” from the surface is ice, not snow. I think the deepest snow (permeable material) at Dome C is around 100 m, not “hundreds of meters”.
4. Line 178
Takahashi et al (2007) -> Takahashi and Kameda (2007)
5. SMB (cm) in Fig. 4, 5, 7a, 7b, 8
The y-axes of these figures are SMB (cm). Is it a water equivalent value or a snow equivalent value?
To eliminate misunderstandings, the term “surface mass balance (SMB)” is often used in previous papers. The unit of SMB is kg m-2 a-1. If you use the unit in the y-axis in these figures, it is clear that the value is the same as mm in water equivalent.
6. Line 260
What is +26.6 %%? I think a "%" should be omitted.
7. Line 240.
Is the p-value of 0.40 correct?
8. Line 378
I think “erosion” is a more appropriate term than “ablation”, because there is no water at Dome C even in the summer season.
9. Line 379
Kameda et al. (2008) used “the negative and zero SMB” for expressing the condition. Please consider using this term to express the same phenomenon.
10. Lines 384–387
It is better to add figures to express the relation described in the text.
11. Line 399
Fujii and Kusunoki (1982) and Takahashi et al (1992) will be good references for sublimation at the snow surface at the Antarctic ice sheet.
Please consider to add these papers for reference.
Fujii, Y., and K. Kusunoki (1982), The role of sublimation and condensation in the formation of ice sheet surface at Mizuho Station, Antarctica,
J. Geophys. Res., 87(C6), 4293–4300, doi:10.1029/JC087iC06p04293.
Takahashi, S. Endoh, T., Azuma, N. and Meshida, S (1992): Bare ice fields developed in the inland part of the Antarctica. Proc. NIPR Symp.
Polar Meteorology and Glaciology, 5, 128-139.
Best regards,
Takao Kameda
Citation: https://doi.org/10.5194/egusphere-2025-2477-RC2 - AC3: 'Reply on RC2', Claudio Stefanini, 03 Sep 2025
-
RC3: 'Comment on egusphere-2025-2477', Anonymous Referee #3, 28 Jul 2025
This paper deals with snow accumulation data provided by several stake farms distributed around Dome C. This is probably one of the sites located in the inner East Antarctic Ice Sheet which is most studied from this point of view. With many data available from ice cores, geophysical prospecting, and previous studies on stake farms. From this point of view the site is thus extremely important in the field of Inner Antarctica snow accumulation estimation.
The authors present new data returned from novel stake farms that have been monitored in the last years. The core of the study is the comparison between these new farms and previous ones, including a comparison with data derived from reanalyses and models.
Notable discrepancies are noted among the different farms which cannot be related to the well-known precipitation gradient that characterizes the Dome C area. Several hypotheses are made to explain such differences and in the end the explanation provided by the author is that several processes are responsible for the variability observed in the data. The existence of the cited gradient, the different size of the farms (with impacts on uncertainties and variability of annual data), the effect of buildings on snow accumulation/erosion.
In general the paper is well written, it is scientifically solid and the data are carefully analyzed and interpreted. I would probably suggest to deepen a little bit the part where reanalyses -derived data are described. Considering the peculiar features of the site, it is not clear how the authors calculated snow deposition, erosion, sublimation using reanalyses data. Please provide more information on this.
My second concern, which is the most notable one, is about the general “story” behind the manuscript. The current title is “Snow accumulation rates at Concordia Station, Antarctica, observed by stake farms”. Reading this title and the general structure of the paper, in particular the introduction, one can think that the key message of the present work is to provide new estimate for snow annual accumulation for an important site of inner East Antarctica. This is only partially true in my opinion. The main argument of this work is to discuss in details the parameters which can influence the estimation of snow accumulation using multiple stake farms distributed around a single site. This is now not clear, in particular if a reader only focuses on the title/abstract and introduction. I suggest to the author to change a bit these key elements of the manuscript, focusing more on the parameters which introduce variability in data gathered from stake farms. Adopting a title like “On the factors which influence the estimation of snow accumulation rates at a site in inner East Antarctica: lessons learned at Dome C”, would surely help the readers to understand what they will find in this nice and detailed manuscript. Of course changing the title and in general the “scientific narrative”, it would be needed to change also some other parts of the manuscript, in particular the introduction.
Line 15-20: I don’t think it is necessary to provide such detailed information about the stake farm position in the abstract. There is the materials section for this. I would just say that in this work you are going to compare results from the different available farms around Dome C, providing some basic data about the temporal interval which is considered here.
Line 35: “for understanding”?
Thanks for your attention
Citation: https://doi.org/10.5194/egusphere-2025-2477-RC3 - AC4: 'Reply on RC3', Claudio Stefanini, 03 Sep 2025
Viewed
| HTML | XML | Total | Supplement | BibTeX | EndNote | |
|---|---|---|---|---|---|---|
| 460 | 91 | 24 | 575 | 21 | 12 | 24 |
- HTML: 460
- PDF: 91
- XML: 24
- Total: 575
- Supplement: 21
- BibTeX: 12
- EndNote: 24
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1