NALPS19: sub-orbital-scale climate variability recorded in northern Alpine speleothems during the last glacial period

Moseley, Gina E.; Spötl, Christoph; Brandstätter, Susanne; Erhardt, Tobias; Luetscher, Marc; Edwards, R. Lawrence

doi:https://doi.org/10.5194/cp-16-29-2020

Articles | Volume 16, issue 1

https://doi.org/10.5194/cp-16-29-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/cp-16-29-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 16, issue 1

Research article

|

08 Jan 2020

Research article |

| 08 Jan 2020

NALPS19: sub-orbital-scale climate variability recorded in northern Alpine speleothems during the last glacial period

Gina E. Moseley, Christoph Spötl, Susanne Brandstätter, Tobias Erhardt, Marc Luetscher, and R. Lawrence Edwards

Download

Final revised paper (published on 08 Jan 2020)
Supplement to the final revised paper
Preprint (discussion started on 06 May 2019)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC1: 'Review of the paper by G. Moseley and collaborators', Anonymous Referee #1, 27 May 2019
- AC1: 'AC Response to R1', Gina E. Moseley, 29 Jul 2019
RC2: 'Comments to Moseley et al.', Anonymous Referee #2, 04 Jun 2019
- AC2: 'AC Response to R2', Gina E. Moseley, 29 Jul 2019

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (31 Jul 2019) by Dominik Fleitmann

AR by Gina E. Moseley on behalf of the Authors (12 Sep 2019) Manuscript

ED: Referee Nomination & Report Request started (02 Oct 2019) by Dominik Fleitmann

RR by Anonymous Referee #2 (03 Oct 2019)

RR by Anonymous Referee #1 (25 Oct 2019)

Suggestions for revision or reasons for rejection

I have read the revised version of Moseley et al. with interest. I appreciate the authors’ efforts to answer the comments raised by the reviewers. However, I still have a few comments that should be addressed before the manuscript is considered for publication.

Major comments:

-Page 10, line 27. With the current presentation, I don’t think that the link made between ice δ18O from Greenland and calcite δ18O is appropriate. While both are likely controlled (at least partly) by temperature, this not the same “temperature” that is considered. For Greenland, Johnsen et al. (2001) refer to local temperature (i.e. at the Greenland drilling site), which is different from the temperature controlling precipitation δ18O in the northern and central Alps. The authors have to revise their statement and be more cautious and specific.

-Page 13, line 17: This sentence should be removed as I do not think the comparison of these short events with glacial terminations is appropriate. Glacial terminations are primarily forced by orbital forcing, hence the climate background conditions are fundamentally different from the short-lived events and the time-scales are also obviously completely different.

-Figure 4. I find Figure 4 extremely difficult to read. I appreciate that the authors modified the previous version unfortunately, I find this one even harder to interpret and currently of no added values considering the presence of Table 3. A clear caption explaining the different symbols is missing and the authors have to think of a better and clearer representation of those transitions (and consider using different colors?). As said and suggested in my first review a y axis scale is missing (or at least an explanation for what is done), and it should probably also show the reference curves in the background the reference curves onto which they have performed the analysis. Uncertainties are overlapping quite largely for the transitions displayed on GICC05modelext, AICC2012 and AICC2012 (extier) which prevent a clear reading of the figure, a different representation should hence be used. Also, it is unclear what is the error bar presented: is it the error bar (5%-95% confidence interval) provided through the rampfitting analysis? Is it the error bar associated to the chronologies? Or are the authors providing an error based on the combination of the two sources of uncertainties I mention below? At the moment, it is very unclear from what is written in the caption of the figure.

-Figure 5. I have a similar comment for Figure 5. The authors need to provide a caption right next to the graph, so it is easier to figure out what the different symbols are representing, as well as the lines between the symbols. The authors should also explain the difference between panel b and panel c?
As for panel d, it is very unclear and hard to read. I don’t find it of added values considering that the results are provided in the Table 3, I would suggest removing it.

-In general, the resolution of the figures is of quite poor quality (at least looking at the pdf provided). High-resolution figures have to be provided for the published version of the paper.

Minor comments:
-Page 1, line 22: “…with the exception of Stadial-20”. I would suggest to simply write the following: “Ramp-fitting analysis further reveals that, except for one abrupt change, the timing of d18O transitions occurred…”. This will also avoid introduce a new notation such as “stadial-20”.
-Page 1, line 24: To remove “large” since the scale of the uncertainties are already quantified with “millennial-scale”.
-Page 1, line 31: To be a bit more specific regarding the “ramp-fitting” as this might not be obvious to all readers what you mean e.g. “using a ramp-fitting analysis to objectively identify the onset and the end of the abrupt transitions, we show that…”.
-Page 1, line 40: The acronym GS has to be defined.
-Page 3, line 4: To write “In the vicinity OF …”.
-Page 6, lines 21-22: To write “six” instead of 6 and “three” instead of 3 in the next line.
-Page 7, lines 27-29: To replace “accurate” by “objective” and to remove “which is often no so ambiguous”.
-Page 8, line 41: Add a space between “the” and “AICC2012”.
-Page 9, line 7: “Interestingly, with the exception of GI-23.1, the duration of transitions in the Asian monsoon are considerably longer (on multi-centennial timescales) than for the North Atlantic–sourced NALPS19 and Greenland chronologies (on multi-decadal timescales) (Table3, Fig. 5).” Could it partly be due to a lower resolution of the speleothem records? The authors should address this.
-Page 9, line 31: The formulation “a longer-duration GS-22 - GI-21.2 - GS-21.2 period” is very awkward, please reformulate.
-Page 10, line 4: Replace “an” by “a”.
-Page 10, line 18: The sentence does not seem to be finished and there is a missing reference at the end.
-Page 10, line 41: “as IT would be expected…”.
-Page 12, line 30: “Such cold reversals ARE thought…”
-Page 13, line 1: Add a space between (2012) and (Fig. 8).
-Page 13, line 7: “δ18O planktic”
-Page 12, line 35: I believe this is the first time the authors refer to the H-events, they should be briefly defined.
-Figure 2.c. Please do not introduce a new notation for stadial and interstadial events. Quite a few are circulating in the litterature and this is quite confusing already. Hence, please remove the I-X and S-X. I do not think the numbering of events is necessary in this context here anyway.
-Table 3. Write “…for NALPS δ18O (this study), NGRIP δ18O on ….”
-Table 4. Remove “various” or “different” to the caption, but don’t keep both.

Hide

ED: Publish subject to technical corrections (18 Nov 2019) by Dominik Fleitmann

AR by Gina E. Moseley on behalf of the Authors (21 Nov 2019) Author's response Manuscript

Post-review adjustments

AA: Author's adjustment | EA: Editor approval

AA by Gina E. Moseley on behalf of the Authors (19 Dec 2019) Author's adjustment

EA: Adjustments approved (06 Jan 2020) by Dominik Fleitmann

Short summary

Abrupt climate change during the last ice age can be used to provide important insights into the timescales on which the climate is capable of changing and the mechanisms that drive those changes. In this study, we construct climate records for the period 60 to 120 ka using stalagmites that formed in caves along the northern rim of the European Alps and find good agreement with the timing of climate changes in Greenland and the Asian monsoon.