Constraints on the applicability of the organic temperature proxies UK'37, TEX86 and LDI in the subpolar region around Iceland

Rodrigo-Gámiz, M.; Rampen, S. W.; de Haas, H.; Baas, M.; Schouten, S.; Sinninghe Damsté, J. S.

doi:https://doi.org/10.5194/bg-12-6573-2015

Articles | Volume 12, issue 22

https://doi.org/10.5194/bg-12-6573-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/bg-12-6573-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 12, issue 22

Research article

|

19 Nov 2015

Research article |

| 19 Nov 2015

Constraints on the applicability of the organic temperature proxies U^K'₃₇, TEX₈₆ and LDI in the subpolar region around Iceland

M. Rodrigo-Gámiz, S. W. Rampen, H. de Haas, M. Baas, S. Schouten, and J. S. Sinninghe Damsté

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Final revised paper (published on 19 Nov 2015)
Supplement to the final revised paper
Preprint (discussion started on 16 Jan 2015)

Interactive discussion

Status: closed

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

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- Supplement

RC C467: 'A review of “Constraints on the applicability of the organic temperature proxies Uk’37, TEX86, and LDI in the subpolar region around Iceland”', Jeff Salacup, 03 Mar 2015
- AC C1776: 'Reply to referee Jeff Salacup', Marta Rodrigo-Gámiz, 28 Apr 2015
RC C2424: 'Constraints on the applicability oft he organic temperature proxies UK’37, TEX86 and LDI in the subpolar region around Iceland“, by Rodrigo-Gamiz and co-authors', Gesine Mollenhauer, 27 May 2015
- AC C3562: 'Reply to referee Gesine Mollenhauer', Marta Rodrigo-Gámiz, 15 Jul 2015

Peer-review completion

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

AR by Sebastiaan Rampen on behalf of the Authors (25 Aug 2015) Author's response Manuscript

ED: Referee Nomination & Report Request started (27 Aug 2015) by Leticia Cotrim da Cunha

RR by Jeff Salacup (10 Sep 2015)

RR by Gesine Mollenhauer (14 Sep 2015)

Suggestions for revision or reasons for rejection

Methods:
Were the SPM samples taken in 2011 at ~5 m water depth also taken with a MacLane pump?
Details on the sediment trap: Surface area of the collection funnel? At what depth was the trap moored?

Results:
Statements on the flux maxima occurring exaclty at the beginning and at the end of the trap deployment period are problematic. Please re-word to „highest fluxes were recorded...“

Discussion:
Lines 392-395: From the data displayed in Figure 4, a sinking rate of 230 m per day seems unrealistically high to me. From the offset (UK’37 maxima in trap cups 13-17, SST maximum in July 2011) it looks more like roughly 10 m per day to me. Please explain in more detail how the sinking velocities were derived (delay in days).
Lines 475-478: Here it is ignored that GDGTs cannot be exported instantaneously to depth (1850 m water depth). There must be a delay in the temperature signal produced at the surface and collected in sediment traps, which relates to the average sinking velocity of GDGT-bearing particles, which is likely smaller than that for alkenone-bearing particles. The discussion here is in contradiction to the newly inserted paragraphs on the UK’37 record and its implications for sinking velocity of alkenones and with what follows in lines 497-499.
Line 490: There is of course no difference in the result when using different calibrations for comparing flux-weighted TEX86 and sediment TEX86! They are conversions of the TEX value, and that is similar for flux-weighted mean and surface sediment.

Data: I have not been able to find supplementary table 1, in which the according to table caption 2 the proxy values are

Typos etc.:
Line 319: ....LDI-based temperatures vary....
Line 411: omit one “only“
Line 422: “northermost“ instead of “most northern“
Line 437/438: delete “values“ and re-word “the difference with summer temperatures ....“
Line 453: “from 0.7 µm pore diameter filters”

Table 1: refer to “upper trap” and “lower trap” instead of “trap top” and “trap bottom”
Table 3: I am surprised to read that satellite temperatures are available for 20 m water depth? I was always informed that satellites could only record surface temperatures. Please clarify.

Referee Report: PDF

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ED: Publish subject to minor revisions (Editor review) (21 Sep 2015) by Leticia Cotrim da Cunha

AR by Sebastiaan Rampen on behalf of the Authors (05 Oct 2015) Author's response

ED: Publish as is (23 Oct 2015) by Leticia Cotrim da Cunha

AR by Sebastiaan Rampen on behalf of the Authors (02 Nov 2015)

Short summary

This research reports a test of the applicability of three organic-derived temperature proxies (UK'37, TEX86 and LDI) at high latitudes around Iceland. A range of samples including suspended particular material (SPM), trapped descending particles and surface sediments were collected to test the different proxies in the water column and the sediment.The combination of three independent SST organic proxies provided important information about seasonality and differences in habitat depth.