Rouyer-Denimal, Louis; Govin, Aline; Bouloubassi, Ioanna; Nguyen Tu, Thanh Thuy; Albuquerque, Ana Luiza Spadano; Anquetil, Christelle; Huguet, Arnaud (2023): Reconstructed upper ocean temperature (UK'37 and TEXH86) of sediment core GL-1180, western tropical Atlantic [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.962001
Always quote citation above when using data! You can download the citation in several formats below.
Published: 2023-11-03 • DOI registered: 2023-12-02
Abstract:
During glacial terminations, the role of cross-equatorial currents in the northward spreading of warm and salty waters is essential to the reach of the following interglacial state. In the western tropical Atlantic, where the interhemispheric North Brazil current develops, most of the existing temperature records focused on the last deglaciation. Here, using a marine sediment core covering the last 305 kyr before present (BP), we present two records of the surface (mixed layer) and the subsurface (upper thermocline) temperatures based on organic proxies UK'37 and TEXH86 respectively. During the last three glacial terminations, these records exhibit large temperature increases especially in the subsurface layer. We suggest the combined influence of the thermal bipolar seesaw and the Agulhas Leakage, acting together to warm the interior South Atlantic, to explain the strong warming of the tropical western Atlantic thermocline (+ 5°C) during these periods of reduced AMOC. In addition, we propose an enhanced cross-equatorial gyre to elucidate the synchronous deglacial warming of the western and eastern sides of the tropical Atlantic. The resumption of the AMOC at the onset of the following interglacial leads to the release of heat stored in thermocline waters mainly in the whole South Atlantic, as highlighted by the sharp upper ocean cooling recorded at the end of the deglacial interval. The combination of this temperature record and previously published ones in the western tropical Atlantic confirms the strong sensitivity of the upper ocean to AMOC changes in this region.
Supplement to:
Rouyer-Denimal, Louis; Govin, Aline; Bouloubassi, Ioanna; Nguyen Tu, Thanh Thuy; Albuquerque, Ana Luiza Spadano; Anquetil, Christelle; Huguet, Arnaud (2023): Subsurface warming in the tropical Atlantic for the last 3 deglaciations: Insights from organic molecular proxies. Quaternary Science Reviews, 321, 108370, https://doi.org/10.1016/j.quascirev.2023.108370
Coverage:
Latitude: -8.450000 * Longitude: -33.550000
Minimum DEPTH, sediment/rock: 0.00 m * Maximum DEPTH, sediment/rock: 17.30 m
Event(s):
Comment:
In addition the analyses of the molecules used in these indices are :
* UK'37: Gas chromatography coupled with flame ionisation detector, Agilent, HP 6890 Series.
* TEX86: Liquid chromatography coupled with mass spectrometry, Shimadzu, LCMS 2020.
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | DEPTH, sediment/rock | Depth sed | m | Rouyer-Denimal, Louis | Geocode | |
| 2 | AGE | Age | ka BP | Rouyer-Denimal, Louis | Geocode | |
| 3 | Alkenone, unsaturation index UK'37 | UK'37 | Rouyer-Denimal, Louis | Calculated from C37 alkenones | ||
| 4 | Tetraether index of 86 carbon atoms | TEX86 | Rouyer-Denimal, Louis | Calculated from isoprenoid GDGTs |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
256 data points