Sea-surface temperature, productivity and hydrological changes in the Northern Indian Ocean (Maldives) during the interval ~575-175 ka (MIS 14 to 7)

Alonso-García, Montserrat; Rodrigues, Teresa; Abrantes, F.; Padilha, Maria do Rosário de Fátima; Zarikian, C.A. Alvarez; Kunkelová, Tereza; Wright, James D.; Betzler, Christian

doi:10.1016/j.palaeo.2019.109376

Cited by 10 publications

(21 citation statements)

References 92 publications

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“…Considering MIS11 is a warm Pleistocene "super interglacial" associated with extreme surface warming in the higher latitudes (+2°C-5°C according to Jouzel et al, 2007;Milker et al, 2013), a larger temperature gradient is anticipated across MIS11c-12. Furthermore, in agreement with tropical studies (Alonso-García et al, 2019;Milker et al, 2013) both shallow-dwelling G. ruber (w) and G. bulloides show a +0.37°C temperature increase for the Maldivian surface waters during MIS11c in comparison to the Recent core-top samples. Moreover, the typically shallow-thermocline dwelling P. obliquiloculata (w/c) shows a similar increase for the thermocline waters (+0.21°C).…”

Section: Discrete Inner Sea Water Column Characteristicssupporting

confidence: 88%

Monsoon and Tropical Climate Forcing on the Physicochemical and Thermocline Characteristics of the Maldives Inner Sea: Insights From Marine Isotope Stages 1–2 and 10–13

Stainbank

Spezzaferri

Rüggeberg

et al. 2021

Paleoceanog and Paleoclimatol

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The Maldivian archipelago, in the equatorial Indian Ocean, provides a unique location to assess long‐term basin‐wide South Asian Monsoon (SAM) processes as well as its response during climatic extremes. This insight is beneficial to better understand future SAM influences on the Maldives Inner Sea physicochemical characteristics and its diverse tropical ecosystems in a warming world. This study uses samples from International Ocean Discovery Program Expedition 359, drilled within the Inner Sea drift deposits. Multiple foraminiferal species (n = 15) and proxies (δ18O, δ13C, and Mg/Ca) are used to assess glacial‐interglacial SAM dynamics influencing the Inner Sea conditions across Marine Isotope Stages (MIS) 1–2 and 10–13. The summer SAM is modulated by insolation and atmospheric CO2 and has a predominant impact on the northern Indian Ocean surface salinity. As with present‐day observations, a strong summer monsoon resulted in large basin‐wide δ18Osw (salinity) gradients during the interglacials. Moreover, at the MIS11 minimum (MIS11c), a recognized analog for the present‐day, sea surface temperatures (SSTs) were warmer than the present with a stronger summer SAM. This led to an expanded surface mixed layer and strong thermocline, resulting in a highly stratified water column and prominent oxygen minimum zone in the Inner Sea during MIS11c. SSTs in the Maldives are projected to increase at the end of this century and based on the reality that current warming (anthropogenically driven) is much faster than seen during MIS11, the Maldivian tropical coral reef and benthic shoal ecosystems will be subject to increasing stress.

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Section: Discrete Inner Sea Water Column Characteristicssupporting

confidence: 88%

Monsoon and Tropical Climate Forcing on the Physicochemical and Thermocline Characteristics of the Maldives Inner Sea: Insights From Marine Isotope Stages 1–2 and 10–13

Stainbank

Spezzaferri

Rüggeberg

et al. 2021

Paleoceanog and Paleoclimatol

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“…From bottom to top: A) Results of grain-size analyses of the Site U1467 sediments: bulk sediment mean grain size (μm, dark red circles) and the proportion (%) of sand fraction (>63 μm) in the samples analyzed for ostracods (blue squares); B) total ostracod abundance (number of valves per 30 g of sediment; dark red line); C) ostracod diversity expressed by the Simpson index (dark green line); D) total alkenone concentration (ng/g; purple line), from Alonso- Garcia et al (2019) and this study; E) the higher plant n-alcohols/n-alkanes (HPA) ventilation index (green line); F) XRF derived elemental ratios of Ca/Fe (light blue line) and Fe/K (orange line) of the sediment cores from Site U1467; and G) the Site U1467 benthic δ 18 O record from Stainbank et al (2020) measured on the benthic foraminifer Cibicides mabahethi. The HPA index indicates the degree of organic matter preservation, and therefore oxygenation, on the seafloor, and the total alkenone concentration sea surface primary productivity (Alonso- Garcia et al, 2019). No biomarker data is available for MIS 1-6.…”

Section: Figmentioning

confidence: 99%

“…We use the age model from Alonso- Garcia et al (2019) which is consistent with the age model of Stainbank et al (2020) based on the newly produced planktic and benthic foraminifer δ 18 O records from Site U1467 correlated to the global stack reference curve of Ahn et al (2017). The benthic δ 18 O record derived from the benthic foraminifer Cibicides mabahethi is shown in Fig.…”

Section: The Age Modelmentioning

confidence: 99%

“…The total concentration of n-alkanes and C 37 alkenones for the interval from MIS 14 to 7 was already published in Alonso- Garcia et al (2019). In that study, C 37 alkenone concentration was interpreted as a proxy to infer surface water productivity related to coccolithophores, and selected n-alkanes and n-alcohols were interpreted as a proxy for hydrological balance in the nearby continents, given that long-chain nalkanes and n-alcohols are organic compounds that reflect continental input because they come from epicuticular leaf waxes of higher plants (Poynter and Eglinton, 1990;Poynter et al, 1989).…”

Section: Organic Compoundsmentioning

confidence: 99%

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Ostracod response to monsoon and OMZ variability over the past 1.2 Myr

Zarikian

Nadiri

Alonso-García

et al. 2022

Marine Micropaleontology

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“…However, different conclusions were obtained, e.g., with 8 kyr phase lag in Arabian Sea sediments (Clemens et al, , 2010Clemens and Prell, 2003), and without phase lag in Bay of Bengal (Weber et al, 2018;Lauterbach et al, 2020). The equatorial Indian Ocean region is also affected by the Indian monsoon (Figure 1) (e.g., Tomczak and Godfrey, 2003;Betzler et al, 2013;Lüdmann et al, 2013;Bunzel et al, 2017;Alonso-Garcia et al, 2019), but there is a lack of discussion on the phase difference between ISM and NHSI. Therefore, in order to demonstrate whether this phase difference is unique to the sedimentary records of the Indian Ocean, it is necessary to find evidence in wider Indian monsoon control regions, especially in the equatorial Indian Ocean (e.g., Ninetyeast ridge and Maldives).…”

Section: Conclusion and The Way Forwardmentioning

confidence: 99%

Variability of indian monsoon and its forcing mechanisms since late quaternary

et al. 2022

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The Indian monsoon is an important part of the global monsoon system, allowing important transfers of moisture at a large geographical scale and deeply affecting human populations and economic prosperity of regions. The tropical summer monsoon in the Northern Hemisphere is generally considered to be driven by low latitude solar radiation. Therefore, the summer monsoon strength is near zero-phase to the maximum of Northern Hemisphere Summer Insolation (NHSI). However, records from the Arabian Sea and some other parts of the Indian Ocean (e.g., Andaman Sea) show that a ∼8 kyr phase difference exists between the Indian summer monsoon (ISM) strength and the northern Hemisphere Summer Insolation maxima, which is obviously different from the records of stalagmites in the East Asia and other marine sediments (e.g., Bay of Bengal). This leads to the “sea-land precession phase paradox” in indian summer monsoon research. This paper systematically summarizes the Indian monsoon variability on orbital scale indicated by various records from the Indian monsoon regions (including oceans and continents) since the late Quaternary. The orbital forcing of Indian monsoon, the potential phase difference between indian summer monsoon and northern Hemisphere Summer Insolation and its possible forcing mechanism(s) are further discussed. The observed phase lag between indian summer monsoon and northern Hemisphere Summer Insolation may be controlled by the Atlantic Meridional Overturning Circulation (AMOC), latent heat transfer between the southern Indian Ocean and the Asian continent, or caused by the lack of tightly coupling between the Arabian Sea summer monsoon proxies and the monsoon intensity. In addition, it is still unclear whether previous monsoon proxies can provide a strong constraint on the intensity of summer monsoon. Environmental magnetism has been widely used in high-resolution dating and the analysis of paleoclimate variabilities in marine and terrestrial sediments, due to its high sensitivity on the rainfall and temperature. Therefore, in order to solve these issues, it is necessary to combine magnetic parameters with geochemical and paleontological parameters for more systematic work in the future.

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Sea-surface temperature, productivity and hydrological changes in the Northern Indian Ocean (Maldives) during the interval ~575-175 ka (MIS 14 to 7)

Cited by 10 publications

References 92 publications

Monsoon and Tropical Climate Forcing on the Physicochemical and Thermocline Characteristics of the Maldives Inner Sea: Insights From Marine Isotope Stages 1–2 and 10–13

Monsoon and Tropical Climate Forcing on the Physicochemical and Thermocline Characteristics of the Maldives Inner Sea: Insights From Marine Isotope Stages 1–2 and 10–13

Ostracod response to monsoon and OMZ variability over the past 1.2 Myr

Variability of indian monsoon and its forcing mechanisms since late quaternary

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