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Article: Rapid switch in monsoon-wind induced surface hydrographic conditions of the eastern Arabian Sea during the last deglaciation

Singh, Arun Deo / Anand, Pallavi / Ganeshram, Raja S / Jung, Simon J.A / Kroon, Dick

Elsevier Ltd and INQUA Quaternary international. 2018 June 20, v. 479

2018

Abstract: Surface water hydrography in the Arabian Sea is primarily governed by the Asian monsoon wind system. Changes in the composition of fossil planktic foraminiferal assemblages and sea surface temperatures (SST) in sediment core SK17, retrieved from offshore ...

Abstract	Surface water hydrography in the Arabian Sea is primarily governed by the Asian monsoon wind system. Changes in the composition of fossil planktic foraminiferal assemblages and sea surface temperatures (SST) in sediment core SK17, retrieved from offshore of central India, are used to decipher past changes in sea-surface hydrographic conditions linked mainly to the winter monsoon winds. The planktic foraminiferal assemblage and the SST records indicate a rapid switch in sea-surface hydrographic conditions around 17.5 ka BP marking the end of last glacial period. The data show that intensified winter winds during 17.5–23.5 ka BP, resulted in nutrient injection into surface waters and eutrophic conditions, mainly through deep vertical mixing and/or moderate upwelling; and reduction in winter wind intensity caused stratification characterized by the high tropical SST since 17.5 ka BP. The timing of the rapid switch in seawater conditions caused by a drop in strength of winter monsoon winds is coeval with the cold climate excursion in the northern hemisphere (Heinrich Event 1), suggesting that the two areas are climatically linked.
Keywords	cold zones ; eutrophication ; fossils ; glaciation ; mixing ; monsoon season ; seawater ; sediments ; surface temperature ; surface water ; wind ; winter ; Arabian Sea ; India
Language	English
Dates of publication	2018-0620
Size	p. 3-11.
Publishing place	Elsevier Ltd
Document type	Article
ISSN	1040-6182
DOI	10.1016/j.quaint.2018.03.027
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Atlantic Deep-water Response to the Early Pliocene Shoaling of the Central American Seaway.

Bell, David B / Jung, Simon J A / Kroon, Dick / Hodell, David A / Lourens, Lucas J / Raymo, Maureen E

Scientific reports

2015 Volume 5, Page(s) 12252

Abstract: The early Pliocene shoaling of the Central American Seaway (CAS), ~4.7-4.2 million years ago (mega annum-Ma), is thought to have strengthened Atlantic Meridional Overturning Circulation (AMOC). The associated increase in northward flux of heat and ... ...

Abstract	The early Pliocene shoaling of the Central American Seaway (CAS), ~4.7-4.2 million years ago (mega annum-Ma), is thought to have strengthened Atlantic Meridional Overturning Circulation (AMOC). The associated increase in northward flux of heat and moisture may have significantly influenced the evolution of Pliocene climate. While some evidence for the predicted increase in North Atlantic Deep Water (NADW) formation exists in the Caribbean and Western Atlantic, similar evidence is missing in the wider Atlantic. Here, we present stable carbon (δ(13)C) and oxygen (δ(18)O) isotope records from the Southeast Atlantic-a key region for monitoring the southern extent of NADW. Using these data, together with other δ(13)C and δ(18)O records from the Atlantic, we assess the impact of the early Pliocene CAS shoaling phase on deep-water circulation. We find that NADW formation was vigorous prior to 4.7 Ma and showed limited subsequent change. Hence, the overall structure of the deep Atlantic was largely unaffected by the early Pliocene CAS shoaling, corroborating other evidence that indicates larger changes in NADW resulted from earlier and deeper shoaling phases. This finding implies that the early Pliocene shoaling of the CAS had no profound impact on the evolution of climate.
Language	English
Publishing date	2015-07-20
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	2615211-3
ISSN	2045-2322 ; 2045-2322
ISSN (online)	2045-2322
ISSN	2045-2322
DOI	10.1038/srep12252
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Surface and deep water changes in the subpolar North Atlantic during Termination II and the Last Interglaciation

Bauch, Henning A. / Erlenkeuser, Helmut / Jung, Simon J. A. / Thiede, Jörn

2010

Abstract: To reconstruct the history of water mass exchange between the NE Atlantic and the Nordic seas, sediment cores from ∼2 km water depth were studied across Termination II (TII) and through the last interglaciation (MIS5e). During early TII the sudden ... ...

Abstract	To reconstruct the history of water mass exchange between the NE Atlantic and the Nordic seas, sediment cores from ∼2 km water depth were studied across Termination II (TII) and through the last interglaciation (MIS5e). During early TII the sudden appearance of the low-latitude planktonic foraminifera Beella megastoma is noted in both regions along with a steep decrease in benthic foraminiferal δ18O. Since other proxies indicate that surface waters were cold and stratified because of meltwater, conditions which prevented near-surface thermohaline circulation and vertical convection in the Nordic seas, water mass exchange between the two areas occurred at the subsurface. During later TII, surface conditions changed, and this subsurface circulation style was eventually replaced by vertical convection. In the Nordic seas, B. megastoma vanished from the record together with ice-rafted debris (IRD) at the end of TII, while subpolar foraminiferal abundance rose. Peak interglacial conditions with intensive vertical convection now fully developed, generating a bottom water temperature gradient of ∼4°C between the two areas. However, surface water temperatures deteriorated in the Nordic seas already notably before IRD recurred, and δ18O increased at the end of MIS5e.
Subject code	551 ; 550
Language	English
Publisher	AGU (American Geophysical Union)
Publishing country	de
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Book ; Thesis: Wassermassenaustausch zwischen NE-Atlantik und Nordmeer während der letzten 300000/80000 Jahre im Abbild stabiler O- und C-Isotope

Jung, Simon J. A

(Berichte aus dem Sonderforschungsbereich 313 ; 61)

1996

Author's details	Simon J. A. Jung
Series title	Berichte aus dem Sonderforschungsbereich 313 ; 61
Language	German
Size	104 S., Anh, zahlr. graph. Darst
Publishing place	Kiel
Document type	Book ; Thesis
Thesis / German Habilitation thesis	Univ., Diss.--Kiel, 1996
Database	Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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Book ; Thesis: Wassermassenaustausch zwischen NE-Atlantik und Nordmeer während der letzten 300000/80000 Jahre im Abbild stabiler O- und C-Isotope

Jung, Simon J. A

(Berichte aus dem Sonderforschungsbereich 313 ; 61)

1996

Author's details	Simon J. A. Jung
Series title	Berichte aus dem Sonderforschungsbereich 313 ; 61
Language	German
Size	104 S., Anh, zahlr. graph. Darst
Publishing place	Kiel
Document type	Book ; Thesis
Thesis / German Habilitation thesis	Univ., Diss.--Kiel, 1996
Database	Former special subject collection: coastal and deep sea fishing

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Thesis ; Online: Wassermassenaustausch zwischen NE-Atlantik und Nordmeer während der letzten 300.000/80.000 Jahre im Abbild stabiler O- und C-lsotope

Jung, Simon J. A.

1996

Language	German
Publishing country	de
Document type	Thesis ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Book ; Online: Geochemistry and morphometry on planktonic foraminifera, supplementary data to: de Moel, Hans; Ganssen, Gerald M; Peeters, Frank J C; Jung, Simon J A; Kroon, Dick; Brummer, Geert-Jan A; Zeebe, Richard E (2009): Planktic foraminiferal shell thinning in the Arabian Sea due to anthropogenic ocean acidification?. Biogeosciences, 6, 1917-1925

de Moel, Hans / Brummer, Geert-Jan A / Ganssen, Gerald M / Jung, Simon J A / Kroon, Dick / Peeters, Frank J C / Zeebe, Richard E

2010

Abstract: About one third of the anthropogenic carbon dioxide (CO2) released into the atmosphere in the past two centuries has been taken up by the ocean. As CO2 invades the surface ocean, carbonate ion concentrations and pH are lowered. Laboratory studies ... ...

Abstract	About one third of the anthropogenic carbon dioxide (CO2) released into the atmosphere in the past two centuries has been taken up by the ocean. As CO2 invades the surface ocean, carbonate ion concentrations and pH are lowered. Laboratory studies indicate that this reduces the calcification rates of marine calcifying organisms, including planktic foraminifera. Such a reduction in calcification resulting from anthropogenic CO2 emissions has not been observed, or quantified in the field yet. Here we present the findings of a study in the Western Arabian Sea that uses shells of the surface water dwelling planktic foraminifer Globigerinoides ruber in order to test the hypothesis that anthropogenically induced acidification has reduced shell calcification of this species. We found that light, thin-walled shells from the surface sediment are younger (based on 14C and d13C measurements) than the heavier, thicker-walled shells. Shells in the upper, bioturbated, sediment layer were significantly lighter compared to shells found below this layer. These observations are consistent with a scenario where anthropogenically induced ocean acidification reduced the rate at which foraminifera calcify, resulting in lighter shells. On the other hand, we show that seasonal upwelling in the area also influences their calcification and the stable isotope (d13C and d18O) signatures recorded by the foraminifera shells. Plankton tow and sediment trap data show that lighter shells were produced during upwelling and heavier ones during non-upwelling periods. Seasonality alone, however, cannot explain the 14C results, or the increase in shell weight below the bioturbated sediment layer. We therefore must conclude that probably both the processes of acidification and seasonal upwelling are responsible for the presence of light shells in the top of the sediment and the age difference between thick and thin specimens.
Language	English
Dates of publication	2010-9999
Size	Online-Ressource
Publisher	PANGAEA - Data Publisher for Earth & Environmental Science
Publishing place	Bremen/Bremerhaven
Document type	Book ; Online
Note	This dataset is supplement to doi:10.5194/bg-6-1917-2009
DOI	10.1594/PANGAEA.746072
Database	Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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Book ; Online: Age, pteropoda counts and Limacina dissolution index of sediment core NIOP-C2_905_BC, supplementary data to: Kl?cker, Ralph; Ganssen, Gerald M; Jung, S J A; Kroon, Dick; Henrich, R?diger (2005): Late Quaternary millennial-scale variability in pelagic aragonite preservation off Somalia. Marine Micropaleontology, 59(3-4), 171-183

Kl?cker, Ralph / Ganssen, Gerald M / Henrich, R?diger / Jung, Simon J A / Kroon, Dick

2005

Abstract: In order to better understand Late Quaternary pelagic aragonite preservation in the western Arabian Sea we have investigated a high-resolution sediment core 905 off Somalia. Pteropod preservation is enhanced in times of reduced monsoon-driven ... ...

Abstract	In order to better understand Late Quaternary pelagic aragonite preservation in the western Arabian Sea we have investigated a high-resolution sediment core 905 off Somalia. Pteropod preservation is enhanced in times of reduced monsoon-driven productivity, indicated by low amounts of Corg and low barium to aluminium (Ba/Al) ratios. All periods corresponding to Heinrich events in the North Atlantic are represented by maxima in shell preservation of the common pteropod Limacina inflata (LDX values <2, except for H5-equivalent with a poorer shell preservation, LDX >2.66). Good shell preservation is also found during stadials at 52.1-53.2, 36, 33.2, and 31.9 ka. Relative abundance of pteropods and their fragments in the coarse fraction reaches maxima during Marine Isotope Stage (MIS) 5.2, during time-equivalents of Heinrich events 4-6 and in stadials at not, vert, similar 53, not, vert, similar 42.5, and 41.4 ka. On longer time scales, the pteropod abundance corresponds to the 'Indo-Pacific carbonate preservation type' with poor preservation during interglacials and better preservation during glacials. Late MIS 5 to early MIS 4 sections (84.1-64.8 ka) and the Late Holocene interval (6.5-0 ka) of core 905 contain only traces of pteropods. The early Holocene (9.2-6.5 ka) part is characterized by low pteropod amounts. Between 64.8 and 43.4 ka strong fluctuations occur and an intermediate average relative pteropod abundance is revealed. Between 43.4 and 9.2 ka the highest amounts in relative pteropod abundance in core 905 are observed. Besides the regional monsoonal influence on deepwater chemistry, changes in deepwater circulation occurring on glacial/interglacial and stadial/interstadial time scales might have affected pteropod preservation. However, it remains elusive whether 1) deep water formation in the Arabian Sea, 2) inflow of Glacial North Atlantic Intermediate Water or 3) change in water mass properties of the Circumpolar Deep Water (which is the water mass currently bathing this site) contributed to the observed pteropod preservation pattern. REFERENCE: Kl?cker, Ralph; Ivanochko, Tara S; Brummer, Geert-Jan A; Jung, S J A; Ganssen, Gerald M; Kroon, Dick; Ganeshram, Raja S; Henrich, R?diger (2007): Variation in production, input and preservation of metastable calcium carbonate off Somalia during the last 90 000 years. Quaternary Science Reviews, 26(19-21), 2674-2683 Kl?cker, Ralph (2005): Late Quaternary pelagic aragonite preservation in the Arabian Sea and its paleoceanographic implications. PhD Thesis, Elektronische Dissertationen an der Staats- und Universit?tsbibliothek Bremen, Germany, 96 pp
Language	English
Dates of publication	2005-9999
Size	Online-Ressource
Publisher	PANGAEA - Data Publisher for Earth & Environmental Science
Publishing place	Bremen/Bremerhaven
Document type	Book ; Online
Note	This dataset is cited by doi:10.1016/j.quascirev.2007.10.001 ; This dataset is cited by urn:urn:nbn:de:gbv:46-diss000102782 ; This dataset is supplement to doi:10.1016/j.marmicro.2006.02.004
DOI	10.1594/PANGAEA.328911
Database	Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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Book ; Online: Age determination and stable isotope record of foraminifera of sediment core SO82_5-2, supplementary data to: van Kreveld, Shirley A; Sarnthein, Michael; Erlenkeuser, Helmut; Grootes, Pieter Meiert; Jung, Simon J A; Pflaumann, Uwe; Voelker, Antje HL (2000): Potential links between surging ice sheets, circulation changes, and the Dansgaard-Oeschger cycles in the Irminger Sea, 60-18 kyr. Paleoceanography, 15(4), 425-442

van Kreveld, Shirley A / Erlenkeuser, Helmut / Grootes, Pieter Meiert / Jung, Simon J A / Pflaumann, Uwe / Sarnthein, Michael / Voelker, Antje HL

2000

Abstract: Surface and deepwater paleoclimate records in Irminger Sea core SO82-5 (59?N, 31?W) and Icelandic Sea core PS2644 (68?N, 22?W) exhibit large fluctuations in thermohaline circulation (THC) from 60 to 18 calendar kyr B.P., with a dominant periodicity of ... ...

Abstract	Surface and deepwater paleoclimate records in Irminger Sea core SO82-5 (59?N, 31?W) and Icelandic Sea core PS2644 (68?N, 22?W) exhibit large fluctuations in thermohaline circulation (THC) from 60 to 18 calendar kyr B.P., with a dominant periodicity of 1460 years from 46 to 22 calendar kyr B.P., matching the Dansgaard-Oeschger (D-O) cycles in the Greenland Ice Sheet Project 2 (GISP2) temperature record [Grootes and Stuiver, 1997, doi:10.1029/97JC00880]. During interstadials, summer sea surface temperatures (SSTsu) in the Irminger Sea averaged to 8?C, and sea surface salinities (SSS) averaged to ~36.5, recording a strong Irminger Current and Atlantic THC. During stadials, SSTsu dropped to 2?-4?C, in phase with SSS drops by ~1-2. They reveal major meltwater injections along with the East Greenland Current, which turned off the North Atlantic deepwater convection and hence the heat advection to the north, in harmony with various ocean circulation and ice models. On the basis of the IRD composition, icebergs came from Iceland, east Greenland, and perhaps Svalbard and other northern ice sheets. However, the southward drifting icebergs were initially jammed in the Denmark Strait, reaching the Irminger Sea only with a lag of 155-195 years. We also conclude that the abrupt stadial terminations, the D-O warming events, were tied to iceberg melt via abundant seasonal sea ice and brine water formation in the meltwater-covered northwestern North Atlantic. In the 1/1460-year frequency band, benthic ?18O brine water spikes led the temperature maxima above Greenland and in the Irminger Sea by as little as 95 years. Thus abundant brine formation, which was induced by seasonal freezing of large parts of the northwestern Atlantic, may have finally entrained a current of warm surface water from the subtropics and thereby triggered the sudden reactivation of the THC. In summary, the internal dynamics of the east Greenland ice sheet may have formed the ultimate pacemaker of D-O cycles. REFERENCE: Sarnthein, Michael; Stattegger, Karl; Dreger, Derek; Erlenkeuser, Helmut; Grootes, Pieter Meiert; Haupt, Bernd J; Jung, Simon J A; Kiefer, Thorsten; Kuhnt, Wolfgang; Pflaumann, Uwe; Sch?fer-Neth, Christian; Schulz, Hartmut; Schulz, Michael; Seidov, Dan; Simstich, Johannes; van Kreveld, Shirley A; Vogelsang, Elke; Voelker, Antje HL; Weinelt, Mara (2001): Fundamental modes and abrupt changes in North Atlantic circulation and climate over the last 60 ky - concepts, reconstruction and numerical modeling. In: Sch?fer, W; Ritzrau, M; Schl?ter & J. Thiede (eds.) The Northern North Atlantic: A Changing Environment, Springer Verlag, Berlin, 500 pp, 365-410
Language	English
Dates of publication	2000-9999
Size	Online-Ressource
Publisher	PANGAEA - Data Publisher for Earth & Environmental Science
Publishing place	Bremen/Bremerhaven
Document type	Book ; Online
Note	This dataset is cited by doi:10.1007/978-3-642-56876-3_21 ; This dataset is supplement to doi:10.1029/1999PA000464
DOI	10.1594/PANGAEA.735017
Database	Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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