Pleistocene Precipitation Balance in the Amazon Basin Recorded in Deep Sea Sediments

Harris, Sara; Mix, Alan C

doi:10.1006/qres.1998.2008

Cited by 119 publications

(70 citation statements)

References 52 publications

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“…The monsoon feeds off this moisture source and is, hence, strengthened at 506 ka. The South American DJF monsoon is enhanced in the MIS-13 experiments, endorsing the paleo-observations of wetter conditions from the Amazon basin (Harris and Mix 1999). The terrigenous sediments from the Ceara Rise off the Brazilian coast mainly originate from the Amazon lowlands, having been transported by the Amazon River.…”

Section: The Mis-13 Climate a Model Climatology And Comparison To Gesupporting

confidence: 75%

“…There is a DJF increase in precipitation of 0.5-3.0 mm day 21 over the Amazon lowlands in the MIS-13 no-ice model, as seen in Fig. 2d, the model hence lends support to the data of Harris and Mix (1999). With regards to sea ice, there is an increase in the northward extent and amount in the Southern Ocean throughout the whole year.…”

Section: The Mis-13 Climate a Model Climatology And Comparison To Gesupporting

confidence: 61%

“…Evidence of a strong North African monsoon during MIS-13 is found from a thick layer of sapropel in a core from the Mediterranean Sea (Rossignol-Strick et al 1998). Indications of positive rainfall anomalies at the time are also found in observations from the Amazon basin (Harris and Mix 1999). Ostracod data from England indicate that the local temperatures could have been similar to today, with a larger seasonality and possibly colder-or much colder-winters (Holmes et al 2010).…”

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confidence: 53%

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The Climate of the MIS-13 Interglacial according to HadCM3

et al. 2013

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The climate of the Marine Isotopic Stage 13 (MIS-13) is explored in the fully coupled atmosphereocean general circulation model the Hadley Centre Coupled Model, version 3 (HadCM3). It is found that the strong insolation forcing at the time imposed a strengthened land-ocean thermal contrast, resulting in an intensified summer monsoon over Asia. The addition of land ice over North America and Eurasia results in a stationary wave feature across the Eurasian continent. This leads to a high pressure anomaly over the Sea of Japan with increased advection of warm moist air onto the Chinese landmasses. This in turn reinforces the East Asian summer monsoon (EASM), highlighting the counterintuitive notion that, depending on the background insolation and its size, ice can indeed contribute to strengthening the EASM. The modeling results support the geological record indication of a strong EASM 500 000 years ago. Furthermore, Arctic Oscillation, El Niño-Southern Oscillation, and Indian Ocean dipole-like teleconnection features are discussed in the MIS-13 environment. It is shown that the change in the tropical Pacific sea surface temperature has the potential to impact the North Atlantic climate through an atmospheric ''bridge.''

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Section: The Mis-13 Climate a Model Climatology And Comparison To Gesupporting

confidence: 75%

Section: The Mis-13 Climate a Model Climatology And Comparison To Gesupporting

confidence: 61%

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confidence: 53%

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The Climate of the MIS-13 Interglacial according to HadCM3

et al. 2013

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“…While this temperature-diversity relationship may be causal, it is also possible that diversity is instead driven by some other environmental driver that, like temperature, tracks glacial-interglacial cycles. Such factors might be mediated by latitudinal shifts in the Intertropical Convergence Zone (ITCZ) and changes in North Brazil Current (33,47), or changes in deep water characteristics reflecting the relative influence of North Atlantic Deep Water (NADW) versus Antarctic Bottom Water (AABW) (48,49). NADW and AABW differ in temperature, nutrients contents, and salinity, although at present there is not much evidence that nutrients and salinity have much influence on deep-sea diversity.…”

Section: Resultsmentioning

confidence: 99%

Temporal latitudinal-gradient dynamics and tropical instability of deep-sea species diversity

Yasuhara

Hunt²,

Cronin³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

102

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A benthic microfaunal record from the equatorial Atlantic Ocean over the past four glacial-interglacial cycles was investigated to understand temporal dynamics of deep-sea latitudinal species diversity gradients (LSDGs). The results demonstrate unexpected instability and high amplitude fluctuations of species diversity in the tropical deep ocean that are correlated with orbital-scale oscillations in global climate: Species diversity is low during glacial and high during interglacial periods. This implies that climate severely influences deep-sea diversity, even at tropical latitudes, and that deep-sea LSDGs, while generally present for the last 36 million years, were weakened or absent during glacial periods. Temporally dynamic LSDGs and unstable tropical diversity require reconsideration of current ecological hypotheses about the generation and maintenance of biodiversity as they apply to the deep sea, and underscore the potential vulnerability and conservation importance of tropical deep-sea ecosystems.deep-sea Ostracoda ͉ global climate change ͉ latitudinal species diversity gradients ͉ macroecology ͉ Quaternary paleoceanography L atitudinal species diversity gradients (LSDGs), the patterns in which tropical regions contain more species than high latitudes, are one of the most basic ecological patterns on the earth (1). In the modern ocean, deep-sea bivalves, gastropods, isopods, cumaceans, and foraminifera all show strong LSDGs (2-6), and studies of benthic foraminifera assemblages indicate that the deep-sea gradients were established Ϸ36 million years ago (7). The environmental stability hypothesis holds that stability in tropical (1,8), and deep-sea (9, 10) environments might enhance species diversity, but there is now evidence for highly fluctuating high-latitude deep-sea diversity during Quaternary climatic cycles (11)(12)(13)(14)(15)(16). Surprisingly little attention has been given to understanding low-latitude deepsea diversity and the temporal dynamics of the LSDGs. Although pollen records suggest a persistent latitudinal diversity gradient existed in terrestrial ecosystems over the last 13,000 years (17, 18), we know of no studies of species-level temporal dynamics of LSDGs based on fossil assemblages from marine environments, despite the sensitivity of marine ecosystems to climatic change (12,13,(19)(20)(21)(22)(23)(24).The Ostracoda (Crustacea) are an important component of the deep-sea benthos (25)(26)(27), and the only commonly fossilized metazoan group in deep-sea sediments (12,13,28). Their various habitats and ecological preferences represent a wide range of deep-sea benthic niches, and their fossil record is considered representative of the benthic community (12,13,28). Furthermore, large (Ϸ130 m) glacial-interglacial sea-level changes (29), which drastically altered shallow-marine environments, had negligible effects on deep-sea habitats (e.g., Ͼ1,000 m water depth). Here, we examine low-latitude Quaternary records of deep-sea ostracods and temporal changes in LSDGs in the North Atlantic Oc...

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“…The presence of small amounts of goethite and/or hematite measurably alters the first derivative spectrum of color reflectance in the visible light range . Derived from color reflectance spectra, the fraction of goethite in the total iron oxide [G / (G + H)] has therefore been used as a terrestrial precipitation indicator and has been demonstrated to be useful in Amazon Basin sediment studies (Harris and Mix 1999).…”

Section: Color Spectrum Estimations For Goethite and Hematitementioning

confidence: 99%

Sea Surface Temperature, Productivity, and Terrestrial Flux Variations of the Southeastern South China Sea over the Past 800000 Years (IMAGESMD972142)

Shiau¹,

Yu²,

Wei³

et al. 2008

Terr. Atmos. Ocean. Sci.

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Variations in sea surface temperature (SST), productivity, and biogenic components such as total organic carbon (TOC), carbonate, and opal contents measured from IMAGES (International Marine Global Changes Study) core MD972142 provide information about long-term paleoceanographic changes during the past~870000 years in the southeastern South China Sea (SCS). MD972142 U 37 k' -SSTs varied from 25 to 29°C, paralleling the glacial to interglacial changes. MD972142 biogenic components show relatively high carbonate and opal, and low TOC contents in interglacial stages, and low carbonate and opal and high TOC contents in glacial stages, and these variations appear to be sensitive to regional terrestrial sediment input and productivity. Our analysis indicates that the MD972142 carbonate record is primarily controlled by terrestrial sediment inputs that are associated with sea level fluctuations during past glacial-interglacial stages. The TOC record reflects past glacial-interglacial changes in both monsoon-induced productivity and terrestrial organic matter input in the SCS. The TOC record exhibits several short-term peaks that are associated with lower U 37 k' -SSTs (especially in MIS 2 -4, 10, 12), perhaps implying a much strengthened winter monsoon. The opal record shows relatively high content in most interglacial stages, which appears to be linked to increased summer monsoon upwelling or increased siliceous sediment input by more precipitation and river runoff during warm climate conditions. The TOC and opal contents both show long-term increasing trends since the mid-Brunhes, most noticeably from~330 kya. The long-term trends observed in this study are most likely attributable to changes in SCS hydrography, productivity, and/or preservation in response to the increased strength of the East Asian monsoon system on possibly tectonic timescales.

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Pleistocene Precipitation Balance in the Amazon Basin Recorded in Deep Sea Sediments

Cited by 119 publications

References 52 publications

The Climate of the MIS-13 Interglacial according to HadCM3

The Climate of the MIS-13 Interglacial according to HadCM3

Temporal latitudinal-gradient dynamics and tropical instability of deep-sea species diversity

Sea Surface Temperature, Productivity, and Terrestrial Flux Variations of the Southeastern South China Sea over the Past 800000 Years (IMAGESMD972142)

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