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Showing 1 to 18 of 18 for “"Eastern Equatorial Pacific"”.
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EASTERN EQUATORIAL PACIFIC PRODUCTIVITY VIA TWO GEOCHEMICAL PROXIES
… feedback in response to a dynamic climate. The eastern equatorial Pacific (EEP) is an ideal site for productivity studies due to its high levels of nutrients and deep upwelling. This research examines the phosphorous and barite geochemisty of four EEP sites while also comparing the sites’ …
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Selenium Distribution and Cycling in the Eastern Equatorial Pacific Ocean
<p>Oxygen minimum zones in oceanic waters have become increasingly important to the marine environment and society. Low oxygen waters affect not only the distribution and abundance of marine organisms, but also impact the solubility and transport of trace elements that are of biological importance, …
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Rare metal resources in polymetallic nodules from the Eastern Equatorial Pacific Ocean
… Clarion-Clipperton fracture zone (CCFZ) in the eastern equatorial Pacific is the area with the greatest interest in terms of metal resources in polymetallic nodules. The nodules are enriched (relative to crustal composition) in economically important metals such as Mn, Ni, Cu, Zn, and so-called …
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Reconstructing Surface Water Carbonate Ion Concentration Changes in the Eastern Equatorial Pacific Across Glacial Transitions
<p>Today, the eastern equatorial Pacific (EEP) plays a critical role in the global CO<sub>2</sub> budget as a major source of CO<sub>2</sub> to the atmosphere, but recent studies suggest the region may shift to a sink for atmospheric CO<sub>2</sub> under different climate states. Here, I focus on …
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Precipitation amount, altitude, and moisture trajectory effects on the stable isotopic composition of precipitation in the Galapagos Islands
… paleoclimate proxies, particularly in the eastern equatorial Pacific where stable water isotope observations from precipitation (δ18Op and δDp) are sparse. Here we present a new 28-month record of daily δ18Op and δDp from Santa Cruz, Galápagos. With a prior 13-year record of monthly …
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Orbital and Suborbital Climate Variability during the Pliocene Intensification of Northern Hemisphere Glaciation
… applied to deep-sea sediments in the equatorial oceans and the North Atlantic. In this<br/>way, I evaluate the forcing mechanisms, biogeochemical cycles and climate implications during<br/>the late Pliocene.<br/>In Chapter 2, palaeoproductivity is reconstructed in the western and …
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Physical Controls on Low and Mid-Latitude Marine Primary Productivity
… control of productivity over the subtropical and equatorial Pacific by directly comparing a wide range of contemporaneous metrics, drawn from the modern observational record, for interannual stratification and productivity variability. We find no correlation between the two in the subtropical …
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Pliocene-Pleistocene Radiolarian Investigations of the Equatorial Oceans
… Olduvai magnetosubchron (1.95-1.79Ma) of the equatorial Indo-Pacific Oceans. A number of radiolarian tools are used as palaeoceanographic proxies, including the recognition of distinct glacial and interglacial assemblages, which form the basis of a new Radiolarian Temperature Index (RTI), and …
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The Evolution of the El Niño-Southern Oscillation and Tropical Pacific Climate Across the Last Deglaciation
… the ENSO system and its relationship to tropical Pacific climate dynamics remains unclear. Although new paleoceanographic proxies have shown promise in in their ability to constrain past ENSO change, little is known about how ENSO varied in response to millennial-scale climate events over the last …
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The marine geochemistry of the rare earth elements
… respectively the Northwest Atlantic Ocean, the Eastern Equatorial Pacific Ocean and the Cariaco Trench, an anoxic basin. This data set represents the first detailed profiles of Pr, Tb, Ho, Tm and Lu in seawater, together with profiles of La, Ce, Nd, Sm, Eu, Gd and Yb. The first observations of …
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Zinc and cadmium in benthic foraminifera as tracers of ocean paleochemistry
… from the deep North Atlantic to the deep North Pacific. A "core top calibration" shows that Zn/Ca is controlled by bottom water dissolved Zn concentration and, like Cd/Ca and BalCa, by bottom water saturation state with respect to calcite Since Zn/Ca responds to a different range of saturation …
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Simple Models for Complex Tropical Dynamics
… Zone (ITCZ), the South Asian monsoon, Pacific and ENSO seasonality, the Walker Circulation, and the modeling of the tropical energy budget. We begin with an examination of tropical SSTs and the ITCZ under warming, finding that the Hadley cells weaken and tropical SST gradients decrease …
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Zinc and cadmium in benthic foraminifera as tracers of ocean paleochemistry
… from the deep North Atlantic to the deep North Pacific. A "core top calibration" shows that Zn/Ca is controlled by bottom water dissolved Zn concentration and, like Cd/Ca and BalCa, by bottom water saturation state with respect to calcite Since Zn/Ca responds to a different range of saturation …
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Reconstructing Tropical Pacific Climate Variability from Coral Archives
The tropical Pacific Ocean is a critical component of the climate system, and its mean state and variability are linked to effects across the globe. Our understanding of the area is limited by the scarcity of direct observations of important climatic variables prior to the mid-twentieth century, …
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A Coupled Bio-Optical and Mixed Layer Model for the Equatorial Pacific
… structure and heating of the upper ocean in the Equatorial Pacific Ocean. The bio-optical and mixed layer model for optically pure sea water was forced with climatological environmental conditions to provide a reference simulation for 140°W in the eastern Equatorial Pacific Ocean. This reference …
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Constraining Respired Carbon Storage in the Eastern Tropical Pacific Over the Last 25 Thousand Years Using Benthic Foraminiferal Boron/Calcium Ratios
<p>The storage of inorganic carbon in the deep Pacific Ocean is thought to play an important role in regulating both glacial-interglacial and millennial-scale atmospheric CO<sub>2</sub> concentrations (Broecker and Barker 2007; Sigman et al., 2010). A recent study by Loveley et al. (2017) showed …
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Eastern Tropical Pacific Climate And El Niño Variability During The Past Millennium
… paleoclimate records from the dynamically vital eastern equatorial Pacific Ocean (EEP) spanning the past millennium are sparse. This has limited our understanding of tropical Pacific dynamics, leaving questions regarding the source of ENSO variability unanswered. Here I seek to address some of …
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Exploring the Spatial Distribution of Marine Nitrogen Fixation Through Statistical Modeling, High-Resolution Observations and Molecular Level Characterization
… especially in high latitudes and the eastern equatorial Pacific, where observations are scarce. The large uncertainties in simulated N2 fixation and diazotrophs emphasized the need for a better understanding of the factors regulating N2 fixation and the physiology of …