64 research outputs found
Marine Sedimentary Record of benthic foraminifera geochemistry and bulk sediments geochemistry for ODP Site 846
No full textThe dataset contains information about sea surface and deep ocean variability over the past 5 million years. The dataset consists of benthic foraminifera d18O and alkenone-derived thermometry.
The benthic record is described in:
Mix, A. C., J. Le, and N. J. Shackleton (1995), Benthic foraminiferal stable isotope stratigraphy from Site 846: 0–1.8 Ma, Proc. Ocean Drill. Program Sci. Results, 138, 839–847.
Shackleton, N. J., Hall, M. A., & Pate, D. (1995). Pliocene stable isotope stratigraphy of ODP site 846. Proc. Ocean Drill. Program Sci. Results, 138, 337-356.
The sea surface record is described in:
Lawrence, K. T., Liu, Z. H., & Herbert, T. D. (2006). Evolution of the eastern tropical Pacific through Plio-Pleistocne glaciation. Science, 312(5770), 79-83.
The age model for the core was obtained through d18O alignement to the Benthic Stack of Lisiecki and Raymo (2005) using the HMM-Match alogrithm developed by Lin et al. (2014) as described in:
Khider, D., Ahn, S., Lisiecki, L. E., Lawrence, C. E., & Kienast, M. (2017). The Role of Uncertainty in Estimating Lead/Lag Relationships in Marine Sedimentary Archives: A Case Study From the Tropical Pacific. Paleoceanography, 32(11), 1275-1290
The data is formatted in the Linked Paleo Data (LiPD) format.</p
Three Metaphors of Exile in the Modern German Novel: Gehen, ging, gegangen by Jenny Erpenbeck, Ohrfeige by Abbas Khider, Das Mädchen mit dem Fingerhut by Michael Köhlmeier
No full textThe paper is divided into three parts. In the first one the most popular contexts of the research of the migrant literature are named: the actual debate about consequences of migrant policy and the figure of the author. In the second part three central metaphors in the novels of Erpenbeck, Khider and Köhlmeier are presented. These metaphors of exile are: disturbed time, lost life story, incomprehensible language. The third part contains an overview of the reception of the novels in Germany. The conventions of reading focus first of all on the two aforementioned non-fictional references (political context and author) without taking the metaphorical power of the texts into account. Thus the new migrant literature tends to become an equivalent for journalism and is read literally as a testimony of the author
Paleoceanography of the Indonesian Seas over the past 25,000 years
No full text2011-07-18The work presented in this dissertation focuses on the paleoceanography of the Indonesian Seas over the past 25,000 years; a region that plays a critical role in the global atmospheric and oceanic circulation. The modern oceanography of the Indonesian Seas is very complex due to the combined impact of the East Asian Monsoon, the Australian Monsoon, the migration of the Inter-Tropical Convergence Zone (ITCZ) and the El Niño Southern Oscillation, which is reflected in sea surface temperature (SST) and salinity (SSS) changes in this region on both intra- and interannual timescales. ❧ Therefore, in order to explore the impacts of these various climate systems on the paleoceanography of the Indonesian Seas, unbiased estimates of past SST/SSS are needed. One of the most common technique to infer past changes in SST is the measurement of Mg/Ca in the planktonic foraminifer Globigeriniodes ruber (white). When combined with the stable oxygen isotope (δ¹⁸O) measurements on the same foraminiferal sample, this technique allows to reconstruct past changes in δ¹⁸Osw, which varies linearly with SSS. This method assumes that the primary control on foraminiferal Mg/Ca is temperature, although several studies have shown that salinity can play an important role in the assimilation of Mg into biogenic calcite. Here I use foraminiferal Mg/Ca measurements from 165 core-top and sediment trap data with a global geographic distribution to show (1) that the Mg/Ca sensitivity to temperature is less than previously estimated (6%/°C vs 9%/°C) and (2) that although the effect of salinity on foraminiferal Mg/Ca is small between 32psu and 37psu (6%/psu), it needs to be taken into consideration to derive unbiased sea surface temperature and salinity estimates, especially on glacial/interglacial timescale. I propose a new set of calibration equations for estimating sea surface temperature and salinity in the 15-30°C/32-37psu range based on the paired measurements of Mg/Ca and δ¹⁸Oc on the same foraminiferal sample, which apply to the Indonesian Seas on glacial/interglacial timescales. ❧ These equations are then applied to eight published records from this region spanning the past 25,000 years. The unbiased estimates suggest a 4-4.5°C cooling in this region at the Last Glacial Maximum (LGM) as opposed to 2.5-3°C inferred from traditional Mg/Ca calibration equations. This cooling was accompanied by a region-wide local freshening, consistent with a more southerly position of the ITCZ and enhanced transport of 18O-depleted moisture from the Atlantic at the LGM. The record also suggests the presence of a temperature oscillation of ∼0.3-0.5°C during the deglaciation, coincident with the Northern Hemisphere Bølling-Allerød/Younger Dryas. This millennial temperature oscillation is accompanied by salinity changes, coincident with a change in the intensity of the summer East Asian Monsoon. SSSs reached a maximum in the early Holocene, supporting the hypothesis of a westward repositioning/expansion of the Western Pacific Warm Pool. SSSs then decreased over the Holocene, an observation consistent with a southerly displacement of the ITCZ. The flooding of the Sunda Shelf and the re-establishment of the “freshwater plug” in the southern Makassar Strait at 9.5ky B.P. is apparent in the SSS record, although there is no definite evidence for associated changes in heat transport from the Pacific to the Indian Ocean from the SST records. ❧ The Holocene has experienced several episodes of warming, culminating to the present warming trend. The last climate oscillation is the so-called Medieval Climate Anomaly/Little Ice Age (MCA/LIA). In order to investigate the hydrographic variability associated with the East Asian Monsoon, the relative mean position of the ITCZ and ENSO over this time interval, five high-resolution SST/SSS records from different locations within the Indonesian Seas are compared. The results suggest that hydrographic variability in this region was strongly associated with the MCA/LIA climate oscillation. Taken together, the records indicate a ∼0.5-1°C temperature change between the MCA and LIA. One of the records also indicates that, on average, the MCA was cooler than the 20th century, although several decades during the MCA show a warming comparable to that of the 20th century. The results also indicate a strengthening (weakening) of the East Asian Monsoon over the MCA (LIA), coincident with a northward (southward) migration of the ITCZ. However, the results do not indicate a preponderant role for ENSO in controlling the surface hydrographic variability found in this region over the past 2,000 years. ❧ In order to investigate the behavior of ENSO over the MCA/LIA, I used the stable isotope values of individual specimens of the thermocline-dwelling planktonic foraminifer Pulleniatina obliquiloculata from a sediment core collected from the Northern Makassar Strait. At this location, the δ¹⁸Oc produced by this foraminifer reflect the temperature and salinity variability that accompanies both eastern as well as central Pacific types of ENSO. Changes in ENSO strength/frequency were estimated by comparing the spread and symmetry of δ¹⁸Ocalcite values extracted from discrete time horizons in this sediment core. The spread of individual δ18Ocalcite values is interpreted to be a measure of the strength of both phases of ENSO while the symmetry of the δ¹⁸Ocalcite distributions is used to evaluate the relative strength/frequency of El Niño and La Niña events. In contrast to previous studies, robust and resistant statistics were used to quantify the spread and symmetry of the δ¹⁸Ocalcite distributions; an approach motivated by the relatively small sample size and the presence of outliers. The results indicate that ENSO has remained remarkably constant over the past millennium, with no systematic difference between the relatively warm conditions of the MCA and the cool conditions of the LIA. However, the MCA was characterized by stronger/more frequent La Niña than El Niño; an observation consistent with the medieval megadroughts documented from sites in western North America
"Ich triumphiere mit den Mitteln der Literatur"
No full textIm Zuge dieser Arbeit wird Abbas Khiders Werk auf die Fragen hin analysiert, welche Themenschwerpunkte er behandelt und auf welche Weise er diese in seine Erzählungen einbindet. Die Arbeit bildet nicht nur einen Beitrag zur noch spärlichen Khiderforschung, sondern soll auch einen Beitrag zur aktuellen sogenannten Migrationsdebatte darstellen. Die These lautet, dass Khider neue Perspektiven im Rahmen rezenter Diskurse eröffnet und die Diskussion seiner Werke zu einer weiteren Ausdifferenzierung dieser Diskurse beitragen kann. Vermittelst Subversion und Ironie exponiert der Autor Probleme in der deutschen ‚Migrationsgesellschaft‘ und stellt beispielsweise existierende Stereotype bloß. Er irritiert fixierte Positionen und macht sie angreifbar. Das Interesse dieser Arbeit gilt also den in Khiders Werk aufscheinenden subversiven Momenten. Die individuellen Stimmen der khiderschen Romanhelden werden im Rahmen aktueller Debatten situiert und mittels diverser Analysekategorien – oft an postkolonialen Theorien orientiert – diskutiert. Außerdem wird untersucht, wie sich Khider im Kontext der sogenannten Migrationsliteratur positioniert.In the course of this thesis the works of Abbas Khider are being analysed, addressing questions like, which key subjects he approaches and in which way he incorporates them into his narrations. The work not only forms a contribution to the yet scarce Khider-research, but also to the recent so-called migration debate. The theory is that Khider reveals new perspectives within the scope of recent discourses and that the discussion of his works can contribute to a further differentiation of these discourses. Through subversion and irony the author exposes problems in the German ‚migration society‘ and for instance unmasks existing stereotypes. He unsettles fixed positions and makes them corrodible. Hence the concern of this work is for the subversive moments that appear in Khider’s works. The individual voices of the Khiderian protagonists are being placed within the scope of recent debates and discussed through various categories of analysis – often guided by postcolonial theories. Furthermore it is being studied how Khider positions himself in the context of the so-called migration literature
The Geoscience Paper of the Future v2.0
No full textThis presentation was given at the EarthCube Annual Meeting held in San Diego, CA in June 2021. This presents an updated view of the Geoscience Paper of the Future first presented by Gil et al. (https://zenodo.org/doi/10.5281/zenodo.4744364).</p
AI, Violet Teaming, and Environmental Justice
No full textPresentation on how violet teaming can help scientists build AI system to ensure environmental justice.</p
LinkedEarth and 21st century Paleoclimatology - UCR Seminar
No full textPresentation given at UC Riverside on 01/23/2024. </p
LinkedEarth AGU Fall Meeting 2023
No full textThis poster presentation was given at the AGU Fall meeting in December 2023 in San Francisco, CA and summarizes the activities from LinkedEarth. </p
Meeting in the Middle: Using Abbas Khider’s book Deutsch für Alle (German for Everyone) as a lens into the accessibility of the German language
No full text36 p.The author discusses the ideas of Iraqi-German author Abbas Khider and his book Deutsch für Alle (German for Everyone). He writes “German for Everyone examines the accessibility of the German language and designs a new, easier-to-learn version of the German language. It treats the language like something that can be changed. The question of the function and accessibility of language has been of great interest to me because of my experiences as a German learner playing soccer. I tried to imagine Khider's new version of the German language in reality. How it would be to use Khider’s 'Neudeutsch' with my football teammates? For us, language was primarily a means of communication. This meant that we often incorrectly declined words, vocabulary from our mother tongues became confused. But we didn't care as long as we could understand each other, to work as a team. Sometimes the German players commented on how funny we sounded. It was like having our own version of the German language. Abbas Khider eliminates (or simplifies) many of the concepts that we as a team found difficult and I have therefore decided to continue this concept.
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