1,720,961 research outputs found
ECHAM4.6-slab ocean model mid-Holocene simulation output
No full textClimate variables and water isotope output data from an ECHAM4.6-slab ocean model simulation of a mid-Holocene scenario
ECHAM4.6-slab ocean model pre-industrial simulation output
No full textClimate variables and water isotope output data from an ECHAM4.6-slab ocean model simulation of a pre-industrial scenario
Related Data for: The relative impacts of tropical Pacific teleconnections and local insolation on mid-Holocene precipitation over tropical South America
No full textThis dataset consists of simulation output generated using an atmospheric general circulation model, the ECHAM4.6. It includes monthly precipitation and annual precipitation δ¹⁸O fields from four ECHAM4.6 simulations. These experiments were designed to isolate the relative effects of tropical Pacific teleconnections and local mid-Holocene insolation forcing on tropical South American hydroclimate and serves as a supplement to Wong and Wang (2025). The dataset provides the raw model output for precipitation and precipitation δ¹⁸O, delivered in NetCDF format. Four experiments are included (please see the associated publication for a full methodological description of each experiment):
- Control: forced with observed monthly SSTs from 1979–2019
- NoENSO: climatological SSTs imposed over the tropical Pacific
- LNstate: mid-Holocene La Niña–like mean-state SST pattern applied in the tropical Pacific
- MHinsol: mid-Holocene orbital insolation and greenhouse gas concentrations applied.
The simulations were conducted in 2021–2022 using the isotope-enabled ECHAM model version 4.6. The model was run as an atmospheric general circulation model with prescribed sea-surface temperatures. It employs a hybrid sigma–pressure vertical coordinate system and was configured at T42 horizontal resolution (~2.8° × 2.8°) with 19 vertical atmospheric levels.
The dataset contains the processed model output, where one spin-up year has been removed, and the final 40 years of each experiment are included. Monthly precipitation fields were extracted directly from the model output, while annual precipitation δ¹⁸O values were derived from the model’s isotope module.
</p
Stable isotope (δ18O,δ13C) results of speleothems from Angelica Cave (central Brazil)
No full textHere we present a speleothem oxygen isotope (δ18O) and carbon isotope (δ13C) record from Angelica Cave in central Brazil (13.40°S, 46.23°W, ~585 m above sea level). The record is based on three stalagmite samples, AG1, AG2 and AG4. Ages of the samples were constrained by high-precision U-Th disequilibrium dating performed using a Thermo‐Fisher Scientific Neptune Plus multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). The three samples have a combined temporal coverage of 0.1-6.8 kyr BP, roughly spanning the mid-to-late Holocene. Stable isotope values were measured using a GasBench coupled to a Delta-V isotope ratio mass spectrometer (IRMS) system. Angelica δ18O and δ13C values display an overall relatively flat trend with time. The Angelica Cave underlies the core of the South Atlantic Convergence zone (SACZ). The δ18O record can therefore be interpreted as proxy for SACZ rainfall intensity. The relatively flat δ18O trend over the past 6.8 kyr BP suggests that SACZ rainfall intensity remained largely invariant during the mid-to-late Holocene, despite the rising South Hemisphere summer insolation and increasing monsoon strength in the core South American Summer Monsoon zone. The Angelica δ18O record also shows no clear expression of abrupt North Atlantic events, such as the Little Ice Age, Medieval Climate Anomaly and Bond Events
Uranium-Thorium dating results of speleothems from Angelica Cave (central Brazil)
No full textHere we present a speleothem oxygen isotope (δ18O) and carbon isotope (δ13C) record from Angelica Cave in central Brazil (13.40°S, 46.23°W, ~585 m above sea level). The record is based on three stalagmite samples, AG1, AG2 and AG4. Ages of the samples were constrained by high-precision U-Th disequilibrium dating performed using a Thermo‐Fisher Scientific Neptune Plus multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). The three samples have a combined temporal coverage of 0.1-6.8 kyr BP, roughly spanning the mid-to-late Holocene. Stable isotope values were measured using a GasBench coupled to a Delta-V isotope ratio mass spectrometer (IRMS) system. Angelica δ18O and δ13C values display an overall relatively flat trend with time. The Angelica Cave underlies the core of the South Atlantic Convergence zone (SACZ). The δ18O record can therefore be interpreted as proxy for SACZ rainfall intensity. The relatively flat δ18O trend over the past 6.8 kyr BP suggests that SACZ rainfall intensity remained largely invariant during the mid-to-late Holocene, despite the rising South Hemisphere summer insolation and increasing monsoon strength in the core South American Summer Monsoon zone. The Angelica δ18O record also shows no clear expression of abrupt North Atlantic events, such as the Little Ice Age, Medieval Climate Anomaly and Bond Events
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
