114 research outputs found

    Understanding Changes in Tropical Precipitation due to Climate Change

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    Projected precipitation changes due to increasing greenhouse gas concentrations exhibit considerable spatial structure with increases in the mid- to high-latitudes, and decreases in the subtropics. In the Equatorial regions, precipitation is pro- jected to increase over oceans, over Africa and over the Maritime Continent, but to decrease in the Amazon basin. The decrease in precipitation over the Amazon basin and increase over the Maritime Continent are both enhanced in response to plant physiological changes. The aim of this thesis is to identify basic controls on tropical precipitation change over ocean and land, with a particular focus on the zonal asymmetry in the Equatorial region and amplification of precipitation changes due to vegetation. We find that soil-moisture limits on evaporation and a teleconnection between Equatorial Africa and the Amazon basin contribute to the zonal asymmetry in rainfall changes over the two regions. When vegetation changes are included, the amplification of the drying over the Amazon basin is largely due to relatively weak local evapotranspiration, providing further evidence that loss of the Ama- zon rain forest could lead to strong decreases in rainfall. Furthermore, we find that tropical precipitation changes over a warm surface temperature anomaly are related to changes in the atmospheric energy budget, and that monsoon-type rainfall behaviour can be obtained even when the thermal inertias of land and ocean are the same, thus partly contradicting the historical view of monsoons as a large-scale land-sea breeze. Our findings are based on idealised Atmospheric General Circulation Model simulations with continental configurations ranging from flat rectangles to realistic continents with topography. Despite their simplicity, the simulations exhibit pre- cipitation changes similar to complex General Circulation Models, indicating that the mechanisms identified here contribute to tropical rainfall changes on Earth

    Times are changing, Bias isn't:A meta-meta-analysis on publication bias detection practices, prevalence rates, and predictors in industrial/organizational psychology

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    Effect misestimations plague Psychological Science, but advances in the identification of dissemination biases in general and publication bias in particular have helped in dealing with biased effects in the literature. However, the application of publication bias detection methods appears to be not equally prevalent across subdisciplines. It has been suggested that particularly in I/O Psychology, appropriate publication bias detection methods are underused. In this meta-meta-analysis, we present prevalence estimates, predictors, and time trends of publication bias in 128 meta-analyses that were published in the Journal of Applied Psychology (7,263 effect sizes, 3,000,000+ participants). Moreover, we reanalyzed data of 87 meta-analyses and applied nine standard and more modern publication bias detection methods. We show that (a) the bias detection method applications are underused (only 41% of meta-analyses use at least one method) but have increased in recent years, (b) those meta-analyses that apply such methods now use more, but mostly inappropriate methods, and (c) the prevalence of potential publication bias is concerning but mostly remains undetected. Although our results indicate somewhat of a trend toward higher bias awareness, they substantiate concerns about potential publication bias in I/O Psychology, warranting increased researcher awareness about appropriate and state-of-the-art bias detection and triangulation. Embracing open science practices such as data sharing or study preregistration is needed to raise reproducibility and ultimately strengthen Psychological Science in general and I/O Psychology in particular

    Response of tropical rainfall to reduced evapotranspiration depends on continental extent

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    This is the final version. Available from the American Meteorological Society via the DOI in this record The data for this publication is freely available on Zenodo: lowCO2 climate part 1: 10.5281/zenodo.5109451 - lowCO2 climate part 2: 10.5281/zenodo.5109484 - highCO2 climate part 1: 10.5281/zenodo.5109489 - highCO2 climate part 2: 10.5281/zenodo.5109494 - highCO2 climate part 3: 10.5281/zenodo.5109502Future projections of precipitation change over tropical land are often enhanced by vegetation responses to CO2 forcing in Earth System Models. Projected decreases in rainfall over the Amazon basin and increases over the Maritime Continent are both stronger when plant physiological changes are modelled than if these changes are neglected, but the reasons for this amplification remain unclear. The responses of vegetation to increasing CO2 levels are complex and uncertain, including possible decreases in stomatal conductance and increases in leaf area index due to CO2-fertilisation. Our results from an idealised Atmospheric General Circulation Model show that the amplification of rainfall changes occurs even when we use a simplified vegetation parameterisation based solely on CO2-driven decreases in stomatal conductance, indicating that this mechanism plays a key role in complex model projections. Based on simulations with rectangular continents we find that reducing terrestrial evaporation to zero with increasing CO2 notably leads to enhanced rainfall over a narrow island. Strong heating and ascent over the island trigger moisture advection from the surrounding ocean. In contrast, over larger continents rainfall depends on continental evaporation. Simulations with two rectangular continents representing South America and Africa reveal that the stronger decrease in rainfall over the Amazon basin seen in Earth System Models is due to a combination of local and remote effects, which are fundamentally connected to South America’s size and its location with respect to Africa. The response of tropical rainfall to changes in evapotranspiration is thus connected to size and configuration of the continents.Met OfficeNatural Environment Research Council (NERC)National Science FoundationUniversity of Exete

    Isca, v1.0: a framework for the global modelling of the atmospheres of Earth and other planets at varying levels of complexity

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    This is the final version of the article. Available from EGU via the DOI in this record.The accepted author manuscript, published in Geoscientific Model Development Discussions, is in ORE: http://hdl.handle.net/10871/31579Isca is a framework for the idealized modelling of the global circulation of planetary atmospheres at varying levels of complexity and realism. The framework is an outgrowth of models from the Geophysical Fluid Dynamics Laboratory in Princeton, USA, designed for Earth's atmosphere, but it may readily be extended into other planetary regimes. Various forcing and radiation options are available, from dry, time invariant, Newtonian thermal relaxation to moist dynamics with radiative transfer. Options are available in the dry thermal relaxation scheme to account for the effects of obliquity and eccentricity (and so seasonality), different atmospheric optical depths and a surface mixed layer. An idealized grey radiation scheme, a two-band scheme, and a multiband scheme are also available, all with simple moist effects and astronomically based solar forcing. At the complex end of the spectrum the framework provides a direct connection to comprehensive atmospheric general circulation models. For Earth modelling, options include an aquaplanet and configurable continental outlines and topography. Continents may be defined by changing albedo, heat capacity, and evaporative parameters and/or by using a simple bucket hydrology model. Oceanic Q fluxes may be added to reproduce specified sea surface temperatures, with arbitrary continental distributions. Planetary atmospheres may be configured by changing planetary size and mass, solar forcing, atmospheric mass, radiation, and other parameters. Examples are given of various Earth configurations as well as a giant planet simulation, a slowly rotating terrestrial planet simulation, and tidally locked and other orbitally resonant exoplanet simulations. The underlying model is written in Fortran and may largely be configured with Python scripts. Python scripts are also used to run the model on different architectures, to archive the output, and for diagnostics, graphics, and post-processing. All of these features are publicly available in a Git-based repository.This work was funded by the Leverhulme Trust, NERC (grant NE/M006123/1), the Royal Society (Wolfson Foundation), EPSRC, the Newton Fund (CSSP project), and the Marie Curie Foundation

    Isca, v1.0: a framework for the global modelling of the atmospheres of Earth and other planets at varying levels of complexity

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    This is the final version of the article. Available from EGU via the DOI in this record.The accepted author manuscript, published in Geoscientific Model Development Discussions, is in ORE: http://hdl.handle.net/10871/31579Isca is a framework for the idealized modelling of the global circulation of planetary atmospheres at varying levels of complexity and realism. The framework is an outgrowth of models from the Geophysical Fluid Dynamics Laboratory in Princeton, USA, designed for Earth's atmosphere, but it may readily be extended into other planetary regimes. Various forcing and radiation options are available, from dry, time invariant, Newtonian thermal relaxation to moist dynamics with radiative transfer. Options are available in the dry thermal relaxation scheme to account for the effects of obliquity and eccentricity (and so seasonality), different atmospheric optical depths and a surface mixed layer. An idealized grey radiation scheme, a two-band scheme, and a multiband scheme are also available, all with simple moist effects and astronomically based solar forcing. At the complex end of the spectrum the framework provides a direct connection to comprehensive atmospheric general circulation models. For Earth modelling, options include an aquaplanet and configurable continental outlines and topography. Continents may be defined by changing albedo, heat capacity, and evaporative parameters and/or by using a simple bucket hydrology model. Oceanic Q fluxes may be added to reproduce specified sea surface temperatures, with arbitrary continental distributions. Planetary atmospheres may be configured by changing planetary size and mass, solar forcing, atmospheric mass, radiation, and other parameters. Examples are given of various Earth configurations as well as a giant planet simulation, a slowly rotating terrestrial planet simulation, and tidally locked and other orbitally resonant exoplanet simulations. The underlying model is written in Fortran and may largely be configured with Python scripts. Python scripts are also used to run the model on different architectures, to archive the output, and for diagnostics, graphics, and post-processing. All of these features are publicly available in a Git-based repository.This work was funded by the Leverhulme Trust, NERC (grant NE/M006123/1), the Royal Society (Wolfson Foundation), EPSRC, the Newton Fund (CSSP project), and the Marie Curie Foundation

    Photoelectron circular dichroism of O 1ss-photoelectrons of uniaxially oriented trifluoromethyloxirane: Energy dependence and sensitivity to molecular configuration

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    The photoelectron circular dichroism (PECD) of the O 1s-photoelectrons of trifluoromethyloxirane(TFMOx) is studied experimentally and theoretically for different photoelectron kinetic energies. The experiments were performed employing circularly polarized synchrotron radiation and coincidentelectron and fragment ion detection using Cold Target Recoil Ion Momentum Spectroscopy. The corresponding calculations were performed by means of the Single Center method within the relaxed-core Hartree-Fock approximation. We concentrate on the energy dependence of the differential PECD of uniaxially oriented TFMOx molecules, which is accessible through the employed coincident detection. We also compare results for differential PECD of TFMOx to those obtained for the equivalent fragmentation channel and similar photoelectron kinetic energy of methyloxirane (MOx), studied in our previous work. Thereby, we investigate the influence of the substitution of the methyl-group by the trifluoromethyl-group at the chiral center on the molecular chiral response. Finally, the presently obtained angular distribution parameters are compared to those available in literature.Comment: 6 fig

    Pervasiveness of the IQ Rise: A Cross-Temporal Meta-Analysis

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    Background: Generational IQ gains in the general population (termed the Flynn effect) show an erratic pattern across different nations as well as across different domains of intelligence (fluid vs crystallized). Gains of fluid intelligence in different countries have been subject to extensive research, but less attention was directed towards gains of crystallized intelligence, probably due to evidence from the Anglo-American sphere suggesting only slight gains on this measure. In the present study, development of crystallized intelligence in the German speaking general population is assessed. Methodology/Principal Findings: To investigate whether IQ gains for crystallized intelligence are in progress in Germanspeaking countries, two independent meta-analyses were performed. By means of a cited reference search in ISI Web of Science, all studies citing test manuals and review articles of two widely-used salient measures of crystallized intelligence were obtained. Additionally, the electronic database for German academic theses was searched to identify unpublished studies employing these tests. All studies reporting participants mean IQ or raw scores of at least one of the two measures were included in the present analyses, yielding over 500 studies (.1,000 samples;.45,000 individuals). We found a significant positive association between years of test performance and intelligence (1971–2007) amounting to about 3.5 IQ points per decade. Conclusions/Significance: This study clearly demonstrates that crystallized IQ gains are substantial and of comparabl

    Probing the strength of infants' preference for helpers over hinderers: two replication attempts of Hamlin and Wynn (2011)

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    Several studies indicate that infants prefer individuals who act prosocially over those who act antisocially toward unrelated third parties. In the present study, we focused on a paradigm published by Kiley Hamlin and Karen Wynn in 2011. In this study, infants were habituated to a live puppet show in which a protagonist tried to open a box to retrieve a toy placed inside. The protagonist was either helped by a second puppet (the “Helper”), or hindered by a third puppet (the “Hinderer”). At test, infants were presented with the Helper and the Hinderer, and encouraged to reach for one of them. In the original study, 75% of 9-month-olds selected the Helper, arguably demonstrating a preference for prosocial over antisocial individuals. We conducted two studies with the aim of replicating this result. Each attempt was performed by a different group of experimenters. Study 1 followed the methods of the published study as faithfully as possible. Study 2 introduced slight modifications to the stimuli and the procedure following the guidelines generously provided by Kiley Hamlin and her collaborators. Yet, in our replication attempts, 9-month-olds’ preference for helpers over hinderers did not differ significantly from chance (62.5% and 50%, respectively, in Studies 1 and 2). Two types of factors could explain why our results differed from those of Hamlin and Wynn: minor methodological dissimilarities (in procedure, materials, or the population tested), or the effect size being smaller than originally assumed. We conclude that fine methodological details that are crucial to infants’ success in this task need to be identified to ensure the replicability of the original result

    Bis-[3]Ferrocenophanes with Central >E-E'<Bonds (E, E'=P, SiH) : Preparation, Properties, and Thermal Activation

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    Cover profile:10.1002/open.201900279.Invited for this month's cover picture are the groups of Professors Rudolf Pietschnig at the University of Kassel, Professor Dietrich Gudat at the University of Stuttgart and Professor Laszlo Nyulaszi at the Budapest University of Technology and Economics. The cover picture shows the thermally induced homolytic cleavage of the central P-P bond in a phosphorus-rich bis-ferrocenophane furnishing P-centered radicals (as evidenced by the computed spin-density highlighted in blue). The central P-6 unit in the title compound is a structural analog of the connecting unit in Hittorf's violet phosphorus, which links the orthogonally arranged tubular entities. A portrait of the German physicist Johann Wilhelm Hittorf is included. Read the full text of their Full Paper at 10.1002/open.201900182.Peer reviewe

    Suicide Seasonality: Complex Demodulation as a Novel Approach in Epidemiologic Analysis

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    Seasonality of suicides is well-known and nearly ubiquitous, but recent evidence showed inconsistent patterns of decreasing or increasing seasonality in different countries. Furthermore, strength of seasonality was hypothesized to be associated with suicide prevalence. This study aimed at pointing out methodological difficulties in examining changes in suicide seasonality. METHODODOLOGY/PRINCIPAL FINDINGS: The present study examines the hypothesis of decreasing seasonality with a superior method that allows continuous modeling of seasonality. Suicides in Austria (1970-2008, N = 67,741) were analyzed with complex demodulation, a local (point-in-time specific) version of harmonic analysis. This avoids the need to arbitrarily split the time series, as is common practice in the field of suicide seasonality research, and facilitates incorporating the association with suicide prevalence. Regression models were used to assess time trends and association of amplitude and absolute suicide numbers. Results showed that strength of seasonality was associated with absolute suicide numbers, and that strength of seasonality was stable during the study period when this association was taken into account.Continuous modeling of suicide seasonality with complex demodulation avoids spurious findings that can result when time series are segmented and analyzed piecewise or when the association with suicide prevalence is disregarded
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