Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials

Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed 300 ppm at any point during the last 800 000 years, East Antarctica was at least 3–4 C warmer than preindustrial (CO2 280 ppm) in each of the last four interglacials. During the previous three interglacials, this anomalous warming was short lived (3000 years) and apparently occurred before the completion of Northern Hemisphere deglaciation. Hereafter, we refer to these periods as “Warmer than Present Transients” (WPTs). We present a series of experiments to investigate the impact of deglacial meltwater on the Atlantic Meridional Overturning Circulation (AMOC) and Antarctic temperature. It is well known that a slowed AMOC would increase southern sea surface temperature (SST) through the bipolar seesaw and observational data suggests that the AMOC remained weak throughout the terminations precedingWPTs, strengthening rapidly at a time which coincides closely with peak Antarctic temperature. We present two 800 kyr transient simulations using the Intermediate Complexity model GENIE-1 which demonstrate that meltwater forcing generates transient southern warming that is consistent with the timing of WPTs, but is not sufficient (in this single parameterisation) to reproduce the magnitude of observed warmth. In order to investigate model and boundary condition uncertainty, we present three ensembles of transient GENIE-1 simulations across Termination II (135 000 to 124 000 BP) and three snapshot HadCM3 simulations at 130 000 BP. Only with consideration of the possible feedback of West Antarctic Ice Sheet (WAIS) retreat does it become possible to simulate the magnitude of observed warming

Sint-Amandsberg Verkortingstraat - Campo Santo

The implications are investigated of representing ocean gyre circulations by a diffusion term in the Stommel and Rooth box models of the thermohaline circulation (THC) in one and two hemispheres, respectively. The approach includes mostly analytical solution and study of the bifurcation structure, but also numerical integration and feedback analysis. Sufficient diffusion (gyre strength) eliminates multiple equilibria from either model, highlighting the need for accurate gyre circulation strength in general circulation models (GCMs) when considering the potential for abrupt climate change associated with THC shutdown.With diffusion, steady-state flow strength in the Rooth model depends on freshwater forcing (i.e., implied atmospheric water vapor transport) in both hemispheres, not only on that in the upwelling hemisphere, as in the nondiffusive case. With asymmetric freshwater forcing, two solutions (strong stable and weak unstable) are found with sinking in the hemisphere with stronger forcing and one solution with sinking in the other hemisphere. Under increased freshwater forcing the two solutions in the hemisphere with stronger forcing meet in a saddle-node bifurcation (if diffusion is sufficiently strong to prevent a subcritical Hopf bifurcation first), followed by flow reversal. Thus, the bifurcation structure with respect to freshwater forcing of the diffusive Rooth model of two-hemisphere THC is similar to that of the Stommel model of single-hemisphere THC, albeit with a very different dynamical interpretation. Gyre circulations stabilize high-latitude sinking in the Stommel model. In the Rooth model, gyre circulations only stabilize high-latitude sinking if the freshwater forcing is weaker in the sinking hemisphere than in the upwelling hemisphere, by an amount that increases with diffusion. The values of diffusion and freshwater forcing at which qualitative change in behavior occurs correspond to the range of the values used in and obtained with GCMs, suggesting that this analysis can provide a conceptual foundation for analyzing the stability of the interhemispheric THC, and also for the potential of the Atlantic THC to undergo abrupt change

RADIX: a minimal-resources rapid-access drilling system

Determining the expected age at a potential ice-core drilling site on a polar ice sheet generally depends on a combination of information from remote-sensing methods, estimates of current accumulation and modelling. This poses irreducible uncertainties in retrieving an undisturbed ice core of the desired age. Although recently perfected radar techniques will improve the picture of the ice sheet below future drilling sites, rapid prospective drillings could further increase the success of deep drilling projects. Here we design and explore a drilling system for a minimum-size rapid-access hole. The advantages of a small hole are the low demand for drilling fluid, low overall weight of the equipment, fast installing and de-installing and low costs. We show that, in theory, drilling of a 20mm hole to a depth of 3000m is possible in ~4 days. First concepts have been realized and verified in the field. Both the drill cuttings and the hole itself can be used to characterize the properties of the ice sheet and its potential to provide a trustworthy palaeo-record. A candidate drilling site could be explored in ~2 weeks, which would enable the characterization of several sites in one summer season

A stakeholder theory approach to creating value in higher education institutions

Purpose: This paper aims to empirically verify whether the development of improved relationships between higher education institutions (HEIs) and their stakeholders based on the principles of stakeholder theory creates more value. Design/methodology/approach: The methods involve a quantitative approach, with the data collection being carried out through a survey of 88 heads of HEIs in Brazil. The paper uses the Spearman’s correlation coefficient to analyze the data and test the hypotheses. Findings: The findings reinforce the arguments found in the stakeholder theory literature, in which relationships are based on the following principles: knowledge and information sharing, mutual trust, involvement in the decision-makin g process and alignment of stakeholders’ interests in the strategic planning process, all of which create more value for organizations. Practical implications: This study seeks to improve the knowledge of stakeholder theory in relation to HEIs. It identifies the stakeholder relationships that create the most value and have the potential to generate a sustainable competitive advantage. The results can help managers to improve their relationships with stakeholders and may encourage the implementation of practices and policies that consider stakeholders’ influence on the strategic direction of HEIs. Social implications: The studies present a social contribution by evidencing the importance of the development of best practices, processes and strategies in the management of educational institutions, which are important actors in the development of society. Originality/value: The originality of this paper is that it empirically tests the principles of stakeholder theory and their relationships with value creation for organizations in the higher education context. Whilst stakeholder theory has been explored in multiples contexts, there is a lack of studies addressing stakeholder management in HEIs

Integrating risks of climate change into water management

The Working Group II contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change critically reviewed and assessed tens of thousands of recent publications to inform about the assess current scientific knowledge on climate change impacts, vulnerability and adaptation. Chapter 3 of the report focuses on freshwater resources, but water issues are also prominent in other sectoral chapters and in the regional chapters of the Working Group II report as well as in various chapters of Working Group I. With this paper, the lead authors, a review editor and the chapter scientist of the freshwater chapter of the WGII AR5 wish to summarize their assessment of the most relevant risks of climate change related to freshwater systems and to show how assessment and reduction of those risks can be integrated into water management

Efectos del programa "Mi clase favorita" para la mejora de la producción oral del inglés en niños de primer grado de primaria de la IE FAP José A. Quiñones

Tesis para optar el título de Licenciada en EducaciónEsta tesis se propone mostrar que para lograr la habilidad en speaking (producción oral), una de las cuatro habilidades que conforman la enseñanza del idioma inglés (listening, speaking, reading, writing), es necesario que el docente conozca los principios que deben ser considerados para que esta competencia se haga posible. Enseñar el inglés no solo requiere que el docente posea dominio lingüístico sino también un dominio metodológico, de manera que propicie mejores aprendizajes en dicha lengua extranjera.Índice general Índice general .................................................................................................................. 2 Introducción .................................................................................................................... 4 CAPÍTULO I................................................................................................................... 7 PLANTEAMIENTO DEL PROBLEMA ..................................................................... 7 1.1. Descripción del problema.................................................................................... 7 1.1.1 Formulación del problema................................................................................ 10 1.2. Formulación de objetivos.................................................................................. 10 1.2.1. Objetivo general.................................................................................................. 10 1.2.2. Objetivos Específicos.......................................................................................... 11 1.3. Justificación.......................................................................................................... 11 1.4. Limitaciones de la investigación ........................................................................... 11 CAPÍTULO II .............................................................................................................. 13 MARCO TEÓRICO .................................................................................................... 13 2.1. Antecedentes de la investigación .......................................................................... 13 2.2 Bases teóricas........................................................................................................... 18 2.2.1. Recursos didácticos............................................................................................. 18 2.2.1.1 Clasificación de Recursos Didácticos. ............................................................. 19 2.2.1.2. Criterios para la clasificación de Recursos Didácticos................................. 21 2.2.2. Producción oral. .................................................................................................. 22 2.2.2.1. Tipos de situaciones de habla para los niños................................................. 24 2.2.2.2. Actividades comunicativas basadas en la precisión...................................... 24 2.2.2.3. Actividades comunicativas basadas en la fluidez.......................................... 24 2.2.3. Naturaleza del programa “Mi clase favorita”.................................................. 27 2.2.4. Objetivos del programa..................................................................................... 28 2.2.5. Formulación de las hipótesis............................................................................. 29 CAPÍTULO III.............................................................................................................. 30 METODOLOGÍA......................................................................................................... 30 3.1 Método de investigación ......................................................................................... 30 3.2 Diseño de investigación........................................................................................... 30 3.3 Sujetos de investigación.......................................................................................... 31 3.3.1 Criterios de inclusión y exclusión de la muestra ............................................... 31 3.4 Instrumentos............................................................................................................ 32 3.4.1 Programa “Mi clase favorita” ............................................................................ 32 3.4.2 Test de Cambrigde............................................................................................... 32 3.5 Procedimiento para la recolección de datos. ........................................................ 33 CAPÍTULO IV.............................................................................................................. 34 RESULTADOS ............................................................................................................. 34 4.1 Resultados................................................................................................................ 34 4.2 Resultados descriptivos .......................................................................................... 34 4.3 Contrastación de hipótesis ..................................................................................... 36 4.4 Análisis y discusión de resultados.......................................................................... 41 CAPÍTULO V ............................................................................................................... 44 CONCLUSIONES Y RECOMENDACIONES.......................................................... 44 5.1 Conclusiones....................................................................................................... 44 5.2 Recomendaciones.................................................................................................... 45 REFERENCIAS BIBLIOGRÁFICAS........................................................................ 46 ANEXO 1 DESARROLLO DEL PROGRAMA “MI CLASE FAVORITA”......... 49 ANEXO 2 ESTRUCTURA DEL TEST DE CAMBRIGDE ..................................... 62 ANEXO 3 RESULTADOS DE APLICACIÓN DEL PRE Y POST TEST ……….63Tesí

Oracle-based optimization applied to climate model calibration

In this paper, we show how oracle-based optimization can be effectively used for the calibration of an intermediate complexity climate model. In a fully developed example, we estimate the 12 principal parameters of the C-GOLDSTEIN climate model by using an oracle- based optimization tool, Proximal-ACCPM. The oracle is a procedure that finds, for each query point, a value for the goodness-of-fit function and an evaluation of its gradient. The difficulty in the model calibration problem stems from the need to undertake costly calculations for each simulation and also from the fact that the error function used to assess the goodness-of-fit is not convex. The method converges to a Fbest fit_ estimate over 10 times faster than a comparable test using the ensemble Kalman filter. The approach is simple to implement and potentially useful in calibrating computationally demanding models based on temporal integration (simulation), for which functional derivative information is not readily available

High-resolution aerosol concentration data from the Greenland NorthGRIP and NEEM deep ice cores

Records of chemical impurities from ice cores enable us to reconstruct the past deposition of aerosols onto polar ice sheets and alpine glaciers. Through this they allow us to gain insight into changes of the source, transport and deposition processes that ultimately determine the deposition flux at the coring location. However, the low concentrations of the aerosol species in the ice and the resulting high risk of contamination pose a formidable analytical challenge, especially if long, continuous and highly resolved records are needed. Continuous flow analysis, CFA, the continuous melting, decontamination and analysis of ice-core samples has mostly overcome this issue and has quickly become the de facto standard to obtain high-resolution aerosol records from ice cores after its inception at the University of Bern in the mid-1990s. Here, we present continuous records of calcium (Ca2+), sodium (Na+), ammonium (NH+4), nitrate (NO-3) and electrolytic conductivity at 1 mm depth resolution from the NGRIP (North Greenland Ice Core Project) and NEEM (North Greenland Eemian Ice Drilling) ice cores produced by the Bern Continuous Flow Analysis group in the years 2000 to 2011 (Erhardt et al., 2021). Both of the records were previously used in a number of studies but were never published in full 1 mm resolution. Alongside the 1 mm datasets we provide decadal averages, a detailed description of the methods, relevant references, an assessment of the quality of the data and its usable resolution. Along the way we will also give some historical context on the development of the Bern CFA system. The data is available in full 1 mm and 10-year-averaged resolution on PANGAEA (https://doi.org/10.1594/PANGAEA.935838, Erhardt et al., 2021