76 research outputs found

    Benefits of simulating precipitation characteristics over Africa with a regionally-coupled atmosphere–ocean model

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    High-quality climate information at appropriate spatial and temporal resolution is essential to develop and provide tailored climate services for Africa. A common method to produce regional climate change data is to dynamically downscale global climate projections by means of regional climate models (RCMs). Deficiencies in the representation of the sea surface temperatures (SSTs) in earth system models (ESMs) and missing atmosphere–ocean interactions in RCMs contribute to the precipitation bias. This study analyzes the influence of the regional atmosphere–ocean coupling on simulated precipitation and its characteristics over Africa, and identifies those regions providing an added value using the regionally coupled atmosphere–ocean model ROM. For the analysis, the MPI-ESM-LR historical simulation and emission scenario RCP8.5 were dynamically downscaled with ROM at a spatial resolution of 0.22° × 0.22° for the whole African continent, including the tropical Atlantic and the Southwest Indian Ocean. The results show that reduced SST warm biases in both oceans lead to more realistic simulated precipitation over most coastal regions of Sub-Saharan Africa and over southern Africa to varying degrees depending on the season. In particular, the annual precipitation cycles over the coastal regions of the Atlantic Ocean are closer to observations. Moreover, total precipitation and extreme precipitation indices in the coupled historical simulation are significantly lower and more realistic compared to observations over the majority of the analyzed sub-regions. Finally, atmosphere–ocean coupling can amplify or attenuate climate change signals from precipitation indices or even change their sign in a regional climate projection

    Impact of ocean-atmosphere coupling on present and future Köppen-Geiger climate classification in Europe

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    The effect of air-sea coupling in the simulation of the European climate is assessed through a climate type classification that uses surface temperature and precipitation from a regional atmosphere-ocean coupled model and from its atmospheric component. The atmospheric setup in both models is the same, differing only in the representation of the oceanic fields. The simulations cover the present and future-time climate under the RCP8.5 CMIP5 scenario. Climate type distributions obtained from both coupled and uncoupled simulations are similar to those obtained from ERA5 for the 1976–2005 period. Both models simulate colder climate types for present-time in southern and northeastern regions compared to ERA5, possibly due to a weaker influence of the Atlantic circulation, and drier climate types in some western Mediterranean areas. Also, for present-time coupling leads to more humid winters (relatively drier summers) in some zones of north Spain and south France, and drier climates in some western Mediterranean spots. Based on simulations with these models under the RCP8.5 scenario, we find that by the end of the 21st century (2070–2099) the climate type distribution changes in more than 50% of the domain. While both models project the reduction of regions with cold climate types and the expansion of those with hot summers and hot arid climate types, these changes affect a larger area in the coupled simulation. These differences may be related to a drier signal in the coupled simulation, especially during summer, due to the influence of colder surface water in the North Atlantic Ocean and the Mediterranean Sea. Using a climate classification to evaluate the annual cycles of the simulated temperature and precipitation data provides a novel insight into the impact of air-ocean coupling on the representation of the climate, and consequently into the simulated impact on ecosystems and human activities in Europe

    Impact of air–sea coupling on the climate change signal over the Iberian Peninsula

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    In this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean

    Regionalización de la Península Ibérica e Islas Baleares desde el punto de vista eólico: aplicación al estudio de la evolución del recurso eólico en un escenario de cambio climático

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    Ponencia presentada en: IX Congreso de la Asociación Española de Climatología celebrado en Almería entre el 28 y el 30 de octubre de 2014.[ES]El impacto de la actividad humana en la evolución del clima ha sido fundamentado por numerosísimos estudios realizados por distintas disciplinas científicas, cuyos resultados han sido resumidos en las conclusiones de los informes de evaluación del IPCC. Y aunque la mayoría de los esfuerzos de la comunidad científica se han centrado en el estudio del impacto de los distintos escenarios de cambio climático en los campos de precipitación y temperatura, existe número creciente de publicaciones que estudian el efecto del cambio climático sobre el potencial eólico. En este trabajo estudiamos la evolución del potencial eólico en la Península Ibérica e Islas Baleares, hasta el 2050, simulado por el conjunto de cuatro RCMs utilizados en el marco del proyecto nacional ESCENA. Como un paso previo al estudio de la evolución de los vientos en la Península Ibérica e Islas Baleares, se dividió la Península en regiones con un comportamiento similar desde el punto de vista eólico, con el objeto de estudiar la evolución de los vientos de cada una de estas zonas como un todo. En este trabajo se estudia la evolución del recurso eólico en un ensemble de cuatro RCMs del proyecto ESCENA. Todos los modelos muestran una disminución del recurso hacia el año 2050, aunque la rapidez del cambio varía según las distintas regiones.[EN]The effects of the human activity in the climate change are supported by numerous studies of different scientific disciplines, and their results have been summed up in the IPCC documents. Although most of studies of the scientific community have been focused in the evolution of the temperature and precipitation fields, there are an increasingly number of studies about the evolution of wind power. These kinds of studies not only have interest from scientific point of view, they are interesting from energetic point of view too. A better knowledge of the wind speed variability we allow us to optimize better this resource. In addition, the wind power has become one of the main energy sources for some world areas as the Iberian Peninsula during the last decades. For example, in 2013 the wind power satisfied the 21,1% of the electricity demand of Spain, this fact made that the wind power was the main source of the electricity. As a previous study to the wind evolution of the Iberian Peninsula and Baleares Islands, the Iberian Peninsula was divided into regions to study the wind evolution of each region, to this end four RCMs of ESCENA project were used. All models show a reduction of wind power in 2050, but this reduction would be more dramatic for some areas than others

    Validación de los campos de velocidades del viento de la Península Ibérica simulados por los modelos climáticos del Proyecto ESCENA

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    Ponencia presentada en: XXXII Jornadas Científicas de la AME y el XIII Encuentro Hispano Luso de Meteorología celebrado en Alcobendas (Madrid), del 28 al 30 de mayo de 2012.En este trabajo se ha analizado la capacidad que tiene un emsemble, formado por cinco modelos climáticos regionales distintos centrados sobre la Península Ibérica de reproducir las variables climáticas más importantes que se usan para obtener el recurso eólico de una zona. Para ello se compararon entre sí los resultados obtenidos por los distintos modelos, y con bases de datos climatológicas, de reanálisis ERA_Interim y de mediciones ECA&D. Los modelos climáticos regionales elegidos fueron los del proyecto ESCENA (PROMES, dos versiones de WRF, MM5 y REMO) los cuales representan un buen ejemplo del estado del arte en modelización climática regional

    Climate change signal in the ocean circulation of the Tyrrhenian Sea

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    The Tyrrhenian Sea plays an important role in the winter deep water formation in the northwestern Mediterranean through the water that enters the Ligurian Sea via the Corsica Channel. Therefore, the study of the impact of the changes on the future climate on the Tyrrhenian circulation and its consequences represents an important issue. Furthermore, the seasonally dependent Tyrrhenian circulation, which is rich in dynamical mesoscale structures, is dominated by the interplay of local climate and the basin-wide Mediterranean circulation via the water transport across its major straits, and an adequate representation of its features represents an important modeling challenge. In this work we examine with a regionally coupled atmosphere–ocean model the changes in the Tyrrhenian circulation by the end of the 21st century under the RCP8.5 emission scenario, their driving mechanisms, and their possible impact on winter convection in the NW Mediterranean. Our model successfully reproduces the main features of the Mediterranean Sea and Tyrrhenian Basin present-day circulation. We find that toward the end of the century the winter cyclonic along-slope stream around the Tyrrhenian Basin becomes weaker. This weakening increases the wind work transferred to the mesoscale structures, which become more intense than at present in winter and summer. We also find that, in the future, the northward water transport across the Corsica Channel towards the Liguro-Provençal basin becomes smaller than today. Also, water that flows through this channel presents a stronger stratification because of a generalized warming with a freshening of upper and a saltening of intermediate waters. Both factors may contribute to the interruption of deep water formation in the Gulf of Lions by the end of the century

    Evaluación de la aceptabilidad de una galleta elaborada a base de harinas de tocosh (Solanlim Andigenum), trigo (Triticum aestivum) y quinua (Chenopodium quinoa), Chimbote-2021

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    La presente investigación tuvo por objetivo evaluar la aceptabilidad de una galleta elaborada a base de harinas de tocosh (Solanlim Andigenum) trigo (Triticum aestivum) y quinua (Chenopodium quinoa). La investigación fue de tipo aplicada y experimental y tomando en cuenta que se trabajó con diferentes materias primas para lograr un producto final se utilizó la técnica de diseño de mezclas de vértices extremos con el software Minitab el cual desarrolla la búsqueda de la composición óptima con “n” insumos utilizados. Los resultados obtenidos fueron: la caracterización de las materias primas, el desarrollo del proceso productivo, la elaboración de 9 formulaciones para la galleta, obtenidos por el software minitab, finalmente, se evaluó el nivel de aceptabilidad de la galleta a través de un panel semi entrenado aplicando un cuestionario de escala gráfica lineal. Concluyendo que la fórmula que optimiza la aceptabilidad corresponde a una composición de 76.18 % de trigo, 22.31 % de quinua y 1.5 % de tocosh. El análisis bromatológico de la galleta óptima presentó un total de 6.83 % de proteínas, 18,42 % de grasa, 8 % de humedad y 65.6 % de carbohidratos

    Demonstrating the asymmetry of the Indian Ocean Dipole response in regional earth system model of CORDEX-SA

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    An accurate representation of the Indian Ocean Dipole (IOD) is crucial for the reliable projection of Indian summer monsoon rainfall, making it necessary to improve the understanding of the response of the IOD in the warming climate. For the first time, a high-resolution regional earth system model (RESM) over the CORDEX-SA domain is used to investigate the IOD characteristics. The model performance is evaluated in simulating the IOD and associated mechanism. RESM shows a good resemblance in simulating IOD phases (positive and negative). However, the systematic discrepancy is observed in magnitude. Additionally, RESM well represented the positive IOD's inter-event variability. For example, the stronger event dominated by significant cold anomalies over Sumatra with enhanced westward-extended while a moderate event shows weak cooling confined to the region of Sumatra. Additionally, RESM shows potential to distinguish the ENSO and non-ENSO years with more remarkable skill in representing the spatial pattern of SST over IOD region during non-ESNO years than ENSO years. The RESM realistically simulated the IOD amplitude with greater skill than CMIP5/6 models reported in the earlier studies, indicating reliability towards the projection of the Indian summer monsoon. The weaker IOD-ENSO relationship is caused by producing the more significant number of IOD during non-ENSO years. Despite this reliable fidelity, IOD's slightly earlier peak is driven by the early establishment of low-level equatorial easterly wind. This study provided valuable insight into the IOD's different phases, responsible forcings, and limitations of the RESM in accounting for the role of internal climate variability that can be useful for further improvement in the model physics

    Impact of ocean–atmosphere coupling on future projection of Medicanes in the Mediterranean sea

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    Cyclones with tropical characteristics called medicanes (“Mediterranean Hur-ricanes”) eventually develop in the Mediterranean Sea. They have large harm-ful potential and a correct simulation of their evolution in climate projections is important for an adequate adaptation to climate change. Different studies suggest that ocean–atmosphere coupled models provide a better representation of medicanes, especially in terms of intensity and frequency. In this work, we use the regionally-coupled model ROM to study how air-sea interactions affect the evolution of medicanes in future climate projections. We find that under the RCP8.5 scenario our climate simulations show an overall frequency decrease which is more pronounced in the coupled than in the uncoupled con-figuration, whereas the intensity displays a different behaviour depending on the coupling. In the coupled run, the relative frequency of higher-intensity medicanes increases, but this is not found in the uncoupled simulation. Also, this study indicates that the coupled model simulates better the summer mini-mum in the occurrence of medicanes, avoiding the reproduction of unrealisti-cally intense events that can be found in summer in the uncoupled model
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