446 research outputs found

    Joint diagnostic of the surface air temperature in southern South America and the Madden–Julian oscillation

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    The objective of this research is to explore the relationship between maximum and minimum temperatures, daily precipitation, and the Madden–Julian oscillation (MJO). It was found that the different phases of the MJO show a consistent signal on winter temperature variability and precipitation in southeastern South America. Additionally, this paper explores the spatial–temporal variations of mutual information and joint entropy between temperature and the MJO. A defined spatial pattern was observed with an increased signal in northeastern Argentina and southern Brazil. In the local mutual information analysis, periods in which the mutual information doubled the average values were observed over the entire region. These results indicate that these connections can be used to forecast winter temperatures with a better skill score in situations where both variables covary.Fil: Naumann, Gustavo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vargas, Walter Mario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Spatial Patterns of European droughts under a moderate emission scenario

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    Meteorological drought is generally defined as a prolonged deficiency of precipitation and is considered one of the most relevant natural hazards as the related impacts can involve many different sectors. In this study, we investigated the spatial patterns of European droughts for the periods 1981-2010, 2041-2070, and 2071-2100, focusing on the projections under a moderate emissions scenario. To do that, we used the outputs of the KNMI-RACMO2 model, which belongs to the A1B family and whose spatial resolution is 0.25°x0.25°. By means of monthly precipitation and potential evapo-transpiration (PET), we computed the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI) at12-month accumulation scale. Thereafter, we separately obtained drought frequency, duration, severity, and intensity for the whole of Europe, excluding Iceland. According to both indicators, the spatial drought patterns are projected to follow what recently characterized Europe: Southern Europe, who experienced many severe drought events in the last decades, is likely to be involved by longer, more frequent, severe, and intense droughts in the near future (2041-2070) and even more in the far future (2071-2100). This tendency is more evident using the SPEI, which also depends on temperature and consequently reflects the expected warming that will be highest for the Mediterranean area in Europe. On the other side, less severe and fewer drought events are likely to occur in Northern Europe. This tendency is more evident using the SPI, because the precipitation increase is projected to outbalance the temperature (and PET) rise in particular in Scandinavia. Regarding the mid-latitudes, the SPEI-based analyses point at more frequent drought events, while the SPI-based ones point at less frequent events in these regions.JRC.H.7-Climate Risk Managemen

    Variabilidad intraestacional de alta y baja frecuencia de la temperatura máxima y mínima diaria en Sudamérica. Estudio de la predictabilidad mediante la entropía condicional

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    Los pronósticos del tiempo y climáticos mejoran con el aumento de la habilidad de los modelos tanto dinámicos como probabilísticos en identificar situaciones de alto y bajo riesgo. Por esta razón el conocimiento de los procesos que intervienen en la identificación de situaciones con alto riesgo conlleva a una valoración en la información meteorológica por parte del usuario. Es por esto que la comprensión del funcionamiento del clima y su variabilidad requieren de diagnósticos específicos sobre la precipitación, las temperaturas y la circulación asociada a la misma. Esto adquiere más importancia a medida que la aplicación a diversos sistemas se hace necesaria. Por esto, este trabajo de Tesis tiene como objetivo general contribuir al conocimiento de la estructura de la temperatura máxima y mínima a escala diaria con las series de registros más largos en Sudamérica, que abarcan el período instrumental. Este conocimiento está dirigido a elaborar una climatología de valores diarios que permiten diagnosticar de forma objetiva y a través de síntesis matemática los procesos más importantes en las series de temperatura máxima y mínima diaria. Por lo tanto, el objetivo principal de este trabajo es obtener un análisis de la variabilidad climática especialmente dentro de la escala intraestacional en series de temperaturas extremas diarias en Sudamérica, para elaborar un diagnóstico y pronóstico objetivo con inferencia directa sobre el impacto

    Meteorological Droughts in Europe: Events and Impacts - Past Trends and Future Projections

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    Observational records from 1950 onwards and climate projections for the 21st century provide evidence that droughts are a recurrent climate feature in large parts of Europe, especially in the Mediterranean, but also in western, south-eastern and central Europe. Trends over the past 60 years show an increasing frequency, duration and intensity of droughts in these regions, while a negative trend has been observed in north-eastern Europe. With a changing climate, this tendency is likely to be reinforced during the 21st century, affecting a wide range of socioeconomic sectors. The report provides a detailed description of the characteristics of drought events (i.e. their frequency, duration, intensity, severity) across Europe, and their evolution over the period 1950 to 2012, as well as projections until the end of the 21st century. A pan-European database of meteorological drought events for the period 1950-2012 and of their related sectorial impacts was built and a framework developed that links drought severity to expected damages under present and future climate.Fil: Spinoni, Jonathan. European Commission Joint Research Centre; ItaliaFil: Naumann, Gustavo. European Commission Joint Research Centre; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vogt, Jürgen. European Commission Joint Research Centre; ItaliaFil: Barbosa, Paulo. European Commission Joint Research Centre; Itali

    Runoff properties of extreme discharges on Parana and Uruguay rivers

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    Climate variability in different spatial scales is a study area which has reached interest in application, especially during de last years. River discharges can be considered as a robust integrator of the properties of the basin; under these premises the goal of this work is to analyse flows from the Parana and Uruguay rivers in several gauge stations ´ and study the behavior of positive and negative anomalies and their extremes. The variable to be analysed was defined as the number of anomalies with the same sign per year. Results show that the structures are different for both rivers, which implies a different stochastic process. Identical representativeness was found between the anomaly series in each river. The risk estimation of extremes in both rivers indicates that it is possible to establish a decision model. Additionally, the series of annual number of anomalies presented a climatic jump in the seventies, for both rivers.Fil: Vargas, Walter Mario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bischoff, S.. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; ArgentinaFil: Naumann, Gustavo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marcuzzi, E.. Plan Nacional de Manejo del Fuego; Argentin

    Monitoring drought conditions and their uncertainties in Africa using TRMM data

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    The main objective of this study is to evaluate the uncertainties due to sample size associated with the estimation of the standardized precipitation index (SPI) and their impact on the level of confidence in drought monitoring in Africa using high-spatial-resolution data from short time series. To do this, two different rainfall datasets, each available on a monthly basis, were analyzed over four river basins in Africa-Oum er-Rbia, Limpopo, Niger, and eastern Nile-as well as at the continental level. The two precipitation datasets used were the Tropical Rainfall Measuring Mission (TRMM) satellite monthly rainfall product 3B43 and the Global Precipitation Climatology Centre full-reanalysis gridded precipitation dataset. A nonparametric resampling bootstrap approach was used to compute the confidence bands associated with the SPI estimation, which are essential for making a qualified assessment of drought events. The comparative analysis of different datasets suggests that for reliable drought monitoring over Africa it is feasible to use short time series of remote sensing precipitation data, such as those from TRMM, that have a higher spatial resolution than other gridded precipitation data. The proposed approach for drought monitoring has the potential to be used in support of decision making at both continental and subcontinental scales over Africa or over other regions that have a sparse distribution of rainfall measurement instruments.Fil: Naumann, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina. Joint Research Centre. Institute for Environment and Sustainability; ItaliaFil: Barbosa, P.. Joint Research Centre. Institute for Environment and Sustainability; ItaliaFil: Carrao, H.. Joint Research Centre. Institute for Environment and Sustainability; ItaliaFil: Singleton, A.. Joint Research Centre. Institute for Environment and Sustainability; ItaliaFil: Vogt, J.. Joint Research Centre. Institute for Environment and Sustainability; Itali

    Climate resilience of the top ten wheat producers in the Mediterranean and the Middle East

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    Wheat is the main staple crop and an important commodity in the Mediterranean and the Middle East. These are among the few areas in the world where the climate is suitable for growing durum wheat but also are among the most rapidly warming ones, according to the available scenarios of climate projections. How much food security and market stability in the Mediterranean and the Middle East, both depending on wheat production and its interannual variability, are going to be compromised by global warming is an overarching question. To contribute in addressing it, we use a recently established indicator to quantify crop production climate resilience. We present a methodological framework allowing to compute the annual production resilience indicator from nonstationary time series. We apply this approach on the wheat production of the 10 most important producers in the Mediterranean and the Middle East. Our findings shows that if no adaptation will take place, wheat production reliability in the Mediterranean and the Middle East will be threatened by climate change already at 1.5 °C global warming. Average climaterelated wheat production losses will exceed the worst past event even if the 2 °C mitigation target is met. These results call for urgent action on adaptation to climate change and support further efforts for mitigation, fully consistently with the Paris Agreement recommendations.Fil: Zampieri, Matteo. Joint Research Centre; ItaliaFil: Toreti, Andrea. Joint Research Centre; ItaliaFil: Ceglar, Andrej. Joint Research Centre; ItaliaFil: Naumann, Gustavo. Joint Research Centre; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Turco, Marco. Universidad de Murcia; EspañaFil: Tebaldi, Claudia. Joint Global Change Research Institute; Itali

    Annual green water resources and vegetation resilience indicators: Definitions, mutual relationships, and future climate projections

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    Satellites offer a privileged view on terrestrial ecosystems and a unique possibility to evaluate their status, their resilience and the reliability of the services they provide. In this study, we introduce two indicators for estimating the resilience of terrestrial ecosystems from the local to the global levels. We use the Normalized Differential Vegetation Index (NDVI) time series to estimate annual vegetation primary production resilience. We use annual precipitation time series to estimate annual green water resource resilience. Resilience estimation is achieved through the annual production resilience indicator, originally developed in agricultural science, which is formally derived from the original ecological definition of resilience i.e., the largest stress that the system can absorb without losing its function. Interestingly, we find coherent relationships between annual green water resource resilience and vegetation primary production resilience over a wide range of world biomes, suggesting that green water resource resilience contributes to determining vegetation primary production resilience. Finally, we estimate the changes of green water resource resilience due to climate change using results from the sixth phase of the Coupled Model Inter-comparison Project (CMIP6) and discuss the potential consequences of global warming for ecosystem service reliability.Fil: Zampieri, Matteo. Joint Research Centre; ItaliaFil: Grizzetti, Bruna. Joint Research Centre; ItaliaFil: Meroni, Michele. Joint Research Centre; ItaliaFil: Scoccimarro, Enrico. No especifíca;Fil: Vrieling, Anton. No especifíca;Fil: Naumann, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Toreti, Andrea. Joint Research Centre; Itali

    Soil moisture evaluation over the Argentine Pampas using models satellite estimations and in - situ measurements

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    Study region: The Pampas region is located in the central-east part of Argentina, and is one of the most productive agricultural regions of the world under rainfed conditions. Study focus: This study aims at examining how different Land Surface Models (LSMs) and satellite estimations reproduce daily surface and root zone soil moisture variability over 8 in-situ observation sites. The ability of the LSMs to detect dry and wet events is also evaluated. New hydrological insights for the region: The surface and root zone soil moisture of the LSMs and the surface soil moisture of the ESA CCI (European Space Agency Climate Change Initiative, hereafter ESA-SM) show in general a good performance against the in-situ measurements. In particular, the BHOA (Balance Hidrológico Operativo para el Agro) shows the best representation of the soil moisture dynamic range and variability, and the GLDAS (Global Land Data Assimilation System)-Noah, ERA-Interim TESSEL (Tiled ECMWF’s Scheme for Surface Exchanges over Land) and Global Drought Observatory (GDO)-LISFLOOD are able to adequately represent the soil moisture anomalies over the Pampas region. In addition to the LSM results, also the ESASM satellite estimated anomalies proved to be valuable. However, the LSMs and the ESA-SM have difficulties in reproducing the soil moisture frequency distributions. Based on this study, it is clear that accurate forcing data and soil parameters are critical to substantially improve the ability of LSMs to detect dry and wet events.Fil: Spennemann, P.C. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Servicio Meteorológico Nacional; Argentina Universidad Nacional de Tres de Febrero; ArgentinaFil: Fernández - Long, M.E. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Gattinoni, Natalia N. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; ArgentinaFil: Cammalleri, C. European Commission, Joint Research Centre; ItaliaFil: Naumann, G. European Commission, Joint Research Centre; Itali

    Global warming and human impacts of heat and cold extremes in the EU

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    During intense heatwaves in June and July 2019, all-time temperature records were broken in many locations in Europe. These events are projected to happen more frequently and become more intense with climate change. Projections show that the number of citizens in the EU and UK exposed to heatwaves will grow from 10 million/year (average 1981-2010) to nearly 300 million/year, or more than half the EU population, in a scenario with 3°C global average warming by the end of this century. In case of no adaptation this could result in 96,000 fatalities/year from extreme heat, compared to 2,750 annual deaths at present. Curbing global warming to 1.5°C would limit mortality from extreme heat to around 30,000 fatalities/year. The rise in exposure to and projected fatalities from extreme heat is most pronounced in southern Europe. Milder winters will reduce significantly exposure to and fatalities from extreme cold, nearly 10-fold with 3°C global average warming by the end of this century.JRC.E.1-Disaster Risk Managemen
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