Suchergebnisse

Ponencia presentada en: XI Congreso de la Asociación Española de Climatología celebrado en Cartagena entre el 17 y el 19 de octubre de 2018. ; [ES]Los libros de resúmenes anuales publicados por los sucesivos servicios meteorológicos de España contienen información no analizada hasta el presente. El proyecto CLICES (CLImate of the last CEntury in Spanish mainland) financiado por el Gobierno de España y la Unión Europea, tiene como objetivo inicial completar el rescate dela información referida a los promedios mensuales de temperatura máxima y mínima y totales de precipitación mensual, y emparejar esta información con los registros ya digitalizados en los archivos de la Agencia Estatal de Meteorología (AEMet). El objetivo final es elaborar una malla secular (1916-2015) maximizando el empleo de toda la información disponible. Las nuevas mallas no se obtendrán a partir de la reconstrucción e interpolación a partir de un número constante de observatorios, sino mediante la interpolación de los datos disponible en cada momento temporal, obteniendo así información continua en el tiempo y el espacio. Este método supone una ventaja frente a la reconstrucción individualizada de las series temporales, ya que permite trabajar con toda la información aprovechable, independientemente de la longitud de cada serie, si bien plantea problemas metodológicos derivados de que en cada campo mensual reconstruido variarán la localización y el número de observatorios empleados. En el presente trabajo se presentan los resultados iniciales relativos a la disponibilidad de información, incidiendo en aquella aportada por los Libros Resúmenes no incluida en los archivos de AEMet. ; [EN]The collection of books Resúmenes Anuales (Annual Books) published by the different meteorological agencies of Spain Government have information non-digitalized and converted to alphanumeric data. The national project (CLImate of the last CEntury in Spanish mainland) is funding by Spain government and European Union. The main objective of this project is to ...

We mapped – for the first time – the probability of occurrence of drought over Spain, with the overriding aim of improving current drought assessment, management and mitigation measures and strategies across the region. We employed two well-established drought indices: the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Drought characteristics (i.e. duration and severity) were characterised at 1-, 3-, 6- and 12-month, implying that drought event is attained only when the index values are lower than zero. We applied the extreme value theory to map drought hazard probability. Following this procedure, we tested different thresholds to generate the peak-over-threshold drought severity and magnitude series, besides evaluating different three-parametric distributions and thresholds to fit these series. Our results demonstrate that the Generalized Pareto distribution performs well in estimating the frequencies of drought magnitude and duration, with good agreement between the observed and modelled data when using upper percentiles to generate the peak-over-threshold series. Spatially, our estimations suggest a higher probability of extreme drought events in southern and central areas of Spain, compared to northern and eastern regions. Nevertheless, there are strong differences in drought probability estimations between drought indices (i.e. SPI and SPEI), as well as among drought timescales. ; This work was supported by the research projects CGL2014-52135-C03-01 and PCIN-2015-220 financed by the Spanish Commission of Science and Technology and FEDER, 1560/2015: Herramientas de monitorización de la vegetación mediante modelización ecohidrológica en parques continentales financed by the Red de Parques Nacionales, IMDROFLOOD financed by the Water Works 2014 co-funded call of the European Commission and INDECIS, which is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by MINECO with co-funding by the European Union 30 (Grant 690462).

Abstract. Drought is a major driver of vegetation activity in Spain, with significant impacts on crop yield, forest growth, and the occurrence of forest fires. Nonetheless, the sensitivity of vegetation to drought conditions differs largely amongst vegetation types and climates. We used a high-resolution (1.1 km) spatial dataset of the normalized difference vegetation index (NDVI) for the whole of Spain spanning the period from 1981 to 2015, combined with a dataset of the standardized precipitation evapotranspiration index (SPEI) to assess the sensitivity of vegetation types to drought across Spain. Specifically, this study explores the drought timescales at which vegetation activity shows its highest response to drought severity at different moments of the year. Results demonstrate that – over large areas of Spain – vegetation activity is controlled largely by the interannual variability of drought. More than 90 % of the land areas exhibited statistically significant positive correlations between the NDVI and the SPEI during dry summers (JJA). Nevertheless, there are some considerable spatio-temporal variations, which can be linked to differences in land cover and aridity conditions. In comparison to other climatic regions across Spain, results indicate that vegetation types located in arid regions showed the strongest response to drought. Importantly, this study stresses that the timescale at which drought is assessed is a dominant factor in understanding the different responses of vegetation activity to drought.

We present a long-term assessment of precipitation trends in Southwestern Europe (1850-2018) using data from multiple sources, including observations, gridded datasets and global climate model experiments. Contrary to previous investigations based on shorter records, we demonstrate, using new long-term, quality controlled precipitation series, the lack of statistically significant long-term decreasing trends in precipitation for the region. Rather, significant trends were mostly found for shorter periods, highlighting the prevalence of interdecadal and interannual variability at these time-scales. Global climate model outputs from three CMIP experiments are evaluated for periods concurrent with observations. Both the CMIP3 and CMIP5 ensembles show precipitation decline, with only CMIP6 showing agreement with long term trends in observations. However, for both CMIP3 and CMIP5 large interannual and internal variability among ensemble members makes it difficult to identify a trend that is statistically different from observations. Across both observations and models, our results make it difficult to associate any declining trends in precipitation in Southwestern Europe to anthropogenic forcing at this stage. ; This work was supported by the research projects CGL2017-82216-R, CGL2017-83866-C3-3-R and PCI2019-103631, financed by the Spanish Commission of Science and Technology and FEDER; CROSSDRO project financed by the AXIS (Assessment of Cross(X) - sectoral climate Impacts and pathways for Sustainable transformation), JPI-Climate co-funded call of the European Commission and INDECIS which is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (Grant 690462).