Statistical downscaling and attribution of air temperature change patterns in the Valencia region (1948–2011)

This study is based on the statistical downscaling and spatial interpolation of high-resolution temperatures (90 m) over the 1948–2011 period performed for the Valencia Region (east Iberian Peninsula) after considering local topographical factors in the fine-scale distribution of temperatures. The objective was to detect the areas that were potentially more vulnerable to air temperature change. This allowed the detection of local climate change patterns, which were analyzed and found to be consistent in spatial and temporal terms. These patterns indicate a more marked warming tendency in higher parts of reliefs and their slopes. However, this tendency is less pronounced in bottoms of valleys and on coastal plains, particularly for minimum temperatures, while the tendency for increasing maximum temperatures becomes more generalised. These patterns seem to connect well with regional changes in pressure fields, wind frequency, precipitation patterns and sea surface temperature.This work has been made possible thanks to the Foundation ‘Centro de Estudios Ambientales del Mediterráneo’ (CEAM) located in Valencia, Spain, the University Institute ‘Instituto Interuniversitario de Geografía’ of the University of Alicante, the University Department ‘Departamento de Geografía’ of the University of Valencia and the Spanish Ministry of Economy and Competitiveness through Project no. CGL2011-30433-C02 (Termed)

Impact of Initial Soil Temperature Derived from Remote Sensing and Numerical Weather Prediction Datasets on the Simulation of Extreme Heat Events

Extreme heat weather events have received increasing attention and has become of special importance as they can remarkably affect sectors as diverse as public health, energy consumption, water resources, natural biodiversity and agricultural production. In this regard, summer temperatures have become a parameter of essential interest under a framework of a hypothetical increase in the number of intense-heat conditions. Thus, their forecast is a crucial aspect bearing in mind a mitigation of the effects and impacts that these intense-heat situations could produce. The current work tries to reach a better understanding of these sorts of situations that are really common over the Western Mediterranean coast. An extreme heat episode that took place in the Valencia Region in July 2009 is analysed, based on the simulations performed with the Regional Atmospheric Modeling System (RAMS). This event recorded maximum temperatures exceeding 40 °C amply extended over the region besides reaching minimum temperatures up to 25.92 °C. We examine the role of improved skin and soil temperature (ST) initial conditions in the forecast results by means of different modelling and satellite-derived products. The influence of incorporating the Land Surface Temperature (LST) into RAMS is not found to produce a meaningful impact on the simulation results, independently of the resolution of the dataset used in the initial conditions of the model. In contrast, the introduction of the ST in lower levels, not only the skin temperature, has a more marked decisive effect in the simulation. Additionally, we have evaluated the influence of increasing the number of soil levels to spread deeper underground. This sensitivity experiment has revealed that more soil levels do not produce any meaningful impact on the simulation compared to the original one. In any case, RAMS is able to properly capture the observed patterns in those cases where a Western advection is widely extended over the area of study. This region’s variability in orography and in distances to the sea promotes the development of sea-breeze circulations, thus producing a convergence of two opposite wind flows, a Western synoptic advection and a sea-breeze circulation. As a result, the RAMS skill in those cases where a sea breeze is well developed depends on the proper location of the boundary and convergence lines of these two flows.This work has been funded by the Spanish Ministerio de Economía y Competitividad and the European Regional Development Fund (FEDER) through the project CGL2015-64268-R (MINECO/FEDER, UE), by the Regional Government of Valencia through the project PROMETEOII/2014/086 and by the Spanish Ministerio de Economía y Competitividad through the project CGL2011-30433-C02-02 (MINECO)

Reconstruction of thermal local signal from statistical downscaling (SD) through artificial neuronal network: detection of local patterns of change in Valencia Region (Spain) (1948-2011)

Para el área de la Comunidad Valenciana (España) se dispone de más de 300 series de temperatura diaria de las que sólo 3 cubren por completo el periodo 1948-2011, y una mayoría menos de la mitad de dicho periodo. El presente trabajo busca reconstruir todas las señales térmicas locales que faltan en el periodo completo 1948-2011 a partir del reanálisis NCEP/NCAR en dicho periodo. Para ello se realiza un downscaling estadístico con los datos observados por medio de una ANN. Ello ha permitido detectar patrones locales de cambio climático que han sido consistentes a lo largo del espacio y tiempo. Estos patrones señalan una tendencia mayor al calentamiento en las partes altas de los relieves y áreas de montaña, y menor en el fondo de los valles. El valor del estudio reside en la detección de las áreas potencialmente más vulnerables al cambio térmico, más que en una determinación exacta de una magnitud global de cambio térmico.For the area of Valencia (Spain) is available more than 300 daily temperature series of which only three cover completely the period from 1948 to 2011, and a majority less than half of that period. This work seeks to reconstruct all missing local thermal signals for the whole period 1948-2011 from the NCEP/NCAR reanalysis availability in that period. To do this, a statistical downscaling is performed with the observed data available through an ANN. This allowed us to detect local patterns of climate change that have been consistent over time and space. These patterns indicate substantially a greater warming tendency in the upper parts of the reliefs and mountain areas, and lower in the valley bottoms and lower lands. The value of the study lies primarily in identifying areas potentially more vulnerable to thermal change, rather than the accurate determination of a global magnitude of thermal change

Impact of Noah-LSM Parameterizations on WRF Mesoscale Simulations: Case Study of Prevailing Summer Atmospheric Conditions over a Typical Semi-Arid Region in Eastern Spain

The current study evaluates the ability of the Weather Research and Forecasting Model (WRF) to forecast surface energy fluxes over a region in Eastern Spain. Focusing on the sensitivity of the model to Land Surface Model (LSM) parameterizations, we compare the simulations provided by the original Noah LSM and the Noah LSM with multiple physics options (Noah-MP). Furthermore, we assess the WRF sensitivity to different Noah-MP physics schemes, namely the calculation of canopy stomatal resistance (OPT_CRS), the soil moisture factor for stomatal resistance (OPT_BTR), and the surface layer drag coefficient (OPT_SFC). It has been found that these physics options strongly affect the energy partitioning at the land surface in short-time scale simulations. Aside from in situ observations, we use the Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI) sensor to assess the Land Surface Temperature (LST) field simulated by WRF. Regarding multiple options in Noah-MP, WRF has been configured using three distinct soil moisture factors to control stomatal resistance (β factor) available in Noah-MP (Noah, CLM, and SSiB-types), two canopy stomatal resistance (Ball–Berry and Jarvis), and two options for surface layer drag coefficients (Monin–Obukhov and Chen97 scheme). Considering the β factor schemes, CLM and SSiB-type β factors simulate very low values of the latent heat flux while increasing the sensible heat flux. This result has been obtained independently of the canopy stomatal resistance scheme used. Additionally, the surface skin temperature simulated by Noah-MP is colder than that obtained by the original Noah LSM. This result is also highlighted when the simulated surface skin temperature is compared to the MSG-SEVIRI LST product. The largest differences between the satellite data and the mesoscale simulations are produced using the Noah-MP configurations run with the Monin–Obukhov parameterization for surface layer drag coefficients. In contrast, the Chen97 scheme shows larger surface skin temperatures than Monin–Obukhov, but at the expense of a decrease in the simulated sensible heat fluxes. In this regard, the ground heat flux and the net radiation play a key role in the simulation results.This research was funded by the Assistance Programmes of the University of Alicante “Programa de Redes-I3CE de calidad, innovación e investigación en docencia universitaria. Convocatoria 2018–2019. Alicante: Instituto de Ciencias de la Educación (ICE) de la Universidad de Alicante. Ref: [4334].” and “Programa de Redes-I3CE de calidad, innovación e investigación en docencia universitaria. Convocatoria 2020-21. Alicante: Instituto de Ciencias de la Educación (ICE) de la Universidad de Alicante. Ref: [5150].” as well as by Research Group VIGROB-116 (University of Alicante) and by the Spanish Ministerio de Ciencia e Innovación through the project PID2020-118797RB-I00/AEI

Cambios a fina escala de la aridez en la Comunidad Valenciana entre 1948 y 2011

Recientes avances en downscaling estadístico e interpolación espacial de temperaturas han resultado en la disponibilidad del dataset SDSITVC (Statistical Downscaling and Spatial Interpolation of Temperatures for the Valencian Community), con una resolución espacial de 90 m y periodo completo de 1948-2011, para la Comunidad Valenciana y áreas limítrofes. El presente trabajo busca relacionar dicha interpolación de temperaturas con otra de precipitaciones que, al igual que el SDSITVC, sea apta para el análisis de tendencias entre 1948 y 2011. Hasta la fecha no hay aún disponible una interpolación de precipitaciones con la misma resolución espacial, si bien se ha podido utilizar el dataset Spain02_v3, cuya resolución original es de 20km, como alternativa razonable para poder realizar una primera estimación espacial de cambios de la aridez en curso. Basándose en estudios previos sobre el SDSITVC que establecen la idoneidad de un periodo de referencia (1948-1979) y un periodo de testeo del cambio (1997-2011), el estudio determina cambios en la aridez entre los dos periodos según la aplicación de tres índices bioclimáticos simples y conocidos: Dantín – Revenga, Emberger, y Vernet. Se presenta una cartografía del cambio acontecido en dichos índices para la Comunidad Valenciana. Los resultados indican que ya habría habido cambios apreciables hacia aumentos de la aridez entre el periodo de referencia y el de testeo, particularmente hacia el interior y zonas altas.Recent advances in statistical downscaling and spatial interpolation of temperatures have resulted in the availability of the SDSITVC dataset (Statistical Downscaling and Spatial Interpolation of Temperatures for the Valencian Community). This complies a spatial resolution of 90 m and full 1948-2011 period, for the Valencian Community and surrounding areas. This paper seeks to relate this temperature interpolation with other for precipitation in the same way suitable for the analysis of trends between 1948 and 2011. To date there is no still available a spatial interpolation of precipitation with the same resolution of SDSITVC. While it has been possible to use the Spain02_v3 dataset, whose native resolution is 20km, as a reasonable alternative to a first spatial estimation of aridity changes in process. According to previous studies on the SDSITVC, a reference period (1948-1979) and a testing period (1997-2011) are established. The study determined changes in aridity between the two periods depending on the application of three simple and well-known bioclimatic indices: Dantin - Revenga, Emberger, and Vernet. A cartography of the change happened in these indexes for Valencian Community is presented. The results indicate that there would have already been substantial changes towards aridity increases between the reference and test periods, particularly towards the interior and upland areas.Este trabajo se ha realizado gracias al programa PROMETEOII (2014/086) de la Comunidad Valenciana, y el proyecto CGL2015- 64268-R (MINECO/FEDER, UE) del Ministerio de Economía y Competitividad y el FEDER

Implementation of non-local boundary layer schemes in the Regional Atmospheric Modeling System and its impact on simulated mesoscale circulations

This paper proposes the implementation of different non-local Planetary Boundary Layer schemes within the Regional Atmospheric Modeling System (RAMS) model. The two selected PBL parameterizations are the Medium-Range Forecast (MRF) PBL and its updated version, known as the Yonsei University (YSU) PBL. YSU is a first-order scheme that uses non-local eddy diffusivity coefficients to compute turbulent fluxes. It is based on the MRF, and improves it with an explicit treatment of the entrainment. With the aim of evaluating the RAMS results for these PBL parameterizations, a series of numerical simulations have been performed and contrasted with the results obtained using the Mellor and Yamada (MY) scheme, also widely used, and the standard PBL scheme in the RAMS model. The numerical study carried out here is focused on mesoscale circulation events during the summer, as these meteorological situations dominate this season of the year in the Western Mediterranean coast. In addition, the sensitivity of these PBL parameterizations to the initial soil moisture content is also evaluated. The results show a warmer and moister PBL for the YSU scheme compared to both MRF and MY. The model presents as well a tendency to overestimate the observed temperature and to underestimate the observed humidity, considering all PBL schemes and a low initial soil moisture content. In addition, the bias between the model and the observations is significantly reduced moistening the initial soil moisture of the corresponding run. Thus, varying this parameter has a positive effect and improves the simulated results in relation to the observations. However, there is still a significant overestimation of the wind speed over flatter terrain, independently of the PBL scheme and the initial soil moisture used, even though a different degree of accuracy is reproduced by RAMS taking into account the different sensitivity tests.This work has been funded by the Regional Government of Valencia through the project PROMETEOII/2014/086 and by the Spanish Ministerio de Economía y Competitividad through the projects CGL2013-46862-C02-1-P and CGL2015-64268-R

Confort climático, cambio climático y actividad turística en Alicante

Los rasgos climáticos son esenciales para comprender la vocación turística de los territorios. En el litoral mediterráneo desde los años sesenta del siglo XX hay una especialización en el producto turístico basado en los rasgos climáticos de verano (sol y playa). La provincia de Alicante es un destino turístico principal en el área mediterránea española y esta actividad representa el 18% de su PIB provincial. Las condiciones climáticas actuales proporcionan valores de confort climático, según el índice TCI, muy buenos o excelentes durante la temporada alta turística de verano; no obstante, el calentamiento térmico planetario proporciona valores de pérdida de excelencia climática hacia el final del presente siglo en los meses cálidos del año, lo que condicionará la adopción de medidas por parte del sector turístico y de la administración para intentar minimizar el impacto de la nueva realidad climática proyectada.Climatic characteristics are essential for understanding the tourist vocation of the territories. In the Mediterranean coast since the sixties of the twentieth century there is a specialization in the tourism product based on summer climate characteristics (“sun and beach”). Alicante province is a premier tourist destination in the Spanish Mediterranean area and this activity represents 18% of provincial GDP. Current weather conditions provide climate comfort values very good or excellent during peak summer tourist season, according to the TCI index. However, the global warming provides loss in the values of climate excellence towards the end of this century, especially in the warm months of the year, which will determine the action by the tourism sector and public administration to try minimize the impact of the new climate reality.Este trabajo se ha podido realizar gracias al programa para grupos de investigación de excelencia PROMETEOII (2014/086) de la Comunidad Valenciana, y el proyecto CGL2015- 64268-R (MINECO/FEDER, UE) del Ministerio de Economía y Competitividad y el FEDER

A component-based approximation for trend detection of intense rainfall in the Spanish Mediterranean coast

Rainfall behavior is a fundamental issue in areas with scarce and irregular amounts, such as the Spanish Mediterranean region. We identified 12 spatial patterns that characterized 899 torrential precipitation events (≥150 mm in 24 h) that occurred in the 3,537 rainy precipitation series in the period 1950–2020. Three of these components––eastern and ESE––showed positive and significant trends in their accumulated volumes. We then characterized the mean synoptic causes of the 10 most intense events in each component at both mean sea-level pressure and 500 hPa geopotential height, and also the integrated water-vapor transport between 1,000 and 300 hPa. We found a clear spatial distribution of the pluviometric effects related to unstable atmospheric situations (such as troughs and cut-off lows), and also to SW–SE advection fluxes that brought moist air from the Western Mediterranean. In particular, torrential rainfall in the Balearic Islands related more to E–NE advections than to southeastern ones. We also determined that the major parts of these components occurred in early autumn, especially in September and October. We expect these findings to help our understanding of the processes leading to catastrophic situations along the Spanish Mediterranean coast and to lead to improvements in early alert systems and management plans.The authors want to thank the Proyecto UTA-Mayor N° 5807–22 from the Universidad de Tarapacá, Chile. MLC, JMV, PS and OMR want to thank the Climatology Group (2017SGR1362, Catalan Government). RSN is partially supported by the Universidad Autónoma de Madrid (UAM) and the Comunidad de Madrid through project SI3-PJI-2021-00398, the Natural Hazards and Global Change research group from UAM, and the Government of Aragón through the “Program of research groups” (group H09_20R, “Climate, Water, Global Change, and Natural Systems”). JJM and MJE participation has been funded by the Spanish Ministerio de Ciencia e Innovación through the research project PID2020-118797RB-I00 (MCIN/AEI/10.13039/501100011033) and by Generalitat Valenciana through the research project PROMETEO/2021/016 (Conselleria d’Innovació, Universitats, Ciència i Societat Digital)

Recent advances in the interrelationship of vegetation and climate in Spain

Póster elaborado para el WCRP Open Science Conference celebrado en Denver del 24 al 28 de octubre de 201