Southern Spain Research Articles

Dendrochronological Analysis of Pinus pinea in Central Chile and South Spain for Sustainable Forest Management.

Pinus pinea is an important Mediterranean species due to its adaptability and tolerance to aridity and its high-quality pine nuts. Different forest types located in Mediterranean native and non-native environments provide the opportunity to perform comparative studies on the species' response to climate change. The aims of this study were to elucidate growth patterns of the species growing in native and exotic habitats and to analyze its response to climatic fluctuations, particularly drought, in both geographical contexts. Understanding stone pine (Pinus pinea) growth responses to climate variability in native and exotic habitats by comparing natural stands and plantations may provide useful information to plan adequate management under climate change. By doing so, we enhance the understanding of P. pinea's adaptability and provide practical approaches to its sustainable management. In this study, we reconstructed and compared the stem radial growth of seven stone pine stands, two in southern Spain and five in central-southern Chile, growing under different climatic conditions. We quantified the relationships between growth variability and climate variables (total rainfall, mean temperature, and SPEI drought index). Growth was positively correlated with autumn rainfall in plantations and with autumn-winter rainfall in natural stands. Growth was also enhanced by high autumn-to-spring rainfall in the driest Chilean plantation, whereas in the wettest and coolest plantation, such correlation was found in winter and summer. A negative impact of summer temperature was found only in one of the five Chilean plantations and in a Spanish site. The correlation between SPEI and tree-ring width indices showed different patterns between and within countries. Overall, exotic plantations showed lower sensitivity to climate variability than native stands. Therefore, stone pine plantations may be useful to assist in mitigating climate change.

Enhancing the building resilience in a changing climate through a passive cooling roof: A case study in Camas (Seville, Spain)

Renovating buildings is a crucial mission for the coming decades to combat energy inefficiencies and produce a resilient building stock. The inefficient thermal envelope has significant implications for occupants, especially for families lacking the financial resources to maintain a healthy and comfortable indoor environment. In scenarios where households cannot afford or utilize HVAC systems and high temperatures are more frequent, building retrofits should prioritize reducing heat loss in winter and passively lowering indoor temperatures in the cooling season. This work introduces a new solution to enhance the liveability of a social housing building in southern Spain by integrating a double-skin roof with a conventional retrofit strategy, which incorporates passive cooling techniques – night ventilation and an evaporative cooling system – for effective heat dissipation based on available commercial solutions. An extensive monitoring campaign was conducted over three years to evaluate the thermal comfort of occupants and the risk of overheating in naturally conditioned buildings before and after renovation following two impact assessment methods: real-time data-based and simulation-based. The real-time data-based method compared the indoor conditions of a dwelling with a conventionally retrofitted roof to one with a double-skin roof, indicating that the dynamic roof maintains a ceiling temperature lower than the air temperature throughout the summer while the conventional roof acts as a heating surface. On the other side, the simulation-based method compared the observed indoor conditions with a double-skin roof enabled during 2023 to the initial stage and a double-skin roof disabled scenario, using calibrated building energy models. The natural cooling roof solution almost eliminates the overheating events, leading to a reduction of 94.1% and 76.9% in discomfort degree-hours compared to the initial stage according to the ASHRAE adaptative and Fanger comfort models, respectively. Additionally, the results indicate that conventional retrofits can increase the risk of overheating when a cooling system is not considered. Integrating a cool roof solution requires only an extra implementation cost of 31€/m2 compared to a conventional solution, having an operational cost that represents less than 3% of the minimum monthly income in the social housing district.

Latiwitchellia (Grammoceratinae?, Ammonitina, Middle Jurassic); an eastern Pacific ammonite in the Betic Cordillera (Southern Spain)

Latiwitchellia (Grammoceratinae?, Ammonitina, Middle Jurassic); an eastern Pacific ammonite in the Betic Cordillera (Southern Spain)

Absence of Crimean-Congo hemorrhagic fever virus in wild lagomorphs and their ticks in Spanish Mediterranean ecosystems

Crimean-Congo hemorrhagic fever virus (CCHFV) is an emerging tick-borne pathogen in different European countries. Since 2013, clinical and fatality cases associated with CCHFV infection have been reported in humans in Spain. During the last few years, endemic circulation of this virus has been detected in ticks and wild ungulates in this country, but the role of other sympatric wild species in the sylvatic cycle of this multi-host virus remains poorly understood. The aims of the present study were to assess exposure to CCHFV in wild lagomorphs in southern Spain, a CCHFV endemic area, and to determine the presence of the virus in ticks feeding on these species. Serum samples from 473 European wild rabbits (Oryctolagus cuniculus) and 162 Iberian hares (Lepus granatensis), and 120 ticks feeding on 85 of these wild lagomorphs were collected on 133 hunting grounds between 2018/2019 and 2021/2022 hunting seasons. The presence of antibodies against CCHFV was assessed in all serum samples using a commercial ELISA, whereas ticks were tested for the presence of CCHFV-RNA by a multiplex RT-qPCR that detects all known genotypes of this virus. None of the 635 (0.0 %; 95 %CI: 0.0–0.6) lagomorphs tested had anti-CCHFV antibodies and CCHFV-RNA was not found in any of the 120 (0.0 %; 95 %CI: 0.0–3.0) ticks analyzed. To the best of the authors knowledge, this is the first epidemiological study conducted on CCHFV in Iberian hare worldwide. Our findings indicate absence of exposure to CCHFV in European wild rabbit and Iberian hare populations, as well as in their ticks, which suggests that they do not seem to play a relevant role in the epidemiology of CCHFV in Mediterranean ecosystems of southern Spain.

Individual and group emotional intelligence measurement of sex differences and invariance for individual (WLEIS-S) and group (WEIP-S) emotional intelligence measurement scales

Different international research groups focus on the study of socio-emotional resources and tools to facilitate adequate management of daily challenges and demands among teachers. This allows for better personal and professional performance. One of these resources that has attracted most attention in recent decades has been that of emotional intelligence. In this regard, the present study set out to analyse the psychometric properties of trait emotional intelligence as a construct. For this purpose, the study focused on two EI measurement instruments. One of the instruments (WLEIS-S) measures individual emotional intelligence and the other instrument (WEIP-S) measures group emotional intelligence. Against this background, the possible invariance of both scales with respect to the sex variable is analysed, as well as possible differences in the variables measured by the scales between sexes. To this end, 452 primary education teachers from Southern Spain filled in the WLEIS-S and WEIP-S tests. The results found in the factor analyses carried out with both instruments showed an excellent fit, as well as good internal consistency. Moreover, both instruments showed robust invariance, which indicates that both scales measure the emotional intelligence construct consistently for both women and men. No differences were found in the assessed latent variables between sexes. To conclude, this study shows psychometric evidence supporting the suitability of the WLEIS-S and WEIP-S scales for the accurate assessment of individual and group emotional intelligence in women and men in the teacher population.

Sampling of Culicoides with nontraditional methods provides unusual species composition and new records for southern Spain

BackgroundCulicoides midges have been well-studied in Spain, particularly over the last 20 years, mainly because of their role as vectors of arboviral diseases that affect livestock. Most studies on Culicoides are conducted using suction light traps in farmed environments, but studies employing alternative trapping techniques or focusing on natural habitats are scarce.MethodsIn the present study, we analyze Culicoides captured in 2023 at 476 sites in western Andalusia (southern Spain) using carbon dioxide-baited Biogents (BG)-sentinel traps across different ecosystems.ResultsWe collected 3,084 Culicoides midges (3060 females and 24 males) belonging to 23 species, including the new species Culicoides grandifovea sp. nov. and the first record of Culicoides pseudolangeroni for Europe. Both species were described with morphological and molecular methods and detailed data on spatial distribution was also recorded. The new species showed close phylogenetic relations with sequences from an unidentified Culicoides from Morocco (92.6% similarity) and with Culicoides kurensis. Culicoides imicola was the most abundant species (17.4%), followed by Culicoides grandifovea sp. nov. (14.6%) and Culicoides kurensis (11.9%). Interestingly, Culicoides montanus was the only species of the obsoletus and pulicaris species complexes captured, representing the first record of this species in southern Spain. A total of 53 valid Culicoides species have been reported in the area, with 48 already reported in literature records and 5 more added in the present study. Information on the flight period for the most common Culicoides species is also provided.ConclusionsTo the best of our knowledge, our study represents the most comprehensive effort ever done on nonfarmland habitats using carbon-dioxide baited suction traps for collecting Culicoides. Our data suggests that using carbon dioxide traps offers a completely different perspective on Culicoides communities compared with routinely used light traps, including the discovery of previously unrecorded species.Graphical

Effects of Authentic Leadership on Intrapreneurial Behaviour: A Study in the Service Sector of Southern Spain.

Employees currently face an increasingly demanding environment in terms of intrapreneurial behaviour due to the key role it plays in the survival of companies and the elimination of threats in the organisational environment. This paper investigates the antecedents of intrapreneurial behaviour in the service sector in southern Spain, analysing the relationships between it and authentic leadership, as well as the mediating role of practiced creativity, autonomy and meaningful work. This study uses a quantitative approach through the distribution of a questionnaire. A total of 333 employees completed the research questionnaire. The results show that although authentic leadership has a significant negative direct effect on intrapreneurial behaviour, it positively and significantly promotes it through practiced creativity and meaningful work. In contrast to the previous two mediations, the mediation of autonomy was not significant. This research provides empirical findings that can contribute to a better understanding of intrapreneurial behaviour by highlighting the importance of balanced, authentic leadership and offering guidance to organisations in designing a work climate that enhances organisational effectiveness.

Transferability of Empirical Models Derived from Satellite Imagery for Live Fuel Moisture Content Estimation and Fire Risk Prediction

Estimating live fuel moisture content (LFMC) is critical for assessing vegetation flammability and predicting potential fire behaviour, thus providing relevant information for wildfire prevention and management. Previous research has demonstrated that empirical modelling based on spectral data derived from remote sensing is useful for retrieving LFMC. However, these types of models are often very site-specific and generally considered difficult to extrapolate. In the present study, we analysed the performance of empirical models based on Sentinel-2 spectral data for estimating LFMC in fire-prone shrubland dominated by Cistus ladanifer. We used LFMC data collected in the field between June 2021 and September 2022 in 27 plots in the region of Andalusia (southern Spain). The specific objectives of the study included (i) to test previous existing models fitted for the same shrubland species in a different study area in the region of Madrid (central Spain); (ii) to calibrate empirical models with the field data from the region of Andalusia, comparing the model performance with that of existing models; and (iii) to test the capacity of the best empirical models to predict decreases in LFMC to critical threshold values in historical wildfire events. The results showed that the empirical models derived from Sentinel-2 data provided accurate LFMC monitoring, with a mean absolute error (MAE) of 15% in the estimation of LFMC variability throughout the year and with the MAE decreasing to 10% for the critical lower LFMC values (<100%). They also showed that previous models could be easily recalibrated for extrapolation to different geographical areas, yielding similar errors to the specific empirical models fitted in the study area in an independent validation. Finally, the results showed that decreases in LFMC in historical wildfire events were accurately predicted by the empirical models, with LFMC <80% in this fire-prone shrubland species.

Epidemiology of ANCA vasculitis in Northern Spain.

The incidence of anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) shows disparate results due to variable classification criteria and heterogeneous-population series. We aimed to estimate the incidence of AAV in a well-defined population with standardized classification criteria. Population-based study of AAV patients diagnosed from January 2000 to December 2023 in Cantabria, Northern Spain. Patients were classified according to ACR/EULAR 2022 into granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), or unclassified vasculitis if the criteria were not met. Eosinophilic granulomatosis with polyangiitis (EGPA) patients were not included. The annual incidence rates were estimated by cases over 1,000 000 (106) (95% CI) including overall AVV, type of AAV, sex, and year of diagnosis. A literature review was also performed. We included 152 (80/72 men; mean age; 70.6 ± 13.18 years) patients. They were classified as MPA (67; 44%), GPA (64; 42.2%), and unclassified vasculitis (21; 13.8%). Annual incidence was 13.4 (10-16.8)/106 [male 14.5 (10.5-18.5); female 12.1 (8.7-15.6)]. The Annual incidence of MPA was 5.9 (4-7.8)/106 and GPA 5.6 (3.9-7.3)/106. The mean Annual incidence increased from 6.1 (4.5-7.7)/106-16.5 (5.6-27.4)/106 in the last three years, particularly, in GPA from 2.3 (0.3-4.9)/106-8.2 (2-14.5)/106. The prevalence of AAV was 184.7 (181-188)/106. During a 20-year period we found that the incidence of AAV (GPA and MPA) in Northern Spain is higher than Southern Spain, but lower than Northern European countries. An increase in the incidence was observed in the last years.

Heavy Minerals Distribution and Provenance in Modern Beach and Fluvial Sands of the Betic Cordillera, Southern Spain

This study uses heavy detrital minerals to determine actualistic fluvial and beach sand provenance across the Betic Cordillera (Spain), along the coast from Almeria to Marbella. The Betic Cordillera, primarily composed of metamorphic rocks to the east, supply an assemblage dominated by almandine and graphite, with a longshore dispersal from Almeria to Malaga. Buergerite and hypersthene indicate the provenance of calcalkaline lavas east of Cabo de Gata. The western part of the Betic Cordillera, which comprises the Ronda Peridotite Complex, supplies a chromite and diopside assemblage, with a dispersal from Marbella to Algeciras. Considering these mineralogical suites, the effects of source rock compositions and weathering are evaluated. The heavy mineral species mirror the mineralogy of the source rocks of local outcrops and wider source terranes. The fluvial heavy mineral suites do not differ significantly from those in the beaches except for some unstable species. Unstable species such as olivine, pyroxene, and amphibole do not show evidence of loss because of elevated topography and semiarid climate, which do not affect heavy minerals. This contribution also evaluates the potential of some heavy detrital species as ideal pathfinders in searching for diamonds.

Who is who and why. Implications of tooth-marks identification at two sites in the Orce Basin Archaeological Zone (OBAZ; southern Spain)

The Orce Basin Archaeological Zone (OBAZ; Granada, Spain) is well known because it contains some of the most important Early Pleistocene archaeo-palaeontological sites for understanding the earliest human settlement in the westernmost part of Eurasia and its ecological context. Among those are Venta Micena (VM), Barranco León (BL) and Fuente Nueva 3 (FN3). The role played by the extinct Pachycrocuta brevirostris present at the OBAZ sites has long been recognised in the literature. However, little or nothing is known about the agency of the other documented carnivore species. Nevertheless, the development of technologies such as 3D modelling, geometric morphometrics, robust data modelling and artificial intelligence algorithms makes it possible to characterise a type of tooth mark (pits) and its assignment to a taxon. Moreover, such a combination of methodologies allows us to infer novel aspects related to the behaviour of carnivores, to establish interpretative differentiation between the carnivore agents at VM3 and BL, to point to the interactions among them and with Homo, and to review some proposals on the first human dispersal outside Africa.

Prevalence of childhood obesity in Spain and its relation with socioeconomic status and health behaviors: Population-based cross-sectional study

ObjectivesThis study aims to assess the current state of childhood overweight and obesity in Spain, and its relationship with socioeconomic status and health-related behaviors. MethodsPopulation-based cross-sectional observational study, based on the 2017 National Health Survey in minors in Spain. This study included all children surveyed who were aged 1–14 years. Childhood obesity was estimated from the z-score of the body mass index. ResultsThe study included 4882 children aged 1–14 years (mean 7.5). The prevalence of obesity was 18.6% (95% confidence interval [CI] 18.5–18.7), while 13.5% (95% CI 13.4–13.6) were overweight. These figures represent over a million children in Spain who are obese and nearly 750,000 who are overweight. A north–south geographic gradient was apparent, with higher prevalence of unhealthy body weight in southern Spain. Factors associated with childhood obesity were low socioeconomic status, poor diet and sedentarism, among others. ConclusionsChildhood overweight in Spain is strongly associated with socioeconomic status and other factors such as diet and sedentarism. Multidisciplinary public health interventions are needed to reduce this serious health problem in children.

Europe's orchard: The role of irrigation on the Spanish agricultural production

In the latter half of the twentieth century, Spanish agriculture witnessed sustained production growth, aligning with Western European levels after a period of lag in both production and productivity. This growth predominantly occurred in the warm, sunny provinces of southern and eastern Spain, which specialized in high-value crops such as fruits, vegetables, and olive oil. Various factors have been identified in the scientific literature as contributors to this transformation, including technological innovations, the internationalization of Spanish agriculture, domestic development, and advancements in irrigation. This paper aims to examine the impact of irrigation on Spanish agricultural production, focusing on the creation of regional and productive disparities since the mid-twentieth century. These diverse effects have been crucial in shaping the regional and product-specific specialization patterns that characterize the historical dynamism of Spanish agriculture. To that aim, we have compiled a comprehensive database containing detailed information on agricultural production values, irrigated and rainfed area and yields. The level of disaggregation of data, both in terms of production and regional breakdowns, enables us to identify specific regional and crop patterns. Additionally, this study highlights the significant and regionally varied transformations within the Spanish agricultural sector over the long term, which have had profound effects on rural areas.

NITRINET: A predictive model for nitrification in reclaimed water distribution in pressurised irrigation networks

In this work, a new model (NITRINET) to simulate nitrification processes in pressurised irrigation distribution networks fed with reclaimed water is developed and applied to the Tintín Irrigation District distribution network as case study (Montilla, southern Spain). The importance of this model relies on the fact that the nutrient chemical composition of reclaimed water varies spatially along the network. The water quality analyses carried out in the Irrigation District have shown that nitrate concentrations increase along the distribution network in contrast to the reduction observed in the ammoniacal forms. This confirms that nitrification processes occur inside the pipes. Thus, the model combines the hydraulic simulation of the distribution network and the modelling of nitrification processes to predict the concentration of ammoniacal nitrogen (NH4+-N) and nitric nitrogen (NO3--N) in water arriving at farms. This model is of great applicability to the irrigation sector, given that to carry out precision fertigation strategies and optimise the amount of fertiliser applied, it is necessary to determine the concentration of nutrients present in water arriving at farms. The nutrients that reclaimed water already carries must be considered when planning fertilisation. This allows for a reduction in the amount of fertiliser applied to the soil, which has a positive impact both on the environment and on farmers’ incomes. Simulations performed with NITRINET have shown promising results, predicting the concentration of NH4+-N and NO3--N in irrigation water with mean absolute errors of 1.49 mg·L−1 and 1.25 mg·L−1, respectively.

Indoor Environmental Quality and Effectiveness of Portable Air Cleaners in Reducing Levels of Airborne Particles during Schools’ Reopening in the COVID-19 Pandemic

Educational buildings tend to fail in the contagion containment of airborne infectious diseases because of the high number of children, for several hours a day, inside enclosed environments that often have inadequate indoor air quality (IAQ) conditions. This study aimed to assess indoor environmental quality and test the effectiveness of portable air cleaners (PACs) in alleviating airborne particle levels in schools of Central–Southern Spain during the period of reopening after the lockdown due to the COVID-19 outbreak. To accomplish this, three sampling campaigns were organized from September to December 2020 to consistently monitor temperature and relative humidity, carbon dioxide, and particulate matter in nineteen classrooms (seven school buildings). Results showed that although the recommendation of maintaining the windows open throughout the day seemed to be effective in promoting, in general, proper ventilation conditions (based on CO2 levels). For the colder campaigns, this practice caused notorious thermal comfort impairment. In addition, a great number of the surveyed classrooms presented levels of PM2.5 and PM10, attributable to outdoor and indoor sources, which exceeded the current WHO guideline values. Moreover, considering the practice of having the windows opened, the installation of 1 unit of PACs per classroom was insufficient to ensure a reduction in particle concentration to safe levels. Importantly, it was also found that children of different ages at different education levels can be exposed to significantly different environmental conditions in their classrooms; thus, the corrective measures to employ in each individual educational setting should reflect the features and needs of the target space/building.

Holocene biogeography of the southwestern European white‐toothed shrew (Crocidura iculisma, Eulipotyphla) through its fossil record

Abstract Crocidura iculisma (=C. suaveolens) is a shrew (Soricidae, Eulipotyphla) showing a fragmented distribution limited to the Iberian Peninsula, southern and western France and northwestern Italy. Although it has been in the Iberian Peninsula since the Middle Pleistocene, its biogeographical history remains poorly known. Here, we provide new data on Crocidura iculisma from the Castillejo del Bonete site (southern Spain) dated as 3.8–3.6 cal kyr BP. At the same time, we analyse changes in its geographic distribution based on its palaeontological record. We have reviewed thoroughly the Holocene record of Crocidura iculisma in southwestern Europe, considering independently the three time intervals according to the stages defined for this geological time series (Greenlandian, Northgrippian and Meghalayan). Whenever found together in fossil sites, the relative abundance of the two sympatric shrews of the genus Crocidura (Crocidura russula and Crocidura iculisma) was analysed. The data obtained concerning past distribution range and relative abundance were compared with the current status of the species in Iberia to interpret changes through time. The distribution range of the southwestern European white‐toothed shrew in the Iberian Peninsula has notably reduced over time until today. The occurrence at Castillejo del Bonete and other palaeontological records located beyond its current distribution range show that it was distributed in several areas of the eastern part and southern interior of Iberia, at least until the second half of the Meghalayan. Relative abundance patterns observed in the fossil assemblages suggest that competitive exclusion by Crocidura russula and climatic changes played a crucial role in driving the extirpation of Crocidura iculisma from a substantial portion of the Iberian Peninsula.

Analysis of HLA Alleles in Different Cohorts of Patients Infected by L. infantum from Southern Spain.

Leishmaniasis is an infectious disease caused by protozoa of the genus Leishmania, which is endemic in certain areas of Europe, such as southern Spain. The disease manifests in various clinical phenotypes, including visceral, cutaneous, mucosal, or asymptomatic leishmaniasis. This diversity in clinical outcomes may be influenced by the host immune response, with human leukocyte antigen (HLA) molecules playing a crucial role in determining susceptibility and progression of the infection. This study explores the association between specific HLA variants and Leishmania infantum infection. We recruited four cohorts: a control group, asymptomatic individuals, patients with symptomatic disease, and cohabitants of infected individuals. HLA typing was performed for all participants, followed by an association analysis with infection status and disease progression. Our findings indicate that the HLA-B*38 and HLA-C*03 alleles are associated with protection against L. infantum infection. These results contribute to a better understanding of the disease's progression, offer potential for new therapeutic approaches such as vaccines, and expand the existing knowledge in the literature.

Risk of invasion and disease transmission by the Australasian freshwater snail Orientogalba viridis (Lymnaeidae): a field and experimental study

BackgroundBiological invasions pose risks to the normal functioning of ecosystems by altering the structure and composition of several communities. Molluscs stand out as an extensively studied group given their long history of introduction by either natural or anthropogenic dispersal events. An alien population of the lymnaeid species Orientogalba viridis was first sighted in 2009 in southern Spain. In its native range (Australasian), this species is one of the main intermediate hosts of Fasciola hepatica, a major worldwide trematode parasite largely affecting humans, domestic animals and wildlife.MethodsWe collected field populations of O. viridis from its native (Malaysia) and invaded (Spain) ranges. We performed detailed morphoanatomical drawings of the species and screened for natural infection of parasites. Individuals were molecularly characterized using ITS2 for comparison with existing sequences in a fine phylogeography study. We founded experimental populations at two different conditions (tropical, 26 °C and temperate, 21 °C) to study the life-history traits of exposed and non-exposed individuals to different F. hepatica isolates.ResultsWe found a 9% natural prevalence of trematode infection (98% similarity with a sequence of Hypoderaeum conoideum [Echinostomatidae]) in the Spanish field population. The haplotypes of O. viridis found in our study from Spain clustered with Australian haplotypes. Experimental infection with F. hepatica was successful in both experimental conditions but higher in tropical (87% prevalence) than in temperate (73%). Overall lifespan, however, was higher in temperate conditions (mean 32.5 ± 7.4 weeks versus 23.3 ± 6.5) and survivorship remained above 70% during the first 20 weeks. In parasite-exposed populations, life expectancy dropped from an overall 37.75 weeks to 11.35 weeks but still doubled the time for initial cercariae shedding. Cercariae shedding started at day 23 post-exposure and peaked between days 53 and 67 with an average of 106 metacercariae per snail.ConclusionsWhether O. viridis will succeed in Europe is unknown, but the odds are for a scenario in which a major snail host of F. hepatica occupy all available habitats of potential transmission foci, ravelling the epidemiology of fasciolosis. This research provides a comprehensive understanding of O. viridis biology, interactions with parasites and potential implications for disease transmission dynamics, offering valuable insights for further research and surveillance.Graphical

Vacuum Loss Detection of PTC in CSP Plants via Temperature-Sensors

The efficient operation of a solar field is an essential factor for the commercial operation of a concentrating solar power (CSP) plant. In addition to predictive control for the highest possible constant outlet temperature at high mass flow, efficient operation also includes early detection of defective components and heat losses. This work presents a method for non-invasive heat loss detection as a strong indication for vacuum losses, based on measured operational data of Andasol III, an operating 50 MW parabolic trough collector (PTC) plant located in southern Spain. To detect vacuum losses via this method, mass flow rate and temperature reduction are determined separately for each individual loop via the analysis of a short-term temperature rise of the heat transfer fluid (HTF) during preheating. While the temperature reduction was measured directly, the mass flow was determined via the thermal time-of-flight (ToF) method using the same installed temperature sensors. By measuring thermal step responses during the preheating of the solar field at nighttime operation, the influence of fluctuating direct normal irradiance (DNI), misalignment of the absorber tubes and an offset in collector focus was circumvented. In the scope of the presented work, single loops were detected, which show a higher heat loss at lower mass flow rate and therefore have an increased probability of a higher vacuum loss. Better localization and early detection of these vacuum losses would allow the corresponding absorber tubes to be renewed at the economically and environmentally best time, improving the efficiency of the solar field and thus the entire CSP plant.

Changes in aerosol properties at the El Arenosillo site in Southern Europe as a result of the 2023 Canadian forest fires

From the beginning of May 2023 to the end of August 2023, the Northern Hemisphere experienced significant wildfire activity with the most widespread fires occurring in Canada. Forest fires in Canada destroyed more than 15.6 million hectares of forests. These wildfires worsened air quality across the region and other parts of the world. The smoke reached southern Europe by the end of June 2023. To better understand the consequences of such forest fires far from the site of origin, aerosol optical, microphysical and radiative properties were analyzed during this event for southern Europe using data from the Visible Infrared Imaging Radiometer Suite (VIIRS), TROPOspheric Monitoring Instrument (TROPOMI), and Aerosol Robotic Network (AERONET). TROPOMI aerosol index (AI) and the carbon monoxide (CO) product confirm that the smoke originated directly from these forest fires. AERONET data from the El Arenosillo site in southern Spain showed maximum aerosol optical depth (AOD) values on June 27 reached 2.36. Data on Angstrom Exponent (AE), aerosol volume size distribution (VSD), single scattering albedo (SSA), fine mode fraction (FMF), volume particle concentration, effective radius (REff), absorption AOD (AAOD), extinction AE (EAE) and absorption AE (AAE) showed that fine-mode particles with carbonaceous aerosols contribution predominated in the atmosphere above the El Arenosillo site. Direct aerosol radiative forcing (DARF) at the top (DARFTOA) and bottom of atmosphere (DARFBOA) were −103.1 and −198.93 Wm−2, respectively. The atmospheric aerosol radiative forcing (DARFATM) was found to be 95.83 Wm−2 and with a heating rate 2.69 K day−1, which indicates the resulting warming of the atmosphere.