A quality control procedure for long-term series of daily precipitation data in a semiarid environment

The availability of quality precipitation records in the current climate situation is of great importance in the scientifctechnical feld but also for the public institutions that manage the meteorological networks. This work has implemented a comprehensive spatial quality control procedure in the semiarid region of Andalusia (Southern Spain), using precipitation time series from 1947 stations from three meteorological networks: Spanish Meteorological Agency (AEMET), Agroclimatic Information Network of Andalusia (RIA), and Phytosanitary Information Alert Network (RAIF). The method consists of three consecutive steps: basic, absolute, and relative quality control processes. The latter step compares data from neighboring stations taking into account their proximity, height diference, and correlation, leading to a complete evaluation of each daily value. Finally, the quality of each year at each station can be declared as acceptable, good, or excellent. The automatic weather station networks RIA and RAIF gave absolute quality index Q above 85% for almost 87% of their stations, while only 57% of AEMET network reached this percentage. However, one of the longest AEMET datasets, San Fernando-Cádiz, obtained, except for 1 year, Q values over 90% in all available years for more than a century of measurements, since 1870 until 2000. From a total of more than 15 million daily records, almost 82% was fagged as correct. Despite the limitations of Andalusia region (low density of stations and its structural water defcit), the complete quality control procedure has been satisfactorily applied. Finally, related to the number of outliers, no temporal trend was found across the region.Peer ReviewedPostprint (published version

Multifractal structure of the monthly rainfall regime in Catalonia (NE Spain): Evaluation of the non-linear structural complexity

The complex non-linear regime of the monthly rainfall in Catalonia (NE Spain) is analyzed by means of the reconstruction fractal theorem and the multifractal detrended fluctuation analysis algorithm. Areas with a notable degree of complex physical mechanisms are detected by using the concepts of persistence (Hurst exponent), complexity (embedding dimension), predictive uncertainty (Lyapunov exponents), loss of memory of the mechanism (Kolmogorov exponent), and the set of multifractal parameters (Hölder exponents, spectral asymmetry, spectral width, and complexity index). Besides these analyses permitting a detailed description of monthly rainfall pattern characteristics, the obtained results should also be relevant for new research studies concerning monthly amounts forecasting at a monthly scale. On one hand, the number of necessary monthly data for autoregressive processes could change with the complexity of the multifractal structure of the monthly rainfall regime. On the other hand, the discrepancies between real monthly amounts and those generated by some autoregressive algorithms could be related to some parameters of the reconstruction fractal theorem, such as the Lyapunov and Kolmogorov exponents. The monthly rainfall regime in Catalonia, NE Spain, is analyzed by means of the fractal theory with the aim of improving the knowledge about its complex physical mechanism.Peer ReviewedPostprint (author's final draft

Rainfall disparity at monthly scale on Catalonia (NE Spain): dependence on geographic coordinates, altitude and distance to the Mediterranean coast

The rainfall regime in Catalonia, NE Spain, has a typical Mediterranean behaviour with irregular monthly amounts, sometimes the result of copious and intense torrential episodes for a few months, while for others precipitation is scarce. In addition, the varied topography of this region is related to significant rainfall differences between its different areas. The monthly precipitation from 97 stations spread throughout the territory, from 1950 to 2016, has allowed a detailed study of the spatial distribution of rainfall irregularity, based on the concept of disparity, D. The disparities have been calculated for every calendar month, to characterise the rainfall amount inter-annual oscillations, and also for all the consecutive months, to evaluate the rainfall disparity along the year. The spatial distribution of D has been obtained for all cases, showing a main general increase from North to South, and a secondary increase from West to East, in some months such as July. The winter months, especially January, have the highest values of D, which can reach the value of 2.0. The dependence of D on altitude and distance from the coast has also been analysed. The correlation is predominantly negative in both cases, although in some months, such as January, this correlation is not so clear. Additionally, the histograms of D show statistical characteristics, such as signs of a Gaussian distribution for some calendar months, as well as clear asymmetry in others. The obtained results could be interesting to detect the calendar months with the highest uncertainty on their expected rain amounts, contributing to a better knowledge of the complex structure of the rainfall Mediterranean regime.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was supported by the Spanish Ministry of Science, Innovation and Universities (grant PID2019-105976RB-I00 and grant AGL2017-87658-R).Postprint (published version

Análisis de escala simple de veinticinco años de registros de la red pluviométrica de Barcelona

El área metropolitana de Barcelona, de aproximadamente 100 Km2 de extensión, dispone de una red densa de pluviómetros de balancín que se empezó a instalar en 1983, y ha ido siendo gestionada desde entonces por diferentes empresas (CLABSA, Aqualogy, y actualmente BCASA). Se dispone de los registros 5-minutales de lluvia de una veintena de pluviómetros, a lo largo de 25 años de funcionamiento desde 1994 hasta 2019. A partir de estos registros de lluvia ha sido posible realizar un análisis de escala simple específico para cada pluviómetro, con el fin de poner de manifiesto las características, ligeramente diferentes, de la precipitación recogida en cada una de las zonas del área urbana.Peer ReviewedPostprint (published version

Time trends, irregularity and multifractal structure on the monthly rainfall regime at Barcelona, NE Spain, years 1786–2019

A long and complete series of monthly rainfall amounts corresponding to Barcelona city (Catalonia, NE Spain), exceeding two centuries (years 1786–2019), is analysed in detail. The obtained results of periodicity (annual scale), time trends (monthly, seasonal and annual scales), statistical distribution (seasonal and annual scale) and fractal/multifractal structures and self-similarity at monthly scale depict the complex structure of this pluviometric regime, which is characterized by moderate increasing and decreasing trends on rain amounts, varying from +0.08¿mm·year-1 (February) to -0.07¿mm·year-1 (September) and quite evident changes on the pluviometric trends at annual and seasonal scales when the rainfall data are analysed for segments of 50¿years from 1800 up to 2019. A good example could be the relevant change on the annual scale time trend, from +0.77¿mm·year-1 (years 1800–1850) to -0.17¿mm·year-1 (years 1950–2019). Clear evidences of decreasing pluviometry for spring, summer and autumn for the last segment (1950–2019) in comparison with the other three segments, including years 1800–1950, are also detected. Additionally, increasing rainfall patterns complexity, expected difficulties on monthly rainfall forecasting and the increasing irregularity of monthly amounts is also detected by interpreting fractal and multifractal results. Irregularity increases on the monthly rainfall series and on the rainfall regime complexity derived from multifractal parameters, could be associated with the very notable increase of CO2 emissions into the atmosphere, globally varying from 51.1¿×¿106 metric tonnes (year 1820) to 36.6¿×¿109 metric tonnes (year 2019) and the tropospheric concentration increasing from 280.8 ppm (year 1850) to 397.5 ppm (year 2014), being the probable relationship between tropospheric concentrations and changes on rainfall patterns the objective of future researches.Peer ReviewedPostprint (published version

Neural response to the observable self in social anxiety disorder

Background: Distorted images of the observable self are considered crucial in the development and maintenance of social anxiety. We generated an experimental situation in which participants viewed themselves from an observer's perspective when exposed to scrutiny and evaluation by others. Method: Twenty patients with social anxiety disorder (SAD) and 20 control subjects were assessed using functional magnetic resonance imaging (fMRI) during the public exposure of pre-recorded videos in which they were each shown performing a verbal task. The examiners acted as the audience in the experiment and rated performance. Whole-brain functional maps were computed using Statistical Parametric Mapping. Results: Robust activation was observed in regions related to self-face recognition, emotional response and general arousal in both study groups. Patients showed significantly greater activation only in the primary visual cortex. By contrast, they showed significant deactivation or smaller activation in dorsal frontoparietal and anterior cingulate cortices relevant to the cognitive control of negative emotion. Task-related anxiety ratings revealed a pattern of negative correlation with activation in this frontoparietal/cingulate network. Importantly, the relationship between social anxiety scores and neural response showed an inverted-U function with positive correlations in the lower score range and negative correlations in the higher range. Conclusions: Our findings suggest that exposure to scrutiny and evaluation in SAD may be associated with changes in cortical systems mediating the cognitive components of anxiety. Disorder severity seems to be relevant in shaping the neural response pattern, which is distinctively characterized by a reduced cortical response in the most severe cases

Anàlisi de les correlacions de Spearman entre els índexs ETCCDI de pluja hivernal i de tardor i els paràmetres de pol·len i espores a Bellaterra

Informe intern UPC - UAB - ICTAMentre el nombre de correlacions positives és molt superior que les negatives per la pluja hivernal que per l'anual a la majoria d’estacions aerobiològiques estudiades (Barcelona, Tarragona, Lleida i Manresa), a Bellaterra el nombre de correlacions negatives supera al de positives, és a dir, la raó positives/negatives és inferior a 1, igual que passava amb la pluja anual. A Girona aquesta raó també és inferior a 1, però el nombre de correlacions positives i negatives està molt més equilibrat. En aquest informe s’exposa un anàlisi més detallat del què passa a totes dues estacions, amb la intenció d’explicar aquest comportament inesperat, especialment a Bellaterra.Preprin

Hepatic steatosis in HIV/HCV co-infected patients: Correlates, efficacy and outcomes of anti-HCV therapy: A paired liver biopsy study

Background/Aims: Hepatic steatosis is caused by the complex interaction of host and viral factors, such as metabolic syndrome (MS), alcoholism and HCV genotype, and in HIV-HCV co-infected patients, antiretroviral therapy may also play a role. A large population of patients from the AIDS Pegasys Ribavirin International Co-infection Trial (APRICOT) had paired liver biopsies interpreted and graded for steatosis along with lipid measurements and anthropometric data. Methods: We analyzed these patients to determine the prevalence of steatosis, baseline factors associated with steatosis, effect of steatosis in HCV therapy efficacy and the impact of anti-HCV treatment on steatosis. Results: A total of 65/283 (23%) patients with paired biopsies were positive for steatosis. Patients with steatosis were significantly more likely to have HCV genotype 3, bridging fibrosis/cirrhosis, higher HCV RNA levels, increased triglycerides and lower cholesterol levels. The only different body measurement was neck circumference which was greater in patients with steatosis and significantly decreased from baseline during the study. Hip circumference was predictive of steatosis at baseline. Conclusions: Factors associated to the metabolic syndrome are important in co-infected patients. Treatment outcome affected steatosis in that viral eradication reduced steatosis in genotype 3 patients, but altogether steatosis did not affect efficacy of treatment in any genotype. © 2008 European Association for the Study of the Liver.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

On the convenience of the use of seasonal and monthly climatic indices in correlation studies

Moderately extreme rainfall is usually characterized by a set of standardized indicators, the ETCCDI precipitation indices, useful to compare climate changes on a global scale. These indices quantify information to reflect some aspects of the state of the environment by aggregating data in annual amounts, simplifying the study of complex phenomena. There is extensive use of these annual standardized indices in many fields, such as agriculture, human health and water resources. In particular, a complex correlation between rainfall annual indices and pollination/sporulation parameters can be observed, being useful to describe, in a global way, their joint variations and trends over time. However, a direct cause-effect relationship cannot be established due to the time limitations of the pollen and fungal spore release seasons. To investigate this possible causality, the modification of the standardized annual indices by calculating them only for the autumn or winter before the release seasons, or even for a specific previous month, can be essential.Peer ReviewedPostprint (published version

Autoregressive process of monthly rainfall amounts in Catalonia (NE Spain) and improvements on predictability of length and intensity of drought episodes

Advantages offered by a pluviometric network in Catalonia (NE Spain) have permitted a detailed analysis of the two primary results derived from the autoregressive ARIMA process applied to monthly rainfall amounts. The first was the spatial distribution of the necessary number of previous monthly amounts needed to predict the next amount. The second was the spatial distribution of discrepancies between the real recorded amount and those derived from the autoregressive process. The heterogeneous spatial distribution of both parameters of the ARIMA process is in accordance with the complex spatial distribution of the monthly rainfall regime in Catalonia and fractal/multifractal analyses of several monthly rainfall time series. The statistical distribution of monthly discrepancies also permits a prediction of the probable evolution at monthly scale of drought episodes in terms of length and accumulated rainfall deficit. The results of the ARIMA algorithm are characterised by a few cases of raingauges with remarkable differences (10-20¿mm/month) between real and autoregressive amounts, a predominant number of emplacements lowering 10¿mm/month and a not negligible number of cases with discrepancies lower than 5¿mm/month. In terms of percentages with respect to average monthly amounts, most of discrepancies do not exceed 15%, and only in a very few cases they are within the 20-40% range. It is also worth mentioning that the discrepancies between real and predicted drought lengths use to be no longer than one month. Results corresponding to monthly series recorded at two Earth Sciences observatories are described with more detail to illustrate the advantages offered by the ARIMA autoregressive process in the prediction of beginning, continuity and end of drought episodes.Postprint (author's final draft