Use of expert elicitation to assign weights to climate and hydrological models in climate impact studies

Various methods are available for assessing uncertainties in climate impact studies. Among such methods, model weighting by expert elicitation is a practical way to provide a weighted ensemble of models for specific real-world impacts. The aim is to decrease the influence of improbable models in the results and easing the decisionmaking process. In this study both climate and hydrological models are analysed, and the result of a research experiment is presented using model weighting with the participation of six climate model experts and six hydrological model experts. For the experiment, seven climate models are a priori selected from a larger EURO-CORDEX (Coordinated Regional Downscaling Experiment – European Domain) ensemble of climate models, and three different hydrological models are chosen for each of the three European river basins. The model weighting is based on qualitative evaluation by the experts for each of the selected models based on a training material that describes the overall model structure and literature about climate models and the performance of hydrological models for the present period. The expert elicitation process follows a three-stage approach, with two individual rounds of elicitation of probabilities and a final group consensus, where the experts are separated into two different community groups: a climate and a hydrological modeller group. The dialogue reveals that under the conditions of the study, most climate modellers prefer the equal weighting of ensemble members, whereas hydrological-impact modellers in general are more open for assigning weights to different models in a multi-model ensemble, based on model performance and model structure. Climate experts are more open to exclude models, if obviously flawed, than to put weights on selected models in a relatively small ensemble. The study shows that expert elicitation can be an efficient way to assign weights to different hydrological models and thereby reduce the uncertainty in climate impact. However, for the climate model ensemble, comprising seven models, the elicitation in the format of this study could only re-establish a uniform weight between climate models.European Commission European Commission Joint Research Centre 69046

Improving the usability of climate services for the water sector: The AQUACLEW experience

In AQUACLEW (Advancing the QUAlity of CLimate services for European Water), a project funded by JPI Climate and the ERA-NET Consortium ‘European Research Area for Climate Services (ERA4CS), we examined different ways of improving the usability of existing Climate Services across Europe tackling key aspects in Climate Services improvement: user engagement, lack of resolution, uncertainties, and the need of an evaluation. The rationale of the project is based on an interactive process between service developers and users in seven study cases across Europe assessing the implications of Climate Service’ advancement in users’ decision-making process. A qualitative evaluation assessment allowed us to identify-four pillars when improving the quality of the climate services in the water sector: (1) Robustness, accounting for better quality of the service’ information in certain aspects; (2) Recruitment, understood as a need of involving users more actively in CS structures; (3) Reform, highlighting the possible need for changes in both the service structure and users mindsets; and (4) Reflection, as a process of continuous evaluation of the climate service during its life.Swedish Research Council FormasBMWFWSpanish GovernmentFrench National Research Agency (ANR)European Commission European Commission Joint Research CentreHelmholtz AssociationGerman Aerospace Centre (DLR)IFD 69046

Identificación y clasificación de ondulaciones en la línea de costa: base de datos europea

En la actualidad no se dispone de bases de datos con información sobre ondulaciones de media escala en la línea de costa que permitan hacer un análisis amplio de sus patrones de comportamiento. Así, el objetivo principal de este Proyecto Fin de Carrera ha sido identificar y caracterizar las ondulaciones de la línea de costa en Europa, e incluir esta información en una base de datos disponible tanto para los investigadores como para los gestores de la costa. Esta información ha sido analizada para extraer conclusiones sobre su comportamiento, y el caso español ha sido estudiado en detalle correlacionando las morfologías identificadas con los agentes marítimos.Proyecto Fin de Carrera de la Univ. de Granada, Grupo de Dinámica de Flujos Ambientales (TEP-209

Interaction of Swell and Sea Waves with Partially Reflective Structures for Possible Engineering Applications

In this work, we investigate the interaction between the combination of wind-driven and regular waves and a chamber defined by a rigid wall and a thin vertical semi-submerged barrier. A series of laboratory experiments were performed with different values of incident wave height, wave period, and wind speed. The analysis focuses on the effect of the geometry of the system characterized in terms of its relative submergence d/h and relative width B/L. Results show that for the case of d/h = 0.58 a resonant effect takes place inside the chamber regardless of the wind speed. Wind-driven waves have a higher influence on the variation of the wave period of the waves seaward and leeward of the plate, as well as on the phase lag. Results show that the amplification or reduction of the wave energy inside the chamber is closely related to the wave period as compared to the 1st order natural period of the chamber.A.L.L. is supported by the research group TEP-209 (Junta de Andalucía) and project AQUACLEW. Project AQUACLEW 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). During the preparation of the manuscript, A.L.L. was doing a research stay at the University of Parma (PhD cotutelle agreement) funded by the Campus of International Excellence of the Sea (CEIMAR) and the University of Granada

Storm characterization and simulation for damage evolution models of maritime structures

This paper presents a new approach to statistically characterize and simulate the wave climate under storm conditions. The methodology includes the joint selection of the parameters that identify storm events (significant wave height threshold, minimum storm duration and minimum interarrival time between consecutive storms) by means of hypothesis testing on the distribution functions of the number of storm events and the elapsing time between storms, providing an improved characterization of the parameters that define storm events. The main wave variables and their temporal dependence are characterized by non-stationary mixture distribution functions and a vector autoregressive model. This allows to adequately reproduce the random temporal evolution of storm events, crucial for the study of damage progression in maritime structures without the use of predefined geometries. The long-term time series of storm events and calm periods is obtained using copula functions which analyze the joint dependence of storm duration and interarrival time for separate climate intervals. The model is applied to hindcast data at a location of the Mediterranean sea close to the Granada coast in Spain to show its ability to reproduce wave storm conditions accounting for the time variability of the storminess. An example of application, using a large number of simulations and a damage progression model in a maritime structure, is presented.This work was performed within the framework of the project AQUACLEW and the research group TEP-209 (Junta de Andalucía). Project AQUACLEW is part of ERA4CS, and 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). MC wishes to acknowledge the funding provided by the Campus of International Excellence of the Sea (Cei-MAR). The authors would like to thank the MeteOcean group at the University of Genoa for providing the hindcast wave dataset used in this study (http://www3.di cca.unige.it/meteocean/hindcast.html)

Approaching Software Engineering for Marine Sciences: A Single Development Process for Multiple End-User Applications

Research software is currently used by a large number of scientists on a daily basis, and everything indicates that this trend will continue to increase in the future. Most of this scientific software is very often developed by the researchers themselves, who usually make it available to the rest of the scientific community. Although the relationship between science and software is unquestionably useful, it is not always successful. Some of the critical problems that scientists face include a lack of training in software development, a shortage of time and resources, or difficulty in effectively cooperating with other colleagues. Additional challenges arise in the context of increasingly common cross-cutting and multidisciplinary research. This often results in the developed software and code being slow, not reusable, lacks visibility and dissemination, and in the worst cases it is defective and unreliable. Therefore, a multidisciplinary framework is needed to meet the demands of both scientists and software engineers and handle the situation successfully. However, a multidisciplinary team is not always sufficient to solve this problem, and it is necessary to have links between scientists and developers: software engineers with a solid scientific background. This paper presents the approach used in the framework of the PROTOCOL project, and more particularly in the development of its applied software, in which a tool for the characterization of climate agents has been developed. The main guidelines of the development process include, among others, modularity, distributed control version, unit testing, profiling, inline documentation and the use of best practices and tools."Programa Iberoamericano de Ciencia y Tecnologia para el Desarrollo", CYTED (project PROTOCOL) 917PTE0538Spanish Ministry of Economy and Competitiveness PCIN-2017-10

Use of expert elicitation to assign weights to climate and hydrological models in climate impact studies

Various methods are available for assessing uncertainties in climate impact studies. Among such methods, model weighting by expert elicitation is a practical way to provide a weighted ensemble of models for specific real-world impacts. The aim is to decrease the influence of improbable models in the results and easing the decision-making process. In this study both climate and hydrological models are analysed, and the result of a research experiment is presented using model weighting with the participation of six climate model experts and six hydrological model experts. For the experiment, seven climate models are a priori selected from a larger EURO-CORDEX (Coordinated Regional Downscaling Experiment - European Domain) ensemble of climate models, and three different hydrological models are chosen for each of the three European river basins. The model weighting is based on qualitative evaluation by the experts for each of the selected models based on a training material that describes the overall model structure and literature about climate models and the performance of hydrological models for the present period. The expert elicitation process follows a three-stage approach, with two individual rounds of elicitation of probabilities and a final group consensus, where the experts are separated into two different community groups: a climate and a hydrological modeller group. The dialogue reveals that under the conditions of the study, most climate modellers prefer the equal weighting of ensemble members, whereas hydrological-impact modellers in general are more open for assigning weights to different models in a multi-model ensemble, based on model performance and model structure. Climate experts are more open to exclude models, if obviously flawed, than to put weights on selected models in a relatively small ensemble. The study shows that expert elicitation can be an efficient way to assign weights to different hydrological models and thereby reduce the uncertainty in climate impact. However, for the climate model ensemble, comprising seven models, the elicitation in the format of this study could only re-establish a uniform weight between climate models.This work was funded by the project AQUA-CLEW, which is part of ERA4CS (European Research Area for Climate Services), an ERANET (European Research Area Net-work) initiated by JPI Climate (Joint Programming Initiative) andfunded by Formas (Sweden); German Aerospace Center (DLR, Germany); Ministry of Education, Science and Research (BMBWF,Austria); Innovation Fund Denmark; Ministry of Economic Affairs and Digital Transformation (MINECO, Spain); and French National Research Agency with co-funding by the European Commission (grant no. 69046). The contribution of Philippe Lucas-Picher was supported by the French National Research Agency (future investment programme no. ANR-18-MPGA-0005). Rafael Pimentel acknowledges funding by the Modality 5.2 of the Programa Propio 2018 of the University of Córdoba and the Juan de la Cierva Incorporación programme of the Ministry of Science and Innovation (grant no. IJC2018-038093-I). Rafael Pimentel and María J. Polo are members of DAUCO (Unit of Excellence reference no. CEX2019-000968-M), with financial support from the Spanish Ministry of Science and Innovation and the Spanish State Research Agency, through the Severo Ochoa Centre of Excellence and María de Maeztu Unit of Excellence in research and development (R&D)

Experimental and analytical study of the hydrodynamics of swell and sea waves with partially reflective structures

The modeling of the interactions of different forcing agents, such as wind and waves, and maritime structures is a challenging problem with significant applications in coastal engineering leading to a usual implementation of complex numerical models. However, at the predesign stages of a project, there is need for fast, efficient and accurate analytical models that allow the search of the optimal configurations according to different design criteria. Furthermore, the studies regarding structural optimization, analytical and experimental, often do not consider the effect of wind forcing on the incident and reflected swell wave trains and the interaction with local wind-driven waves due to the complexity of the nonlinear interactions taking place. By means of Monte Carlo techniques, a large number of simulations were performed and applied to the analytical model to analyze the long-term performance of the structure and the uncertainty associated with the analysis.El modelado de las interacciones entre diferentes agentes climáticos, como el viento y el oleaje, con diferentes estructuras marítimas, es un desafío con aplicaciones muy importantes en ingeniería costera que normalmente conlleva el uso de modelos numéricos complejos. Sin embargo, en las etapas de prediseño de un proyecto, se necesitan modelos analíticos rápidos, eficientes y precisos que permitan la búsqueda de las configuraciones óptimas de acuerdo con diferentes criterios de diseño. Además, los estudios de interacción oleaje–estructura, analíticos y experimentales, a menudo no consideran el efecto del forzamiento del viento en el oleaje incidente y reflejado ni la interacción con mar de viento local debido a la complejidad de las interacciones no lineales de los procesos físicos. Mediante el uso de técnicas de Monte Carlo, se realizan una gran cantidad de simulaciones y se utilizan como condiciones de forzamiento al modelo analítico para analizar el rendimiento a largo plazo de la estructura y la incertidumbre asociada con el análisis.Tesis Univ. Granada.This thesis would have not been possible without the funding provided by the research group TEP-209 (Junta de Andalucía) and project AQUACLEW, part of ERA4CS, an ERA-NET initiative by JPI Climate co-funded by the European Union (Grant 690462). I wish to acknowledge the mobility grants given by the University of Granada PhD International Mobility Programme 2016/17, the Erasmus+ Programme KA1 (2017/18 – 2018/19) and the Campus of International Excellence of the Sea (CEIMAR)