Synoptic weather patterns conducive to lightning-ignited wildfires in Catalonia

Wildfires cause substantial losses to socio-economic and natural assets, especially in Mediterranean climate regions. Despite human activity being the main cause of wildfires in Mediterranean European countries, lightning-ignited wildfires should also be considered a major disruptive agent as they can trigger large fires. In addition, recent studies on the potential climate change effects on wildfires pointed out that lightning-ignited wildfires may gain relevance in Mediterranean areas in the years to come. The present study analyses the synoptical weather patterns favouring lightning-ignited wildfires in Catalonia (NE Iberian Peninsula). Being able to identify areas with an elevated lightning-ignition survival at daily timescales would be of great assistance to wildfire management agencies, i.e. locating ignitions and potential holdover fires, preparing for days with multiple ignitions or routing detection flight paths. It is worth noticing that one of the reasons that lightning-caused wildfires are difficult to manage is that they can survive for several days after the ignition, emerging days later once surface vegetation becomes dry enough to support sustained combustion. For this reason, in a first step, a reliable lightning–wildfire association is needed to properly identify the date and time of the fire starter for each wildfire. Afterwards, the circulation types on the days of ignition are analysed. The study relies on a dataset of 870 lightning-ignited wildfires, gathered by the Forest Protection Agency of the autonomous government of Catalonia between 2005 and 2020. Lightning data were provided by the Lightning Location System operated by the Meteorological Service of Catalonia. Results show that lightning-ignited wildfires in Catalonia are related to a typical synoptic weather pattern dominated by a short-wave trough at 500 hPa, with three distinct associations: an Iberian thermal low (51 % of the fires), a northern flow (24 %) and prefrontal convection (13 %).Peer ReviewedPostprint (published version

Advanced seasonal predictions for vine management based on bioclimatic indicators tailored to the wine sector

The potential increase in the adoption value of seasonal forecasts is spotlighted in this paper by introducing observation-forecast blending for wine-sector indicators over the Iberian Peninsula. The predictions of six bioclimatic indicators (temperature and precipitation based) considered highly important from the perspective of wine-sector users were prepared for each month of the growing season and combined with previous observations as the indicator period progresses. The performance of this approach was then assessed with Pearson’s correlation coefficient and Fair Ranked Probability Skill Score (FRPSS). The results show a marked increase in the skill metrics during the growing season from the early combinations for all the indicators. This progressive improvement of the forecasting skill offers the users an opportunity to ponder anticipation and confidence in their decisions and, thus, facilitate the future uptake of seasonal forecasting in their decision planningThanks to all the partners of the project MED-GOLD (Turning climate-related information into added value for traditional MEDiterranean Grape, Olive and Durum Wheat food systems, agreement no. 776467), the project VITIGEOSS (Vineyard innovative tools based on the integration of Earth Observation services and in-field sensors, agreement no. 869565) and the project ASPECT (HE-101081460) funded by the European Union. The results contain modified Copernicus Climate Change Service information. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Thanks to SOGRAPE as the end-user for providing feedback in the co-development process. One of the coauthors, Raül Marcos-Matamoros, is a Serra Húnter Fellow. Finally, we thank the reviewers, whose comments helped improve the paper substantially.Peer Reviewed"Article signat per 11 autors/es: Chihchung Chou, Raül Marcos-Matamoros, Lluís Palma Garcia, Núria Pérez-Zanón, Marta Teixeira, Sara Silva, Natacha Fontes, Antonio Graça, Alessandro Dell'Aquila, Sandro Calmanti, Nube González-Reviriego"Postprint (published version

Earth System Model Evaluation Tool (ESMValTool) v2.0 – diagnostics for emergent constraints and future projections from Earth system models in CMIP

The Earth System Model Evaluation Tool (ESMValTool), a community diagnostics and performance metrics tool for evaluation and analysis of Earth system models (ESMs), is designed to facilitate a more comprehensive and rapid comparison of single or multiple models participating in the Coupled Model Intercomparison Project (CMIP). The ESM results can be compared against observations or reanalysis data as well as against other models including predecessor versions of the same model. The updated and extended version (v2.0) of the ESMValTool includes several new analysis scripts such as large-scale diagnostics for evaluation of ESMs as well as diagnostics for extreme events, regional model and impact evaluation. In this paper, the newly implemented climate metrics such as effective climate sensitivity (ECS) and transient climate response (TCR) as well as emergent constraints for various climate-relevant feedbacks and diagnostics for future projections from ESMs are described and illustrated with examples using results from the well-established model ensemble CMIP5. The emergent constraints implemented include constraints on ECS, snow-albedo effect, climate–carbon cycle feedback, hydrologic cycle intensification, future Indian summer monsoon precipitation and year of disappearance of summer Arctic sea ice. The diagnostics included in ESMValTool v2.0 to analyze future climate projections from ESMs further include analysis scripts to reproduce selected figures of chapter 12 of the Intergovernmental Panel on Climate Change's (IPCC) Fifth Assessment Report (AR5) and various multi-model statistics.This research has been supported by the Horizon 2020 Framework Programme (CRESCENDO (grant no. 641816), 4C (grant no. 821003), and IS-ENES3 (grant no. 824084)), the Copernicus Climate Change Service (C3S) (Metrics and Access to Global Indices for Climate Change Projections (MAGIC)), the Federal Ministry of Education and Research (BMBF) (CMIP6-DICAD), the European Space Agency (ESA Climate Change Initiative Climate Model User Group (ESA CCI CMUG)) and the Helmholtz Association (Advanced Earth System Model Evaluation for CMIP (EVal4CMIP)).Peer Reviewed"Article signat per 13 autors/es: Axel Lauer, Veronika Eyring, Omar Bellprat, Lisa Bock, Bettina K. Gier, Alasdair Hunter, Ruth Lorenz, Núria Pérez-Zanón, Mattia Righi, Manuel Schlund, Daniel Senftleben, Katja Weigel, and Sabrina Zechlau"Postprint (published version

Secuencias de patrones sinópticos asociados al exceso de mortalidad por calor en el área metropolitana de Barcelona

Ponencia presentada en: VIII Congreso de la Asociación Española de Climatología celebrado en Salamanca entre el 25 y el 28 de septiembre de 2012.[ES]El estudio examina las condiciones sinópticas que explican el exceso de mortalidad por calor en el área metropolitana de Barcelona. Los episodios que se han tenido en cuenta en el estudio se han definido a partir del umbral establecido por el percentil 95 de la mortalidad diaria para los meses del verano (junio, julio y agosto) en la ciudad de Barcelona, asumiendo el lapso transcurrido entre el día en que se registra el máximo de mortalidad y cuando se inicia realmente el episodio de calor. Así, el análisis se basa en la evolución sinóptica entre estos dos momentos, es decir, la secuencia. El estudio se desarrolla a partir de un armazón metodológico sustentado en un análisis multivariable para conseguir una clasificación de las secuencias de los patrones de circulación atmosférica integrando diferentes niveles de la troposfera con la finalidad de detectar la evolución y el comportamiento sinóptico de estos episodios extremos.[EN]The study examines the synoptic conditions that explain the excess of the mortality due to heat in the metropolitan area of Barcelona. The episodes which we have been taken into account in the study were defined from the 95th percentile of daily mortality for the summer months (June, July and August) in Barcelona, assuming the period between the day when it is recorded the highest mortality and when actually begin the episode of heat. Thus, the analysis is based on the synoptic evolution between these two moments, that is to say, the sequence. The study is developed from a methodological framework supported by a multivariate analysis to obtain a classification of the circulation pattern sequences integrating different levels of the atmosphere in order to detect evolution and the synoptic behaviour of these extreme events

Seasonal patterns of pollen sedimentation in Lake Montcortès (Central Pyrenees) and potential applications to high-resolution paleoecology: a 2-year pilot study

14 páginas, 2 tablas, 10 figuras.Lakes with varved sediments are especially well suited for paleoecological study, from annual to even seasonal resolution. The interpretative power of such high-resolution paleoenvironmental reconstructions relies on the availability of modern analogs with the same temporal resolution. We studied seasonal pollen sedimentation in varved Lake Montcorte`s, Central Pyrenees (Spain), as a modern analog for highresolution reconstruction of Late Holocene vegetation and landscape dynamics. Seasonal samples were obtained from sediment traps that were submerged near the maximum water depth for a 2-year period (fall 2013 to fall 2015). Seasonal pollen sedimentation was compared with meteorological variables from a nearby weather station. Bulk pollen sedimentation, dominated by Pinus (pine) and Quercus (oak), followed a clear seasonal pattern that peaked during the spring/summer, coinciding with maximum temperature and precipitation, minimum relative humidity and moderate winds from the SSE. Pollen sedimentation lags (PSL) were observed formost pollen types, as substantial amounts of pollen were found in the traps outside of their respective flowering seasons. Two pollen assemblages were clearly differentiated by their taxonomic composition, corresponding to spring/summer and fall/winter. This pattern is consistent with existing interpretation of the sediment varves, specifically, that varves are formed by two-layer couplets that represent the same seasonality as pollen. We concluded that pollen sedimentation in Lake Montcorte`s exhibits a strong seasonal signal in the quantity of pollen, the taxonomic composition of the pollen assembalges, and relationships between the pollen and meteorological variables. Thus, varved sediments provide a potentially powerful tool for paleoecological reconstruction at seasonal resolution. This method could be used not only to identify paleoenvironmental trends, but also to identify annual layers and therefore date sediments, even in the absence of evident sediment laminations. A satisfactory explanation of PSL will require further studies that examine internal lake dynamics and pollen production/dispersal patterns.This work was funded by the Ministry of Economy and Competitivity (project MONT-500; reference CGL2012-33665; PI: Teresa Vegas-Vilarru´bia).Peer reviewe

Climate Services Toolbox (CSTools) v4.0: from climate forecasts to climate forecast information

Despite the wealth of existing climate forecast data, only a small part is effectively exploited for sectoral applications. A major cause of this is the lack of integrated tools that allow the translation of data into useful and skillful climate information. This barrier is addressed through the development of an R package. Climate Services Toolbox (CSTools) is an easy-to-use toolbox designed and built to assess and improve the quality of climate forecasts for seasonal to multi-annual scales. The package contains process-based, state-of-the-art methods for forecast calibration, bias correction, statistical and stochastic downscaling, optimal forecast combination, and multivariate verification, as well as basic and advanced tools to obtain tailored products. Due to the modular design of the toolbox in individual functions, the users can develop their own post-processing chain of functions, as shown in the use cases presented in this paper, including the analysis of an extreme wind speed event, the generation of seasonal forecasts of snow depth based on the SNOWPACK model, and the post-processing of temperature and precipitation data to be used as input in impact models.This research has been supported by the Horizon 2020 (S2S4E; grant no. 776787), EUCP (grant no. 776613), ERA4CS (grant no. 690462), and the Ministerio de Ciencia e Innovación (grant no. FPI PRE2019-088646).Peer Reviewed"Article signat per 19 autors/es: Núria Pérez-Zanón, Louis-Philippe Caron, Silvia Terzago, Bert Van Schaeybroeck, Llorenç Lledó, Nicolau Manubens, Emmanuel Roulin, M. Carmen Alvarez-Castro, Lauriane Batté , Pierre-Antoine Bretonnière, Susana Corti, Carlos Delgado-Torres, Marta Domínguez, Federico Fabiano, Ignazio Giuntoli, Jost von Hardenberg, Eroteida Sánchez-García, Verónica Torralba, and Deborah Verfaillie"Postprint (published version

CSIndicators: Get tailored climate indicators for applications in your sector

CSIndicators is an R package that gathers generalised methods for the flexible computation of climate-related indicators. Each method represents a specific mathematical approach which is combined with the possibility of selecting a flexible time period to define the indicator. This enables a wide range of possibilities for tailoring indicators to sectorial climate service applications. This package is intended for sub-seasonal, seasonal and decadal climate predictions, but its methods are also applicable to other time scales. Additionally, this package is compatible with the CSTools R package for climate forecast post-processing.This package was developed in the context of H2020 MED-GOLD (776467), S2S4E (776787), VITIGEOSS (869565) projects and Horizon Europe ASPECT project (101081460).Peer ReviewedPostprint (published version

Analysis of extreme rainfall in the Ebre Observatory (Spain)

The relationship between maximum rainfall rates for time intervals between 5 min and 24 h has been studied from almost a century (1905-2003) of rainfall data registered in the Ebre Observatory (Tarragona, Spain). Intensity-duration-frequency (IDF) curves and their master equation for every return period in the location have been obtained, as well as the probable maximum precipitation (PMP) for all the considered durations. In particular, the value of the 1-day PMP has resulted to be 415 mm, very similar to previous estimations of this variable for the same location. Extreme rainfall events recorded in this period have been analyzed and classified according to their temporal scale. Besides the three main classes of cases corresponding to the main meteorological scales, local, mesoscale, and synoptic, a fourth group constituted by complex events with high-intensity rates for a large range of durations has been identified also, indicating the contribution of different scale meteorological processes acting together in the origin of the rainfall. A weighted intensity index taking into account the maximum rainfall rate in representative durations of every meteorological scale has been calculated for every extreme rainfall event in order to reflect their complexity

Analysis of synoptic patterns in relationship with severe rainfall events in the Ebre Observatory (Catalonia)

The study has obtained a classification of the synoptic patterns associated with a selection of extreme rain episodes registered in the Ebre Observatory between 1905 and 2003, showing a return period of not less than 10 years for any duration from 5 min to 24 h. These episodes had been previously classified in four rainfall intensity groups attending to their meteorological time scale. The synoptic patterns related to every group have been obtained applying a multivariable analysis to three atmospheric levels: sea-level pressure, temperature, and geopotential at 500 hPa. Usually, the synoptic patterns associated with intense rain in southern Catalonia are featured by low-pressure systems advecting warm and wet air from the Mediterranean Sea at the low levels of the troposphere. The configuration in the middle levels of the troposphere is dominated by negative anomalies of geopotential, indicating the presence of a low or a cold front, and temperature anomalies, promoting the destabilization of the atmosphere. These configurations promote the occurrence of severe convective events due to the difference of temperature between the low and medium levels of troposphere and the contribution of humidity in the lowest levels of the atmosphere.Peer ReviewedPostprint (author's final draft

Seasonal patterns of pollen sedimentation in Lake Montcortès (Central Pyrenees) and potential applications to high-resolution paleoecology: a two-year pilot study.

Lakes with varved sediments are especially well suited for paleoecological study, from annual to even seasonal resolution. The interpretative power of such high-resolution paleoenvironmental reconstructions relies on the availability of modern analogs with the same temporal resolution. We studied seasonal pollen sedimentation in varved Lake Montcorte`s, Central Pyrenees (Spain), as a modern analog for highresolution reconstruction of Late Holocene vegetation and landscape dynamics. Seasonal samples were obtained from sediment traps that were submerged near the maximum water depth for a 2-year period (fall 2013 to fall 2015). Seasonal pollen sedimentation was compared with meteorological variables from a nearby weather station. Bulk pollen sedimentation, dominated by Pinus (pine) and Quercus (oak), followed a clear seasonal pattern that peaked during the spring/summer, coinciding with maximum temperature and precipitation, minimum relative humidity and moderate winds from the SSE. Pollen sedimentation lags (PSL) were observed for most pollen types, as substantial amounts of pollen were found in the traps outside of their respective flowering seasons. Two pollen assemblages were clearly differentiated by their taxonomic composition, corresponding to spring/summer and fall/winter. This pattern is consistent with existing interpretation of the sediment varves, specifically, that varves are formed by two-layer couplets that represent the same seasonality as pollen. We concluded that pollen sedimentation in Lake Montcorte`s exhibits a strong seasonal signal in the quantity of pollen, the taxonomic composition of the pollen assembalges, and relationships between the pollen and meteorological variables. Thus, varved sediments provide a potentially powerful tool for paleoecological reconstruction at seasonal resolution. This method could be used not only to identify paleoenvironmental trends, but also to identify annual layers and therefore date sediments, even in the absence of evident sediment laminations. A satisfactory explanation of PSL will require further studies that examine internal lake dynamics and pollen production/dispersal patterns