bluuebunny/crossref_metadata_2025 huggingface dataset:
New integrated Date Rescue Portal  - Facilitating DARE projects
Authors: van der Schee Marlies , van der Schrier Gerard , Majoor Martijn , Whan Kirien , Hechler Peer , Poli Paul , Valente Maria Antónia , Brönnimann Stefan , Grab Stefan , Allan Rob , Thorne Peter
Published: July 2024

A new data rescue portal is designed to facilitate and coordinate the rescue of weather and climate data from around the world. It is hosted at https://datarescue.climate.copernicus.eu/. The practical information, data rescue (DARE) projects and metadata inventories originate from initiatives of both the World Meteorological Organization (WMO) and Copernicus Climate Change Service (C3S). All practical information of the  WMO I-DARE portal is merged into this current project and will be replaced by the new portal. IEDRO and ACRE are collaborators for the content of the website.The mission of the portal is as follows:a collaborative framework on sharing information, best practices, know-how, guidance, metadata on data rescue projects and activities worldwide,
provides a single entry point for accessing information on the status of climate data being digitized or in need of recovery and digitization, and
enables collaboration among organizations, development agencies, donors, scientists, NGOs, citizens, to work on the data recovery and digitization of climate heritage which is at risk of loss forever.
One of the main features on the website is the opportunity to highlight your data rescue project. By making your efforts known and publicly available, chances are decreased that the same data is rescued twice by other groups. Additionally, we encourage owners of rescued data to share this in a global repository, so that the valued data will not get lost again. The data portal and project collection also serves as a  starting point for donors to select viable DARE projects which need support. It offers donors the perspective that DARE is done following internationally agreed procedures and that rescued data are shared with the global community rather than the data ending-up in some poorly accessible local file system, which is a multiplier of investment.The C3S Datarescue work package contributes and monitors the efforts on using Artificial Intelligence (AI) and Deep Learning for Optical Character Recognition (OCR) to aid data rescue efforts. The development of a proof of concept for a data rescue image repository is in line with future methods to retrieve valuable meteorological data from scanned paper records with OCR. During the presentation, we will present the latest progress of the C3S DARE work package on the DARE portal, which includes articles on AI efforts to rescue meteorological data.
Effectiveness of the flash flood warning value chain: case study analysis of three recent high-impact events in Australia
Authors: Mooney Carla , Wilke David , Hudson Karen , Heinrich Victoria
Published: July 2024

Flash flooding presents a significant and increasing risk to public safety across many regions of Australia. This type of flooding, which typically occurs over small spatial scales within 6 hours of the onset of rainfall, is often classed as "high-impact, low probability" and is generally difficult to predict. This is because of the uncertainties in forecasting the intensity and spatial-temporal distribution of rainfall and the resulting landscape response. The short timescales associated with flash flooding also mean that there is limited opportunity to warn communities and trigger protective actions during an event.The flash flood warning value chain is complex and involves several inter-related components (from forecasts, observations and warnings through to communication, decisions and response). There are multiple organisations involved, with differing roles and responsibilities, and information flows through the value chain via various channels.In order to identify strategies to improve it is important to understand what is working well in the current service and where there are opportunities for development. This requires significant collaboration with partner agencies to identify pain points with the current approach and needs for a future service.In Australia, the primary responsibility for flash flood warnings lies with the states and territories through emergency services agencies and local councils. The Bureau of Meteorology's role is to provide forecasts, nowcasts and observations for severe weather conditions and to issue warnings for heavy rainfall that may lead to flash flooding.This study will evaluate the effectiveness of the warning value chain through case studies of three recent high-impact flash flood events in Australia: Adelaide, South Australia, November 2023; Hunter Valley, New South Wales, July 2022; Hobart, Tasmania, May 2018. The case study approach will follow the guidelines used in the World Meteorological Organisation (WMO) World Weather Research Programme (WWRP) High Impact Weather Warning Value Chain project. This project uses a multidisciplinary approach combining physical and social science with practitioner perspectives to examine the end-to-end function of the warning service.The outcomes of the analysis will include recommendations to help frame how future services and products can be developed to provide usable and useful intelligence to emergency services agencies and to the broader Australian community during flash flood events.
Mediterranean compound extremes and their link to Mediterranean cyclones
Authors: Portal Alice , Rousseau-Rizzi Raphael , Raveh-Rubin Shira , Catto Jennifer , Givon Yonatan , Martius Olivia
Published: July 2024

Mediterranean weather extremes are often driven by regional low-pressure systems, here under the name of Mediterranean cyclones. In this work we take a Lagrangian (cyclone-centred) and a Eulerian (geographical) perspectives on the association between bi-variate compounds of rain-wind and wave-wind extremes and Mediterranean cyclones. Our aim is to provide new insight on the processes driving the compounding of extreme weather conditions in the extended Mediterranean region. Three main research questions are adressed.(i.) What is the average spatial distribution of compound extremes around cyclone centres?(ii.) How is the regional compound frequency modulated by the presence of cyclones?(iii.) Is the presence of cyclonic air-streams (warm conveyor belts and dry intrusions) and fronts relevant for triggering compound extremes?The results are strongly dependent on the compound type, on the cyclone class and on the season and region of occurrence. We find that in transition seasons compound extremes are far rarer than in the winter season, and that they are mostly associated with a nearby low-pressure centre. The fraction of cyclone-related compounds is weaker during the winter season, even though winter baroclinic cyclones are associated with the highest frequency and spatial extension of compound extremes. Finally, the presence of warm conveyor belts (inflow and ascent), dry intrusion outflow and cold fronts around the cyclone centre is shown to be important for the occurrence of regional compound extremes across all seasons. Warm conveyor belt ascent regions show high occurrence of both types of compound extremes; wave-wind compounds are also favoured in regions of dry intrusion outflow.
Reflections on climate and administrative scales in Western Norway
Authors: Mayer Stephanie , Li Lu , Xie Kun , Sobolowski Stefan
Published: July 2024

Western Norway is one of the regions with the most precipitation in Europe. Average amounts are about 3500 mm per year around and in the mountains near the coast, with up to 5000 mm in peak years. The wet climate is mainly caused by the North Atlantic Current, which also gives this region a milder winter than other parts of Norway, with rain being more frequent than snow. 

Enhancement of rainfall (intensity, frequency, duration) and attendant flooding is the main physical climate risk for Western Norway.  As such, we focus on changes in frequency and magnitude of daily and sub-daily precipitation and discuss the added value resulting from convection permitting regional climate models at basin scale. 

Concomitantly, the Norwegian Centre for Climate Services and the Impetus4Change project aim to overcome the barrier of providing (only) gridded data from climate simulations on a data portal. Thus, we focus on the development of accessible, user-friendly climate information relevant for the local planning authorities (i.e., municipalities). In alignment with Norway’s Planning and Building Act, we aim to promote the integration of tailored climate data into municipal planning strategies. These inform the so-called “master plan” of the municipality which is the most important management document of the municipal council. Tailoring climate information in this way, rather than exclusively through the conventional methods of climate report writing and data dissemination via web portal, ensures that climate information are fit for purpose (i.e., municipal planning) and will enhance the uptake, usefulness and impact of climate services. 
Update on the Use of Uncrewed Aircraft Systems for Operational Meteorology and Atmospheric Research
Authors: Bärfuss Konrad , Gallia Mariachiara
Published: July 2024

Currently, the WMO UAS-DC, which “aims at demonstrating the potential capability of UAS to play a role as an operational component of the WMO Integrated Global Observing System (WIGOS) under the Global Basic Observing Network (GBON).” [WMO, 2024] is running since March 2024, with Special Observing Periods in April, August, and September 2024.Around 50 operators of uncrewed aircraft systems, including private entities, NHMS, and research institutions, plan to contribute atmospheric measurements worldwide. Beyond the operator group, the data user group is expected to utilize the obtained data, assess their quality, and potentially guide observational and simulation experiments to explore their impact, distinct from traditional sources like radiosondes or the TAMDAR/AMDAR system. Initial results are anticipated in 2024, providing insights into system capabilities, deployed types, robustness, and operational modes.The presentation aims to provide a comprehensive overview of global activities and common challenges faced. As most of the uncrewed measurement systems are deployed beyond visual line of sight, specific rules for granting permissions have to be applied. In addition to regulatory and safety concerns, hurdles related to adverse weather conditions such as high wind speed, precipitation, and in-flight icing are significant and will be discussed from the point of view of the operations by the Institute of Flight Guidance, Technische Universität Braunschweig, Germany. Considering these aspects when projecting the future use of uncrewed aircraft systems in operational meteorology is crucial. A detailed examination of observational data and operation records will allow for an assessment of the progress demonstrated during the WMO UAS-DC.
Impact of Early Winter-Spring Transition on the Development Dynamics of theMoth Family Tortricidae and Host Plants
Authors: Marcic Milena , Lalic Branislava , Firanj Sremac Ana , Koci Ivan
Published: July 2024

Global warming is one of the most significant characteristics of climate change. Serbia is no exception; it was noted that the daily mean air temperature and the number of days with extreme weather conditions have increased. The tropical days that used to be common for the summer months recently have been registered in May and even April.Extreme weather events can disrupt our usual perception of the time of occurrence of the development stages of pests and growth stages of plants. Since air temperature is the main trigger of plant and harmful organism development, a warm period occurrence earlier than usual in the spring could cause the earlier emergence of the pest and the earlier start of plant growing season.Over the past fourteen years, meteorological conditions have been measured in the plant canopies as part of the Forecasting and Warning Service for Plant Protection of Serbia (PIS) monitoring system. Extremely high winter temperatures and early winter-spring transition compared to the region's climatology are recorded, affecting plant and pest phenology dynamics. This research is focused on effects registered in the moth family Tortricidae (Lepidoptera) and their host plants.The occurrence of different stages for the codling moth (Cydia pomonella) and apples, the oriental fruit moth (Grapholita molesta) and peach, the plum fruit moth (Grapholita funebrana) and plum, and the grape berry moth (Lobesia botrana) and grapevine, were analyzed and their association with air temperature and season transition indices. The data used in the study are gathered through the PIS monitoring network. Biological data series are collected on production plantations where protection measures were regularly applied. Biofix data, as well as timing and population of adults, are gathered using pheromone traps. Eggs and larvae presence, as well as the growth stages of host plants, result from visual inspections in the orchards and vineyards. Depending on the species, 20-40 locations were analyzed annually for each pest for 2012-2024.Our research aims to explore the impact of extreme winter temperatures and winter-spring transitions on the development of pests and host plants. Monitoring and understanding these effects is crucial for accurately forecasting and effectively managing adverse impacts on agriculture.
Atmospheric environmets of convectively generated wind gusts in Southern Brazil
Authors: Ferreira Vanessa , de Lima Nascimento Ernani de Lima , de Oliveira dos Santos Letícia
Published: July 2024

This study investigates convective wind gusts measured by National Meteorological Institute (INMET, in Portuguese) operational automated surface weather stations network in southern Brazil from 2005 to 2015. Only events unequivocally associated with deep convective storms were selected, as evaluated with a set of criteria that include the employment of geostationary satellite data. Wind gusts exceeding 25 ms -1 are categorized as severe, while non-severe gusts with moderate intensity range from 15 ms -1 to 24.9 ms -1, and weaker gusts from 10 ms -1 to 14.9 ms -1.Convective parameters computed from the Fifth Generation of the European Centre for Medium-Range Weather Forecasts Reanalysis (ERA5) are used to investigate the atmospheric conditions conducive to severe wind gusts. Emphasis is placed on assessing the ability of convective parameters to discriminate between severe and sub-severe wind gust environments. The results indicate that the mean wind computed from the surface to the 6 km layer was the only parameter that showed some discriminatory ability. Overall, convective parameters alone are unable to distinguish environments conducive to the formation of storms capable of generating intense winds from those generating weak wind gusts. This result aligns with ingredient-based analysis, as individual parameters alone do not encompass all the necessary ingredients required for the development of these storms.Therefore, we evaluate the combined product of ERA5-based convective available potential energy (CAPE) and bulk wind difference in the 0-6 km layer (BWD). The results indicate that as the gust intensity increase, the high CAPE high shear space gradually becomes more preferable. In other words, there is a tendency for more severe storms to cluster in the sector of the diagram where both CAPE and BWD values are moderate to high. 
Wind climatology of surface wind patterns in the coastal region of Croatia
Authors: Kožul Ena , Odak Plenković Iris
Published: July 2024

Understanding wind climatology and examining wind speed and direction patterns using available measurements, is vital across various sectors, including urban planning, transportation, environmental monitoring, and safety management. Surface air pressure distribution, categorized into distinct weather types, significantly influences surface air flow. This airflow can bring benefits like a refreshing sea breeze on a hot summer evening. However, wind can also pose significant challenges during severe conditions, particularly in the coastal region of Croatia. Therefore, accurately classifying wind characteristics in this region is highly beneficial for effective management and preparedness.In this work, we used surface data observations from main and climatological meteorological stations over a ten-year period (2013–2022) to classify both strong wind events and characterize their seasonality, and also coastal circulation. Intense synoptic systems, such as warm and cold fronts associated with low-pressure systems, as well as the passage of these systems, contribute to episodes of strong winds in the region. Two prevalent local winds, bora and jugo, though distinct in nature and originating from different synoptic systems, can both pose challenges to transportation, maritime activities, and even threats to both people and properties. Those winds are dominant in the colder part of the year. The bora wind occurs during anticyclonic weather types in cases of sudden outbreaks of cold air from north or northeastern part of the Europe, and jugo prevails when there is cyclonic weather type, more specifically it is formed on the front side of the cylone above Medditerranean.The eastern coast of the Adriatic Sea is characterized by numerous islands and complex topography along the coastline. In warmer part of the year when the synoptic conditions are not intense, an etesian wind known as the maestro prevails in this area. This consistent wind pattern is crucial for temperature regulation during high daytime temperatures and plays a significant role in maritime navigation. Coastal circulation forms under similar synoptic situations, influencing the diffusion of aerosols, temperature regulation, and convection triggering. Finally, the complex indentation of the Croatian coastline, with many islands, necessitates examination of island circulation and its potential interference with the main coastal circulation. 
Comparing Reanalysis and Observational Data for GHG Emissions and Air Pollutants in the EMME Region
Authors: Christodoulou Konstantinos
Published: July 2024

The critical challenge of climate change in the Eastern Mediterranean and Middle East (EMME) region, especially on the island of Cyprus, is closely linked to the emissions of greenhouse gases and the dispersion of air pollutants. This study utilizes reanalysis gridded data from multiple open data platforms, including the Copernicus Atmospheric Monitoring Service (CAMS), providing unprecedented access to large-scale datasets specifically focused on emissions and pollutants within this region. By analyzing different gridded datasets, the research aims to develop a detailed understanding of the spatial and temporal patterns of emissions, dispersion processes, and their interplay with atmospheric conditions across various sectors.
The approach involves data aggregation from diverse open sources, employing advanced analytics to decode complex spatial and temporal variations, and comparative assessments to identify discrepancies and trends between reanalysis data and actual observations. This study will assess how reanalysis climatic factors contribute to the variability in emissions and pollutant levels, thereby evaluating the environmental impacts specific to various sectors and the effectiveness of current mitigation strategies throughout the EMME region, with a particular emphasis on the situation in Cyprus.
Although preliminary results are yet to be generated, the expected findings aim to offer significant insights into the dynamics of emissions and pollution dispersion within this region. This investigation not only highlights the critical role of open and reanalysis data in environmental research but  aims to make a substantial impact on regional discussions about sustainable practices by offering practical, data-driven insights. Furthermore, this study will explore how these findings can inform and enhance regional climate policy and action plans. It will particularly demonstrate how reanalysis data can be pivotal in understanding and tackling the complex issues of climate change in the EMME region, making it an essential contribution to the field of spatial climatology and regional environmental policy-making.
 
Do you have to be great at TikTok to reach kids?
Authors: Svehagen Mai-Linn Finstad , Vågane Julie Solsvik , Sivle Anders Doksæter , Gislefoss Kristian
Published: July 2024

In 2023 a small team at MET Norway - the Sandbox - started working on ideas of communicating more directly with kids about weather forecasts and warnings in a changing climate. We want kids growing up, knowing where to find weather forecasts and information about the weather and climate. And that they know and trust the source. With AI and the vast amount of information and weather services there are, it is essential for us that they know us as a reliable source the day they need us.At MET Norway we have been developing weather services for a broad audience since 2007 (Yr). We learned that digital services should be developed according to user needs and not our needs. All users benefit from good communication. Plain language and simplification is a good start. Therefore we have started looking at how we communicate with kids.Kids in Norway learn some basics about weather and climate in school. We have conducted four surveys since 2020, mapping how kids and young people use weather forecasts. We also have a very popular online encyclopedia in Norway that schools use, but the majority does not know that MET Norway is the source of the content related to weather and climate. The surveys and our experience show us that we need to be more visible and active in how we communicate.MET Norway has been successful in communicating weather forecasts in Social Media. An interdisciplinary Social Media team, led by a communications expert and a meteorologist, makes content in different formats and answers questions from the public. The overall reach is good, except in the youngest user groups. But do you have to be the next big hit on TikTok to do that? We don't think so. Kids need help to learn the basics. How to get dressed for everyday activities and what they need to know to be happy and safe doing them. They would also like to know what they can do for the climate and the environment. They need an honest, useful and reliable source of information. Our goal is to give them that.In 2023 we had meetings with organizations and companies that communicate great with kids, to get inspiration and advice. In 2024 we started working on our language and got financial support to work on a design profile. We have made two ready made assignments for teachers to use. And together with an amusement park we are launching a digital board game that will be used in communicating weather, climate change and clean energy.Addressing this theme at the EMS, we hope to inspire others to work on communicating better with kids and young people.
Study of the physical mechanisms during sea breeze events in the Mallorca island through observations and simulations
Authors: Jimenez Maria A. , Grau Antoni , Marí Laura , Cuadros Lluis , Serra Alex , Maimó-Far Aina
Published: July 2024

The physical mechanisms that take place under sea-breeze (SB) conditions in the island of Mallorca (western Mediterranean Sea) are analysed through the inspection of data from automatic weather stations (AWS) from the Spanish Meteorological Agency (AEMET) during the period 2009–2022. Hourly satellite-derived land-surface and sea-surface temperatures (LST and SST, respectively) are used to compute the surface temperature difference (LST–SST) in the three main basins. Besides, a method (Grau et al, 2020) is taken to select the SB events in the three main basins using data from AWS during the warm months of the year (from April to September). Results from the statistical analysis of the selected SB events show that the ranges of the temperature difference change in the three main basins pointing to the presence of other physical mechanisms in the setup of the sea breeze and the propagation of the sea-breeze front. It is found that there are differences in the SB features of the three basins (maximum wind speed, initiation and duration of the SB). Besides, in general SB conditions are not simultaneously met in the three basins, but when they do they can interact strongly.To check if models are able to capture these observed physical mechanisms, data from the Copernicus regional reanalysis for Europe (CERRA) are taken. The features of the selected SB events obtained from the data analysis are compared to those obtained by the model at 5km spatial resolution. It is found that the thermal gradient is well captured by the model but a misrepresentation of the topography and other surface features might be the responsible of the differences between model and observations.The representation by numerical models of some selected SB events are further analysed through mesoscale simulations made with the MesoNH model. Three nested domains are taken (horizontal resolutions of 5km, 1km and 250m) and the inner one is centered in the studied basin. The vertical resolution is 3m at the surface and stretched above. For a particular basin, the SB interacts with the already present locally-generated winds within the same basin but also with the SB generated in the other basins. Simulations clearly show that the SB is a cold and humid advection that interacts with the surface energy balance terms once it propagates inland.
The crucial representation of deep convection for the cyclogenesis of medicane Ianos
Authors: Pantillon Florian , Davolio Silvio , Avolio Elenio , Calvo-Sancho Carlos , Carrió Diego S , Dafis Stavros , Flaounas Emmanouil , Gentile Emanuele Silvio , Gonzalez-Aleman Juan Jesus , Gray Suzanne , Miglietta Mario Marcello , Patlakas Platon , Pytharoulis Ioannis , Ricard Didier , Ricchi Antonio , Sanchez Claudio
Published: July 2024

The paper presents a model intercomparison study to improve the prediction and understanding of Mediterranean cyclone dynamics. It is based on a collective effort with five mesoscale models to look for a robust response among ten numerical frameworks used in the community involved in the networking activity of the EU COST Action "MedCyclones". The obtained multi-model, multi-physics ensemble is applied to the high-impact medicane Ianos of September 2020 with focus on the cyclogenesis phase, which was poorly forecast by numerical weather prediction systems. Models systematically perform better when initialised from operational IFS analysis data compared to the widely used ERA5 reanalysis. Reducing horizontal grid spacing from 10 km with parameterised convection to convection-permitting 2 km further improves the cyclone track and intensity. This highlights the critical role of deep convection during the early development stage. Higher resolution enhances convective activity, which improves the phasing of the cyclone with an upper-level jet and its subsequent intensification and evolution. This upscale impact of convection matches a conceptual model of upscale error growth in the midlatitudes, while it emphasises the crucial interplay between convective and baroclinic processes during medicane cyclogenesis. The ten numerical frameworks show robust agreement but also reveal model specifics that should be taken into consideration, such as the need for a parameterization of deep convection even at 2 km horizontal grid spacing in some models. While they require generalisation to other cases of Mediterranean cyclones, the results provide guidance for the next generation of global convection-permitting models in weather and climate.
Enhancing High Wind Speed Event Prediction through Adaptive Analog Ensemble Sizing
Authors: Lozuk Jakov , Odak Plenković Iris , Vujec Ivan
Published: July 2024

The Croatian Meteorological and Hydrological Service (DHMZ) has a long experience in post-processing wind speed and wind gust variables. One of the most used methods at DHMZ is the analog method. Although notable improvements in wind speed forecasts have been observed, one of the disadvantages of the analog method is its accuracy in forecasting high wind speed episodes, especially when using an analog ensemble for deterministic post-processing (HRAN). Since onshore parts of Croatia regularly experience violent winds several times a year, leading to disruptions in electricity production and traffic, accurate high wind speed forecasts hold significant importance.  This study investigates the impact of reducing the analog ensemble size on HRAN accuracy. Analysing wind speed forecasts from onshore locations in Croatia, we compare raw model output and HRAN with predictor weight optimisation. In the analysis, we use ALADIN-HR NWP, tuned for wind across Croatian territory, providing us with forecasts 72 hours ahead. Utilising measures for continuous forecast verification, the overall forecast quality is inspected, while the categorical approach is used for examining forecast performances for more extreme events. Generally, the highest enhancements are achieved with an analog ensemble size of 15 members. Since high winds are rare, compared to low and moderate winds, employing larger ensembles often results in overall error reduction. However, our study shows how fewer than 15 ensemble members can provide more favourable results for the highest wind categories, causing less pronounced underestimations. Thus, varying ensemble size might be an optimal way to address these issues. In the ongoing work, besides wind speed forecasts, the analog method is also used to improve visibility forecasts, focusing on low-visibility events often caused by fog.
Nitrogen Dioxide (NO2) and Particle Measurements within Cities using a Multi-Rotor Uncrewed Aerial System
Authors: zum Berge Kjell , Mauz Moritz , Geske Franziska , Bange Jens , Platis Andreas
Published: July 2024

Recent urban development trends have increased focus on air quality, drawing significant attention from the public, media, and policymakers. Key pollutants such as particulate matter and nitrogen dioxide (NO2) - primarily emitted by vehicles, energy production, and heating - pose substantial health risks. To address this, the EU has implemented several strategies, including driving bans, speed limits, and green space enhancements. Despite these efforts, the effectiveness of pollution assessments using conventional monitoring stations, which are sparse and limited, has been a topic of extensive debate in public and scientific forums.Moreover, establishing an extensive sensor network throughout a city presents financial and logistical challenges, including high costs, intensive maintenance, and competition for public space. To circumvent these issues and bolster public support for pollution control, an innovative approach involving small, affordable unmanned aircraft systems (UAS) has been developed. This partnership, backed by the Federal Ministry for Digital and Transport and involving select municipalities, focuses particularly on enhancing NO2 measurement precision. The system utilizes cutting-edge, high-precision NO2 sensors mounted on drones to collect accurate and flexible data on nitrogen oxides and particulate matter. This methodology, supported by recent guidelines on pollutant dispersion using UAS, enables targeted measurement campaigns both before and after the implementation of pollution reduction measures. By deploying these drones, comprehensive datasets covering particulate and gas concentrations alongside meteorological conditions can be obtained across various locations. The data are then analyzed to evaluate the efficacy of the implemented pollution control measures, thus providing a novel, high-resolution approach in NO2 measurements on a vertical scale to urban air quality management.
Improving Satellite Cloud Thickness Characterization by means of Ceilometer Data
Authors: D'Amico Filippo , Perona Daniele , Ronzio Dario , Collino Elena , Bonanno Riccardo
Published: July 2024

As PV technology evolves, more sophisticated methods of solar irradiance forecasting and ex-post estimation are needed for PV power forecasting and monitoring purposes, especially regarding the different components ( Direct, Global and Diffuse) and their spectral distribution. To achieve an accurate prediction across the spectrum for each component, radiative transfer models (RTMs) are often used; however, they are based on a vertical characterization of the atmosphere, and particularly of cloud thickness, which  traditionally is retrieved as a fixed thickness values for each different cloud type (under the assumption that same-type clouds have the same thickness) or from NWP models.In this field, a relatively new and quite promising technology that helps in better characterizing the clouds is the ceilometer, a ground-based lidar instrument designed for vertical profiling offering high-resolution assessments of cloud properties. RSE S.p.A. installed one such instrument (Vaisala CL61) in Milan (Italy) in June 2023. The goal of this early-stage study is to exploit the ceilometer’s cloud base measurements and satellite’s cloud top height estimations to train a machine learning model to derive the information on the vertical thickness. We aim to use  the same model to obtain experiment-based estimates of cloud thickness over the entire Italian domain, to be used in RSE’s choice RTM (libRadtran).The starting dataset to train the model consists of:Backscatter and depolarization measurements from the Milan-based ceilometer, from which it is straightforward to obtain the cloud base height. The data has a 1-minute time frequency and a 5m vertical resolution over a 10-month period.
Meteosat Second Generation satellite data, from which cloud position, cloud type and cloud top height have been inferred. The data has a 15-minute time frequency and a 4 km spatial resolution (parallax and data acquisition time have been accounted for).
From the dataset, it is straightforward to calculate the thickness of single-layer clouds as the difference between the cloud top (satellite) and cloud base (ceilometer). The cloud thickness has therefore been used as predictand in a random forest model (RF), using the cloud type and the cloud top height as predictors. Other meteorological variables can also be added as predictors.The method’s accuracy has been tested indirectly by comparing the irradiance components calculated using libRadtran fed with the RF derived cloud thickness with respect to the experimental ones, registered in different Italian sites.
A campaign re-analysis for ‘Swabian MOSES 2023’: how do high-resolution observations change the analysis of a convective-scale data assimilation system?
Authors: Thomas Julia , Geppert Gernot , Reich Hendrik , Steinert Thorsten , Anlauf Harald , Keller Jan , Knippertz Peter , Oertel Annika
Published: July 2024

Natural hazards associated with mesoscale processes such as summertime convective events pose a considerable threat to people and property. Yet, forecasting such events remains a challenge, even for the latest generation of high-resolution, convective-scale numerical weather prediction models. Their forecast quality in such cases will likely benefit from improved initial conditions in form of an improved data assimilation analysis. Thus, the assimilation of high-resolution measurements of the lower troposphere has a high potential to enhance the predictability of convective conditions. For example, recent studies by the German Weather Service (DWD) in Aachen and Lindenberg suggest a positive influence of additional Doppler wind lidars (DWLs) on the analysis. However, a thorough investigation of the impact of additional ground-based observations in complex terrain is still lacking.The ‘Swabian MOSES’ campaign took place from June to August 2023 in the German Black Forest mountain range and deployed a spatially distributed network of instruments to observe the dynamic and thermodynamic characteristics of the lower troposphere. Among them was a network of 12 DWLs, which together have never been used for data assimilation experiments before. Here, we present a 3-months campaign re-analysis dataset that uses a wealth of remote sensing and in-situ campaign observations. These data are added to the regional forecasting system of the DWD, which employs the non-hydrostatic model ICON at 2 km resolution (ICON-D2) and the Kilometer Scale Ensemble Data Assimilation system (KENDA) with 40 ensemble members that uses a Local Ensemble Transform Kalman Filter. We assimilate additional vertical profiles of the horizontal wind retrieved from the DWLs, targeted radiosoundings released from two sites during intensive observation periods, ground based zenith path-delay observations from a (not yet operational) German-wide network of Global Navigation Satellite Systems receivers, and 2-meter temperature and relative humidity as well as surface pressure observations.In this contribution, we present our experimental setup, address challenges associated with the assimilation of non-operational observations, and demonstrate how different observations influence the campaign re-analysis. Moreover, we compare the campaign re-analysis with a quasi-operational reference re-analysis without additional observations. Our main focus is on the representation of convective summertime conditions.
International Development Projects of the Finnish Meteorological Insitute 
Authors: Eerikäinen Matti
Published: July 2024

The expert services of the Finnish Meteorological Institute (FMI) has been working over fifty years internationally in improving of the services provided by the different national hydro-meteorological services (NHMS’s) worldwide. The cornerstones of the cooperation with different institutes have been formed around improved disaster risk reduction and adaptation to climate change. So far, the assistance and transfer of know-how has reached more than 100 countries worldwide, mainly concentrating on the developing countries. The main objective of the projects has been to improve the quality, dissemination and effectiveness of the hydro-meteorological forecasts and warning services for the societies first to decrease number of fatalities related to natural disasters and to decrease the economic losses related to the same events.Currently FMI is working in over 20 countries with over 40 on-going projects. These projects have a versatile range of activities related to development of the different sectors in the service production value chain, from observations to end-user forecasts and early warnings, in our sister institutes in emerging countries. Today, as the number of funding sources and mechanisms is constantly increasing in the meteorological field and on the other hand increasing number of developed NHMS are engaged in similar projects in the emerging countries, it has become more vital than ever to share the best practices and coordinate the project activities among the implementing institutes. An overview on the current international development activities of FMI in the emerging countries will be presented and best practices and lessons learned will be shared in the 2024 annual meeting of the European Meteorological Society.
Atmospheric blocking events over Southeast Pacific and Southwest Atlantic oceans in CMIP6 present-day climate
Authors: Ferreira Vanessa , Maroneze Rafael , Toledo Bonfim Osmar , Mortarini Luca
Published: July 2024

Episodes of atmospheric blocking over the Southeastern Pacific and Southweastern Atlantic oceans significantly affect the weather over South America. These blocking events have been associated with heatwaves, droughts, and abnormally wet periods. Given the significant impacts that atmospheric blockings can have on regional climate, it is important to investigate their simulation in general circulation models (GCMs) and document any inherent biases within these models. If models are unable to accurately capture blocking under present-day conditions, it undermines the confidence in their future projections of blocking frequency.However, few studies have examined the representation of Southern Hemisphere blockings in GCMs, especially for the Southeastern Pacific and Southweastern Atlantic regions. Therefore, in this study, we investigate the representation of blocking events in a set of 13 GCMs from the Coupled Model Intercomparison Project Phase 6 (CMIP6) within the domain of the SE Pacific, with boundaries from latitudes 40°S to 65°S and longitudes from 140°W to 82.5°W, and the SW Atlantic, with boundaries from latitudes 40°S to 65°S and longitudes 80°W to 10°W. These areas are of primary interest due to their proximity to the South American continent.Historical runs are employed to analyze blocking conditions in the recent-past climate, focusing on the period from 1985 to 2014. Geopotential height at 500 hPa (Z500) data from the Fifth Generation of the European Centre for Medium-Range Weather Forecasts Reanalysis (ERA5) is utilized to represent the observed state of the atmosphere within the specified domain covering the Southeastern Pacific and Southern Atlantic Oceans.Overall, the analyzed GCMs generally underestimate blocking events in the Pacific sector, although the MPI-ESM1-2-HR and MPI-ESM1-2-LR models closely reproduce observed numbers, with around -10% and -9% underestimation, respectively. For the Atlantic sector, the performance of the CMIP6 models is more varied, and the models seem to have more difficulty in capturing the observed blocking events, with differences exceeding +/-25% compared to ERA5. Nevertheless, most CMIP6 models accurately capture the seasonal distribution of blocking events, with the highest occurrence in winter and the lowest in summer. Additionally, they reproduce the center position, overall area, and Z500 anomalies of the blockings.This research results from the R&D Project from ENGIE Brasil Energia and Companhia Energética Estreito (R&D-00403-0054/2022), and regulated by the Brazilian National Electric Energy Agency (ANEEL). 
Using machine learning to enhance visibility predictions at Zurich Airport
Authors: Wehrli Kathrin , Attinger Roman , Barras Hélène , Landmann Johannes Marian , Aznar-Siguan Gabriela , Exterde Szilvia , Irrgang Melanie , Jordi Thomas , Reiniger Thomas , Stocker Claudia
Published: July 2024

Airport operations, including runway capacity, delays, and aircraft handling, are tightly coupled to weather. Taking preparatory actions for different weather conditions such as changing wind regimes, visibility reductions, and thunderstorms, is a central part of air traffic management. This meteorological predictions that enhance situational awareness and increase plannability.Within the MeteoSwiss AVIA26 project, new aviation weather products are developed to forecast thunderstorms [1], wind, and visibility conditions using a machine learning (ML) approach. They provide predictions with high timeliness, short update cycles, spatial representativeness, and information on occurrence probability. Insights into how the predictions are visualized, disseminated and communicated to stakeholders in order to support decision making are given by Landmann et al. [2].In this contribution, we will focus on the development of an ML-based time series model for predicting visibility at Zurich Airport. We employ the Temporal Fusion Transformer (TFT) model [3], which is an interpretable, multi-horizon, attention-based transformer model for time series. Probabilistic visibility predictions are generated at a 10-minute resolution for the first three hours, and an hourly resolution thereafter up to a lead time of 33 hours. The predictors include visibility measurements, other meteorological station measurements, remote sensing data from satellite, and numerical weather model output. Thanks to the near real-time measurements at and near the airport, predictions can be updated every 10 minutes to reflect the ongoing meteorological tendencies. Both vertical and horizontal visibility time series are predicted simultaneously, resulting in consistent information on visibility regimes at the airport.We investigate the importance of different predictors and optimize the ML model architecture, considering also tree-based models to test the validity of the TFT model for the use case. The performance of the ML-based prediction is compared against the current deterministic forecast, which is generated from post-processed numerical weather prediction and has an hourly granularity. We find a better performance of the ML-based prediction, particularly for relevant visibility thresholds for aviation. Furthermore, the faster update frequency and probabilistic character make it more helpful for planning and decision making in air traffic management. [1] abstract Attinger et al., 2024, submitted to EMS 2024[2] abstract Landmann et al., 2024, submitted to EMS 2024.[3] Lim et al., 2021, https://doi.org/10.1016/j.ijforecast.2021.03.012
AEMET-γSREPS: The Spanish Convection-permitting LAM-EPS on AEMET forecasting offices
Authors: Callado-Pallarès Alfons , Gómez-Navarro Juan José , Gil-Oliva David
Published: July 2024

AEMET-γSREPS is a 2.5km multi-NWP models and multi-boundaries LAM-EPS system operating up to 72 hours since 2016 over Iberian Peninsula, Canary Islands and Antarctica Peninsula which is quite extensively used by AEMET forecasting offices. The main γSREPS goal is to improve operationally issued forecasts and warmings with a consistent measure of their predictability.The γSREPS 20 members come up crossing four regional mesoscale non-hydrostatic convection-permitting NWP models: HARMONIE-AROME (ACCORD-HIRLAM), ALARO (ACCORD-ALADIN), WRF-ARW (NCAR-NOAA) and NMMB (NCEP-NOAA); with five Global NWP models’ boundary conditions: ECMWF-IFS, NCEP-GFS, MétéoFrance-ARPÈGE, JMA-GSM (Japanese) and CMC-GEM (Canadian). Multi-model and multi-boundary approaches have been selected to take into account the NWP model and boundary condition uncertainties respectively. The combination of both prove to hold better skill-spread relationship than other EPS techniques based on uni-NWP models, especially for precipitation and/or convective High Impact Weather (HIW) events.γSREPS has a big number of spatial and point products available for forecasting offices through an integrated visualisation framework called PANEL. Interestingly, the latter integrates them with other forecasting systems in AEMET such as deterministic HARMONE-AROME and ECMWF IFS and also its ensemble IFS-ENS, allowing forecasters to carry out a “poor man ensemble” conceptual prediction integration in order to issue the best possible predictions and warnings. Static spatial plots comprise mean, maximum and minimum fields, quartiles, probabilities, member “spaghettis” and EFI/SOT (Extreme Forecast Index). Precipitation “spaghetti” product depicting every member’s contour precipitation in a number of distinct thresholds, are very appreciated in forecasting offices because it allows them to evaluate spatial uncertainty and look for possible extreme events represented only by a few members. Moreover, the new dynamic visualisation based on ADAGUC facilitates zoom up to a very local region for detailed forecasts. For point-based products, a new generation of meteograms (gSREPSgrams) which includes the most extreme single member are produced along the probabilistic vertical-profile product, which shows the most unstable member. Both products try to highlight possible extreme events.The planned foreseeable evolution of AEMET-γSREPS system is to increase the number of members, incorporating more boundary conditions such as the ones from Global ICON, and including more mesoscale NWP models like ICON-LAM and GEM-LAM.