bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the WRF model’s ability to predict extreme temperatures : a record-breaking high temperatures case in the Basque Country
Authors: Arrillaga Jon Ander , R. Gelpi Ivan , Diaz de Arcaya Aurelio , Castaño Antonio , Gaztelumendi Santiago
Published: July 2023

The summer of 2022 in the Basque Country was characterized by extremely dry and hot conditions. In a major part of the region, precipitation levels were 50% below average, and the mean temperature was 2.4 ºC higher than the 1981-2010 climatology. This made it the warmest summer on record, second only to 2003. In the midst of this arid and sweltering season, a historic persistent and high temperatures event occurred between July 13th and 18th. During the episode, maximum temperatures exceeded 40 ºC in some areas for several consecutive days, with the highest recorded temperature reaching 43.6 ºC. Minimum temperatures were also persistently high, with some stations not dropping below 20 or even 25 ºC during the warmest days.
Given the extreme and challenging context in terms of surface heating and evapotranspiration, we assessed the ability of the WRF model with a operational forecasting configuration to reproduce the observed atmospheric conditions during the estudied case. Although wind patterns and hourly temperature evolution where generally well-reproduced, maximum temperatures were slightly underestimated and minimum temperatures were greatly overestimated in some areas. Specifically, the WRF configuration did not accurately capture the local weakening of wind at night and the subsequent formation of surface-based thermal inversions on days when offshore southerly winds prevailed.
In this work we present different aspects related with the fine-tune temperature prediction during this significant heatwave episode. We present results from different sensitivity experiments on the operational configuration. We tested various dynamics options, finer land-use databases, and physical parameterizations. We also include some comparison results with other forecast systems available in Euskalmet as other mesoescale models or statistical prediction systems.
Integration of four X-band radars into the existing C-band network: focus on the correction for specific attenuation
Authors: Antonoglou Nikolaos , Blahak Ulrich , Werner Manuel , Helmert Kathleen
Published: July 2023

The combination of C-band and X-band radar networks has become increasingly popular in recent years, as it offers significant benefits for a range of applications. C-band and X-band radars use different frequencies, with the prior operating at around 5.6 GHz and the latter operating at around 9.3 GHz, leading to wavelengths of 5.3 and 3.2 cm, respectively. This means that the two types of radar have different characteristics and are suited to different applications.
When combined, the two radar types complement each other's strengths and weaknesses. C-band radar can cover a larger area and provide a general overview of the environment being monitored, while X-band radar can provide detailed information about specific targets within that area. By combining these two types of radar, it is possible to obtain a more accurate and complete picture of the environment being monitored, with both high resolution and extended range. On the other hand, the combination of different-frequency radars in one processing chain brings several challenges. The backscattering profiles are different in each system, resulting in distinct observation patterns. Moreover, each frequency is subject to different attenuation rates, according to which, the appropriate corrections need to be applied.
The German Weather Service (Deutscher Wetterdienst – DWD) operates a network of 17 C-band radars and in the following months will start to install four additional X-band systems in the urban areas of Karlsruhe, Nürnberg, Halle, and Bremen. The goal is to extend the coverage of the network and improve the early detection of thunderstorms that could potentially cause flash floods. As an initial step, we aim at quantifying the specific attenuation for all types of precipitation and the two frequencies. This process is fundamental for the realistic correction of the observations, particularly for higher-frequency signals that are more heavily impacted by attenuation.
Investigating process levels of the German Climate Forecast System
Authors: Isensee Katharina , Wandel Jan , Fröhlich Kristina , Brune Sebastian , Sylla Adama , Baehr Johanna , Früh Barbara
Published: July 2023

Usually, climate forecast systems are assessed in deterministic and probabilistic quality metrics for error and correlation on reference data sets. Here we apply two diagnostic tools on the seasonal forecast system to learn more about possible mechanisms, which gover the respective forecast skill.
By using the delta maps tool (Falasca et al., 2019) we are looking especially for ENSO-teleconnected regions of the model system during boreal spring and boreal winter in comparison with ERA5. The tool generates clusters of multiple grid points, whose time series correlate and therefore are characterised with similar physical behavior. Delta maps was originally designed for data from climate projections but has been adapted to seasonal forecast output. We aim for a better understanding of the pronounced spring predictability barrier in GCFS2.1 and how this evolves in its successor GCFS2.2.
The Warm Conveyor Belt metric (Quinting and Grams, 2022) is designed up to study the role of physical processes and their influence on the large-scale circulation in NWP and climate models. The metric has been successfully applied to sub-seasonal forecast models (Wandel et al. 2021) where a general underestimation of WCB frequencies and a potential link to circulation biases is found. We here apply the metric to the GCFS2.1 hindcasts (1993-2016) in the boreal winter season. Due to the strong link between air masses from WCBs and large-scale weather regimes, the analysis will help to understand general model behavior  and error development which will ultimately help to increase the prediction skill of the weather regimes in the forecasting system.
Falasca, F., Bracco, A., Nenes, A., & Fountalis, I. . Dimensionality reduction and network inference for climate data using δ‐MAPS: Application to the CESM Large Ensemble sea surface temperature. Journal of Advances in Modeling Earth Systems, 11, 1479– 1515. https://doi.org/10.1029/2019MS001654 (2019).
Quinting, J. F. and Grams, C. M.: EuLerian Identification of ascending AirStreams (ELIAS 2.0) in numerical weather prediction and climate models – Part 1: Development of deep learning model, Geosci. Model Dev., 15, 715–730, https://doi.org/10.5194/gmd-15-715-2022, 2022.
Wandel, J., Quinting, J. F., & Grams, C. M. (2021). Toward a Systematic Evaluation of Warm Conveyor Belts in Numerical Weather Prediction and Climate Models. Part II: Verification of Operational Reforecasts. Journal of the Atmospheric Sciences, 78(12), 3965-3982
An application of seasonal forecasts to the study of extreme meteorological events: the case of drought.
Authors: Buccellato Marco , Ruggieri Paolo , Porcù Federico
Published: July 2023

Characterizing hydrometeorological extreme events can be hampered by the limited availability of observations of past meteorological conditions. Seasonal forecasts, which are commonly used to represent the temporal evolution of the predictable components of the Earth system over periods of a few weeks or months, have been recently applied to obtain information about extreme events and their dynamical drivers: indeed, they have a spatial resolution which is generally higher than that of climate projections and they can be used in order to get a better description of the complex and non-linear interactions taking place between the individual components of the Earth system. In this work, an application of seasonal forecast for the study of meteorological drought over Europe is presented. The paper is organized in three steps. First of all, the realism of simulations provided by C3S multi-system seasonal forecasts is assessed through a bias correction method and a statistical characterization. Then, it is shown how the applied method allows an estimate of the probability of new precipitation deficit which is consistent with that obtained from observations alone over the period 1993-2022 and that presents a markedly reduced uncertainty. At last, the investigation of the 500 hPa geopotential anomaly associated with the most intense meteorological drought events simulated by the model suggests that seasonal forecasts can be a powerful tool to better understand the dynamical drivers of climate extremes at the regional scale and the role played by the involved teleconnections, as highlighted by the similarity with the circulation pattern of the 2022 spring-summer drought event.
Multiple scenarios of climate anomalies over Europe in ensemble seasonal forecasts
Authors: Specq Damien , Li Shan , Batté Lauriane , Viel Christian , Gayrard Frédéric
Published: July 2023

Seasonal prediction uses ensemble forecasting to sample the distribution of possible climate outcomes in the upcoming term given the slowly-varying constraints on the atmosphere. However, translating the members’ distribution of a seasonal forecast into meaningful information is a challenge climate services are often faced with. When a large ensemble spread makes the forecast difficult to interpret, highlighting the competing signals from which the uncertainty arises may bear added value to end users. In order to do so, we present an approach to extract alternative seasonal forecast scenarios over Europe (in temperature, precipitation and atmospheric circulation) from ensemble seasonal forecasts. The aim of the scenarios is to refine the ensemble analysis beyond the usual forecast products (e.g ensemble mean, tercile probabilities), and to provide additional guidance for preparation of the seasonal forecast bulletins routinely issued at Météo-France.
The seasonal forecast scenarios are determined with a hierarchical clustering of the ensemble members, based on their forecast temperature at 2-m (T2m). The dissimilarity between two members is defined from the spatial correlation between their respective maps of T2m anomalies – relative to model climatology – over a European domain (29.5°W-40.5°E; 30.5°N-70.5°N, land grid points only). The subsequent dissimilarity matrix across the ensemble feeds the clustering algorithm that groups members into clusters eventually defining the scenarios. The seasonal outcomes corresponding to these scenarios are then described through several diagnostics, e.g composites on sensible climate variables (T2m, precipitation), composites on atmospheric circulation variables (Z500, V200), and analysis through modes of variability and weather regimes. In addition, we provide a description of how scenarios diverge in the course of forecast integration and identify teleconnections related to each scenario. Finally, we also assess the skill of the seasonal forecasts assuming that only the subset of members representing the most likely scenario is retained.
This methodology has been implemented to the Copernicus Climate Change Services (C3S) real-time seasonal forecasts across the past year for experimental purposes, and it is shown to be a relevant complement for the preparation of the Météo-France operational seasonal bulletins.
An extreme weather identifier for severe weather warnings: general concept and first results
Authors: Beusch Lea , Mahlstein Irina , Nerini Daniele , Graf Urs , Bhend Jonas , Willemse Saskia , Liniger Mark A.
Published: July 2023

At MeteoSwiss, we are currently developing a modular framework to automatically identify extreme weather events that will allow us to generate a broad range of user-tailored warning products. Here, we introduce this Extreme Weather Identifier (EWI) framework in the context of public warnings, namely warning polygon proposals for forecasters to support them in issuing public warnings of high quality in a timely manner.
The EWI translates NWP ensemble forecasts into warning products – in our case, warning polygon proposals – by employing a pre-defined sequence of processing steps with configurable parameters. By applying grid-point-specific warning thresholds to each NWP ensemble member, it obtains local-scale warning information and by aggregating the underlying information in space and time, it accounts for spatio-temporal representativeness issues and facilitates communication. In a first aggregation step, the spatio-temporal representativeness issues are addressed by employing neighborhood approaches to detect extreme weather in each ensemble member individually. Subsequently, all members are evaluated jointly in order to assess the probability that the extreme weather actually takes place. Afterwards, areas exceeding a minimal probability threshold are grouped together into individual regionally-valid warning polygons. At this point, the communication-motivated aggregation to the visual scale of interest starts and all further changes simply serve the goal to produce warning products that can be easily communicated to their target audience without any additional physical justifications.
To allow the forecasters to obtain an in-depth understanding of the EWI’s proposals and thoroughly assess their quality, not only the proposals themselves will be distributed but also outcomes of key intermediate steps of the EWI’s processing sequence. Products covering the EWI’s processing steps until the communication-motivated aggregation starts are intended to be made available to forecasters in real-time towards the end of this year and we will illustrate them in this contribution with examples from past warning events.
Atmospheric conditions associated with cold East-Asian orography in climate models
Authors: D'Andrea Fabio , Portal Alice , Davini Paolo , Hamouda Mostafa E. , Pasquero Claudia
Published: July 2023

East Asia orography, i.e. the elevated Tibetan and Mongolian Plateaux, is of fundamental importance for the mid-latitude climate over the Eastern part of the continent and the Pacific. During winter it supports and strengthens the Siberian (surface-pressure) High and the East-Asia Winter Monsoon, contributing to the advection of dry and cold air over the Asian coast and the Pacific Ocean. While the role of the mechanic forcing by Asian orography has been thoroughly addressed by scientific literature, here we identify the near-surface temperature over East-Asia high plateaux as an additional and important ingredient for setting the winter climate on the lee side of the orography : a cold surface-based heat source on the elevated Asian Plateaux amplifies the atmospheric response to orography (as observed in former modelling studies), causing an intensification of the East Asia winter monsoon and a strengthening of the southern flank of the Pacific jet. This finding is based on the analysis of a composite of climate-model climatologies characterised by cold East-Asian orography (from the Coupled Model Inter-comparison Project, Phase 6 - CMIP6), and is confirmed by running simulations forced by cold land-surface temperatures over the same orographic region, using an intermediate-complexity atmospheric model in perpetual-winter conditions. Our results, ranging over different degrees of model complexity, are in line with the outcomes of a highly idealised analysis of the interaction of the atmosphere with orography and superposed heat sources, in Ringler and Cook (1999). Moreover, the problem is particularly relevant in view of the well known cold bias in state-of-the art climate models - such as the CMIP6 ensemble - in proximity of the Tibetan Plateau. T. D. Ringler and K. H. Cook. Understanding the seasonality of orographically forced stationary waves: Interaction between mechanical and thermal forcing. Journal of the atmospheric sciences, 56(9):1154–1174, 1999
Relationship between anthropogenic climate change and the rare extreme derecho convective event over the Mediterranean Sea in summer 2022?
Authors: González-Alemán Juan Jesús , Insua-Costa Damian , Bazile Eric , González-Herrero Sergi , Miglietta Mario Marcello , Groenemeijer Pieter , Donat Markus G.
Published: July 2023

A derecho is a widespread, long-lived, straight-line windstorm that is associated with a fast-moving group of severe thunderstorms known as a mesoscale convective system.
During 18 August 2022, a highly intense and organized convective storm, classified as a derecho, developed over the western Mediterranean Sea affecting Corsica, northern Italy and Austria, with wind gusts up to 62 m/s and giant hail (~11 cm). There were 12 fatalities and 106 people injured. This event received much attention in the media for its extraordinary impact and the rareness over the Mediterranean Sea. The derecho developed over an extreme marine heatwave that persisted during the whole summer. Therefore, the hypothesis of a relationship between the extreme atmospheric event and the extreme marine heatwave rapidly arose, and thus, a possible link with anthropogenic climate change.
This convective event can be considered as extreme from the affected locations point of view (in terms of winds) but also is between one of the most powerful derechos ever recorded in the USA and Europe. Also, the event developed over an extreme marine heatwave that was mainly affecting the western Mediterranean Sea during summer 2022.
Here, by performing model simulations with both the NCAR Model for Prediction Across Scales and the Météo-France nonhydrostatic operational AROME model, we find a relationship between the marine heatwave, the actual anthropogenic climate change conditions, and the development of this extremely rare and severe convective event. We also find a future worrying increase in intensity, size and duration of such an event with future climate change conditions.
An evaluation of different objective detection methods of atmospheric blockings over Southeastern Pacific and South Atlantic oceans: impact on the blocking climatology
Authors: Ferreira Vanessa , Maroneze Rafael Maroneze , Toledo Bonfim Osmar , Mortarini Luca
Published: July 2023

Episodes of atmospheric blocking over Southeastern Pacific and South Atlantic oceans significantly affect the weather over South America. In Brazil, blocking events have been associated with heat waves and droughts or abnormally dry periods. Since there is no unique definition of atmospheric blocking, different objective methods for identifying and quantifying atmospheric blocking have been developed in recent decades, primarily targeting Northern Hemisphere blocks. For this reason, the observed frequency and characteristics of blocking depend on the method adopted, leading to changes in the resultant blocking climatology. In the Southern Hemisphere, studies addressing atmospheric blocking are still scarce. More specifically, there is no study assessing the reliability of the different identification methods in the Southern Hemisphere. To address this gap, this work examines blocking properties produced by five different objective detection methods over the Southeast Pacific and Southern Atlantic oceans, using ERA5 data. The five indexes used in this study rely on the 500 hPa geopotential field and were developed by modifying the approaches employed in earlier studies by Lejeñas (1984), D’Andrea et al. (1998), Schwierz et al. (2004), Davini et al. (2012), and Mendes et al. (2022). The study also examines the variations in the blocking climatologies that arise from using different objective detection methods. Additionally, in order to evaluate the accuracy of each objective method applied, the results are compared with observed blocking episodes. Moreover, atmospheric fields are analyzed to verify if a synoptic blocking pattern was present during the objectively identified blocking events. References:D’Andrea, F. et al. Northern Hemisphere atmospheric blocking as simulated by 15 atmospheric general circulation models in the period 1979–1988. Climate Dyn., 14 (6), 383–407, 1998.Davini, P. et al. Bidimensional diagnostics, variability, and trends of Northern Hemisphere blocking. Journal of Climate, v. 25, n. 19, p. 6496-6509, 2012.Lejenãs, H. Characteristics Of Southern Hemisphere Blocking As Determined From A Time Series Of Observational Data. Q. J. Roy. Meteor. Soc., V.110, P.967-979, 1984.Mendes, M.C.D. et al. Synoptic–dynamic indicators associated with blocking events over the Southeastern Pacific and South Atlantic oceans. Climate Dynamics, p. 1-17, 2022.Schwierz C. et al. Perspicacious indicators of atmospheric blocking. Geophys Res, 2004.
Extreme weather linked to excess human mortality in projections of future climate
Authors: Plavcova Eva , Urban Ales , Hanzlikova Hana , Kysely Jan
Published: July 2023

Extreme weather events pose various significant impacts on society, including human health. The objectives of our analysis are: (1) to identify weather patterns that are associated with excess mortality, and (2) to assess how the frequency of these patterns may change in future climate scenarios using regional climate model simulations. We build upon our previous study that revealed winter extreme events linked to excess mortality and their intensified impacts from their compound occurrences (Plavcová and Urban, 2020). High-quality long-term mortality time series data from 1982 to 2020 is utilized to identify meteorological phenomena linked to significant excess mortality in the Czech Republic. Our analysis focuses on sudden changes in various meteorological parameters (such as temperature and pressure) and their compound occurrences during both winter and summer seasons.
Subsequently, we analyze projected changes in the frequencies of these extreme weather events using an ensemble of EURO-CORDEX regional climate model simulations for the end of the 21st century. We acknowledge a significant role of future adaptation of human society to changing weather conditions resulting from global climate change remains uncertain, although it plays a significant role. Nonetheless, concern for human health is one of the most compelling motivation to study the effects of climate change. Our findings provide insights into how the occurrence of weather events linked to mortality risk may evolve under future climate scenarios, and may help to develop mitigation and adaptation strategies to manage health risks linked to extreme weather. 

Plavcová E, Urban A (2020) Intensified impacts on mortality due to compound winter extremes in the Czech Republic, Sci. Total Environ., 746, Article 141033, 10.1016/j.scitotenv.2020.141033
Increasing anticyclonic influence over Central Europe between 1836–2015
Authors: Varga-Balogh Adrienn , Leelőssy Ádám , Varga László , Mészáros Róbert
Published: July 2023

Climate change has various effects in different regions on Earth. The shift of global circulation patterns, most importantly changing cyclone tracks and strengthening blocking episodes have serious influence on the regional climate in the midlatitudes. In this study, a 180-year long historical dataset was used to track the change of the circulation patterns over Europe, since different weather types and precipitation can be associated with different synoptic situations. An automated cyclone/anticyclone detection method was applied on the mean-sea level pressure data from the Twentieth Century Reanalysis Project (NOAA). The European domain was split into the areas of low and high pressure systems, thus in each location we were able to investigate the distribution of cyclonic and anticyclonic effects. Clustering methods were used to study the long-term shift of pressure centers.
In the 1836–2015 period, largely increasing anticyclonic influence can be seen in the Mediterranean, underlining the increasing risk of droughts. In the European domain, anticyclonic clusters generally shifted towards the Mediterranean, while cyclone centers showed a northward shift and a weakening tendency. However, the temporal trend of shifts was not consistent over the long study period with multiple breakpoints over the 20th century. The statistically significant increase of anticyclonic influence over the 180-year long period was between 5–10% for Central Europe and reached 10% in the Mediterranean. Increasing frequency of low-pressure systems was found in Northern Europe. Results coincide with the regional climate impacts reported in literature and highlight the importance of the investigation of changes in climate dynamics over this highly populated area.
The role of shading on biometeorological conditions in the historic centre of Prague, Czech Republic.
Authors: Chlapcová Lucie , Urban Aleš , Kyselý Jan
Published: July 2023

Prague is the capital and the largest city of the Czech Republic and its historic centre near the Vltava river is a popular tourist destination. Especially the area along the right bank of the Vltava river, called Náplavka, is one of the most popular locations to visit during the summer months due to many social and cultural events that take place here. However given the north-south orientation of the Vltava river and the lack of greenery and shade in this area, the question arises as to what extent thermal conditions are comfortable during hot summer days at Náplavka. Many previous studies have shown that the presence of greenery and shade is essential for reducing the heat stress in the streets.
In this study we assessed the effect of shading on biometeorological conditions at eight different measuring sites located along a loop between Charles Square and the Náplavka riverbank. We used a Kestrel 5400 heat stress tracker, to measure and record meteorological parameters (including air temperature, relative humidity, wind speed, Heat Index, Wet-Bulb Globe Temperature) every two hours between 8:00 a.m. and 6:00 p.m. CEST on 16 summer days from 2019 to 2022. In addition, fisheye photographs were taken at each location in order to quantify the effect of shading. From these data, we calculated advanced thermal comfort indices (Physiologically Equivalent Temperature, Universal Thermal Climate Index) and Sky View Factor (SVF) in the RayMan Pro program.
Our results showed that while in the morning Náplavka’s biometeorological conditions were most comfortable among all measurement sites, they became most stressful in the afternoon. The analysis of the fisheye images showed that the lack of greenery and shading at Náplavka contributed significantly to the high heat stress levels. Our results suggest that the relocation of day-long events from Náplavka to other locations (e.g. a park at Charles Square) should be considered and/or adequate sun protection should be provided on hot summer days.
The 2019/2020 and 2020/2021 droughts events in Southern and Southeastern Brazil
Authors: Toledo Bonfim Osmar , Ferreira Vanessa , Maroneze Rafael , Mortarini Luca
Published: July 2023

Drought is a highly intricate hazard that can be challenging to define and detect. Its impact can be felt across numerous sectors and timeframes. The configuration of La Nina conditions is linked to drought conditions in Southern and Southeast Brazil, especially during late spring and summer months. Since late 2019, two successive La Nina events have resulted in various degrees of drought in the southern region of Brazil, causing significant effects on multiple sectors such as agriculture, water resources, and energy production. The 3-month Standardized Precipitation Index (SPI) timescale was utilized to define and characterize the drought conditions. In this study, a drought event starts when the analyzed indicator falls below a certain negative standard deviation value (e.g. SPI-3 < -1) for at least two consecutive months, and ends when the indicator rises above 0, following the methodology described in Spinoni et al. (2019). The aim of this work is to examine and compare the differences between the two drought episodes that occurred during the spring and summer of 2019/2020 and 2020/2021, respectively, and to understand the variations in their severity. Four different sources of monthly precipitation data were used: the ERA-5 global reanalysis dataset, CHIRPS and PERSIANN satellite datasets, and automated weather stations from INMET. A comparison is performed among these four datasets to identify if there is an impact in drought characteristics, such as area, duration and intensities. This study also explores the impact of large-scale circulation and sea surface temperature indices, namely El Nino 3.4, Indian Ocean Dipole (IOD), South Atlantic Subtropical Dipole mode (SASD), and South Atlantic Ocean Dipole mode (SAOD), on the two recent drought episodes.
Sensitivity of simulated precipitation to different RegCM configurations over the Carpathian region in the wettest year
Authors: Kalmár Tímea , Pongrácz Rita , Pieczka Ildikó
Published: July 2023

Due to its high influence on agriculture, infrastructure, water management, and other areas, precipitation is one of the most important climate factors. Furthermore, climate change is likely to produce more extreme precipitation events and lead to an excess of surface water and floods, which have severe impacts on society. However, it is still one of the major challenges for climate models to realistically reproduce the regional patterns, temporal variability, and precipitation intensity due to the intricate interactions between atmospheric precipitation processes, including cumulus convection, large-scale circulations, planetary boundary layer processes and cloud microphysics. This is especially true for terrains with heterogeneous orography, like the Carpathian region.
For the sake of quantifying the uncertainty and improving the accuracy of the precipitation simulations of the RegCM4.7 regional climate model over the Carpathian region, we evaluate the performance of different physical options at 10 km horizontal resolution, using ERA-Interim reanalysis data as initial and boundary conditions. Altogether 24 simulations were carried out by using various combinations of the physics schemes (2 land surface, 2 microphysics, 3 cumulus and 2 boundary layer schemes) for the year 2010, which was the wettest year in the Carpathian region since the beginning of the regular measurements. Different parameterization combinations lead to different simulated climates, so their variance can serve as an estimate of model uncertainty due to the representation of unresolved phenomena.
The analysis of the RegCM ensemble indicates systematic precipitation biases, which are linked to different physical mechanisms in the summer and winter seasons. Furthermore, problematic interaction between some parameterizations causes large overestimation of the precipitation. Due to the different treatment of moisture in the schemes, there are differences not only between the representations of the precipitation cycle, but also in other climatological variables such as soil moisture, temperature and cloud cover. Based on the results, RegCM4.7 is the most sensitive to the applied convection scheme, but the interactions with the other schemes (e.g., microphysics and land surface) affect not only the total precipitation, but also the convective and stratiform precipitation in some cases.
Acknowledgements. Research leading to this study has been supported by the following sources: the Hungarian National Research, Development and Innovation Fund (under grant K-129162), and the National Multidisciplinary Laboratory for Climate Change (RRF-2.3.1-21-2022-00014).
Modelling and Evaluating the Urban Thermal Environment of Nicosia through the Combined Use of WRF and Satellite Observations
Authors: Koutroumanou-Kontosi Konstantina , Cartalis Constantinos , Hadjinicolaou Panos , Constantinidou Katiana , Agathangelidis Ilias
Published: July 2023

The Eastern Mediterranean and Middle East (EMME) region is an exceptionally thermally vulnerable area, projected to suffer from frequent and severe heat waves in the coming decades. Process-based numerical simulations of the urban climate can provide a cost-effective assessment of urban overheating with greater spatial and temporal resolution than in-situ observations. High-resolution numerical simulations are crucial to assess the impacts of climate change on the urban thermal environment in cities. In this study, the Weather Research and Forecasting (WRF) model was used to dynamically downscale the regional scale (12km) to the local scale (1km) and thus derive high-resolution data for the 2m air temperature and land surface temperature over Nicosia, Cyprus which is located in the EMME region. The simulation was driven by the ERA5 re-analysis, over a three-year period. The WRF model was coupled with the Single Layer Urban Canopy Model (SLUCM) parameterization for a better representation of the urban characteristics of Nicosia. Detailed information on the urban form was inserted into the model through the creation of the Local Climate Zones classification scheme. An evaluation of the simulation results with observation data was performed in terms of annual, monthly, and seasonal values as well as of the capability of the model to identify the urban heat island effect. Following, simulated land surface temperature and spatial patterns were compared with observations from different satellites over Nicosia. Finally, air and surface urban heat island intensity and diurnal dynamics were evaluated using in-situ measurements, reanalysis data, WRF simulations, and remotely sensed thermal observations.
Adapting energy systems to a changing climate -- The Destination Earth Use Case Energy Systems
Authors: Schyska Bruno , Kies Alexander , Hayez Léa , Ceglarz Andrzej , Medjroubi Wided , Schroedter-Homscheidt Marion
Published: July 2023

In liberalized electricity markets, the planning and operation of the electricity grids, often, is done by private companies under the control of a public authority. Following their mandates, the European transmission system operators for electricity implement, among other analyses, national grid extension plans, the Europe-wide Ten-Year Network Development Plan and the European Resources Adequacy Assessment. To achieve evidence-based decision-making, they rely on the best-available meteorological and/or climatological information on a variety of scales, from the local distribution grid level to the European transmission system, and from short-term forecasts for the operation to climate scenarios for investment decisions. Here, the capabilities of the new Destination Earth (DestinE) Digital Twin on climate adaption can make a significant impact. It is expected that the explicit modelling of physical processes on the storm- and cloud-resolving scale also leads to a more realistic and accurate representation of the solar and wind resources. This offers great opportunities for improved energy system modelling and opens the door for new innovative approaches for adding the analysis of climate information into standard modelling workflows applied in the energy sector. However, there is a lack of knowledge about available meteorological data sets, their characteristics and the implications of using different data sets for grid planning and adequacy assessment activities in the user community. Standardized tools and methods to add the analysis of climate change and/or climate uncertainty to user workflows rarely exist. This hinders energy system modelers to make full use of the available meteorological information and, consequently, prevents users from tapping the full potential of the data. As energy systems become more dependent on weather, and as the uncertainties about climate change impacts rise, the operation and planning of integrated energy systems becomes an increasingly complex task.
Aim of this presentation is the introduction of a DestinE Use Case for the energy sector jointly implemented by DLR, the Renewables Grid Initiative and Aarhus University. By developing and implementing a representative Demonstrator exemplarily showcasing the use of climate information in the energy sector for grid planning and resources adequacy assessment purposes, this Use Case will make a valuable contribution to the co-design of energy and climate models. Furthermore, the user community will be equipped with the tools, methods and the knowledge needed to ensure the safe and clean supply of energy in Europe in accordance with the Nationally Determined Contributions to the Paris Agreement and the European Union’s “Fit for 55” goals. Overall, our Use Case shall further strengthen the collaboration between the climate sciences, the energy systems analysis and the end-users from the energy sector.
Aerosol-layer structure and wind profile in the high Arctic
Authors: Gryning Sven-Erik , Batchvarova Ekaterina , Floors Rogier , Muenkel Christoph , Sørensen Lise Lotte , Skov Henrik
Published: July 2023

We present an investigation of the structure of the aerosol layer at the Villum Research Station located at Station Nord in the high Arctic. Knowledge of the aerosol layering is of interest for the interpretation of measurements of atmospheric chemistry and particles that control air pollution in the pristine atmosphere and for climate change (Arctic amplification). Based on one year of remote sensing measurements by a ceilometer and a wind lidar, we discovered that the structure of the atmosphere was very different from what is usually found at mid-latitudes. Combining the ceilometer and wind lidar observations indicated that the aerosol layer has depths of about 100 m and 230 m and few cases of depth between 100 and 230 m. Studies of profiles with no aerosol-layer depth, based on high frequency ceilometer observations, reveal cases of entraining air. We found that the annual wind roses indicate generally westerly wind veering by more than 30 degrees between 40 and 200 m and a wind speed slowly increasing with height of about 5 m/s. It was found that the individual wind speed profiles between 40 and 200 m can roughly be categorized into 4 groups: 1. The wind speed increases from the ground up to 100m and thereafter decreasing (likely drainage); 2. The wind profile decreases from the ground up to a minimum at about 100 m; above this minimum the wind speed increases (no explanation for this type of wind profile is offered); 3. Wind speed increases with altitude; 4. Wind speed decreases from the ground throughout the whole layer. The two-layer structure of the aerosols and the different categories of wind profiles complicates the interpretation of surface observations. We discuss the implication in terms of local versus remote sources of aerosols and the uncertainty in backward trajectory modelling. These data can be used further for meteorological and aerosol model validation in the lower atmosphere of the High Arctic.Funding information: Danish Environmental Agency ‘Monitoring of short-lived climate components in Arctic’; European Cooperation in Science and Technology, Grant/Award Number: COST Action CA18235 PROBE; National Science Fund of Bulgaria, Grant/Award Number: KП-06-Н34/1; Nationalt Udvalg for Forskningsinfrastruktur (NUFI) 
Micrometeorological measurements and data management as transferrable skills
Authors: Lalic Branislava , Firanj Sremac Ana
Published: July 2023

In a fast-changing global economy, possessing knowledge and skills plays a crucial role in determining individual, institutional, and societal competitiveness and the capacity to drive innovation. The FAIR Micromet Portal FMP2.0  (Roantree et al., 2023;  denoted as FKP) and CA20108 FAIRNESS network aim to enhance transferable skills in measurement planning and implementation challenges (creative thinking and problem-solving) and interdisciplinary approaches (the ability to combine work across different fields), with the expectation of improved outcomes.
 
These skills are highly valued by employers and in great demand in the labor market, making them important drivers of individual career development. However, there often exists a significant diversity among Ph.D. students and new employees (young researchers) regarding functional knowledge and skills, which may result in certain gaps. Identifying whether these gaps relate to soft, hard, or transferable knowledge and skills is essential. A lack of transferable skills can significantly hinder further career development. To address this issue, we have designed a transferrable skills questionnaire to help young researchers and experts assess their transferable skills related to micrometeorological measurements and decide which ones to enhance. The selected skills include micrometeorological instrumentation (principles of work, selection and installation), experiment design (designing micrometeorological measurements in rural and urban areas; anticipating and overcoming the most frequent issues; data and metadata selection), data assimilation (managing different data formats and units), critical control (quality control; identifying different data gaps in micrometeorological data and metadata), and gap filling (different methodologies in filling gaps in data and metadata).
In this study, we present the results of the self-assessment of the first hundred participants.
Literature
Roantree, M., Lalic, B., Savic, S., Milosevic, D., and Scriney, M., 2023: Constructing a Searchable Knowledge Repository for FAIR Climate Data, EGU General Assembly2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7786. https://doi.org/10.5194/egusphere-egu23-7786.

 
Homogenization of the global historical database (HCLIM)
Authors: Lundstad Elin , Hygen Hans Olav
Published: July 2023

Homogenization of the global historical database (HCLIM)Instrumental meteorological observations are crucial for the analysis of climate backwards in time to reconstruct climate variations. However, the collection of instrumental data dating back to 1658 allows many of the long climate series to have often been affected by inhomogeneities (artificial shifts) due to changes in measurement conditions (relocations, instrumentation, change in environment, etc.). To deal with this problem, modern homogenization procedures have been used and developed to detect and adjust inhomogeneities. Homogenization in climate research means the removal of non-climatic changes. This presentation describes the homogenization of the early instrumental dataset (HCLIM; https://doi.pangaea.de/10.1594/PANGAEA.940724) of monthly mean temperature time series. New homogenization algorithm validation methodology is assessed here on early instrumental data, and its use to assess the skill of three different algorithms, when applied to early instrumental data. The methods tested were PHA, BART and CLIMATOL. Results and challenges of using these methods on early instrumental data will be shown. From the database that has been created (published January 2023), it has been necessary to clean up the data and at the same time use the data to see what strengths and weaknesses exist with the database. The clean-up has consisted of changing the data format for use for homogenisation, and testing latitude, longitude and meters above sea level and the possibility of obtaining verified data for comparison. You can also see that there is some data that cannot be used for this purpose. Something can be used for completely different purposes, e.g., finding extremes. It has also been a learning process to use these homogenization programs.
A pre-operational hail impact assessment platform for multiple sectors in Switzerland
Authors: Villiger Leonie , Schmid Timo , Portmann Raphael , Calanca Pierluigi , Bresch David N.
Published: July 2023

Hail poses a significant risk to buildings, cars, and crops, making accurate hail impact assessments critical for decision makers in the insurance industry and agricultural sector. Here, we introduce a pre-operational hail impact assessment platform for Switzerland and multiple sectors that is co-created with potential end-users in the context of the project seamless coupling of kilometer-resolution weather predictions and climate simulations with hail impact assessments for multiple sectors (scClim, https://scclim.ethz.ch/). The platform provides both hindcasts and forecasts of hail impacts. The underlying hail damage models were developed with the open-source, event-based risk modeling platform CLIMADA (https://wcr.ethz.ch/research/climada.html). The applied vulnerability curves for buildings, cars, and crops were calibrated with damage data from 2002 to 2021, which was obtained from insurance companies. To assess hail damages from the previous day, the models rely on daily radar-based estimates of the maximum expected severe hail size (MESHS) or crowd-sourced hail reports gathered through a mobile application. To forecast hail damages in the upcoming day, the models utilize the output generated by the HAILCAST hail growth model, which is integrated into the numerical weather forecasting model COSMO. The COSMO model is operated in an ensemble configuration consisting of 11 members, allowing probabilistic short-term forecasts. The platform's first prototype was tested by stakeholders during the summer of 2023 to identify the most valuable content and presentation methods. Through this ongoing collaboration, we aim to create a comprehensive platform that addresses the various needs of stakeholders and enables them to make informed decisions when facing hail risks.
Simplicity and complexity trade-offs in modelling urban-atmosphere
Authors: Grimmond Sue
Published: July 2023

Over the last 40 years enormous progress has been made in modelling urban surface to atmosphere exchanges with huge advances in the understanding of the weather and climate of cities. This has been stimulated by greatly increased attention on urban areas as places where people live and sites of some of the most extreme modifications of the environment; by improved instrumentation and measurement campaigns which have enhanced our understanding of key processes and their controls; enhanced conceptual and theoretical frameworks to make sense of what we measure and to underpin numerical models; and computer power which has allowed us to analyse and visualise high resolution data and to model at higher spatial and temporal resolutions. As we move from forecasting to delivering services to a broad array of end-users and  communities, the level of detail needed (about the urban surface and the urban atmosphere), both spatially (across and between cities) and temporally (from events to long term simulations) also has increased and has refocused attention on how best to captured the details of the dynamics of urban environments and the inherent trade-offs between complexity and simplicity of approaches. In this talk, I will address some of these changes, highlighting the  challenges we are trying to address today.
High-frequency, year-round time series of the carbonate chemistry in a high-Arctic fjord (Svalbard)
Authors: Gattuso Jean-Pierre , Alliouane Samir , Fischer Philipp
Published: July 2023

Abstract. The Arctic Ocean is subject to high rates of ocean warming and acidification, with critical implications for marine organisms as well as ecosystems
and the services they provide. Carbonate system data in the Arctic realm are spotty in space and time, and, until recently, there was no time-series
station measuring the carbonate chemistry at high frequency in this region, particularly in coastal waters. We report here on the first
high-frequency (1 h), multi-year (5 years) dataset of salinity, temperature, CO2 partial pressure
(pCO2) and pH at a coastal site (bottom depth of 12 m) in a high-Arctic fjord (Kongsfjorden, Svalbard). Discrete measurements of
dissolved inorganic carbon and total alkalinity were also performed. We show that (1) the choice of formulations for calculating the dissociation
constants of the carbonic acid remains unsettled for polar waters, (2) the water column is generally somewhat stratified despite the shallow depth,
(3) the saturation state of calcium carbonate is subject to large seasonal changes but never reaches undersaturation (Ωa ranges
between 1.4 and 3.0) and (4) pCO2 is lower than atmospheric CO2 at all seasons, making this site a sink for
atmospheric CO2 (−9 to −16.8 molCO2m-2yr-1, depending on the parameterisation of the gas transfer
velocity). Data are available on PANGAEA: https://doi.org/10.1594/PANGAEA.960131 (Gattuso et al., 2023a).