bluuebunny/crossref_metadata_2025 huggingface dataset:
Interpolating intraday precipitation data with radar background information
Authors: Izsák Beatrix , Bokros Kinga , Bihari Zita
Published: July 2023

It is a common phenomenon that a small but significant precipitation cell or supercell passes between two measuring stations, resulting in an inadequate record of the daily precipitation amounts of up to 100 mm falling on a small area between the measurements and observations. This renders the interpolation from measurements alone insufficient to provide a complete depiction of the actual weather conditions. Therefore, to reduce the deviations from the actual weather situation, supplementary background information, for instance satellite data series, forecast information or radar measurements is used. In many cases, heavy thunderstorms with high rainfall can cause flash floods, which have a number of known negative effects in both social and agricultural areas. To achieve more accurate interpolation, it is therefore essential to use radar background information, as it yields significant social and agricultural benefits and can even be used for hazard warning. As the annual, seasonal and daily precipitation sum data series are interpolated using the MISH software at the OMSZ (Hungarian Meteorological Service) Unit of Climatology, the 10-minute, hourly, etc. precipitation sums are also interpolated using the MISH system. MISH software incorporates background information automatically and produce verification statistics. In our presentation, we will not only illustrate the theoretical and practical application of the MISH software, but also provide an overview of these statistics. The data series were interpolated by MISH for the whole area of Hungary, with and without radar background information, and statistical methods were used to illustrate the extent to which the interpolation was improved by the radar product used as background, and the strong relationship between interpolation with and without background information.
Acknowledgement:
The research presented in the article was carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF 2.3.1 21 2022 00008 project.
Experiences of the LIFE URBANKLIMA2050 Project: Climate Change Scenarios for the Basque Country
Authors: Martija-Díez Maialen , Hernández Roberto , Iza Maddalen , Gómez de Segura José Daniel , Gaztelumendi Santiago
Published: July 2023

UrbanKlima2050 is the most ambitious initiative led by the Basque Country that aims to ensure the resilience of the territory through multi-level governance and climate action on the ground. This large-scale Integrated Life Project was launched at the end of 2019 thanks to a partnership of 20 organizations and an investment of 19.8 million euros. The project partners have set themselves the ambitious goal of implementing different actions over 6 years, influencing more than 2 million people. The main objective of the UrbanKlima2050 project is to contribute to the full implementation of the Basque Climate Change Strategy 2050, developing a low-carbon and climate-resilient region by 2050.
The project's actions are grouped into five main blocks: (1) Analyse: review the Basque KLIMA 2050 strategy through monitoring and evaluation, with a focus on continuous improvement; (2) Define: how, where and when to act to reduce GHG emissions and achieve territorial resilience; (3) Act: implement pilot projects at three levels of intervention: coast, river basins and urban/peri-urban areas, scalable to other areas of the Basque Country and other regions; (4) Empower: promote climate awareness among government institutions and the community and move them to action; (5) Manage: create structures to facilitate climate governance and climate change observation and monitoring, in addition to defining new models of climate governance and launching the Hub for climate change observation and monitoring in the Basque Country
Tecnalia participates in twelve actions, leading five of them. Here we focus on those aspects related to action A.2. "Extension of the risk analysis in the Basque Country", led by Basque Environmental Agency (IHOBE), where different activities are carried out by Tecnalia, Neiker and other agents in order to establish high-resolution climate change scenarios for the Basque Country
Among other tasks, in this project line, the Tecnalia weather and climate area is tackling the complementation of the results gathered in previous Klimatek projects, in which different downscaling exercises were carried out including climate projections for temperature, precipitation and various associated climate indices, on a 1 km resolution grid. One of the objectives of the current project is to address other variables such as average wind, relative humidity and radiation.
In this contribution, different results of one of the lines developed are presented, in particular, the one in which a high-resolution observational database is used for the implementation of bias correction to EURO-CORDEX climate projections of wind, humidity and radiation, by means of different statistical techniques. Likewise, the different methodologies used for its interpolation to a high-resolution grid (1km ) are included. Finally, the most relevant conclusions of the work undertaken are presented, as well as a proposal for future lines of action.
An air quality multi-model prediction system for the Basque Country
Authors: Diaz de Arcaya Aurelio , R. Gelpi Ivan , Arrillaga Jon Ander , Castaño Antonio , Gaztelumendi Santiago
Published: July 2023

In this work, we present a system developed by Tecnalia and Euskalmet for air quality forecast at local level, the system runs since 2019 in order to provide different air quality products to support some operational task in Basque Meteorology Agency (Euskalmet).  
The air quality prediction multi-model system developed is based on two main modelization strategies, one using CHIMERE and another one based on WRF-CHEM.  The system  have been implemented for the hourly prediction of air quality for the pollutants CO, NO2, O3, PM10, PM2.5 and SO2 in the domain of the Basque Country. Both models are executed daily with a prediction horizon of up to 4 days and with resolutions around 1 km. In the case of the CHIMERE chemical transport model, four nested domains are considered, being the coarser domain Western Europe and the finer one the Autonomous Community of the Basque Country (CAE), WRF model meteorological fields are included offline. In the case of WRF-CHEM, three nested domains are implemented, the first one being Western Europe and the last one the CAE, in this case meteorology given by the WRF model and the pollutant transport module, are executed online. In both cases, the WRF meteorological model starts from the initial and boundary conditions given by the one-degree GFS global prediction model. The emissions used by both models are those given by the EMEP emissions inventory for the CHIMERE model and EDGAR for the anthropogenic emissions required by WRF-CHEM. Subsequently, for the domain of the Autonomous Community of the Basque Country, a proprietary emissions inventory has been used.
In this contribution, main results of the implementation of the system are shown, including post-processing, products generation and validation. Finally, some conclusions from pre-operational and operational experiences are presented.
The Climate Mill, an infrastructure for processing climate data
Authors: Tunheim Ketil , Verpe Dyrrdal Anita , Hygen Hans Olav
Published: July 2023

The societal needs for updated and downscaled climate projections for adaptation action are well documented. These needs range from key information and recommendations, such as fact sheets targeted at municipalities, to geographic information and even access to the full datasets of climate projections. 
All the while the climate research community is producing global and regional projections of increasingly higher quality. More and more national climate service instances produce further downscaled and bias-adjusted national projections, sometimes even separate hydrological projections, to produce more locally relevant information. 
The sheer amounts of data are enormous and require significant capacity for storage and data transfer. This leads to climate and climate impact scientists spending a significant amount of time handling the data, and this effort is often duplicated even in the office next door.
To alleviate this problem, the Norwegian government has granted MET Norway a project to create an integrated infrastructure for storing, processing, and distribution of downscaled and bias-corrected climate projections. This infrastructure, and the project, is called the Climate Mill, Klimakverna in Norwegian. The project has a 4 year timeframe, starting 2023 with planning and mapping of technologies. One of the keystones in the Climate Mill is FAIR metadata that follows the data through the entire process. This metadata will ensure compatibility with  Geonorge, a national portal for geodata, thus simplifying the distribution. The infrastructure will rely on existing technologies including cloud solutions for storage and processing. With this we aim to make climate projections easier to produce, and ultimately easier to use for adaptation purposes.
Wind lidars within Dutch offshore wind farms
Authors: Knoop Steven , de Jong Mando
Published: July 2023

The growing number of wind farms in the Dutch part of the North Sea [1] offers the necessity, as well as the opportunity, to measure the meteorological conditions at these locations. Wind lidars are deployed on the TenneT substations within those wind farms, to continuously measure the wind conditions. These measurements can be used to determine possible compensations if the offshore electricity net should be unavailable, but also for nowcasting and improvement of weather forecasts, to increase efficiency of the wind turbines, or wind climatological purposes. The Royal Netherlands Meteorological Institute (KNMI) acquires the wind lidar data and makes it available near-real time to specific users, such as the wind farm owners and KNMI operational weather forecasters, and publicly on a daily basis [2].
The first wind lidar within this network became operational in the summer of 2019 and since then four more wind lidars became active within wind farms Borssele, Hollandse Kust Zuid and Hollandse Kust Noord (all about 20 km from the Dutch west coast).  Five more wind farms, 50km to 100km from the coast, are planned in the next four years [1], within which wind lidars will be deployed as well. The current instrument is the ZX300M vertical profiling wind lidar (ZX lidars), measuring wind speed and wind direction in a range of 10m to 200m above the instrument. Theses wind lidars are installed on the roof deck of the offshore substations, 40m to 45m above mean sea level. In 2018-2020 KNMI carried out an intercomparison of a ZX300M wind lidar and wind measurements in the 213m tall meteorological mast at our Cabauw site [3], and a ZX300M firmware intercomparison was conducted in 2020 [4].
In this presentation we give an overview of the current and upcoming wind lidar network, and the data retrieved so far. We present a study on the flow distortion caused by the substation, which affects the wind lidar measurements in the first 50m above the substation.  Most importantly, the wind lidars are deployed the middle of wind farms, such that the wind profiles are disturbed, in particular around the wind turbine hub heights. To assess this effect we have compared wind lidar data before and after Borssele wind farm became operational, together with the HARMONIE-AROME weather model with and without wind farm parameterization [5].
[1] https://www.noordzeeloket.nl/en/functions-and-use/offshore-wind-energy/
[2] https://dataplatform.knmi.nl/dataset/windlidar-nz-wp-platform-10min-1 and https://dataplatform.knmi.nl/dataset/windlidar-nz-wp-platform-1s-1
[3] Knoop, S., Bosveld, F. C., de Haij, M. J., and Apituley, A.: A 2-year intercomparison of continuous-wave focusing wind lidar and tall mast wind measurements at Cabauw, Atmos. Meas. Tech., 14, 2219–2235, 2021, https://doi.org/10.5194/amt-14-2219-2021
[4] Knoop, S.: ZephIR 300M wind lidar firmware intercomparison, KNMI Internal report IR-2021-01, https://cdn.knmi.nl/knmi/pdf/bibliotheek/knmipubIR/IR2021-01.pdf
[5] https://wins50.nl/
Evaluation of ABL parameterization methods in ICON over the Swiss Plateau
Authors: Singh Shweta , Schmidli Juerg
Published: July 2023

Atmospheric Boundary Layer (ABL) processes directly influence the transport, diffusion and storage of passive tracers, such as greenhouse gases (GHGs). On a regional scale, local advection and mixing can modulate the vertical distribution of these trace gases. To test and optimise the representation of vertical mixing in numerical models, ICON hindcast simulations with a model grid spacing of 1 km have been performed over the Swiss Plateau for selected weather situations. These simulations are further evaluated against surface station and profiler observations and tower measurements at two the sites on Swiss Plateau namely Payerne and Beromüsnter, the latter is a tall tower (with a height of 212m) with measurements at five inlet heights. The simulations have been done with different configurations of the operational turbulence scheme in ICON, based on a 1D Turbulent Kinetic Energy equation (NWP turbulence), and with a newly developed turbulence scheme, based on prognostic equations for two energies turbulence (2TE+APDF). Results for the stable wintertime situation show that with the 2TE+APDF scheme, the fog becomes more persistent in the model and agrees better with the observations. The better skill of the 2TE+APDF scheme is partly attributed to an improved turbulence length scale formulation leading to a better representation of boundary layer top entrainment. This improved simulation of the stable boundary layer profiles will also be relevant for an improved simulation of periods with high air pollution and GHG concentrations. The results show that the 2TE+APDF scheme performs similar to or better than the combination of operational turbulence and shallow convection scheme in ICON for stable boundary layers.
Normalisation of Thermal Indices in the Context of Urban Environments
Authors: Gangwisch Marcel , Matzarakis Andreas
Published: July 2023

Global climate change and its thermal implications on cities makes it necessary to react with long- and short-term climate-adapted urban planning and action. This should be organised and implemented by municipalities as part of heat action plans, to minimise future risks of overheated city districts on the city dwellers and especially on vulnerable groups. The evaluation of the thermal impact, based on thermal indices (depicting human thermoregulation) is most important in order to allow for a safe and risk-minimised but also human-adapted urban planning. Out of more than 200 thermal indices, the three most important ones have emerged in the literature (Physiologically Equivalent Temperature, Universal Thermal Climate Index and Perceived Temperature). These indices contain the complete energy balance equation of a human body under prevailing meteorological conditions.
This contribution demonstrates the thermal vulnerabilities, strengths and similarities of the indices. Min-Max-Normalisation was applied to relate and spatially compare the indices, independently of the physical unit and range. Subsequent regression analysis revealed the relationship between each index in turn. In this context, the indices were calculated for the urban district Rieselfeld in Freiburg, Germany, using the numerical, urban microscale model SkyHelios. The model is suitable to predict the meteorological outdoor conditions of future building- and local climate- scenarios.
Our investigation showed that the different thermal indices are not so different and differ mainly in the areas where the modification of radiation and wind is most prominent. These are also precisely the zones in which automated clothing becomes a key driving factor and differs among the indices.
We want to emphasise, that in future it will be necessary to compare not only the thermal indices with each other, but also the underlying implementations of the indices and the higher-level urban microscale models. This will increase confidence of these models, providing additional information for future action in heat action plans.
Weather-dependent climate change
Authors: Goessling Helge
Published: July 2023

Climate is defined by the statistics of the weather. We are thus used to the notion that weather depends on climate in the sense that a weather state is a quasi-random realization drawn from the climatological distribution of weather states. Consequently, weather obviously also depends on climate change. Here it is argued that it can be very instructive to consider this dependence the other way around and to investigate how climate change depends on the weather. More specifically, the question is how different parts of the climatological distribution change, depending on certain relevant characteristics of the weather. For example, one may ask how the climate at some time of the year and at some location changes between a pre-industrial and a globally +4K warmer climate, considering only days where the local winds at some height blow from a specific direction. Alternatively, one may investigate how the climate change pattern differs between certain large-scale atmospheric circulation regimes, such as NAO+ and NAO- situations. While such conditional climate change analyses can be based for example on reanalysis or CMIP-type climate model data, a more extreme variant are storyline simulations where the evolution of the large-scale circulation is imposed in a climate model using different climate backgrounds, allowing to assess climate change conditional on a specific evolution of the large-scale circulation. Storyline simulations inevitably ignore possible changes in the likelihood of circulation patters. In contrast, analyses based on sufficiently large samples of reanalysis or CMIP-type data also allow for quantifying changes in likelihoods and constitute a proper decomposition of the complete (unconditional) climate change signal. Here the concept of weather-dependent climate change is described and its potential to help unravel the complexities of climate change is demonstrated.
Progress on the implementation of the ECMWF Open Data roadmap and its challenges
Authors: Parodi Ilaria , Kuilman Maartje , Pidduck Emma , Bennett Victoria , Yang Xiaobo , Modigliani Umberto
Published: July 2023

The European Centre for Medium-Range Weather Forecasts (ECMWF) is a major provider of weather information, and its products and weather data contribute to a broad range of activities in service provision and research. The use of this data is also crucial for the activities of protection of life and property by National Weather Services and, in case of emergencies, humanitarian agencies. 
ECMWF recognises that open data is an essential tool to maximise socio-economic benefits of investments in weather and climate data production. Open data is also important to promote shared actions to mitigate the effects of climate change. 
ECMWF has agreed a move to an open data policy, and this is taking place gradually. Over the last few years, a number of steps have been taken, such as: 

Applying the Creative Commons CC-BY-4 licence to all non-valid (historical) data in the Archive Catalogue for MARS as well as to static charts, 
Reducing the information cost for data, 
Introducing a limited redistribution scheme, 
Introducing small business discount for micro-organisations 
Releasing a subset of the real-time catalogue with open data policy and available through a free access service with supporting software and tools to adapt to FAIR principles. 

The process toward an open data policy presents different challenges, for example the aspect connected to the reduction in the information cost revenue, but also the growing amount of data volume that will be served, leading to the need for an improvement of the types of accesses to data, the need to guarantee data interoperability, and the need for the data to be distributed together with the appropriate documentation and self-help information, to help the users to process data, derive information and form valuable conclusions. 
ECMWF is committed to continue proceeding further towards an open data policy in the coming years. We will illustrate the proposed changes and associated challenges related to this transition, such as new open datasets and reductions in the cost of data. The general aim of these changes is to continue promoting collaboration, innovation, and advancement within the meteorological and climate science communities while aligning with WMO guidelines.
Hot and Cold spots identification through mobile measurements during warm season in main urban areas from North-Eastern Romania
Authors: Ichim Pavel , Sfîcă Lucian , Bistricean Petruț-Ionel , Crețu Claudiu-Ștefănel , Hrițac Robert , Roșu Lucian-Ionuț , Corocăescu Alexandru-Constantin
Published: July 2023

This study aims to identify hot and cold spots in the distribution of air temperature for the most important six cities from the north-eastern Romania (Iași, Bacău, Botoșani, Suceava, Piatra-Neamț and Vaslui), during the warm semester of the year. The analysis of hot and cold spots in the analyzed cities was conducted on data resulted from mobile measurements performed with Meteotracker (MT) mini weather station.
The mobile measurements were carried out under calm atmospheric conditions, with clear or partly cloudy skies, and moderate wind at three moments during the day (morning - before sunrise, noon, and evening - immediately after sunset). From May to September 2022, 80 mobile measurements were made summing up 160 hours of observation. The methodological approach involved conducting mobile measurements that cross both the central area of the cities and the peri-urban and rural areas that are not influenced by urban climate conditions. All mobile measurements started and ended in the same point so that the thermal gradient per minute could be calculated. For hot and cold spots identification, the global autocorrelation analysis method (Moran Index) was used. This analysis aims to identify areas with values that are much warmer (hot spots)/colder (cold spots) than those in neighbouring areas. The relationship between the identified hot and cold spots and imperviousness ratio (IMD) and morphometric conditions was also analysed for each city.
From this analysis, it can be observed that the occurrence of hot spots is more related to high IMD ratios, while cold spots are shaped mainly by topographic conditions. Moreover, hot spots - with a confidence level of 99% - are more frequent in the morning and evening in specific urban regions with IMD values greater than 80%. The analysis results could be useful for stakeholders involved in the mitigation of the urban heat island effect, helping them to identify the regions that risk to be excessively warm during summer in the city.
Acknowledgement: This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS - UEFISCDI, project number PN-III-P1-1.1-TE-2021-0882, within PNCDI III.
Future exposure of Portuguese viticulture to weather extremes
Authors: Fonseca André , Andrade Cristina , Claro André , Fraga Hélder , A. Santos João
Published: July 2023

Grape berries and their yields can be strongly affected by the complex connections and interactions between the grapevines and the conditions of the local environment. In areas of known wine production, the yield and quality are usually improved by considering the climate, planting the best grape variety, and using specific agricultural techniques. Thus, sustainability in the winemaking sector worldwide is under pressure due to ongoing climate change, requiring adaptation at multiple levels. Portuguese vineyards will experience increasingly dry and warm conditions due to climate change, with varying degrees of intensity and frequency of weather extremes. Nevertheless, the potential effects of these extraordinary occasions and their effects on viticulture in the future are not well known. In this research, we calculated seventeen climate extreme indices for the Portuguese wine denomination of origin regions/subregions in the historical period (1981–2010) and future periods (2041–2070 and 2071–2100), under the Representative Concentration Pathway 8.5, and based on a five-member ensemble of Regional Climate Model-Global Climate Model chain simulations. Moreover, a principal component analysis was performed for both precipitation and temperature extremes independent of each other. All of Portugal's wine regions experienced an increase in temperature extremes, predominantly in the westernmost regions. When it comes to the precipitation extremes, they show a decrease in the future and a general decline in precipitation but still are a major risk in the northeastern regions. In contrast, the dry extremes, likely bringing on severe droughts, will become much stronger. Finally, it was then possible to recognize which wine regions will be the most vulnerable to extreme weather conditions in the future. This information is essential for enabling smarter choices in the sector, including for long-term planning, climate change adaptation and risk reduction.
Acknowledgments: Soil recover for a healthy food and quality of life (SoilRec4+Health). Projeto cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do Programa Operacional Regional do Norte (NORTE-01-0145-FEDER-000083).
Evaluation of global solar radiation and cloud cover variability in northern Antarctic Peninsula
Authors: Szymszová Simona , Láska Kamil , Kim Seong-Joong , Park Sang-Jong
Published: July 2023

The Antarctic Peninsula (AP) region is well known for high variability of atmospheric parameters compared to the central part of Antarctica. This area is influenced by high cyclonic activity which results in high cloud cover and strong surface wind. Due to complex orography and the effect of AP mountains, different amount of cloud cover occurs along western and eastern coast. As the cloud cover is one of the most important atmospheric factors affecting the Earth's energy budget, its changes cause significant spatiotemporal variability of incoming solar radiation. Solar radiation is a key driver of many physical and biological processes in Antarctic ecosystems, as well as the main component of surface net radiation. Together with other radiative fluxes and atmospheric transmittance is frequently used in many atmospheric and glaciological simulations. To study annual and seasonal differences in global solar radiation (GR), measurements of shortwave downward fluxes were carried out at J.G. Mendel station (JGM) located on the north-eastern side of the peninsula and King Sejong station (KSJ) on the western side of AP. The GR monitoring was undertaken with class A pyranometers in the period 2011–2016. Furthermore, theoretical intensity of GR was calculated using radiative transfer model and used for estimation of cloud modification factor at both stations. Factors influencing the GR variability were retrieved from ERA5 reanalysis, consisting of the following parameters: surface pressure, surface albedo, water vapor, cloud cover and total ozone column (Ozone Monitoring Instrument). The results showed significantly higher intensity of GR (up to ~30.5 %) and higher values of cloud modification factor (~28.5 %) at JGM station compared to KSJ station. The main factor influencing daily variation in GR was solar zenith angle at both stations (~50 % of variability). The influence of cloud cover, main atmospheric factor, was more pronounced at JGM station (~22 %) compared to KSJ station (~15 %), while water vapor was less important compared to cloud cover (~7 % at JGM and ~17 % at KSJ station respectively).
Analysis of the severe thunderstorm in Croatia on September 15th 2022.
Authors: Mikuš Jurković Petra , Renko Tanja , Kozaric Tomislav , Kalin Lovro , Pirak Tomislav
Published: July 2023

On September 15th 2022, in the afternoon hours, central part of Croatia was hit by a violent thunderstorm, with gale-  and possibly hurricane-force winds, hail and heavy rain - and caused severe damage to properties and particularly to the forests. Testimonies of local witnesses pointed even to possibility of occurence of a tornado. A comprehensive synoptic and mesoscale analysis was performed, including radiosounding, satelite and new radar observations from the recently established radar network.  
Synoptic situation was characterized by the passage of a cold front, bringing cold air in the upper layers of atmosphere which enhanced  atmospheric instabiliy. Sounding analysis pointed out high value of most unstable convective available potential energy, accompanied by pronounced deep layer wind shear, as well as significant low layer shear (0-1 km) which is quite favorable for the formation of a tornado. Severity of the phenomenon was confirmed by lightning and satelite measurements (overshooting tops) and particularly by the radar image, pointing to hail areas and exhibiting so-called 'bow-apex' feature, indicating development of a supercell. 
In order to clarify some doubts - for the first time in our practice – a detailed in situ inspection of damaged area was also carried out, and aerial footage was also consulted. Although the atmospheric conditions were prone to development of a tornado, no material proof lead to presence of a tornado vortex, since no evidence of wind spinnig was found, and trees were usually knocked down in the same direction. 
The risk for severe thunderstorm activity was well forecasted, and corresponding operational alert was issued by the Met Service. Furthermore – as an early warning for the incoming weather change - a special announcement was issued on our web page. 
Atmospheric blockings and downstream cyclones in the Euro-Mediterranean sector
Authors: Loizou Pinelopi , Raveh-Rubin Shira
Published: July 2023

Weather extremes in Europe and the Mediterranean can have a significant effect on societies across the region. These weather extremes include heatwaves, cold spells, windstorms, and intense rainfall events. In a climate that is continuously changing, their impact, both socio-economically and environmentally, can worsen with an increase in the frequency and intensity of these extremes. As recent studies have highlighted, some extremes such as heatwaves in the northern hemisphere are connected to atmospheric blocking, while heavy precipitation has been associated with intense cyclones occurring in the Mediterranean basin which are more commonly known as Mediterranean Cyclones (MCs). However, the connection between atmospheric blocking and MCs is still understudied, despite evidence suggesting their mutual importance for exacerbating and synchronizing surface extremes. The aim of the present study is the systematic investigation of how often MCs develop downstream of atmospheric blocks over the Euro-Atlantic region, and how the Atlantic storm track is modulated under such conditions. To this end we employ the combined ‘best tracks’ MCs dataset with objectively identified (using potential vorticity anomalies) blocking features in ERA5 for the 1980-2020 period. We find that in the presence of atmospheric blocks, MCs that develop downstream tend to be more intense and more persistent than other MCs. Moreover, MCs that develop under this scenario form particular subsets of MCs, with preferred seasonality and geographical distribution, compared to all MCs. The results have important implications for the predictability of MCs and their various impacts in the region on both weather and climate time scales.
Vertical profiles of the temperature and particulate matter in Cracow and Warsaw cities – measurement campaigns results and the comparison with modelling results.
Authors: Durka Pawel , Struzewska Joanna , Kaminski Jacek W. , Posyniak Michał , Sekuła Piotr
Published: July 2023

Cities in Poland still suffer from poor air quality during winter. Most intense smog episodes, with very high PM10 and PM2.5 concentrations, occur during calm periods, with temperature inversions when the emission from residential sources with low injection height increases. Modelling results tend to underestimate those episodes, despite the good agreement with measured data during low and mid-concentration periods. While the variability of near-surface concentrations is well-known based on the fixed stations and the low-cost sensors measurements, the information on vertical distribution is limited.As measurements with drones tend to be problematic and weather balloons measure only meteorological parameters, new approaches are being developed. In Cracow (in the past one of the cities in Poland with the worst air pollution) measurement campaign with the use of sensors installed on sightseeing, hot air balloons have been carried out in 2019 to check the impact of meteorological conditions on the thickness of the atmospheric layer with poor air quality (Sekula et al., 2021).  Helium tethered aerostat (Knap et al., 2021) with installed sensors is also used by the Polish Academy of Sciences as a measurement platform for vertical profiles in Warsaw (the capital city of Poland).These two platforms were used for a short-period measurement campaign in the winter of 2023. The main goal of the project was to assess differences between modelled and observed vertical profiles of temperature, relative humidity, PM10 and PM2.5 in Warsaw and Cracow cities. The national air quality forecast calculated with the GEM-AQ model was evaluated. In addition, the model's capability to reproduce temperature inversion will be examined.We will present and discuss the results of the measurement campaigns, and the comparison with the model results, in different meteorological and air quality conditions. 
Hydrometeorological raster datasets (HYRAS) - Description and new developments
Authors: Kunert Lisa , Rauthe Monika , Brendel Christoph , Rauthe-Schöch Armin , Deutschländer Thomas
Published: July 2023

In order to be able to analyse the past weather and climate, high-resolution (5 km x 5 km) observational gridded data sets over long periods are required. The HYRAS data sets are based on daily data from meteorological stations in Germany and its river catchment areas for the parameters daily minimum, mean, and maximum temperature, relative humidity, global radiation and precipitation. Hence all for the water sector important parameters are included and the HYRAS grids thus allow many applications in the field of climatology and hydrology as well as in other sectors affected by climate change. The data covers the period from 1951 to 2020, except precipitation, which is on the one hand daily updated for the area of Germany and on the other hand covers the period since 1931 with a horizontal resolution of 1 km x 1 km. The data sets have been developed at Deutscher Wetterdienst (DWD) in two large research programs (KLIWAS and BMDV network of experts) financed by the German Federal Ministry for Digital and Transport. Nowadays, the DAS (Deutsche Anpassungsstrategie) core service “Climate and Water”, which is an operational climate service for climate and water in Germany, is responsible for the operational production of the HYRAS data sets.
 
With the new version of HYRAS (v5.0), the input station data control has been considerably improved. Digitisation and data control made it possible to use more and qualitatively better station data compared to the previous versions. New data sources (precipitation totaliser data in the alpine region) improved the background field used for the interpolation of precipitation. For a broader usability of the dataset, the netCDF attributes have been revised. This allows the data to be read in more easily by common software packages like ArcGIS, QGIS and Panoply. Due to the longer time period covered by the new version, the climatological long-term averages for the most recent climatological period 1991-2020 can now be provided.
We will give an overview of the HYRAS data sets and show a few examples of validation. Furthermore, we will provide some insights into broad applications of these data sets.
Better accounting of droughts in long-range inflows scenarios with TULIP
Authors: Horsley David , Bennett James , Schepen Andrew , Robertson David
Published: July 2023

Many water management agencies rely on stochastic inflow scenarios to plan water operations. For example, Hydro Tasmania, Australia’s largest hydropower generator and water manager, relies on 20+ year inflow scenarios to assess the long-range sustainability of their power generation system. A variety of methods are available for stochastic data generation, but many assume a stationary climate. In locations where inflow has long-term trends, assuming a stationary climate in stochastic data generation is likely to underestimate future wet or dry extremes, in particular for sequences of dry or wet months or years.To address this issue, we have developed the Trend and Uncertainty in Long Inflow Predictions (TULIP) model. TULIP is a Bayesian model that generates long-range predictions of inflows at the monthly time step. TULIP accounts for:Heteroscedasticity and skew in inflow data by using data transformation with the sinh-arcsinh transformation, and zero values with censoring
Spatial correlation between inflow sites
Autocorrelation using a first-order autoregressive model
Linear trend in inflow
Seasonal variation in properties (1)-(4), using Fourier series to control the parameters
TULIP is being implemented operationally by Hydro Tasmania to replace its existing method of generating stochastic scenarios, which assumes a stationary climate. At sites with long-term trends in historical inflow, we show that TULIP produces more reliable long-range predictions than is possible if a stationary climate is assumed. This allows TULIP to produce sharper ensembles and more realistic projections of future drought, allowing Hydro Tasmania to better plan for the long-range sustainability of its system. In this presentation we describe the TULIP model and its performance. We also discuss future plans to incorporate information on inflow trends from global and regional climate models into TULIP.
Air temperature impact on springtime tree phenology in Poland based on satellite data
Authors: Sulikowska Agnieszka , Grabska-Szwagrzyk Ewa , Wypych Agnieszka
Published: July 2023

Air temperature is a crucial driver of many plant developmental processes, among which the initiation of spring activity is the most prominent. Recent climate warming has been found to alter plant phenology in many European regions. However, ultimate conclusions regarding this relationship are still challenging as quantitative estimates are strongly diverging. Moreover, the results concerning the role of temperature extremes, i.e., unusually warm or cold periods, are equivocal. Studying these complex links is of utmost importance as changes in plant phenology affect basic ecosystem functions, including water, carbon, and energy fluxes, as well as plant-animal interactions and ecosystem productivity. Recent progress in research based on satellite phenology indicates that it is a powerful tool to monitor terrestrial vegetation and its responses to climate drivers. It provides qualitatively different traits than ground-based observations, but these two sources of information complement each other well. The use of new generations of satellites with high spatial and temporal resolution helps to gain a better insight into the climate-phenology relations.
The main aim of this study is to assess the effect of air temperature conditions on the start of the spring activity of deciduous trees in Poland during 2018-2023. Data used in the study include the E-OBS (v27.0e) gridded daily mean, maximum and minimum temperatures, and the Sentinel-2 imagery over March-June. The tree species chosen for the analysis are common beech (Fagus sylvatica), silver birch (Betula pendula), and two species of oak (Quercus), which are among the most abundant in Poland. Several hundred single species stands were delimited across the area of Poland to study inter- and intraspecific differences in temperature-phenology relations. General temperature conditions during six individual seasons were assessed using the growing degree days (GDD) for 0°C and 5°C base temperatures. Special attention was paid to extremely warm or cold events, i.e., warm and cold spells, defined using percentile-based thresholds. Their effects were evaluated regarding their intensity and timing within the season. Trees’ response to temperature conditions was assessed using satellite-derived start-of-season (SOS) metric based on derivatives calculated from two indices: MTCI (MERIS Terrestrial Chlorophyll Index) and EVI (Enhanced Vegetation Index).
This preliminary study provided insights into complex links between temperature conditions and spring phenology of deciduous trees, showing that responses to climate drivers, especially extreme events, are species-dependent. Large inter-annual variability in phenology has also been shown – estimated SOS varied between studied seasons by more than 20 days. The results also proved the Sentinel-2 data to be useful in the monitoring of individual tree species phenology.
The lockdown, the earthquake and the moving - the three communication challenges
Authors: Špoler Čanić Kornelija , Grljak Ivana
Published: July 2023

The Croatian Meteorological and Hydrological Service (DHMZ) has faced significant challenges in recent years that have greatly impacted and altered its daily operations, particularly in the part of communication and media. The first major challenge was the global lockdown imposed in March 2020 due to the COVID-19 pandemic. As if that was not enough, the city of Zagreb was struck by a devastating earthquake during the same period, causing severe damage to the DHMZ administration building and making access to infrastructure tools extremely difficult or even temporarily impossible.
Despite the justified fear and disruption caused by the earthquake, DHMZ employees demonstrated a strong sense of responsibility and managed to maintain continuity in their main operational activities. They made efforts to remain accessible to users, media, and the general public through alternative means such as the DHMZ website, social media platforms like Twitter and YouTube channel and email.
As the initial fear of earthquakes subsided and quarantine measures relaxed, DHMZ faced the daunting task of relocating from the damaged building to a rented one that was not originally designed for the specific needs of a national meteorological and hydrological service. Throughout this process, DHMZ had to navigate the challenges of maintaining physical distancing measures while preserving close internal and external communication to ensure that the main operational activities of the service were not disrupted.
This experience has provided DHMZ with valuable lessons in communication during times of crisis. It highlighted the importance of having robust communication channels in place, including alternative methods such as social media and email, to ensure continued availability to users, media, and the general public. It also underscored the significance of maintaining close internal and external communication, even in challenging circumstances, to ensure that the service can fulfil its mission effectively. DHMZ has learned from these challenges and continues to strive for effective communication and media outreach in its daily operations.
This work contains the lessons learned from this period of challenges and highlights the importance of communication strategies, alternative channels, and maintaining internal and external communication during times of crisis.
A national in situ soil moisture measurement network for Switzerland
Authors: Bircher-Adrot Simone , Roulet Yves-Alain , Aellen Jean-Marc , Grandjean Jacques , Widmer Alexandre , Félix Christian , Humphrey Vincent
Published: July 2023

The latest Swiss hydrological scenarios predict more frequent and longer-lasting droughts. The Federal Council has just commissioned the establishment of a national drought monitoring and forecasting system based on an integrative approach using in situ, satellite and modeled data. A key element is the installation of a national near-real time in situ soil moisture network that will transfer existing research networks into a long-term secured operational service with homogenized quality control. Where necessary, new additional sites shall enhance spatial representativity.
In addition to drought monitoring, the collected data should also be suitable for use in numerous other applications. The network shall consist of about 30 grassland and forest stations distributed throughout Switzerland. The grassland stations will be exclusively collocated with existing meteorological stations. A good link to the existing Swiss irrigation network with a large number of soil moisture measurements in cultivated fields will be ensured. 
In order to capture the soil water characteristics curve as well as possible, continuous measurements of both volumetric soil moisture and water potential are planned. In addition, auxiliary soil parameters essential for process understanding and modeling will be collected throughout the soil profiles at each site.
Currently, technical implementation issues are being addressed and the soils from a pre-defined set of potential sites are being pre-sampled by the Swiss Competence Center on Soils in order to assess their quality as national sites. The installation phase is scheduled to begin in spring 2024 at the latest and be completed by the end of 2025.
In this contribution the project and its current status will be detailed.
Towards interactive real-time forecasts of weather-related fire brigade operations
Authors: Becker Nico , Göber Martin , Rust Henning , Ulbrich Uwe
Published: July 2023

Severe weather events like thunderstorms or extra-tropical cyclones can lead to large numbers of fire brigade operations. For example, heavy precipitation can lead to local flooding of basements or underpasses, while wind gusts can lead to treefall and damages to buildings and structures. Such events disrupt the routine operations at fire departments, because a large number of calls need to be handled within a short period of time. However, if suitable warning information about approaching weather events is available in time, there is potential for preparatory actions, for example calling in additional staff or preparing equipment and vehicles. Traditional weather warnings provide information about atmospheric hazards and possibly qualitative statements on expected impacts of the event. However, a quantitative estimate of weather impacts is difficult, because effects of local exposure and vulnerability needs to be taken into account. For example, the extent, intensity and duration of the weather event needs to be combined with information on the numbers and characteristics of affected buildings, trees and infrastructure. Because quantitative impact information is usually not provided in warnings, the estimation of weather impacts on fire brigade operations is left to the experience of emergency managers. Data-based statistical models for for weather-related fire brigade operations could help emergency managers in the decision-making process in an operational setting.
In this study we aim to develop and evaluate models and interactive visualization tools for weather related fire brigade operations in a co-design approach together with fire brigades from different regions of Germany. Fire brigade operations will be modeled based on weather information from nowcast products and ensemble forecasts, as well as exposure information from open data sources like OpenStreetMap. Here, we present methodologies for interactive computation and visualization of probabilistic hazard and impact information using logistic regression models. The aim is to allow for a flexible selection of the spatial and temporal scale of forecast information. This can help emergency managers to plan operations, for example based on specific shift schedules.