bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of different domain configurations on WRF solar irradiance estimation at Badajoz (Spain)
Authors: Escobar Julio A. H. , Sánchez-Hernández Guadalupe , Serrano Antonio , García José Agustín
Published: June 2021

Over the last decades, numerical prediction models, such as the Weather Research and Forecasting (WRF), have emerged as one of the most powerful tools for solar radiation exploitation as renewable energy. A reliable forecast of solar radiation is an effective method to account for its variability and facilitate its integration into the grid. This study analyzes the influence of different domain configurations and spatial resolutions on the WRF solar radiation estimation. To this aim, different domain configurations centered on the city of Badajoz (Spain) have been tested. Thus, three different combinations of two nested domains (D01; higher domain; D02; inner domain) defined on a Lambert Conformal projection have been analyzed. Configurations C1 and C2 use the same domains but differ in the resolution of the nested domain (D02): 9 km for C1 and 3 km for C2. C3 has been defined to perform simulations at a higher resolution, consisting of two nested domains of 9 km for D01 and 1 km for D02. Due to WRF’s requirements on grid ratio between nested domains and computational efficiency criteria, this third configuration uses the same D02 dimensions as C1 and C2, but notably smaller D01 dimensions. All these configurations have employed the same WRF parameterizations. The initial and lateral boundary conditions for the meteorological fields are obtained from the reanalysis ERA5. Finally, the estimated solar radiation for the inner domains at 9, 3 and 1 km has been compared with ground-based solar radiation measurements. The results show a good performance of all the analyzed configurations, with an average relative MABE value of 14.95% and mean relative RMSE of 23.7%. Linear regression analysis between simulated and reference ground measurements have reported a slope of 0.83 for C1, 0.80 for C2 and 0.77 for C3. C3 tends to overestimate the reference measurements, while C1 and C2 tend to underestimate them. This underestimation is more remarkable for C2, likely due to the higher grid ratio in this configuration, 1:9 versus 1:3 in C1. Additionally, the analysis of differences between WRF simulation and reference data with respect to geometrical factors and sky conditions have reported differences between configurations. All these results reveal that different aspects related to the domain configuration, and not only final resolution, can influence the solar radiation forecasting and point out the need to find the most suitable configuration for each specific problem. Acknowledgments. This work is partially funded by FEDER/Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación of Spain through project RTI 2018-097332-B-C22, and by Junta de Extremadura-FEDER through project GR18097.
Towards operational assimilation of surface based remote sensing temperature and humidity profiler data at MeteoSwiss
Authors: Crezee Bas , Merker Claire , Vural Jasmin , Leuenberger Daniel , Haefele Alexander , Hervo Maxime , Martucci Giovanni , Arpagaus Marco
Published: June 2021

The current atmospheric observing systems fail to provide observations of temperature and humidity in the planetary boundary layer (PBL) with satisfactory spatial and temporal resolutions despite their potential positive impact on numerical weather prediction (NWP). This is particularly critical for humidity, which exhibits a very high variability in space and time, and for the vertical profile of temperature, which determines the atmospheric stability. Therefore, the analyzed thermodynamic structure of the PBL can be prone to errors, leading to poor forecasts of warnings for relevant phenomena, such as severe storms due to intense summer convection or winter fog and low stratus.

One approach to improve the model’s representation of the PBL is to include novel, ground-based remote sensing profiler observations in the data assimilation system to improve the forecast initial conditions. This also improves the quality of downstream applications relying on a good representation of the PBL in the model, such as dispersion modelling for emergency response after nuclear, chemical or biological incidents.

In this contribution, we present results of the MeteoSwiss effort to include observations from Raman lidar and microwave radiometers into the 1km mesh-size ensemble data assimilation system KENDA-1. To this end, we have developed a forward operator for water vapor mixing ratio and temperature to assimilate profiles from the Raman lidar. Brightness temperatures from the microwave radiometers are assimilated using the RTTOV-gb forward operator. We produced extensive O-B statistics to validate the observations with respect to the model and to derive the error covariance matrices of the observations. Furthermore, we will present results of several data assimilation cycling experiments during summer-time convective situations.
Preliminary results of the Analysis of Precipitation Processes in the Eastern Ebro Subbasin (WISE-PreP) Field Campaign within HILIAISE
Authors: Bech Joan , Udina Mireia , Codina Bernat , Gonzalez Sergi , Garcia Albert , Altube Patricia , Mercader Jordi , Callado Alfons , Arús Joan , Rodríguez Oriol , Casellas Enric , Roura-Adserias Francesc , Rosell Àngela , Polls Francesc , Peinó Eric , Kosovic Branko , Montornès Àlex , Escribà Pau , Trapero Laura , Paci Alexandre ,   more authors
Published: June 2021

Understanding future changes of the terrestrial water cycle and their interaction with human activity, with emphasis on agricultural areas, was selected as one of the World Climate Research Programme (WCRP) Grand Challenges, entitled “Water for the Food Baskets of the World”. Within this framework, the scientific objectives of the “Human Imprint on Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment” (HILIAISE) are the characterization of evapotranspiration and other key processes of water cycle in semi-arid environments. For this purpose, an international field campaign, scheduled for 2021, has been planned focused on a region with highly contrast surface characteristics (irrigated vs non-irrigated areas), particularly during summer.

An overview and preliminary results of a specific project (WISE-PreP) within HILIAISE is given here. WISE-PreP was designed to study precipitation processes aiming to characterize possible differences in precipitation induced by surface characteristics. For this purpose, planned instrumentation for the campaign includes the deployment of three sites equipped each with a vertical radar Doppler Micro Rain Radar (MRR) and a laser disdrometer (PARSIVEL), covering both irrigated and non-irrigated sites, with three disdrometers (model PARSIVEL-2) and three MRRs (one model MRR-2 and two MRR-PROs). Time series of vertical precipitation profiles will be recorded to study microphysical processes trough the evolution of raindrop size distributions and related variables including precipitation intensity or convective vs stratiform rainfall regimes. Additional observations include raingauge data, C-band Doppler weather radar observations, and satellite products, as well as high resolution deterministic numerical weather prediction model data plus Ensemble Prediction Systems (EPS) model output. Funding for this research was provided by “Analysis of Precipitation Processes in the Eastern Ebro Subbasin” (WISE-PreP, RTI2018-098693-B-C32) and the Water Research Institute (IdRA) of the University of Barcelona.
Evaluation of Radiative Transfer Model Calculations of Solar Actinic Flux Densities with HALO Aircraft Measurements
Authors: Kremer Arthur , Bohn Birger
Published: June 2021

Solar actinic radiation is driving atmospheric photochemistry. Consequently, chemistry-transport models rely on accurate model predictions of actinic flux densities to correctly reproduce the essential impact of photolysis processes. Cloud effects are most challenging in this context because of their potentially large influence and their variability. In this study, the effects of clouds, aerosols and ground albedos on solar actinic radiation are investigated using 1D satellite-aided radiative transfer calculations and in-situ aircraft measurements.

Spectral actinic flux densities in the range 280-650 nm are calculated with the latest version of the libRadtran model utilizing cloud products from geostationary satellites (NASA SatCORPS) as well as aerosol properties (MODIS, MOD08_D3), surface albedos (MODIS, MCD43A3) and total assimilated ozone columns (TEMIS, MSR-2) from polar orbiting satellites as key input parameters. The evaluation of the performance of the model output is made by comparison with data from several campaigns with the research aircraft HALO (High Altitude and Long Range Research Aircraft) where spectral actinic flux densities were measured during a total of around 90 research flights.

As a prerequisite to study cloud influence, clear-sky cases were investigated in detail to quantify the impact of the aerosol optical thickness and surface albedo on spectral actinic flux densities. Over land, radiative transfer calculations show good agreement with the measured data independent of wavelength and altitude within about 10% under clear sky conditions. Over the ocean the situation is complicated, because ocean surface albedos (OSA) are not available from satellite observations. Available OSA parametrizations, that depend on atmospheric conditions, tend to lead to a slight overestimation of upward-directed actinic flux densities in particular in the visible range, but the agreement for total actinic flux densities is still comparable with that over land. With sufficient agreement of modelled and observed actinic flux densities under clear sky conditions, flight paths with clouds will be included comprising above-cloud, in-cloud and below-cloud conditions. In the model, liquid cloud effects can be parametrized using Mie theory, but ice clouds pose a more complex problem, due to the wide range of possible structures of ice crystals. Finally, the intent of this study is to asses the quality of the radiative transfer modelled actinic flux densities based upon the satellite-derived cloud information.
Retieving antenna miss-pointing for vertical pointing cloud radar and correcting the introduced Doppler velocity errors in the measurements
Authors: Pfitzenmaier Lukas , Kollias Pavlos , Löhnert Ulrich
Published: June 2021

In the last decades, Doppler velocity measurements from zenith pointing radars have evolved to a standard radar variable. Measuring Doppler velocities allow estimating particle sedimentation or fall velocity of hydrometeors and thus offer key information to evaluate micro-physical parametrizations in numerical weather prediction models. In the future, the joint ESA-JAXA satellite mission EarthCARE features the first Doppler capable 94-GHz Cloud Profiling Radar (CPR), with enhanced sensitivity and improved resolution compared to the CloudSat CPR. These features, especially the Doppler velocity measurements, are expected to improve the CPR-based microphysical retrievals in clouds and precipitation and for the first time provide information about convective motion in clouds.

To evaluate EarthCare CPR Doppler velocity from the ground, the Doppler velocity from five ground-based zenith pointing 94 GHz radar spread over Europa should be used in future. To increase the quality of the measured Doppler velocity the antenna miss-pointing has to be estimated. Unknown antenna miss-pointing is the main source of error in Doppler velocity measurements and can reach values on the same order as the fall velocity of pristine ice crystals. Knowing the angle of miss-pointing, the error in the measured Doppler velocity measurements can be corrected and the precision and quality improved. This is especially important for cases where Doppler velocity values are direct input for retrievals, which, e.g., employ multiple radar sensors with matching sampling(?) volumes.

Within this work we will present a retrieval technique to identify the angle of antenna miss-pointing for ground-based radar profilers and correct the measured Doppler velocity values. The retrieval technique is a statistical method requiring the uncorrected Doppler velocity measurements and additional wind information from reanalysis or in parallel measuring sensors. Evaluation of the retrieval was done using different wind input data sets, e.g., ECMWF IFS wind fields or retrieved wind information from Radar scans. Also, the retrieval was used to correct the miss-pointing angles of two in parallel measuring zenith pointing radars and, therefore, correct the velocity errors in dual Doppler velocity field.  
Guidance to Measuring, Modelling and Monitoring the Canopy Layer Urban Heat Island
Authors: Schluenzen K. Heinke , Grimmond Sue , Baklanov Alexander
Published: June 2021

Today, every second person lives in a city, and urbanization is continuously increasing. For 2050, it is to be expected that 2 out of 3 people will live in a city and thus the vast majority of the world's population will be affected not only by global climate change but also by locally induced climatic changes. The canopy layer urban heat island (CL-UHI) is one of the most well-known meteorological characteristics of urban areas found in cities small and large around the world. Its characteristics differ between cities, across a city and with time. The climate change induced warming cities experience is additionally impacted by the CL-UHI.

Despite the city-scale importance of CL-UHI, the WMO has not had any specific guidance on this. In response to the request of the 18th World Meteorological Congress (Resolutions 32 and 61) experts from WMO GAW (Global Atmosphere Watch) Urban Research Meteorology and Environment (GURME) initiated in 2020 preparation of a guidance on measuring, modelling and monitoring the CL-UHI. The guidance is a community-based development with 30 contributors providing expertise in all different aspects of CL-UHI. This includes a clear definition of what a CL-UHI is and clarifications of what it is not, how it develops (e.g. meteorological and morphological influences), methods to assess CL-UHI intensities (measurements,  modelling approaches) as well as when its assessment  (applications) is needed and how it can be reduced (or when it is beneficial).

The presentation will specifically focus on the key questions addressed in the guidance: what a CL-UHI is and what it is not, where CL-UHI values are relevant for and the many challenges that exist in simulating the CL-UHI with different models.
From a science vision to a new probabilistic post processing system at the Met Office
Authors: Roberts Nigel ,   co-authors who have worked on this project
Published: June 2021

A fully probabilistic post processing system called IMPROVER has been developed at the UK Met Office. IMPROVER provides frequently updated probabilistic gridded forecasts, as well as forecasts for point locations, for input into automated forecast generation and for users such as operational meteorologists. Although the outputs are probabilistic, a deterministic interpretation can be extracted if required.

The scientific rationale behind this endeavor is the need to make more optimal use of the current and future generations of convection-allowing Numerical Weather Prediction (NWP) models and ensembles. The aim is to provide seamless, calibrated, probabilistic forecasts that are a blend of NWP models/ensembles from nowcasting to medium range. Today’s NWP systems offer not only many ensemble members but also frequent updates making it very difficult for users to manage the data and exploit latest information, so a key capability of IMPROVER is the frequent cycling, providing a continuously updated forecast blending the most recent available data.

Several key scientific benefits arise from the probabilistic approach on top of the capability to provide probabilistic outputs. Probabilities allow much simpler and effective blending with older forecasts or between different models/ensembles. We have introduced a variety of probabilistic neighbourhood methods to account for the inherent limited predictability at small scales. Some of these can incorporate topographic variation which is particularly important for variables such as rain, sleet and snow or fog. The ensemble-probabilistic approach has also enabled the use of ensemble calibration methods, which can not only improve skill and spread, but create a much more seamless transition between models/ensembles at different resolutions.

The system is built with a modular software framework that allows flexibility for future development and includes verification at every stage of the processing. IMPROVER is now routinely running with operational support and is expected to become fully operational in 2022. This presentation will briefly describe the initial scientific vision and current IMPROVER capability and discuss where any compromise or re-evaluation had to be made along the way. Finally, thoughts about the future and lessons learnt will be shared.
How is uncertainty represented best to reduce complexity or cognitive cost in high-impact events.
Authors: Guillemot Fabrice
Published: June 2021

Within the forecasters community, it is a common approach to make use of meteorological « conceptual models » to synthetise weather situation key processes. These "models" come along with general physical rules that can help, to understand options, particularly in a high-impact situation with low predictability. At the beginning, it helps to build an appropriate scenario in the decision-process.

Forecasting uncertainty is most of the time considered through a "multi-model" approach, taking into account synoptic and convective scale model outputs, to hightlight the main patterns of uncertainty sources. This subset of model solutions is often called « poor-man-ensemble ». Ensembles provide plenty of relevant information : not only classical probabilities, quantiles, meteograms, but also more subjective visualisations like post-stamps or spaghetti, easy to interpret for forecasters. In the end, all of these informations are mixed to produce or to design mentally the most likely scenario.

Forecasters experience includes a kind of a subjective pseudo climatology, where each one can find references, making use of analogs to understand the meteorological context, the behaviour of the numerical systems in terms of systematic errors, but also to overcome the consequences linked with vulnerability, or to learn from the reaction of our different end-users facing uncertainty. Especially with civil protection, forecasters get trained to develop practical strategies in strong uncertainty contexts.

Within an operational forecasting team, real-time decisions can be affected by high stress levels, as well as collective or individual cognitive biases in uncertainty interpretation. We give here some illustrations from past high impact forecasting situations.
AEMET-γSREPS, a fully operational system for high-resolution probabilistic forecasting over Iberian Pensinsula
Authors: Callado Alfons , Escribà Pau , Quintero David , Gil David , Cortès Maria , Montolio Joan
Published: June 2021

Thinking in terms of uncertainty in the operational forecast is the current goal for high resolution operational predictions. Fields like precipitation with convection, surface winds or fog, are very sensitive to model uncertainties and errors, resulting in a rapid loss of predictability in such meso-scales. The best tool that can quantify this uncertainty is a Short Range Ensemble Prediction System (SREPS). Since final 2016 AEMET runs operationally such a system and names it AEMET-γSREPS. It runs currently at 00 and 12UTC time in three domains over the Iberian Peninsula, Canary Islands and the Antarctic Peninsula, up to 48/60 at 00UTC. According to our operational forecasters, the main contribution of the system is to predict strong convective precipitation and its spatial variability. Besides it is useful to see the range of change of temperature from day to day or the localization of wind gusts in orographic areas and its associated spatial variability. The combination of HARMONIE-AROME with IFS deterministic models and AEMET-γSREPS is the best tool AEMET has for the short-range forecasting. In this talk we first briefly present the design of the system and the domains and times where and when the probabilistic predictions are computed. Then we describe the current status and last updates and the latest verification results. Special emphasis is focused on introducing data assimilation in the system. Finally, the future developments are shown. Although AEMET-γSREPS is developed by the AEMET Predictability group, it wouldn’t exist without the collaboration of the international partners ECMWF, MF, NCEP, NCAR, JMA, CMC and specially the HARMONIE community.
Copernicus European regional reanalysis
Authors: Schimanke Semjon , Isaksson Ludvig , Edvinsson Lisette , Ridal Martin , Berggren Lars , Hopsch Susanna , El-Said Adam , Glinton Michael , Bazile Eric , Le Moigne Patrick , Verrelle Antoine , Dahlgren Per , Randriamampianina Roger
Published: June 2021

The Copernicus European regional reanalysis (https://climate.copernicus.eu/regional-reanalysis-europe) is produced as part of the Copernicus Climate Change Service (C3S). The presentation will introduce the service and its main objectives as well as it will give and overview of available data. Data quality will be demonstrated by comparison with ERA5 and other gridded datasets.

In the first phase of the service, systems inherited from the FP7 project UERRA (Uncertainties in Ensembles of Regional ReAnalyses, http://www.uerra.eu) were applied extending the UERRA-HARMONIE as well as the MESCAN-SURFEX datasets. These datasets contain analyses of the atmosphere, the surface and the soil. UERRA-HARMONIE is a full model system including a 3D-Var data assimilation scheme for upper air observations and an OI-scheme for surface observations. MESCAN-SURFEX is a complementary 2D surface analysis system interfaced to a land surface model. Data is available for entire Europe at a horizontal resolution of 11 km for UERRA-HARMONIE and at 5.5 km for MESCAN-SURFEX. The systems provide four analyses per day – at 0 UTC, 6 UTC, 12 UTC, and 18 UTC. Between the analyses ranges, forecasts of the systems are available with hourly resolution. More than fifty parameters are available on various level types. Data are available for the period 1961 – July 2019 through Copernicus Climate Data Store (CDS).

In spring 2020, the service started the production of the next generation regional reanalysis. The successor comprises three components:
- CERRA (5.5 km horizontal resolution)
- CERRA-EDA (10-member ensemble at 11 km resolution)
- CERRA-Land (5.5 km horizontal resolution)

In addition to the higher resolution, CERRA is more sophisticated than UERRA. For instance, more observations are assimilated into CERRA, in particular remote sensing data. CERRA is produced with 3-hourly cycling and a flow depending part of the B-matrix is derived from CERRA-EDA. The production of CERRA, CERRA-EDA and CERRA-Land will complete in September/October 2021 and data will become available in the CDS shortly thereafter.

The quality of the regional reanalysis in comparison to ERA5 will be shown with results of the standard HARMONIE-verification package as well as based on certain case studies. For instance, the winter storm Gudrun (January 2005, southern Sweden) will be investigated.
Parameterizing the impact of vegetated urban canopies on wind and temperature fields by using a simple nudging method
Authors: Cheng Ge , Grawe David , Schlünzen K. Heinke
Published: June 2021

Nudging is a simple method that aims to dynamically adjust the model toward the observations by including an additional feedback term in the model governing equation. This method is widely applied in data assimilation due to its simple implementation and reasonable model results. The basic concept of nudging is similar to that of urban canopy parameterization, in which additional terms are usually added in the conservation equations of momentum and energy aiming to simulate the canopy effects. However, few studies have investigated the implementation of nudging methods in urban canopy parameterizations. In this study we developed a multi-layer urban canopy parameterization (UCP) by using a nudging approach to represent the impacts of vegetated urban canopies on temperatures and winds in mesoscale models.

The difficulty of developing UCP by using a nudging method lies in defining appropriate values for the nudging coefficients and the forcing fields (e.g. indoor temperature fields for temperature nudging). To determine nudging coefficients, we use three major urban canopy morphological parameters: building height, frontal area density and building density. The ranges of these parameters are taken from the values for the Local Climate Zones datasets, in our case for the city of Hamburg. The UCP is employed in the three -dimensional atmospheric mesoscale model METRAS. Results show that this UCP can well simulate wind-blocking effects induced from obstacles as buildings and trees and urban heat island phenomenon for cities. Thus, nudging is an efficient and effective method that can be used for urban canopy parameterizations. However, as well known for nudging, it is not conserving energy. Therefore, we investigated the energy loss by tracking the reduced kinetic energy and internal energy. The UCP and model results will be presented.
Project RESCCCUE: “REminding Slovenian authorities Climate Change Crisis requires Urgent Effort”
Authors: Zaplotnik Žiga , Boljka Lina , Črnivec Nina , Slameršak Aljoša
Published: June 2021

The project RESCCCUE aims at addressing the climate change action in Slovenia. We started the project in the autumn of 2019 when we have brought together over 100 leading Slovenian scientists, comprising meteorologists, climatologists, oceanographers, physicists, biologists, chemists, geographers, and others. Together we wrote an open letter to the Slovenian government: “A request of Slovenian researchers to take immediate action on improving the climate change mitigation and adaptation policy”. The open letter received extensive media coverage, as well as provoked a reaction from the political authorities and served as a kick-off for various subsequent climate change communication activities. We therefore continued with multiple media outreach and communication events, both jointly as a team and individually. This included appearances on the radio and television, interviews for newspapers and magazines, social media platforms, and popular scientific talks. We have thereby demonstrated that values such as a team spirit, mutual help and collaboration are crucial for far-reaching actions. All in all, the project strives to advance climate literacy and science-based policy making in Slovenia. Additionally, we also promote research in meteorology and climatology to the Slovenian youth (public talks for schools, summer schools, seminars). Although the project has already proved successful in igniting nationwide debate on  climate mitigation, RESCCCUE is a continuing, ongoing project. We are currently establishing an online platform called “Podnebnik” that will track climate action in Slovenia and allow an exchange of science-based views on climate change mitigation and adaptation. To do this, we have established connections with data scientists behind the very successful Slovenian Covid-19 tracker “Sledilnik” (sledilnik.org), and many other Slovenian agencies from the relevant fields, as well as other Slovenian scientists from across the globe. We firmly believe that this platform will help decision makers and the general public to understand the diversity of the climate change challenge and take meaningful climate action. Throughout the project we have developed valuable skills and experience in scientific communication. We hope that our project will inspire more scientists to engage in communication of climate change science and in debates on societal impacts of climate change.
Predictions of the boreal winter stratosphere with the C3S multi-model seasonal forecast system
Authors: Portal Alice , Ruggieri Paolo , Palmeiro Froila M. , Garcı́a-Serrano Javier , Domeisen Daniela I. V. , Gualdi Silvio
Published: June 2021

As a result of the recent progress in the performance of seasonal prediction systems, forecasts of the mid-latitude weather at seasonal time scales are becoming increasingly important for societal decision making, as in risk estimate and management of meteorological extreme events. The predictability of the Northern-Hemisphere winter troposphere, especially in the Euro-Atlantic region, stems from the representation of a number of sources of predictability, notably El Nino Southern Oscillation, the stratospheric polar vortex, Arctic sea-ice extent, Eurasian snow cover. Among these, the stratospheric polar vortex is known to play a paramount role in seasonal forecasts of the winter tropospheric flow.

Here, we investigate the performance in the stratosphere of five seasonal prediction systems taking part in the Copernicus Climate Change Service (C3S), with a focus on the seasonal forecast skill and variability, and on the assessment of stratospheric processes. We show that dynamical forecasts of the stratosphere initialised at the beginning of November are considerably more skilful than empirical forecasts based on observed October or November anomalies. Advances in the representation of stratospheric seasonal variability and extremes, i.e. sudden stratospheric warming frequency, are identified with respect to previous generations of climate models running roughly a decade ago. Such results display, however, a large model dependence. Finally, we stress the importance of the relation between the stratospheric wave activity and the stratospheric polar vortex (i.e. the wave—mean-flow interaction), applied both to the variability and to the predictability of the stratospheric mean flow. Indeed, forecasts of the winter stratospheric polar vortex are closely connected to the prediction of November-to-February stratospheric wave activity, in particular in the Eurasian sector.
Measuring Atmospheric Dynamics at a Site with Natural CO₂ Emissions with an Autarkic Wireless Sensor Network
Authors: Büchau Yann , van Kesteren Bram , Platis Andreas , Leven Carsten , Bange Jens
Published: June 2021

The Starzach site in the upper Neckar valley, Germany, is known for its natural degassing of carbon dioxide (CO₂). During the last century, the gas has been mined industrially until yields stagnated and the extraction wells were sealed. Interestingly, CO₂ exhalation spots have reappeared across the site over the last years. Neither the total emission rate across the site, nor the diurnal or seasonal variations of the CO₂ degassing on the site have been quantified scientifically yet.

In this project, an autarkic wireless sensor network is developed to monitor the CO₂ concentrations in the Neckar valley continuously and investigate the spatial and temporal variability. In the project's second phase, gas transport simulations with a numerical dispersion model will be used to assess the actual CO₂ emissions into the lower atmosphere. Ultimately, the developed methods may be exported to other regions with similar gas emission phenomena.

To account for the spatial heterogeneity of the CO₂ outgassing, a dense sensor network is needed. Deploying several dozen stations requires each station to be of reasonable cost. Currently, commercially available, deployable and self-sustaining measurement systems for CO₂ are very expensive. So to facilitate a targeted network with a 10-meter scale mesh size, we developed an infrastructure that meets our requirements. The network’s modular setup permits flexible sensor extension or spatial expansion. A Campbell Scientific IRGASON eddy-covariance station supplements the network as a punctual high-precision reference. Live gathered data are offered to the science community via the publicly accessible OpenSenseMap.org measurement data platform.

In this talk, the sensor network infrastructure is introduced and the low-cost CO₂ sensor performance is assessed. First long-term measurements at the site reveal a clear diurnal cycle of meteorological parameters and especially for the atmospheric CO₂ concentration and stratification. The site's valley location with surrounding hills is shown to create complex flow dynamics.
Co-Evaluation of Climate Services. An analysis of the CLARA experience 
Authors: Delpiazzo Elisa , Bosello Francesco
Published: June 2021

This presentation aims to discuss some issues regarding the role of the economic evaluation of climate services in the context of the Horizon 2020 CLARA project. CLARA provides 14 innovative services based on a co-development approach involving service producers and specific final users. In this context, the first issue is the role of the evaluation in the co-development framework. Our understanding suggests that it cannot be one of the last steps in the process, but a preliminary evaluation should be presented in the co-design of the service. For this reason, we advise the use of the “maximum potential value” as a signal for both developers and users. It derives from a comparison between the values of two alternative knowledge sources (i.e. one other than the climate service and the other as a 100% skill climate service). The “maximum potential value” provides a benchmark against which to compare the final product. It gives insights to the producer how to improve the service, while the final user has a direct and understandable measure of likely benefits from climate service adoption. This directly supports a higher engagement of the final user, whose participation is essential in developing the service as well as in gathering information for the evaluation.

Moreover, the final user’s participation has a strong impact in assessing how the services enter the decision- making process that is sometimes an obscure issue in the internal dynamic of the organizations. Recognizing a benefit stimulate the discussion on how the tool may be used internally. This sometimes leads to changes in the service design to meet better the users’ requirements. Another critical issue is the final user’s ability to translate into actions the signals of the climate services as well as to predict and quantify costs and benefits of actions based on climate services forecasts.

All these issues are discussed presenting examples from the CLARA project, especially from a set of services related to renewable energy production and water management.
The influence of appropriate business models on the realizable value of climate services
Authors: Perrels Adriaan
Published: June 2021

The provision of climate services (and for that matter many similar services informing about the current and expected state of the ambient environment of a user) is sensitive to obstacles to value appropriation both the supplier and the user side. The problem at the upstream side is often related to the appropriate levels of compensation for basic data input. The problem at the downstream side is that the uncertainty of the benefit generation potential for the end-user may prohibit price levels that would be necessary to recover service costs.

As for example illustrated in Larosa and Mysiak (2019) certain combinations of service characteristics and market conditions tend to associate with preferences for certain business models. Yet, the choice for these models is by no means always the outcome of a careful selection process, and even if it is, outcomes may be disappointing. Furthermore, in the background affect policy choices regarding, inter alia, market delineation and innovation policies (Stegmaier and Perrels 2019).

The contribution is a theoretical exercise with stylized information market model demonstrating for a set of varying boundary conditions regarding pricing, data access, market access, public support, and quality control what is the likelihood of viability of a certain service design, and what is the influence of different types of competition (e.g. from abroad).

References:

Larosa, F., Mysiak, J. (2019). Business models for climate services: an analysis. Climate Services, Vol. 17, https://doi.org/10.1016/j.cliser.2019.100111.

Stegmaier, P., Perrels, A., (2019). Policy implications and recommendations on promising business, resourcing, and innovation for climate services, EU-MACS Deliverable 5.2, http://eu-macs.eu/outputs/
The  regional reanalysis COSMO-REA6 and its transdisciplinary applications
Authors: Hense Andreas ,   The Bonn/Cologne group of Hans Ertel Center for Weather Research
Published: June 2021

In recent years, the reanalysis efforts have been focused on increasing the spatio-temporal resolution to better capture the variability of the atmospheric state between the mesoβ up to synoptic scales. An approach to gain a substantial increase in horizontal resolution are regional reanalyses which utilize a limited area model instead of a global one and thus focus on a specific region of the world. For the European continent several regional reanalyses are now available, e.g., HARMONIE (11km) or COSMO-REA6 (6km).

This work presents ongoing work of a variety of applications and evaluations made possible through the hourly 6km data of the COSMO-REA6 reanalysis product. 
Snow and precipitation analysis and events are going to represent better the smaller scales. Here we will show the representation of the scaling properties of the precipitation extremes and an evaluation of the 2005 extreme early winter snow event which happened in Western Germany.  With this reanalysis we also investigated the potential of season identification, finding that gridpoint-wise vertical temperature and wind information provides efficient ways to classify probabilistically a single day into a specific season.  Moreover, the calculation of the bio-climatic variables from COSMO-REA6 allowed the comparison with the Worldclim 2.0 dataset. The main advantage of the newly derived bio-climatic variables is the internal consistency between the temperature and precipitation-related variables. Furthermore, from the increment analysis, we investigate the soil moisture biases and how they relate to the missing representation of irrigation processes in the COSMO model. Results show that there is a similarity in the specific humidity increments and both the irrigation annual cycle and spatial distribution of irrigated areas. With physically consistent spatio-temporal fields it is possible to investigate human discomfort measurements and their relation to temperature indexes. Lastly, extended use of the COSMO-REA6 data was made for renewable energy applications both for wind turbines and photovoltaic cells. The examples given in this presentation will highlight the general potential of high-resolution reanalyses to be part of transdisciplinary problems related to climate and weather variability.  
Interaction between atmospheric model resolution and energy system model topology
Authors: Zech Matthias , Raventós Oriol , Lünsdorf Ontje , von Bremen Lueder
Published: June 2021

With the increasing penetration of renewable energy capacities in the European energy system, the electricity generators have shifted from centralized power plants to decentralized, weather-dependent wind turbines and photovoltaic systems. Energy system models now rely on skillful weather data to estimate renewable energy feedins on electricity bus levels. These feedins are usually calculated by bilinearly interpolating the closest atmospheric model grid points to the electricity network bus locations. This comes to the cost of averaging multiple atmospheric model grid points reducing overall atmospheric model variability. In addition, electricity grids are often modeled in clustered representations in terms of number of lines and buses. The number of buses is usually much smaller than the number of atmospheric model grid points and therefore some grid points and their characteristics may not be taken into account in highly clustered networks. So far, this interconnection between atmospheric model resolution and electricity grid topology has not been widely investigated.

This study approaches the question if and to what extent the atmospheric model resolution affects the energy system model results. The regional reanalysis COSMO-REA6 is used as a reference data and its resolution is artificially reduced. This allows to compare the loss of information (mainly variability) due to a lower grid point resolution. The weather data is then used within different energy system network topologies to determine the corresponding renewable energy feedins at bus levels. A subsequent optimal power flow model estimates the impact on energy system metrics as storage usage and economic dispatch costs to further understand the relationship between atmospheric model resolution and energy system model topology. This study provides useful insights to choose the appropriate resolution of the atmospheric model input given an energy system model. 
CORDEX FPS on Urbanization - URBan environments and Regional Climate Change (URB-RCC)
Authors: Halenka Tomas , Langendijk Gaby
Published: June 2021

Cities play a fundamental role on climate at local to regional scales through modification of heat and moisture fluxes, as well as affecting local atmospheric chemistry and composition, alongside air-pollution dispersion. Vice versa, regional climate change impacts urban areas and is expected to increasingly affect cities and their citizens in the upcoming decades. Simultaneously, the share of the population living in urban areas is growing, and is projected to reach about 70% of the world population up to 2050. This is especially critical in connection to extreme events, for instance heat waves with extremely high temperatures exacerbated by the urban heat island effect, in particular during night-time, with significant consequences for human health.

Cities are becoming one of the most vulnerable environments under climate change. In 2013, the CORDEX community identified cities to be one of the prime scientific challenges. Therefore, we proposed this topic to become an activity at CORDEX platform, within the framework of so called flagship pilot studies, which was accepted and the FPS URB-RCC activity has been started in May this year.

Indeed, from the perspective of recent regional climate model developments with increasing resolution down to the city scale, proper parameterization of urban processes is starting to play an important role to understand local/regional climate change. The inclusion of the individual urban processes affecting energy balance and transport (i.e. heat, humidity, momentum fluxes) via special urban land-use parameterization of distinct local processes becomes vital to simulate the urban effects properly. This will enable improved assessment of climate change impacts in the cities and inform adaptation and/or mitigation options by urban decision-makers, as well as adequately prepare for climate related risks (e.g. heat waves, smog conditions etc.).

The main goal of this FPS is to understand the effect of urban areas on the regional climate, as well as the impact of regional climate change on cities, with the help of coordinated experiments with urbanized RCMs. While the urban climate with all the complex processes has been studied for decades, there is a significant gap to incorporate this knowledge into RCMs. This FPS aims to bridge this gap, leading the way to include urban parameterization schemes as a standard component in RCM simulations, especially at  high resolutions.
Multi-annual variability of summertime atmospheric and surface urban heat island in Kraków, Poland
Authors: Hajto Monika J. , Bokwa Anita
Published: June 2021

The urban heat island (UHI) effect is primarily related to the atmosphere, but may also refer to the surfaces. The atmospheric UHI (AUHI), determined using air temperature (Tair), and the surface UHI (SUHI), assessed using land surface temperature (LST), are distinguished. There is undoubtedly a relationship between SUHI and AUHI due to the modulation of Tair by LST. On hot days in the summer months, the SUHI/AUHI effect may increase the heat load, which is dangerous to the health and comfort of people staying in the city. Detailed characteristics of the spatial distribution of Tair and LST in urban areas are required to identify the parts of the city with the highest heat load. Spatially continuous Tair data, enabling better characterizing AUHI, can be obtained by modelling. Satellite thermal data (LST) can be used as input to the Tair spatial distribution model. Satellite data with 1 km spatial resolution, due to availability several times a day, are most useful in characterizing SUHI diurnal variability and the relationship of LST with Tair. The detailed knowledge of LST and Tair correlation should be helpful in the development of the Tair estimation algorithm based on the LST values. Better recognition of the relationship between LST and Tair, and thus improving the quality of modelling the spatial distribution of Tair in urban area, can possibly be achieved through downscaling of LST data to higher spatial resolution. In the study the method of LST downscaling from 1 km to 100 m was developed, using LST derived from AVHRR, Landsat, ASTER and ECOSTRESS data. The LST-Tair correlation in the diurnal course was examined and the influence of LST downscaling on the correlation was assessed. A Tair regression model was developed based on LST, depending on local climate zone (LCZ). LST and Tair maps for Kraków and its vicinities were prepared, and on the basis of them the intensities of AUHI and SUHI in the multi-year period (2010-2019) in the summer months (June, July, August) were determined, separately for day and night.
Tailoring weather information for specific users
Authors: Hladnik Zakotnik Veronika
Published: June 2021

In June 2018 at Slovenian Environmental Agency (ARSO) the internal project SPOMIN was started. In Slovenia, weather forecasters have only one operational shift per day, which lasts 12 hours, and only one weather forecaster is mostly responsible for general forecasts for the entire country. Dedicated forecasts for special users are fragmented and delegated to teams across the Agency; in most cases there is only one person responsible for each specific topic, and some forecasts for specific activities are not even produced, for example for leisure activities, skiing, surfing, etc. Therefore, the aim of SPOMIN project was to harmonize operational meteorological information and forecasts and collect their production in one team.

For the SPOMIN proposes, we issued a questionnaire addressed to our users and received more than 1000 answers, many of them were descriptive. Many of our users are familiar with our special products for users, but they are missing additional graphic representation or explanatory text or more details related to their activity. There are also some of users who are unaware of our products as they are not easy to find on our websites. Our users know what kind of information and forecasts they are missing, and they provided us with a lot of ideas how to improve our products and which new products should we develop in future. Thus, the project team suggested some new products and upgrade of existing ones. While the project was finished in 2020, the conclusions and results were conveyed to the newly formed team for specific forecasts.

At present, we are not able to enrich the content of our web site with new kinds of information, because the web site is currently under renovation. To overcome this situation, we have started adding more information to the social network where we have over 20,000 followers, recording podcasts with highly relevant topics, producing lots of interesting infographics, and so on. Our plans for the future include production of videos with forecasts and meteorological educational content. Of course, we will upgrade and implement the ideas developed in SPOMIN project and integrate them on our new website which will be much more user oriented as it is the current one.

Selected examples of tailored information for users published on our social media will be presented.

 