ALBERT

Description: Comparison of regional and global reanalysis near-surface winds with station observations over Germany Advances in Science and Research, 12, 187-198, 2015 Author(s): A. K. Kaiser-Weiss, F. Kaspar, V. Heene, M. Borsche, D. G. H. Tan, P. Poli, A. Obregon, and H. Gregow Reanalysis near-surface wind fields from multiple reanalyses are potentially an important information source for wind energy applications. Inter-comparing reanalyses via employing independent observations can help to guide users to useful spatio-temporal scales. Here we compare the statistical properties of wind speeds observed at 210 traditional meteorological stations over Germany with the reanalyses' near-surface fields, confining the analysis to the recent years (2007 to 2010). In this period, the station time series in Germany can be expected to be mostly homogeneous. We compare with a regional reanalysis (COSMO-REA6) and two global reanalyses, ERA-Interim and ERA-20C. We show that for the majority of the stations, the Weibull parameters of the daily mean wind speed frequency distribution match remarkably well with the ones derived from the reanalysis fields. High correlations (larger than 0.9) can be found between stations and reanalysis monthly mean wind speeds all over Germany. Generally, the correlation between the higher resolved COSMO-REA6 wind fields and station observations is highest, for both assimilated and non-assimilated (i.e., independent) observations. As expected from the lower spatial resolution and reduced amount of data assimilated into ERA-20C, the correlation of monthly means decreases somewhat relative to the other reanalyses (in our investigated period of 2007 to 2010). Still, the inter-annual variability connected to the North Atlantic Oscillation (NAO) found in the reanalysis surface wind anomalies is in accordance with the anomalies recorded by the stations. We discuss some typical examples where differences are found, e.g., where the mean wind distributions differ (probably related to either height or model topography differences) and where the correlations break down (because of unresolved local topography) which applies to a minority of stations. We also identified stations with homogeneity problems in the reported station values, demonstrating how reanalyses can be applied to support quality control for the observed station data. Finally, as a demonstration of concept, we discuss how comparing feedback files of the different reanalyses can guide users to useful scales of variability.

Description: The benefits of emergency rescue and reanalysis data in decadal storm damage assessment studies Advances in Science and Research, 12, 97-101, 2015 Author(s): P. Jokinen, A. Vajda, and H. Gregow Studying changes in storm-induced forest damage in Finland has not been possible previously due to the lack of continuous, long series of impact data. We overcome this by combining emergency rescue data from the Finnish rescue services "PRONTO" (2011-) with ERA-Interim reanalysis data of wind gusts and soil temperatures to define exceedance thresholds for potential forest damage days. These thresholds were applied as a proxy for the period 1979–2013 in order to study the spatial and decadal characteristics of forest damage in Finland due to windstorms. The results indicated that the area most impacted by potential forest damage was the south-western part of Finland along the coast, with 1–10 damaging storm cases per year. A decadal examination highlighted a lull period in the number of potential forest damage days during the 1990s compared to the 1980s and 2000s, albeit no trend was evident. The inclusion of emergency rescue data allowed us for the first time to estimate the spatial distribution and decadal variations of potential forest damage days due to windstorms in Finland. The results achieved will encourage further development of thresholds for potential forest damage by including additional data sources and applying them to future climate scenarios.

Description: On the temporal variability of the surface solar radiation by means of spectral representations Marc Bengulescu, Philippe Blanc, and Lucien Wald Adv. Sci. Res., 13, 121-127, doi:10.5194/asr-13-121-2016, 2016 The continuous wavelet (CWT) and the Hilbert–Huang transforms (HHT) are compared for the analysis of the temporal variability on ten years of daily means of the surface solar irradiance. In both cases, the variability exhibits a plateau between scales of two days and three months that has decreasing power with increasing scale, a spectral peak corresponding to the annual cycle, and a low power regime in-between. The HHT is shown to be suitable for inspecting the variability of the measurements.

Description: Wind gust warning verification Cristina Primo Adv. Sci. Res., 13, 113-120, doi:10.5194/asr-13-113-2016, 2016 Warnings have become a standard product in meteorological centres since they help the public prevent major disasters and minimize costs or losses. They happen rarely and add a new temporal dimension, namely the time window of the forecasted event. Thus, specific verification methods are required to verify warnings. This paper analyses the warning verification issues and includes a real life example, the verification of wind gust warnings at the German Meteorological Centre (Deutscher Wetterdienst).

Description: Influence of sea surface roughness length parameterization on Mistral and Tramontane simulations Anika Obermann, Benedikt Edelmann, and Bodo Ahrens Adv. Sci. Res., 13, 107-112, doi:10.5194/asr-13-107-2016, 2016 Simulated surface winds in atmospheric models depend, among others, on the parameterization of the sea surface roughness. Three parameterizations (variation of Charnock parameter) were tested in the western Mediterranean area during Mistral events with the regional climate model COSMO-CLM. While the whole sea level pressure pattern did not change much, a larger Charnock parameter led to lower wind speeds and a rotation of the wind direction.

Description: Improving the climate data management in the meteorological service of Angola: experience from SASSCAL Rafael Posada, Domingos Nascimento, Francisco Osvaldo S. Neto, Jens Riede, and Frank Kaspar Adv. Sci. Res., 13, 97-105, doi:10.5194/asr-13-97-2016, 2016 To respond to the challenges of climate change, Angola, Botswana, Germany, Namibia, South Africa and Zambia have initiated the regional competence centre SASSCAL. As part of the initiative, Deutscher Wetterdienst (DWD) cooperates with the meteorological services of Angola, Botswana and Zambia to improve the management of climate data. First results of the cooperation between DWD and the Angolan Meteorological Services (INAMET) are presented in order to provide hints for comparable activities.

Description: Validation of the new HelioClim-3 version 4 real-time and short-term forecast service using 14 BSRN stations Claire Thomas, Laurent Saboret, Etienne Wey, Philippe Blanc, and Lucien Wald Adv. Sci. Res., 13, 129-136, doi:10.5194/asr-13-129-2016, 2016 HelioClim-3 (version 4) is a satellite-derived solar surface irradiance database available at d-1 until 2015. To fulfill the requirements of numerous users, a new service based on the principle of persistence has been developed; it provides solar data in real time and forecasts until the end of the current day. The service exhibits good performances for 15 min and 1 h ahead forecasts, and degrades as the temporal horizon increases. Several customers have so far purchased this service.

Description: Atmospheric station Křešín u Pacova, Czech Republic – a Central European research infrastructure for studying greenhouse gases, aerosols and air quality Advances in Science and Research, 12, 79-83, 2015 Author(s): A. Dvorská, P. Sedlák, J. Schwarz, M. Fusek, V. Hanuš, P. Vodička, and J. Trusina Long-lasting research infrastructures covering the research areas of atmospheric chemistry, meteorology and climatology are of highest importance. The Atmospheric Station (AS) Křešín u Pacova, central Czech Republic, is focused on monitoring of the occurence and long-range transport of greenhouse gases, atmospheric aerosols, selected gaseous atmospheric pollutants and basic meteorological characteristics. The AS and its 250 m tall tower was built according to the recommendations of the Integrated Carbon Observation System (ICOS) and cooperates with numerous national and international projects and monitoring programmes. First measurements conducted at ground started in 2012, vertical profile measurements were added in 2013. A seasonal variability with slightly higher autumn and winter concentrations of elemental and organic carbon was revealed. The suitability of the doubly left-censored Weibull distribution for modelling and interpretation of elemental carbon concentrations, which are often lower than instrumental quantification limits, was verified. Initial data analysis also suggests that in summer, the tower top at 250 m is frequently above the nocturnal surface inversions, thus being decoupled from local influences.

Description: Lidar uncertainty and beam averaging correction Advances in Science and Research, 12, 85-89, 2015 Author(s): A. Giyanani, W. Bierbooms, and G. van Bussel Remote sensing of the atmospheric variables with the use of Lidar is a relatively new technology field for wind resource assessment in wind energy. A review of the draft version of an international guideline (CD IEC 61400-12-1 Ed.2) used for wind energy purposes is performed and some extra atmospheric variables are taken into account for proper representation of the site. A measurement campaign with two Leosphere vertical scanning WindCube Lidars and metmast measurements is used for comparison of the uncertainty in wind speed measurements using the CD IEC 61400-12-1 Ed.2. The comparison revealed higher but realistic uncertainties. A simple model for Lidar beam averaging correction is demonstrated for understanding deviation in the measurements. It can be further applied for beam averaging uncertainty calculations in flat and complex terrain.

Description: An overview of the phenological observation network and the phenological database of Germany's national meteorological service (Deutscher Wetterdienst) Advances in Science and Research, 11, 93-99, 2014 Author(s): F. Kaspar, K. Zimmermann, and C. Polte-Rudolf First phenological observations have been performed in Germany already in the 18th century. The onset dates of characteristic phases of plant development (phenological phases) are observed and recorded. Today, Germany's national meteorological service (Deutscher Wetterdienst, DWD) maintains a dense phenological observation network and a database with phenological observations. The data are used in many applications, esp. for advisory activities to agriculture or pollen dispersion information.

Description: User awareness concerning feedback data and input observations used in reanalysis systems Advances in Science and Research, 12, 63-67, 2015 Author(s): H. Gregow, P. Poli, H. M. Mäkelä, K. Jylhä, A. K. Kaiser-Weiss, A. Obregon, D. G. H. Tan, S. Kekki, and F. Kaspar A web-based survey to assess the benefits and gaps in reanalyses as part of growing climate services was carried out in 2013–2014. The survey elicited responses from about 2500 users of climate information. One of the eleven survey points specifically addressed the observations used in reanalysis, with a multiple-choice question "Have you used reanalysis input observations and feedback data?". Almost half of the respondents admitted to not knowing what such data were about. Among the others, specific queries asked for these observations to be made available more openly. This paper summarizes the main findings in regard to use of existing reanalyses as well as user awareness and needs in regard to reanalysis feedback data and input observations. In the future, the information obtained via the survey makes it possible to perform various statistically robust analyses addressing different aspects of the use of reanalysis data.

Description: Towards an integrated probabilistic nowcasting system (En-INCA) Advances in Science and Research, 12, 51-55, 2015 Author(s): M. Suklitsch, A. Kann, and B. Bica Ensemble prediction systems are becoming of more and more interest for various applications. Especially ensemble nowcasting systems are increasingly requested by different end users. In this study we introduce such an integrated probabilistic nowcasting system, En-INCA. In a case study we show the added value and increased skill of the new system and demonstrate the improved performance in comparison with a state-of-the-art LAM-EPS.

Description: On the correlation of spatial wind speed and solar irradiance variability above the North Sea Anna Rieke Mehrens and Lueder von Bremen Adv. Sci. Res., 13, 57-61, doi:10.5194/asr-13-57-2016, 2016 Mesoscale wind fluctuations lead to high wind fluctuations. Enhanced mesoscale wind variability emerges during cold air outbreaks and resulting convection. If these fluctuation occurs during cellular convection, the question arises if it is possible to estimate the spatial variability of the wind by the solar irradiance variability? Cellular convection leads to simultaneous high solar and wind variability, but the highest solar or wind variability occurs due to other meteorological phenomena.

Description: How seasonal forecast could help a decision maker: an example of climate service for water resource management Christian Viel, Anne-Lise Beaulant, Jean-Michel Soubeyroux, and Jean-Pierre Céron Adv. Sci. Res., 13, 51-55, doi:10.5194/asr-13-51-2016, 2016 The use of seasonal forecast, combined with an impact model, could have a tangible positive effect on long-term decisions. This paper presents such an example for the management of a dam in France, studied in the framework of the FP7 project EUPORIAS. It details the assessment process, lead in collaboration with the stakeholder, especially the evaluation of the decision itself. It demonstrates that the introduction of relevant climate products could significantly improve existing practice.

Description: Comparison of regional and global reanalysis near-surface winds with station observations over Germany A. K. Kaiser-Weiss, F. Kaspar, V. Heene, M. Borsche, D. G. H. Tan, P. Poli, A. Obregon, and H. Gregow Adv. Sci. Res., 12, 187-198, doi:10.5194/asr-12-187-2015, 2015 Wind speed measured at the German stations correlate well with reanalysis fields. Monthly means from two global reanalyses (ERA-20C, ERA-Interim) and one regional reanalysis (COSMO-REA6) were analysed and correlate well for the majority of the German stations. Thus we conclude that the monthly and seasonal anomalies recorded at these stations can be understood as representative for a spatial area comparable to the resolution of the reanalyses, at least for the recent years.

Description: Spatial patterns of European droughts under a moderate emission scenario J. Spinoni, G. Naumann, and J. Vogt Adv. Sci. Res., 12, 179-186, doi:10.5194/asr-12-179-2015, 2015 This paper investigates meteorological droughts in Europe for the periods 1981-2010, 2041-2070 and 2071-2100 under a moderate emissions scenario. SPI and SPEI are used to analyze drought frequency, duration, severity, and intensity. Results show that southern Europe is likely to be hit by longer, more frequent, severe, and intense droughts in the near future (2041-2070) and even more in the far future (2071-2100), while less severe and fewer drought events are likely to occur in northern Europe.

Description: Urban warming in villages J. Lindén, C.S.B. Grimmond, and J. Esper Adv. Sci. Res., 12, 157-162, doi:10.5194/asr-12-157-2015, 2015 Long term meteorological records from stations associated with villages are generally classified as rural and assumed to have no urban influence. Using temperature sensor networks installed around two such stations, spatial variations of the same order magnitude as the long-term temperature trend from these stations were found. The potential bias in the long term series therefore warrants careful consideration in temperature trend evaluation also in village stations.

Description: Diurnal temperature cycle deduced from extreme daily temperatures and impact over a surface reanalysis system F. Besson, E. Bazile, C. Soci, J.-M. Soubeyroux, G. Ouzeau, and M. Perrin Adv. Sci. Res., 12, 137-140, doi:10.5194/asr-12-137-2015, 2015 Due to the evolution of the observation network, hourly 2m temperature analysis performed by reanalysis systems shows temporal inhomogeneities. In this study, the diurnal temperature cycle has been reconstructed for stations which only record extreme temperatures to produce new “pseudo” hourly temperature observations. Then they are provided to analysis systems; the results have shown that it enables reducing the bias in temperature analysis.

Description: An overview of the use of Twitter in National Weather Services S. Gaztelumendi, M. Martija, O. Principe, and V. Palacio Adv. Sci. Res., 12, 141-145, doi:10.5194/asr-12-141-2015, 2015 Twitter is a service that enables users to post messages ("tweets") of up to 140 characters supporting a variety of communicative practices. In this paper we analyze different aspects related to the use of Twitter in different National Meteorological Services (NMS) worldwide. Firstly, we will review the general position of NMS worldwide regarding the use of Twitter technology. Secondly, we will focus on different practices of some selected meteorological services. Thirdly, we will deal specifically with the Basque Meteorology Agency (Euskalmet) case. Finally some conclusions are presented.

Description: Comparison of HOMER and ACMANT homogenization methods using a central Pyrenees temperature dataset N. Pérez-Zanón, J. Sigró, P. Domonkos, and L. Ashcroft Adv. Sci. Res., 12, 111-119, doi:10.5194/asr-12-111-2015, 2015 The aim of this research is to compare the results of two modern multiple break point homogenization methods, namely ACMANT and HOMER, over a Pyrenees temperature dataset in order to detect differences between their outputs which can affect future studies. Both methods are applied to a dataset of 44 monthly maximum and minimum temperature series placed around central Pyrenees and covering the 1910–2013 period.

Description: Large-eddy simulation of turbulent winds during the Fukushima Daiichi Nuclear Power Plant accident by coupling with a meso-scale meteorological simulation model H. Nakayama, T. Takemi, and H. Nagai Adv. Sci. Res., 12, 127-133, doi:10.5194/asr-12-127-2015, 2015 A significant amount of radioactive material was accidentally discharged into the atmosphere from the Fukushima Dai-ichi Nuclear Power Plant from 12 March 2011, which produced high contaminated areas over a wide region in Japan. In conducting regional-scale atmospheric dispersion simulations, the computer-based nuclear emergency response system WSPEEDI-II developed by Japan Atomic Energy Agency was used. Because this system is driven by a meso-scale meteorological (MM) model, it is difficult to reproduce small-scale wind fluctuations due to the effects of local terrain variability and buildings within a nuclear facility that are not explicitly represented in MM models. In this study, we propose a computational approach to couple an LES-based CFD model with a MM model for detailed simulations of turbulent winds with buoyancy effects under real meteorological conditions using turbulent inflow technique. Compared to the simple measurement data, especially, the 10 min averaged wind directions of the LES differ by more than 30 degrees during some period of time. However, distribution patterns of wind speeds, directions, and potential temperature are similar to the MM data. This implies that our coupling technique has potential performance to provide detailed data on contaminated area in the nuclear accidents.

Description: The FORBIO Climate data set for climate analyses C. Delvaux, M. Journée, and C. Bertrand Adv. Sci. Res., 12, 103-109, doi:10.5194/asr-12-103-2015, 2015 In the framework of the interdisciplinary FORBIO Climate research project, this paper explains how the gridded daily temperature (minimum and maximum) data set was generated from a consistent station network between 1980 and 2013 in Belgium. Data quality control procedures were applied to the station records to ensure that only valid measurements will be involved in the gridding process. The performance of different interpolation methods has been assessed.

Description: Atmospheric station Křešín u Pacova, Czech Republic – a Central European research infrastructure for studying greenhouse gases, aerosols and air quality A. Dvorská, P. Sedlák, J. Schwarz, M. Fusek, V. Hanuš, P. Vodička, and J. Trusina Adv. Sci. Res., 12, 79-83, doi:10.5194/asr-12-79-2015, 2015 First measurements at the Atmospheric Station Křešín u Pacova revealed a seasonal variability of elemental and organic carbon with slightly higher autumn and winter concentrations. A suitable statistical method for the replacement of very low elemental carbon concentrations (i.e. under the instrument quantification limit) was found. In summer, the top of the 250 m tall station tower is frequently above the nocturnal surface inversions, thus being decoupled from local influences.

Description: Investigation of balancing effects in long term renewable energy feed-in with respect to the transmission grid A. Kies, K. Nag, L. von Bremen, E. Lorenz, and D. Heinemann Adv. Sci. Res., 12, 91-95, doi:10.5194/asr-12-91-2015, 2015 A European power system mainly based on renewable sources will have dominant contributions from wind and solar power. However, wind and solar generation facilities have, due to the weather dependent nature of their resources, highly fluctuating feed-in profiles. To overcome the mismatch between power consumption and generation it is important to study and understand the generation patterns and balancing potentials. High temporally and spatially resolved long term weather data was used to simulate the feed-in from wind and photovoltaics for European countries for the years 2003 to 2012. We investigate storage energy and capacity needs in Europe in dependency of the generation mix from wind onshore, wind offshore and photovoltaics and the share of renewables. Furthermore we compute the storage energy and capacity needs for different transmission scenarios. We show that for unlimited transmission storage needs are reduced mostly by high wind offshore shares. We also show that higher shares above 100% of renewables can decrease the required storage capacity to a higher extent than the required storage energy.

Description: The VIADUC project: innovation in climate adaptation through service design L. Corre, P. Dandin, D. L'Hôte, and F. Besson Adv. Sci. Res., 12, 199-205, doi:10.5194/asr-12-199-2015, 2015 The VIADUC project is to evaluate existing French climate services, as well as to imagine future development in support of adaptation. Climate scientists work together with end-users and a service designer. The designer's role is to propose an innovative approach based on the interaction between scientists and citizens. The users' needs for climate information have been assessed. The lessons learned led to actions which are presented in this paper.

Description: The SASSCAL contribution to climate observation, climate data management and data rescue in Southern Africa F. Kaspar, J. Helmschrot, A. Mhanda, M. Butale, W. de Clercq, J. K. Kanyanga, F. O. S. Neto, S. Kruger, M. Castro Matsheka, G. Muche, T. Hillmann, K. Josenhans, R. Posada, J. Riede, M. Seely, C. Ribeiro, P. Kenabatho, R. Vogt, and N. Jürgens Adv. Sci. Res., 12, 171-177, doi:10.5194/asr-12-171-2015, 2015 One task of the “Southern African Science Service Centre for Climate Change and Adaptive Land Management” (www.sasscal.org) is the provision of climate data for Southern Africa. Extension and improvements of observational networks in Angola, Botswana, Namibia, Zambia and South Africa are supported. This effort is complemented by an improvement of climate data management at national weather authorities, capacity building activities and an extension of the data bases with historical climate data.

Description: MATISSE: an ArcGIS tool for monitoring and nowcasting meteorological hazards V. Rillo, A. L. Zollo, and P. Mercogliano Adv. Sci. Res., 12, 163-169, doi:10.5194/asr-12-163-2015, 2015 Adverse meteorological conditions are one of the major causes of accidents in aviation, resulting in substantial human and economic losses. For this reason it is crucial to monitor and early forecast high impact weather events. In this context, CIRA (Italian Aerospace Research Center) has implemented MATISSE (Meteorological AviaTIon Supporting SystEm), an ArcGIS Desktop Plug-in able to detect and forecast meteorological aviation hazards over European airports, using different data sources.

Description: UV and global irradiance measurements and analysis during the Marsaxlokk (Malta) campaign J. Bilbao, R. Román, C. Yousif, D. Mateos, and A. de Miguel Adv. Sci. Res., 12, 147-155, doi:10.5194/asr-12-147-2015, 2015 A solar radiation measurement campaign was performed in the south-eastern village of Marsaxlokk (35º 50' N; 14º 33' E; 10 m a.s.l.), Malta, between 15 May and 15 October 2012. Erythemal solar radiation (UVER), horizontal global and diffuse components were recorded. Aerosols effects on solar irradiances are evaluated using the Aerosol Modification factor (AMF). Results indicate a greater aerosol effect on UVER than on global solar irradiance. Several dust event trajectories are identified.

Description: Ten years water and energy surface balance from the CNR-ISAC micrometeorological station in Salento peninsula (southern Italy) P. Martano, C. Elefante, and F. Grasso Adv. Sci. Res., 12, 121-125, doi:10.5194/asr-12-121-2015, 2015 Data of surface-atmosphere energy and water transfer from a ten years (2003–2013) period of activity of the ISAC-Lecce micrometeorological station ( http://www.basesperimentale.le.isac.cnr.it ) have been analyzed: to the authors' knowledge this is the first decadal data set of surface-atmosphere transfer in Salento peninsula. The surface energy budget shows a tendency to a positive bias possibly due to several reasons that require more investigations. Some suitable indices related to the surface water balance, such as the precipitation intensity, the aridity index and the ground water infiltration fraction have been calculated. Possible trends of these annual averages in the decadal period are considered, also taking into account the statistical uncertainty associated to measurement errors and missing data. The results indicate a significant increasing in the precipitation intensity together with an experimental evidence of increasing of the ground water infiltration in the measurement area, that is in agreement with recent estimations for the whole Salento peninsula. On the other hand, recent studies show that seawater intrusion and salinization of the deep underground aquifer keep increasing in the same period.

Description: Corrigendum to "Lidar uncertainty and beam averaging correction" published in Adv. Sci. Res., 12, 85–89, 2015 A. Giyanani, W. Bierbooms, and G. van Bussel Adv. Sci. Res., 12, 135-135, doi:10.5194/asr-12-135-2015, 2015 No abstract available.

Description: The benefits of emergency rescue and reanalysis data in decadal storm damage assessment studies P. Jokinen, A. Vajda, and H. Gregow Adv. Sci. Res., 12, 97-101, doi:10.5194/asr-12-97-2015, 2015 Emergency rescue data and weather reanalysis data were combined to study the spatial and decadal characteristics of potential forest damage days in Finland due to windstorms. The most prone area for damage days was the south-western part of Finland. Results also indicated a lull period during the 1990s compared to the 1980s and 2000s, albeit no trend was evident. The study highlighted the importance of not only focusing on wind speeds, but also soil conditions.

Description: Lidar uncertainty and beam averaging correction A. Giyanani, W. Bierbooms, and G. van Bussel Adv. Sci. Res., 12, 85-89, doi:10.5194/asr-12-85-2015, 2015 Remote sensing of the atmospheric variables with the use of Lidar is a relatively new technology field for wind resource assessment in wind energy. A review of the draft version of an international guideline (CD IEC 61400-12-1 Ed.2) used for wind energy purposes is performed and some extra atmospheric variables are taken into account for proper representation of the site. A measurement campaign with two Leosphere vertical scanning WindCube Lidars and metmast measurements is used for comparison of the uncertainty in wind speed measurements using the CD IEC 61400-12-1 Ed.2. The comparison revealed higher but realistic uncertainties. A simple model for Lidar beam averaging correction is demonstrated for understanding deviation in the measurements. It can be further applied for beam averaging uncertainty calculations in flat and complex terrain.

Description: Variability of atmospheric circulation patterns associated with large volume changes of the Baltic Sea A. Lehmann and P. Post Adv. Sci. Res., 12, 219-225, doi:10.5194/asr-12-219-2015, 2015 Salinity and stratification in the deep basins of the Baltic Sea are linked to the occurrence of Major Baltic Inflows (MBIs) of higher saline water of North Sea origin, which occur sporadically and transport higher saline and oxygenated water to deeper layers. Since the mid-1970s, the frequency and intensity of MBIs have decreased. They were completely absent between February 1983 and January 1993. However, in spite of the decreasing frequency of MBIs, there was no obvious decrease of larger Baltic Sea volume changes (LVCs). A LVC is defined by a total volume change of at least 100 km 3 . LVCs can be identified from the sea level changes at Landsort which is known to represent the mean sea level of the Baltic Sea very well. Strong inflows leading to LVCs are associated to a special sequence of atmospheric circulation patterns. Our analysis based on Jenkinson-Collison circulation (JCC) types confirms that most effective inflows occur if about a month before the main inflow period, eastern air flow with anticyclonic vorticity over the western Baltic prevails. These conditions reduce the mean sea level of the Baltic Sea and lead to an increased saline stratification in the Belt Sea area. An immediate period of strong to very strong westerly winds trigger the inflow and force LVCs/MBIs. The lack of MBIs coincide with a negative trend of eastern types and a parallel increase of western type JCCs.

Description: The impact of clouds, land use and snow cover on climate in the Canadian Prairies Alan K. Betts, Raymond L. Desjardins, and Devon E. Worth Adv. Sci. Res., 13, 37-42, doi:10.5194/asr-13-37-2016, 2016 Since 1953, the 15 climate stations on the Canadian Prairie have made unique hourly observations of opaque reflective cloud, as well as temperature, humidity, wind, precipitation and snow depth. These observations have shown that snow cover cools the local climate by 10 °C, and transforms how clouds drive the daily cycle of temperature and humidity. The replacement of summer fallow by intensive cropping has cooled and moistened the growing season climate and increased summer precipitation.

Description: Flux measurements by the NRC Twin Otter atmospheric research aircraft: 1987–2011 Raymond L. Desjardins, Devon E. Worth, J. Ian MacPherson, Matthew Bastian, and Ramesh Srinivasan Adv. Sci. Res., 13, 43-49, doi:10.5194/asr-13-43-2016, 2016 For 30 years, a Canadian research team has used an atmospheric research aircraft in measurement campaigns to improve our understanding of the controls on land-surface fluxes. The vertical flux of sensible and latent heat, momentum, and several trace gases were measured, along with supporting data. We document the data collected from 1987 to 2011, provide technical details of the measurement campaigns, present interesting results, and describe our approach to make the data publicly accessible.

Description: Large-eddy simulation of turbulent winds during the Fukushima Daiichi Nuclear Power Plant accident by coupling with a meso-scale meteorological simulation model Advances in Science and Research, 12, 127-133, 2015 Author(s): H. Nakayama, T. Takemi, and H. Nagai A significant amount of radioactive material was accidentally discharged into the atmosphere from the Fukushima Dai-ichi Nuclear Power Plant from 12 March 2011, which produced high contaminated areas over a wide region in Japan. In conducting regional-scale atmospheric dispersion simulations, the computer-based nuclear emergency response system WSPEEDI-II developed by Japan Atomic Energy Agency was used. Because this system is driven by a meso-scale meteorological (MM) model, it is difficult to reproduce small-scale wind fluctuations due to the effects of local terrain variability and buildings within a nuclear facility that are not explicitly represented in MM models. In this study, we propose a computational approach to couple an LES-based CFD model with a MM model for detailed simulations of turbulent winds with buoyancy effects under real meteorological conditions using turbulent inflow technique. Compared to the simple measurement data, especially, the 10 min averaged wind directions of the LES differ by more than 30 degrees during some period of time. However, distribution patterns of wind speeds, directions, and potential temperature are similar to the MM data. This implies that our coupling technique has potential performance to provide detailed data on contaminated area in the nuclear accidents.

Description: The VIADUC project: innovation in climate adaptation through service design Advances in Science and Research, 12, 199-205, 2015 Author(s): L. Corre, P. Dandin, D. L'Hôte, and F. Besson From the French National Adaptation to Climate Change Plan, the "Drias, les futurs du climat" service has been developed to provide easy access to French regional climate projections. This is a major step for the implementation of French Climate Services. The usefulness of this service for the end-users and decision makers involved with adaptation planning at a local scale is investigated. As such, the VIADUC project is: to evaluate and enhance Drias, as well as to imagine future development in support of adaptation. Climate scientists work together with end-users and a service designer. The designer's role is to propose an innovative approach based on the interaction between scientists and citizens. The chosen end-users are three Natural Regional Parks located in the South West of France. The latter parks are administrative entities which gather municipalities having a common natural and cultural heritage. They are also rural areas in which specific economic activities take place, and therefore are concerned and involved in both protecting their environment and setting-up sustainable economic development. The first year of the project has been dedicated to investigation including the questioning of relevant representatives. Three key local economic sectors have been selected: i.e. forestry, pastoral farming and building activities. Working groups were composed of technicians, administrative and maintenance staff, policy makers and climate researchers. The sectors' needs for climate information have been assessed. The lessons learned led to actions which are presented hereinafter.

Description: Urban warming in villages Advances in Science and Research, 12, 157-162, 2015 Author(s): J. Lindén, C.S.B. Grimmond, and J. Esper Long term meteorological records (〉 100 years) from stations associated with villages are generally classified as rural and assumed to have no urban influence. Using networks installed in two European villages, the local and microclimatic variations around two of these rural-village sites are examined. An annual average temperature difference ($\Delta{T}$) of 0.6 and 0.4 K was observed between the built-up village area and the current meteorological station in Geisenheim (Germany) and Haparanda (Sweden), respectively. Considerably larger values were recorded for the minimum temperatures and during summer. The spatial variations in temperature within the villages are of the same order as recorded over the past 100+ years in these villages (0.06 to 0.17 K/10 years). This suggests that the potential biases in the long records of rural-villages also warrant careful consideration like those of the more commonly studied large urban areas effects.

Description: MATISSE: an ArcGIS tool for monitoring and nowcasting meteorological hazards Advances in Science and Research, 12, 163-169, 2015 Author(s): V. Rillo, A. L. Zollo, and P. Mercogliano Adverse meteorological conditions are one of the major causes of accidents in aviation, resulting in substantial human and economic losses. For this reason it is crucial to monitor and early forecast high impact weather events. In this context, CIRA (Italian Aerospace Research Center) has implemented MATISSE (Meteorological AviaTIon Supporting SystEm), an ArcGIS Desktop Plug-in able to detect and forecast meteorological aviation hazards over European airports, using different sources of meteorological data (synoptic information, satellite data, numerical weather prediction models data). MATISSE presents a graphical interface allowing the user to select and visualize such meteorological conditions over an area or an airport of interest. The system also implements different tools for nowcasting of meteorological hazards and for the statistical characterization of typical adverse weather conditions for the airport selected.

Description: Methodologies to characterize uncertainties in regional reanalyses Advances in Science and Research, 12, 207-218, 2015 Author(s): M. Borsche, A. K. Kaiser-Weiss, P. Undén, and F. Kaspar When using climate data for various applications, users are confronted with the difficulty to assess the uncertainties of the data. For both in-situ and remote sensing data the issues of representativeness, homogeneity, and coverage have to be considered for the past, and their respective change over time has to be considered for any interpretation of trends. A synthesis of observations can be obtained by employing data assimilation with numerical weather prediction (NWP) models resulting in a meteorological reanalysis. Global reanalyses can be used as boundary conditions for regional reanalyses (RRAs), which run in a limited area (Europe in our case) with higher spatial and temporal resolution, and allow for assimilation of more regionally representative observations. With the spatially highly resolved RRAs, which exhibit smaller scale information, a more realistic representation of extreme events (e.g. of precipitation) compared to global reanalyses is aimed for. In this study, we discuss different methods for quantifying the uncertainty of the RRAs to answer the question to which extent the smaller scale information (or resulting statistics) provided by the RRAs can be relied on. Within the European Union's seventh Framework Programme (EU FP7) project Uncertainties in Ensembles of Regional Re-Analyses (UERRA) ensembles of RRAs (both multi-model and single model ensembles) are produced and their uncertainties are quantified. Here we explore the following methods for characterizing the uncertainties of the RRAs: (A) analyzing the feedback statistics of the assimilation systems, (B) validation against station measurements and (C) grids derived thereof, and (D) against gridded satellite data products. The RRA ensembles (E) provide the opportunity to derive ensemble scores like ensemble spread and other special probabilistic skill scores. Finally, user applications (F) are considered. The various methods are related to user questions they can help to answer.

Description: The new Euskalmet coastal–maritime warning system Santiago Gaztelumendi, Joseba Egaña, Pedro Liria, Manuel Gonzalez, José Antonio Aranda, and Pedro Anitua Adv. Sci. Res., 13, 91-96, doi:10.5194/asr-13-91-2016, 2016 This work presents the main characteristics of the Basque Meteorology Agency (Euskalmet) maritime–coastal risk warning system, with special emphasis on the latest updates, including a clear differentiation on specific warning messages addressing sea conditions for navigation purposes in the first 2 nautical miles, and expected coastal impacts. Some details of the warning bulletin for maritime and coastal risk situations are also presented, together with other communication products and strategies used in coastal and maritime severe episodes at the Basque coast. Today, three different aspects are included in the coastal–maritime risk warning system in Basque Country, related to the main potential severe events that affecting coastal activities. – "Galerna" risk relates to a sudden wind reversal that can severely affect coastal navigation and recreational activities. – "Navigation" risk relates to severe sea state conditions for 0–2 miles, affecting different navigation activities. – "Coastal impact" risk relates to adverse wave characteristics and tidal surges that induce flooding events and different impacts in littoral areas.

Description: Validation of three satellite-derived databases of surface solar radiation using measurements performed at 42 stations in Brazil Claire Thomas, Etienne Wey, Philippe Blanc, and Lucien Wald Adv. Sci. Res., 13, 81-86, doi:10.5194/asr-13-81-2016, 2016 Several satellite-derived solar surface irradiance databases provide long-term and homogeneously distributed information on the solar potential at ground level. This paper presents the validation results of three of these databases: HelioClim-3 (versions 4 and 5) and the CAMS radiation service, versus the measurements of 42 stations in Brazil. Despite a slight overestimation of the CAMS radiation service, the three databases are suitable for studies of the solar resources in Brazil.

Description: Delivery and communication of severe weather events in Basque Country: the Euskalmet case Santiago Gaztelumendi, Iñaki Orbe, Onintze Salazar, Ana Lopez, José Antonio Aranda, and Pedro Anitua Adv. Sci. Res., 13, 87-90, doi:10.5194/asr-13-87-2016, 2016 In this work we briefly introduce some aspects about delivery and communication of severe weather events in Basque Country, explaining what is considered severe weather by the Basque Meteorology Agency (Euskalmet) in the context of Basque Country. We include a short description of some products generated for different purposes during such events, presenting different aspects related with delivery and communication processes in the operational context of Euskalmet. We review some real examples on severe weather communication and message dissemination in Basque Country. Finally, some conclusions about our experience are presented.

Description: Forecasting wind power production from a wind farm using the RAMS model Advances in Science and Research, 12, 37-44, 2015 Author(s): L. Tiriolo, R. C. Torcasio, S. Montesanti, A. M. Sempreviva, C. R. Calidonna, C. Transerici, and S. Federico The importance of wind power forecast is commonly recognized because it represents a useful tool for grid integration and facilitates the energy trading. This work considers an example of power forecast for a wind farm in the Apennines in Central Italy. The orography around the site is complex and the horizontal resolution of the wind forecast has an important role. To explore this point we compared the performance of two 48 h wind power forecasts using the winds predicted by the Regional Atmospheric Modeling System (RAMS) for the year 2011. The two forecasts differ only for the horizontal resolution of the RAMS model, which is 3 km (R3) and 12 km (R12), respectively. Both forecasts use the 12 UTC analysis/forecast cycle issued by the European Centre for Medium range Weather Forecast (ECMWF) as initial and boundary conditions. As an additional comparison, the results of R3 and R12 are compared with those of the ECMWF Integrated Forecasting System (IFS), whose horizontal resolution over Central Italy is about 25 km at the time considered in this paper. v Because wind observations were not available for the site, the power curve for the whole wind farm was derived from the ECMWF wind operational analyses available at 00:00, 06:00, 12:00 and 18:00 UTC for the years 2010 and 2011. Also, for R3 and R12, the RAMS model was used to refine the horizontal resolution of the ECMWF analyses by a two-years hindcast at 3 and 12 km horizontal resolution, respectively. The R3 reduces the RMSE of the predicted wind power of the whole 2011 by 5% compared to R12, showing an impact of the meteorological model horizontal resolution in forecasting the wind power for the specific site.

Description: Data rescue of national and international meteorological observations at Deutscher Wetterdienst Advances in Science and Research, 12, 57-61, 2015 Author(s): F. Kaspar, B. Tinz, H. Mächel, and L. Gates Germany's national meteorological service (Deutscher Wetterdienst, DWD) houses in Offenbach and Hamburg huge archives of historical handwritten journals of weather observations. They comprise not only observations from Germany, but also of the oceans and land stations in many parts of the world. DWD works on the digitization and quality control of these archives. The current status is presented here.

Description: Investigation of balancing effects in long term renewable energy feed-in with respect to the transmission grid Advances in Science and Research, 12, 91-95, 2015 Author(s): A. Kies, K. Nag, L. von Bremen, E. Lorenz, and D. Heinemann A European power system mainly based on renewable sources will have dominant contributions from wind and solar power. However, wind and solar generation facilities have, due to the weather dependent nature of their resources, highly fluctuating feed-in profiles. To overcome the mismatch between power consumption and generation it is important to study and understand the generation patterns and balancing potentials. High temporally and spatially resolved long term weather data was used to simulate the feed-in from wind and photovoltaics for European countries for the years 2003 to 2012. We investigate storage energy and capacity needs in Europe in dependency of the generation mix from wind onshore, wind offshore and photovoltaics and the share of renewables. Furthermore we compute the storage energy and capacity needs for different transmission scenarios. We show that for unlimited transmission storage needs are reduced mostly by high wind offshore shares. We also show that higher shares above 100% of renewables can decrease the required storage capacity to a higher extent than the required storage energy.

Description: Waterspout cloud top detection using MSG SEVIRI infrared brightness temperature over the northern Ionian Sea, Greece Advances in Science and Research, 12, 45-49, 2015 Author(s): K. Papachristopoulou, I. T. Matsangouras, and P. T. Nastos Waterspouts pose a significant threat for coastal areas, maritime activities and structures and thus their study is essential. They are frequently occurring in the Mediterranean Sea and particularly in the northern coasts. A vulnerable area of waterspout formation is the Ionian Sea according to recent research and especially the water body around Corfu Island, Greece. The Laboratory of Climatology and Atmospheric Environment of the University of Athens has assembled a detailed database of waterspout events, providing additional information such as location and time of these events; valuable information for the methodology followed. In this study, the waterspout data base concerns events from 20 March 2007 to 31 December 2013. Thus, a total of 74 events were recorded and catalogued on 47 days, as there were days with multiple waterspout events. The aim of this study is to investigate the temporal evolution of brightness temperature on tops of waterspout parent clouds that triggered the formation of single or multiple waterspout events, based on the aforementioned database. The cloud top temperature was assessed by using channel at 10.8 μm MSG SEVIRI Level 1.5 Image Data product. The minimum brightness temperature of the cloud top around the waterspout location for four different examined radiuses was estimated during 60 min prior to and after waterspout formation. Results are illustrated in terms of seasonal analysis. During autumn season a decrease of brightness temperature (colder values) was detected at waterspout parent cloud close to waterspout formation.

Description: Evaluation of WRF model seasonal forecasts for tropical region of Singapore Advances in Science and Research, 12, 69-72, 2015 Author(s): J. Singh, K. Yeo, X. Liu, R. Hosseini, and J. R. Kalagnanam The Weather and Research Forecast (WRF) model is evaluated for the monsoon and inter-monsoon seasons over the tropical region of Singapore. The model configuration, physical parameterizations and performance results are described in this paper. In addition to the ready-to-use data available with the WRF model, the model configuration includes high resolution MODIS land use (500 m horizontal resolution) and JPL-NASA sea surface temperature (1 km horizontal resolution) data. The model evaluation is performed against near surface observations for temperature, relative humidity, wind speed and direction, available from a dense network of weather monitoring stations across Singapore. It is found that the high resolution data sets bring significant improvement in the model forecasts. The results also indicate that the model forecasts are more accurate in the monsoon seasons compared to the inter-monsoon seasons.

Description: Ten years water and energy surface balance from the CNR-ISAC micrometeorological station in Salento peninsula (southern Italy) Advances in Science and Research, 12, 121-125, 2015 Author(s): P. Martano, C. Elefante, and F. Grasso Data of surface-atmosphere energy and water transfer from a ten years (2003–2013) period of activity of the ISAC-Lecce micrometeorological station ( http://www.basesperimentale.le.isac.cnr.it ) have been analyzed: to the authors' knowledge this is the first decadal data set of surface-atmosphere transfer in Salento peninsula. The surface energy budget shows a tendency to a positive bias possibly due to several reasons that require more investigations. Some suitable indices related to the surface water balance, such as the precipitation intensity, the aridity index and the ground water infiltration fraction have been calculated. Possible trends of these annual averages in the decadal period are considered, also taking into account the statistical uncertainty associated to measurement errors and missing data. The results indicate a significant increasing in the precipitation intensity together with an experimental evidence of increasing of the ground water infiltration in the measurement area, that is in agreement with recent estimations for the whole Salento peninsula. On the other hand, recent studies show that seawater intrusion and salinization of the deep underground aquifer keep increasing in the same period.

Description: Corrigendum to "Lidar uncertainty and beam averaging correction" published in Adv. Sci. Res., 12, 85–89, 2015 Advances in Science and Research, 12, 135-135, 2015 Author(s): A. Giyanani, W. Bierbooms, and G. van Bussel No abstract available.

Description: Comparison of HOMER and ACMANT homogenization methods using a central Pyrenees temperature dataset Advances in Science and Research, 12, 111-119, 2015 Author(s): N. Pérez-Zanón, J. Sigró, P. Domonkos, and L. Ashcroft The aim of this research is to compare the results of two modern multiple break point homogenization methods, namely ACMANT and HOMER, over a Pyrenees temperature dataset in order to detect differences between their outputs which can affect future studies. Both methods are applied to a dataset of 44 monthly maximum and minimum temperature series placed around central Pyrenees and covering the 1910–2013 period. The results indicate that the automatic method ACMANT produces credible results. While HOMER detects more breaks supported by metadata, this method is also more dependent on the user skill and thus sensitive to subjective errors.

Description: The FORBIO Climate data set for climate analyses Advances in Science and Research, 12, 103-109, 2015 Author(s): C. Delvaux, M. Journée, and C. Bertrand In the framework of the interdisciplinary FORBIO Climate research project, the Royal Meteorological Institute of Belgium is in charge of providing high resolution gridded past climate data (i.e. temperature and precipitation). This climate data set will be linked to the measurements on seedlings, saplings and mature trees to assess the effects of climate variation on tree performance. This paper explains how the gridded daily temperature (minimum and maximum) data set was generated from a consistent station network between 1980 and 2013. After station selection, data quality control procedures were developed and applied to the station records to ensure that only valid measurements will be involved in the gridding process. Thereafter, the set of unevenly distributed validated temperature data was interpolated on a 4 km × 4 km regular grid over Belgium. The performance of different interpolation methods has been assessed. The method of kriging with external drift using correlation between temperature and altitude gave the most relevant results.

Description: Yearly changes in surface solar radiation in New Caledonia Advances in Science and Research, 12, 1-4, 2015 Author(s): P. Blanc, C. Coulaud, and L. Wald New Caledonia experiences a decrease in surface solar irradiation since 2004. It is of order of 4% of the mean yearly irradiation over the 10 years period: 2004–2013, and amounts to −9 W m −2 . The preeminent roles of the changes in cloud cover and to a lesser extent, those in aerosol optical depth on the decrease in yearly irradiation are evidenced. The study highlights the role of data sets offering a worldwide coverage in understanding changes in solar radiation and planning large solar energy plants such as the ICOADS (International Comprehensive Ocean-Atmosphere Data Set) of the NOAA and MACC (Monitoring Atmosphere Composition and Climate) data sets combined with the McClear model.

Description: Estimating the photosynthetically active radiation under clear skies by means of a new approach Advances in Science and Research, 12, 5-10, 2015 Author(s): W. Wandji Nyamsi, B. Espinar, P. Blanc, and L. Wald The k -distribution method and the correlated- k approximation of Kato et al. (1999) is a computationally efficient approach originally designed for calculations of the broadband solar radiation by dividing the solar spectrum in 32 specific spectral bands from 240 to 4606 nm. This paper describes a technique for an accurate assessment of the photosynthetically active radiation (PAR) from 400 to 700 nm at ground level, under clear-sky conditions using twelve of these spectral bands. It is validated against detailed spectral calculations of the PAR made by the radiative transfer model libRadtran. For the direct and global PAR irradiance, the bias is −0.4 W m −2 (−0.2%) and −4 W m −2 (−1.3%) and the root mean square error is 1.8 W m −2 (0.7%) and 4.5 W m −2 (1.5%). For the direct and global Photosynthetic Photon Flux Density, the biases are of about +10.3 μmol m −2 s −1 (+0.8%) and 1.9 μmol m −2 s −1 (−0.1%) respectively, and the root mean square error is 11.4 μmol m −2 s −1 (0.9%) and 4.0 μmol m −2 s −1 (0.3%). The correlation coefficient is greater than 0.99. This technique provides much better results than two state-of-the-art empirical methods computing the daily mean of PAR from the daily mean of broadband irradiance.

Description: UV and global irradiance measurements and analysis during the Marsaxlokk (Malta) campaign Advances in Science and Research, 12, 147-155, 2015 Author(s): J. Bilbao, R. Román, C. Yousif, D. Mateos, and A. de Miguel A solar radiation measurement campaign was performed in the south-eastern village of Marsaxlokk (35°50' N; 14°33' E; 10 m a.s.l), Malta, between 15 May and 15 October 2012. Erythemal solar radiation data (from a UVB-1 pyranometer), and total horizontal solar radiation (global and diffuse components) from two CM21 pyranometer were recorded. A comparison of atmospheric compounds from ground measurements and satellites shows that TOC (total ozone column) data from the Ozone Monitoring Instrument OMI, TOMS and DOAS algorithms correlate well with ground-based recorded data. The water vapour column and the aerosol optical depth at 550 nm show a significant correlation at the confidence level of 99 %. Parametric models for evaluating the solar UV erythemal (UVER), global (G) and diffuse (D) horizontal irradiances are calibrated, from which aerosol effects on solar irradiance are evaluated using the Aerosol Modification Factor (AMF). The AMF UVER values are lower than AMF G , indicating a greater aerosol effect on UVER than on global solar irradiance. In this campaign, several dust event trajectories are identified by means of the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and by synoptic conditions for characterizing desert dust events. Hence, changes in the UV index due to atmospheric aerosols are described.

Description: Precipitation climate maps of Belgium Advances in Science and Research, 12, 73-78, 2015 Author(s): M. Journée, C. Delvaux, and C. Bertrand Investigations are conducted to best estimate precipitation climate maps over Belgium from daily observations available for the period 1981–2010. Several mapping approaches are compared in a cross-validation exercise. These approaches differ by several aspects and in particular by the order in which the temporal aggregation (i.e. computation of climate mean values from daily data) and spatial interpolation steps are performed, and by the integration of ancillary information in the spatial interpolation method. The selected approach is used to derive a large panel of climate maps. In particular, the main spatio-temporal features of the annual cycle of rainfall in Belgium are extracted by principal component analysis (PCA).

Description: An overview of the use of Twitter in National Weather Services Advances in Science and Research, 12, 141-145, 2015 Author(s): S. Gaztelumendi, M. Martija, O. Principe, and V. Palacio Twitter is a service that enables users to post messages ("tweets") of up to 140 characters supporting a variety of communicative practices. In this paper we analyze different aspects related to the use of Twitter in different National Meteorological Services (NMS) worldwide. Firstly, we will review the general position of NMS worldwide regarding the use of Twitter technology. Secondly, we will focus on different practices of some selected meteorological services. Thirdly, we will deal specifically with the Basque Meteorology Agency (Euskalmet) case. Finally some conclusions are presented.

Description: Diurnal temperature cycle deduced from extreme daily temperatures and impact over a surface reanalysis system Advances in Science and Research, 12, 137-140, 2015 Author(s): F. Besson, E. Bazile, C. Soci, J.-M. Soubeyroux, G. Ouzeau, and M. Perrin Due to the evolution of the observation network, hourly 2 m temperature analysis performed by reanalysis systems shows temporal inhomogeneities. The observation network gap is less present for extreme daily temperature observations. In order to reduce inhomogeneities and enable a climatological use of temperature analysis, information from extreme temperatures could be useful. In this study, the diurnal temperature cycle has been reconstructed for stations which only record extreme temperatures. These new "pseudo" hourly temperature observations are then provided to the analysis system. Two methods have been used to deduce hourly temperatures from extremes and compared to real observations. The results have shown that using those new pseudo-observations as an input for two different reanalysis systems enables reducing the bias in temperature analysis.

Description: On the effective solar zenith and azimuth angles to use with measurements of hourly irradiation P. Blanc and L. Wald Adv. Sci. Res., 13, 1-6, doi:10.5194/asr-13-1-2016, 2016 Time series of hourly measurements or modelled values of surface solar irradiation are increasingly available. Currently, no solar zenith and azimuth angles are associated to each measurement whereas such angles are necessary for handling the measured or modelled irradiations. A method is proposed to assess such angles with a great accuracy. It makes use of two modelled time-series that can be computed using the web site www.soda-pro.com for any site in the world.

Description: Quality control of the RMI's AWS wind observations Cédric Bertrand, Luis González Sotelino, and Michel Journée Adv. Sci. Res., 13, 13-19, doi:10.5194/asr-13-13-2016, 2016 This paper describes the quality control procedures developed at the Royal Meteorological Institute of Belgium (RMI) to ensure the accuracy and reliability of the wind observations performed within the Automatic Weather Stations network operated by RMI.

Description: Intense air-sea exchange and heavy rainfall: impact of the northern Adriatic SST P. Stocchi and S. Davolio Adv. Sci. Res., 13, 7-12, doi:10.5194/asr-13-7-2016, 2016 Three heavy rain events over NE Alps were simulated using a high-resolution model to evaluate the effect of the SST of the Adriatic Sea. These preliminary results show that SST influences the surface heat fluxes over the sea, but does not necessary affect the vertical integrated water vapour flux across the coast. The response of heavy precipitation to a SST change is complex: SST affects the PBL characteristics and thus the flow dynamics and its interaction with orography.

Description: Validation of the McClear clear-sky model in desert conditions with three stations in Israel Mireille Lefèvre and Lucien Wald Adv. Sci. Res., 13, 21-26, doi:10.5194/asr-13-21-2016, 2016 The new CAMS (Copernicus Atmosphere Monitoring Service) McClear service is a practical easy-to-use tool to estimate the solar direct and global irradiances received at ground level in cloud-free conditions at any place any time. This article presents validation against 1 min measurements made at three very close stations in Israel in desert conditions. The good results demonstrate the accuracy of McClear and its ability to capture the temporal and spatial variability of the irradiance field.

Description: Variability of atmospheric circulation patterns associated with large volume changes of the Baltic Sea Advances in Science and Research, 12, 219-225, 2015 Author(s): A. Lehmann and P. Post Salinity and stratification in the deep basins of the Baltic Sea are linked to the occurrence of Major Baltic Inflows (MBIs) of higher saline water of North Sea origin, which occur sporadically and transport higher saline and oxygenated water to deeper layers. Since the mid-1970s, the frequency and intensity of MBIs have decreased. They were completely absent between February 1983 and January 1993. However, in spite of the decreasing frequency of MBIs, there was no obvious decrease of larger Baltic Sea volume changes (LVCs). A LVC is defined by a total volume change of at least 100 km 3 . LVCs can be identified from the sea level changes at Landsort which is known to represent the mean sea level of the Baltic Sea very well. Strong inflows leading to LVCs are associated to a special sequence of atmospheric circulation patterns. Our analysis based on Jenkinson-Collison circulation (JCC) types confirms that most effective inflows occur if about a month before the main inflow period, eastern air flow with anticyclonic vorticity over the western Baltic prevails. These conditions reduce the mean sea level of the Baltic Sea and lead to an increased saline stratification in the Belt Sea area. An immediate period of strong to very strong westerly winds trigger the inflow and force LVCs/MBIs. The lack of MBIs coincide with a negative trend of eastern types and a parallel increase of western type JCCs.

Description: The verification of seasonal precipitation forecasts for early warning in Zambia and Malawi Advances in Science and Research, 12, 31-36, 2015 Author(s): O. Hyvärinen, L. Mtilatila, K. Pilli-Sihvola, A. Venäläinen, and H. Gregow We assess the probabilistic seasonal precipitation forecasts issued by Regional Climate Outlook Forum (RCOF) for the area of two southern African countries, Malawi and Zambia from 2002 to 2013. The forecasts, issued in August, are of rainy season rainfall accumulations in three categories (above normal, normal, and below normal), for early season (October–December) and late season (January–March). As observations we used in-situ observations and interpolated precipitation products from Global Precipitation Climatology Project (GPCP), Global Precipitation Climatology Centre (GPCC), and Climate Prediction Centre (CPC) Merged Analysis of Precipitation (CMAP). Differences between results from different data products are smaller than confidence intervals calculated by bootstrap. We focus on below normal forecasts as they were deemed to be the most important for society. The well-known decomposition of Brier score into three terms (Reliability, Resolution, and Uncertainty) shows that the forecasts are rather reliable or well-calibrated, but have a very low resolution; that is, they are not able to discriminate different events. The forecasts also lack sharpness as forecasts for one category are rarely higher than 40 % or less than 25 %. However, these results might be unnecessarily pessimistic, because seasonal forecasts have gone through much development during the period when the forecasts verified in this paper were issued, and forecasts using current methodology might have performed better.

Description: 〈b〉Numerical simulations of winter cold damage to citrus fruits using the WRF model〈/b〉〈br〉 Yukitaka Ohashi and Hideki Ueyama〈br〉 Adv. Sci. Res., 16, 1-6, https://doi.org/10.5194/asr-16-1-2019, 2019〈br〉 〈p〉To numerically assess winter cold damages of citrus fruits, a cold duration of sub-zero temperature was simulated using a high resolution configuration (500 m horizontal grid spacing) of the WRF numerical weather prediction system. Japanese citrus is often cultivated on slopes made of a small hill and a valley. Hence, a high resolution spatial configuration is needed to simulate cold durations at complex micro-topographies. In this study, detailed cold duration maps for sub-zero temperatures were produced to assess the spatial difference of cold duration, as an example of a winter cold surge attack in west Japan in 2011. Our findings suggest that the recorded temperature (by automatic observation of the Japan Meteorological Agency), which was observed at a flat coastal plain, may underestimate cold damage risk for citrus fruit on narrow slopes, valleys and hilly areas.〈/p〉

Description: 〈b〉Twitter and weather services〈/b〉〈br〉 Santiago Gaztelumendi, Maialen Martija, and Olatz Principe〈br〉 Adv. Sci. Res., 15, 239-243, https://doi.org/10.5194/asr-15-239-2018, 2018〈br〉 〈p〉This work focuses on the analysis of the use of Twitter by different weather services around the world. During the last few years the availability of mobile phones connected to the Internet has become a global reality. Likewise, the use of different social networks has been popularized and extended with different purposes including social communication. In this context most meteorological weather services have been using some of these social tools in order to improve their services for the general public and specific users. Twitter is a social tool that enables users to post messages (〈q〉tweets〈/q〉) of up to 280 characters (up to 140 before November 2017), supporting a wide variety of communicative practices. Twitter is an opportunity not only to spread messages without intermediaries, but also interact in real time with users. Here we present a study of different aspects related to the use of Twitter in diverse weather services worldwide and their evolution during the year 2016.〈/p〉

Description: 〈b〉A new framework for probabilistic seasonal forecasts based on circulation type classifications and driven by an ensemble global model〈/b〉〈br〉 Gianni Messeri, Riccardo Benedetti, Alfonso Crisci, Bernardo Gozzini, Matteo Rossi, Roberto Vallorani, and Giampiero Maracchi〈br〉 Adv. Sci. Res., 15, 183-190, https://doi.org/10.5194/asr-15-183-2018, 2018〈br〉 This new framework for high resoluted seasonal forecast allows an easier use of the information contained in the complex system of atmospheric circulations through their reduction to a limited number of circulation types starting from a global ensemble model. Further investigations are ongoing in order to lead predictions of the risk of heavy rainfall, drought or heat waves, all important parameters for agriculture, water management and severe weather risk assessment.

Description: 〈b〉1845–2016 gridded dataset of monthly precipitation over the upper Adda river basin: a comparison with runoff series〈/b〉〈br〉 Alice Crespi, Michele Brunetti, Maurizio Maugeri, Roberto Ranzi, and Massimo Tomirotti〈br〉 Adv. Sci. Res., 15, 173-181, https://doi.org/10.5194/asr-15-173-2018, 2018〈br〉 The gridded dataset of 1845–2016 monthly precipitation series over the upper Adda river basin is presented. It allows to study the evolution of the precipitation regime over the region and to reconstruct extreme past events. The areal 1845–2016 annual precipitation series over the basin is in overall agreement with annual runoff. While the precipitation series shows no significant trend, a significant decrease is pointed out for runoff, probably driven by both natural and anthropic causes.

Description: 〈b〉Current gust forecasting techniques, developments and challenges〈/b〉〈br〉 Peter Sheridan〈br〉 Adv. Sci. Res., 15, 159-172, https://doi.org/10.5194/asr-15-159-2018, 2018〈br〉 Gusts represent short-lived extremes within the time variation of the wind. Despite their short duration, they are responsible for the majority of damage and disruption due to wind. This study reviews new literature and innovative methods regarding the forecasting of gusts for weather and climate applications, the challenges and benefits that come with increasing resolution in computer models of the weather, and areas, such as wind power, where gust forecasting attains increasing importance.

Description: 〈b〉Strategy for generation of climate change projections feeding Spanish impact community〈/b〉〈br〉 María Pilar Amblar-Francés, María Asunción Pastor-Saavedra, María Jesús Casado-Calle, Petra Ramos-Calzado, and Ernesto Rodríguez-Camino〈br〉 Adv. Sci. Res., 15, 217-230, https://doi.org/10.5194/asr-15-217-2018, 2018〈br〉 The Spanish State Meteorological Agency (AEMET) has been producing since 2006 a set of reference downscaled regional climate change projections over Spain. Its strategy aims at exploiting all the available sources of information on climate change projections. In the future this service aims at complementing the Copernicus Climate Change Service (C3S) in terms of resolution, expression of uncertainty, visualization, tailored adjustments and reinforcement of links with national users.

Description: 〈b〉Description of a coastal impact event in Basque Country: the 9 February 2016 case〈/b〉〈br〉 Santiago Gaztelumendi, Joseba Egaña, Pedro Liria, and José A. Aranda〈br〉 Adv. Sci. Res., 15, 137-143, https://doi.org/10.5194/asr-15-137-2018, 2018〈br〉 〈p〉In this work we analysed a case from 9 February 2016 from two points of view, the meteorological–ocean characteristics of the event and the damage produced during the episode in the Basque coastal area. On 7 and 8 February 2016 an intense zonal circulation was established in the Atlantic, with very strong westerly winds (over 100 km h〈span〉〈sup〉−1〈/sup〉〈/span〉) and high fetch (more than 2000 km). As a consequence a strong swell (over 7 m) arrived on the Basque coast affecting littoral areas. The wave characteristics are particularly energetic during the morning of the 9 February, which had a significant wave of 9.5 m and a peak period of 20 s in deep water (Donostia buoy). The arrival of these energetic waves coincides with high tide during spring when the sea level reaches 4.69 m in the Port of Bilbao. Overtopping indexes exceeded red-level thresholds established within the Euskalmet coastal warning system and the wave impact resulted in relevant damage (more than EUR 3 million) in different littoral areas. This event is the first red-level case since the new Euskalmet warning procedure became operational at the beginning of 2015.〈/p〉

Description: 〈b〉An explicit method of mesoscale convective storm prediction for the central region of Russia〈/b〉〈br〉 Inna M. Gubenko, Maria M. Kurbatova, and Konstantin G. Rubinstein〈br〉 Adv. Sci. Res., 15, 213-216, https://doi.org/10.5194/asr-15-213-2018, 2018〈br〉 〈p〉This work presents simulation results of the storm observed on the 13–14 July 2016 over the Central region of Russia. The Cumulonimbus cloud (Cb) electrification model coupled with the numerical weather prediction model WRF-ARW were used for this study. The prognostic values of the electric field magnitude were compared with observations. Forecast scores were obtained. The results show that the proposed approach of explicit modelling of the electric field is applicable to short-term forecasting of intense convection and passage tracking of storms. Obtaining varying values of the electric field could help to identify the diversity of hazardous weather phenomena associated with convection.〈/p〉

Description: 〈b〉Monthly solar radiation in the tropical Atlantic Ocean: Can its spatial variations be captured by the current configuration of the PIRATA moorings?〈/b〉〈br〉 Mélodie Trolliet and Lucien Wald〈br〉 Adv. Sci. Res., 15, 127-136, https://doi.org/10.5194/asr-15-127-2018, 2018〈br〉 〈p〉The present work aims at contributing to the proper design of networks of measuring moorings with regard to the downwelling solar irradiance at surface (DSIS). Considering the yearly profiles of the monthly DSIS, this article studies whether the 17 moorings within the existing PIRATA network are well geographically distributed so that they capture the spatial variations of the yearly profiles in the tropical Atlantic Ocean. A clustering technique is performed onto the HelioClim-3v5 satellite-derived gridded dataset of DSIS spanning 12 years, thus yielding 17 zones of similar yearly profiles. It was found that the mean yearly profiles of several zones are similar to the measured ones at the three moorings having enough measurements to perform the comparison. Zones have clear connections with the climatology of the region and circulation regimes. The geographical distribution of the moorings has been analysed with regard to the zoning. In the northern region of the tropical basin, each zone contains at least one PIRATA mooring. Hence, the configuration of the PIRATA network is appropriate to reflect the spatial variations of the yearly profiles in this northern part. In the southern basin, the coverage is less complete; several zones do not contain any PIRATA mooring. Thus, the network does not capture the spatial variations of the yearly profiles and this may induce misinterpretation of the PIRATA measurements at synoptic scales. It was also found that the computation of latitudinal or longitudinal averages of irradiance may be wrong if based solely on measurements from moorings without taking into account the spatial representativeness of a mooring.〈/p〉

Description: 〈b〉The INTENSE project: using observations and models to understand the past, present and future of sub-daily rainfall extremes〈/b〉〈br〉 Stephen Blenkinsop, Hayley J. Fowler, Renaud Barbero, Steven C. Chan, Selma B. Guerreiro, Elizabeth Kendon, Geert Lenderink, Elizabeth Lewis, Xiao-Feng Li, Seth Westra, Lisa Alexander, Richard P. Allan, Peter Berg, Robert J. H. Dunn, Marie Ekström, Jason P. Evans, Greg Holland, Richard Jones, Erik Kjellström, Albert Klein-Tank, Dennis Lettenmaier, Vimal Mishra, Andreas F. Prein, Justin Sheffield, and Mari R. Tye〈br〉 Adv. Sci. Res., 15, 117-126, https://doi.org/10.5194/asr-15-117-2018, 2018〈br〉 Measurements of sub-daily (e.g. hourly) rainfall totals are essential if we are to understand short, intense bursts of rainfall that cause flash floods. We might expect the intensity of such events to increase in a warming climate but these are poorly realised in projections of future climate change. The INTENSE project is collating a global dataset of hourly rainfall measurements and linking with new developments in climate models to understand the characteristics and causes of these events.

Description: 〈b〉Comparison of radiation parametrizations within the HARMONIE–AROME NWP model〈/b〉〈br〉 Laura Rontu and Anders V. Lindfors〈br〉 Adv. Sci. Res., 15, 81-90, https://doi.org/10.5194/asr-15-81-2018, 2018〈br〉 Global radiation forecasts by HARMONIE-AROME numerical weather prediction model were compared to observations over Finland in spring 2017 when convective clouds, rain and snow showers were frequent. In HARMONIE-AROME, three different schemes for parametrization of the atmospheric radiation transfer are available. Differences between the schemes and observations showed up especially as variations in the hourly scale. The results by the schemes were closer to each other than to the observations.

Description: 〈b〉Mapping users' expectations regarding extended-range forecasts〈/b〉〈br〉 Tiina Ervasti, Hilppa Gregow, Andrea Vajda, Terhi K. Laurila, and Antti Mäkelä〈br〉 Adv. Sci. Res., 15, 99-106, https://doi.org/10.5194/asr-15-99-2018, 2018〈br〉 An online survey was used to map the needs and preferences of the Finnish general public about extended-range forecasts and their presentation. Survey results guided the co-design process of novel extended-range forecasts in the project. The respondents considered that the tailored extended-range forecasts would be beneficial in planning activities, preparing for weather risks and scheduling everyday life. They also valued impact information higher than advice on how to prepare for the impacts.

Description: 〈b〉Crowdsourcing of weather observations at national meteorological and hydrological services in Europe〈/b〉〈br〉 Thomas Krennert, Georg Pistotnik, Rainer Kaltenberger, and Christian Csekits〈br〉 Adv. Sci. Res., 15, 71-76, https://doi.org/10.5194/asr-15-71-2018, 2018〈br〉 National Meteorological and Hydrological Services (NMHSs) increase their efforts to deliver impact-based weather forecasts and warnings. At the same time, a desired increase in cost-efficiency prompts these services to automatize their weather station networks and to reduce the number of human observers, which leads to a lack of 〈q〉ground truth〈/q〉 information about weather phenomena and their impact. A possible alternative is to encourage the general public to submit weather observations, which may include crucial information especially in high-impact situations. 〈br〉〈br〉 We wish to provide an overview of the state and properties of existing collaborations between NMHSs and voluntary weather observers or storm spotters across Europe. For that purpose, we performed a survey among 30 European NMHSs, from which 22 NMHSs returned our questionnaire. This study summarizes the most important findings and evaluates the use of 〈q〉crowdsourced〈/q〉 information. 86 % of the surveyed NMHSs utilize information provided by the general public, 50 % have established official collaborations with spotter groups, and 18 % have formalized them. The observations are most commonly used for a real-time improvement of severe weather warnings, their verification, and an establishment of a climatology of severe weather events. 〈br〉〈br〉 The importance of these volunteered weather and impact observations has strongly risen over the past decade. We expect that this trend will continue and that storm spotters will become an essential part in severe weather warning, like they have been for decades in the United States of America. A rising number of incoming reports implies that quality management will become an increasing issue, and we finally discuss an idea how to handle this challenge.

Description: 〈b〉The “Meteo-show” in the newspapers〈/b〉〈br〉 Iñaki Orbe and Santiago Gaztelumendi〈br〉 Adv. Sci. Res., 15, 245-249, https://doi.org/10.5194/asr-15-245-2018, 2018〈br〉 〈p〉In this work we focus on what may be described as one of the worst journalist practices when dealing with severe weather: the “Meteo-Show”, considered as the more or less extended informative practice whose main objective is to increase the news impact regardless of the veracity and the exactitude of the weather facts. In this work we analysed such practices on newspapers highlighting different journalist resources used in written press when dealing with weather for attracting attention and promoting impact. The growing public interest in weather causes that journalists often focus on this topic. But as it could happen with other issues, mistakes, inaccuracies, sensationalism and exaggerations have also reached meteorology related written news. This wrongdoing is especially present and dangerous when episodes of adverse nature are treated. In this paper we present some keys to identify “Meteo-show” in the context of written press. We analysed some examples from real news articles published in different newspapers, in order to understand the motivation of these practices. Finally we present some conclusions and recommendations to deal with this subject.〈/p〉

Description: 〈b〉Comparing climate change indices between a northern (arid) and a southern (humid) basin in Mexico during the last decades〈/b〉〈br〉 Martín José Montero-Martínez, Julio Sergio Santana-Sepúlveda, Naydú Isabel Pérez-Ortiz, Óscar Pita-Díaz, and Salvador Castillo-Liñan〈br〉 Adv. Sci. Res., 15, 231-237, https://doi.org/10.5194/asr-15-231-2018, 2018〈br〉 This study provides a comparison between several climate change indices trends of two very different basins in Mexico, one located in the northern arid region (the Conchos River basin) and the other in the southern humid area (the Usumacinta River basin). A clear warming signal was found for the two basins in addition to an increment in the diurnal temperature range, in agreement with other studies in Mexico. Also, the Conchos basin was found to be more humid and the Usumacinta drier.

Description: 〈b〉Case study of the winter 2013/2014 extreme wave events off the west coast of Ireland〈/b〉〈br〉 Jelena Janjić, Sarah Gallagher, and Frédéric Dias〈br〉 Adv. Sci. Res., 15, 145-157, https://doi.org/10.5194/asr-15-145-2018, 2018〈br〉 This study examines the synoptic conditions around Ireland during the winter of 2013/2014, which produced record-breaking sea states and severe coastal damage. Using a wave model, we analysed four of the most energetic storms providing an overview of the height, directionality and periodicity of the waves. This study provides important information for the development of renewable ocean energy extraction, where deployment location selection and survivability are a primary concern.

Description: 〈b〉Creating a proof-of-concept climate service to assess future renewable energy mixes in Europe: An overview of the C3S ECEM project〈/b〉〈br〉 Alberto Troccoli, Clare Goodess, Phil Jones, Lesley Penny, Steve Dorling, Colin Harpham, Laurent Dubus, Sylvie Parey, Sandra Claudel, Duc-Huy Khong, Philip E. Bett, Hazel Thornton, Thierry Ranchin, Lucien Wald, Yves-Marie Saint-Drenan, Matteo De Felice, David Brayshaw, Emma Suckling, Barbara Percy, and Jon Blower〈br〉 Adv. Sci. Res., 15, 191-205, https://doi.org/10.5194/asr-15-191-2018, 2018〈br〉 The European Climatic Energy Mixes, an EU Copernicus Climate Change Service project, has produced, in close collaboration with prospective users, a proof-of-concept climate service, or Demonstrator, designed to enable the energy industry assess how well different energy supply mixes in Europe will meet demand, over different time horizons (from seasonal to long-term decadal planning), focusing on the role climate has on the mixes. Its concept, methodology and some results are presented here.

Description: 〈b〉Evaluation of radiosonde humidity sensors at low temperature using ultralow-temperature humidity chamber〈/b〉〈br〉 Byung Il Choi, Sang-Wook Lee, Sang-Bong Woo, Jong Chul Kim, Yong-Gyoo Kim, and Seung Gu Yang〈br〉 Adv. Sci. Res., 15, 207-212, https://doi.org/10.5194/asr-15-207-2018, 2018〈br〉 Accurate measurements of temperature and water vapor in the upper-air are of great interest in relation to weather prediction and climate change. Those measurements are mostly conducted using radiosondes. The sensitivity characteristic and response time of radiosonde humidity sensors were investigated at low temperature, using developed ultralow-temperature humidity chamber. This work will improve the accuracy and reliability of the upper-air observation data.

Description: 〈b〉Bias adjustment for threshold-based climate indicators〈/b〉〈br〉 Peter Hoffmann, Christoph Menz, and Arne Spekat〈br〉 Adv. Sci. Res., 15, 107-116, https://doi.org/10.5194/asr-15-107-2018, 2018〈br〉 The adjustment of bias, i.e., systematic errors, of climate models are a necessity when comparing results of an ensemble of these models. Usually, the meteorological parameters such as temperature or rainfall amounts themselves are subject to bias adjustments. We present a new method to apply bias adjustment to so-called climate indicators which are derived from those parameters, e.g., the number of days warmer than 30 °C or the number of days with more than 20 mm of rain.

Description: 〈b〉Trusted Spotter Network Austria – a new standard to utilize crowdsourced weather and impact observations〈/b〉〈br〉 Thomas Krennert, Rainer Kaltenberger, Georg Pistotnik, Alois M. Holzer, Franz Zeiler, and Mathias Stampfl〈br〉 Adv. Sci. Res., 15, 77-80, https://doi.org/10.5194/asr-15-77-2018, 2018〈br〉 〈p〉Information from voluntary storm spotters has been an increasingly important part for the severe weather warning process at the Zentralanstalt für Meteorologie and Geodynamik (ZAMG), Austria's National Weather Service, for almost 15 years. In 2010 a collaboration was formalized and an annual training was established to educate voluntary observers into “Trusted Spotters”. The return of this investment is a higher credibility of their observations after these spotters have undergone a basic meteorological training and have become aware of their responsibility.〈/p〉 〈p〉The European Severe Storms Laboratory (ESSL) was included to this collaboration to adopt their successful quality control system of severe weather reports, which is employed in the European Severe Weather Database ESWD. That way, reports from Trusted Spotters automatically obtain a higher quality flag, which enables a faster processing by forecasters on duty for severe weather warnings, when time is a critical issue. The concept of combining training for voluntary storm spotters and a thorough quality management was recognized as a “Best Practice Model” by the European Meteorological Society.〈/p〉 〈p〉We propose to apply this concept also in other European countries and present its advancement into an even broader, pan-European approach. The European Weather Observer app EWOB, recently released by ESSL, provides a novel and easy-to-handle tool to submit weather and respective impact observations. We promote its use to provide better data and information for a further real-time improvement of severe weather warnings.〈/p〉

Description: 〈b〉Comparison of seven wind gust parameterizations over the European part of Russia〈/b〉〈br〉 Maria Kurbatova, Konstantin Rubinstein, Inna Gubenko, and Grigory Kurbatov〈br〉 Adv. Sci. Res., 15, 251-255, https://doi.org/10.5194/asr-15-251-2018, 2018〈br〉 〈p〉Wind gusts are extreme events which can cause severe damage. Gusts can reach significant values even during medium winds. However, numerical atmospheric models are designed to reproduce average wind speed, not gusts. There are several approaches to estimating wind gusts. Seven different methods are applied to WRF-ARW model output. Results are compared to high-frequency wind speed measurements using ultrasonic anemometers and temperature profiler measurement at the same point in Moscow. Data gathered from synoptic station network over the European part of Russia were also included in the analysis to increase the statistics. None of the wind gust estimation methods shows best results at every skill score. The proposed hybrid method shows good balance between the probability of detection and the false alarm ratio estimates.〈/p〉

Description: 〈b〉Learning and teaching about seasonal climate forecasts: a Mediterranean educational experience toward operational climate services〈/b〉〈br〉 Vieri Tarchiani, Massimiliano Pasqui, Patrick Parrish, Elena Rapisardi, Edmondo Di Giuseppe, and Marina Baldi〈br〉 Adv. Sci. Res., 15, 257-262, https://doi.org/10.5194/asr-15-257-2019, 2019〈br〉 Recently, WMO and its Regional Training Centers engaged sustaining member Countries in developing Climate Services. Given its large spatio-temporal variability, Mediterranean is one of the most interseting regions for the application of Seasonal Forecasts. This paper presents a new educational approach, based on a blend of presencial and distance learning, culminated in the development of a course package where lerners can design their own learning path and that can be adapted to other regions.

Description: Twenty-first century wave climate projections for Ireland and surface winds in the North Atlantic Ocean Sarah Gallagher, Emily Gleeson, Roxana Tiron, Ray McGrath, and Frédéric Dias Adv. Sci. Res., 13, 75-80, doi:10.5194/asr-13-75-2016, 2016 As an island located in the North Atlantic Ocean with a highly energetic wave and wind climate, Ireland is uniquely placed in terms of its ocean renewable energy resource. The socio-economic importance of this resource makes it a priority to quantify how the wave and wind climate may change in the future. We examine how surface winds in the North Atlantic Ocean may change towards the end of this century due to global climate change, and how these changes may affect Ireland's wave climate.

Description: SATIN–Satellite driven nowcasting system Ingo Meirold-Mautner, Alexander Kann, and Florian Meier Adv. Sci. Res., 13, 27-35, doi:10.5194/asr-13-27-2016, 2016 In this study a precipitation nowcasting method is developed which relies on satellite products and automatic weather station data only. It thus omits ground based radar observations which are not readily available in large parts of the world. The system shows improved skill when compared to numerical weather prediction models for analysis and for lead times up to one hour. This type of nowcasting could be valuable in data sparse regions where radar observations are lacking or of poor quality.

Description: Representation of the grey zone of turbulence in the atmospheric boundary layer Rachel Honnert Adv. Sci. Res., 13, 63-67, doi:10.5194/asr-13-63-2016, 2016 Numerical weather prediction model forecasts at hectometric resolution are now possible. This range of scales is called the "grey zone of turbulence" as turbulence structures are neither mainly resolved nor entirely subgrid. Turbulence parametrizations have to be adapted, and the adaptations at these scales depend on the existing parametrizations at larger or smaller scales. This study explains the modifications in current Météo France models to the grey zone of turbulence.

Description: Improvement of Solar and Wind forecasting in southern Italy through a multi-model approach: preliminary results Elenio Avolio, Rosa Claudia Torcasio, Teresa Lo Feudo, Claudia Roberta Calidonna, Daniele Contini, and Stefano Federico Adv. Sci. Res., 13, 69-73, doi:10.5194/asr-13-69-2016, 2016 The improvement of the Solar and Wind short-term forecasting represents a critical goal for the weather prediction community and is of great importance for a better estimation of power production from solar and wind farms. In this work we analyze the performance of two deterministic models operational at ISAC-CNR for the prediction of short-wave irradiance and wind speed, at two experimental sites in southern Italy.

Description: Climate reference stations in Germany: Status, parallel measurements and homogeneity of temperature time series Frank Kaspar, Lisa Hannak, and Klaus-Jürgen Schreiber Adv. Sci. Res., 13, 163-171, doi:10.5194/asr-13-163-2016, 2016 Germany's national meteorological service (DWD) operates a network of so-called climate reference stations. At these stations parallel measurements are performed in order to allow the comparison of manual and automatic observations. We present an analysis of parallel measurements of temperature at 2 m height. It is shown that the automation of stations did not cause an artificial increase in the series of daily mean temperature. A bias occurs for maximum temperature in specific configurations.

Description: On the comparability of knowledge transfer activities – a case study at the German Baltic Sea Coast focusing regional climate services Insa Meinke Adv. Sci. Res., 14, 145-151, https://doi.org/10.5194/asr-14-145-2017, 2017 In this article the comparability of knowledge transfer activities is discussed by accounting for external impacts. It is shown that factors which are neither part of the knowledge transfer activity nor part of the participating institution may have significant impact on the potential usefulness of knowledge transfer activities. The results show that the comparability of knowledge transfer activities is limited and challenge the adequacy of quantitative measures in this context.

Description: Multimodel probabilistic prediction of 2 m-temperature anomalies on the monthly timescale Alfonso Ferrone, Daniele Mastrangelo, and Piero Malguzzi Adv. Sci. Res., 14, 123-129, https://doi.org/10.5194/asr-14-123-2017, 2017 The ensemble reforecasts of the CNR-ISAC and ECMWF forecasting systems, both participating to the S2S project, have been combined in a multimodel ensemble. Tercile probability predictions of wintertime 2 m temperature produced through logistic regression outperform the probability estimation based on the direct count of ensemble members, in terms of RPSS and reliability diagrams. Also, it is argued that the logistic regression would not yield further improvements if a larger dataset were used.

Description: Weather dependent estimation of continent-wide wind wower generation based on spatio-temporal clustering Bruno U. Schyska, António Couto, Lueder von Bremen, Ana Estanqueiro, and Detlev Heinemann Adv. Sci. Res., 14, 131-138, https://doi.org/10.5194/asr-14-131-2017, 2017 Europe is facing the challenge of increasing shares of energy from variable renewable sources. Furthermore, it is heading towards a fully integrated electricity market, i.e. a Europe-wide electricity system. The stable operation of this large-scale renewable power system requires detailed information on the amount of electricity being transmitted now and in the future. To estimate the actual amount of electricity, upscaling algorithms are applied. Those algorithms – until now – however, only exist for smaller regions (e.g. transmission zones and single wind farms). The aim of this study is to introduce a new approach to estimate Europe-wide wind power generation based on spatio-temporal clustering. We furthermore show that training the upscaling model for different prevailing weather situations allows to further reduce the number of reference sites without losing accuracy.

Description: Engaging students and teachers in meteorology and atmospheric sciences: the LaMMA activities Valentina Grasso, Giorgio Bartolini, Riccardo Benedetti, Giulio Betti, Valerio Capecchi, Bernardo Gozzini, Ramona Magno, Andrea Orlandi, Luca Rovai, Claudio Tei, Tommaso Torrigiani, and Federica Zabini Adv. Sci. Res., 14, 109-114, https://doi.org/10.5194/asr-14-109-2017, 2017 This paper presents the educational activities on meteorology carried out by LaMMA Consortium, official weather service for Tuscany. Since 2011 every year more than 1200 students come to visit LaMMA to follow one of the proposed modules. Students have also the opportunity to visit the LaMMA weather operations room and meet the forecasters. Furthermore, an educational module on climate change based on a participatory approach was proposed to more than 500 teachers in the last two years.

Description: Subseasonal-to-seasonal (S2S) forecasts with CNRM-CM: a case study on the July 2015 West-European heat wave Constantin Ardilouze, Lauriane Batté, and Michel Déqué Adv. Sci. Res., 14, 115-121, https://doi.org/10.5194/asr-14-115-2017, 2017 Was the July 2015 heat wave that struck Western Europe predictable more than 10 days ahead and to what extent? This article addresses the question by assessing forecasts from the CNRM-CM sub-seasonal forecast system. It is found that a warm anomaly was anticipated up to one month ahead despite the limited skill of the forecast system at such lead-time. The possible causes for this relative success are then discussed.

Description: LES study of microphysical variability bias in shallow cumulus Yefim Kogan Adv. Sci. Res., 14, 103-107, https://doi.org/10.5194/asr-14-103-2017, 2017 Exact description of cloud microphysical processes is essential for providing accurate weather forecasts. The paper evaluates errors of different methods to account for variability of cloud microphysical parameters, such as cloud water. rain water, and cloud drop concentration. It is found that neglecting cloud variability results in a substantial underestimate of rain development in the short run. Nevertheless the total effect on rain development in the long run may be uncertain due to the fac

Description: Long-range forecasts for the energy market – a case study Otto Hyvärinen, Antti Mäkelä, Matti Kämäräinen, and Hilppa Gregow Adv. Sci. Res., 14, 89-93, https://doi.org/10.5194/asr-14-89-2017, 2017 Finnish Meteorological Institute and Helen Ltd examined the feasibility of long-range forecasts (longer than two weeks) of temperature for needs of the energy sector in Helsinki, Finland. In this study, we examined the quality of Heating degree day (HDD) forecasts. As the forecasts we used UK Met Office seasonal forecasts. The long-range forecasts of monthly HDD showed some skill in Helsinki in winter 2015–2016, up to two months, especially if the very cold January is excluded.

Description: Seasonal co-variability of surface downwelling longwave radiation for the 1982–2009 period in the Arctic Mauro Boccolari and Flavio Parmiggiani Adv. Sci. Res., 14, 139-143, https://doi.org/10.5194/asr-14-139-2017, 2017 The paper investigates, for 28 years, the correlation between the longwave radiation to the surface (SDL) and the sea ice concentration (SIC) over the Arctic Ocean. One relevant result is the strong correlations of the SDL/SIC co-variability with some main NH climate oscillations patterns. This study can help to better understand the relationship between atmospheric and cryospheric variables. The paper is based on an intensive use of some climate data sets provided by EUMETSAT and NSIDC.

Description: Met Éireann high resolution reanalysis for Ireland Emily Gleeson, Eoin Whelan, and John Hanley Adv. Sci. Res., 14, 49-61, https://doi.org/10.5194/asr-14-49-2017, 2017 This paper is a summary of a very high resolution climate reanalysis carried out for a domain covering Ireland, using the HARMONIE-AROME numerical weather prediction model. Details of the simulations and set-up as well as a preliminary analysis of the main output variables are included in the study.