ALBERT

Beschreibung: The main objective of this study was evaluation and mapping of an average rate of phenological changes for example special plant s indicators as a result of climatic changes in Poland. Multi-year analysis clearly showed a tendency to earlier onset of spring events. The average advance of flowering/leafing was −1.4 days/decade and −2.4 days/1°C. Whereas the response of autumn phenophases was ambiguous. Phenological and climate data come from archives of the Institute of Meteorology and Water Management. Analysis covered the period of 1951–1992. The relation between temperature and date of phenophases was described with Pearson's linear regression model. Statistical significance of the model parameters was checked with Student's t-test at the following levels: 0.05, 0.01, and 0.001. The results were visualised on maps. ArcGIS 9.2 Geostatistical Analyst was used to examine the data and create prediction maps. Numerous tests were performed in order to find an appropriate method of spatial interpolation. Finally kriging was chosen as the most precise.

Beschreibung: Warning is a key issue to reduce flash floods impacts. But, despite many studies, local and national authorities still struggle to issue good flash floods warnings. We will argue that this failure results from a classical approach of warnings, based on a strict separation between the assessment world and the action world. We will go further than the previous criticisms (Pielke and Carbone, 2002) and show that forecasters, decision makers, emergency services and local population have quite similar practices during a flash-flood warning. Focusing on the use of meteorological information in the warning process, our case study shows that more research about the real practices of stakeholders would be another step towards integrated studies.

Beschreibung: At MeteoSwiss an integrated modelling system is used to simulate the dispersion of radioactive material in emergency situations. For the prediction of the atmospheric flow, the COSMO numerical weather prediction model is used. The model is run operationally at 6.6 and 2.2 km horizontal resolution, respectively and uses a 1.5 order turbulence closure with a prognostic equation for turbulent kinetic energy. Both versions of the COSMO model are coupled off-line with a Lagrangian particle dispersion model (LPDM). The aim of this study is to investigate the sensitivity of the dispersion model to different interfacing approaches between LPDM and the COSMO model. The diagnosed turbulence variables are validated on an ideal convective case and two measurement campaigns. Simulations of hypothetical pollutant releases show that the different interfacing approaches can lead to substantial changes in the forecasted concentrations.

Beschreibung: The Satelite Application Facility on Climate Monitoring has implemented a new processing environment for AVHRR-based climate monitoring products. AVHRR measurements from NOAA-17, NOAA-18 and MetOp-A are utilized to generate daily and monthly means of several cloud parameters for Europe and the Inner Arctic: Cloud fraction, cloud types, cloud phase, cloud top height, cloud optical thickness and cloud liquid water path.

Beschreibung: The COST ES0602 action provides a forum for benchmarking approaches and practices in data exchange and multi-model capabilities for chemical weather forecasting and near real-time information services in Europe. The action includes approximately 30 participants from 19 countries, and its duration is from 2007 to 2011 (http://www.chemicalweather.eu/). Major efforts have been dedicated in other actions and projects to the development of infrastructures for data flow. We have therefore aimed for collaboration with ongoing actions towards developing near real-time exchange of input data for air quality forecasting. We have collected information on the operational air quality forecasting models on a regional and continental scale in a structured form, and inter-compared and evaluated the physical and chemical structure of these models. We have also constructed a European chemical weather forecasting portal that includes links to most of the available chemical weather forecasting systems in Europe. The collaboration also includes the examination of the case studies that have been organized within COST-728, in order to inter-compare and evaluate the models against experimental data. We have also constructed an operational model forecasting ensemble. Data from a representative set of regional background stations have been selected, and the operational forecasts for this set of sites will be inter-compared and evaluated. The Action has investigated, analysed and reviewed existing chemical weather information systems and services, and will provide recommendations on best practices concerning the presentation and dissemination of chemical weather information towards the public and decision makers.

Beschreibung: Particularly in summer, thermal conditions in urban areas are influenced by solar radiation and human health can be strongly affected by the higher temperature regime increased by the Urban Heat Island effect (UHI). Many studies have been carried out to estimate the temperature distribution in urban areas and some of these use or are based on data collected by meteorological instruments placed within the cities. At microscale, temperature collected by sensors can be influenced by the underlying surface characteristics and the closeness to warm surfaces. The aim of this study is to investigate how different exposure to solar radiation can affect air temperature measurement in streets and gardens. The study was carried out on two different areas in Florence during summer 2007. Shielded air temperature sensors were placed in a street of a high density built-up area and in a green area. Each area was monitored by two sensors, sited in different solar radiation exposure: one in a sunny area and the other in a shaded one. A preliminary data analysis showed a difference in every site between the air temperature values collected by the two sensors especially from the morning to the afternoon. The relationship between air temperature differences and synoptic meteorological conditions were also analyzed. In conclusion, the solar radiation exposure of a monitoring station is an important parameter that must be considered both during the instruments siting and the analysis of data collected by sensors previously placed. The result of this study shows that during particular synoptic conditions, data collected by the two sensors of the same area can be different.

Beschreibung: We propose the height zi of the inversion in the vertical profile of potential temperature, on the top of a mixed layer or of a residual layer as a relevant parameter for retrieving information related to water vapour in the lower layers of the atmosphere, from currently available operational satellites information. We estimated zi using an algorithm where a set of threshold values in the vertical gradients of potential temperature are used to analyse the available profiles in order to find relevant inversions. Thresholds are derived from the subjective analysis of a set of high vertical resolution soundings from the coastal site of the Italian Meteorological Service of Pratica di Mare (WMO #16245, lat. 41.66° N, lon. 12.45° E). The sensitivity of the method to vertical sampling is tested comparing results obtained by applying the method to two sets of about 6500 raw and sampled radiosoundings during the period 2002–2008. Differences in average seasonal and six-hourly values of zi from the two datasets are found within the range 5–10%. The method was then applied to a larger set of soundings from coastal and continental Mediterranean sites collected in a standard archive. It was found that mean summer values of zi at coastal sites are lower than in winter, conversely to continental sites. Furthermore, values of zi found using the proposed algorithm show a systematically higher inversion if compared to height found using the Richardson Number method, although there are cases when both identify the inversion at the same height.

Beschreibung: During 2007-2009 the ADAGIO project (http://www.adagio-eu.org) is carried out to evaluate regional adaptation options in agriculture in most vulnerable European regions (mediterranean, central and eastern European regions). In this context a bottom-up approach is used beside the top-down approach of using scientific studies, involving regional experts and farmers in the evaluation of potential regional vulnerabilities and adaptation options. Preliminary results of the regional studies and gathered feedback from experts and farmers show in general that (increasing) drought and heat are the main factors having impact on agricultural vulnerability not only in the Mediterranean region, but also in the Central and southern Eastern European regions. Another important aspect is that the increasing risk of pest and diseases may play a more important role for agricultural vulnerability than assumed before, however, till now this field is only rarely investigated in Europe. Although dominating risks such as increasing drought and heat are similar in most regions, the vulnerabilities in the different regions are very much influenced by characteristics of the dominating agroecosystems and prevailing socio-economic conditions. This will be even be more significant for potential adaptation measures at the different levels, which have to reflect the regional conditions.

Beschreibung: Water management authorities need detailed information about each component of the hydrological balance. This document presents a method to estimate the evapotranspiration rate, initialized in order to obtain the reference crop evapotranspiration rate (ET0). By using an Optimal Interpolation (OI) scheme, the hourly observations of several meteorological variables, measured by a high-resolution local meteorological network, are interpolated over a regular grid. The analysed meteorological fields, containing detailed meteorological information, enter a model for turbulent heat fluxes estimation based on Monin-Obukhov surface layer similarity theory. The obtained ET0 fields are then post-processed and disseminated to the users.

Beschreibung: One year of continuous wind and turbulence measurements at three levels (5, 9 and 25 m) on a mast located in the suburb of the city of Turin were collected. Those recorded during April 2007 are analyzed and their main characteristics are presented and discussed. The analysis includes, at each level, mean, standard deviation, Skewness, Kurtosis for the 3-D wind components and sonic temperature. The integral time scales for the 3-D wind components are also computed and friction velocity and Monin-Obukhov length are determined as well. In particular, the wind standard deviation profiles as a function of stability are compared to the literature predictions for flat undisturbed terrain. It is found that, while the vertical component agrees reasonably well, the horizontal components deviate from the prescribed values, as expected considering the buildings and other obstacles effects and the high percentage of low-wind conditions. Also the integral time scales, estimated by the autocorrelation functions, are compared to the literature predictions, finding significant differences, again attributed to the low-wind speed occurrences.

Beschreibung: This work is devoted to the analysis of an unusual and sudden thermal fluctuation that interested portions of Friuli Venezia Giulia (Italy) during the night of 27 July 1983. The whole 1983 summer was extremely warm in Europe and in particular on the Italian peninsula, from the Alps down to Sicily. Nevertheless, the day of 27 July 1983 in Friuli Venezia Giulia deserves special attention because the observed maximum temperatures did not occur during day-time but during night-time (from 23:00 up to 24:00 LT, 21:00–22:00 UTC). Peaks of 34.8°C and values of relative humidity of the order of 28% were registered by the official network of weather stations. This event interested mainly the central-eastern part of the plain of Friuli Venezia Giulia, a few kilometers far from the Slovenian border and relieves. The thermal anomalies lasted up to an hour, then temperatures decreased toward values more usual for the climate of the month. The study of this event is carried out with the aid of the AR-WRF numerical atmospheric model, initialized through the ECMWF analysis. The numerical simulations highlight the important role played by orography, jointly with the peculiar thermal structure of the atmosphere, for the enhancing of the internal wave pattern over that area. According to the sensitivity studies realized, the amplification of the internal wave pattern might represent a possible explanation for that meteorological enigma.

Beschreibung: A three-dimensional air quality model based on a set of chemical species mass conservation equations describes the time evolution of chemical species in the atmosphere. In order to solve this set of equations, proper choices of initial and boundary conditions are needed. Ideally, initial and boundary conditions should be determined on the basis of observations. However, since such high-resolution observations are generally not available, it becomes necessary to use other information sources to specify the initial and boundary values. The fact that both the initial and the boundary conditions are specified with some degree of presumption makes it important to evaluate their influence in the model results. In this paper we present a study of the impact of initial and boundary concentrations on the modelled surface ozone concentration over two environments: Huelva and Badajoz, an industrial and a rural zone, respectively. The impacts are analysed for the same meteorological period (10–15 August 2003).

Beschreibung: When studying concentrations of particulate matter with a size of 10 µm or below (PM10), measured locally, it becomes evident that two main portions need to be quantified: The concentration produced by sources in the vicinity of the station and the long range transports. The traditional approaches include analyses of the components of PM10, comparisons upwind and downwind of a station, investigation of trajectories and complex chemical transport modelling. The development of an independent strategy which makes use of statistical methods, including regression and correlation analysis is a reasonable alternative. This method, presented here, does not apply the concept of PM10 sources, but, rather, analyzes the relations between times series of PM10 measurements and atmospheric properties. It is applied to identify the shares of the local portion and the large-scale background plus a stochastic portion that cannot be attributed to either of the two. Using regression analysis, a set of objectively chosen meteorological parameters is used to reconstruct the local PM10 measurement series, defining the local portion. This weather-dependent part of the series is then removed and the residuum, which contains the large-scale PM10 background and a stochastic portion is analyzed further with correlations. Results are shown for a three-year set of data which includes well over 250 PM10 stations across Germany. The data is analyzed according to different stratifications, such as the PM10 load and the wind direction as well as for the data set as a whole. In a further development of the method, a study of PM10 transports across several border sections is shown.

Beschreibung: Seven of the infrared channels from the Spinning Enhanced Visible and Infrared Imagery (SEVIRI) instrument, on board the Meteosat Second Generation (MSG), are used to retrieve Layer Precipitable Water (LPW) and Stability Analysis Imagery (SAI) in the SAFNWC framework. Both products are retrieved using a statistical retrieval based on neural networks; they are routinely generated every fifteen minutes at a satellite horizontal resolution of 3 km in NADIR only in cloud-free areas. Many factors are involved in the development of severe weather and these parameters are only some of the indicators. However, due to the high resolution of these products, the use of them in conjunction with satellite and radar images can help to identify mesoscale features related to convection. The MSG moisture and parcel instability time trend fields are especially useful during the period previous to convection. Once the outbreak of convection occurs, the products calculated in the clear air pixels surrounding the convective system can give us hints to anticipate its evolution. SAFNWC LPW and SAI were analyzed for a severe weather event during August 2004. A thunderstorm over Teruel (Spain) produced intense precipitation and hail; a tornado developed while this thunderstorm was moving towards SE. The pre-convective parcel potential buoyancy and moisture SAFNWC products changed in a way that was consistent with the observed intense convective activity. In previous studies, the atmospheric moisture in medium levels, which has been proven to be relevant in some cases, was represented by only one level parameter (ML: middle layer LPW). However, it was observed that this layer is too thick to do an adequate analysis of moisture available for convection. Hence, an improvement on the LPW algorithm has been carried out by splitting the middle layer into two new sub-layers (approximately separated at 700 hPa) and training two new neural networks. The impact of monitoring moisture in the new sub-layers separately in this severe weather event has been tested, and the improvements achieved have been evaluated.

Beschreibung: Heavy rain is one of the most important high-impact weather phenomena that occasionally affect Mediterranean areas. The aim of this study is to achieve a classification of atmospheric patterns related to heavy rain events in both French and Spanish Mediterranean regions. The classification is made on some atmospheric fields (geopotential at 1000 hPa and at 500 hPa and temperature at 850 hPa) of HIRLAM-INM-0.5° operational analysis, for heavy rain events included in the High Impact Weather MEDEX database. It covers a period of roughly 7 and a half years, from January 1997 to May 2004. A Principal Components Analysis was conducted to reduce the number of variables. After that, by means of a Cluster Analysis, the heavy rain events are classified into 8 atmospheric patterns. The results show a good relationship between regions affected by heavy rain and atmospheric patterns, in the sense that the same atmospheric patterns usually produce heavy rain in different regions, and heavy rain in different regions is usually due to specific atmospheric patterns.

Beschreibung: This study is embedded into a wider project named "Tackle deficiencies in Quantitative Precipitation Forecast (QPF)'' in the framework of the COSMO (COnsortium for Small-scale MOdelling) community. In fact QPF is an important purpose of a numerical weather prediction model, for forecasters and customers. Unfortunately, precipitation is also a very difficult parameter to forecast quantitatively. This priority project aims at looking into the COSMO Model deficiencies concerning QPF by running different numerical simulations of various events not correctly predicted by the model. In particular, this work refers to a severe event (moist convection) happened in Piemonte region during summer 2006. On one side the results suggest that details in orography representation have a strong influence on accuracy of QPF. On the other side COSMO Model exhibits a poor sensitivity on changes in numerical and physical settings when measured in terms of QPF improvements. The conclusions, although not too general, give some hint towards the behaviour of the COSMO Model in a typical convective situation.

Beschreibung: On 28–29 November 2005 an extratropical storm affected the Canary Islands causing significant damage related to high average wind speeds and intense gusts over some islands of the archipelago. Delta was the twenty-sixth tropical or subtropical storm of the 2005 Atlantic hurricane season. It represents an unusual meteorological phenomenon for that region, and its impacts were underestimated by the different operational meteorological forecasts during the previous days of the arrival of the low near Canary Islands. The aim of this study is to reproduce the local effects of the flow that were observed over the Canary Islands during the travel of the Delta storm near the region using high-resolution mesoscale meteorological simulations. The Advanced Research Weather Research & Forecasting Model (WRF-ARW) is applied at 9, 3 and 1 km horizontal resolution using ECMWF forecasts as initial and boundary conditions. The high-resolution simulation will outline the main features that contributed to the high wind speeds observed in the archipelago. Variations in vertical static stability, vertical windshear and the intense synoptic winds of the southwestern part of Delta with a warm core at 850 hPa were the main characteristics that contributed to the development and amplification of intense gravity waves while the large-scale flow interacted with the complex topography of the islands.

Beschreibung: The overall agricultural system in the Nile Delta region is considered as one of the highest intensive and complicated agriculture systems in the world. According to the recent studies, the Nile Delta region is one of the highly vulnerable regions in the world to climate change. Sea level rise, soil and water degradation, undiversified crop-pattern, yield reduction, pests and disease severity, and irrigation and drainage management were the main key factors that increased vulnerability of the agriculture sector in that region. The main objective of this study is to conduct a community-based multi-criteria adaptation assessment in the Nile Delta using a preset questionnaire. A list of possible adaptation measures for agriculture sector was evaluated. The results indicated that the Nile Delta growers have strong perceptions to act positively to reduce the impacts of climate change. They reflected the need to improve the their adaptive capacity based on clear scientific message with adequate governmental support to coop with the negative impacts of climate change.

Beschreibung: In recent years, the use of mesoscale meteorological network data has been growing. An Optimal Interpolation (OI) method is used to interpolate on a regular grid the hourly averaged values of temperature, relative humidity, wind vector, atmospheric pressure, and hourly cumulated precipitation. For all variables, except precipitation, the background (i.e. first guess) information is obtained by detrending the observations using the geographical parameters. For precipitation, the M. Lema radar-derived best estimate of precipitation rate at the ground is used. The characteristics of the OI schemes are shown in several test cases using data from ARPA Lombardia's mesoscale meteorological network. Finally, a quantitative diagnostics for temperature and relative humidity is carried out by using Cross Validation (CV) scores computed with large sets of data.

Beschreibung: Monthly Northern and Central Italy precipitation climatologies, obtained by means of a procedure aiming at capturing the local dependence of precipitation on elevation, are presented. The procedure consists in considering each cell of a high-resolution grid and in making use of the closest 15 stations in order to perform a weighted linear regression of precipitation versus elevation: the weights are determined by the distances of the stations from the grid point and by the level of similarity between the stations' cells and the considered grid cell in terms of elevation, slope steepness, slope orientation and distance from the sea. The study is based on a dataset of about 3200 1961–1990 monthly precipitation normals. The performance of the procedure is evaluated by reconstructing the monthly precipitation normals of each station and by comparing them with the corresponding observed values. Such comparisons are performed by means of five error estimators: the mean absolute error and the mean error, both evaluated in absolute and relative form, and the root mean squared error. The mean absolute error is slightly more than 10 mm for the monthly precipitation, which turns out to be between 10% and 14% of the monthly precipitation.

Beschreibung: EUROGRID is the vision of the European network of meteorological services (EUMETNET) about a European service for gridded climate monitoring information and products responding to the needs of users from a variety of domains. The EUMETNET project Showcase EUROGRID (S-EUROGRID) presented in this paper has the main objective to provide a better understanding of the EUROGRID idea and the way forward towards its realization. In addition to the identification of user requirements on gridded climate monitoring data and services S-EUROGRID aims to demonstrate example products and services building on existing shared gridded climate monitoring information available from European meteorological and hydrological services and other initiatives. The latter includes a harmonized visualization of data, the generation of example products/services and the dissemination of raw or processed data to the user community. For these purposes S-EUROGRID needed a simple and low-cost technical solution allowing for the seamless integration and dissemination of maps and data contributed by distributed resources, leading to Open Geospatial Consortium (OGC)-protocols as one promising option. In this concept, data providers can set up their own OGC-compliant services for climate data, which then can be viewed/accessed in a harmonized way, e.g. through the S-EUROGRID portal or by a user's specific client software (e.g. a GIS). Dynamic (i.e. real-time) generation of products is beyond the scope of S-EUROGRID, but the architectural choice of OGC-standards offers easy ways for client-side data processing, e.g., using the end user's GIS capacity. In addition, S-EUROGRID hosts a selection of pre-processed example products, illustrating the potential of combining gridded climate monitoring information with data and information sources from other thematic domains.

Beschreibung: The paper presents monthly 30-arc-second-resolution Northern and Central Italy temperature climatologies and discusses the procedure we adopt to superimpose the information of temperature secular records onto these climatologies. The climatologies are obtained by means of a step-wise linear regression method which aims at determining the temperature dependence on geographical and morphological variables. Such a method is applied to a database of about 800 monthly 1961–1990 temperature normals. In the first regression (temperature vs. elevation) the recorded data are considered; the further regressions concern the residuals obtained after taking into account the effect of each variable, in order of importance. An estimated secular anomaly record can be obtained for each point of the climatology grid by means of a distance-weighted average of the temperature anomaly records of the stations surrounding the grid point.

Beschreibung: The objective of this study is to present and analyse the spatial distribution of PM1 (particulate matter with diameter less than 1 μm) and PM10 (particulate matter with diameter less than 10 μm) within the greater area of Athens (GAA), Greece, during two extreme Saharan dust episodes in 2006 and 2008. Two portable detectors, based on light scattering method, were used to record the particulate matter concentrations. The samples were collected in the same morning hour of the day which coincided with the peak of vehicles traffic. We analysed the recorded data on normal days and on days with extreme Saharan dust events in order to find out the exceedances of the particulate matter concentrations. Using Kriging method, the spatial patterns of PM1 and PM10 concentrations were constructed for GAA. It is already known that particulate matter represent the main hazard in cardiovascular and respiratory syndromes within the most polluted cities of Europe, which confront high traffic problems, amplified by Saharan dust episodes, which are frequent especially in the Southern Europe, during spring time. The results of the performed analysis showed that during these episodes, PM concentrations over exceed the thresholds set by the European Union, exacerbating the human health in Athens.

Beschreibung: Modern supercomputers allow realising multi-scale systems for assessment and forecasting of urban meteorology, air pollution and emergency preparedness and considering nesting with obstacle-resolved models. A multi-scale modelling system with downscaling from regional to city-scale with the Environment – HIgh Resolution Limited Area Model (Enviro-HIRLAM) and to micro-scale with the obstacle-resolved Micro-scale Model for Urban Environment (M2UE) is suggested and demonstrated. The M2UE validation results versus the Mock Urban Setting Trial (MUST) experiment indicate satisfactory quality of the model. Necessary conditions for the choice of nested models, building descriptions, areas and resolutions of nested models are analysed. Two-way nesting (up- and down-scaling), when scale effects both directions (from the meso-scale on the micro-scale and from the micro-scale on the meso-scale), is also discussed.

Beschreibung: This project will provide the European Commission (EC) with an overview of the likely impacts of climate change on biodiversity in the European Union (EU), particularly within the Natura 2000 (N2K) network of protected areas, and indications of how the design and implementation of current policy might need to be adapted to ensure that the EU delivers its commitment to halt biodiversity loss by 2010 and beyond. The study will identify those species and associated habitats that are likely to be most vulnerable to climate change and the steps required to protect the integrity of the network from negative effects. The study will also assess the impacts of large-scale renewable energy schemes (wind parks, hydroelectric schemes and tidal barrages) on biodiversity and produce guidelines on the sorts of measures that might be used to maintain and protect N2K sites.

Beschreibung: The concentration fields calculated with three Gaussian models and one Lagrangian dispersion model are validated against a set of SF6 concentration data provided by the German environmental programme BWPLUS. The source was a pig fattening unit in fairly flat terrain. The results reveal that, in flat terrain with steady undisturbed flow, the use of Gauss models is still justified, whereas Lagrangian models should be used whenever the flow is modified by obstacles or topography.

Beschreibung: Scattering and absorption coefficients near the ground were measured in Évora, Portugal, in the period of 2006 to 2008. The average scattering coefficient, at the wavelength of 550 nm, for the whole period of measurements was found to be 40.3 Mm−1 and the absorption coefficient, at the wavelength of 670 nm, 8.6 Mm−1. These values are comparable to those measured in rural or background locations and reflect the small size of the city and relatively low magnitude of anthropogenic production at the site. A marked seasonal variation was found for the absorption coefficient, with a significant increase from 5.8 Mm−1, in summer, to 13.4 Mm−1, in winter. Regarding black carbon mass concentrations, this twofold increase, from 0.9 to 2.0 μgm−3, is mainly attributed to the wood combustion used for heating in conjunction with lower boundary layer mixing heights. The average scattering coefficient presented a more complex behaviour, although with a tendency for higher values in winter and lower values in spring.

Beschreibung: Quality control and homogenization has to be undertaken prior to any data analysis in order to eliminate any erroneous values and non climatic biases in time series. In this work we describe and then apply our own approach to data quality control, combining several methods: (i) by applying limits derived from interquartile ranges (ii) by analyzing difference series between candidate and neighbouring stations and (iii) by comparing the series values tested with "expected'' values – technical series created by means of statistical methods for spatial data (e.g. IDW, kriging). Because of the presence of noise in series, statistical homogeneity tests render results with some degree of uncertainty. In this work, the use of various statistical tests and reference series made it possible to increase considerably the number of homogeneity test results for each series and thus to assess homogeneity more reliably. Inhomogeneities were corrected on a daily scale. These methodological approaches are demonstrated by use of the daily data of air temperature and precipitation measured in the area of the Czech Republic. Series were processed by means of developed ProClimDB and AnClim software (http://www.climahom.eu).

Beschreibung: Vince was an unusual hurricane that developed over the North Atlantic Ocean in an unexpected area, on October 2005. In this work, the authors analyze its background and genesis over the ocean, making use of satellite imagery and numerical models. The impacts on sea state are investigated both numerically and observationally. Landfall over the Iberian Peninsula is monitored with surface observations and a radar system at Algarve (Portugal).

Beschreibung: Geographical Information Systems (GIS) can be used to integrate data from different sources and in different formats to perform innovative spatial and temporal analysis. GIS can be also applied for climatic research to manage, investigate and display all kinds of weather data. The main objective of this study is to demonstrate that GIS is a useful tool to examine and visualise precipitation distribution obtained from different data sources: ground measurements, satellite and radar data. Three selected days (30 cases) with convective rainfall situations were analysed. Firstly, scalable GRID-based approach was applied to store data from three different sources in comparable layout. Then, geoprocessing algorithm was created within ArcGIS 9.2 environment. The algorithm included: GRID definition, reclassification and raster algebra. All of the calculations and procedures were performed automatically. Finally, contingency tables and pie charts were created to show relationship between ground measurements and both satellite and radar derived data. The results were visualised on maps.

Beschreibung: The German Meteorological Service (Deutscher Wetterdienst) is presently developing a European climate information system (EuCLIS) which is presented here. The aim of this system is to distribute climate monitoring information of the area of the WMO (World Meteorological Organisation) Region VI (Europe and the Middle East) via the web. EuCLIS will be the successor of the already existing platform GCMP (Generate Climate Monitoring Products) which emerged from a project of the ECSN (European Climate Support Network). Climate monitoring information can be all kind of maps, diagrams and texts describing the variability of climate variables in space and time. It can be provided by the public national meteorological and hydrological services of all countries of the WMO Region VI. The main advantage is to have one common efficient climate monitoring distribution system for the whole Region, but the individual meteorological and hydrological services have the possibility to administrate their products on their own. EuCLIS considers the WMO metadata standard and modern web portal technology. In an advanced state, EuCLIS is intended to be used as a platform for a function of a Regional Climate Centre for Climate Monitoring which is currently planned at the WMO.

Beschreibung: The model PROCULTURE has been developed by the Université Catholique de Louvain – UCL (Belgium) to simulate the progress of the septoria leaf blotch disease on winter wheat during the cropping season. The model has been validated in Luxembourg for four years at four distinct representative sites. It is able to identify infection periods due to the causal agent Mycosphaerella graminicola on the last five leaf layers by combining meteorological data with phenological data from PROCULTURE's crop growth model component. The meteorological forcing consists of hourly time-series of air temperature, relative humidity and cumulative rainfall since the time of sowing, retrieved from automatic weather stations for hindcast and numerical weather prediction model outputs for the forecast periods. In order to improve the model, leaf wetness – which is one of the most important drivers for the spread of the disease – shall be added as an additional predictor. Therefore leaf wetness sensors were set up at four test sites during the 2007 growing season. To get a continuous spatial coverage of the country, it is planned to couple the PROCULTURE model offline to 12-hourly operational weather forecasts from an implementation of the Weather Research and Forecasting (WRF) model for Luxembourg at 1 km resolution. Because the WRF model does not provide leaf wetness directly, an artificial neural network (ANN) is used to model this parameter.

Beschreibung: The main objectives of this work are to analyze, firstly, the detail of the causes of a low ozone event which occurred in January 2006 and, secondly, the related effects of this anomalous episode on ultraviolet (UV) radiation measured at three locations in Extremadura (South-Western Spain). On 19 January 2006, the OMI total ozone column (TOC) was 16–20% below the January mean value of TOMS/NASA TOC (period 1996–2005). The back trajectories analysis with the HYSplit model indicates that the notable decrease of TOC could be attributed to a fast rise of the isentropic trajectories height. Concomitantly, UV erythemal radiation greatly increases (between 23% and 37%) on 19 January 2006 respect to UV erythemal radiation measured on 19 January 2005. This notable increase in winter UV solar radiation may involve harmful effects for organisms adapted to receive less radiation during that season (e.g. early developmental stages of terrestrial plants and phytoplankton).

Beschreibung: Throughout Europe the summer of 2003 was exceptionally warm, especially July and August. The European Environment Agency (EEA) reported several ozone episodes, mainly in the first half of August. These episodes were exceptionally long-lasting, spatially extensive, and associated to high temperatures. In this paper, the 10$ndash;15 August 2003 ozone pollution event has been analyzed using meteorological and regional air quality modelling. During this period the threshold values of the European Directive 2002/3/EC were exceeded in various areas of the Iberian Peninsula. The aim of this paper is to computationally understand and quantify the influence of biogenic volatile organic compound (BVOC) emissions in the formation of tropospheric ozone during this high ozone episode. Being able to differentiate how much ozone comes from biogenic emissions alone and how much comes from the interaction between anthropogenic and biogenic emissions would be helpful to develop a feasible and effective ozone control strategy. The impact on ozone formation was also studied in combination with various anthropogenic emission reduction strategies, i.e., when anthropogenic VOC emissions and/or NOx emissions are reduced. The results show a great dependency of the BVOC contribution to ozone formation on the antropoghenic reduction scenario. In rural areas, the impact due to a NOx and/or VOC reduction does not change the BVOC impact. Nevertheless, within big cities or industrial zones, a NOx reduction results in a decrease of the biogenic impact in ozone levels that can reach 85 μg/m3, whereas an Anthropogenic Volatile Organic Compound (AVOC) reduction results in a decrease of the BVOC contribution on ozone formation that varies from 0 to 30 μg/m3 with respect to the contribution at the same points in the 2003 base scenario. On the other hand, downwind of the big cities, a decrease in NOx produces a minor contribution of biogenic emissions and a decrease in AVOCs results in greater contributions of BVOCs to the formation of ozone.

Beschreibung: The climatic reference values for monthly and annual average air temperature and total precipitation in Catalonia – northeast of Spain – are calculated using a combination of statistical methods and geostatistical techniques of interpolation. In order to estimate the uncertainty of the method, the initial dataset is split into two parts that are, respectively, used for estimation and validation. The resulting maps are then used in the automatic outlier detection in meteorological datasets.

Beschreibung: COST – European COoperation in the field of Scientific and Technical Research – is the oldest and widest intergovernmental European network for cooperation in research. COST Action 725 (running from 2004 to 2009) aimed at and succeeded in establishing a European data base of phenological observations, classifying the data according to one common system and using the data in scientific peer reviewed papers. COST725 organized many workshops and conferences that helped to bring together not only the European, but also the global, phenological community. One of the highlights of COST725 was the boxed entry "Phenological responses to climate in Europe: the COST725 project" in the AR4 of IPCC in 2007. And last, but not least, although the action ended in April 2009 a follow up will be launched in 2010 under EUMETNET/ECSN.

Beschreibung: Almost every year, localised and in some cases more widespread floodings affect parts of Cyprus, causing damages to properties destruction to infrastructure and housing and sometimes the loss of human life. Various factors such as the meteorological situation and type and intensity of precipitation, the geomorphology, the geology and the human intervention to geomorphology are responsible for flood events. In the present study, only the meteorological situation and the associated mechanisms are examined in an attempt to gain the essential knowledge for improvement of local weather forecasts. The study period covers a thirteen-year period, from 1994 to 2006, in which 43 cases of flooding were reported, mainly over urbanized areas. The dominant favorable weather conditions for flood events are either the existence of a depression or weather conditions of convectional type. According to these two factors, the flood events were classified into two categories; the "instability'' category which includes isolated flood events of short duration, and the "depression'' category which includes widespread flood events of long duration.

Beschreibung: The strategy of new generation integrated Meso-Meteorological (MetM) and Atmospheric Chemical Transport (ACT) models for predicting atmospheric composition, meteorology and climate change is discussed for the Enviro-HIRLAM (HIgh Resolution Limited Area Model) integrated system. Current progress in the Enviro-HIRLAM system development and its urban on-line coupled modelling applications is considered. Results of several sensitivity studies of the urban effects (urban albedo and roughness, anthropogenic heat flux, heat island, and urban aerosols) on meteorology and air pollution at different scales are presented. Several sensitivity tests of the off-line versus on-line coupling of MetM and ACT models in Enviro-HIRLAM as well as their verification versus the ETEX experiment are considered and results are discussed.

Beschreibung: Computer-generated visualizations of geoscientific data, such as those from climate models are in high demand for a wide variety of usages; these include, among others, scientific publications, reports and graphical aides for the general public's improved understanding of complex developments. The paper will focus on the effects of colours in two-dimensional displays. Practical examples are given from which it becomes clear that considerable confusion or even damage can arise from an uninformed use of colour mapping and if results become, e.g., published in an unchecked manner by the media.

Beschreibung: The main objective of this work is to determine the parameters of hydrological balance for several basins in the prefecture of Korinthia (SE Greece), using hydrometeorological data and geographic information systems (GIS) technology. Multiple linear regression and GIS were used to estimate the spatial distribution of rainfall. The largest precipitation amounts occur in the SW part of the region and decrease towards the eastern and northern coastal parts. The long term mean annual rainfall is 1.39×109 m3. Based on the Thornthwaite method, infiltration and streamflow were estimated to be 0.29×109 m3/yr and 0.38×109 m3/yr, respectively. The unequal distribution of rainfall results in water surplus in the western part of Korinthia prefecture and water deficit in the eastern. We conclude that he estimation of hydrologic balance is a useful tool in order to establish sustainable water resources management in each hydrological basin.

Beschreibung: In November 2005 an extratropical storm named Delta affected the Canary Islands (Spain). The high sustained wind and intense gusts experienced caused significant damage. A numerical sensitivity study of Delta was conducted using the Weather Research & Forecasting Model (WRF-ARW). A total of 27 simulations were performed. Non-hydrostatic and hydrostatic experiments were designed taking into account physical parameterizations and geometrical factors (size and position of the outer domain, definition or not of nested grids, horizontal resolution and number of vertical levels). The Factor Separation Method was applied in order to identify the major model sensitivity parameters under this unusual meteorological situation. Results associated to percentage changes relatives to a control run simulation demonstrated that boundary layer and surface layer schemes, horizontal resolutions, hydrostaticity option and nesting grid activation were the model configuration parameters with the greatest impact on the 48 h maximum 10 m horizontal wind speed solution.

Beschreibung: The development and verification of a probabilistic forecast system for winter thunderstorms around Amsterdam Airport Schiphol is described. We have used Model Output Statistics (MOS) to develop the probabilistic forecast equations. The MOS system consists of 32 logistic regression equations, i.e. for two forecast periods (0–6 h and 6–12 h), four 90×80 km2 regions around Amsterdam Airport Schiphol, and four 6-h time periods. For the predictand quality-controlled Surveillance et Alerte Foudre par Interférométrie Radioélectrique (SAFIR) total lightning data were used. The potential predictors were calculated from postprocessed output of two numerical weather prediction (NWP) models – i.e. the High-Resolution Limited-Area Model (HIRLAM) and the European Centre for Medium-Range Weather Forecasts (ECMWF) model – and from an ensemble of advected lightning and radar data (0–6 h projections only). The predictors that are selected most often are the HIRLAM Boyden index, the square root of the ECMWF 3-h and 6-h convective precipitation sum, the HIRLAM convective available potential energy (CAPE) and two radar advection predictors. An objective verification was done, from which it can be concluded that the MOS system is skilful. The forecast system runs at the Royal Netherlands Meteorological Institute (KNMI) on an experimental basis, with the primary objective to warn aircraft pilots for potential aircraft induced lightning (AIL) risk during winter.

Beschreibung: Soil moisture and ozone deposition velocity under continental climate conditions were estimated using a newly developed algorithm. The relationship between soil moisture and deposition velocity was investigated and analysed. These results emphasize the importance of a sophisticated parameterization of soil moisture in surface-atmosphere interaction processes.

Beschreibung: The Caliope project funded by the Spanish Ministry of the Environment establishes an air quality forecasting system for Spain to increase the knowledge on transport and dynamics of pollutants in Spain, to assure the accomplishment of legislation and to inform the population about the levels of pollutants, topics in which the European Commission has shown a great concern. The present contribution describes the first quantitative verification study performed so far with two chemistry transport models (CMAQ and CHIMERE) for a reference year (2004) at medium spatial resolution (around 20×20 km for the Iberian Peninsula). Both models perform similarly in the case of ground-level ozone. The mean normalised gross error MNGE remains below 15–20% during summertime, when ozone episodes occur, outlining the good skills of the system concerning the forecasting of air quality in Spain. Furthermore, the ongoing developments of the system towards high resolution modelling (4×4 km for Spain, 12×12 km for Europe, 1 h temporal resolution) and the integration with observations within the Caliope umbrella are described.

Beschreibung: Piedmont region is located in North-Western Italy and is surrounded by the alpine chain and by the Appennines. The region is covered by a wide extension of forests, mainly in its mountain areas (the forests cover 36% of the regional territory). Forested areas are interested by wildfire events. In the period 1997–2005 Piedmont was interested by an average 387 forest fires per year, covering an average 1926 ha of forest per year. Meteorological conditions like long periods without precipitation contribute to create favourable conditions to forest fire development, while the fire propagation is made easier by the foehn winds, frequently interesting the region in winter and spring particularly. The meteorological danger index FWI (Fire Weather Index) was developed by Van Wagner (1987) for the Canadian Forestry Service, providing a complete description of the behaviour of the different forest components in response to the changing weather conditions. We applied the FWI to the Piedmont region on warning areas previously defined for fire management purposes. The meteorological data-set is based on the data of the very-dense non-GTS network of weather stations managed by Arpa Piemonte. The thresholds for the definition of a danger scenarios system were defined comparing historical FWI data with fires occurred on a 5 years period. The implementation of a prognostic FWI prediction system is planned for the early 2008, involving the use of good forecasts of weather parameters at the station locations obtained by the Multimodel SuperEnsemble post-processing technique.

Beschreibung: During the night between the 8 and 9 December 2006 the seawall of the Savona harbour (Liguria Region in north west of Italy) was overtopped by waves. In this work the "Savona flash sea storm" has been studied by analyzing the data recorded by meteo-marine observing stations and the data produced by high resolution meteo-marine numerical models. The data show that, due to the presence of a fast moving low pressure system, the event was characterized by a rapid transition and interaction between two different regimes of winds and related sea states. The results of the study suggest that the most damaging dynamics of the event could be correlated to a bi-modal structure of the wave spectrum. Based on this the authors suggest that a deeper study of the spectral structure of sea storms could lead to define new operational forecasting tools for the preventive evaluation of sea storms damaging potential.

Beschreibung: The paper presents an estimate of emission source influence on PM10 concentrations in Berlin. Particulate matter less than 10 μm in aerodynamic diameter (PM10) is a conglomerate of different chemical components related to distinct sources and physico-chemical processes in the atmosphere and lithosphere. Emission reduction thus has temporally and spatially varying effects on different scales. Urban PM10 concentrations are heavily influenced by long range transport (up to 70%) from remote source areas, whereas rural air pollution is strongly determined by urban emissions. By means of emission reduction scenario simulations with a chemistry-transport-model it has been found that on average two third of the urban background concentrations in Berlin are due to Berlin-specific emissions. This percentage varies strongly considering primary and secondary components: only about 5% of secondary PM10 concentrations are related to local emissions, while approximately 70% of primary concentrations stem from the urban sources. City related emissions influence homogenously the rural air-pollution concentrations, but with different ranges of influence.

Beschreibung: This study presents a catalogue of synoptic patterns of torrential rainfall in northeast of the Iberian Peninsula (IP). These circulation patterns were obtained by applying a T-mode Principal Component Analysis (PCA) to a daily data grid (NCEP/NCAR reanalysis) at sea level pressure (SLP). The analysis made use of 304 days which recorded 〉100 mm in one or more stations in provinces of Barcelona, Girona and Tarragona (coastland area of Catalonia) throughout the 1950–2005 period. The catalogue comprises 7 circulation patterns showing a great variety of atmospheric conditions and seasonal or monthly distribution. Likewise, we computed the mean index value of the Western Mediterranean Oscillation index (WeMOi) for the synoptic patterns obtained by averaging all days grouped in each pattern. The results showed a clear association between the negative values of this teleconnection index and torrential rainfall in northeast of the IP. We therefore put forward the WeMO as an essential tool for forecasting heavy rainfall in northeast of Spain.

Beschreibung: Numerical simulations of a tropical-like cyclone in southern Italy have been performed with two different modelling systems (BOLAM-MOLOCH and WRF) with the aim of discussing the role of the surface fluxes in the development of the vortex and evaluating their intensity during the mature stage of the cyclone. Although significant differences emerge in their intensity, both the modelling systems agree in showing that the surface fluxes are more important than the latent heat release associated with convection in the initial phase of the vortex lifecycle, while they are less relevant (although more intense) when the minimum assumes the characteristic of a tropical cyclone.

Beschreibung: In the frame of the WMO Global Atmosphere Watch Urban Research Meteorology and Environment programme (GURME), a system for forecasting air pollution episode potential in the Canary Islands has been developed. Meteorological parameters relevant to air quality (synoptic wind speed, wind direction, boundary layer height and temperature at 91 vertical levels) are obtained from the European Centre for Medium range Weather Forecasting (ECMWF) once a day for up to four days ahead. In addition, a model based on the analogue method utilising six years of historical meteorological and air quality data predicts the probability of SO2 concentration exceeding certain thresholds for a measurement station located in Santa Cruz de Tenerife. Meteorological forecasts are also provided from a high resolution (2 km) local area model (MM5) implemented for the Canary Islands domain. This simple system is able to forecast meteorological conditions which are favourable to the occurrence of pollution episodes for the forthcoming days.

Beschreibung: A k-means cluster analysis of 96 hour trajectories arriving in Southeast (SE) Spain at 3000, 1500 and 500 m for the 7-year period 2000–2006 has been performed to identify and describe the main flows arriving at the study area. The dependence of the aerosol size distribution on the air mass origin has been studied by using non-parametric statistics. There are statistically significant differences on aerosol size distribution and meteorological variables at surface level according to the identified clusters.

Beschreibung: Backtrajectory differences and clustering sensitivity to the meteorological input data are studied. Trajectories arriving in Southeast Spain (Elche), at 3000, 1500 and 500 m for the 7-year period 2000–2006 have been computed employing two widely used meteorological data sets: the NCEP/NCAR Reanalysis and the FNL data sets. Differences between trajectories grow linearly at least up to 48 h, showing faster growing after 72 h. A k-means cluster analysis performed on each set of trajectories shows differences in the identified clusters (main flows), partially because the number of clusters of each clustering solution differs for the trajectories arriving at 3000 and 1500 m. Trajectory membership to the identified flows is in general more sensitive to the input meteorological data than to the initial selection of cluster centroids.

Beschreibung: Some available processing algorithms used to calculate the aerosol optical depth from radiometric measurements were tested. The aim was to evaluate the associated uncertainties in polar regions due to the data processing, in order to adjust the methodology of the calculation and illustrate the importance of these error sources. The measurements were obtained during a sun photometer campaign in Ny-Ålesund within the framework of the POLAR-AOD project.

Beschreibung: This paper provides an over view of a new international network of researchers, stakeholders, and end-users of remote sensing tools that will benefit the water resources management community. It discusses the concept of solutions networks focusing on the WaterNet and it invites EGU teams to join the in the initial stages of our WaterNet network. The NASA Water cycle Solutions Network's goal is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend NASA research results to augment decision support tools and meet national and international needs. This paper seeks to invite EU scientific teams and water resource management teams to join our WaterNet Solutions Network.

Beschreibung: Many processes interact in a complex and highly non-linear way during the life cycle of fog, the turbulent transport being among them. Observations and analysis of turbulence are, then, fundamental to our understanding of the physical mechanisms involved with fog formation, evolution and dissipation. Data gathered by fast-response sonic anemometers are processed using wavelet methods in order to estimate turbulence parameters such as kinetic energy or fluxes during the successive stages of fog evolution.

Beschreibung: Analytical model of convection in a thick horizontal cloud layer with free upper and lower boundaries is constructed. The cloud layer is supposed to be subjected to the Coriolis force due to the cloud rotation, which is a typical condition for tornado formation. It is obtained that convection in such system can look as just one rotating cell in contrast to the usual many-cells Benard convection. The tornado-type vortex is different from spatially periodic convective cells because their amplitudes vanish with distance from the vortex axis. The lower boundary at this convection can substantially move out of the initially horizontal cloud layer forming a single vertical vortex with intense upward and downward flows. The results are also applicable to convection in water layer with negative temperature gradient.