bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing natural resource models using the object modeling system: feasibility and challenges
Authors: Ahuja L. R. , Ascough J. C. , David O.
Published: April 2010

Abstract. Current challenges in natural resource management have created demand for integrated, flexible, and easily parameterized hydrologic models. Most of these monolithic models are not modular, thus modifications (e.g., changes in process representation) require considerable time, effort, and expense. In this paper, the feasibility and challenges of using the Object Modeling System (OMS) for natural resource model development will be explored. The OMS is a Java-based modeling framework that facilitates simulation model development, evaluation, and deployment. In general, the OMS consists of a library of science, control, and database modules and a means to assemble the selected modules into an application-specific modeling package. The framework is supported by data dictionary, data retrieval, GIS, graphical visualization, and statistical analysis utility modules. Specific features of the OMS that will be discussed include: 1) how to reduce duplication of effort in natural resource modeling; 2) how to make natural resource models easier to build, apply, and evaluate; 3) how to facilitate long-term maintainability of existing and new natural resource models; and 4) how to improve the quality of natural resource model code and ensure credibility of model implementations. Examples of integrating a simple water balance model and a large monolithic model into the OMS will be presented.
Integrating water quality models in the High Level Architecture (HLA) environment
Authors: Lindenschmidt K.-E. , Hesser F. B. , Rode M.
Published: April 2010

Abstract. HLA (High Level Architecture) is a computer architecture for constructing distributed simulations. It facilitates interoperability among different simulations and simulation types and promotes reuse of simulation software modules. The core of the HLA is the Run-Time Infrastructure (RTI) that provides services to start and stop a simulation execution, to transfer data between interoperating simulations, to control the amount and routing of data that is passed, and to co-ordinate the passage of simulated time among the simulations. The authors are not aware of any HLA applications in the field of water resources management. The development of such a system is underway at the UFZ -Centre for Environmental Research, Germany, in which the simulations of a hydrodynamic model (DYNHYD), eutrophication model (EUTRO) and sediment and micro-pollutant transport model (TOXI) are interlinked and co-ordinated by the HLA RTI environment. This configuration enables extensions such as (i) "cross-model" uncertainty analysis with Monte Carlo Analysis: time synchronisation allows EUTRO and TOXI simulations to be made after each successive simulation time step in DYNHYD, (ii) information transfer from EUTRO to TOXI to compute organic carbon fractions of particulate matter in TOXI, (iii) information transfer from TOXI to EUTRO to compute extinction coefficients in EUTRO and (iv) feedback from water quality simulations to the hydrodynamic modeling.
An advanced approach for catchment delineation and water balance modelling within wetlands and floodplains
Authors: Krause S. , Bronstert A.
Published: April 2010

Abstract. Water balance of wetlands within lowland floodplains is strongly influenced by the temporally variable spatial extent of the interactions between groundwater and surface water. A robust algorithm will be introduced which makes it possible to delineate the interaction zone between the lowland river and the floodplain. This interaction zone is specified as the "Direct Catchment" which is defined by the part of the connected floodplain in which wetland water balance is mainly affected by the surface water dynamics of the adjacent river. The delineation algorithm is based on transfer functions which were assessed by local simulation results of the integrated water balance and nutrient dynamics model IWAN. The transfer functions are further determined by mean annual groundwater depths and by simulated groundwater dynamics. They are controlled by simulation results of the maximal transversal extent of surface water influence on groundwater stages. The regionalisation of the developed delineation algorithm leads to the specification of the maximal extent of groundwater - surface water - interaction processes along the river. By application of this approach to the Havel River basin, located within lowlands of Northeaster Germany, it was possible to specify a 998.1 km2 part of the floodplain which is directly connected with the surface waters and thus called the "Direct Catchment" of the Havel river. The IWAN model was applied to simulate the water balance of the floodplain. The simulation results prove the tight interaction between river and floodplain. It is shown that the spatially and temporally variable influences of the connected floodplain on the river discharge were only important during low discharge in summer.
Airborne laser scanning and usefulness for hydrological models
Authors: Hollaus M. , Wagner W. , Kraus K.
Published: April 2010

Abstract. Digital terrain models form the basis for distributed hydrologic models as well as for two-dimensional hydraulic river flood models. The technique used for generating high accuracy digital terrain models has shifted from stereoscopic aerial-photography to airborne laser scanning during the last years. Since the disastrous floods 2002 in Austria, large airborne laser-scanning flight campaigns have been carried out for several river basins. Additionally to the topographic information, laser scanner data offer also the possibility to estimate object heights (vegetation, buildings). Detailed land cover maps can be derived in conjunction with the complementary information provided by high-resolution colour-infrared orthophotos. As already shown in several studies, the potential of airborne laser scanning to provide data for hydrologic/hydraulic applications is high. These studies were mostly constraint to small test sites. To overcome this spatial limitation, the current paper summarises the experiences to process airborne laser scanner data for large mountainous regions, thereby demonstrating the applicability of this technique in real-world hydrological applications.
Regional effects of ENSO in Central/Eastern Europe
Authors: Bartholy J. , Pongrácz R.
Published: April 2010

Abstract. El Niño - Southern Oscillation (ENSO) effects on the European circulation features and on the regional climate of Hungary are evaluated in this paper. European climate is represented by atmospheric macrocirculation patterns (MCPs). Local climate characteristics are linked to ENSO phases through regionally averaged temperature values and precipitation amounts. Significant statistical relationship was found between the European circulation and the ENSO phases. Furthermore, considerable differences were detected in the empirical frequency distribution of monthly climate anomalies in Hungary during El Niño and La Niña episodes.
The relationship between ENSO and Paraná River flow
Authors: Cardoso A. O. , Silva Dias P. L.
Published: April 2010

Abstract. Several studies indicate that there is a relationship between the climatic variability in the South American continent and alterations of the position and intensity of the heat sources in the equatorial region. The El Niño phenomenon can influence the precipitation over some regions of South America such as the Brazilian Northeast, Amazonia, South of Brazil and Uruguay. Over 80% of Brazil's energy comes from hydropower, and decisions concerning future availability and pricing require forecasts of river flow, ideally several months in advance. In this work the relationship between the Paraná River flow and the ENSO (El Niño/Southern Oscillation) mode is investigated and statistical forecasts of river flow are tested. An evaluation of the relationship between the Pacific sea surface temperature and the Paraná River flow indicates an ENSO pattern over the equatorial Pacific. The time series of the ENSO mode obtained by applying principal components analysis on the sea surface temperature (SST) were used as predictors for the Paraná River flow forecast. Improvement in the model forecast skill is also obtained by considering the lagged river flow time series as a predictor.
ENSO and interdecadal climate variability over the last century documented by geochemical records of two coral cores from the South West Pacific
Authors: Ourbak T. , Corrège T. , Malaizé B. , Le Cornec F. , Charlier K. , Peypouquet J. P.
Published: April 2010

Abstract. The south west Pacific is affected by climatic phenomena such as ENSO (El Niño Southern Oscillation) or the PDO (Pacific Decadal Oscillation). Near-monthly resolution calibrations of Sr/Ca, U/Ca and δ18Oc were made on corals taken from New Caledonia and Wallis Island. These geochemical variations could be linked to SST (sea surface temperature) and SSS (sea surface salinity) variations over the last two decades, itselves dependent on ENSO occurrences. On the other hand, near-half-yearly resolution over the last century smoothes seasonal and interannual climate signals, but emphasizes low frequency climate variability.
The 1997 El Niño impact on clouds, water vapour, aerosols and reactive trace gases in the troposphere, as measured by the Global Ozone Monitoring Experiment
Authors: Loyola D. , Valks P. , Ruppert T. , Richter A. , Wagner T. , Thomas W. , van der A R. , Meisner R.
Published: April 2010

Abstract. The El Niño event of 1997/1998 caused dry conditions over the Indonesian area that were followed by large scale forest and savannah fires over Kalimantan, Sumatra, Java, and parts of Irian Jaya. Biomass burning was most intense between August and October 1997, and large amounts of ozone precursors, such as nitrogen oxides, carbon monoxide and hydrocarbons were emitted into the atmosphere. In this work, we use satellite measurements from the Global Ozone Monitoring Experiment (GOME) sensor to study the teleconnections between the El Niño event of 1997 and the Indonesian fires, clouds, water vapour, aerosols and reactive trace gases (nitrogen dioxide, formaldehyde and ozone) in the troposphere.
ENSO effects on primary productivity in Southern Atacama desert
Authors: Squeo F. A. , Tracol Y. , López D. , Gutiérrez J. R. , Cordova A. M. , Ehleringer J. R.
Published: April 2010

Abstract. In the winter-rain southern Atacama Desert of the Coquimbo Region of Chile, El Niño - Southern Oscillation (ENSO) events modulate primary productivity. In this region, there are important changes in water availability between La Niña (dry) and El Niño (rainy) years. Using inter-annual comparisons of LANDSAT images from 30° to 31° S latitude, we observed changes in primary productivity between dry and rainy years at the regional level. There were also significant, negative correlations between productivity and elevation, with changes occurring first at low elevation during rainy years. The limiting factors to dryland vegetation primary productivity is different in regard to elevation. Rain during an El Niño year is the main factor that explains the increase in primary productivity at low elevation, while lower temperatures reduce and delay the net primary productivity at mid elevation.
El Niño effects on rainfall in South America: comparison with rainfalls in india and other parts of the world
Authors: Kane R. P.
Published: April 2010

Abstract. As a finer classification of El Niños, ENSOW were defined as years when El Niño (EN) existed on the Peru coast, Southern Oscillation Index SOI (Tahiti minus Darwin pressure) was negative (SO), and Pacific SST anomalies were positive (W). Further, Unambiguous ENSOW were defined as years when SO and W occurred in the middle of the calendar year, while Ambiguous ENSOW were defined as years when SO and W occurred in the earlier or later part of the calendar year (not in the middle). In contrast with India and some other regions where Unambiguous ENSOW were associated predominantly with droughts, in the case of South America, the association was mixed. In Chile on the western coast and Uruguay etc. on the eastern coast, the major effect was of excessive rains. In Argentina and central Brazil, the effects were unclear. In Amazon, the effects were not at all uniform, and were different (droughts or excess rains) or even absent in regions only a few hundred kilometers away from each other. Even in Peru-Ecuador, the effects were clear only in the coastal regions. In the interior and in the Andes, the effects were obscure. In NE Brazil, El Niños have been popularly known to be causing severe droughts. The fact is that during 1871–1998, there were 52 El Niño events, out of which 31 were associated with droughts in NE Brazil, while 21 had no association. The reason is that besides El Niños, another major factor affecting NE Brazil is the influx of moisture from the Atlantic. In some years, warmer Atlantic in conjunction with westward winds can bring moisture to NE Brazil, nullifying the drought effects of El Niños. A curious feature at almost all locations is the occurrence of extreme events (high floods or severe droughts) in some years, apparently without any El Niño or La Niña events. This possibility should always be borne in mind.
A synthesis of ENSO effects on drylands in Australia, North America and South America
Authors: Holmgren M. , Stapp P. , Dickman C. R. , Gracia C. , Graham S. , Gutiérrez J. R. , Hice C. , Jaksic F. , Kelt D. A. , Letnic M. , Lima M. , López B. C. , Meserve P. L. , Milstead W. B. , Polis G. A. , Previtali M. A. , Richter M. , Sabaté S. , Squeo F. A.
Published: April 2010

Abstract. Fundamentally, El Niño Southern Oscillation (ENSO) is a climatic and oceanographic phenomenon, but it has profound effects on terrestrial ecosystems. Although the ecological effects of ENSO are becoming increasingly known from a wide range of terrestrial ecosystems (Holmgren et al., 2001), their impacts have been more intensively studied in arid and semiarid systems. In this brief communication, we summarize the main conclusions of a recent symposium on the effects of ENSO in these ecosystems, which was convened as part of the First Alexander von Humboldt International Conference on the El Niño Phenomenon and its Global Impact, in Guayaquil, Ecuador, from 16–20 May 2005. Participants in the symposium shared results and perspectives from research conducted in North and South America and Australia, regions where the ecological effects of ENSO have been studied in depth. Although the reports covered a wide array of organisms and ecological systems (Fig. 1), a recurring theme was the strong increase in rainfall associated with ENSO events in dry ecosystems (during the El Niño phase of the oscillation in the Americas and the La Niña phase in Australia). Because inter-annual variability in precipitation is such a strong determinant of productivity in arid and semiarid ecosystems, increased ENSO rainfall is crucial for plant recruitment, productivity and diversity in these ecosystems. Several long-term studies show that this pulse in primary productivity causes a subsequent increase in herbivores, followed by an increase in carnivores, with consequences for changes in ecosystem structure and functioning that can be quite complex.
Synoptic environment related to rapid cyclogenesis in the Eastern Mediterranean
Authors: Lagouvardos K. , Kotroni V. , Defer E.
Published: April 2010

Abstract. This paper presents first results on the investigation of the synoptic conditions that led to the rapid development of a low-pressure system over the Aegean Sea. Indeed, during the period 21–22 January 2004, a very deep cyclone was observed over the Aegean Sea with a minimum central pressure of ~972 hPa, a value which is among the lowest observed over the entire Mediterranean Sea during the last 40 years. The rapid development was associated with a two-trough system that, under the influence of a very intense upper-level jet, was merged in one and then acquired a negative tilting. Additional information on the mesoscale organisation of the system is given, based on lightning data and space borne microwave and infrared observations.
Kinematic characteristics of hailstorms in Northern Greece
Authors: Foris D. V. , Karacostas T. S. , Flocas A. A. , Makrogiannis T. I.
Published: April 2010

Abstract. The purpose of this study is the analysis of radar data, digitally recorded, during an operational hail suppression program in the region of Central Macedonia, Greece, for the warm period of the years 1997–2001. Kinematic characteristics, such as lifetime and distance traveled by hailstorms, as well as direction of motion and speed, have been related to type of storms and season. It has been found that singlecells are short-lived and travel short distances, while multicells are long-lived and travel long distances. On the contrary, their corresponding speed distributions are similar. The deviation of the direction of motion from mean wind is smaller for singlecells than for multicells. September and July exhibit the maximum and minimum average storm speeds as a direct implication of synoptic disturbances passage and convection, prevailing respectively. Finally, storms overcoming orographic barriers decelerate in general on the windward side and accelerate on the lee side of mountains.
Warm season precipitation climatology: first European results
Authors: Levizzani V. , Ginnetti R. , Laing A. G. , Carbone R. E.
Published: April 2010

Abstract. To date very low scores are associated to quantitative precipitation forecasts (QPF) of warm season precipitation, a fact mostly due to the little knowledge of the mechanisms driving these phenomena. The study aims to produce a five-year climatology (1999–2003) of warm season precipitation systems (MJJA) over Europe using Meteosat IR brightness temperatures as a contribution to a global study launched by the World Weather Research Programme (WWRP). Cold cloud persistence, span and duration of weather systems were determined to derive the zonal propagation speed and daily cycles.
Preliminary verification results of the DWD limited area model LME and evaluation of its storm forecasting skill over the area of Cyprus
Authors: Orphanou A. , Michaelides S. , Savvidou K. , Constantinides P. , Schulz J.-P. , Voigt U.
Published: April 2010

Abstract. A preliminary verification and evaluation is made of the forecast fields of the non-hydrostatic limited area model LME of the German Weather Service (DWD), for a recent three month period. For this purpose, observations from two synoptic stations in Cyprus are utilized. In addition, days with depressions over the area were selected in order to evaluate the model's forecast skill in storm forecasting.
Synoptic and dynamic characteristics of selected deep depressions over Cyprus
Authors: Nicolaides K. A. , Michalelides S. C. , Karacostas T.
Published: April 2010

Abstract. In this study, the spatial and temporal distributions of dynamic and synoptic characteristics of a selection of 32 deep baroclinic depressions have been investigated. The study covers the cold period months of November till March, in the period from 1 November 1986 to 31 March 2003. For the needs of the study, several synoptic characteristics of these depressions have been extracted. Also, several dynamic characteristics during the evolution of the depressions were studied: relative vorticity, divergence, vertical motion and a static stability parameter. The results are presented in the form of isobaric distributions over, three tropospheric isobaric levels, namely the lower 850 hPa, the middle 500 hPa and the upper 300 hPa.
Quantifying the discharge forecast uncertainty by different approaches to probabilistic quantitative precipitation forecast
Authors: Diomede T. , Marsigli C. , Nerozzi F. , Paccagnella T. , Montani A.
Published: April 2010

Abstract. A probabilistic approach to flood prediction over the Reno river basin, a medium-sized catchment in Northern Italy, has been tested using two different meteorological ensemble systems. The future precipitation scenarios are provided either by an analogue-based technique (statistical approach) or by a limited-area ensemble prediction system (dynamical approach), then used as different inputs to a distributed rainfall-runoff model. The ensemble of possible future flows so generated allows to convey a quantification of uncertainty about the discharge forecast. The probabilistic discharge forecasts, based on the precipitation forecast provided by the two ensembles, are then compared to the deterministic one obtained by the rainfall-runoff model fed on precipitation input provided by a non-hydrostatic meteorological model, run at 7km of horizontal resolution. For this case study, the dynamical approach appears to be more feasible in providing useful discharge ensemble forecast than the statistical one, because the observed large spread among members obtained with the analogue method makes difficult to issue real-time flood warnings.
Evaluation of radiative transfer schemes for mesoscale model data assimilation: a case study
Authors: Memmo A. , Faccani C , Ferretti R. , Di Michele S. , Marzano F. S.
Published: April 2010

Abstract. The assimilation of Special Sensor Microwave Imager (SSM/I) data into the Mesoscale Model 5 (MM5) allows for improving the weather forecast. However the results suggested an update the Radiative Transfer Equation (RTE) within the three-dimensional variational (3DVAR) algorithm which is tailored for non rainy conditions only. To this purpose, a new RTE algorithm is tested, in order to account for radiometric response in rainy regions. The new brightness temperatures (TB) are estimated by using hydrometeor profiles from the MM5 mesoscale model, running with two different microphysical parameterizations. The goodness of the results is assessed by comparing the new TB with those of the original RTE algorithm in the 3DVAR code and the SSM/I observed data. The results confirm a better reliability of the new RTE compared to the old one.
The effect of the boundary conditions on the simulation of the 4 November 1966 storm over Italy
Authors: De Zolt S. , Lionello P. , Malguzzi P. , Nuhu A. , Tomasin A.
Published: April 2010

Abstract. This study analyses the extreme event which took place on 4 November 1966, when a storm produced intense and persistent precipitation over northern and central Italy and an extreme surge in the northern Adriatic Sea, causing casualties and huge damages. Numerical simulations with a regional atmospheric model have been performed to reconstruct the phenomenology of the event. Results have been compared with observations. This study shows that the choice of the global fields for initial and boundary conditions is crucial for the quality of the reconstruction. The simulation is reasonably accurate if they are extracted from the NCEP re-analysis, while it is not satisfactory if ERA-40 data are used, though fields have a higher resolution in the ERA-40 than in the NCEP set of data. The internal physics of the model plays a smaller role in the reproduction of the dynamics of the event.
Objective evaluation of mesoscale simulations of the Algiers 2001 flash flood by the model-to-satellite approach
Authors: Söhne N. , Chaboureau J.-P. , Argence S. , Lambert D. , Richard E.
Published: April 2010

Abstract. An objective evaluation of mesoscale simulations by the model-to-satellite approach is performed. The model-to-satellite approach consists in calculating brightness temperatures (BT) from model variables with a radiative transfer code. It allows to compare directly and quantitatively simulations and observations by calculating statistical scores. This method is detailed and used herein to objectively evaluate an ensemble of Meso-NH simulations of the Algiers 2001 flash flood. In particular, the improvement due to the grid-nesting is shown.
Advances in the WRF model for convection-resolving forecasting
Authors: Klemp J. B.
Published: April 2010

Abstract. The Weather Research and Forecasting (WRF) Model has been designed to be an efficient and flexible simulation system for use across a broad range of weather-forecast and idealized-research applications. Of particular interest is the use of WRF in nonhydrostatic applications in which moist-convective processes are treated explicitly, thereby avoiding the ambiguities of cumulus parameterization. To evaluate the capabilities of WRF for convection-resolving applications, real-time forecasting experiments have been conducted with 4 km horizontal mesh spacing for both convective systems in the central U.S. and for hurricanes approaching landfall in the southeastern U.S. These forecasts demonstrate a good potential for improving the forecast accuracy of the timing and location of these systems, as well as providing more detailed information on their structure and evolution that is not available in current coarser resolution operational forecast models.
Mediterranean offshore extreme wind analysis from the 44-year HIPOCAS database: different approaches towards the estimation of return periods and levels of extreme values
Authors: Sotillo M. G. , Aznar R. , Valero F.
Published: April 2010

Abstract. The present contribution addresses the performance of a statistical extreme wind analysis over the whole Mediterranean Basin. Estimations of return periods and levels are obtained over offshore areas through analysis of annual wind maxima. An alternative regional statistic method, based on regional L-moments, is also proposed. This regional technique allows increasing the sample size, using data from a homogeneous region instead of only from a single location, reducing therefore uncertainty. The performed statistical extreme wind analyses provide a detailed assessment of Mediterranean offshore high wind areas.
MTG: resolution enhancement for MW measurements from geostationary orbits
Authors: Dietrich S. , Di Paola F. , Bizzarri B.
Published: April 2010

Abstract. The purpose of this study is to develop and evaluate image processing techniques that improve the spatial resolution of the channels already selected in the preliminary studies for "Geostationary Observatory for Microwave Atmospheric Soundings (GOMAS)". Reference high resolution multifrequency brightness temperatures scenarios have been derived by applying radiative transfer calculation to the spatially and microphysically detailed output of meteorological events simulated by the University of Wisconsin - Non-hydrostatic Model System. Two approaches, Wiener filter and SIR algorithm, have been applied to low frequency channels to enhance the resolution of antenna temperatures, exploiting the oversampling available for GOMAS channels observational strategy. Quite similar improvements have been obtained by applying the two techniques, even if SIR algorithm has provided generally better performances at computation time's expense.
Performance of a rain retrieval algorithm using TRMM data in the Eastern Mediterranean
Authors: Katsanos D. , Viltard N. , Lagouvardos K. , Kotroni V.
Published: April 2010

Abstract. This study aims to make a regional characterization of the performance of the rain retrieval algorithm BRAIN. This algorithm estimates the rain rate from brightness temperatures measured by the TRMM Microwave Imager (TMI) onboard the TRMM satellite. In this stage of the study, a comparison between the rain estimated from Precipitation Radar (PR) onboard TRMM (2A25 version 5) and the rain retrieved by the BRAIN algorithm is presented, for about 30 satellite overpasses over the Central and Eastern Mediterranean during the period October 2003–March 2004, in order to assess the behavior of the algorithm in the Eastern Mediterranean region. BRAIN was built and tested using PR rain estimates distributed randomly over the whole TRMM sampling region. Characterization of the differences between PR and BRAIN over a specific region is thus interesting because it might show some local trend for one or the other of the instrument. The checking of BRAIN results against the PR rain-estimate appears to be consistent with former results i.e. a somewhat marked discrepancy for the highest rain rates. This difference arises from a known problem that affect rain retrieval based on passive microwave radiometers measurements, but some of the higher radar rain rates could also be questioned. As an independent test, a good correlation between the rain retrieved by BRAIN and lighting data (obtained by the UK Met. Office long range detection system) is also emphasized in the paper.
A case of severe flood over Albania: a rainfall analysis from a satellite perspective
Authors: De Luque A. , Porja T. , Martín A. , Guijarro J. A. , Alonso S.
Published: April 2010

Abstract. This paper presents results of daily rainfall estimates for the flood event in Albania occurred during the end of September 2002 (from the 21 until the 23). Estimated precipitations based on Meteosat-7 data and computed using various techniques, are compared with surface based observations. The two techniques, developed for convective clouds, were employed to screen the Albanian Flood. On one hand a single Infrared band technique known as Auto-estimator and on the other hand a three-channel Convective Rainfall Rate technique known as CRR. Secondly, for both methods, a number of corrections, such as, moisture, cloud growth rate, cloud top temperature gradient, parallax and orographic corrections were, also, performed and tested during the flood case. Preliminary results show that auto-estimator over-measure significantly daily rainfall with respect to the observed while CRR gives much closer rain quantities. The Auto-estimator power law curve was adjusted to the specific conditions using all the available rain rate gauge measurements. Satellite daily rainfall estimated by the two methods, corrected and calibrated were finally evaluated using the Albanian rain gauge network as ground true.
Heavy rain and strong wind events and cyclones in the Balearics
Authors: Campins J. , Jansà A. , Genovés A.
Published: April 2010

Abstract. The relationship between heavy rain (HR) and/or strong wind (SW) events and cyclones is investigated for the Balearic Islands. First, a list of HR and SW events is cross-referenced with an objective cyclone database for a 9-year period (from June 1995 to May 2004). The presence of a cyclone centre close to the Balearics is looked for each event. For HR events in most of the cases a cyclone centre is located in the vicinity. Furthermore, cyclones are located in such a way that allow the supply of warm and wet air to the affected area. But for SW events, although in the majority of cases a cyclone centre is detected, cyclones are located farther than for HR events and their geographical location is more widespread. Afterwards, the three-dimensional structure of cyclones related to HR and/or SW events is studied in detail.
Extreme precipitation events in NW Greece
Authors: Houssos E. E. , Bartzokas A.
Published: April 2010

Abstract. In this work, the extreme precipitation events in NW Greece are studied. The data used are daily precipitation totals recorded at the meteorological station of Ioannina University for the period 1970–2002. 156 days with precipitation totals above 35 mm (5% upper limit) are only considered. It is seen that, a minimum frequency of extreme precipitation events appears in the period 1986–1991, which is characterized by a high positive NAO index. For each of the 156 extreme precipitation days, at first, the mean sea level pressure pattern over Europe is constructed by using 273 grid point values. Using Factor Analysis, the dimensionality of the 156×273 data matrix is reduced to 156×5 (84% of the total variance) and then, Cluster Analysis is applied on the results of Factor Analysis. Thus, the 156 cases are grouped objectively to 11 clusters, revealing the main pressure patterns, which favour extreme precipitation in NW Greece. Seven of the patterns are encountered in winter and autumn, while three of them cover a period from autumn to spring and one appears mainly in summer. In all of them the cause of the extreme precipitation event is a low pressure system centred west of Greece or a low pressure trough extended eastwards or southwards up to Greece. In some cases the depression is so strong and extended that it covers the whole Europe and the Mediterranean. In the single summer pattern, rainfall is caused by an extension of the SW Asia thermal low up to the central Mediterranean.
Changing teaching techniques and adapting new technologies to improve student learning in an introductory meteorology and climate course
Authors: Cutrim E. M. , Rudge D. , Kits K. , Mitchell J. , Nogueira R.
Published: April 2010

Abstract. Responding to the call for reform in science education, changes were made in an introductory meteorology and climate course offered at a large public university. These changes were a part of a larger project aimed at deepening and extending a program of science content courses that model effective teaching strategies for prospective middle school science teachers. Therefore, revisions were made to address misconceptions about meteorological phenomena, foster deeper understanding of key concepts, encourage engagement with the text, and promote inquiry-based learning. Techniques introduced include: use of a flash cards, student reflection questionnaires, writing assignments, and interactive discussions on weather and forecast data using computer technology such as Integrated Data Viewer (IDV). The revision process is described in a case study format. Preliminary results (self-reflection by the instructor, surveys of student opinion, and measurements of student achievement), suggest student learning has been positively influenced. This study is supported by three grants: NSF grant No. 0202923, the Unidata Equipment Award, and the Lucia Harrison Endowment Fund.
Training programme for the dissemination of climatological and meteorological applications using GIS technology
Authors: De Filippis T. , Di Vecchia A. , Maracchi G. , Sorani F.
Published: April 2010

Abstract. IBIMET-CNR is involved in making different research projects and in managing operational programmes on national and international level and has acquired a relevant training competence to sustain partner countries and improve their methodological and operational skills by using innovative tools, such as Geographical Information Systems focused on the development of meteorological and climatological applications. Training activities are mainly addressed to National Meteorological and Hydrological Services of Partner-Countries and/or to other Specialized Centers in the frame of Cooperation Programmes promoted by the Italian Ministry of Foreign Affairs mainly in favour of the Less Developing Countries (LDC) of World Meteorological Organisation (WMO) Regional Association I (Africa). The Institute, as a branch of the WMO-Regional Meteorological Training Centre for Region VI (Europe), organizes also international training courses of high-level in Meteorology, Climatology and Remote Sensing applied to environment and agriculture fields. Moreover, considering the increasing evolution of the GIS functions for meteorological information users, IBIMET has promoted in 2005 the EU COST Action 719 Summer School on "GIS applications in meteorology and climatology''. The paper offers an overview of the main institute training programmes organised to share the results of research activities and operational projects, through the exploitation of innovative technologies and tools like GIS.
Federated data bases for the development of an operational monitoring and forecasting system of the ocean: the THREDDS Dataset Merger
Authors: Nativi S. , Manzella G. M. R. , Paolucci F. , Mazzetti P. , Pecci L. , Bigagli L. , Reseghetti F.
Published: April 2010

Abstract. During the last decade, operational monitoring and forecasting systems have been developed in all the European seas. The exchange of data and products and the development of services for a wide community of users pose some fundamental issues, whose solution has become a priority in integrated and GMES referring projects, such as the MERSEA European project. These projects aim to develop a European system for operational monitoring and forecasting on global and regional scales of ocean physics, bio-chemistry and ecosystems. GMES system and its operational projects need to federate resources and expertise coming from diverse organizations working on different Earth Sciences fields (e.g. satellite data processing, in situ observing systems, data management, ocean and ecosystem modeling, etc.). Therefore, it is required a Marine Information Management (MIM) system capable of facilitating the regular real-time exchange of high quality information, data and products. Moreover, MIM system must provide appropriate information for a wide range of external users both in real-time and delayed mode. In this paper an architecture based on the OPeNDAP/THREDDS technology is proposed as a solution for these operational systems. In this context, a catalog merging solution is introduced for the MIM system, which results in the design and development of the THREDDS Dataset Merger (TDM): a set of services meant to merge THREDDS Dataset Inventory Catalogs, so to achieve a unique catalog service for a whole database federation. TDM service merges distributed and autonomous THREDDS catalogs in order to work out a virtual merged catalog. The TDM service was extended in order to provide automatic catalogs synchronization. This service allows extending the pull-based TDM paradigm to support push-based applications. Some security issues are also considered.
Lively data: discover, browse and access ocean altimetry data on internet
Authors: Rosmorduc V. , Jolibois T. , Lauret O.
Published: April 2010

Abstract. The Products and Services (P&S) department in the Space Oceanography Division at CLS (Collecte, Localisation, Satellites) is in charge of distributing and promoting altimetry and operational oceanography data. The department is thus involved in the Aviso satellite altimetry project (the French service which distributes altimetry products since 1992), in the Mercator ocean operational forecasting system, and in the European Godae/Mersea ocean portal. Aiming to a standardisation and a common vision and management of all these ocean data, all these projects, led to the implementation of several Opendap/LAS Internet servers (Baudel et al., 2004). Some of the possibilities of the tools, as well as how-to information will be highlighted, as they are in the "Lively data'' section of Aviso website (see http://www.aviso.oceanobs.com/html/donnees/las/). Moreover, with a two-year experience we now have some feedback and analysis of how people – users, would-be users and students alike – are using this tool, some ideas for possible enhancements, etc.
Internet Data Distribution – extending real-time data sharing throughout the Americas
Authors: Yoksas T. , Gambi de Almeida W. , Garrana Coelho D. , Castro Leon V. , Spangler T.
Published: April 2010

Abstract. The Unidata Program Center (Unidata) of the University Corporation of Atmospheric Research (UCAR) is involved in three international collaborations whose goals are extension of real-time data delivery-to and sharing-of locally held datasets-by educational institutions throughout the Americas. These efforts are based on the use of Unidata's Internet Data Distribution (IDD) system which is built on top of its proven Local Data Manager Version 6 (LDM-6) technology. The Unidata IDD is an event-driven network of cooperating Unidata LDM servers that distributes discipline-neutral data products in near real-time over wide-area networks. The IDD, a collaboration of over 150 mostly North American institutions of higher education, has been the primary source of real-time atmospheric science data for the US university community for over a decade,. In addition to providing a highly reliable mechanism for delivering real-time data, the IDD allows users to easily share locally held datasets.
Modelling spring flood in the area of the Upper Volga basin
Authors: Helms M. , Evdakov O. , Ihringer J. , Nestmann F.
Published: April 2010

Abstract. Integrated river-basin management for the Volga river requires understanding and modelling of the flow process in its macro-scale tributary catchments. At the example of the Kostroma catchment (16 000 km2), a method combining existing hydrologic simulation tools was developed that allows operational modelling even when data are scarce. Emphasis was placed on simulation of three processes: snow cover development using a snow-compaction model, runoff generation using a conceptual approach with parameters for seasonal antecedent moisture conditions, and runoff concentration using a regionalised unit hydrograph approach. Based on this method, specific regional characteristics of the precipitation-runoff process were identified, in particular a distinct threshold behaviour of runoff generation in catchments with clay-rich soils. With a plausible overall parameterisation of involved tools, spring flood events could successfully be simulated. Present paper mainly focuses on the simulation of a 16-year sample of snowmelt events in a meso-scale catchment. An example of regionalised simulation in the scope of the modelling system "Flussgebietsmodell" shows the capabilities of developed method for application in macro-scale tributary catchments of the Upper Volga basin.
Investigation of parameter uncertainty and identifiability of the hydrological model WaSiM-ETH
Authors: Wriedt G. , Rode M.
Published: April 2010

Abstract. The identification of optimum model parameters may be influenced by temporal or event-specific changes of optimum parameter ranges and the length and information content of calibration data. These effects were studied for the hydrological model WaSiM-ETH in a 170 km2 catchment. Based on a Monte-Carlo simulation including seven model parameters, we investigated temporal and state dependent changes of parameter identifiability using the DYNIA algorithm. The effect of data length was studied using a modified DYNIA approach based on a growing window algorithm. The DYNIA analysis revealed temporal changes of identifiability for the snow melt runoff parameter cmelt, which is only identifiable during winter runoff, and for the drainage density parameter drd. The drd parameter was closely related to observed discharge (or catchment moisture), when re-ordering the time series by discharge. Such dependencies probably result from processes not included in model equations. The growing window analysis shows that more than one year of data did not result in improved identification of model parameters cmelt and drd. Using the re-ordered data series, good identifiability of cmelt was bound to high discharges, while identifiability of drd changed with the addition of further values in descending or ascending order. The methodology revealed structural problems with regard to the parameter drd, which are not yet completely understood and require further investigation.
Analysis of runoff for the Baltic basin with an integrated Atmospheric-Ocean-Hydrology Model
Authors: Richter K.-G. , Ebel M.
Published: April 2010

Abstract. A fully integrated Atmospheric-Ocean-Hydrology Model (BALTIMOS = Baltic Integrated Model System) has been developed using existing model components. Experiment and model design has been adapted to the Baltic basin with a catchment area of approximately 1 750 000 km2. A comprehensive model validation has been completed using large meteorological and hydrological measurement database. Comparing the calculated runoff from the integrated and non-integrated model system with measurements for three different representative subbasins and the entire Baltic basin, the effect of the integrated model is described. The results display a good agreement between measured and calculated runoff. The effect of the integrated model is rather negligible looking at computed mean values: There is no significant difference between mean monthly runoff of the integrated and non-integrated model during the year with the exception of spring. There is a delay of one month with regard to peak runoff for the non-integrated model in spring caused by different interactive processes during the melting period.
Characterization of a thermodenuder-particle beam mass spectrometer system for the study of organic aerosol volatility and composition
Authors: Faulhaber A. E. , Thomas B. M. , Jimenez J. L. , Jayne J. T. , Worsnop D. R. , Ziemann P. J.
Published: April 2010

Abstract. This paper describes the development and evaluation of a method for measuring the vapor pressure distribution and volatility-dependent mass spectrum of organic aerosol particles using a thermodenuder-particle beam mass spectrometer. The method is well suited for use with the widely used Aerodyne Aerosol Mass Spectrometer (AMS) and other quantitative aerosol mass spectrometers. The data that can be obtained are valuable for modeling organic gas-particle partitioning and for gaining improved composition information from aerosol mass spectra. The method is based on an empirically determined relationship between the thermodenuder temperature at which 50% of the organic aerosol mass evaporates (T50) and the organic component vapor pressure at 25°C (P25). This approach avoids the need for complex modeling of aerosol evaporation, which normally requires detailed information on aerosol composition and physical properties. T50 was measured for a variety of monodisperse, single-component organic aerosols with known P25 values and the results used to create a logP25 vs. T50 calibration curve. Experiments and simulations were used to estimate the uncertainties in P25 introduced by variations in particle size and mass concentration as well as mixing with other components. A vapor pressure distribution and volatility-dependent mass spectrum were then measured for laboratory-generated secondary organic aerosol particles. Vaporization profiles from this method can easily be converted to a volatility basis set representation, which shows the distribution of mass vs. saturation concentration and the gas-particle partitioning of aerosol material. The experiments and simulations indicate that this method can be used to estimate organic aerosol component vapor pressures to within approximately an order of magnitude and that useful mass-spectral separation based on volatility can be achieved.