Numerical weather prediction relevant to the monsoon problem

In this short paper we have identified some of the modelling groups that have the capability of simulating or carrying out short range numerical weather prediction over the monsoon belt. We have next outlined some of the important and desirable ingredients for a multilevel primitive equation model over the tropics, with most of the emphasis on the present version of Florida State University's Tropical Prediction Model. Finally, we present briefly some important results based on the present version of our prediction models that relate to the NWP efforts over the monsoon belt. Here we have identified the importance of mountains, convection, the radiative heating balance of the earth's surface, and the planetary boundary layer over the Arabian Sea.     

A new concept and a preliminary design for a high resolution (HR) and very‐high resolution (VHR) spectrograph for the LBT

A way to fully exploit the large collecting area of modern 8–10m class telescopes is high resolution spectroscopy. Many astrophysical problems from planetary science to cosmology benefit from spectroscopic observations at the highest resolution currently achievable and would benefit from even higher resolutions. Indeed in the era of 8–10m class telescopes no longer the telescope collecting area but the size of the beam – which is related to the maximum size in which reflection gratings are manufactured – is what mainly limits the resolution. A resolution‐slit product R_φ ≃ 40,000 is the maximum currently provided by a beam of 20 cm illuminating the largest grating mosaics. We present a conceptual design for a spectrograph with R_φ ≃ 80,000, i.e. twice as large as that of existing instruments. Examples of the possible exploitation of such a high R_φ value, including spectropolarimetry and very high resolution (R ∼ 300,000), are discussed in detail. The new concept is illustrated through the specific case of a high resolution spectropolarimeter for the Large Binocular Telescope.     

r.massmov: an open-source landslide model for dynamic early warning systems

This paper illustrates the main characteristics of the newly developed landslide model r.massmov, which is based on the shallow water equations, and is capable of simulating the landslide propagation over complex topographies. The model is the result of the reimplementation of the MassMov2D into the free and open-source GRASS GIS with a series of enhancements aiming at allowing its possible integration into innovative early warning monitoring systems and specifically into Web processing services. These improvements, finalized at significantly reducing computational times, include the introduction of a new automatic stopping criterion, fluidization process algorithm, and the parallel computing. Moreover, the results of multi-spatial resolution analysis conducted on a real case study located in the southern Switzerland are presented. In particular, this analysis, composed by a sensitivity analysis and calibration process, allowed to evaluate the model capabilities in simulating the phenomenon at different input data resolution. The results illustrate that the introduced modifications lead to important reductions in the computational time (more than 90 % faster) and that, using the lower dataset resolution capable of guaranteeing reliable results, the model can be run in about 1 s instead of the 3.5 h required by previous model with not optimized dataset resolution. Aside, the results of the research are a series of new GRASS GIS modules for conducting sensitivity analysis and for calibration. The latter integrates the automated calibration program “UCODE” with any GRASS raster module. Finally, the research workflow presented in this paper illustrates a best practice in applying r.massmov in real case applications.     

A Crustal Model for the Eastern Alps Region and a New Moho Map in Southeastern Europe

In the last two decades, south-central Europe and the Eastern Alps have been widely explored by many seismic refraction experiments (e.g., CELEBRATION 2000, ALP 2002, SUDETES 2003). Although quite detailed images are available along linear profiles, a comprehensive, three-dimensional crustal model of the region is still missing. This limitation makes this region a weak spot in continental-wide comprehensive representations of crustal structure. To improve on this situation, we select and collect 37 published active-source seismic lines in this region. After geo-referencing each line, we sample them along vertical profiles—every 50?km or less along the line—and derive P-wave velocities in a stack of homogeneous layers (separated by discontinuities: depth of crystalline basement, top of lower crust, and Moho). We finally merge the information using geostatistical methods, and infer S-wave velocity and density using empirical scaling relations. We present here the resulting crustal model for a region encompassing the Eastern Alps, Dinarides, Pannonian basin, Western Carpathians and Bohemian Massif, covering the region within $45^{\circ}\text{--}51^{\circ}\hbox{N}$ and $11^{\circ} \text{--} 22^{\circ}\hbox{E}$ with a resolution of $0.2^{\circ} \times 0.2^{\circ}.$ We are also able to extend and update the map of Moho depth in a wider region within $35^{\circ}\text{--}51^{\circ}\hbox{N}$ and $12^{\circ}\text{--}45^{\circ}\hbox{E},$ gathering Moho values from the collected seismic lines, other published dataset and using the European plate reference EPcrust as a background. All the digitized profiles and the resulting model are available online.     

Damage identification of a 3D full scale steel–concrete composite structure with partial‐strength joints at different pseudo‐dynamic load levels

Partial‐strength composite steel–concrete moment‐resisting (MR) frame structures represent an open research field in seismic design from both a theoretical and an experimental standpoint. Among experimental techniques, vibration testing is a well‐known and powerful technique for damage detection, localization and quantification, where actual modal parameters of a structure at different states can be determined from test data by using system identification methods. However, the identification of semi‐rigid connections in framed structures is limited, and hence this paper focuses on a series of vibration experiments that were carried out on a realistic MR frame structure, following the application of pseudo‐dynamic and quasi‐static cyclic loadings at the European laboratory for structural assessment of the Joint Research Centre at Ispra, Italy, with the scope of understanding the structural behaviour and identifying changes in the dynamic response. From the forced vibration response, natural frequencies, damping ratios, modal displacements and rotations were extracted using the circle fitting technique. These modal parameters were used for local and global damage identification by updating a 3D finite element model of the intact structure. The identified results were then correlated with observations performed on the structure to understand further the underlying damage mechanisms. Finally, the latin hypercube sampling technique, a variant of the Monte Carlo method, was employed in order to study the sensitivity of the updated parameters of the 3D model to noise on the modal inputs. Copyright © 2009 John Wiley & Sons, Ltd.     

Use of ECMWF operational analyses for studies of the tropical cyclone environment

Summary This study examined ECMWF operational analyses of the outflow layer of two tropical cyclones (Allen, 1980; Elena, 1985) during their passage across the Atlantic and Caribbean. Wind fields and related derived quantities were compared to those from objective analyses of specialized data sets. Errors in center position and storm motion from the ECMWF analyses were also evaluated.Analyses of wind and angular momentum flux in 1985, subsequent to upgrading of the operational model, were superior to those from 1980. High-resolution, uninitialized analyses from 1985, however, provided no advantages over lower resolution, initialized analyses for the same time period. For all ECMWF analyses, azimuthally averaged (mean) tangential velocity, and thus mean vorticity, were well represented. Mean radial velocity and mean divergence were poorly represented. Problems with the latter arose primarily due to underestimation of outflow, especially in the 1980 analyses. Azimuthaleddy fluxes of angular momentum in the ECMWF analyses quantitatively differed from but qualitatively resembled, the control analyses.Vorticity maxima at 850 mb in the operational analyses most accurately defined the center position of the storms, with a mean error less than or equal to one grid point. In contrast, surface pressure minima failed to provide reliable estimates. Over open ocean and at early stages of storms, analysis quality was uneven, with occasional large position errors and widely varying locations of vorticity maxima in the vertical.Nevertheless, in regions surrounded by even a few rawinsondes, such as the Caribbean or Gulf of Mexico, ECMWF analyses contained sufficient information to allow individual case studies of the tropical cyclone environment. In the same regions, estimates of the eddy flux convergence of angular momentum were found to be accurate enough to aid in operational hurricane intensity prediction. Enhancements in resolution and model initialization at ECMWF since 1985 should further improve operational analyses of the tropical cyclone environment.With 11 Figures     

Towards an Automated Comparison of OpenStreetMap with Authoritative Road Datasets

OpenStreetMap (OSM) is an extraordinarily large and diverse spatial database of the world. Road networks are amongst the most frequently occurring spatial content within the OSM database. These road network representations are usable in many applications. However the quality of these representations can vary between locations. Comparing OSM road networks with authoritative road datasets for a given area or region is an important task in assessing OSM's fitness for use for applications like routing and navigation. Such comparisons can be technically challenging and no software implementation exists which facilitates them easily and automatically. In this article we develop and propose a flexible methodology for comparing the geometry of OSM road network data with other road datasets. Quantitative measures for the completeness and spatial accuracy of OSM are computed, including the compatibility of OSM road data with other map databases. Our methodology provides users with significant flexibility in how they can adjust the parameterization to suit their needs. This software implementation is exclusively built on open source software and a significant degree of automation is provided for these comparisons. This software can subsequently be extended and adapted for comparison between OSM and other external road datasets.     

Smart focal plane masks: rewritable photochromic films for astronomical multi‐object spectroscopy

Modern astronomical spectroscopy makes use of multi‐aperture slits placed in the focal plane of telescopes before light enters the spectrograph. Multiple object spectroscopy (MOS) allows several spectra to be obtained simultaneously with a multiplexing gain from the order of dozens of objects in 4m class telescopes to few hundreds in larger 8 m telescopes. Many of these devices make use of metal plates which are punched, milled or laser cut and can be used only for observation of a given astronomical target. A typical observing night requires from 4 to 20 MOS masks, which have to be prepared during an off‐line procedure, usually days before. Here we report an innovative technique to carry out multi object spectroscopy based on changes of properties of photochromic materials. Photochromic MOS masks consist of polymer thin films which can be made opaque or transparent in a restricted wavelength range using alternatively UV and visible light. Slit patterns can thus be easily written by means of a red diode laser on a UV preflashed plate. Writing time for a 10 × 10 arcmin plate is a few minutes and the whole procedure can be performed promptly after the acquisition of the field image and without mechanical debris as in milling or laser cutting. A computer controlled writing device suited for the AFOSC camera of the Asiago 1.8m telescope was built. The same focal plane mask can be UV erased and used more than 450 times. High contrasts have been reached by means of an appropriate passband filter in the light beam of the spectrograph. Our first successful observation run took place in January 2003. Spectra of selected stars in the crowded M67 cluster field and emission lines from the gaseous planetary nebula M97 were obtained. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Modeling of Landslide‐Generated Tsunamis with GRASS

The following research aims to enhance and spread the capacity of assessing risk due to landslide‐generated tsunamis by fostering the use of a GIS (Geographic Information System), and in this particular instance, an Open Source GIS (where “Open Source” can be loosely defined as freely available source code). For this purpose, we tested a procedure to be spatially implemented in the Open Source GRASS GIS through developing a module named r.impact.tsunami that simulates landslide‐generated tsunami. In this article we present its application in a case study performed on Como Lake (Lago di Como) in northern Italy. The review of the results identified sources of uncertainties while the model sensitivity outlined the influence of the parameters governing the model. Moreover, in order to verify the model validity, we implemented a new module (r.swe), that simulates the tsunami propagation and run‐up with the shallow water equations, and compared the results. Notwithstanding non‐negligible differences, the two models produced results of the same magnitude; this confirmed the validity of both models, although a rigorous validation of the models could not be performed due to the lack of observed data.