7,973 research outputs found

    Operational tsunami modelling with TsunAWI – recent developments and applications

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    In this article, the tsunami model TsunAWI (Alfred Wegener Institute) and its application for hindcasts, inundation studies, and the operation of the tsunami scenario repository for the Indonesian tsunami early warning system are presented. TsunAWI was developed in the framework of the German-Indonesian Tsunami Early Warning System (GITEWS) and simulates all stages of a tsunami from the origin and the propagation in the ocean to the arrival at the coast and the inundation on land. It solves the non-linear shallow water equations on an unstructured finite element grid that allows to change the resolution seamlessly between a coarse grid in the deep ocean and a fine representation of coastal structures. During the GITEWS project and the following maintenance phase, TsunAWI and a framework of pre- and postprocessing routines was developed step by step to provide fast computation of enhanced model physics and to deliver high quality results

    The artificial method of the ozone layer restoration

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    The problem of the ozone holes became known for mankind at the 80-th years last century. Ozone loss was first detected in the stratosphere over Antarctica. In 1985, Vienna Conception related to the ozone layer protection was proclaimed. In 1987, one hundred and forty nine nations signed the Montreal Protocol. But these actions didn’t solve the problem. The ozone holes exist and increase. The biggest ozone hole over Antarctica reached 24 million square kilometers in 2005. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/797

    Current status of TsunAWI contributions to the Indonesia Tsunami Early Warning System (InaTEWS) with a comparison of warning products from near-realtime easyWave and precomputed TsunAWI simulations

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    Abstract: The Indonesia Tsunami Early Warning System delivers simulated tsunami forecasts in two different ways: either matching scenario(s) from a pre-computed database or running on-the-fly tsunami simulation. Recently, the database has been extended considerably taking into account additional source regions not covered in earlier stages of the system. In this contribution, we present the current status of the data base coverage as well as a study investigating the warning products obtained by the two modeling approaches. The pre-computed tsunami scenarios are based on the finite element model TsunAWI that employs a triangular mesh with resolution ranging from 20km in deep ocean to 300m in coastal areas and to as much as 50m in some highly resolved areas. TsunAWI solves the nonlinear shallow water equations and contains a wetting-drying inundation scheme. The on-the-fly propagation model easyWave solves the linear shallow water equations on a regular finite-difference grid with a resolution of about 1 km and utilizes several simple options to estimate coastal impact. This model is used for forecasting after a tsunami has been generated in an area not covered by the database or after a moment tensor solution shows an earthquake focal mechanism not present in the database. Since warning products like estimated wave height (EWH) and estimated time of arrival (ETA) along the coast are based on modeling results, it is crucial to compare the resulting forecasted warning levels obtained by the two approaches. Resolutions and numerical settings of both models are quite different, therefore variations in the resulting outputs are to be expected; nevertheless, the extent of differences in warning levels should not be too large for identical sources. In the present study, we systematically investigate differences in resulting warning products along InaTEWS forecast points facing the Sunda arc.  Whereas the finite-element mesh of TsunAWI covers the coast up to a terrain height of 50m and warning products have been pre-calculated directly in the forecast points, easyWave offers several options for their approximation including projections from offshore grid points or vertical wall. Differences and potential reasons for variations of warning products like the role of bathymetry resolution as well as the general approach for the assessment of EWH and ETA for different modeling frameworks are discussed

    On the remote sensing of oceanic and atmospheric convection in the Greenland Sea by synthetic aperture radar

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    In this paper we discuss characteristic properties of radar signatures of oceanic and atmospheric convection features in the Greenland Sea. If the water surface is clean (no surface films or ice coverage), oceanic and atmospheric features can become visible in radar images via a modulation of the surface roughness, and their radar signatures can be very similar. For an unambiguous interpretation and for the retrieval of quantitative information on current and wind variations from radar imagery with such signatures, theoretical models of current and wind phenomena and their radar imaging mechanisms must be utilized. We demonstrate this approach with the analysis of some synthetic aperture radar (SAR) images acquired by the satellites ERS-2 and RADARSAT-1. In once case, an ERS-2 SAR image an a RADARSAT-1 ScanSAR image exhibit pronounced cell-like signatures with length scales on the order of 10-20 km and modulation depths of about 5-6 dB and 9-10 dB, respectively. Simulations with a numerical SAR imagaing model and various input current and wind fields reveal that the signatures in both images can be expained consistently by wind variations on the order of±2.5 ms, but not by surface current variations on realistic orders of magnitude. Accordingly, the observed features must be atmospheric convection cells. This is confirmed by visible typical cloud patterns in a NOAA AVHRR image of the test scenario. In another case, the presence of an oceanic convective chimney is obvious from in situ data, but no signatures of it are visible in an ERS-2 SAR image. We show by numerical simulations with an oceanic convection model and our SAR imaging model that this is consistent with theoretical predictions, since the current gradients associated with the observed chimney are not sufficiently strong to give rise to significant signatures in an ERS-2 SAR image under the given conditions. Further model results indicate that it should be generally difficult to observe oceanic convection features in the Greenland Sea with ERS-2 or RADARSAT-1 SAR, since their signatures resulting from pure wave-current interaction will be too weak to become visible in the noisy SAR images in most cases. This situation will improve with the availability of future high-resolution SARs such as RADARSAT-2 SAR in fine resolution mode (2004) and TerraSAR-X (2005) which will offer significantly reduced speckle noise fluctuations at comparable spatial resolutions and thus a much better visibility of small image variations on spatial scales on the order of a few hundred meters

    Modeling efforts for the Lena delta and Laptev Sea regions

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    The Lena River is one of the largest rivers in the Arctic and has the largest delta. Given the large territory of the Lena Delta, the direct measurements are by far insufficient, calling for a modeling approach. However, most of the models, which include the Laptev Sea shelf zone, do not resolve the Lena Delta and as a consequence lose information about Lena river stream changes using input data with insufficient quality. In the current work we present the hydrodynamics model for the Lena Delta region and full baroclinic model for the Laptev Sea shelf area. The available hydrological information in the Lena Delta was collected, analyzed and used for the model verification. The developed hydrodynamics model provides the first necessary step for the further modeling efforts in the area. It also gives an input for the larger scale models resolving hydrodynamics of more than twenty main Lena River freshwater channels with switched-on wetting/drying option. Additionally the Lena Plume dynamics in the Lena Delta region of the Laptev Sea are explored by us in simulations performed with the FVCOM (Finite Volume Coastal Ocean Model). The impact of winds and tides on the Lena plume propagation is analysed based on simulations for the summer season of 2008 and also on idealized experiments. For that period, the simulated distributions of temperature and salinity agree well with the observations, including the thick-ness and border position of the buoyant plume. The model simulates the most energetic semi-diurnal and diurnal tidal constituents. The amplitudes and phases of the tidal components at the open boundary were derived from AOTIM5 and TPXO7.1 with corrections. These corrections noticeably improve the agreement of the modelled tidal maps with available tide gauge data

    Physician Screening for Intimate Partner Violence in Vermont

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    Introduction: The term intimate partner violence (or IPV) refers to a threat of abuse or actual psychological, physical, and/or sexual abuse perpetrated by a former or current intimate partner. IPV is an important public health issue that crosses socioeconomic lines. Approximately 4.8 million women experience physical or sexual assault perpetrated by their intimate partner each year in the US. There are no reliable statistics for how many women suffer psychological abuse, but the numbers are likely much higher. Physical, psychological, or sexual injuries can have wide ranging effects, including increased mortality. Although it has been firmly established that the prevalence of IPV is high, physician involvement in screening and diagnosing IPV has historically been very low. Previous studies have addressed IPV screening in other parts of the country. In one study, less than 15% of female patients reported being asked by a health professional about IPV, even though studies have shown that the majority of female patients would reveal their abuse if asked. Also, most physicians screened for IPV when the patient presented with physical trauma, but few screened all patients regularly. The more aware physicians were about IPV, the more likely they were to screen in all clinical settings. While both men and women are victims of IPV, and IPV can have a large effect on the children of the abused, only the screening and treatment of women was explored here. The purpose of this study was to examine the state of IPV screening in Vermont. The objectives were as follows: - ?Estimate the IPV screening, intervention, and policy practices of Vermont physicians ?- Examine the role of physicians in screening and intervention ?- Explore physicians’ knowledge of IPV resourceshttps://scholarworks.uvm.edu/comphp_gallery/1042/thumbnail.jp

    FESOM_coastal

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    There is a growing need in the high quality estimations of long-term dynamics and circulation features in the coastal areas to answer major present and future societal, ecosystem and other questions, because of changing climate. On long time scales, the coastal dynamics change not only because of variable forcing, but also due to exchanges with the evolving global ocean. Over recent years, considerable efforts have been invested into developing regional models and applying them to the coastal areas. These models are used by different institutions to study currents, sediment transport and ecosystem dynamics. They are well-established tools equipped with necessary parameterizations and modules that may be required in shelf or coastal modeling. However, they are regional models with open boundaries. When it comes to applying them to study long-term trends and variability in the regional sea, they have to be coupled to a large-scale modeling system. However, numerical algorithms used by global models can be insufficient to simulate coastal dynamics. There are issues related to vertical advection and mixing, stability in case of very thin sigma layers, absence of wetting/drying option etc. One more point is the choice of time step in case of highly varying resolution. Coastal refinement can be added to the global models, but at the same time they will lose efficiency. Unstructured-mesh coastal models are too dissipative and expensive to simulate global circulation at present. A way out of this situation is coupling global and coastal models (one or two ways nesting). To reach this goal we present a coastal branch of the global model FESOM (Danilov et al. 2004, Wang et al. 2014). FESOM is a well-established large-scale ocean circulation model which is tested in numerous applications and participates in ocean model intercomparison project (see CORE-II virtual special issue of Ocean Modelling). It is the first model worldwide which provides multi-resolution functionality to large-scale ocean modeling, allowing one to bridge the gap between the scales and has the finite volume version at the current stage. FESOM_coastal treats the input/output characteristics in the same manner and share partly physical core with the global solution. It supports full coastal functionality, has cell-vortex finite volume discretization and works on any configurations of triangular, quadrangular or hybrid meshes
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