Science.gov

Sample records for aasta jaanuaritormiga gudrun

  1. Sting jets in severe northern European wind storms: a case study of Windstorm Gudrun

    NASA Astrophysics Data System (ADS)

    Baker, Laura; Gray, Suzanne; Clark, Peter

    2010-05-01

    Extratropical cyclones often produce strong surface winds, mostly associated with low-level jets along the warm and cold fronts. Some severe extratropical cyclones have been found to produce an additional area of localised strong, and potentially very damaging, surface winds during a certain part of their development. These strong winds are associated with air that originates within the cloud head, exiting at the tip of the cloud head and descending rapidly from there to the surface. This rapidly descending air associated with the strong surface winds is known as a sting jet. The aim of this project is to determine the mechanisms that lead to sting jets and develop diagnostics for predicting their formation and development. In previous work mesoscale slantwise circulations have been found in the cloud heads of sting jet storms; these have been speculated to be due to the release of conditional symmetric instability (CSI). Here we present an analysis of the windstorm known as "Gudrun", which passed over the UK and northern Europe in January 2005. A sting jet has been identified in this case, and the relationship between this sting jet feature and the release of CSI has been examined using two diagnostics for CSI: SCAPE (slantwise convective available potential energy) and a diagnostic based on moist potential vorticity (MPV). SCAPE exists near the tip of the cloud head and decreases during the time leading up to and during the sting jet's descent, indicating that CSI is being released during this time. This is further supported by a corresponding decrease in the MPV-based CSI diagnostic during the same period.

  2. Community occupancy before-after-control-impact (CO-BACI) analysis of Hurricane Gudrun on Swedish forest birds.

    PubMed

    Russell, James C; Stjernman, Martin; Lindström, Åke; Smith, Henrik G

    2015-04-01

    Resilience of ecological communities to perturbation is important in the face of increased global change from anthropogenic stressors. Monitoring is required to detect the impact of, and recovery from, perturbations, and before-after-control-impact (BACI) analysis provides a powerful framework in this regard. However, species in a community are not observed with perfect detection, and occupancy analysis is required to correct for imperfect detectability of species. We present a Bayesian community occupancy before-after-control-impact (CO-BACI) framework to monitor ecological community response to perturbation when constituent species are imperfectly detected. We test the power of the model to detect changes in community composition following an acute perturbation with simulation. We then apply the model to a study of the impact of a large hurricane on the forest bird community of Sweden, using data from the national bird survey scheme. Although simulation shows the model can detect changes in community occupancy following an acute perturbation, application to a Swedish forest bird community following a major hurricane detected no change in community occupancy despite widespread forest loss. Birds with landscape occupancy less than 50% required correcting for detectability. We conclude that CO-BACI analysis is a useful tool that can incorporate rare species in analyses and detect occupancy changes in ecological communities following perturbation, but, because it does not include abundance, some impacts may be overlooked. PMID:26214914

  3. Collaborative Life History: Different Experiences of Spending Time in an Institution in Iceland

    ERIC Educational Resources Information Center

    Hreinsdottir, Eyglo Ebba; Stefansdottir, Gourun

    2010-01-01

    This article was first written as a presentation to the International Seminar held at the Open University in July 2008. It is based on cooperation between two women, Eyglo Ebba Hreinsdottir and Gudrun Stefansdottir, one who lived at an institution and another who worked there. Ebba moved to an institution in 1969 when she was 19 years old. Gudrun…

  4. Preliminary tests for Salix sp. tolerance to heavy metals (Cd, Ni, Pb)

    NASA Astrophysics Data System (ADS)

    Corneanu, Mihaela; Hernea, Cornelia; Butnariu, Monica; Corneanu, Gabriel; Sărac, Ioan; Hollerbach, Wilhelm; Neţoiu, Constantin; Petcov, Andreea Adriana

    2014-05-01

    The species of Salix genus constitute potential sources of germplasm in the prevention of the environment degradation, and offer remedy for about two third from the all degradation types. The majority of the willow species, present a good adaptation to hypoxic conditions, feature which suggest that they manifest a preference for mineral nutrition in comparison with organic one. Thus, many of willow species can be developed on soils with a big amount of minerals and/or radionuclides, being both phytoremediatory species, as well as pioneer ones, contributing to the restoration of soil. Thus, the willow species, posses the capacity for development in degraded areas, natural or anthropic, as swamps, abandoning crops areas, sandy dune, riparian sandy areas, gravels, a.o. In this paper are present some laboratory comparative tests of heavy metals tolerance on four Salix sp. genotypes: clone 202 (Salix alba), hybrid 892 (Salix alba), Inger (Salix viminalis) and Gudrun (Salix viminalis). The genotypes of Salix alba are native from Romania, produced in the Forest Research and Management Institute Bucharest, while the genotypes of Salix viminalis are native from Sweden, but the plant material was produced under license in Romania by REBINA Agrar SRL. As plant material were used one-year-old cuttings (5-10 cm long), with 2-6 buds each. Per genotype, per heavy metal and each of three concentration five replication were used. There were ten experimental variants for each genotype: three concentrations for each of the heavy metals; concentrations selected, in the accordance SR ISO 11269-2/March 1999 and Control (tap water). The cuttings were maintained in metalic solutions for 15 days. In the days 7th and 15th, were performed biometrical observations on: the roots number and length, the shoots number and length, the leaves number/shoot, viability of the shoots. At the end of the experiment the content in heavy metals was determined in roots and shoots (by atomic absorption

  5. Storm Effects on Net Ecosystem Productivity in Boreal Forests

    NASA Astrophysics Data System (ADS)

    Vestin, Patrik; Grelle, Achim; Lagergren, Fredrik; Hellström, Margareta; Langvall, Ola; Lindroth, Anders

    2010-05-01

    Regional carbon budgets are to some extent determined by disturbance in ecosystems. Disturbance is believed to be partly responsible for the large inter-annual variability of the terrestrial carbon balance. When neglecting anthropogenic disturbance, forest fires have been considered the most important kind of disturbance. However, also insect outbreaks and wind-throw may be major factors in regional carbon budgets. The effects of wind-throw on CO2 fluxes in boreal forests are not well known due to lack of data. Principally, the reduced carbon sequestration capacity, increased substrate availability and severe soil perturbation following wind-throw are expected to result in increased CO2 fluxes from the forest to the atmosphere. In January 2005, the storm Gudrun hit Sweden, which resulted in approx. 66 × 106m3storm-felled stem wood distributed over an area of approx. 272 000 ha. Eddy covariance flux measurements started at storm-felled areas in Asa and Toftaholm in central Sweden during summer 2005. Data from the first months suggests increased CO2 fluxes by a factor of 2.5-10, as compared to normal silviculture (clear-cutting). An important question is how long such enhanced CO2 fluxes persist. The BIOME-BGC model will be calibrated against measured CO2 fluxes from both sites for 2005 through 2009. Modeled data will be used to fill gaps in the data sets and annual carbon balances will be calculated. Data from Asa and Toftaholm will be presented at the conference.

  6. BOOK REVIEW: Astronomie von Olbers bis Schwarzschild. Nationale Entwicklungen und internationale Beziehungen im 19. Jahrhundert (Acta Historica Astronomiae Vol. 16)

    NASA Astrophysics Data System (ADS)

    Sterken, C.; Dick, W. R.; Hamel, J.

    2002-12-01

    astronomers in his days, when his working place at Altona still belonged to the kingdom of Denmark. This paper is followed by a second one by the same author and deals with the correspondence of H. C. Schumacher and H C. Oersted (1777-1851) and shows how intense and diverse their cooperation was. In a subsequent paper, Wolfgang Kokott describes the role of the Astronomisches Jahrbuch (published from 1776 by the Royal Academy of Sciences at Berlin), a ranking international publication, with Bode's modest Berlin Observatory serving as a clearinghouse of information originating from virtually all European countries. "Karl Schwarzschild and the professionalisation of Astrophysics" is the title of Theodor Schmidt-Kaler's contribution and presents Schwarzschild's contributions to professionalization of astronomy: establishment of course lectures and a permanent astrophysical laboratory, a tight connection between teaching and research, stimulations and suggestions for astronomy at high school and for the formation of high school teachers, international organisation, and the planning of a southern observatory. Peter Habison describes the contribution of Leo de Ball (1853-1916, Director of the Kuffner Observatory in Vienna) to international astronomy. Internationalization in astronomy is also discussed in a following paper by Gudrun Wolfschmidt on the establishment of the Vereinigte Astronomische Gesellschaft, the international Astronomische Gesellschaft in 1863 and finally the International Astronomical Union in 1919. In the second but last paper of the book, Hilmar Duerbeck describes the history of the Chilean National Observatory, beginning with its origins out of Gilliss' US Naval Expedition to the Southern Hemisphere in 1849, over its directors Moesta, Vergara, Obrecht and Ristenpart, to the middle of the 20th century. The paper also includes the astronomical development at the Universidad Catolica and various international expeditions, which aimed at the observations of solar

  7. Gratkorn - A new late Middle Miocene vertebrate fauna from Styria (Late Sarmatian, Austria)

    NASA Astrophysics Data System (ADS)

    Gross, M.; Böhme, M.; Prieto, J.

    2009-04-01

    still under investigation. We are especially grateful to Gudrun Daxner-Höck, Ur

  8. Mechanical Properties of Gels; Stress from Confined Fluids

    SciTech Connect

    George W. Scherer

    2009-12-01

    Garofalini (Rutgers), who has developed the best simulations of water ever reported by use of molecular dynamics. Simulated heating of water in small pores provided quantitative agreement with experiments, and showed that the origin of the high expansion is the altered structure of water in the first two molecular layers adjacent to the pore wall. The final focus of the project was to understand the damage done by crystals growing in small pores. For example, the primary cause of damage to ancient monuments in the Mediterranean Basin is growth of salt crystals in the pores of the stone. Salt may enter stone as a result of capillary rise of groundwater, by leaching of mortar joints, deposition of marine spray, or reactions with atmospheric pollutants (such as oxides of nitrogen or sulfur). As the water evaporates, the salt solution becomes supersaturated and crystals precipitate. Stress results, because the salt usually repels the minerals in the pore walls. Our goal was to identify the factors contributing to the repulsion, so that we could develop a chemical treatment to reduce the repulsion and hence the stress. (We have recently demonstrated an effective treatment as part of a separately funded study.) In collaboration with Prof. Garofalini, molecular dynamics simulations have been done that correctly reproduce the structure of water around dissolved ions of sodium and chloride. We simulated the interaction between crystals of sodium chloride and quartz, and found that this particular system exhibits attractive forces, in agreement with experiment. The origin of the attraction is the orientation of dipolar water molecules near the surfaces of the crystals. Similar calculations now must be done in systems, such as potassium chloride and quartz, where the interaction is repulsive. This grant supported the education of two doctoral students, Hang-Shing Ma (Ph.D., 2002) and Melanie Webb (Ph.D. expected 2010), three post-doctoral researchers, Joachim Gross, Gudrun Reichenauer

  9. Gratkorn - A new late Middle Miocene vertebrate fauna from Styria (Late Sarmatian, Austria)

    NASA Astrophysics Data System (ADS)

    Gross, M.; Böhme, M.; Prieto, J.

    2009-04-01

    still under investigation. We are especially grateful to Gudrun Daxner-Höck, Ursula Göhlich (both Natural History Museum Vienna) and Getrud Rössner (University of Munich) for their comments to the rodents, ruminants, proboscidians and bird remains. References Böhme, M., Ilg, A., Winklhofer, M. 2008. Late Miocene "washhouse" climate in Europe.- Earth and Planetary Science Letters, 275: 393-401. Gross, M., 2008. A limnic ostracod fauna from the surroundings of the Central Paratethys (Late Middle Miocene/Early Late Miocene; Styrian Basin; Austria).- Palaeogeography, Palaeoclimatology, Palaeoecology, 264/3-4: 263-276. Harzhauser, M., Gross, M. & Binder, H., 2008. Biostratigraphy of Middle Miocene (Sarmatian) wetland systems in an Eastern Alpine intramontane basin (Gratkorn Basin, Austria): the terrestrial gastropod approach.- Geologica Carpathica, 59/1: 45-58.

  10. Obituary: Jörn Rossa (1969-2009)

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri

    2009-12-01

    Jörn Rossa (often spelled Joern Rossa) passed away on September 19, 2009 at the young age of 40 in Mainz, Germany from a virulent fast-acting blood cancer. He was born in that same city on March 17, 1969 to Alfred and Gudrun Rossa, who survive their only child. Joern had a deep, lifelong love of astronomy, as evidenced by the handwritten letters he wrote in his youth to prominent astronomers and astronauts for their perspectives, signatures and reprints, the popular astronomy magazines which he collected for decades, the decision to abandon a career as a locomotive driver and relearn the math and physics required to pursue his passion, the many papers he published himself, and the numerous space shuttle launches he made a point to personally attend at Kennedy Space Center. Since High School, Joern carried out observations using his own telescope, traveled with friends to remote locations to practice "serious" astrophotography, and lectured at a local amateur club. After attaining his undergraduate degree at the University of Heidelberg (Germany) in 1996, Joern continued his education at the Ruhr-University Bochum in Germany, where he worked under the guidance of Ralf-Juergen Dettmar. He received his Ph.D. degree in 2001 with a thesis focusing on extraplanar diffuse ionized gas and dust in the halos of edge-on spiral galaxies. He performed the largest-to-this-day ground-based H-alpha survey of a large number of galaxies, quantified their extraplanar ISM, and correlated its properties with the starburst activity in the galaxy disk. After his graduation, Joern stayed in Bochum for another year as a Postdoctoral Associate. During this time he expanded his interests in the same general subject area through the use of X-ray (XMM, Chandra) and radio observations. His interest in the ISM of nearby galaxies continued through his subsequent postdoctoral career. He analyzed high-spatial resolution Hubble Space Telescope (HST) WFPC2 H-alpha data of the edge-on non

  11. Obituary: Jörn Rossa (1969-2009)

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri

    2009-12-01

    Jörn Rossa (often spelled Joern Rossa) passed away on September 19, 2009 at the young age of 40 in Mainz, Germany from a virulent fast-acting blood cancer. He was born in that same city on March 17, 1969 to Alfred and Gudrun Rossa, who survive their only child. Joern had a deep, lifelong love of astronomy, as evidenced by the handwritten letters he wrote in his youth to prominent astronomers and astronauts for their perspectives, signatures and reprints, the popular astronomy magazines which he collected for decades, the decision to abandon a career as a locomotive driver and relearn the math and physics required to pursue his passion, the many papers he published himself, and the numerous space shuttle launches he made a point to personally attend at Kennedy Space Center. Since High School, Joern carried out observations using his own telescope, traveled with friends to remote locations to practice "serious" astrophotography, and lectured at a local amateur club. After attaining his undergraduate degree at the University of Heidelberg (Germany) in 1996, Joern continued his education at the Ruhr-University Bochum in Germany, where he worked under the guidance of Ralf-Juergen Dettmar. He received his Ph.D. degree in 2001 with a thesis focusing on extraplanar diffuse ionized gas and dust in the halos of edge-on spiral galaxies. He performed the largest-to-this-day ground-based H-alpha survey of a large number of galaxies, quantified their extraplanar ISM, and correlated its properties with the starburst activity in the galaxy disk. After his graduation, Joern stayed in Bochum for another year as a Postdoctoral Associate. During this time he expanded his interests in the same general subject area through the use of X-ray (XMM, Chandra) and radio observations. His interest in the ISM of nearby galaxies continued through his subsequent postdoctoral career. He analyzed high-spatial resolution Hubble Space Telescope (HST) WFPC2 H-alpha data of the edge-on non