TY - JOUR A1 - Teriaca, Luca A1 - Andretta, Vincenzo A1 - Auchere, Frederic A1 - Brown, Charles M. A1 - Buchlin, Eric A1 - Cauzzi, Gianna A1 - Culhane, J. Len A1 - Curdt, Werner A1 - Davila, Joseph M. A1 - Del Zanna, Giulio A1 - Doschek, George A. A1 - Fineschi, Silvano A1 - Fludra, Andrzej A1 - Gallagher, Peter T. A1 - Green, Lucie A1 - Harra, Louise K. A1 - Imada, Shinsuke A1 - Innes, Davina A1 - Kliem, Bernhard A1 - Korendyke, Clarence A1 - Mariska, John T. A1 - Martinez-Pillet, Valentin A1 - Parenti, Susanna A1 - Patsourakos, Spiros A1 - Peter, Hardi A1 - Poletto, Luca A1 - Rutten, Robert J. A1 - Schuehle, Udo A1 - Siemer, Martin A1 - Shimizu, Toshifumi A1 - Socas-Navarro, Hector A1 - Solanki, Sami K. A1 - Spadaro, Daniele A1 - Trujillo-Bueno, Javier A1 - Tsuneta, Saku A1 - Dominguez, Santiago Vargas A1 - Vial, Jean-Claude A1 - Walsh, Robert A1 - Warren, Harry P. A1 - Wiegelmann, Thomas A1 - Winter, Berend A1 - Young, Peter T1 - LEMUR large european module for solar ultraviolet research JF - Experimental astronomy : an international journal on astronomical instrumentation and data analysis N2 - The solar outer atmosphere is an extremely dynamic environment characterized by the continuous interplay between the plasma and the magnetic field that generates and permeates it. Such interactions play a fundamental role in hugely diverse astrophysical systems, but occur at scales that cannot be studied outside the solar system. Understanding this complex system requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1'' and 0.3''), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 170 and 1270 . The LEMUR slit covers 280'' on the Sun with 0.14'' per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km s (-aEuro parts per thousand 1) or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission. KW - Sun: atmosphere KW - Space vehicles: instruments KW - Techniques: spectroscopy KW - ESA cosmic vision Y1 - 2012 U6 - https://doi.org/10.1007/s10686-011-9274-x SN - 0922-6435 VL - 34 IS - 2 SP - 273 EP - 309 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Warren, Ben H. A1 - Simberloff, Daniel A1 - Ricklefs, Robert E. A1 - Aguilee, Robin A1 - Condamine, Fabien L. A1 - Gravel, Dominique A1 - Morlon, Helene A1 - Mouquet, Nicolas A1 - Rosindell, James A1 - Casquet, Juliane A1 - Conti, Elena A1 - Cornuault, Josselin A1 - Maria Fernandez-Palacios, Jose A1 - Hengl, Tomislav A1 - Norder, Sietze J. A1 - Rijsdijk, Kenneth F. A1 - Sanmartin, Isabel A1 - Strasberg, Dominique A1 - Triantis, Kostas A. A1 - Valente, Luis M. A1 - Whittaker, Robert J. A1 - Gillespie, Rosemary G. A1 - Emerson, Brent C. A1 - Thebaud, Christophe T1 - Islands as model systems in ecology and evolution: prospects fifty years after MacArthur-Wilson JF - Ecology letters N2 - The study of islands as model systems has played an important role in the development of evolutionary and ecological theory. The 50th anniversary of MacArthur and Wilson's (December 1963) article, An equilibrium theory of insular zoogeography', was a recent milestone for this theme. Since 1963, island systems have provided new insights into the formation of ecological communities. Here, building on such developments, we highlight prospects for research on islands to improve our understanding of the ecology and evolution of communities in general. Throughout, we emphasise how attributes of islands combine to provide unusual research opportunities, the implications of which stretch far beyond islands. Molecular tools and increasing data acquisition now permit re-assessment of some fundamental issues that interested MacArthur and Wilson. These include the formation of ecological networks, species abundance distributions, and the contribution of evolution to community assembly. We also extend our prospects to other fields of ecology and evolution - understanding ecosystem functioning, speciation and diversification - frequently employing assets of oceanic islands in inferring the geographic area within which evolution has occurred, and potential barriers to gene flow. Although island-based theory is continually being enriched, incorporating non-equilibrium dynamics is identified as a major challenge for the future. KW - Community assembly KW - diversification KW - ecosystem functioning KW - genomics KW - island biogeography KW - islands as model systems KW - speciation Y1 - 2015 U6 - https://doi.org/10.1111/ele.12398 SN - 1461-023X SN - 1461-0248 VL - 18 IS - 2 SP - 200 EP - 217 PB - Wiley-Blackwell CY - Hoboken ER - TY - GEN A1 - Crisologo, Irene A1 - Warren, Robert A. A1 - Mühlbauer, Kai A1 - Heistermann, Maik T1 - Enhancing the consistency of spaceborne and ground-based radar comparisons by using beam blockage fraction as a quality filter T2 - Atmospheric Measurement Techniques N2 - We explore the potential of spaceborne radar (SR) observations from the Ku-band precipitation radars onboard the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) satellites as a reference to quantify the ground radar (GR) reflectivity bias. To this end, the 3-D volume-matching algorithm proposed by Schwaller and Morris (2011) is implemented and applied to 5 years (2012–2016) of observations. We further extend the procedure by a framework to take into account the data quality of each ground radar bin. Through these methods, we are able to assign a quality index to each matching SR–GR volume, and thus compute the GR calibration bias as a quality-weighted average of reflectivity differences in any sample of matching GR–SR volumes. We exemplify the idea of quality-weighted averaging by using the beam blockage fraction as the basis of a quality index. As a result, we can increase the consistency of SR and GR observations, and thus the precision of calibration bias estimates. The remaining scatter between GR and SR reflectivity as well as the variability of bias estimates between overpass events indicate, however, that other error sources are not yet fully addressed. Still, our study provides a framework to introduce any other quality variables that are considered relevant in a specific context. The code that implements our analysis is based on the wradlib open-source software library, and is, together with the data, publicly available to monitor radar calibration or to scrutinize long series of archived radar data back to December 1997, when TRMM became operational. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 474 Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-418198 ER - TY - JOUR A1 - Crisologo, Irene A1 - Warren, Robert A. A1 - Mühlbauer, Kai A1 - Heistermann, Maik T1 - Enhancing the consistency of spaceborne and ground-based radar comparisons by using beam blockage fraction as a quality filter JF - Atmospheric Measurement Techniques N2 - We explore the potential of spaceborne radar (SR) observations from the Ku-band precipitation radars onboard the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) satellites as a reference to quantify the ground radar (GR) reflectivity bias. To this end, the 3-D volume-matching algorithm proposed by Schwaller and Morris (2011) is implemented and applied to 5 years (2012–2016) of observations. We further extend the procedure by a framework to take into account the data quality of each ground radar bin. Through these methods, we are able to assign a quality index to each matching SR–GR volume, and thus compute the GR calibration bias as a quality-weighted average of reflectivity differences in any sample of matching GR–SR volumes. We exemplify the idea of quality-weighted averaging by using the beam blockage fraction as the basis of a quality index. As a result, we can increase the consistency of SR and GR observations, and thus the precision of calibration bias estimates. The remaining scatter between GR and SR reflectivity as well as the variability of bias estimates between overpass events indicate, however, that other error sources are not yet fully addressed. Still, our study provides a framework to introduce any other quality variables that are considered relevant in a specific context. The code that implements our analysis is based on the wradlib open-source software library, and is, together with the data, publicly available to monitor radar calibration or to scrutinize long series of archived radar data back to December 1997, when TRMM became operational. Y1 - 2018 U6 - https://doi.org/10.5194/amt-2018-101 SN - 1867-1381 SN - 1867-8548 VL - 11 IS - 9 SP - 5223 EP - 5236 PB - Copernicus Publ. CY - Göttingen ER -