A Double-Canyon Radiation Scheme for Multi-Layer Urban Canopy Models   总被引：1，自引：0，他引：1  

Sebastian Schubert  Susanne Grossman-Clarke  Alberto Martilli 《Boundary-Layer Meteorology》2012,145(3):439-468

We develop a double-canyon radiation scheme (DCEP) for urban canopy models embedded in mesoscale numerical models based on the Building Effect Parametrization (BEP). The new scheme calculates the incoming and outgoing longwave and shortwave radiation for roof, wall and ground surfaces for an urban street canyon characterized by its street and building width, canyon length, and the building height distribution. The scheme introduces the radiative interaction of two neighbouring urban canyons allowing the full inclusion of roofs into the radiation exchange both inside the canyon and with the sky. In contrast to BEP, we also treat direct and diffuse shortwave radiation from the sky independently, thus allowing calculation of the effective parameters representing the urban diffuse and direct shortwave radiation budget inside the mesoscale model. Furthermore, we close the energy balance of incoming longwave and diffuse shortwave radiation from the sky, so that the new scheme is physically more consistent than the BEP scheme. Sensitivity tests show that these modifications are important for urban regions with a large variety of building heights. The evaluation against data from the Basel Urban Boundary Layer Experiment indicates a good performance of the DCEP when coupled with the regional weather and climate model COSMO-CLM.  相似文献   

The STAGES view of red spirals and dusty red galaxies: mass-dependent quenching of star formation in cluster infall     

Christian Wolf  Alfonso Aragón-Salamanca  Michael Balogh  Marco Barden  Eric F. Bell  Meghan E. Gray  Chien Y. Peng  David Bacon  Fabio D. Barazza  Asmus Böhm  John A. R. Caldwell  Anna Gallazzi  Boris Häußler  Catherine Heymans  Knud Jahnke  Shardha Jogee  Eelco van Kampen  Kyle Lane  Daniel H. McIntosh  Klaus Meisenheimer  Casey Papovich  Sebastian F. Sánchez  y Taylor  Lutz Wisotzki  Xianzhong Zheng 《Monthly notices of the Royal Astronomical Society》2009,393(4):1302-1323

We investigate the properties of optically passive spirals and dusty red galaxies in the A901/2 cluster complex at redshift ∼0.17 using rest-frame near-ultraviolet–optical spectral energy distributions, 24-μm infrared data and Hubble Space Telescope morphologies from the STAGES data set. The cluster sample is based on COMBO-17 redshifts with an rms precision of  σ _cz ≈ 2000 km s⁻¹  . We find that 'dusty red galaxies' and 'optically passive spirals' in A901/2 are largely the same phenomenon, and that they form stars at a substantial rate, which is only four times lower than that in blue spirals at fixed mass. This star formation is more obscured than in blue galaxies and its optical signatures are weak. They appear predominantly in the stellar mass range of  log  M _*/M_⊙=[10, 11]  where they constitute over half of the star-forming galaxies in the cluster; they are thus a vital ingredient for understanding the overall picture of star formation quenching in clusters. We find that the mean specific star formation rate (SFR) of star-forming galaxies in the cluster is clearly lower than in the field, in contrast to the specific SFR properties of blue galaxies alone, which appear similar in cluster and field. Such a rich red spiral population is best explained if quenching is a slow process and morphological transformation is delayed even more. At  log  M _*/M_⊙ < 10  , such galaxies are rare, suggesting that their quenching is fast and accompanied by morphological change. We note that edge-on spirals play a minor role; despite being dust reddened they form only a small fraction of spirals independent of environment.  相似文献   

Correction to: Sea-state contributions to sea-level variability in the European Seas     

Bonaduce  Antonio  Staneva  Joanna  Grayek  Sebastian  Bidlot  Jean-Raymond  Breivik  Øyvind 《Ocean Dynamics》2021,71(2):279-279

Ocean Dynamics - A Correction to this paper has been published: https://doi.org/10.1007/s10236-020-01434-9  相似文献   

Detecting protoplanets with ALMA     

Sebastian Wolf 《Astrophysics and Space Science》2008,313(1-3):109-112

Theoretical investigations show that planet-disk interactions cause structures in circumstellar disks, which are usually much larger in size than the planet itself and thus more easily detectable. The specific result of planet-disk interactions depends on the evolutionary stage of the disk. Exemplary signatures of planets embedded in disks are gaps and spiral density waves in the case of young, gas-rich protoplanetary disks and characteristic asymmetric density patterns in debris disks. Numerical simulations convincingly demonstrate that high-resolution imaging performed with observational facilities which are already available or will become available in the near future will allow to trace these “fingerprints” of planets in protoplanetary and debris disks. These observations will provide a deep insight into specific phases of the formation and early evolution of planets in circumstellar disks. In this context, the Atacama Large Millimeter Array (ALMA) will play a crucial role by allowing to trace features in disks which are indicative for various stages of the formation and early evolution of planets in circumstellar disks.  相似文献   

The dark matter environment of the Abell 901/902 supercluster: a weak lensing analysis of the HST STAGES survey     

Catherine Heymans  Meghan E. Gray  Chien Y. Peng  Ludovic Van Waerbeke  Eric F. Bell  Christian Wolf  David Bacon  Michael Balogh  Fabio D. Barazza  Marco Barden  Asmus Böhm  John A. R. Caldwell  Boris Häußler  Knud Jahnke  Shardha Jogee  Eelco van Kampen  Kyle Lane  Daniel H. McIntosh  Klaus Meisenheimer  Yannick Mellier  Sebastian F. Sánchez  y N. Taylor  Lutz Wisotzki  Xianzhong Zheng 《Monthly notices of the Royal Astronomical Society》2008,385(3):1431-1442

We present a high-resolution dark matter reconstruction of the   z = 0.165  Abell 901/902 supercluster from a weak lensing analysis of the Hubble Space Telescope STAGES survey. We detect the four main structures of the supercluster at high significance, resolving substructure within and between the clusters. We find that the distribution of dark matter is well traced by the cluster galaxies, with the brightest cluster galaxies marking out the strongest peaks in the dark matter distribution. We also find a significant extension of the dark matter distribution of Abell 901a in the direction of an infalling X-ray group Abell 901α. We present mass, mass-to-light and mass-to-stellar mass ratio measurements of the structures and substructures that we detect. We find no evidence for variation of the mass-to-light and mass-to-stellar mass ratio between the different clusters. We compare our space-based lensing analysis with an earlier ground-based lensing analysis of the supercluster to demonstrate the importance of space-based imaging for future weak lensing dark matter 'observations'.  相似文献   

Monitoring of the nano-structure response of natural clay under mechanical perturbation using small angle X-ray scattering and digital image correlation     

Birmpilis  Georgios  Hall  Stephen A.  Lages  Sebastian  Dijkstra  Jelke 《Acta Geotechnica》2019,14(6):1965-1975

Acta Geotechnica - This paper introduces a new experimental method to monitor the evolving intra-particle, nanometre-scale response during hydro-mechanical tests on undisturbed wet clay samples...  相似文献   

High Resolution Köppen‐Geiger Classifications of Paleoclimate Simulations          下载免费PDF全文

Christian Willmes  Daniel Becker  Sebastian Brocks  Christoph Hütt  Georg Bareth 《Transactions in GIS》2017,21(1):57-73

The development and application of an algorithm to compute Köppen‐Geiger climate classifications from the Coupled Model Intercomparison Project (CMIP) and Paleo Model Intercomparison Project (PMIP) climate model simulation data is described in this study. The classification algorithm was applied to data from the PMIP III paleoclimate experiments for the Last Glacial Maximum, 21k years before present (yBP), Mid‐Holocene (6k yBP) and the Pre‐Industrial (0k yBP, control run) time slices. To infer detailed classification maps, the simulation datasets were interpolated to a higher resolution. The classification method presented is based on the application of Open Source Software, and the implementation is described with attention to detail. The source code and the exact input data sets as well as the resulting data sets are provided to enable the application of the presented approach.  相似文献   

The shape of the blue/UV continuum of B3-VLA radio quasars: dependence on redshift, blue/UV luminosity and radio power     

Ruth Carballo  J. Ignacio González-Serrano  Chris R. Benn  Sebastian F. Sánchez  Mario Vigotti 《Monthly notices of the Royal Astronomical Society》1999,306(1):137-152

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A dynamic 2DH flocculation model for coastal domains     

Escobar  Sebastian  Bi  Qilong  Fettweis  Michael  Wongsoredjo  Samor  Monbaliu  Jaak  Toorman  Erik 《Ocean Dynamics》2023,73(6):333-358

Ocean Dynamics - A dynamic two-dimensional depth-averaged (2DH) parameterization for flocculation of cohesive sediments is proposed based on the kinetic model by Winterwerp (J Hydraul Res...  相似文献   

Cascading ocean basins: numerical simulations of the circulation and interbasin exchange in the Azov-Black-Marmara-Mediterranean Seas system     

Emil Vassilev Stanev  Sebastian Grashorn  Yinglong Joseph Zhang 《Ocean Dynamics》2017,67(8):1003-1025

In this paper, we use the unstructured grid model SCHISM to simulate the thermohydrodynamics in a chain of baroclinic, interconnected basins. The model shows a good skill in simulating the horizontal circulation and vertical profiles of temperature, salinity, and currents. The magnitude and phases of the seasonal changes of circulation are consistent with earlier observations. Among the mesoscale and subbasin-scale circulation features that are realistically simulated are the anticyclonic coastal eddies, the Sebastopol and Batumi eddies, the Marmara Sea outflow around the southern coast of the Limnos Island, and the pathway of the cold water originating from the shelf. The superiority of the simulations compared to earlier numerical studies is demonstrated with the example of model capabilities to resolve the strait dynamics, gravity currents originating from the straits, high-salinity bottom layer on the shallow shelf, as well as the multiple intrusions from the Bosporus Strait down to 700 m depth. The warm temperature intrusions from the strait produce the warm water mass in the intermediate layers of the Black Sea. One novel result is that the seasonal intensification of circulation affects the interbasin exchange, thus allowing us to formulate the concept of circulation-controlled interbasin exchange. To the best of our knowledge, the present numerical simulations, for the first time, suggest that the sea level in the interior part of the Black Sea can be lower than the sea level in the Marmara Sea and even in some parts of the Aegean Sea. The comparison with observations shows that the timings and magnitude of exchange flows are also realistically simulated, along with the blocking events. The short-term variability of the strait transports is largely controlled by the anomalies of wind. The simulations demonstrate the crucial role of the narrow and shallow strait of Bosporus in separating the two pairs of basins: Aegean-Marmara Seas from one side and Azov-Black Seas from the other side. The straits of Kerch and Dardanelles provide sufficient interbasin connectivity that prevents large phase lags of the sea levels in the neighboring basins. The two-layer flows in the three straits considered here show different dependencies upon the net transport, and the spatial variability of this dependence is also quite pronounced. We show that the blocking of the surface flow can occur at different net transports, thus casting doubt on a previous approach of using simple relationships to prescribe (steady) outflow and inflow. Specific attention is paid to the role of synoptic atmospheric forcing for the basin-wide circulation and redistribution of mass in the Black Sea. An important controlling process is the propagation of coastal waves. One major conclusion from this research is that modeling the individual basins separately could result in large inaccuracies because of the critical importance of the cascading character of these interconnected basins.  相似文献