A review of the fossil record of turtles of the clade Pan-Carettochelys

Turtles of the total clade Pan-Carettochelys have a relatively poor fossil record that extends from the Early Cretaceous. The clade is only found in Asia during the Cretaceous, but spreads to Europe and North America during the Eocene. Neogene finds are restricted to Europe, Africa and Australia, whereas the only surviving species, Carettochelys insculpta, lives in New Guinea and the Northern Territories of Australia. The ecology of fossil pan-carettochelyids appears similar to that of the extant C. insculpta, although more primitive representatives were likely less adapted to brackish water. Current phylogenies only recognize three internested clades: Pan- Carettochelys, Carettochelyidae and Carettochelyinae. A taxonomic review of the group concludes that of 25 named taxa, 13 are nomina valida, 7 are nomina invalida, 3 are nomina dubia, and 2 are nomina nuda

Broadband multi-wavelength properties of M87 during the 2017 Event Horizon Telescope campaign

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109Me. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.http://iopscience.iop.org/2041-8205am2022Physic

Broadband multi-wavelength properties of M87 during the 2017 Event Horizon Telescope campaign

High Energy AstrophysicsInstrumentatio

Verification of statistical-dynamical downscaling in the Alpine region

The statistical-dynamical downscaling procedure for global climate simulations (Frey-Buness et al. 1995) is verified for the greater Alpine region. This procedure links global and regional model simulations using statistics about large-scale weather types in order to derive the regional climate corresponding to a given global climate. A multi-year time series of global simulations or large-scale analyses is classified into a set of large-scale weather types. Regional model simulations are carried out once for each class. The model output fields are weighted with the frequencies of the corresponding weather type to give the regional climate. As downscaling procedures transmit uncertainties of the global climate simulation to the regional scale, the verification of the statistical-dynamical procedure is based on large-scale observational data, in our case on a decade of ECMWF-analyses. The downscaled results are compared with local observations of the same decade. The verification shows that the downscaling procedure is able to reproduce the basic patterns of the observed regional distributions of climatological parameters. However, some features are not captured. Especially, the regional distribution of precipitation in summer exhibits major deficiencies. Possible reasons for these deficiencies are discussed and an outlook is given to further improvements of the statistical-dynamical downscaling procedure. (orig.)17 refs.Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Statistisch-dynamische Regionalisierung auf der Basis einer Klassifikation synoptischer Entwicklungen

A nee statistical-dynamical method for downscaling global climate analyses or simulations is described. The method is based on the disaggregation of a multi-year time-series of large-scale data into multi-day episodes of a quasi-stationary circulation. The episodes are subsequently grouped into a defined number of classes. A regional model is used to simulate the evolution of weather during the most typical episode of each class. These simulations consider the effects of the regional topography. Finally, the regional model results are statistically weighted with the climatological frequencies of the respective circulation classes to eventually form regional climate patterns. The statistical-dynamical procedure is applied to large-scale analysis of the 13-year climate period 1981-1993. The ability of the new method is demonstrated with a regional precipitation climatology and SYNOP-station data from the Alpine region. The new statistical-dynamical downscaling method turns out to be an efficient alternative to the commonly used method of continuously nesting a regional model within a general circulation model. (orig.)Available from TIB Hannover: RN 437(98-16) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Klimavariabilitaet und Signalanalyse. Regionalisierung globaler Klimaaenderungen und Klimavariabilitaet Sachbericht

SIGLEAvailable from TIB Hannover: DtF QN1(74,35) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman