Circulation dynamics and its influence on European and Mediterranean January–April climate over the past half millennium: results and insights from instrumental data, documentary evidence and coupled climate models     

J. Luterbacher  S. J. Koenig  J. Franke  G. van der Schrier  E. Zorita  A. Moberg  J. Jacobeit  P. M. Della-Marta  M. Küttel  E. Xoplaki  D. Wheeler  T. Rutishauser  M. Stössel  H. Wanner  R. Brázdil  P. Dobrovolný  D. Camuffo  C. Bertolin  A. van Engelen  F. J. Gonzalez-Rouco  R. Wilson  C. Pfister  D. Limanówka  Ø. Nordli  L. Leijonhufvud  J. Söderberg  R. Allan  M. Barriendos  Rüdiger Glaser  D. Riemann  Z. Hao  C. S. Zerefos 《Climatic change》2010,101(1-2):201-234

We use long instrumental temperature series together with available field reconstructions of sea-level pressure (SLP) and three-dimensional climate model simulations to analyze relations between temperature anomalies and atmospheric circulation patterns over much of Europe and the Mediterranean for the late winter/early spring (January–April, JFMA) season. A Canonical Correlation Analysis (CCA) investigates interannual to interdecadal covariability between a new gridded SLP field reconstruction and seven long instrumental temperature series covering the past 250 years. We then present and discuss prominent atmospheric circulation patterns related to anomalous warm and cold JFMA conditions within different European areas spanning the period 1760–2007. Next, using a data assimilation technique, we link gridded SLP data with a climate model (EC-Bilt-Clio) for a better dynamical understanding of the relationship between large scale circulation and European climate. We thus present an alternative approach to reconstruct climate for the pre-instrumental period based on the assimilated model simulations. Furthermore, we present an independent method to extend the dynamic circulation analysis for anomalously cold European JFMA conditions back to the sixteenth century. To this end, we use documentary records that are spatially representative for the long instrumental records and derive, through modern analogs, large-scale SLP, surface temperature and precipitation fields. The skill of the analog method is tested in the virtual world of two three-dimensional climate simulations (ECHO-G and HadCM3). This endeavor offers new possibilities to both constrain climate model into a reconstruction mode (through the assimilation approach) and to better asses documentary data in a quantitative way.  相似文献   

The importance of ship log data: reconstructing North Atlantic, European and Mediterranean sea level pressure fields back to 1750     

M. Küttel  E. Xoplaki  D. Gallego  J. Luterbacher  R. García-Herrera  R. Allan  M. Barriendos  P. D. Jones  D. Wheeler  H. Wanner 《Climate Dynamics》2010,34(7-8):1115-1128

Local to regional climate anomalies are to a large extent determined by the state of the atmospheric circulation. The knowledge of large-scale sea level pressure (SLP) variations in former times is therefore crucial when addressing past climate changes across Europe and the Mediterranean. However, currently available SLP reconstructions lack data from the ocean, particularly in the pre-1850 period. Here we present a new statistically-derived 5° × 5° resolved gridded seasonal SLP dataset covering the eastern North Atlantic, Europe and the Mediterranean area (40°W–50°E; 20°N–70°N) back to 1750 using terrestrial instrumental pressure series and marine wind information from ship logbooks. For the period 1750–1850, the new SLP reconstruction provides a more accurate representation of the strength of the winter westerlies as well as the location and variability of the Azores High than currently available multiproxy pressure field reconstructions. These findings strongly support the potential of ship logbooks as an important source to determine past circulation variations especially for the pre-1850 period. This new dataset can be further used for dynamical studies relating large-scale atmospheric circulation to temperature and precipitation variability over the Mediterranean and Eurasia, for the comparison with outputs from GCMs as well as for detection and attribution studies.  相似文献   

Significance of particle interaction to the modelling of cohesive sediment transport in rivers     

Heinz Bungartz  Susanne C. Wanner 《水文研究》2004,18(9):1685-1702

Aggregation processes of fine sediments have rarely been integrated in numerical simulations of cohesive sediment transport in riverine systems. These processes, however, can significantly alter the hydrodynamic characteristics of suspended particulate matter (SPM), modifying the particle settling velocity, which is one of the most important parameters in modelling suspended sediment dynamics. The present paper presents data from field measurements and an approach to integrate particle aggregation in a hydrodynamic sediment transport model. The aggregation term used represents the interaction of multiple sediment classes (fractions) with corresponding multiple deposition behaviour. The k–ε–turbulence model was used to calculate the coefficient of vertical turbulent mixing needed for the two‐dimensional vertical‐plane simulations. The model has been applied to transport and deposition of tracer particles and natural SPM in a lake‐outlet lowland river (Spree River, Germany). The results of simulations were evaluated by comparison with field data obtained for two levels of river discharge. Experimental data for both discharge levels showed that under the prevailing uniform hydraulic conditions along the river reach, the settling velocity distribution did not change significantly downstream, whereas the amount of SPM declined. It was also shown that higher flow velocities (higher fluid shear) resulted in higher proportions of fast settling SPM fractions. We conclude that in accordance with the respective prevailing turbulence structures, typical aggregation mechanisms occur that continuously generate similar distribution patterns, including particles that settle toward the river bed and thus mainly contribute to the observed decline in the total SPM concentration. In order to determine time‐scales of aggregation and related mass fluxes between the settling velocity fractions, results of model simulations were fitted to experimental data for total SPM concentration and of settling velocity frequency distributions. The comparison with simulations for the case of non‐interacting fractions clearly demonstrated the practical significance of particle interaction for a more realistic modelling of cohesive sediment and contaminant transport. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Benchmarking the simulation of Cr isotope fractionation     

Christoph Wanner  Jennifer L. Druhan  Richard T. Amos  Peter Alt-Epping  Carl I. Steefel 《Computational Geosciences》2015,19(3):497-521

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Bücher- und Zeitschriftenschau     

Wanner  St.  Wilckens  Salomon 《International Journal of Earth Sciences》1927,18(3):237-239

Ohne Zusammenfassung  相似文献   

Curt Alfons Haniel     

Joh Wanner 《International Journal of Earth Sciences》1915,6(4-6):333-335

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Bericht über die Erste Tagung der Europäischen Seismologischen Kommission,Stuttgart 22.–27. September 1952     

E. Wanner 《Pure and Applied Geophysics》1952,23(1):223-231

Ohne Zusammenfassung  相似文献   

Die Arbeiten der Deutschen Island-Expedition 1938     

Oskar Niemczyk 《International Journal of Earth Sciences》1939,30(3):312-314

Ohne Zusammenfassung  相似文献   

Erdbebengeräusche     

Dr. E. Wanner 《Pure and Applied Geophysics》1948,12(3-4):127-129

Summary During the year 1946 the seismic activity in the ?Wallis? (Switzerland) was very high. A series of aftershocks has been registrated in the epicentre. At the same time the acoustic phenomenon accompanving the shocks has been observed directly. The different shocks could be classified in two types. The shocks which began as an eyplosion had all a very steep first wavefront (Fig. 2). The shocks which produced the same noise as an approaching heavy car had a very feeble first phase (Fig. 1).

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Résumé L'année 1946 fut une période séismique très active dans le Valais. On eut l'occasion d'observer une grande série de répliques dans l'épicentre avec un séismographe transportable. Les phénomènes acoustiques accompagnant ces secousses et observés directement, sont comparés avec les enregistrements séismographiques. Les secousses se manifestant comme eyplosion ont des enregistrements séismiques très typiques. Le front de la première onde des secousses était très raide (Fig. 2), tandis que les secousses dont le bruit émis ressemblait à une voiture roulante ont eu des précurseurs faibles (Fig. 1).

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Zur Altersfrage des oberjurassischen Aptychenkalkes im Balderschwanger Klippengebiet     

Joh Wanner 《International Journal of Earth Sciences》1928,18(6):455-456

Ohne Zusammenfassung  相似文献