Improved regional scale processes reflected in projected hydrological changes over large European catchments     

Stefan Hagemann  Holger Göttel  Daniela Jacob  Philip Lorenz  Erich Roeckner 《Climate Dynamics》2009,32(6):767-781

For the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC), the recent version of the coupled atmosphere/ocean general circulation model (GCM) of the Max Planck Institute for Meteorology has been used to conduct an ensemble of transient climate simulations These simulations comprise three control simulations for the past century covering the period 1860–2000, and nine simulations for the future climate (2001–2100) using greenhouse gas (GHG) and aerosol concentrations according to the three IPCC scenarios B1, A1B and A2. For each scenario three simulations were performed. The global simulations were dynamically downscaled over Europe using the regional climate model (RCM) REMO at 0.44° horizontal resolution (about 50 km), whereas the physics packages of the GCM and RCM largely agree. The regional simulations comprise the three control simulations (1950–2000), the three A1B simulations and one simulation for B1 as well as for A2 (2001–2100). In our study we concentrate on the climate change signals in the hydrological cycle and the 2 m temperature by comparing the mean projected climate at the end of the twenty-first century (2071–2100) to a control period representing current climate (1961–1990). The robustness of the climate change signal projected by the GCM and RCM is analysed focussing on the large European catchments of Baltic Sea (land only), Danube and Rhine. In this respect, a robust climate change signal designates a projected change that sticks out of the noise of natural climate variability. Catchments and seasons are identified where the climate change signal in the components of the hydrological cycle is robust, and where this signal has a larger uncertainty. Notable differences in the robustness of the climate change signals between the GCM and RCM simulations are related to a stronger warming projected by the GCM in the winter over the Baltic Sea catchment and in the summer over the Danube and Rhine catchments. Our results indicate that the main explanation for these differences is that the finer resolution of the RCM leads to a better representation of local scale processes at the surface that feed back to the atmosphere, i.e. an improved representation of the land sea contrast and related moisture transport processes over the Baltic Sea catchment, and an improved representation of soil moisture feedbacks to the atmosphere over the Danube and Rhine catchments.  相似文献   

Holistic, adaptive management of the terrestrial carbon cycle at local and regional scales   总被引：2，自引：0，他引：2  

Petra Tschakert  Elisabeth Huber-Sannwald  Dennis S. Ojima  Michael R. Raupach  Erich Schienke 《Global Environmental Change》2008,18(1):128-141

Actions to manage carbon dioxide (and other greenhouse gas) emissions at regional and local scales take place amid multiple requirements, participants, and agents. To address and solve tensions that emerge from diverse objectives and stakeholder needs, participatory decision processes and information tools are required. This paper explores how regional carbon budget information can contribute to the broader goal of holistic, adaptive regional development. We sketch the characteristics of a novel integrative framework for adaptive carbon management in the context of multiple criteria. An ex-post case study on carbon mitigation from Chiapas, Mexico, demonstrates challenges and trade-offs in a real-world setting.  相似文献   

Rain and dewdrops on titan based on in situ imaging     

Erich Karkoschka  Martin G. Tomasko 《Icarus》2009,199(2):442-1417

The Descent Imager/Spectral Radiometer (DISR) of the Huygens probe was in an excellent position to view aspects of rain as it descended through Titan's atmosphere. Rain may play an important part of the methane cycle on Titan, similar to the water cycle on Earth, but rain has only been indirectly inferred in previous studies. DISR detected two dark atmospheric layers at 11 and 21 km altitude, which can be explained by a local increase in aerosol size by about 5-10%. These size variations are far smaller than those in rain clouds, where droplets grow some 1000-fold. No image revealed a rainbow, which implies that the optical depth of raindrops was less than ∼0.0002/km. This upper limit excludes rain and constrains drizzle to extremely small rates of less than 0.0001 mm/h. However, a constant drizzle of that rate over several years would clear the troposphere of aerosols faster than it can be replenished by stratospheric aerosols. Hence, either the average yearly drizzle rate near the equator was even less (<0.1 mm/yr), or the observed aerosols came from somewhere else. The implied dry environment is consistent with ground-based imaging showing a lack of low-latitude clouds during the years before the Huygens descent. Features imaged on Titan's surface after landing, which might be interpreted as raindrop splashes, were not real, except for one case. This feature was a dewdrop falling from the outermost baffle of the DISR instrument. It can be explained by warm, methane-moist air rising along the bottom of the probe and condensing onto the cold baffle.  相似文献   

Stratigraphic and geochemical evidence for the depositional environment of the early archaean isua supracrustal belt,southern west greenland     

Allen P. Nutman  Jan H. Allaart  David Bridgwater  Erich Dimroth  Minik Rosing 《Precambrian Research》1984,25(4):365-396

The highly deformed c. 3800 Ma Isua supracrustal belt is a fragment of a more extensive Early Archaean sedimentary and volcanic succession intruded by and tectonically intercalated with tonalitic and granitic Amftsoq gneisses in the period 3800-3600 Ma. The supracrustal rocks recrystallised under amphibolite facies conditions between 3800 and 3600 Ma, in the Late Archaean and locally at c. 1800 Ma. Layered sequences of rock of sedimentary and probable volcanic origin form over 50% of the belt. Bodies of high MgAl basic rocks and ultramafic rocks were intruded into the layered sequences prior to isoclinal folding and intrusion of Amitsoq gneisses. The layered rocks which are < 1 km thick are divided into two sequences, that are in faulted contact with each other. The way-up of these sequences has been determined from facing-directions of locally-preserved graded layering in felsic metasediments at several localities. The overall upwards change in sedimentary succession is interpreted as showing change from dominantly basic to dominantly felsic volcanism which provided the major clastic component of the sediments. Clastic sedimentation took place against a background of chemical sedimentation, shown by interlayers of banded iron formation, metachert and calc-silicate rocks throughout the sequences. The felsic rocks locally preserve graded bedding and possible conglomerate structures, indicating deposition from turbidite flows and possibly as debris flows. Nodules in the felsic rocks contain structures interpreted as fiammé. There is an irregular enrichment in K₂O/Na₂O in many of the felsic rocks at constant SiO₂ and Al₂O₃ content, interpreted as owing to alteration of original andesitic to dacitic volcanic rocks. Banded iron formations locally contain conglomeratic structures suggesting sedimentary reworking, possibly under shallow water conditions. Lithological and geochemical characters of the clastic components of the supracrustal sequences are consistent with derivation from felsic and basic volcanic rocks and do not require a continental source.  相似文献   

Colouration Phenomena of Mediterranean Blennies (Pisces,Blenniidae)     

Erich F. Abel 《Marine Ecology》1993,14(4):291-312

Abstract. The blennies of the Mediterranean Sea were observed in nature by snorkeling and SCUBA diving. Particular attention was paid to their changeable basic patterns and colouring alternations as effected by ecological and ethological factors. Additionally, the tendency for colour change was tested in differently coloured tanks. These experiments failed to demonstrate the striking adaptations seen in the natural environment, except for a remarkable reaction to black and white. The summary of all known reports is supported by colour illustrations; the problems of the colouring alternations are discussed.  相似文献   

Atmospheric deposition of cadmium in the northeastern USA     

Stephen A. Norton  Tiffany Wilson  Michael Handley  Erich C. Osterberg 《Applied Geochemistry》2007

Lake sediment cores, dated by ²¹⁰Pb, were collected from Spectacle Pond (SP), Massachusetts, and Side Pistol Lake (SPL) and Sargent Mountain Pond (SMP), Maine, USA. SP is a kettle seepage lake in granitic sand and gravel. SMP is a drainage pond on granite with little soil in the small watershed. SPL is a drainage lake in granitic till. The three cores were analyzed for total Cd. For SP and SMP, maximum concentrations of 1.7 and 3.9 mg/kg, four and eight times background concentrations, respectively, occur in the late 1960s. Accumulation rates reach maximum values concurrently with concentration and are 0.054 and 0.016 μg/cm²/a, more than 10 times background. Concentration and accumulation rate age relationships in SMP and SP are similar for background values, timing and magnitude of increase to peak values, and the decrease nearly to background values since about 1975. The chemical response to decreased atmospheric deposition lags in SPL sediment. Kettle-like lakes more clearly indicate changes in atmospheric deposition than drainage lakes.  相似文献   

On the natural variability of the pre-industrial European climate     

Lennart Bengtsson  Kevin I. Hodges  Erich Roeckner  Renate Brokopf 《Climate Dynamics》2006,27(7-8):743-760

We suggest that climate variability in Europe for the “pre-industrial” period 1500–1900 is fundamentally a consequence of internal fluctuations of the climate system. This is because a model simulation, using fixed pre-industrial forcing, in several important aspects is consistent with recent observational reconstructions at high temporal resolution. This includes extreme warm and cold seasonal events as well as different measures of the decadal to multi-decadal variance. Significant trends of 50-year duration can be seen in the model simulation. While the global temperature is highly correlated with ENSO (El Nino- Southern Oscillation), European seasonal temperature is only weakly correlated with the global temperature broadly consistent with data from ERA-40 reanalyses. Seasonal temperature anomalies of the European land area are largely controlled by the position of the North Atlantic storm tracks. We believe the result is highly relevant for the interpretation of past observational records suggesting that the effect of external forcing appears to be of secondary importance. That variations in the solar irradiation could have been a credible cause of climate variations during the last centuries, as suggested in some previous studies, is presumably due to the fact that the models used in these studies may have underestimated the internal variability of the climate. The general interpretation from this study is that the past climate is just one of many possible realizations and thus in many respects not reproducible in its time evolution with a general circulation model but only reproducible in a statistical sense.  相似文献   

Book reviews     

Laura Sigg  Erich Schmidt Verlag 《Aquatic Sciences - Research Across Boundaries》1989,51(2):179-180

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Relief-Fährten am Winterstrand der Insel Usedom     

Erich Wasmund 《International Journal of Earth Sciences》1936,27(6):492-498

Zusammenfassung Es werden vom winterlichen pommerschen Flachstrand menschliche Relieffährten beschrieben, deren Erhöhung über Strandflächenniveau mit Tieffrieren der Eindruckstellen durch Druck, Regelation usw., und nachträgliches Herauspräparieren der ursprünglichen Hohlform durch Abtragungsvorgänge erklärt wird. Ihre Bedeutung für die Paläontologie (Chirotherienspuren) wird erörtert.  相似文献   

Die Regionalmetamorphose im Altvatergebirge     

Erich Bederke 《International Journal of Earth Sciences》1935,26(1-2):108-124

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