A simple three-dimensional canopy – planetary boundary layer simulation model for scalar concentrations and fluxes     

ANDREJ SOGACHEV  GENNADY V. MENZHULIN  MARTIN HEIMANN  JON LLOYD 《Tellus. Series B, Chemical and physical meteorology》2002,54(5):784-819

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A new validation scheme for the evaluation of multiparameter fields     

FRIEDRICH-WILHELM GERSTENGARBE  MARTIN KÜCKEN  PETER C. WERNER 《地球，A辑:动力气象学与海洋学》2005,57(1):35-42

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Simulation of atmospheric CO₂ over Europe and western Siberia using the regional scale model REMO     

ANNE CHEVILLARD  UTE KARSTENS  PHILIPPE CIAIS  SÉBASTIEN LAFONT  MARTIN HEIMANN 《Tellus. Series B, Chemical and physical meteorology》2002,54(5):872-894

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Palaeo-ice streams and the subglacial landscape mosaic of the North American mid-continental prairies     

MARTIN ROSS  JANET E. CAMPBELL  MICHEL PARENT  ROBERTA S. ADAMS 《Boreas: An International Journal of Quaternary Research》2009,38(3):421-439

The analysis of the glacial landscape of southern Saskatchewan (Canada) through multiple data sets (e.g. digital elevation model, till compositional data) has revealed previously unrecognized subglacial sediment–landform assemblages. A southwest-trending corridor of mega-scale till lineations (Maskwa corridor) bounded on each side by hummocky terrain extends from the Canadian Shield to southwestern Saskatchewan. This landform assemblage is clearly cross-cut by a broad south to southeast trending corridor (Buffalo corridor) consisting of subparallel curvilinear till ridges. The carbonate content of the surface till is spatially consistent within these assemblages, suggesting a strong sediment–landform relationship. The two corridors are interpreted as the product of palaeo-ice streams. The Maskwa palaeo-ice stream flowed up the regional slope and across preglacial valleys, indicating it was thick and stable. Narrow dispersal trains extending across as well as down-glacier from the Athabasca Basin suggest that the Maskwa palaeo-ice stream extended far into the ice sheet across contrasting shield and platform terrains. In comparison, the Buffalo palaeo-ice stream was thinner and largely controlled by subglacial geology and topography. Its catchments were located at the Canadian Shield boundary and the system was oriented along-slope. It experienced lateral shifts and it was fed by a network of tributaries. The glacial dynamics shift from the Maskwa to the Buffalo system occurred at about 13.5 ¹⁴C kyr BP. The Buffalo system later evolved into thin outlet lobes until final deglaciation of the area. The proposed model has implications for ice-sheet reconstruction and the assessment of till properties in the prairies and in similar terrains.  相似文献   

Spatial distribution and optical properties of Saharan dust observed by airborne high spectral resolution lidar during SAMUM 2006     

By MICHAEL ESSELBORN  MARTIN WIRTH  REAS FIX  BERNADETT WEINZIERL  KATHARINA RASP  MATTHIAS TESCHE  ANDREAS PETZOLD 《Tellus. Series B, Chemical and physical meteorology》2009,61(1):131-143

Airborne measurements of pure Saharan dust extinction and backscatter coefficients, the corresponding lidar ratio and the aerosol optical thickness (AOT) have been performed during the Saharan Mineral Dust Experiment 2006, with a high spectral resolution lidar. Dust layers were found to range from ground up to 4–6 km above sea level (asl). Maximum AOT values at 532 nm, encountered within these layers during the DLR Falcon research flights were 0.50–0.55. A significant horizontal variability of the AOT south of the High Atlas mountain range was observed even in cases of a well-mixed dust layer. High vertical variations of the dust lidar ratio of 38–50 sr were observed in cases of stratified dust layers. The variability of the lidar ratio was attributed to dust advection from different source regions. The aerosol depolarization ratio was about 30% at 532 nm during all measurements and showed only marginal vertical variations.  相似文献   

Extensive carbonate algal bioherms in upper Pleistocene saline lakes of the central Altiplano of Bolivia   总被引：1，自引：0，他引：1  

JEAN MARIE ROUCHY  MICHEL SERVANT†  MARC FOURNIER†  CHRISTIANE CAUSSE 《Sedimentology》1996,43(6):973-993

During the upper Pleistocene the Central Altiplano of Bolivia was repeatedly flooded by deep and extensive saline lakes in response to climatic fluctuations. Development of carbonate algal bioherms took place during at least three major periods of lacustrine highstands, discontinuously covering the 300-km-long and 100-km-wide lacustrine slopes and terraces up to an elevation of 100 m above the surface of the modern halite crust of Uyuni. Distribution, size and shape of the bioherms are diverse due to various factors, e.g. the nature and morphology of the substrate and the hydrodynamic conditions that prevailed during growth. On larger palaeoterraces, the build-ups coalesced to form platform-like carbonate accumulations. Although the morphologies closely resemble those induced by cyanobacteria, they were predominantly constructed by other plant communities, probably dominated by filamentous green algae. Cyanobacterial communities flourished in association with these plants, but they did not contribute significantly to the architecture of the bioherms; they participated to encrust the plant stems and algal bushes or to form thin laminated layers covering the build-ups. A prominent feature of some bioherms is their composite structure due to repeated algal growth during successive lacustrine episodes that were separated by subaerial exposures with moderate erosional effects. The build-ups located between 3660 and 3680 m elevation display up to three major parts: (1) a massive inner core formed during an early Minchin highstand, before 40 ka; (2) a large peripheral envelope deposited at about 40 ka (late Minchin) and (3) a thinner outermost crust formed during a late glacial event. Lake level dropped during interlacustrine stages, sometimes leading to desiccation and deposition of salt layers in the deepest parts of the system, i.e. the present-day salar of Uyuni.  相似文献   

Some Implications of the Intemationalisation of Commercial Capital for New Zealand     

MARTIN PERRY 《New Zealand geographer》1991,47(1):26-31

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Till stratigraphy and ice movements in eastern Overijssel, The Netherlands     

SJOERD J. KLUIVING  MARTIN RAPPOL  DICK VAN DER WATEREN 《Boreas: An International Journal of Quaternary Research》1991,20(3):193-205

A three–till section in eastern Overijssel, eastern Netherlands, represents the most complete till sequence of the Older Saalian glaciation presently known from The Netherlands and adjacent Germany. On the basis of structural analyses, four different glacial events within one continuous glacial cover can be distinguished: (1) deposition of till 1 (lowest till) by ice probably moving in a southerly direction, (2) glaciotectonic dislocation of till 1 under a compressive strain regime acting towards the west, (3) deposition of till 2 by ice moving in a westerly direction, and (4) deposition of till 3 by southeasterly moving ice. During deposition of tills 2 and 3, the underlying older tills were subjected to a strong extensional tectonic regimc, leading among other things to the development of characteristic sheath folds. On the basis of directional and compositional characteristics, the three tills can be correlated with the till stratigraphy of the northern Netherlands.  相似文献   

Modelling the long-range transport of ²²²Rn to subantarctic and antarctic areas     

MARTIN HEIMANN†  PATRICK MONFRAY†‡  GEORGES POLIAN‡ 《Tellus. Series B, Chemical and physical meteorology》1990,42(1):83-99

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Evolution of a small intraplate basaltic lava field: Jerrabattgulla Creek,upper Shoalhaven River catchment,southeast New South Wales     

I. C. Roach†  S. M. Hill†  A. C. Lewis† 《Australian Journal of Earth Sciences》2013,60(8):1049-1061

The Jerrabattgulla Creek basalts are in the upper catchment of the Shoalhaven River of southeastern New South Wales. The basalts erupted into a narrow, north-draining valley and modified the local drainage system, re-routing the paleo-Jerrabattgulla Creek, preserving a series of sub-basaltic quartzose gravels with silcretes in the paleovalley. The paleovalley indicates that a north-flowing drainage existed in this place in the Miocene. The high-relief, narrow valley has preserved a volcanic stratigraphy allowing the magmatic evolution of this small lava field to be determined. The lavas have a large compositional range from olivine nephelinite through to quartz tholeiite, which is unusual in such a small lava field. They represent three distinct magma batches, most likely from an amphibole–apatite metasomatised sub-continental lithospheric mantle, and underwent fractional crystallisation of olivine, clinopyroxene and plagioclase and assimilated upper crust. The lava field underwent temporal change from dominantly alkaline, to mixed alkaline and subalkaline, to dominantly alkaline magmatism over the course of its evolution.  相似文献