Why Is the Climate Forcing of Sulfate Aerosols So Uncertain?   总被引：2，自引：0，他引：2  

Hu Rongming  Serge Planton  Michel Déque  Pascal Marquet  Alain Braun 《大气科学进展》2001,18(6):1103-1120

l. IntroductionAlthough the aerosol has been recognized as an important factor which has innuence onthe past, present and future climate for a long time, it still has much uncertainty in assessingits climate forcing. The direct radiative forcing of sulfate aerosols has been estimated rangingfrom --0.3 W/ m2 to --0.9 W/ m2 in recent publications (Charlson et al., l992, Kiehl andBriegleb l993; Taylor and Penner 1994, Boucher and Anderson l995, Kieh1 and Rodhe l995;Chuang et al., l997, Penne…  相似文献   

Modelling landscape evolution on geological time scales: a new method based on irregular spatial discretization   总被引：5，自引：0，他引：5  

Jean Braun  & Malcolm Sambridge 《Basin Research》1997,9(1):27-52

We present simulations of large-scale landscape evolution on tectonic time scales obtained from a new numerical model which allows for arbitrary spatial discretization. The new method makes use of efficient algorithms from the field of computational geometry to compute the set of natural neighbours of any irregular distribution of points in a plane. The natural neighbours are used to solve geomorphic equations that include erosion/deposition by channelled flow and diffusion. The algorithm has great geometrical flexibility, which makes it possible to solve problems involving complex boundaries, radially symmetrical uplift functions and horizontal tectonic transport across strike-slip faults. The algorithm is also ideally suited for problems which require large variations in spatial discretization and/or self-adaptive meshing. We present a number of examples to illustrate the power of the new approach and its advantages over more 'classical' models based on regular (rectangular) discretization. We also demonstrate that the synthetic river networks and landscapes generated by the model obey the laws of network composition and have scaling properties similar to those of natural landscapes. Finally we explain how orographically controlled precipitation and flexural isostasy may be easily incorporated in the model without sacrificing efficiency.
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Geology,alteration, and lithogeochemistry of the Hood volcanogenic massive sulfide (VMS) deposits,Nunavut, Canada     

Hannah K. Mills  Stephen J. Piercey  Trish Toole 《Mineralium Deposita》2016,51(4):533-556

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Sedimentological records of the C.E. 1707 Hōei Nankai Trough tsunami in the Bungo Channel,southwestern Japan     

Hannah E. Baranes  Jonathan D. Woodruff  Davin J. Wallace  Kinuyo Kanamaru  Timothy L. Cook 《Natural Hazards》2016,84(2):1185-1205

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Interactive Knowledge Generation in Urban Green Building Transitions     

Bérénice Preller  Julia Affolderbach  Christian Schulz  Sebastian Fastenrath  Boris Braun 《The Professional geographer》2017,69(2):214-224

Knowledge coproduction between practitioners and scientists offers promising opportunities for the emerging research field of the geography of sustainability transitions. Drawing on experiences from an international research project on urban green building transitions, this article explores the potentials and challenges of interactive and collaborative knowledge generation methods in understanding sustainability transitions. Our results show that ongoing engagement with local experts and practitioners through interactive World Café workshops and follow-up exchanges allows for a better understanding of the research context and knowledge exchange to all participants involved in the research process.  相似文献   

Trans-Atlantic responses of Calanus finmarchicus populations to basin-scale forcing associated with the North Atlantic Oscillation     

C. H. Greene  A. J. Pershing  A. Conversi  B. Planque  C. Hannah  D. Sameoto  E. Head  P. C. Smith  P. C. Reid  J. Jossi  D. Mountain  M. C. Benfield  P. H. Wiebe  E. Durbin 《Progress in Oceanography》2003,58(2-4):301

Populations of the copepod species Calanus finmarchicus often dominate the springtime biomass and secondary production of shelf ecosystems throughout the North Atlantic Ocean. Recently, it has been hypothesised that interannual to interdecadal fluctuations observed in such populations are driven primarily by climate-associated changes in ocean circulation. Here, we compare evidence from the North Sea and Gulf of Maine/Western Scotian Shelf (GoM/WSS) linking fluctuations in C. finmarchicus abundance to changes in ocean circulation associated with the North Atlantic Oscillation (NAO). A particularly striking contrast emerges from this Trans-Atlantic comparison: whereas the North Sea C. finmarchicus population exhibits a negative correlation with the NAO index, the GoM/WSS population exhibits a more complex, positive association with the index. The physical processes underlying these contrasting population responses are discussed in the context of regional- to basin-scale circulation changes associated with the NAO.  相似文献   

An assessment model for the fate and environmental effects of offshore drilling mud discharges   总被引：1，自引：0，他引：1  

Charles G. Hannah  Adam Drozdowski  John Loder  Kee Muschenheim  Tim Milligan 《Estuarine, Coastal and Shelf Science》2006,70(4):577

The benthic boundary layer transport (bblt) model was developed to assess potential impact zones from drilling mud discharges from offshore oil and gas drilling. The model focuses on the drift, dispersion and concentration levels of the suspended fraction of the drilling mud fines in the benthic boundary layer with the assumption of a spatially homogeneous environment. The current version of the model includes a wave boundary layer, a breakup module for drilling mud flocs, a dose–response module for scallops, and a graphical user interface (GUI). The GUI was written in Java which makes the code largely platform independent. Simulations of suspended barite concentration near Sable Island on the Scotian Shelf during drilling in the fall of 1999 reproduce the very low concentrations (generally less than 1 μg L⁻¹) observed during the Environmental Effects Monitoring program. However, the simulations also exhibited concentrations in excess of the no-effects concentration for scallops (100 μg L⁻¹) prior to the sampling program. The model estimates that the potential impact on scallops in the vicinity of the drilling is a few days of lost growth over scales of a few kilometers.  相似文献   

Better must come: exiting homelessness in two global cities,by Matthew D. Marr     

Christine L. Jocoy  Hannah Zucherman 《Urban geography》2017,38(2):318-320

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Wind‐driven depth‐averaged circulation in Queen Charlotte Sound and Hecate Strait     

Charles G. Hannah  Paul H. LeBlond  William R. Crawford  W. Paul Budgell 《大气与海洋》2013,51(4):712-736

Abstract

We develop a wind‐driven depth‐averaged model of the circulation on the continental shelf around the Queen Charlotte Islands. The model captures a major feature of the winter current‐meter observations: a flow in Moresby Trough against the direction of the prevailing winds. Moresby Trough is a steep submarine canyon cutting across the shelf from the Pacific Ocean to the mainland. The flow patterns revealed by simulated drifters lead to four generalizations about the depth‐averaged, wind‐driven flow: (1) the flow is subject to strong topographic steering, (2) the exchange between Queen Charlotte Sound and the Pacific Ocean is limited to small regions near Cape St James and Cape Scott, (3) the exchange between Queen Charlotte Sound and Hecate Strait is controlled by Moresby Trough, and (4) the observed outflows past Cape St James are not explained by the dynamics of this model.  相似文献   

Moving beyond the catchment scale: Value and opportunities in large-scale hydrology to understand our changing world     

Daniel G. Kingston  Nicolas Massei  Bastien Dieppois  David M. Hannah  Andreas Hartmann  David A. Lavers  Jean-Philippe Vidal 《水文研究》2020,34(10):2292-2298

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