An HWRF-based ensemble assessment of the land surface feedback on the post-landfall intensification of Tropical Storm Fay (2008)     

Monica Laureano Bozeman  Dev Niyogi  S. Gopalakrishnan  Frank D. Marks Jr.  Xuejin Zhang  Vijay Tallapragada 《Natural Hazards》2012,63(3):1543-1571

While tropical cyclones (TCs) usually decay after landfall, Tropical Storm Fay (2008) initially developed a storm central eye over South Florida by anomalous intensification overland. Unique to the Florida peninsula are Lake Okeechobee and the Everglades, which may have provided a surface feedback as the TC tracked near these features around the time of peak intensity. Analysis is done with the use of an ensemble model-based approach with the Developmental Testbed Center (DTC) version of the Hurricane WRF (HWRF) model using an outer domain and a storm-centered moving nest with 27- and 9-km grid spacing, respectively. Choice of land surface parameterization and small-scale surface features may influence TC structure, dictate the rate of TC decay, and even the anomalous intensification after landfall in model experiments. Results indicate that the HWRF model track and intensity forecasts are sensitive to three features in the model framework: land surface parameterization, initial boundary conditions, and the choice of planetary boundary layer (PBL) scheme. Land surface parameterizations such as the Geophysical Fluid Dynamics Laboratory (GFDL) Slab and Noah land surface models (LSMs) dominate the changes in storm track, while initial conditions and PBL schemes cause the largest changes in the TC intensity overland. Land surface heterogeneity in Florida from removing surface features in model simulations shows a small role in the forecast intensity change with no substantial alterations to TC track.  相似文献   

Application of portable X-ray fluorescence analyses to metabasalt stratigraphy,Plutonic Gold Mine,Western Australia     

Michael F. Gazley  Julie K. Vry  Ettienne du Plessis  Monica R. Handler 《Journal of Geochemical Exploration》2011

Stratigraphy, structure and host-rock chemistry are dominant controls on the location of Au in Archaean greenstone-hosted Au deposits, but the stratigraphy in such deposits is seldom obvious due to the monotonous nature of the host rocks or pervasive alteration associated with Au mineralisation. Portable, hand-held, X-ray fluorescence (pXRF) spectrometry provides a method to rapidly collect large amounts of whole-rock geochemical data that can yield new insights into both stratigraphy and Au localisation. Here we present results of pXRF analyses of samples from a representative section through Au-mineralised amphibolite-facies metabasaltic rocks at Plutonic Gold Mine, Western Australia. These data illustrate a geochemical stratigraphy in which individual lava flows can be identified on the basis of element concentrations. The most evolved basalts are at the structural base of the succession, and the least evolved at the top of the sequence, confirming previous geochemical interpretations and textural evidence that the sequence is overturned, and demonstrating for the first time that the presented section does not involve significant structural repetition. In conjunction with Au assay data, the pXRF data reveal that Au commonly occurs along basalt flow boundaries. The elemental concentration data clearly demonstrates for the first time the stratigraphic control on Au mineralisation that is not readily apparent at the macroscopic level. The methods described in this paper are readily applied, and have the potential to enhance the understanding of otherwise unclear stratigraphy and its control on mineralisation in many different types of deposits worldwide.  相似文献   

Stable isotope analysis of carbon and nitrogen in angrites     

F. A. J. Abernethy  A. B. Verchovsky  N. A. Starkey  M. Anand  I. A. Franchi  Monica M. Grady 《Meteoritics & planetary science》2013,48(9):1590-1606

Angrites are a small group of ancient basaltic achondrites, notable for their unusual chemistry and extreme volatile depletion. No comprehensive study of indigenous light elements currently exists for the group. Measurement of the abundances and isotopic composition of carbon and nitrogen could provide information pertaining to the evolution of the angrite parent body. Bulk‐sample stepped combustion analyses of five angrites and a glass separate from D'Orbigny were combined with earlier data and acid dissolution experiments of carbonates found in D'Orbigny to compile an inventory of indigenous carbon and nitrogen. Indigenous carbon combusted between 700 °C and 1200 °C, with abundances of 10–140 ppm and a mass‐weighted δ¹³C of ?25 to ?20‰ with the exception of D'Orbigny (δ¹³C approximately ?5‰). Nitrogen was released at 850–1200 ºC, 1–20 ppm with a δ¹⁵N ?3‰ to +4‰; again, D'Orbigny (δ¹⁵N approximately +20 to +25‰) was an exception. We interpret these components as largely indigenous and decoupled; the carbon in graphitic or amorphous form, while the nitrogen is present as a dissolved component in the silicates. No relationship with the textural sub‐classification of angrites is apparent. We suggest that the angrite parent body contains a reservoir of reduced carbon and thus may have undergone a change in redox conditions, although the timing and mechanism for this remain unclear.  相似文献   

Seasonal Diet Shifts and Overlap Between Two Sympatric Catfishes in an Estuarine Nursery     

David Valença Dantas  Mario Barletta  Jonas de Assis Almeida Ramos  André Ricardo Araújo Lima  Monica Ferreira da Costa 《Estuaries and Coasts》2013,36(2):237-256

This study describes the seasonal feeding habits of different size classes of Cathorops spixii and Cathorops agassizii along an estuarine ecocline and the food overlap when different size classes occur together. These species were essentially zoobenthivorous, feeding mainly on Polychaeta Nereis sp., Copepoda Pseudodiaptomus acutus, Ostracoda Asterope sp., Gastropoda: Littorinidae, and Bivalvia Mytilus sp. and Anomalocardia brasiliana. However, during their life cycle and between different habitats and seasons, their trophic guild can change to zooplanktivore. The competition for resources was observed among C. spixii and C. agassizii, but was significantly reduced due to the seasonal diference in habitat use by different ontogenetic phases in the main channel of the estuary. The food niche separation was strongly influenced by environmental fluctuations, principally of salinity, resulting from rainfall and river inflow. High abundance of some preys, such as P. acutus (all estuary), Asterope sp. (upper and middle estuary), and Littorinidae (upper and lower estuary), could influence the significant diet overlap, principally during the rainy season, and call for more detailed studies of the benthic community structure. Moreover, dietary overlap was observed mainly between smaller sizes (intraspecific and/or interspecific) or between corresponding ontogenetic phases (interspecific), suggesting some differentiation in the diet in relation to the size class. Differences in prey type and size between the different ontogenetic phases of these ariids, principally among juveniles and adults, could be related to the size of the mouth, since adults are able to successfully capture larger preys or larger quantities of particular items.  相似文献   

Internal pore measurements on macroperforate planktonic Foraminifera as an alternative morphometric approach     

Monica Constandache  Florence Yerly  Silvia Spezzaferri 《Swiss Journal of Geoscience》2013,106(2):179-186

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Sedimentary provenance in the central Ribeira belt based on laser-ablation ICPMSPb/Pb zircon ages     

Claudia Sayo Valladares  Nuno Machado  Monica Heilbron  Beatriz Paschoal Duarte  Gilles Gauthier 《Gondwana Research》2008,13(4):516-526

²⁰⁷Pb/²⁰⁶Pb ages from 420 zircons from 9 upper amphibolite and granulite facies quartzites of the post-1.8 Ga metasedimentary cover from the Occidental and Oriental terranes from the Neoproterozoic central Ribeira belt, in eastern Brazil, are discussed. Ages from the Occidental terrane show that Proterozoic ages predominate with a modal class at 2.1–2.2 Ga and that Archean ages are less common and lie within the 2.5–3.6 Ga range. A wider dispersion on Proterozoic ages down to 1.1 Ga and youngest Neoproterozoic ages (550–700 Ma) were also observed and could be related to the Brasiliano/PanAfrican metamorphic events. The data show that detrital sediments of the Occidental terrane were derived predominantly from erosion of a 1.8–2.2 Ga Paleoproterozoic terrane with a small proportion of a 2.6–3.6 Ga Archean crust. Ages from the Oriental terrane are greatly dispersed, but show a significant proportion of ages between 1.7 and 2.1 Ga, although the great majority are between 0.5 and 1.6 Ga. Only 3 out of 144 grains yield Archean ages, between 2.5 and 2.9 Ga. Based on the greatest errors observed on the data from the Oriental Terrane (100–300 Ma), and a continuum of obtained ages between 2072 Ma (Paleoproterozoic) and 517 Ma (Cambrian), the more plausible interpretation is that the dispersion of ages results from partial resetting of the U–Pb system by Brasiliano metamorphism in Proterozoic–Archean zircons, although a Mesoproterozoic source could not be discarded.  相似文献   

The Cost(s) of Geospatial Open Data          下载免费PDF全文

Peter A. Johnson  Renee Sieber  Teresa Scassa  Monica Stephens  Pamela Robinson 《Transactions in GIS》2017,21(3):434-445

The provision of open data by governments at all levels has rapidly increased over recent years. Given that one of the dominant motivations for the provision of open data is to generate ‘value’, both economic and civic, there are valid concerns over the costs incurred in this pursuit. Typically, costs of open data are framed as internal to the data providing government. Building on the strong history of GIScience research on data provision via spatial data infrastructures, this article considers both the direct and indirect costs of open data provision, framing four main areas of indirect costs: citizen participation challenges, uneven provision across geography and user types, subsidy of private sector activities, and the creation of inroads for corporate influence on government. These areas of indirect cost lead to the development of critical questions, including constituency, purpose, enablement, protection, and priorities. These questions are posed as a guide to governments that provide open data in addressing the indirect costs of open data.  相似文献   

Back Analysis of the 2014 San Leo Landslide Using Combined Terrestrial Laser Scanning and 3D Distinct Element Modelling     

Margherita Cecilia Spreafico  Mirko Francioni  Federico Cervi  Doug Stead  Gabriele Bitelli  Monica Ghirotti  Valentina Alena Girelli  Claudio Corrado Lucente  Maria Alessandra Tini  Lisa Borgatti 《Rock Mechanics and Rock Engineering》2016,49(6):2235-2251

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Towards an Integrated Model of Interoperability for Spatial Data Infrastructures     

Miguel-Ángel Manso  Monica Wachowicz  Miguel-Ángel Bernabé 《Transactions in GIS》2009,13(1):43-67

Although there is a vast literature available on interoperability models, and their respective interoperability levels, limited research has been carried out on the development of interoperability models for the implementation of Spatial Data Infrastructures. This article demonstrates the important role of metadata elements in the formalisation of interoperability models for the implementation of Spatial Data Infrastructures. It describes an approach for designing an integrated interoperability model based on the definition of a common template that integrates seven interoperability levels. They are: technical, syntactic, semantic, pragmatic, dynamic, conceptual and organisational levels. A non-hierarchical structure is proposed to ensure the relationship among these interoperability levels.  相似文献   

Size matters more than method: Visual quadrats vs photography in measuring human impact on Mediterranean rocky reef communities     

Valeriano Parravicini  Carla Morri  Giada Ciribilli  Monica Montefalcone  Giancarlo Albertelli  Carlo Nike Bianchi 《Estuarine, Coastal and Shelf Science》2009,81(3):359-367

The performances of two commonly used non-destructive sampling procedures for rocky benthic assemblages (i.e. photography and visually assessed quadrats) were compared. A damaging human activity, date mussel (Lithophaga lithophaga) harvesting (DMH), was chosen. Directly impacted sites were compared with reference conditions (controls). Both visual quadrats and photography were equally able to detect differences between impacted situations and controls. However, visual quadrats showed high variability among replicates and estimated higher species richness for controls, while photography did so for impacts. Pooling photos in a ‘sum photo quadrat’ showed that differences between the two methods are due to sampling unit size rather than sampling procedure itself. As a small sampling unit is unavoidable with photography, visual quadrats should be preferred in investigating shallow rocky reefs for their larger size; however, longer working time underwater with quadrats does not allow for numerous replicates. Pooling many photos to reach sampling sizes comparable with those of quadrats may be a valid alternative to reconcile image resolution and areal coverage.  相似文献