Landslide susceptibility of volcanic landforms in the Río El Estado watershed,Pico de Orizaba volcano,Mexico     

Gabriel Legorreta Paulín  Marcus I. Bursik  José Juan Zamorano Orózco  José Ernesto Figueroa García 《Natural Hazards》2015,77(2):559-574

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Caribbean hurricanes: interannual variability and prediction     

Mark R. Jury  Ernesto Rodr��guez 《Theoretical and Applied Climatology》2011,106(1-2):105-115

Climatic conditions that affect the interannual variability of Caribbean hurricanes are studied. Composite meteorological and oceanographic reanalysis fields are constructed for active and inactive seasons since 1979, and differences are calculated for spring and summer periods to provide guidance in statistical analysis. Predictors are extracted for areas exhibiting high contrast between active and inactive seasons, and intercomparisons are made. Zonal winds north of Venezuela exhibit westerly anomalies prior to active years, so coastal upwelling and the north Brazil current are diminished. Rainfall increases in the Orinoco River basin, creating a fresh warm plume north of Trinidad. The predictor time series are regressed onto an index of Caribbean hurricanes, and multivariate algorithms are formulated. It is found that atmospheric kinematic and convective predictors explain only ??20% of hurricane variance at 3?C5-month lead time. Subsurface ocean predictors offer higher levels of explained hurricane variance (42%) at 3?C5-month lead time, using 1?C200-m-depth-averaged temperatures in the east Pacific and southern Caribbean. We place the statistical results in a conceptual framework to better understand climatic processes anticipating Caribbean hurricanes.  相似文献   

Estimating net radiation at surface using artificial neural networks: a new approach     

Antonio Geraldo Ferreira  Emilio Soria-Olivas  Antonio Jos�� Serrano L��pez  Ernesto Lopez-Baeza 《Theoretical and Applied Climatology》2011,106(1-2):263-279

This study describes the results of artificial neural network (ANN) models to estimate net radiation (R _n), at surface. Three ANN models were developed based on meteorological data such as wind velocity and direction, surface and air temperature, relative humidity, and soil moisture and temperature. A comparison has been made between the R _n estimates provided by the neural models and two linear models (LM) that need solar incoming shortwave radiation measurements as input parameter. Both ANN and LM results were tested against in situ measured R _n. For the LM ones, the estimations showed a root mean square error (RMSE) between 34.10 and 39.48?W?m^?2 and correlation coefficient (R ²) between 0.96 and 0.97 considering both the developing and the testing phases of calculations. The estimates obtained by the ANN models showed RMSEs between 6.54 and 48.75?W?m^?2 and R ² between 0.92 and 0.98 considering both the training and the testing phases. The ANN estimates are shown to be similar or even better, in some cases, than those given by the LMs. According to the authors?? knowledge, the use of ANNs to estimate R _n has not been discussed earlier, and based on the results obtained, it represents a formidable potential tool for R _n prediction using commonly measured meteorological parameters.  相似文献   

Salinity and Chlorophyll a as Performance Measures to Rehabilitate a Mangrove-Dominated Deltaic Coastal Region: the Ci��naga Grande de Santa Marta�CPajarales Lagoon Complex, Colombia     

Victor H. Rivera-Monroy  Robert R. Twilley  J. Ernesto Mancera-Pineda  Christopher J. Madden  Ariel Alcantara-Eguren  E. Barry Moser  Bror F. Jonsson  Edward Casta?eda-Moya  Oscar Casas-Monroy  Paola Reyes-Forero  Jorge Restrepo 《Estuaries and Coasts》2011,34(1):1-19

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Equilibrium Points and Central Configurations for the Lennard-Jones 2- and 3-Body Problems   总被引：1，自引：1，他引：0  

Montserrat Corbera  Jaume Llibre  Ernesto Pérez-Chavela 《Celestial Mechanics and Dynamical Astronomy》2004,89(3):235-266

In this paper we study the relative equilibria and their stability for a system of three point particles moving under the action of a Lennard-Jones potential. A central configuration is a special position of the particles where the position and acceleration vectors of each particle are proportional, and the constant of proportionality is the same for all particles. Since the Lennard-Jones potential depends only on the mutual distances among the particles, it is invariant under rotations. In a rotating frame the orbits coming from central configurations become equilibrium points, the relative equilibria. Due to the form of the potential, the relative equilibria depend on the size of the system, that is, depend strongly of the momentum of inertia I. In this work we characterize the relative equilibria, we find the bifurcation values of I for which the number of relative equilibria is changing, we also analyze the stability of the relative equilibria. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Oil-spill fishery impact assessment model: Application to selected Georges Bank fish species     

Malcolm L. Spaulding  Saul B. Saila  Ernesto Lorda  Henry Walker  Eric Anderson  J.Craig Swanson 《Estuarine, Coastal and Shelf Science》1983,16(5):511-541

An oil-spill fishery impact assessment model composed of an oil-spill fates model, a shelf hydrodynamics model, an ichthyoplankton transport and fate model, and a fishery population model originally developed by Reed & Spaulding, has been improved and applied to the Georges Bank-Gulf of Maine region to assess the probable impact of oil spills on several key fisheries. The model addresses direct impacts of oil on the commercial fishery through hydrocarbon-induced egg and larval mortality. This early life stage hydrocarbon-induced mortality is estimated by assuming a toxicity threshold approach and by mapping the spatial/temporal interaction between the subsurface oil concentrations caused by the spill and the developing eggs and larvae. Model output is given in terms of differential catch, with a comparison made of hydrocarbon-impacted fisheries.Simulations of tanker and blowout spills at two separate locations for each season of the year in the Outer Continental Shelf lease areas have been completed for Atlantic herring, haddock, and Atlantic cod. Results to date suggest a complex interaction among spill location and timing, the spatial and temporal spawning distribution of the species, and the hydrodynamics of the area. The largest impacts occur for spring and winter spills.  相似文献   

Dark Matter: A Result of nonadditive gravitational forces     

Jesús Arturo Robles-Gutiérrez  Ernesto Lacomba Zamora  Jesús Martiniano Arturo Robles-Domínguez  Cinna Lomnitz  María Eugenia Robles-Gutiérrez 《Geofísica Internacional》2013,52(2):153-157

Experimental data in fluids suggest that nonadditive electromagnetic forces between 3 or more molecules account for the existence of critical points, triple states and phase transitions (Robles-Domínguez et al., 2007; Robles-Gutiérrez et al., 2010). Similar nonadditive forces between 3 or more molecules in the gravitational field incorporated into Newton’s universal gravitational law may also explain the existence of dark matter.  相似文献   

Vestan lithologies mapped by the visual and infrared spectrometer on Dawn     

Eleonora Ammannito  M. Cristina De Sanctis  Fabrizio Capaccioni  M. Teresa Capria  F. Carraro  Jean‐Philippe Combe  Sergio Fonte  Alessandro Frigeri  Steven P. Joy  Andrea Longobardo  Gianfranco Magni  Simone Marchi  Thomas B. McCord  Lucy A. McFadden  Harry Y. McSween  Ernesto Palomba  Carle M. Pieters  Carol A. Polanskey  Carol A. Raymond  Jessica M. Sunshine  Federico Tosi  Francesca Zambon  Christopher T. Russell 《Meteoritics & planetary science》2013,48(11):2185-2198

We present global lithological maps of the Vestan surface based on Dawn mission's Visible InfraRed (VIR) Spectrometer acquisitions with a spatial sampling of 200 m. The maps confirm the results obtained with the data set acquired by VIR with a spatial sampling of 700 m, that the reflectance spectra of Vesta's surface are dominated by pyroxene absorptions that can be interpreted within the context of the distribution of howardites, eucrites, and diogenites (HEDs). The maps also partially agree with the ground and Hubble Space Telescope observations: they confirm the background surface being an assemblage of howardite or polymict eucrite, as well as the location of a diogenitic‐rich spot; however, there is no evidence of extended olivine‐rich regions in the equatorial latitudes. Diogenite is revealed on the Rheasilvia basin floor, indicating that material of the lower crust/mantle was exposed. VIR also detected diogenites along the scarp of Matronalia Rupes, and the rims of Severina and a nearby, unnamed crater, and as ejecta of Antonia crater. The diogenite distribution is fully consistent with petrological constraints; although the mapped distribution does not provide unambiguous constraints, it favors the hypothesis of a magma ocean.  相似文献   

The 2010 European Venus Explorer (EVE) mission proposal     

Colin Frank Wilson  Eric Chassefière  Emmanuel Hinglais  Kevin H. Baines  Tibor S. Balint  Jean-Jacques Berthelier  Jacques Blamont  Georges Durry  Csaba S. Ferencz  Robert E. Grimm  Takeshi Imamura  Jean-Luc Josset  Fran?ois Leblanc  Sebastien Lebonnois  Johannes J. Leitner  Sanjay S. Limaye  Bernard Marty  Ernesto Palomba  Sergei V. Pogrebenko  Scot C. R. Rafkin  Dean L. Talboys  Rainer Wieler  Liudmila V. Zasova  Cyrill Szopa 《Experimental Astronomy》2012,33(2-3):305-335

The European Venus Explorer (EVE) mission described in this paper was proposed in December 2010 to ESA as an ‘M-class’ mission under the Cosmic Vision programme. It consists of a single balloon platform floating in the middle of the main convective cloud layer of Venus at an altitude of 55?km, where temperatures and pressures are benign (～25°C and ～0.5 bar). The balloon float lifetime would be at least 10 Earth days, long enough to guarantee at least one full circumnavigation of the planet. This offers an ideal platform for the two main science goals of the mission: study of the current climate through detailed characterization of cloud-level atmosphere, and investigation of the formation and evolution of Venus, through careful measurement of noble gas isotopic abundances. These investigations would provide key data for comparative planetology of terrestrial planets in our solar system and beyond.  相似文献   

Improved initial ensemble generation coupled with ensemble square root filters and inflation to estimate uncertainty     

Laura Dovera  Ernesto Della Rossa 《Computational Geosciences》2012,16(2):437-453

The performance of the Ensemble Kalman Filter method (EnKF) depends on the sample size compared to the dimension of the parameters space. In real applications insufficient sampling may result in spurious correlations which reduce the accuracy of the filter with a strong underestimation of the uncertainty. Covariance localization and inflation are common solutions to these problems. The Ensemble Square Root Filters (ESRF) is also better to estimate uncertainty with respect to the EnKF. In this work we propose a method that limits the consequences of sampling errors by means of a convenient generation of the initial ensemble. This regeneration is based on a Stationary Orthogonal-Base Representation (SOBR) obtained via a singular value decomposition of a stationary covariance matrix estimated from the ensemble. The technique is tested on a 2D single phase reservoir and compared with the other common techniques. The evaluation is based on a reference solution obtained with a very large ensemble (one million members) which remove the spurious correlations. The example gives evidence that the SOBR technique is a valid alternative to reduce the effect of sampling error. In addition, when the SOBR method is applied in combination with the ESRF and inflation, it gives the best performance in terms of uncertainty estimation and oil production forecast.  相似文献