Miracle-dz/UniFAR-FTUs huggingface dataset:
Linear Stability Models of Shelfbreak Fronts

Abstract The stability of inviscid frontally trapped waves along a shelfbreak is examined to determine whether frontal instabilities may contribute to the alongfront variability frequently observed. Three different basic states with increasingly complex stratification are treated. In each case, the shelfbreak occurs where a constant depth shelf meets a slope region with linearly increasing depth. The first basic state consists of an unstratified flow with a velocity discontinuity located at the shelfbreak. The resulting shear waves are stable for the velocity shear and topography typical of the Middle Atlantic Bight. Next, a two-layer, geostrophically balanced front located at the shelfbreak is considered. This is similar to the configuration of Flagg and Beardsley, but with an unbounded bottom topography offshore beyond the frontal region. For parameters typical of the Middle Atlantic Bight in winter, the most unstable wave is surface-trapped with a typical e-olding growth time scale of 9.5 days. The mos.
Absolute Hydraulic Conductivity Estimates from Aquifer Pumping and Tracer Tests in a Stratified Aquifer

Independent estimates of absolute hydraulic conductivity were obtained by a “standard” aquifer pumping test and a forced‐gradient tracer test in a highly heterogeneous aquifer. An aquifer hydraulic test was conducted to evaluate the average hydraulic conductivity (K), and to establish steady‐state flow for the tracer test. An average K of 48 m/day was interpreted from the drawdown data in a fully screened well. Type‐curve matching and simulation with MODFLOW of the hydraulic response in partially screened wells indicates K of 10 to 15 m/day for the upper section and 71 to 73 m/day for the deeper section. Iodide and fluorescent dye tracers were injected at low rates in wells located approximately 8 m upgradient of the production well. Tracer breakthrough was monitored in the production well and at ten depth intervals within the fully screened monitoring well. Interpretation of tracer response in the production well reveals tracer transport is limited to a 3.9 m thick section of the 20 m thick aquifer, with a hydraulic conductivity of 248 m/day. However, the depth distribution of these permeable strata cannot be determined from the production well tracer response. When sampled at 1.5 m depth intervals in the monitoring well, breakthrough was observed in only three intervals along the entire 18.2 m screened well. K estimates from tracer travel time within discrete high‐permeability strata range from 31 to 317 m/day. Inclusion of permeameter K estimates for the lower permeability aquifer sands (4–10 m/day) result in a range in relative K of 0.01 to 1.0. This field site has the highest absolute K estimate for a discrete stratum and the widest range in relative hydraulic conductivity amongst research field sites with K estimates for discrete strata. Within such a highly stratified aquifer, the use of an average K from an aquifer pumping test to predict solute transport results in great underestimation of transport distances for a given time period.
CFD Simulation of Gas Pollutant Motion and Dispersion Problem in Wind Tunnel with Respect to Froude Number

Low speed wind tunnels have been used for simulation of wide range of physical problems. One of many possible applications is a simulation of gas pollutant motion and dispersion considering different density of each one. Source term can be defined as a point source, line source or volume source. If modeled geometry with the source is downscaled geometrically and pollutant release is limited (considering all other atmospheric conditions consistent), the plume of pollutant can change its way of motion and dispersion (comparing with the reality). These changes include not only a shape of the plume but also an ability of plume to climb or descent in the atmosphere. Especially plume vertical motions are of the highest importance for the plume motion and dispersion in the real atmosphere. The main point of this article is to prove that downscaled physical experiments based on gas pollutant’s motion and dispersion could not be always the best approach for making gas dispersion studies in the field of emergency p.
Phenology-Based Assessment of Perennial Energy Crops in North American Tallgrass Prairie

Biomass is the largest source of renewable energy in the United States, and corn ethanol currently constitutes the vast majority of the country's biofuel. Extended plantation of annual crops for biofuel production, however, has raised concerns about long-term environmental, ecological, and socioeconomic consequences. Switchgrass (Panicum virgatum L.), along with other warm-season grasses, is native to the precolonial tallgrass prairie in North America and is identified as an alternative energy crop for cellulosic feedstocks. This article describes a phenology-based geospatial approach to mapping the geographic distribution of this perennial energy crop in the tallgrass prairie. Time series of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery (500-m resolution, eight-day interval) in 2007 were processed to extract five phenology metrics: end of season, season length, peak season, summer dry-down, and cumulative growth. A multitier decision tree was developed to map major crops, especially native prairie grasses in the region. The geographic context of the 20 million ha of perennial native grasses extracted in this study could be combined with economic and environmental considerations in a geographic information system to assist decision making for energy crop development in the prairie region.
Comparison between measurements and model simulations of solar radiation at a high altitude site: Case studies for the Izana BSRN station

In this work we have carried out a comparative study of shortwave downward radiation (SDR) measurements and simulations obtained with the radiative transfer model (RTM) LibRadtran in order to be used as a model quality control at Izana BSRN (Baseline Surface Radiation Network). We selected cases corresponding to the most common atmospheric conditions at the Izana station (IZA), we analyzed: clear-sky and African dust intrusions. The input parameters for the model, such as a total ozone column, surface albedo, water vapour column and aerosols parameters, were measured at IZA. The results of the two clear-sky case studies (16 May and 26 October 2010) analyzed here show an underestimation of the simulations for the SDR global and direct for solar zenith angles (SZA) lower than 70°. The maximum relative differences for SDR global, direct and diffuse are 6%, 2% and 6%, respectively. For dust intrusion case studies (22 July 2009 and 10 July 2010) and for SZA lower than 70°, the simulations of the direct normal .
Real-time monitoring of vegetation biomass with NOAA-AVHRR in Etosha National Park, Namibia, for fire risk assessment

Estimates of biomass production are important in a wildlife reserve such as Etosha National Park, Namibia, for assessment of fire risk and subsequent selection of sites for controlled burning. We present methodology for using locally acquired NOAA-AVHRR images to make estimates of biomass in near-to-realtime. To this end, techniques for rapid measurement of the biomass of herbaceous and woody vegetation were developed using a rising disc pasture meter and individual plant dimensions. A field sampling methodology is presented to make biomass estimates which were compatible with the scale of AVHRR spatial resolution and sufficiently close to the time of satellite overpasses to enable correlation with the NDVI from single images. Initial results show high correlations of biomass with NDVI for individual vegetation cover classes, which appear to be temporally stable. There seem to be different regression equations for the different savanna vegetation types although more field observations are needed to confirm this. The results were exploited to illustrate the potential application of this work for fire management. The combination of rapid field methods and real time image acquisition developed in this work provides a sound basis for biomass monitoring at local level.
National Seismic Hazard Model for New Zealand: 2010 Update

A team of earthquake geologists, seismologists, and engineering seis- mologists has collectively produced an update of the national probabilistic seismic hazard (PSH) model for New Zealand (National Seismic Hazard Model, or NSHM). The new NSHM supersedes the earlier NSHM published in 2002 and used as the hazard basis for the New Zealand Loadings Standard and numerous other end-user applica- tions. The new NSHM incorporates a fault source model that has been updated with over 200 new onshore and offshore fault sources and utilizes new New Zealand-based and international scaling relationships for the parameterization of the faults. The dis- tributed seismicity model has also been updated to include post-1997 seismicity data, a new seismicity regionalization, and improved methodology for calculation of the seismicity parameters. Probabilistic seismic hazard maps produced from the new NSHM show a similar pattern of hazard to the earlier model at the national scale, but there are some significant reductions and increases in hazard at the regional scale. The national-scale differences between the new and earlier NSHM appear less than those seen between much earlier national models, indicating that some degree of consis- tency has been achieved in the national-scale pattern of hazard estimates, at least for return periods of 475 years and greater. Online Material: Table of fault source parameters for the 2010 national seismic- hazard model.
Spatial evaluation of a multi‐class sediment transport and deposition model

This paper presents a model for the description of sediment ﬂuxes and deposition processes in a two‐dimensional spatial context using the multiple‐class Hairsine et al. sediment deposition equations. The model describes size‐selective net deposition as a result of simultaneous deposition by settling and non‐selective re‐entrainment of previously deposited sediment. A critical comparison of ﬁeld observations of net erosion and deposition in a watershed with complex topography with this physically based model is presented. The evaluation shows that the deposition model is capable of simulating reasonably both the observed size selectivity and spatial patterns of the deposition process. In this ﬁeld study, the zone where a net deposit of sediment is re‐entrained by overland ﬂow was predicted to be quite limited spatially due to low sediment concentrations and the absence of aggregates in the eroded soil. Copyright © 2004 John Wiley & Sons, Ltd.
On the dynamical basis for the Asian summer monsoon rainfall-El Niño relationship

Abstract The dynamical basis for the Asian summer monsoon rainfall-El Nino linkage is explored through diagnostic calculations with a linear steady-state multilayer primitive equation model. The contrasting monsoon circulation during recent El Nino (1987) and La Nina (1988) years is first simulated using orography and the residually diagnosed heating (from the thermodynamic equation and the uninitialized, but mass-balanced, ECMWF analysts) as forcings, and then analyzed to provide insight into the importance of various regional forcings, such as the El Nino–related heating anomalies over the tropical Indian and Pacific Oceans. The striking simulation of the June–August (1987–1988) near-surface and upper-air tropical circulation anomalies indicates that tropical anomaly dynamics during northern summer is essentially linear even at the 150-mb level. The vertical structure of the residually diagnosed heating anomaly that contributes to this striking simulation differs significantly from the specified canonic.
Grit, Life Satisfaction and Psychological Well-Being Among Women Entrepreneurs

: Most of the studies on women entrepreneurs from psychological perspective focused on the gender stereotypes, motives and the cognitive aspects with related to demographics. But studies from positive psychology perspective are limited and this paper initiated to study interrelation between grit, life-satisfaction and psychological well-being among women entrepreneurs, as these variables were less studied together in the context of women entrepreneurship. The sample size consists of (N= 30) women of age range 30 to 45. All of the participants pursued either graduation or post-graduation. These women are successfully running their business since 7 to 5 years in the city of Hyderabad. Their businesses fall under the category of micro and small-scale enterprises. Data was analyzed using Minitab and findings revealed that there is a significant positive correlation between all the three study variables grit, life satisfaction and psychological well-being.
ARE NEW URBAN FORMS EMERGING? EMPIRICAL TESTS FOR CANADIAN URBAN AREAS

Frequent reference is made in the urban literature to a recent and massive restructuring of the form of contemporary cities. This paper tests five separate but related hypotheses concerning the outcomes of this process and whether they suggest the emergence of new urban forms. The analysis builds on the results reported in an earlier paper in this journal using data on the changing intraurban properties of the 27 largest urban areas in Canada. The empirical results confirm the hypotheses of a continued decentralization of population and employment and of an increasingly diverse social and ethnocultural landscape. They do not, however, support the hypotheses of higher levels of residential segregation by income nor the emergence of an elite inner city (the reverse social status gradient). A wider spatial mismatch between the distribution of jobs and labour is confirmed by journey-to-work data, but primarily for inner city residents. In addition, these data suggest that, despite the rapid suburbanization of employment, a distinct multi-nucleated urban form has not as yet emerged. Les publications dans le domaine de la litterature urbaine font etat frequemment d'une restructuration massive et recente de l'organisation des villes contemporaines. Le present article examine cinq hypotheses differentes quoique reliees—hypotheses quant a l'issue du processus de restructuration et quant a l'emergence possible de nouvelles formes. L'analyse s'appuie sur les resultats rapportes dans un article precedent publie dans cette revue et utilisant des donnees sur les proprietes intra-urbaines en changement dans les 27 agglomerations urbaines les plus importantes du Canada. Les resultats empiriques confirment fes hypotheses d'une decentralisation continue de la population et de l'emploi et d'un paysage social et ethnoculturel de plus en plus divers. Cependant les resultats n'appuientpas I'hypothese d'une plus grande segregation residentielle d'apres le revenu ou encore l'hypothese de l'emergence d'un centre urbain occupe par l'elite (le gradient inverse du statut social). Les donnees du trajet au travail confirment l'existence d'un desequilibre spatial beaucoup plus grand entre la distribution des emplois et celle de la main d'euvre, ceci principalement chez les residents du centre. De plus ces donnees suggerent qu'une forme distincte de nuclei multiple n'est pas encore apparue malgre une decentralisation rapide de l'emploi en banlieue.
Radiative and energetic constraints on the global annual mean atomic oxygen concentration in the mesopause region

We present a new approach to constrain and validate atomic oxygen (O) concentrations in the mesopause region (~ 80 to ~ 100 km). In a prior companion paper [Mlynczak et al., ], we presented O‐atom concentrations in the mesopause region inferred from measurements of day ozone and night hydroxyl emission rates made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument. The approach presented here uses the constraint of global, annual mean energy balance to derive atomic oxygen concentrations, consistent with rates of radiative cooling by carbon dioxide (CO2) and solar heating due to molecular oxygen (O2). The mathematical difference between these cooling and heating rates, on a global annual mean basis, effectively constrains the maximum heating rate for the sum of all other processes. The remaining terms, solar heating due to ozone plus a series of exothermic chemical reactions can be expressed as functions of O. This new approach enables a simple mathematical expression that yields the vertical profile of global annual mean “radiatively constrained” atomic oxygen in the mesopause region. The radiatively constrained atomic oxygen depends only on the CO2 cooling rates, O2 solar heating rates, and standard reaction rate coefficients and enthalpies. Radiative cooling and solar heating rates used in these analyses are derived from measurements made by the SABER instrument on the NASA Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. There is excellent agreement between the SABER radiatively constrained atomic oxygen and that derived from the SABER ozone and OH emission measurements over most of the mesopause region. Radiatively constrained atomic oxygen represents an upper limit on the global average O‐atom concentration in the mesopause region.
SPARROW Modeling of Nitrogen Sources and Transport in Rivers and Streams of California and Adjacent States, U.S.

The SPARROW (SPAtially Referenced Regressions On Watershed attributes) model was used to evaluate the spatial distribution of total nitrogen (TN) sources, loads, watershed yields, and factors affecting transport and decay in the stream network of California and portions of adjacent states for the year 2002. The two major TN sources to local catchments on a mass basis were fertilizers and manure (51.7%) and wastewater discharge (15.9%). Other sources contributed < 12%. Fertilizer use is widespread in the Central Valley region of California, and also important in several other regions because of the diversity of California agriculture. Precipitation, sand content of surficial soils, wetlands, and tile drains were important for TN movement to stream reaches. Median streamflow in the study area is about 0.04 m3/s. Aquatic losses of nitrogen were found to be most important in intermittent and small to medium sized streams (0.2‐14 m3/s), while larger streams showed less loss, and therefore are important for TN transport. Nitrogen loss in reservoirs was found to be insignificant, possibly because most of the larger ones are located upstream of nitrogen sources. The model was used to show loadings, sources, and tributary inputs to several major rivers. The information provided by the SPARROW model is useful for determining both the major sources contributing nitrogen to streams and the specific tributaries that transport the load.
Case Studies of Extreme Climatic Events in the Amazon Basin

Abstract The mechanisms of climate anomalies in the Amazon basin were explored from surface climatological and hydrological series, upper-air, and satellite observations. The paper is focused on the March–April rainy season peak in the northern portion of Amazonia. Case studies for the moderately wet year 1986 (WET), showed a relatively far-southerly location of the Atlantic near-equatorial trough, and embedded intertropical convergence zone (ITCZ); strong ascending motion and vigorous convection over the Amazon basin, contrasting with pronounced subsidence off the west coast of South America,, and weak subtropical westerly jets (STWJ) in both hemispheres. In contrast, the extremely dry El Nino year 1983 (DRY), featured a more northward located ITCZ; subsidence over the Amazon basin; ascending motion and convective rainfall to the west of the Andes; and strong STWJ. In synthesis from these analyses, some major mechanisms of extreme rainfall events in northern Amazonia stand out, but only for the late aust.
Interannual sea surface salinity and temperature changes in the western Pacific warm pool during 1992–2000

[1] Sea surface salinity (SSS) and sea surface temperature (SST) in the western Pacific warm pool (130–180°E; 10°N–10°S) are analyzed for the period 1992–2000 taking advantage of complementary data from the ship of opportunity program and the Tropical Atmosphere-Ocean (TAO)-Triangle Trans-Ocean Buoy Network (TRITON) array of moored buoys. Covariability of these variables with surface wind stress, surface zonal currents, evaporation, precipitation, and barrier layer thickness is also examined. These fields all go through large oscillations related to the El Nino Southern Oscillation (ENSO) cycle, most notably during the record breaking 1997–1998 El Nino and subsequent strong 1998–2000 La Nina. East of about 160°E, during El Nino, precipitation minus evaporation increases in the equatorial band, in conjunction with anomalous increases in westerly winds, eastward surface currents, SST, and decreases in SSS. Opposite tendencies are evident during La Nina. Peak to peak 2°N–2°S averaged variations reached as much as 1.2 m s−1 for zonal currents and 1.5 practical salinity units (psu) for SSS. West of about 160°E, SST cools during El Nino and warms during La Nina, opposite to what occurs further east. To understand these SST tendencies west of 160°E, a proxy indicator for barrier layer formation is developed in terms of changes in the zonal gradient of SSS (∂S/∂x). Zonal SSS gradients have been shown in modeling studies to be related to barrier layer formation via subduction driven by converging zonal currents in the vicinity of the salinity front at the eastern edge of the warm pool. Correlation between changes in ∂S/∂x and changes in SST a few degrees longitude to the west is significantly nonzero, consistent with the idea that increased barrier layer thickness is related to warmer SSTs during periods of westward surface flow associated with La Nina, and vice versa during El Nino. Direct evidence of barrier layer thickness variations in support of this hypothesis is also presented.
A smoothed particle hydrodynamics model for reactive transport and mineral precipitation in porous and fractured porous media

A numerical model based on smoothed particle hydrodynamics (SPH) was used to simulate reactive transport and mineral precipitation in porous and fractured porous media. The stability and numerical accuracy of the SPH‐based model was verified by comparing its results with analytical results and finite element numerical solutions. The numerical stability of the model was also verified by performing simulations with different time steps and different number of particles (different resolutions). The model was used to study the effects of the Damkohler and Peclet numbers and pore‐scale heterogeneity on reactive transport and the character of mineral precipitation and to estimate effective reaction coefficients and mass transfer coefficients. Depending on the combination of Damkohler and Peclet numbers the precipitation may be uniform throughout the porous domain or concentrated mainly at the boundaries where the solute is injected and along preferential flow paths. The effective reaction rate coefficient and mass transfer coefficient exhibited hysteretic behavior during the precipitation process as a result of changing pore geometry and solute distribution. The changes in porosity and fluid fluxes resulting from mineral precipitation were also investigated. It was found that the reduction in the fluid flux increases with increasing Damkohler number for any particular reduction in the porosity. The simulation results show that the SPH, Lagrangian particle method is an effective tool for studying pore‐scale flow and transport. The particle nature of SPH models allows complex physical processes such as diffusion, reaction, and mineral precipitation to be modeled with relative ease.