Miracle-dz/UniFAR-FTUs huggingface dataset:
The influence of the Indian Ocean dipole mode on precipitation over the Seychelles

Correlation and composite analysis are applied to study the atmospheric–oceanic mechanisms related to precipitation on the largest island of the Seychelles archipelago, Mahé, in the equatorial western Indian Ocean (EWIO). Significant relationships are found to exist between precipitation and a reversal in zonal wind in the equatorial Indian Ocean (IO), cooler sea surface temperatures (SSTs) in the eastern and southern IO and convergence over Eastern Africa. The observed SST and zonal wind anomalies affecting rainfall in the EWIO are also characteristics of the dipole mode, an Indian Ocean event of internal variability measured by the dipole mode index (DMI). The September–October–November DMI is significantly correlated to December–January–February precipitation in the EWIO, explaining up to 20% of the variance. The analysis suggests an additional influence on variability of rainfall over the EWIO by the sea surface temperatures of the southwest Indian Ocean. Copyright © 2006 Royal Meteorological Society.
Undrained anisotropy of K0-consolidated silt

Direct measurements of the initial shear strength and yielding anisotropy of a dense, K0-consolidated silt are described and interpreted within a bounding-surface framework. The experiments were performed using the Imperial College large hollow cylinder apparatus, in which samples were sheared undrained with a range of orientations, α, of the major principal stress, σ1, following initial K0 consolidation. The interpretation is aided by data from oedometer and triaxial stress path tests. Strongly anisotropic stiffness, yielding, undrained strength, and mobilized angle of shearing resistance, ϕ', characteristics are revealed. The effects of drained and undrained stress changes applied to the samples after K0 consolidation are also described.Key words: anisotropy, hollow cylinder, K0 consolidation, silt, bounding surface.
The Atlantic Subtropical Front/Current Systems of Azores and St. Helena

Abstract A large-scale climatic ocean circulation model was used to study the Atlantic Ocean circulation. This inverse model is an extension of the β-spiral formulation presented in papers by Stommel and Schott with a more complete version of the vorticity equation, including relative vorticity in addition to planetary vorticity. Also, a more complete database for hydrological measurements in the Atlantic Ocean was used, including not only the National Oceanographic Data Center database but also World Ocean Circulation Experiment data and cruises near the Azores, Angola, and Guinea-Bissau. A detailed analysis of the Northern Hemisphere Azores Current and Front shows that this new database and the model results were able to capture all major features reported previously. In the Southern Hemisphere, the authors have identified fully and described the subtropical front that is the counterpart to the Azores Current, which they call the St. Helena Current and Front. Both current systems of both hemispheres hav.
Distribution of Fe, Mg, and Mn between Garnet and Biotite in Natural Mineral Assemblages

The distribution coefficient, $$K_{D} \equiv (Mg/Fe)_{garnet}/(Mg/Fe)_{biotite}$$, has been calculated for seventy garnet-biotite pairs from samples of known mineral assemblage and from a range of metamorphic grade. This distribution coefficient depends upon the metamorphic grade, but it is also dependent upon the Mn content of garnet and upon the detailed mineral assemblage. For a single assemblage from a given metamorphic grade the distribution coefficient is reduced by about 0.007 per 1 atom per cent of $$(Mn/Mn + Mg + Fe)_{garnet}$$. Values of $$K_{D}$$ for isogradic assemblages differ by about 0.045. The distribution coefficient for different metamorphic grades is compared by projection to an arbitrary zero value of $$(Mn/Mn + Mg + Fe)_{garnet}$$. $$K_{D}$$ for garnet-zone rocks is about 0.2, for staurolite-zone rocks about 0.215, for kyanite-zone rocks about 0.23, and for sillimanite-K-feldspar-zone rocks about 0.3-0.37.
Extratropical waves transport boreal wildfire emissions and drive regional air quality dynamics

[1] A synthesis of data and analyses identified eight separate wildfire events (five in boreal Canada and three in the western United States) that impacted the Pittsburgh Supersite, as well as Toronto, during June and July 2002. These data also revealed a larger structure in the nature of pollution episodes in Pittsburgh characterized by alternating periods of stagnation and cleansing. Stagnation resulted in significant and sustained increases in pollutant concentrations that were eventually flushed by clean air transported from Canada. Stagnation events were further characterized by decreases in wind speed, increases in ambient temperature, and enhanced atmospheric processing. Reverse trends were observed during the “clean” periods. Wildfire emissions consistently arrived immediately prior to the stagnation events and tended to be trapped and recirculated by the associated surface high pressure system, prolonging their impact. These receptor site dynamics were correlated to the structure and propagation of transient extratropical synoptic-scale waves, which were characterized by eastward propagating transcontinental trough-ridge-trough configurations. Temporal patterns observed in the Pittsburgh data (a repeating sequence of long-range transport followed by stagnation and then flushing) were in phase with alternating synoptic structures of the propagating waves. Northwesterly subsiding flow between the ridge and trough transported wildfire emissions from the injection height above the fires down into the Pittsburgh and Toronto air sheds. As the wave propagated, the surface high associated with the upper-level ridge passed Pittsburgh, initiating a stagnation event. The cold front associated with the approaching trough flushed the stagnant air but reset the sequence of events as emissions from new wildfires were again transported behind the front. The sequence consistently repeated throughout the study period with a frequency directly correlated to the frequency of extratropical wave formation. Stagnation severity was related to the speed and maturity of the synoptic disturbances while wildfire impact severity corresponded to fire size.
Activation of chlorine in sulfate aerosol as inferred from aircraft observations

The abundance of reactive chlorine in the lower stratosphere is observed to increase sharply with exposure to temperatures below about 195 K, a temperature which is near the nitric acid trihydrate (NAT) equilibrium condensation point. Measurements from the NASA ER-2 aircraft and a model of chemistry along back trajectories are used to examine the mechanism for this apparent temperature threshold in chlorine activation. The flight of July 28, 1994, from the Airborne Southern Hemisphere Ozone Experiment/Measurement s for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA) campaign in the southern hemisphere is studied because it provides measurements in an ongoing activation episode. Isentropic back trajectories from the aircraft sampling points indicate that the sampled air was cooling at the rate of 20 to 30 K d−1 to temperatures below the NAT condensation point and had not been below the NAT condensation point prior to that for at least 10 days. Hence the observed amount of active chlorine should be kinetically limited by the recent parcel temperatures. The measurements show enhanced ClO and decreased HCl at temperatures below 195 K even in the absence of significant polar stratospheric cloud particle surface area. The model of chemistry along back trajectories, constrained by the ER-2 chemical and microphysical measurements, indicates that an initial inorganic chlorine (Cly) partitioning of approximately half HCl and half C1ONO2 is consistent with the observations. At this initial Cly, partitioning, the model using heterogeneous reactions on liquid sulfate and ternary solutions with the most recent sticking coefficient evaluations closely reproduces the latitude gradient and temperature threshold of chlorine activation observed in the data. The sudden increase in activation in the model is a result of the steep exponential temperature dependence of the sticking coefficient for HCl+ ClONO2 on liquid aqueous solutions.
Comparison of the short period rigid earth nutation series.

We present a comparison of the diurnal and subdiurnal nutations of the three last theories of rigid Earth nutation: SMART97, RDAN97 and REN 2000. For a better interpretation of the observations, we characterize their contribution to the polar motion and we estimate the nonrigid effects.
Optical observations of thermospheric dynamics at Arecibo

Observations of thermospheric neutral winds have been made at Arecibo, Puerto Rico, by using a Fabry-Perot interferometer to measure the Doppler shift of the nighttime O(¹D) 630-nm emission. We have developed a scheme of making observations at eight equally-spaced azimuth positions with a constant zenith angle. This technique allows us to determine the mean neutral wind velocities in the meridional and zonal directions, as well as any horizontal gradients in the wind field. It also provides a good means of simultaneously monitoring any spatial variations in neutral temperature and the intensity of the O(¹D) emission. In general, the highest equatorward wind velocity is observed at about 2100 LST. The meridional wind velocity usually lessens as midnight approaches and sometimes, but by no means always, reverses after midnight. The magnitude of the equatorward velocity is greater in summer than in winter months. For winter and spring months, the zonal wind blows eastward throughout the night, with the velocity tending to decrease in a fairly regular fashion from about 125 m s−1 at 2100 LST towards zero by 0400 LST. In summer the pattern is similar, but the eastward flow usually reverses earlier, and a westward velocity of some 50 m s−1 may be attained by 0400 LST. Significant horizontal wind gradients are often observed in the meridional direction, but not in the zonal direction. Near midnight especially, during both the equinox and summer months, the equatorward wind is often greater to the north of Arecibo than to the south. We interpret this as being an effect of the passage of the midnight equatorial pressure maximum to the south of the station. Measurements of neutral temperature with the interferometer do indeed show that, between 0100–0200 LST, the neutral temperature to the south of Arecibo is enhanced by some 40°K over that to the north.
An Integrated Model for Flow and Transport in Surface Water, Groundwater, and Overland Regimes

Abstract This paper presents the mathematical formulation of an integrated surface-subsurface-overland model for flow and transport of thermal energy and salinity. The model contains three major components: a 3D surface water module, a 2D overland module, and a 3D subsurface module. The surface water module simulates flow and transport in the main channel of rivers/estuaries based on the 3D Navier-Stokes equations with or without hydrostatic assumptions. The moving free surface is explicitly handled by solving the kinematic boundary condition equation and a moving grid method with a node-repositioning algorithm is used to track the deformation of the water surface. The surface water transport module solves the energy equation for spatial-temporal distributions of temperature and the mass transport equations for the salinity field. The numerical solution is obtained using the finite element method or the mixed Lagrangian-Eulerian (particle tracking) and finite element method. The overland module solves the 2D simplified diffusive wave equations, and the transport equations for temperature and salinity using the finite element method. The groundwater module adopts the modified Richard's equation, the Darcy's law, and the transport equations to model the flow and transport of temperature and salinity through saturated-unsaturated porous media using the finite element method. The integrated model also enables the dynamic surface-subsurface, surface-overland, and overland-subsurface interactions through the couplings of flows and transports at the interface. The integrated model has been tested and applied to Loxahatchee Estuary for the investigation of floodplain habitat hydroperiod in the Northwest Fork of the river.
Labeled co-occurrence matrix for the detection of built-up areas in high-resolution SAR images

The characterization of urban environments in synthetic aperture radar (SAR) images is becoming increasingly challenging with the increased spatial ground resolutions. In SAR images having a geometrical resolution of few meters (e.g. 3 m), urban scenes are roughly speaking characterized by three main types of backscattering: low intensity, medium intensity, and high intensity, which correspond to different land-cover types. Based on the observations of the behavior of the backscattering, in this paper we propose the labeled co-occurrence matrix (LCM) technique to detect and extract built-up areas. Two textural features, autocorrelation and entropy, are derived from LCM. The image classification is based on a similarity classifier defined in the general Lukasiewicz structure. Experiments have been carried out on TerraSAR-X images acquired on Nanjing (China) and Barcelona (Spain), respectively. The obtained classification accuracies point out the effectiveness of the proposed technique in identifying and detecting built-up areas compared with the traditional grey level co-occurrence matrix (GLCM) texture features.
A Cambrian Tidal Sand Body: The Eriboll Sandstone of Northwest Scotland: An Ancient-Recent Analog

The origin of many mineralogically mature, marine sandstones can be related to paleotidal processes. The Cambrian Eriboll Sandstone of northwest Scotland is divisible into a prominently cross-stratified Lower Member and an Upper Pike Rock Member containing abundant Scolithus ichnofossils. The Lower Member consists of medium-grained, well-sorted, mature quartzarenite and subarkose. Sedimentary structures in this member include planar, herringbone cross-stratification, reactivation surfaces, interference ripples, and both current ripples and micro-cross-laminae superimposed at 90° on slip faces of cross-strata. The frequency distribution of set thicknesses are multimodal, whereas distributions of dip angles of cross-strata are bimodal. Cross-strata azimuth orientations are bimodal and multimodal. The Pipe Rock Member is massive-bedded with burrows of Scolithus and Monocraterion, the latter resembling "escape structures. " Sedimentary structures in the Eriboll Sandstone are comparable bodies. Reactivation surfaces and bimodal distributions of both cross-strata set thickness and dip angles suggest a paleotidal flow mechanism characterized by time-velocity asymmetry. Escape structures of burrows combined with overlying intertidal and supratidal carbonate rocks also indicate a tidal depositional environment for the Eriboll Sandstone. The tidal sand body environment is characterized by intensive reworking, and by equilibrium sand transport patterns through alternate flood-dominated and ebb-dominated zones. Mineralogical and textural maturity is achieved by sediment transport over long distances combined with weathering at intermediate depositional sites. Other quartzarenites displaying similar structures were likely developed in tide-dominated depositional environments.
Validation of the automatic tracking for facial landmarks in 3D motion captured images

Aim: The aim of this study was to validate the automatic tracking of facial landmarks in 3D image sequences captured using the Di4D system (Dimensional Imaging Ltd., Glasgow, UK). MATERIALS AND METHODS: 32 subjects (16 males; 16 females) range 18-35 years were recruited. 23 facial landmarks were marked on the face of each subject with a 0.5 mm non-permanent ink. The subjects were asked to perform three facial animations from the rest position (maximal smile, lip purse and cheek puff). Each animation was captured by a 3D stereophotogrammetry video system (Di4D). A single operator digitized landmarks on captured 3D models and the manual digitised landmarks were compared with the automatic tracked landmarks. To investigate the accuracy of manual digitisation, the same operator re-digitized 2 subjects (1 male and 1 female). RESULTS & CONCLUSION: The discrepancies in x, y and z coordinates between the manual digitised landmarks and the automatic tracked facial landmarks were within 0.5 mm and the mean distance between the manual digitisation and the automatic tracking of corresponding landmarks using tracking software was within 0.7 mm which reflects the accuracy of the method( p value was very small). The majority of these distances were within 1 mm. The correlation coefficient between the manual and the automatic tracking of facial landmarks was 0.999 in all x, y, and z coordinates. In conclusion, Automatic tracking of facial landmarks with satisfactory accuracy, would facilitate the analysis of the dynamic motion during facial animations.
Part I. Tectonic evolution of the northern Gulf of California, Mexico, deduced from conjugate rifted margins of the Upper Delfin Basin. Part II. Active folding and seismic hazard in central Los Angeles, California

Part I of this thesis addresses the tectonic evolution of the Pacific--North America plate boundary through northwest Mexico and its implications for rifting processes. Offset ignimbrites support 255+/-10 km of opening across the Upper Delfin basin of the northern Gulf of California. Additional deformation from the continental margins supports 296+/-17 km total plate boundary displacement between coastal Sonora and the Main Gulf Escarpment in Baja California, of which at least 276+/-13 km occurred since ~6 Ma. This strain history requires that the plate boundary localized into the the northern Gulf of California during latest Miocene time. Only a narrow width of upper continental crust foundered into the Upper Delfin basin, such that most of the crust between Isla Tiburon and Baja California must be new transitional oceanic crust and possibly lower continental crust contributed by inflow from the rift flanks. Extension of the margins of the Upper and Lower Delfin basins is <40% in most places, though the whole crustal column may have been thinned by a factor of two, further supporting that lower crustal flow has operated here. Opening of the Upper Delfin basin was accompanied by a steady or increased strain rate on its continental margins, contrary to the expected rheology of a narrow continental rift. Reevaluation of a critical deposit of marine rocks on Isla Tiburon indicates that initial marine incursion in the northern Gulf of California also occurred during latest Miocene time. Together, these records suggest that opening of the Upper Delfin basin was an abrupt event, accompanied by a localized zone of intense extension, marine incursion, and a rapid increase in strain rate. Continental rupture in the Upper Delfin basin does not appear to have been a response to crustal weakening by intracontinental extension, but rather may have resulted from a significant increase in strain rate, brought on by a change in boundary forces. Part II of this thesis develops methods to estimate seismic hazard from blind reverse faults by analysis of fault-related folding of Late Quaternary strata, with application to the Elysian Park anticline of Los Angeles, California
Late Quaternary tephrostratigraphy, Ahklun Mountains, SW Alaska

Radiocarbon‐dated sediment cores from six lakes in the Ahklun Mountains, south‐western Alaska, were used to interpolate the ages of late Quaternary tephra beds ranging in age from 25.4 to 0.4 ka. The lakes are located downwind of the Aleutian Arc and Alaska Peninsula volcanoes in the northern Bristol Bay area between 159° and 161°W at around 60°N. Sedimentation‐rate age models for each lake were based on a published spline‐fit procedure that uses Monte Carlo simulation to determine age model uncertainty. In all, 62 14C ages were used to construct the six age models, including 23 ages presented here for the first time. The age model from Lone Spruce Pond is based on 18 ages, and is currently the best‐resolved Holocene age model available from the region, with an average 2σ age uncertainty of about ± 109 years over the past 14.5 ka. The sedimentary sequence from Lone Spruce Pond contains seven tephra beds, more than previously found in any other lake in the area. Of the 26 radiocarbon‐dated tephra beds at the six lakes and from a soil pit, seven are correlated between two or more sites based on their ages. The major‐element geochemistry of glass shards from most of these tephra beds supports the age‐based correlations. The remaining tephra beds appear to be present at only one site based on their unique geochemistry or age. The 5.8 ka tephra is similar to the widespread Aniakchak tephra [3.7 ± 0.2 (1σ) ka], but can be distinguished conclusively based on its trace‐element geochemistry. The 3.1 and 0.4 ka tephras have glass major‐ and trace‐element geochemical compositions indistinguishable from prominent Aniakchak tephra, and might represent redeposited beds. Only two tephra beds are found in all lakes: the Aniakchak tephra (3.7 ± 0.2 ka) and Tephra B (6.1 ± 0.3 ka). The tephra beds can be used as chronostratigraphic markers for other sedimentary sequences in the region, including cores from Cascade and Sunday lakes, which were previously undated and were analyzed in this study to correlate with the new regional tephrostratigraphy. Copyright © 2012 John Wiley & Sons, Ltd.
Survey of Potential Radio Frequency Interference Sources.

Abstract : This report is a survey of the potential Radio Frequency Interference (RFI) sources that are currently affecting the analysis of data from the SEASAT Scanning Multichannel Microwave Radiometer (SMMR) and those sources that could affect the design of the Large Antenna Multichannel Microwave Radiometer (LAMMR) for the National Oceanic Satellite System (NOSS). The SEASAT SMMR survey is limited to the 6.5 to 6.7 GHz channel and to emitters on the West Coast of the United States and Canada where RFI has been encountered. The NOSS LAMMR survey covers all of the potential frequencies of interest; 3.0 to 7.6 GHz, 10.5 to 11.0 GHz, 13.4 to 14.0 GHz, 14.5 to 14.7 GHz, 17.0 to 18.8 GHz, 20.8 to 22.4 GHz, 34.0 to 35.5 GHz, 36.0 to 37.0 Ghz, 76.0 to 77.0 GHz, and 88.0 to 94.0 GHz. Also included are excerpts from the current international frequency allocation tables and excerpts from the U.S. position which was presented at the 1979 World Administration Radio Conference (WARC). (Author)
Relationship between wind speed and gas exchange over the ocean

Relationships between wind speed and gas transfer, combined with knowledge of the partial pressure difference of CO2 across the air-sea interface are frequently used to determine the CO2 flux between the ocean and the atmosphere. Little attention has been paid to the influence of variability in wind speed on the calculated gas transfer velocities and the possibility of chemical enhancement of CO2 exchange at low wind speeds over the ocean. The effect of these parameters is illustrated using a quadratic dependence of gas exchange on wind speed which is fit through gas transfer velocities over the ocean determined by the natural-14C disequilibrium and the bomb-14C inventory methods. Some of the variability between different data sets can be accounted for by the suggested mechanisms, but much of the variation appears due to other causes. Possible causes for the large difference between two frequently used relationships between gas transfer and wind speed are discussed. To determine fluxes of gases other than CO2 across the air-water interface, the relevant expressions for gas transfer, and the temperature and salinity dependence of the Schmidt number and solubility of several gases of environmental interest are included in an appendix.