Miracle-dz/UniFAR-FTUs huggingface dataset:
Constraints on mantle viscosity from relative sea level variations in Hudson Bay

A number of previous analyses have suggested that the relative sea level record in Hudson Bay constrains the viscosity of the lower mantle to be near 1021 Pa s. These conclusions have been based on a limited number of forward calculations which have assumed an isoviscous lower mantle region. We compute Frechet kernels for the RSL data in Hudson Bay to determine the detailed depth-dependent sensitivity of the data to variations in a viscosity profile which is consistent with the past inferences. We find that the RSL data provide a robust constraint on the average viscosity in the top half of the lower mantle only (the average must be near 1021 Pa s). The data are less sensitive to variations in the viscosity below approximately 1800 km depth and in the upper mantle. Forward analyses included herein show that the data admit models whose average viscosity in the deep mantle (below 1800 km depth) and in the upper mantle can differ significantly from the value (near 1021 Pa s) estimated for the top half of the lower mantle. The total variation in the viscosity from the surface to the CMB can exceed an order of magnitude or more and still satisfy the constraint provided by the Hudson Bay RSL data set. The necessity of invoking an isoviscous mantle model in previous studies is thus seen to be a consequence of the limited class of viscosity model solutions employed in those studies.
Classification of pre‐eruption and non‐pre‐eruption epochs at Mount Etna volcano by means of artificial neural networks

We apply artificial neural networks to the classification of pre‐eruption time epochs of Mount Etna volcano on the basis of variables depending on tectonics and on the volcano ‘recharging system’. We consider time‐epochs from 7 to 30 days and train the supervised nets, with the aim of recognizing the time epochs preceding summit eruptions, lateral eruptions and not preceding any eruption. Tested on a number of independent data sets, these patterns are found to be efficient (75 ± 10% success) in recognizing pre‐summit eruption epochs, while distinguishing pre‐lateral from non‐pre‐eruption epochs is impossible. We then apply non‐supervised algorithms to the whole set of data obtaining a confirmation of the findings of supervised nets. This difficulty in recognizing patterns characteristic of pre‐lateral eruption epochs is at odds with all previous work and seems to depend on the small size of the eruptive series, which makes unstable the results of any multivariate analysis.
USING MIST -NETS ON CANOPY WALKWAYS IN MALAYSIA TO STUDY CANOPY A VIF AUNA

The aim of this short-term study was to assess the canopy avifauna by deploying mist-nets on canopy walkways in the tropical rain forest of Malaysia. Twenty-four mist-nets were deployed at height from 5 to 33.3 m on the existing aerial canopy walkways at three study sites; Poring Hot Spring, Sabah; Lambir Hills National Park, Sarawak; and Taman Negara National Park, Peninsular Malaysia. In total, 56 birds were captured representing 39 species and 22 families. Simpson's Diversity Index (Sill) values did not vary significantly between sites. However, there was a difference between the species of birds caught in the canopy mist-nets and those species either seen during the study or commonly caught in conventional mist-nets on the ground. These results suggest that canopy mist-nets deployed on canopy walkways are a useful additional tool in avifauna surveys because they detect species commonly missed by other techniques. In addition, the technique does not require special equipment to assemble, extra cost or time.
A search for ELF/VLF emissions induced by earthquakes as observed in the ionosphere by the DE 2 satellite

Satellite observations of ELF/VLF wave activity by groups from both the Soviet Union and France have indicated the possibility of ELF/VLF radio emissions generated by earthquakes. However, an examination of ELF/VLF wave data from the low-altitude (apogee ∼ 1300 km, perigee ∼300 km, inclination ∼90°) Dynamics Explorer 2 (DE 2) satellite showed no clearly distinguishable ELF/VLF signatures associated with earthquakes. After an initial survey of approximately 5000 DE 2 orbits, ELF and VLF wave data were selected from 63 satellite orbits, called earthquake orbits, in which the ionospheric footprint of the DE 2 crossed the geographic latitude while passing within ±20° geographic longitude of the epicenters of imminent or recent earthquakes of magnitude ≥5.0. ELF/VLF noise measured near the epicenters was analyzed for occurrence rates and average spectra, as well as for peak and mean electric field intensities in three spectrometers covering a frequency range of 4 Hz - 512 kHz in 20 channels. The same analysis was then repeated for 61 carefully matched control orbits when there were no imminent or recent earthquakes within ±20° geographic longitude or within ±10° geographic latitude of the satellite footprint. These control orbits resembled the earthquake orbits with respect to latitude, longitude, local time, and geomagnetic index Kp. Sixty-three percent of the earthquake orbits showed an ELF or VLF emission above 10 µV/m in at least one of the 20 channels when the satellite passed near an epicenter. The same analysis performed on control orbit data yielded a 62% chance of observing similar emissions. Moreover, these results did not change when geomagnetic latitudes, instead of geographic latitudes, were considered. Further analyses failed to indicate any significant differences between the ELF/VLF noise measured on earthquake orbits and control orbits with regard to the general nature of the spectra, the frequency of occurrence of emissions, and peak and mean values of the electric field of the emissions.
Model near‐infrared optical constants of olivine and pyroxene as a function of iron content

The imaginary coefficients of the complex index of refraction of olivine, low-Ca orthopyroxene, and high-Ca clinopyroxene are derived as a function of iron content and wavelength over the spectral region 0.4 to 2.5 μm from reflectance spectra of powders and Hapke radiative transfer theory. Reflectance spectra as a function of composition and grain size are computed and compared. I find that while spectral effects of variations in these parameters are similar, they are distinguishable. Variations in iron content do not explain all the observed spectral variations in the spectra of the samples investigated.
The Role of the Tropical Indian Ocean in Global Climate

Among the most striking decadal climatic trends of the last century are the strengthening of the NAO index and the decreasing summer monsoon rainfall over sub-Saharan West Africa. This thesis focuses on the role of tropical sea surface temperatures (SSTs) driving theses changes. Both of these changes are investigated by conducting experiments with the atmospheric general circulation model ECHAM4.5 - run in stand-alone mode - and the global ocean-atmosphere-sea ice model MPI-OM/ECHAM5. These experiments provide evidence that the Indian Ocean warming in the last decades is of paramount importance in driving the recent observed drying trend over the West Sahel. The model West Sahel dried more when tropical seas were warmer during the past half-century than when they were cooler. When sea surface temperatures were changed in one ocean basin at a time, it was the tropical Indian Ocean that dominated. The warming of the Indian Ocean produces through atmospheric teleconnections mid-tropospheric large-scale subsidence over sub-Saharan West Africa. The Indian and eastern tropical Atlantic Oceans are key ocean areas for driving the two basic rainfall anomaly patterns over sub-Saharan West Africa in summer. This could improve the ability to predict sub-Saharan West African rainfall variability on interannual time-scales. It is found further that the progressive warming of the tropical Indian Ocean is a principal contributor to the strengthening of the North Atlantic Oscillation via the jet stream waveguide.
Establishing the sensitivity of Synthetic Aperture Radar to above-ground biomass in wooded savannas

Radar for biomass estimation has been widely investigated for temperate, boreal and tropical forests, yet tropical savanna woodlands, which generally form noncontinuous cover canopies or sparse woodlands, have been largely neglected in biomass studies. This thesis evaluates the capability of Synthetic Aperture Radar (SAR) for estimating the above-ground biomass of the woody vegetation in a savanna in Belize, Central America. This is achieved by evaluating (i) polarimetric Synthetic Aperture Radar (SAR) backscatter and (ii) single-pass shortwave interferometric SAR (InSAR) as indicators of above-ground biomass. Specifically, the effect on SAR backscatter of woody vegetation structure such as canopy cover, basal area, vegetation height and above-ground biomass is evaluated. Since vegetation height is often correlated to above-ground biomass, the effectiveness of vegetation height retrieval from InSAR is evaluated as an indicator of above-ground biomass. The study area, situated in Belize, is representative of Central American savannas. Radar data used are AIRSAR fully polarimetric Land P-band SAR, and AIRSAR C-band InSAR, Intermap Technologies STAR-3i X-band InSAR, and Shuttle Radar Topography Mission (SRTM) C-band InSAR. The field data comprise accurately georeferenced three-dimensional measurements for 1,133 trees and shrubs and 75 palmetto clumps and thickets in a transect of 800 m x 60 m which spans the main savanna vegetation strata of the study area. An additional 2,464 ground points were observed. Results show that savanna woodlands present a challenge for radar remote sensing methods due to the sparse and heterogeneous nature of savanna woodlands. Longwave SAR backscatter is dominated not only by high biomass areas, but also by areas of leafy palmetto which have low vegetative biomass. Retrieved woodland canopy heights from Xand C-band InSAR are indicative of the general patterns of tree height, although retrieved heights are underestimated. The amount of underestimation is variable across the different canopy conditions. Of these two methods, the shortwave InSAR data give a better indication of the spatial distribution
TRADITIONAL AGROFORESTRY SYSTEMS AS A SAFE HAVEN FOR WOODY PLANT SPECIES: A CASE STUDY FROM A TOPO-CLIMATIC GRADIENT IN SOUTH CENTRAL ETHIOPIA

ABSTRACT The deliberate maintenance of woody species in traditional agroforestry systems could partly compensate the high rate of deforestation in terms of conserving plant diversity. However, this role of traditional agroforestry is little documented. In this study we assessed the diversity of traditional agroforestry based production systems and their woody plant species across four agro-ecological zones (AEZs) near the central Rift Valley in Ethiopia. A total of 120 farms representing households of three wealth categories—poor, medium and rich—were assessed. A large variety of traditional agroforestry systems combinations existed. In total we identified 86 tree/shrub species belonging to 44 families, 71 of which were indigenous and the rest exotics. 95% of households retained trees while transforming natural forests into agricultural landscapes and 70% complemented with planting. There were variations in woody species richness between the AEZs and wealth classes. Similarly, some socio-economic attributes of the farm households such as land holding size, educational background of household head and off-farm activities were found to affect woody species composition in the agroforestry systems.
Nonlocal nonreactive transport in heterogeneous porous media with interregional mass diffusion

We present a Eulerian stochastic analysis for nonreactive transport in a heterogeneous, structured medium. A first‐order mass diffusion model (or mobile and immobile model) is applied to describe interregional mass diffusion between advection and nonadvection (mobile and immobile) regions. Spatial variabilities in the media motivate us to treat the interregional mass diffusion coefficient a and hydraulic conductivity K as spatial random variables. The two random variables are assumed to correlate with each other. The analytical solution for mean concentration is given explicitly in Fourier and Laplace transforms and is numerically inverted to real space via fast Fourier transform. Various factors that affect mass diffusion and transport processes are investigated by plotting spatial moments up to third and mean concentration contours. It is shown from the calculation results that interregional mass diffusion will significantly increase plume dispersion in both longitudinal and transverse directions and make the plume negatively skewed and give the breakthrough curve a long tail. In comparison with the case with a deterministic a, randomness of the parameter will increase the plume dispersion and make the plume more skewed, especially for the case where a is negatively correlated with K.
Soil: Morphology, Genesis, and Classification

Concepts and Definitions of Soil. Terminology and Relationships Between Segments of the Eartha s Crust. ABC System of Horizon Nomenclature. Introduction to Ways of Thinking About and Studying Soil Genesis. Mineral and Organic Matter Transformations. Eluviation and Illuviation and Closely Related Processes (Diffusion, Wicking). Phyto-- and Other Biocycling. Pedoturbation and Soil Structure Formation. Erosion, Alluviation and Other Additions to Soils. Sulfidization and Sulfuricization. Salinization, Solonization, and Solodization. Calcification. Lessivage. Podzolization. Latasolization and Lateritization. Gleization. General Principles and Kinds of Soil Classification Systems. Soil Classification in the Past----Roots and Philosophies. History Leading to the Development of Soil Taxonomy. Pedons and Polypedons and Their Relationship to Mapping Delineations. Soil Taxonomy: Epipedons. Diagnostic Subsurface Horizons. Pans and Plinthite. Proposed Special Diagnostic Characteristics for Highly Man--Influenced Soils. Other Characteristics and Terms Used in Defining Mineral Soils and Classes of Them. Diagnostic Criteria for Organic Soils. General View of Division of Soils into Orders. Entisols. Vertisols. Inceptisols. Aridosols. Mollisols. Spodosols. Alfisols. Ultisols. Oxisols. Histosols. The Factors of Soil Formation----Overview. Soils in Relation to Their Parent Material. Soils in Relation to Their Age. Soils in Relation to Climate. Soils in Relation to Organisms Other Than Man. Effects of Man. Soils in Relation to Topography. Appendices. Indices.
Dip angle-compensated one-way wave equation migration

Conventional migration algorithms based on one-way wave equations in a Cartesian coordinate system often under estimate amplitudes, especially at large propagation or reflection angles. This has a deleterious effect on seismic images and should be corrected. We illustrate the nature of the problem by working in the more natural spherical coordinate system and offer two simple solutions to the problem: (1) a wave combination scheme where the wave extrapolation is done independently for each Cartesian coordinate and the resulting wavefields are summed and (2) a simple wave projection scheme whereby the conventional one-way propagator is corrected by means of a factor 1/cos(θ), where θ is the angle of the wave measured from the vertical axis or the reflector angle. The wave combination scheme is applicable to waves with propagation angles beyond 90°, but will roughly triple the computation time compared with conventional one-way propagators in the 3D case. The wave projection scheme is more economical and can easily be implemented in the wavenumber (or slowness) domain at no extra computational cost. These schemes are valid both in depth-dependent media and in laterally heterogeneous media. In addition, the proposed amplitude-preserving schemes can be applied to all methods based on the conventional one-way wave equation. We then develop and implement the second approach to demonstrate its validity by means of numerical examples.
Role of off-shelf to on-shelf transitions for East Antarctic sea ice dynamics during spring 2003

[1] During austral spring 2003, mesoscale sea ice drift and deformation off East Antarctica were investigated using in situ data from a nine-buoy array. Upon deployment, the array comprised an area of about 4000 km2 with a mean ice concentration of 96%. Half-hourly sea ice velocities were coherent across all buoys at zonal (meridional) separations of less than 160 km (70 km). Regional cross-spectral correlation was high at synoptic scales and also at semidiurnal periods off the continental shelf. Atmospheric synoptic-scale forcing explained in excess of 85% of the ice drift variability. This is significantly more than found in the Weddell Sea, where significant ice drift variability is derived from oceanic forcing. Peak frequencies of semidiurnal contributions covaried with latitude and are largely associated with the inertial response. Over the continental shelf, coincident diurnal and semidiurnal variances in ice motion arose from tidal forcing. Net divergence over 37 days resulted in an expansion to 270% of the initial area, although regional ice concentration reduced only slightly. High-frequency processes, namely inertial response and to a lesser degree tidal forcing, dominated the variability of all deformation parameters. In contrast to ice motion, low-frequency processes played a secondary role in sea ice deformation. This high-frequency dominance is similar to what has been found in the Weddell Sea, although many observations there were limited to the continental shelf, where tidal processes dominate. Sea ice motion and deformation were not affected by a seasonal transition, nor did the regional ice characteristics show any signal of seasonal change. Instead, local ice dynamics were strongly influenced by bathymetrically dependent processes.
Classification of Sweden's Forest and Alpine Vegetation Using Optical Satellite and Inventory Data

Creation of accurate vegetation maps from optical satellite data requires use of reference data to aid in interpretation or to verify map results. Reference data may be taken, for example, from field visits, aerial photo-interpretation, or ground-based inventories. National inventories are a potential source of reference data useful in land cover mapping projects. This thesis addresses aspects of mapping forest and alpine vegetation in Sweden through combined use of optical satellite data and inventory data. Issues such as reference and satellite data pre-processing, spatial scale, quantity and quality of reference data, and classification methods have been examined. Optical satellite data with pixel sizes ranging from 10 to 300 m have been used together with reference data from the Swedish National Forest Inventory (NFI), National Inventory of Landscapes in Sweden (NILS), a point sample based on the Terrestrial Habitat Monitoring program (THUF), and a forest stand database. Results include modifications to common remote sensing methods, such as introducing iterative adjustment of prior probabilities in Maximum Likelihood classification, and improved topographic normalization (C-correction) of satellite data. Probability-based samples such as NFI, NILS and THUF provide data necessary for assignment of prior probabilities, estimation of continuous values, and are useful as training and validation data. For managed boreal forest stands, coarser pixel (60 m) AWiFS data were nearly as effective for stem volume estimation as SPOT 5 data (10 m). On the other hand, the most accurate classification of detailed alpine vegetation types (72.9% overall accuracy) was from SPOT 5 data combined with elevation derivatives, while classifications of Landsat TM (25 m), AWiFS, and MERIS (300 m) were less accurate. Non-parametric methods (e.g., random forests, decision/regression trees) produced higher classification accuracies than traditional parametric methods for alpine vegetation. The quantity of reference data affected classification accuracy, as more reference data produced higher map accuracy, although other factors such as distribution and quality of the reference data should be considered. As seen in this thesis, the characteristics of the landscape exert an influence on satellite and training data requirements, classification methods and resulting map accuracy.
The SARAL/AltiKa Altimetry Satellite Mission

The India-France SARAL/AltiKa mission is the first Ka-band altimetric mission dedi-cated to oceanography. The mission objectives are primarily the observation of the oceanic mesoscales but also include coastal oceanography, global and regional sea level monitoring, data assimilation, and operational oceanography. Secondary objectives include ice sheet and inland waters monitoring. One year after launch, the results widely confirm the nominal expectations in terms of accuracy, data quality and data availability in general. Today's performances are compliant with specifications with an overall observed performance for the Sea Surface Height RMS of 3.4 cm to be compared to a 4 cm requirement. Some scientific examples are provided that illustrate some salient features of today's SARAL/AltiKa data with regard to standard altimetry: data availability, data accuracy at the mesoscales, data usefulness in costal area, over ice sheet, and for inland waters.
Sources, compositions, and distributions of water‐soluble organic nitrogen in aerosols over the China Sea

[1] Particulate water-soluble organic nitrogen (ON) was measured over the South China Sea, the Yellow Sea and at a coastal site at Qingdao in spring 2005 and 2006 to study its impact on the oceanic ecosystem over the China sea. ON contributed ∼30% of the total water-soluble particulate nitrogen over the South China Sea and ∼20% over the Yellow Sea and in Qingdao. More than 70% of the ON existed in the fine mode particles ( 2.1 μm) increased leading to an increase of that in total suspended particulates (TSP). Factor analysis indicated that ON mainly originated from anthropogenic sources while a relatively small amount was from marine and crustal sources. Urea, on the average, represented ∼8% of the total ON over the marginal sea of China. In the non-dust aerosols, ∼50% of urea existed in the fine mode over the Yellow Sea and Qingdao, but the percentage decreased to ∼30% in the dust aerosols. Free amino acids were generally a minor component of the ON, only accounting for ∼1% of the total ON.