Miracle-dz/UniFAR-FTUs huggingface dataset:
Estimating oceanic chlorophyll concentrations with neural networks

A Neural network (NN) algorithm was constructed to estimate oceanic chlorophyll concentrations from Sea-viewing Wide Field-of-view Sensor (SeaWiFS) data.The algorithm was trained and tested using sample data compiled at the SeaWiFS Bio-optical Algorithm Mini-workshop. A NN using the five visible SeaWiFS bands as inputs with ten nodes in a single hidden layer estimates chlorophyll concentrations efficiently and accurately, modelling the nonlinear transfer function between surface chlorophyll concentrations and remotely sensed reflectance data more accurately than traditional regression methods.
Sedimentation and crustal recycling along an active oblique-rift margin: Salton Trough and northern Gulf of California

Transtensional basins embedded in the San Andreas fault system of Southern California (United States) and northwestern Mexico are fi lled with sediment derived from the Colorado River, which drains a large area of the western U.S. interior. The sediment is rapidly buried, heated, and mingled with intrusions in the deep basins to form a new generation of recycled crust along the active plate boundary. Using a range of values for total basin depth, relative volume of mantle-derived intrusions, and composition of early rift deposits, the volume of Colorado River‐derived sediment in the basins is bracketed between 2.2 and 3.4 ◊ 10 5 km 3 , similar to the volume of rock that likely was eroded from the Colorado River catchment over the past 5‐6 m.y. The volumetric rate of crustal growth by sedimentation is ~80‐130 km 3 /m.y. /km, comparable to growth rates in subductionrelated island arcs and slow seafl oor spreading centers. Sedimentary and basinal processes thus play a major role in crustal evolution and recycling in this setting, and may be important at other rifted margins where a large river system is captured following tectonic collapse of a prerift orogenic highland.
Inversion for anisotropy from non‐double‐couple components of moment tensors

[1] An inversion method for retrieving seismic anisotropy from non-double-couple components of seismic moment tensors is presented. The method requires a set of highly accurate moment tensors of earthquakes that occurred in a homogeneous anisotropic focal area on differently oriented faults. In contrast to standard methods retrieving anisotropy from travel times or from shear wave splitting, which yield an overall anisotropy averaged along a whole ray path, the presented method yields a local value of anisotropy just in the focal area. The method is robust, being able to retrieve the orientation as well as strength of anisotropy even for low anisotropy symmetries as for orthorhombic symmetry. The method can utilize the moment tensors constrained to have zero trace, but using unconstrained moment tensors is advantageous. The method is applied to retrieving anisotropy in the Tonga subduction zone using moment tensors of deep-focus earthquakes reported in the Harvard centroid moment tensor catalog. The inversion is complemented by tests on synthetic data to assess its stability and the accuracy of the results. The inversion indicates that the subduction zone is anisotropic with orthorhombic symmetry. The orientation of the intra-slab anisotropy is defined by axes (azimuth/dip) a1 = 320°/54°, a2 = 121°/38°, and a3 = 223°/81°. The errors in the azimuth and dip are about 5°. The first and second axes lie along the downdip motion of the slab and along the normal to the slab, respectively. The strength of the P, S1, and S2 anisotropy is of 7.3 ± 1.5%, 13.4 ± 2.5%, and 12.6 ± 3.5%, respectively. The errors of anisotropy strength are only rough estimates, which reflect random but not systematic errors in the moment tensors used in the inversion. The values for anisotropy strength in the slab are remarkably higher than those observed in the surrounding mantle. The symmetry axes of anisotropy coincide with the principal stress directions in the slab. This manifests a primary impact of stress on anisotropy formation. The retrieved anisotropy in the slab can serve as an additional constraint on its structure and mineralogical composition.
Variability of surface layer hydrography in the tropical Pacific Ocean

The purpose of this study is to examine the variation of ocean surface layer hydrography on interannual timescales in the tropical Pacific Ocean using conductivity-temperature-depth measurements from 1976 to 1994. We demonstrate that associated with interannual variations in atmospheric forcing, there were distinct changes in mixed layer temperature, salinity, depth, and barrier layer thickness between normal, El Nino, and La Nina time periods. During El Nino a warm, fresh mixed layer accompanied by an underlying barrier layer develops in the central and eastern Pacific in association with increased precipitation and reduced trade wind forcing. Conversely, during La Nina, when unusually cold conditions prevail in the central and eastern equatorial Pacific and the warm pool is confined to the far western Pacific, a thick barrier layer is found west of 160°E. Statistically, we demonstrate that barrier layers occur with increasing frequency as mixed layer temperatures increase from 20°C to 30°C, suggesting that barrier layer thickness may be one of the factors affecting surface temperatures. The physical mechanism underlying this relationship is likely to be related to the reduced efficiency of vertical turbulent mixing in cooling the surface via entrainment of thermocline water when the barrier layer is thick. Changes in mixed layer temperature, on the other hand, can affect precipitation and therefore mixed-layer salinity, leading to the possibility of feedbacks on interannual timescales involving the mixed-layer temperature balance and the hydrologic cycle over the ocean. The extent to which such feedbacks, if operative, may influence the detailed evolution of large-scale, lower-frequency variability in the tropical Pacific needs to be critically assessed in the context of coupled ocean-atmosphere models.
Orthogonal Projection

The object of the papers is to consider two modes of representing points and lines on a spherical surface by points and lines on a plane: one method being by orthogonal projection, and the other by stereographic projection. The authors consider that students of spherical trigonometry ought to be able to accurately draw any figure with which they may have to deal, using one or other of the above methods of projection. The following propositions indicate methods of solving the various problems which would arise in connection with such accurate drawing.
Water vapor of the polar middle atmosphere: Annual variation and summer mesosphere Conditions as observed by ground‐based microwave spectroscopy

We have been operating a ground‐based microwave radiometer for the 22.235GHz water vapor line at the ALOMAR observatory, Norway, in 1995/96 and continuously since July 1997. Its high latitude location (69°N, 16°E) provides a new and unique dataset of stratospheric and mesospheric water vapor observations. We briefly describe our instrument and measuring technique and present the data of our ongoing measurements. The water vapor mixing ratio shows a pronounced annual cycle that is stronger than what has been reported for mid‐latitudes. We also present an analysis of our data for the upper mesosphere for the relationships between mesospheric water vapor, temperature, polar mesosphere summer echoes (PMSE), and noctilucent clouds (NLC) during summer months. This investigation indicates that water vapor is already present near mesopause heights when the PMSE/NLC season starts and is still present long after it has declined.
A Discrimination Algorithm for UXO Using Time Domain Electromagnetics

An assumption is made that the Time Domain Electromagnetic (TEM) response of a buried axisymmetric metallic object can be modelled as the sum of two dipoles centered at the midpoint of the body. The strength of the dipoles depends upon the relative orientation between the object and the source field, and also upon the shape and physical properties of the body. Upon termination of the source field, each dipole is assumed to decay as k(t+α)−βe−t∕γ. The parameters k, α, β and γ depend upon the conductivity, permeability, size and shape of the object, and these can be extracted from the measurements by using a nonlinear parametric inversion algorithm. Investigations carried out using an analytic solution for a sphere and laboratory measurements of steel and aluminum rectangular prisms, suggest the following two-step methodology: (1) The value of β is first used as a diagnostic to assess whether the metallic object is non-magnetic or magnetic, (2) the ratios of k1∕k2 and β1∕β2 are then diagnostic indicators as.
Implementing a dynamical ammonia emission parameterization in the large‐scale air pollution model ACDEP

[1] Currently, very simple parameterizations for the seasonal variation of the ammonia (NH3) emissions are used in most air pollution models. This limits the capability to reproduce observed seasonal variations in the NH3 concentrations in rural regions with agricultural activity. A dynamical parameterization of the temporal variation of NH3 emission for application into air pollution models has therefore been proposed. The obtained improvements are demonstrated by implementing a dynamical NH3 emission parameterization into the large-scale air pollution model ACDEP. Meteorology, information about agricultural practice, and a simple crop growth model are the basis for the parameterization. Fifteen additive functions are used to describe the different parts of the NH3 emissions from agriculture, and a 16th function is used to describe NH3 emission from catalysts used in road traffic. The new parameterization is tested by comparison of model results with NH3 measurements from Danish monitoring stations situated in agricultural areas during the years 1999–2001. Improvements in correlation coefficient of calculated diurnal mean concentrations from 0.42 to 0.70 have been achieved, and a monthly correlation coefficient up to 0.98 has been obtained for the Tange station in 2000. This validation shows that the new parameterization gives a substantial improvement in the model calculations of the NH3 concentrations in areas with high agricultural activities. Finally, the validation showed that optimum results are obtained by including a temperature correction on the gauss functions representing the emission sources.
Correction to “Using CALIPSO to explore the sensitivity to cirrus height in the infrared observations from NPOESS/VIIRS and GOES-R/ABI”

] In the paper “Using CALIPSO to explore the sensi-tivity to cirrus height in the infrared observations fromNPOESS/VIIRS and GOES‐R/ABI” by A. K. Heidingeret al. (Journal of Geophysical Research, 115, D00H20,doi:10.1029/2009JD012152, 2010), the y axis of Figure 3was scaled incorrectly. The correct version of Figure 3 isgiven here.
The magnetic properties experiments on Mars Pathfinder

The Mars Pathfinder lander carried two magnet arrays, each containing five small permanent magnets of varying strength. The magnet arrays were passively exposed to the wind borne dust on Mars. By the end of the Mars Pathfinder mission a bull's-eye pattern was visible on the four strongest magnets of the arrays showing the presence of magnetic dust particles. From the images we conclude that the dust suspended in the atmosphere is not solely single phase particles of hematite (α-Fe2O3) and that single phase particles of the ferrimagnetic minerals maghemite (γ-Fe2O3) or magnetite (Fe3O4) are not present as free particles in any appreciable amount. The material on the strongest magnets seems to be indistinguishable from the bright surface material around the lander. From X-ray fluorescence it is known that the soil consists mainly of silicates. The element iron constitutes about 13% of the soil. The particles in the airborne dust seem to be composite, containing a few percent of a strongly magnetic component. We conclude that the magnetic phase present in the airborne dust particles is most likely maghemite. The particles thus appear to consist of silicate aggregates stained or cemented by ferric oxides, some of the stain and cement being maghemite. These results imply that Fe2+ ions were leached from the bedrock, and after passing through a state as free Fe2+ ions in liquid water, the Fe2+ was oxidized to Fe3+ and then precipitated. It cannot, however, be ruled out that the magnetic particles are titanomagnetite (or titanomaghemite) occurring in palagonite, having been inherited directly from the bedrock.
Extension of runoff series using empirical orthogonal functions

Methods for extrapolating runoff series are important in order to gain maximum information from hydrological observations. The main disadvantages of traditional methods are that they are subjective and often time consuming. In this paper, empirical orthogonal functions (EOF) are adapted for the extension of time series. By a linear transformation of a set of runoff series from a region, a new set of series, EOFs, describing the runoff variations in time, and a set of weight coefficients describing the spatial variations, are created. Using this information it is possible to extend a runoff series within the region. A study has been carried out using Norwegian runoff series of daily values. The method was compared both to regression and to use of a conceptual model. In general the EOF method gives results as good as the traditional methods, and the amount of work involved is minimized while the objectivity is maximized.
Line extraction in SAR images

This paper presents a line extraction algorithm in SAR (Synthetic Aperture Radar) images. The algorithm is designed based on the statistical characteristics of the speckle in SAR image. Three steps are involved. Firstly, a new edge detector, which combines the Canny operator and Ratio operator, is used to detect the edge points and calculate their directions, then the edge points are grouped according to their edge direction to form the initial lines. Finally, a high-level grouping step connects the fragmental lines. The proposed new edge operator is CFAR (Constant False Alert Rate) and prevents the line from cleavage. The algorithm has been applied in the X-band airborne SAR images, and the results are presented at the end of this paper.
Wave propagation in poroelastic media: A velocity‐stress staggered‐grid finite‐difference method with perfectly matched layers

We present a velocity-stress staggered-grid finitedifference method to simulate wave propagation in heterogeneous poroelastic media. Biot’s theory expressed in terms of velocity and stress is to obtain a set of first order hyperbolic equations. This formulation is discretized into a staggered grid both in space and time domain with the harmonic average of the material properties to account for heterogeneous media. To simulate the wave propagation in an unbounded media, the perfectly matched layer method is used as an absorbing boundary condition. Numerical simulations of Biot’s theory show the existence of a slow P wave in porous media and are also qualitatively consistent with previous analytic predictions of the wave propagation in fluid saturated poroelastic media.
Screening for hepatitis C virus infection.

s and full-text articles were dual reviewed for inclusion or exclusion for each Key Question. Full-text articles were obtained for all studies that either investigator identified as potentially meeting inclusion criteria. Two investigators independently reviewed all full-text articles for final inclusion or exclusion. Discrepancies were resolved through discussion and consensus, and a third investigator was included in the discussion if necessary. We included randomized trials, cohort studies, and case-control studies pertinent to all Key Questions. We also included studies that reported the diagnostic accuracy of noninvasive tests for evaluating fibrosis or cirrhosis in patients with chronic HCV infection compared with liver
Mechanism of underthrusting in southwest Japan: A model of convergent plate interactions

An elastic rebound mechanism consistent with underthrusting at the time of the magnitude 8.2 Nankaido earthquake of December 21, 1946, accounts for a reversal in sense between seismic and pre-seismic changes in elevation throughout a large part of southwest Japan. This event and the magnitude 8.0 Tonankai earthquake of 1944 ruptured almost the entire boundary of the Asian and Philippine Sea plates between the Ryukyu and Izu-Bonin arcs. In terms of plate tectonics, the formation of uplifted marine terraces within the focal region of this earthquake can be explained by overriding of the Philippine Sea plate by the Asian plate as the former is consumed beneath southwest Japan. The absence of an inclined seismic zone, active volcanoes, and a well-developed deep-sea trench suggests that underthrusting in southwest Japan started in geologically recent time, possibly less than one million years ago. However, an estimated slip rate of 8±4 cm/yr suggests that typical island arc structures are rapidly evolving in this region. Similar seismic and pre-seismic movements within the focal regions of the 1960 Chilean and the 1964 Alaskan megathrusts, although based on comparatively little evidence, suggest that the inferred mechanism of underthrusting in southwest Japan is a reasonable model for interactions along other zones of plate convergence. Quasi-periodic recurrence of similar earthquake sequences in the past within each of these regions suggests that frequent monitoring of strain buildup can provide an improved measure of earthquake risk in these and other regions of underthrusting. The fault motion during the 1946 Nankaido earthquake as inferred from geodetic data was predominantly, if not entirely, dip-slip. The rupture propagated almost 300 km southwest from the epicenter along an inferred strike of N70°E and extended well beyond the limits of the after-shock zone. The leading edge of the inferred fault is assumed to break the surface on the inner wall of the Nankai trough. In order to fit the data, faults modeled as compound dislocations must be used. The preferred fault model is an underthrust dipping 30° to 40° toward the northwest. Slip calculated from a dislocation model increases from 5 to 18 meters in the direction of rupture propagation. Before the earthquake, from the 1890's to the 1930's, strain increased at a constant rate. After the earthquake, a complex pattern of movements continued for about three years at rapidly decaying rates. These movements can be explained by reversed slip on nearly the entire fault surface that ruptured during the earthquake and by delayed forward slip on the deeper parts of the fault. Mechanically these movements are interpreted as a response to underdamped slip on shallow parts and overdamped slip on deeper parts of the fault surface at the time of the main shock.
Attribution of interminima changes in the global thermosphere and ionosphere

We present a statistical attribution analysis of the changes in global annual average thermospheric mass density and ionospheric total electron content (TEC) between the cycle 22/23 solar minimum (which occurred at epoch 1996.4) and the prolonged cycle 23/24 minimum (2008.8). The mass density data are derived from orbital drag, and the TEC data are derived from ground‐based GPS receivers. The interminima change in mass density was −36% relative to the 1996.4 yearly average. Considering each multiplicative forcing independently, lower average geomagnetic activity during the cycle 23/24 minimum produced an interminima density change of at least −14%, solar extreme ultraviolet (EUV) irradiance forcing produced a density change of −1% to −13%, and changes in thermospheric CO2 concentration produced a density change of −5%. There was essentially no interminima change in global TEC derived from ground‐based GPS receivers or space‐based altimeters, even though past behavior suggests that it should have changed −3% (0.2 TEC units (1 TECU = 1016 el m−2)) in response to lower geomagnetic activity and −1% to −9% (0.1–0.8 TECU) in response to lower EUV irradiance. There is large uncertainty in the interminima change of solar EUV irradiance; the mass density and TEC data suggest a plausible range of 0% to −6%.
Cadmium Availability to Rice in Sludge‐amended Soil under “Flood” and “Nonflood” Culture

Rice plants (Oryza sativa var. ''Colusa'') were grown to maturity in pots containing a soil (Domino silt loam, pH 7.5, Xerollic calciorthid) amended with 1 percent sewage sludge enriched with variable amounts of CdSO/sub 4/ ranging up to 640 . mu.g Cd/g. Two sets of soil cultures were used, one for rice under continuous flood and the other under nonflood conditions. Grain production for rice under flood management was relatively unaffected by the Cd treatment: 25 percent yield decrement was associated with a treatment of 320 . mu.g Cd/g. Under nonflood management, however, a comparable decrement in grain production was observed with a treatment of only 17 . mu.g Cd/g. The Cd content of mature leaves at early flowering varied from approximately 0.3 . mu.g Cd/g for the controls to 2.8 . mu.g Cd/g for plants receiving the highest Cd treatments. Leaf Cd values were slightly higher under the nonflood culture. The Cd content of the grain under nonflood management was approximately 55 percent greater than that of grain under flood management. The Cd content of mature leaves correlated with grain production (r = 0.872) for rice produced under either flood or nonflood culture. Chemical analysis of saturation extracts revealed greatly reduced Cd concentrations inmore » soil solutions under flood management which may account for the greater tolerance of the cultivar to soil Cd under flood culture. This reduced availability of Cd in flooded soils is attributed to precipitation of CdS. « less
The seismic anomaly beneath Iceland extends down to the mantle transition zone and no deeper

A 3-D teleseismic tomography image of the upper mantle beneath Iceland of unprecedented resolution reveals a subvertical low wave speed anomaly that is cylindrical in the upper 250 km but tabular below this. Such a morphological transition is expected towards the bottom of a buoyant upwelling. Our observations thus suggest that magmatism at the Iceland hotspot is fed by flow rising from the mantle transition zone. This result contributes to the ongoing debate about whether the upper and lower mantles convect separately or as one. The image also suggests that material flows outwards from Iceland along the Reykjanes Ridge in the upper 200 km, but is blocked in the upper 150 km beneath the Tjornes Fracture Zone. This provides direct observational support for the theory that fracture zones dam lateral flow along ridges.
Estimating soil water retention characteristics from particle size distribution, organic matter percent, and bulk density

Regression models are presented for estimating soil-water-retention curves from particle-size distribution, percentage of organic matter, and bulk density. Models were developed from the measured soil-water-retention curves of artificially packed cores (7.6×7.6 cm) of 43 soil materials. These soil materials included 13 agricultural soils. Curves predicted with these models approximated reasonably well the measured water retention of 61 Missouri soils. Because conventional methods of obtaining retention curves are expensive and time consuming, these equations will be valuable for modeling salt and water flow in soils and for estimating available water capacities.