Miracle-dz/UniFAR-FTUs huggingface dataset:
A reformulation of Horton's Laws for large river networks in terms of statistical self‐similarity

The well‐known Norton's laws are empirical observations on how the means of measurements for river networks and basins vary with Horton‐Strahler order. It is now known that these laws are a consequence of an average‐sense self‐similarity in the bifurcation structure of river networks. In this paper we present a reformulation of Horton's laws which generalizes the familiar scaling of first moments, or means, to scaling of entire distributions. We also present extensive data analysis which supports this reformulation and show that this feature is also exhibited by Shreve's well‐known random topology model.
An ensemble approach to the representation of subgrid-scale heterogeneity of crop phenology and yield in coarse-resolution large-area crop models

The grid interval of a global climate model (GCM) is generally hundreds of kilometers in latitude and longitude. The spatial heterogeneity of crop condition (e.g., phenology and yields) at that scale could be substantial. Because the atmosphere-cropland exchanges of energy, water, and materials are sensitive to crop condition, this issue poses a question: How can we simulate the condition of a crop of interest on a GCM grid scale while taking into account the spatial heterogeneity of crop condition at a sub-grid scale? We therefore proposed an ensemble approach that uses stochastic parameter values to represent the spatial variation in the phenological and biophysical characteristics of a crop within a given GCM grid box, and tested its feasibility with simulation experiments. The combination of the Soil and Water Assessment Tool (SWAT) applied to maize in the Central Great Plains, United States, and coarse-resolution (2.5×2.5) reanalysis data was taken as the example. The ensemble simulations successfully captured the spatial variation in the phenology and yield. Our conclusion is that the ensemble approach is feasible and expected to benefit large-area crop modeling when extending those models to include more information on the spatial heterogeneity of crop condition than ever.
Dehydration melting of ultrahigh‐pressure eclogite in the Dabie orogen: evidence from multiphase solid inclusions in garnet

Several types of multiphase solid (MS) inclusions are identified in garnet from ultrahigh‐pressure (UHP) eclogite in the Dabie orogen. The mineralogy of MS inclusions ranges from pure K‐feldspar to pure quartz, with predominance of intermediate types consisting of K‐feldspar + quartz ± silicate (plagioclase or epidote) ± barite. The typical MS inclusions are usually surrounded with radial cracks in the host garnet, similar to where garnet contains relict coesite. Barite aggregates display significant heterogeneity in major element composition, with total contents of only 57–73% and highly variable SiO2 contents of 0.32–25.85% that are positively correlated with BaO and SO3 contents. The occurrence of MS inclusions provides petrographic evidence for partial melting in the UHP metamorphic rock. The occurrence of barite aggregates with variably high SiO2 contents suggests the coexistence of aqueous fluid with hydrous melt under HP eclogite facies conditions. Thus, local dehydration melting is inferred to take place inside the UHP metamorphic slice during continental collision. This is ascribed to phengite breakdown during ‘hot’ exhumation of the deeply subducted continental crust. As a consequence, the aqueous fluid is internally buffered in chemical composition and its local sink is a basic trigger to the partial melting during the continental subduction‐zone metamorphism.
Frequencies of future extreme events under conditions of changing hydrologic regime

Estimating the future frequency of extreme hydrologic events remains a common problem. Present procedures use hydrologic records to estimate future frequencies of occurrence, assuming that hydrologic regimes are stationary, despite contrary evidence in South America. This paper is concerned with estimating frequencies of hydrologic extremes under conditions for which trends in hydrologic regime have been detected, and where it is not unreasonable to suppose that such trends will continue into the near future. Expressions are given (i) for the probability that a given critical extreme Qcrit (a critical flood discharge, for example) will occur at least once in the next K years, when trend has been found in the sequence of annual extreme values; (ii) for the probability that a peak flood equal to or larger than Qcrit will occur at least once during a period [0,T) where the 'peaks‐over‐threshold' method is used.
Evolution of the storm magnetic field disturbance around Earth's surface and the associated ring current as deduced from multiple ground observatories

Based on the continuous magnetic measurements of the multiple ground observatories, the structure of the geomagnetic field disturbance and its temporal variations have been investigated, and the evolution of the storm ring current is deduced accordingly. Assuming that the geomagnetic disturbance around the Earth's surface is approximately linearly varying in space, the spatial gradient of the corrected H (geomagnetic horizontal) component can be obtained from the multiple ground observations. It is found that the maximum difference of the corrected H component around the Earth's surface, as calculated by the gradient of the corrected H component multiplied by the Earth diameter, represents well the asymmetric index Asy‐H. The antidirection of the gradient of the corrected H component can be regarded as pointing to the position of the maximum partial ring current. It is shown that for ordinary magnetic storms with Dst > −200 nT, the maximum partial ring current is located around the duskside during the main phase and the earlier stage of the recovery phase. At the later stage of the recovery phase, the position of the maximum partial ring current can possibly keep rotating eastward, indicating that the energetic electrons may play a significant role and the main ring current carriers may be the electrons at this stage. For the super storms (Dst < −200 nT), the position of the maximum partial ring current is not as regular. Based on physical considerations, this investigation also provides new formulas of the definitions to the symmetric index Sym‐H and asymmetric index Asy‐H.
The Astronomical Theory of Climatic Change: Barbados Data

The island of Barbados, West Indies, was an area of tectonic emergence during the Pleistocene. As Barbados was uplifted, reef tracts formed around the island. The interaction of gradual tectonic uplift of the island and glacio-eustatic sea level fluctuations has resulted in the formation of a complex, terraced "coral cap. " Each individual terrace represents an elevated reef tract and is therefore constructional rather than erosional in origin. Subsequent to formation, the reef terraces have been abraded by waves and subjected to minor faulting; in particular, wave abrasion has extensively modified the morphology of some of the terraces. Radiometric dating of successive reef terraces suggests periods of high sea level and associated individual reef tract developments about 82,000, 105,000, and 125,000 years ago. The next higher group of terraces was formed between 170,000 and 230,000 years ago; the rest of the terraces were formed more than 250,000 years ago. Marked interruptions in the development of well-defined reef terraces from Recent to 80,000 years ago and from 130,000 to 170,000 years ago apparently record prolonged periods of relatively low sea level. The ages of the reef terraces compare closely with times of maximum summer solar radiation in the Northern hemisphere and therefore lend strong support to the astronomical theory of climatic change.
Rupture propagation with finite stress in antiplane strain

Rupture propagation in antiplane strain is investigated by using both analytic and numerical methods. Under the assumption that a solid will absorb energy irreversibly when it is strained at a sufficiently large shear stress it is found that energy must be absorbed at the rupture front in addition to the work done against the sliding friction stress. The energy absorbed increases with propagation distance, so it is not negligible at any length scale and is much larger than the ideal surface energy of molecular cohesion. The concept of a critical crack length carries over to the case of a finite stress-slip law on a fault plane but does not carry over to a homogeneous inelastic medium. In a dynamic slip event, while a typical value of particle velocity is proportional to stress drop, the peak value near the fault is proportional to material strength.
Short wave damping in the simultaneous presence of a surface film and turbulence

Spatial decay rates of short gravity waves and gravity-capillary waves in the frequency range of 3 to 8 Hz were measured in a laboratory wave tank equipped with a submerged oscillating grid to generate turbulence. Experiments were conducted with: clean fresh water, fresh water with an oleyl alcohol insoluble surfactant surface film, fresh water with a Triton X-100 soluble surfactant surface film, and with sea water having a surface film of its own natural surfactants. With each material, decay rate tests were conducted with and without turbulence. The principal purpose of the study was to determine the extent to which turbulence modified the wave decay due to the presence of surface films. This is of importance for modeling the energy balance of short sea waves which influence microwave backscattering used for remote sensing of the ocean. The results show that the wave decay rate is equal to the sum of the rates due to surfactant alone and with turbulence alone. It is concluded that the statistically stationary component of the turbulence that exists near the free surface does not significantly modify the decay mechanism associated with the presence of the surfactant.
Similarity and length scale for spatially varied overland flow.

One-dimensional finite element models enable physically based investigations of overland flow generated under spatially varied surface slope, width, roughness, and excess rainfall intensity. Simulated results of 8400 dimensionless hydrographs under spatially varied input parameters indicate that runoff discharge variations depend primarily on the ratio of rainfall duration tr to the time to equilibrium te. Peak discharge distributions change drastically as the dimensionless rainfall duration tr/te approaches unity. Similarity conditions exist for all four parameters regardless of whether the spatial variability is correlated or uncorrelated. A length scale function of not only the spatially averaged values of surface parameters but also depending on rainstorm duration and intensity delineates similarity conditions for spatially varied surface runoff. For surface runoff lengths much shorter than this length scale, the rainfall-runoff relationship becomes nearly independent of the spatial variability in hydrologic parameters. Conversely, for surface runoff lengths exceeding the length scale, the rainfall-runoff relationship is sensitive to spatial variability. This length scale can serve as a basis for the determination of grid sizes in hydrologic models.
Paleomagnetism of an east‐west transect across the Cascade arc in southern Washington: Implications for regional tectonism

Paleomagnetic data from a transect across the Cascade arc in southern Washington were collected to test models of vertical axis rotations for this part of the Pacific Northwest and to provide information on the tectonic history of the St. Helens seismic zone. The 75 site-mean directions are divided into three groups based on isotopic, fission track, and stratigraphic ages. Group 1 consists of samples from rocks deposited between 39 and 30 Ma and shows a mean clockwise vertical axis rotation of 34° ± 13°, group 2 consists of samples from rocks deposited between 30 and 24 Ma and shows a mean clockwise rotation of 17° ± 11°, and group 3 consists of samples from rocks between 24 and 16 Ma and shows a mean clockwise rotation of 20° ± 12°. Although these three values of rotation are statistically indistinguishable at the 95% confidence level, we interpret them in combination with other data to indicate differential rotation across the St. Helens seismic zone (SHZ). The available paleomagnetic data for Eocene-Oligocene rocks west of the seismic zone show clockwise vertical axis rotations of 30° ± 8° and 35° ± 9° consistent with the value for group 1. The rotational values for groups 2 and 3 and the intrusive suite of Kidd Creek (13 Ma), despite their different ages, have similar values east of the SHZ. Comparing these groups of data east and west of the seismic zone indicates a differential rotation of 10° ± 3° across it. In addition, the rates of rotation in southern Washington are similar to those for rocks in the western Cascades of Oregon and indicate that rotational deformation of Miocene age extends northward into southern Washington and eastward into the axis of the arc.
Backscattering ratio variation and its implications for studying particle composition: A case study in Yellow and East China seas

[1] Using in situ optical measurements collected during the 2003 spring cruise over the Yellow and East China seas, the particle backscattering ratio is calculated and spectral variability is analyzed by means of geometric mean regression. The analysis shows that the particle backscattering ratio can be regarded as wavelength-independent in the range of 442–676 nm, given the measurement uncertainties associated with the backscattering and scattering data. The backscattering ratio and attenuation measurements are used to calculate the particle refractive index, which is related to the particle composition. The distributions of the particle refractive index and the water component concentration along two transects suggest the feasibility for studying the particle composition.
Atmospheric tide: 2. The solar and lunar semidiurnal components

Solar and lunar semidiurnal wind and temperature oscillations from the surface to 400 km are simulated for average solar activity conditions utilizing the numerical tidal model described in part 1. Hough mode decomposition of the solstitial solar semidiurnal tide excited by H2O and O3 insolation absorption below 80 km indicates that it is characterized by a predominance of (2, 2) below 60 km; about equal contributions of (2, 2), (2, 3), and (2, 4) between 70 and 90 km; mostly (2, 4) with some (2, 5) and (2, 2) between 90 and 120 km; and a predominance of (2, 2) above 140 km with secondary contributions from (2, 3) and (2, 5). The solstitial lunar semidiurnal tide is characterized by a predominance of (2, 2) below 70 km; (2, 4) with secondary contributions from (2, 2), (2, 3), and (2, 5) between 80 and 110 km; and by (2, 2) with a fairly strong secondary contribution from (2, 3) above 120 km. Similar descriptions for both the solar and lunar oscillations apply at equinox, except that the asymmetric (2, 3) and (2, 5) modes are absent. Relative to the solar component, lunar temperature and wind amplitudes are sufficiently large (∼20%) in the lower and upper thermosphere to account for some of the observed variability previously attributed to the solar tide. Amplitudes of the (2, 4) and (2, 5) modes above 100 km are significantly affected by mesospheric eddy diffusion coefficients in excess of 2×106 cm² s−1. The total solar semidiurnal exospheric temperature oscillation for average solar conditions ranges from ∼10–20°K poleward of 40°N to ∼40–60°K equatorward of 30°N and has its origin in three sources of excitation all of comparable importance: (1) EUV solar radiation absorption in the lower thermosphere (100–200 km), (2) in situ momentum coupling due to the interaction of diurnal winds and diurnally-varying ion drag, and (3) tides propagating upwards from below 100 km. In addition, the calculations are compared with rocket, meteor radar, partial reflection, Thomson scatter, and satellite data to evaluate the consistency of the model with observations.
Estimation of chlorophyll‐a concentration and trophic states for inland lakes in Northeast China from Landsat TM data and field spectral measurements

Landsat TM data and field spectral measurements were used to evaluate chlorophyll‐a (Chl‐a) concentration levels and trophic states for three inland lakes in Northeast China. Chl‐a levels were estimated applying regression analysis in the study. The results obtained from the field reflectance spectra indicate that the ratio between the reflectance peak at 700 nm and the reflectance minimum at 670 nm provides a relatively stable correlation with Chl‐a concentration. Their determination of coefficients R 2 is 0.69 for three lakes in the area. From Landsat TM data, the results show that the most successful Chl‐a was estimated from TM3/TM2 with R 2 = 0.63 for the two lakes on 26 July 2004, from TM4/TM3 with R 2 = 0.89 for the two lakes on 14 October 2004, and from the average of TM2, TM3 and TM4 with R 2 = 0.72 for the three lakes tested on 13 July 2005. These results are applicable to estimate Chl‐a from satellite‐based observations in the area. We also evaluate the trophic states of the three lakes in the region by employing Shu's modified trophic state index (TSIM) for the Chinese lakes' eutrophication assessment. Our study presents the TSIM from different TM data with R 2 more than 0.73. The study shows that satellite observations are effectively applied to estimate Chl‐a levels and trophic states for inland lakes in the area.
Active tectonics, seismicity and geomorphology with special reference to Normandy (France)

Integrated studies based on tectonic, seismotectonic and geomorphological analyses indicate that Normandy (northwest France) has been an active area during the Quaternary. Topography and landform discontinuities reflect the dislocation and differential uplift of a late Cenozoic platform. The tectonic activity is represented by (i) active faults, indicated by linear scarps and seismic activity, (ii) offsetting of pre-existing surfaces, (iii) Plio-Pleistocene sedimen- tation restricted within narrow subsiding zones, and (iv) morphometric properties of drainage basins that indicate zones of differential uplift. The inferred strain pattern involves (i) a shortening direction that strikes NW-SE as expected in the European context of Alpine compression, and (ii) a NE-SW trending extension accommodated by NW-SE normal faults. The geomorphological systems encountered in Normandy preferentially record differential vertical displacements. Copy- right © 2000 John Wiley & Sons, Ltd.
Annual push moraines as climate proxy

We reconstruct the terminus position of a mountain glacier in British Columbia, Canada from annual push moraines formed between 1959 and 2007. Our reconstruction represents the longest, annually‐resolved record of length change for a North American glacier. Comparison of annual recession with climate records indicates that glacier recession is controlled by air temperatures during the ablation season and accumulation season precipitation during the previous decade. Analysis among records of glacier frontal variation and mass balance in western North America similarly reveals an immediate terminus reaction to summer and net balance and a delayed reaction to winter and net balance. Other mountain ranges may contain long series of push moraines that could be exploited as climate proxies, and to improve understanding of glacier response to climate.
Turbulence structure in a river reach with sand bed

Measurements and analysis of the three‐dimensional turbulence structure in a straight lowland river reach are presented. Accurate measurements of velocity profiles were taken with an acoustic Doppier velocimeter (ADV) and a multichannel micropropeller‐based system. It is shown that analytical expressions derived from investigations of laboratory open‐channel flows agree well with the measured data only in the central part of the river where flow can be considered weakly three‐dimensional. At the same time, clear differences of empirical parameters between river and laboratory flows are detected. It was established that river turbulence is isotropic for spatial scales smaller than the river depth. The data also allowed the detection and analysis of the turbulence anisotropy impact on the formation of secondary currents. Special attention is paid to the investigation of coherent structures. Their spatial scales were evaluated applying the conditional‐average procedure based on uw quadrant analysis. On average the scales of ejection and sweep events are as large as 1.5 times the flow depth.
Facies architecture of alluvial floodbasin deposits: three‐dimensional data from the Upper Triassic Callide Coal Measures of east‐central Queensland, Australia

A detailed investigation of floodbasin facies architecture was undertaken in the Upper Triassic (Carnian-Rhaetian) Callide Coal Measures in east-central Queensland, Australia, using extensive highwall and exploration borehole data from ongoing mining activities. The composite Callide Seam Member varies up to 23 m in thickness and is locally split by a number of clastic partings up to several metres thick, ranging from claystone to coarse sandstone. A subset of the nine lithofacies recognized in surface exposures was identified from geologists' logs of cored and uncored drillholes through the Callide Seam Member. Facies mapping of each clastic parting (split) was then undertaken using all available highwall and drilling data. Sequential maps of facies and interval thickness for each coal body and clastic parting over the mine area (6000 × 2500 m) record sediment accumulation in alluvial channel and floodbasin environments (including levees, splays and splay complexes, and mires). The maps indicate that the numerous splays have dominantly elongate plan geometry (up to 4 km long), with lesser irregular and rare lobate shapes. Small, elongate splays were evidently formed during single flood events, whereas larger, elongate bodies and more irregularly shaped complexes were the product of longer-term splay construction over several flood cycles. Quantitative summaries of splay dimensions indicate a wide variety of shape and size. The distribution of splay orientations is similar to the palaeocurrent distribution in major alluvial channel deposits as established from cross-bedding. Alluvial channels that sourced the splays and other clastic sediments within seam splits were of low sinuosity, braided planform, constructed sediment bodies up to 2800 m wide and were dominantly loaded rather than incised into underlying peat-rich substrates.