Miracle-dz/UniFAR-FTUs huggingface dataset:
Cumulative probability functions and their role in evaluating the chronology of geomorphological events during the Holocene

Cumulative probability functions (CPFs) for large numbers of radiocarbon age determinations are increasingly being used by scientists as a methodology to discern environmental histories. While the recent compilation of regional databases of the radiocarbon dating control for fluvial sediment sequences has been beneficial for identifying gaps in knowledge and stimulating new research, there are a number of problems that critically undermine the use of these CPFs as sensitive hydroclimatic proxies. (i) The CPF method is underpinned by the assumption that each radiocarbon measurement is a true age estimate for a point in time, whereas each measured age in fact forms a scatter around the true age of the sample; (ii) calibration of radiocarbon ages is responsible for much of the structure in CPFs and compounds the problem of scatter and smears the chronological control; (iii) the databases incorporate multiple types of environmental changes differing chronological relationships between the 14C measurements and the dated events, with pre‐dating, dating or post‐dating chronological control each displaying variable length temporal lags all mixed together in the same analysis; and (iv) the radiocarbon ages from individual case studies need to be more robustly tested before being incorporated into regional databases. All these factors negate the value of CPFs as sensitive proxies of environmental change, because peaks in probability for individual radiocarbon measurements are likely to be an incorrect estimate for the age of a geomorphological event and this problem is compounded by combining probabilities for multiple unrelated events. In this paper we present a critical analysis of CPFs and their interpretation before suggesting alternative approaches to analysing radiocarbon geochronologies of geomorphic events, which include: (i) Bayesian age modelling of river terrace development; (ii) developing regional databases that test specific geomorphic hypotheses; (iii) Bayesian age modelling of palaeoflood records; and (iv) analysis of sedimentation rates. Copyright © 2011 John Wiley & Sons, Ltd.
Transfer of satellite rainfall error from gaged to ungaged locations: How realistic will it be for the Global Precipitation Mission?

In this study, we investigate the fundamental open question facing the satellite rainfall data community today ‐ If “error” is defined on the basis of independent ground validation (GV) rainfall data, how are these error metrics estimated for a satellite rainfall data product without the need for much extensive GV data? Using a six‐year database of high resolution (0.25 degree and 3 hourly) satellite rainfall data over the United States and an optimal spatial interpolation method (ordinary kriging), we demonstrate that most error metrics (such as bias and probability of detection) are amenable for ‘transfer’ from gaged to ungaged locations than others. Our findings also indicate that a continuously‐calibrated and regionalized error transfer scheme is technically feasible within the neighborhood of a gaged region if more research is carried out on the role played by different interpolation methods and the temporal structure of error.
Crystal structures of three 1-oxo-1,2-dihydronaphthalene derivatives: dimethyl 4-(4-methoxyphenyl)-2-(4-methylphenyl)-1-oxo-1,2-dihydronaphthalene-2,3-dicarboxylate, dimethyl 1-oxo-2-(pyren-4-yl)-4-(thiophen-2-yl)-1,2-dihydronaphthalene-2,3-dicarboxylate and ethyl 1-oxo-2-phenyl-2,4-bis(thiophen-2-y

In the title 1-oxo-1,2-dihydronaphthalene derivatives, the cyclohexa-1,3-diene rings of the 1,2-dihydronaphthalene ring systems adopt half-chair, boat and half-chair conformations, respectively. In the crystal of the methylphenyl compound, the molecules are linked via C—H⋯O, C—H⋯π and π–π interactions, forming a double-chain structure, while in the crystals of the other two compounds, molecules are linked by π–π interactions, forming a chain structure.
Neurocognitive Outcome of Children Exposed to Perinatal Mother-to-Child Chikungunya Virus Infection: The CHIMERE Cohort Study on Reunion Island

Background Little is known about the neurocognitive outcome in children exposed to perinatal mother-to-child Chikungunya virus (p-CHIKV) infection. Methods The CHIMERE ambispective cohort study compared the neurocognitive function of 33 p-CHIKV-infected children (all but one enrolled retrospectively) at around two years of age with 135 uninfected peers (all enrolled prospectively). Psychomotor development was assessed using the revised Brunet-Lezine scale, examiners blinded to infectious status. Development quotients (DQ) with subscores covering movement/posture, coordination, language, sociability skills were calculated. Predictors of global neurodevelopmental delay (GND, DQ≤85), were investigated using multivariate Poisson regression modeling. Neuroradiologic follow-up using magnetic resonance imaging (MRI) scans was proposed for most of the children with severe forms. Results The mean DQ score was 86.3 (95%CI: 81.0–91.5) in infected children compared to 100.2 (95%CI: 98.0–102.5) in uninfected peers (P<0.001). Fifty-one percent (n = 17) of infected children had a GND compared to 15% (n = 21) of uninfected children (P<0.001). Specific neurocognitive delays in p-CHIKV-infected children were as follows: coordination and language (57%), sociability (36%), movement/posture (27%). After adjustment for maternal social situation, small for gestational age, and head circumference, p-CHIKV infection was found associated with GND (incidence rate ratio: 2.79, 95%CI: 1.45–5.34). Further adjustments on gestational age or breastfeeding did not change the independent effect of CHIKV infection on neurocognitive outcome. The mean DQ of p-CHIKV-infected children was lower in severe encephalopathic children than in non-severe children (77.6 versus 91.2, P<0.001). Of the 12 cases of CHIKV neonatal encephalopathy, five developed a microcephaly (head circumference <−2 standard deviations) and four matched the definition of cerebral palsy. MRI scans showed severe restrictions of white matter areas, predominant in the frontal lobes in these children. Conclusions The neurocognitive outcome of children exposed to perinatal mother-to-child CHIKV infection is poor. Severe CHIKV neonatal encephalopathy is associated with an even poorer outcome.
Pinatubo and pre‐Pinatubo optical‐depth spectra: Mauna Loa measurements, comparisons, inferred particle size distributions, radiative effects, and relationship to lidar data

The Ames airborne tracking sunphotometer was operated at the National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory (MLO) in 1991 and 1992 along with the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) automated tracking sunphotometer and lidar. June 1991 measurements provided calibrations, optical-depth spectra, and intercomparisons under relatively clean conditions; later measurements provided spectra and comparisons for the Pinatubo cloud plus calibration checks. June 1991 results are similar to previous MLO springtime measurements, with midvisible particle optical depth τp(λ = 0.526μm) at the near-background level of 0.012 ± 0.006 and no significant wavelength dependence in the measured range (λ = 0.38 to 1.06μm). The arrival of the Pinatubo cloud in July 1991 increased midvisible particle optical depth by more than an order of magnitude and changed the spectral shape of τp(λ) to an approximate power law with an exponent of about −1.4. By early September 1991, the spectrum was broadly peaked near 0.5 μm, and by July 1992, it was peaked near 0.8 μm. Our optical-depth spectra include corrections for diffuse light which increase postvolcanic midvisible τp values by 1 to 3% (i.e., 0.0015 to 0.0023). NOAA- and Ames Research Center (ARC)-measured spectra are in good agreement. Columnar size distributions inverted from the spectra show that the initial (July 1991) post-Pinatubo cloud was relatively rich in small particles (r<0.25μm), which were progressively depleted in the August-September 1991 and July 1992 periods. Conversely, both of the later periods had more of the optically efficient medium-sized particles (0.25<r<1 μm) than did the fresh July 1991 cloud. These changes are consistent with particle growth by condensation and coagulation. The effective, or area-weighted, radius increased from 0.22 ± 0. 06μm in July 1991 to 0.56 ± 0.12 μm in August-September 1991 and to 0.86 ± 0.29 μm in July 1992. Corresponding column mass values were 4.8 ± 0.7, 9.1 ± 2.7, and 5.5 ± 2.0 μg/cm2, and corresponding column surface areas were 4.4 ± 0.5, 2.9 ± 0.2, and 1.1 ± 0.1 μm2/cm2. Photometer-inferred column backscatter values agree with those measured by the CMDL lidar on nearby nights. Combining lidar-measured backscatter profiles with photometer-derived backscatter-to-area ratios gives peak particle areas that could cause rapid heterogeneous loss of ozone, given sufficiently low particle acidity and suitable solar zenith angles (achieved at mid- to high latitudes). Top-of-troposphere radiative forcings for the September 1991 and July 1992 optical depths and size distributions over MLO are about −5 and −3 W m−2, respectively (hence comparable in magnitude but opposite in sign to the radiative forcing caused by the increase in manmade greenhouse gases since the industrial revolution). Heating rates in the Pinatubo layer over MLO are 0.55 ± 0.13 and 0.41 ± 0.14 K d−1 for September 1991 and July 1992, respectively.
The value of satellite‐derived snow cover images for calibrating a hydrological model in snow‐dominated catchments in Central Asia

Including satellite‐derived snow cover data for hydrologic model calibration can be a good way to improve model internal consistency. This study applied a multiobjective genetic algorithm to characterize the trade‐off curve between model performance in terms of discharge and snow cover area (SCA). Using a Monte Carlo‐based approach, we further investigated the additional information content of an increasing number of SCA scenes used in the calibration period. The study was performed in six snowmelt‐dominated headwater catchments of the Karadarya Basin in Kyrgyzstan, Central Asia, using the hydrological model WASA and snow cover data from four melt seasons retrieved from AVHRR (Advanced Very High Resolution Radiometer). We generally found only small trade‐offs between good simulations with respect to discharge and SCA, but good model performance with respect to discharge did not exclude low performance in terms of SCA. On average, the snow cover error in the validation period could be reduced by very few images in the calibration period. Increasing the number of images resulted in only small further improvements. However, using only a small number of images involves the risk that these particular images cause the selection of parameter sets which are not representative for the catchment. It is therefore advisable to use a larger number of images. In this study, it was necessary to include at least 10–16 images.
Aerosol optical depth over the mountainous region in central Asia (Issyk‐Kul Lake, Kyrgyzstan)

Aerosol optical depth measurements over Issyk‐Kul Lake acquired with the handheld sun photometer Microtops II are analyzed. Aerosol found over the mountainous region at the elevation of 1650 m above sea level resembles mostly clean background conditions. The yearly aerosol optical depth at a wavelength 500 nm ∼0.10 ± 0.03 is in agreement with the multi‐year means from the background sites of the Aerosol Robotic Network (AERONET). Over a period of 4 years optical depth showed a seasonal pattern, with a maximum observed during summer. A link has been made between new and previously acquired data in order to provide a reliable trend for the region.
The thickness distribution of sea ice and snow cover during late winter in the Bellingshausen and Amundsen Seas, Antarctica

Data collected from a voyage of RV Nathaniel B. Palmer to the Bellingshausen and Amundsen Seas during August–September 1993 are used to investigate the thickness distribution of sea ice and snow cover and the processes that influence the development of the first-year pack ice. The data are a combination of in situ and ship-based measurements and show that the process of floe thickening is highly dependent on ice deformation; in particular, rafting and ridging play important roles at different stages of floe development. Rafting is the major mechanism in the early stages of development, and core structure data show the mean thickness of individual layers of crystals to be only 0.12 m. Most ice 0.6 m having some surface deformation. Blocks within ridge sails are typically in the range 0.3–0.6 m thick, and ship-based observations estimate approximately 25% of the pack exhibits surface ridging. When corrected for biases in the observational methods, the data show that the dominant ice and snow thickness categories are >0.7 m and 0.2–0.5 m, respectively, and account for 40% and 36% of the surface area of the pack ice. Approximately 8% of the pack is open water. An estimate of the effects of ridging on the distribution of ice mass within the pack suggests that between 50 and 75% of the total mass is contained within the 25% of the pack that exhibits surface ridging.
A field‐scale infiltration model accounting for spatial heterogeneity of rainfall and soil saturated hydraulic conductivity

This study first explores the role of spatial heterogeneity, in both the saturated hydraulic conductivity Ks and rainfall intensity r, on the integrated hydrological response of a natural slope. On this basis, a mathematical model for estimating the expected areal‐average infiltration is then formulated. Both Ks and r are considered as random variables with assessed probability density functions. The model relies upon a semi‐analytical component, which describes the directly infiltrated rainfall, and an empirical component, which accounts further for the infiltration of surface water running downslope into pervious soils (the run‐on effect). Monte Carlo simulations over a clay loam soil and a sandy loam soil were performed for constructing the ensemble averages of field‐scale infiltration used for model validation. The model produced very accurate estimates of the expected field‐scale infiltration rate, as well as of the outflow generated by significant rainfall events. Furthermore, the two model components were found to interact appropriately for different weights of the two infiltration mechanisms involved. Copyright © 2005 John Wiley & Sons, Ltd.
Vital effects in coral skeletal composition display strict three‐dimensional control

Biological control over coral skeletal composition is poorly understood but critically important to paleo‐environmental reconstructions. We present micro‐analytical measurements of trace‐element abundances as well as oxygen and carbon isotopic compositions of individual skeletal components in the zooxanthellate coral Colpophyllia sp. Our data show that centers of calcification (COC) have higher trace element concentrations and distinctly lighter isotopic compositions than the fibrous components of the skeleton. These observations necessitate that COC and the fibrous skeleton are precipitated by different mechanisms, which are controlled by specialized domains of the calicoblastic cell‐layer. Biological processes control the composition of the skeleton even at the ultra‐structure level.
Simulating the Holocene Lake-Level Record of Lake Bysjön, Southern Sweden

Lake Bysjön, southern Sweden, has experienced major lake-level lowerings during the Holocene, with one interval about 9000 14C yr B.P. when water level dropped ca. 7 m and the lake became closed. These changes were not solely due to known changes in radiation budgets or seasonal temperatures. Simulations with a lake-catchment model indicate that, given the actual changes in radiation and temperatures, all the observed lake-level lowerings (including the major lowering at 9000 14C yr B.P.) could have occurred in response to precipitation changes of <75 mm/yr when winter temperatures were warmer than today. In these circumstances, the reduction of runoff into the lake caused by increased evapotranspiration during the late winter and spring, combined with relatively small changes in precipitation, was sufficient for the lake to become closed. When winter temperatures were colder than today, the reduction in winter runoff related to reduced precipitation was only very slight and insufficient to lower the lake below threshold. In such circumstances, changes in outflow were sufficient to compensate for the combined changes in precipitation and runoff, and lake level therefore remained unchanged.
Two novel methods for field measurements of hydrodynamic density of floodplain vegetation using terrestrial laser scanning and digital parallel photography

Hydrodynamic vegetation density, the sum of the projected plant area per unit volume, is an important parameter for floodplain flow models. This paper compares two novel techniques to quantify this parameter in the field: terrestrial laser scanning (TLS) and digital parallel photography (PP). Separate field reference data were collected for the two methods, which consisted of (1) a stem map of 650 trees, aggregated into 23 plots in a single forest patch, (2) 17 manually measured forest plots in two floodplains. PP consists of a series of digital photographic images of vegetation against a contrasting background. The centre columns of all images were merged into a single composite parallel image. This mosaic was thresholded to determine the fractional coverage of the vegetation, which is converted to vegetation density using the optical point quadrat method. A sensitivity analysis proved that PP is insensitive to small errors on the selected number of centre columns, photograph spacing should not exceed 20 cm, photograph resolution is important and the plot depth should be measured accurately. TLS was carried out using a Leica HDS3000 time‐of‐flight laser scanner. Data processing of TLS data consisted of slicing the points around breast height. In a polar grid the vegetation density was predicted using the optical point quadrat method, corrected for missing points. Both methods were compared to the field reference data. PP (EF = 0.99; bias = 8.4×10−5 m−1) showed a higher modelling efficiency than the TLS method (EF = 0.63; bias = 0.015 m−1). An advantage of the TLS method is the ability to provide a detailed 2‐dimensional or even 3‐dimensional distribution of vegetation density. PP is cheaper, faster, and data processing is limited. We conclude that TLS and PP are two complementary techniques that show high accuracies for field measurements of vegetation density.
Small net carbon dioxide uptake by Russian forests during 1981–1999

A permafrost‐enhanced biogeochemical process model using observed climate and CO2 data, and satellite‐observed maps of forest composition and density predicts a moderate biomass increment and carbon sink of 74 and 131 Tg carbon per year (TgC/a) in the Russian forests during 1981–1999. The enhanced process model realistically represents ecosystem state in terms of river runoff, area burned by fires, vegetation productivity and biomass, in comparison to monitoring and inventory data. Rising atmospheric CO2 content is found to have been the main cause of the carbon sink. Amounting to 7% of carbon emissions from fossil fuel emissions in Eurasia, our results demonstrate a limited capability of the Russian boreal forest in its current state to compensate anthropogenic carbon emissions.
On the efficiency of vertical array aeolian field traps

The efficiency of three vertical array field traps for measuring the distribution of aeolian mass transport with height was compared with measurements with an isokinetic trap. The vertical traps seem to work adequately (efficiency > 80%) at heights greater than ≈15 mm above the bed. Closer to the bed, however, the open array trap catches about 70%, the two continuous arrays only about 50%. Because most of the transport takes place close to the surface, the overall efficiency of the field traps ranges from 50 to 70%.
Reducing Velocity Model Uncertainty and Improving Microseismic Event Location Accuracy: Crosswell Seismic Tomography using a Repeatable Downhole Sparker Source

Velocity model errors are a major source of uncertainty in microseismic event location – a source of uncertainty that often goes unaddressed. This paper demonstrates how a commercial downhole sparker source can be used to produce crosswell tomography surveys that result in much improved velocity profiles. The combination of improved velocity model and more accurate event time picking deliver a much more constrained error distribution of micro seismic event location. This paper will outline a description of a repeatable and broadband downhole source, and the expected improvement to event location accuracy which is likely to be achieved, along with suggestions on how this may be applied to future monitoring surveys.
Fractional-order derivative and time-dependent viscoelastic behaviour of rocks and minerals

A general constitutive equation for viscoelastic behaviour of rocks and minerals with fractional-order derivative is investigated. This constitutive law is derived based on differential geometry and thermodynamics of rheology, and the fractional order of derivative represents the degree of time delay. Analyzing some laboratory experimental data of high temperature deformation of rocks and minerals such as halite, marble and orthopyroxene, we propose how to determine the orders of fractional derivative for viscoelastic behaviours of rocks and minerals. The order is related to the exponents for the temporal scaling in the relaxation modulus and the stress power-law of strain rate, i.e., the non-Newtonian flow law, and considered as an indicator representing the macroscopic behaviour and microscopic dynamics of rocks.