Miracle-dz/UniFAR-FTUs huggingface dataset:
Quantifying Climate Forcings and Feedbacks over the Last Millennium in the CMIP5–PMIP3 Models*

AbstractThe role of radiative forcings and climate feedbacks on global cooling over the last millennium is quantified in the CMIP5–PMIP3 transient climate model simulations. Changes in the global energy budget over the last millennium are decomposed into contributions from radiative forcings and climate feedbacks through the use of the approximate partial radiative perturbation method and radiative kernels. Global cooling occurs circa 1200–1850 CE in the multimodel ensemble mean with pronounced minima corresponding with volcanically active periods that are outside the range of natural variability. Analysis of the global energy budget during the last millennium indicates that Little Ice Age (LIA; 1600–1850 CE) cooling is largely driven by volcanic forcing (comprising an average of 65% of the total forcing among models), while contributions due to changes in land use (13%), greenhouse gas concentrations (12%), and insolation (10%) are substantially lower. The combination of these forcings directly contribut.
Effects of 15 years of conservation tillage on soil structure and productivity of wheat cultivation in northern China

An understanding of long-term tillage and straw management impact on soil structure and productivity is necessary for the further development of conservation tillage practice in dryland farming areas. Data from a 15-year field experiment conducted in Shanxi, on the loess plateau of northern China, were used to compare the long-term effects of no-till and residue cover (NTSC) with conventional tillage (CT) in a winter wheat (Triticum aestivum L.) monoculture. Long-term CT and straw removal resulted in poor soil structure and low productivity. Mean soil bulk density in NTSC was 1.5% less than in CT and capillary porosity ( 2 mm was much greater for NTSC in the 0–0.20 m profile. Soil organic matter and total N and P were 27.9%, 25.6%, and 4.4% greater in NTSC, respectively, and earthworms (19/m2) were found only in the no tillage treatment. Crop yield and water use efficiency tended to be higher under NTSC than under CT, especially in the years of low rainfall, suggesting that the change in soil structure has provided a better environment for crop development. Our 15-year experimental data indicate that NTSC is a more sustainable farming system, which can improve soil structure, and increase productivity with positive environmental impacts in the rainfed dryland farming areas of northern China.
Episodic modeling of the chemical structure of the troposphere as revealed during the spring MLOPEX 2 intensive

An episodic regional chemical transport model (CTM) is described and applied to modeling the vertical chemical structure of the troposphere, as revealed from aircraft flights in the vicinity of Hawaii during the springtime Mauna Loa Observatory Photochemistry Experiment 2c intensive. The CTM simulates the chemistry and transport of 50 species within the North Pacific basin. It is driven by output fields from the Pennsylvania State University/National Center for Atmospheric Research Mesoscale Modeling System. The modeled meteorology is highly correlated with European Centre for Medium-Range Weather Forecasts analyses on the large scale but is not accurate enough to correctly simulate the long-range transport of chemical plumes. The simulated total cloud cover is ap- proximately correct when compared with International Satellite Cloud Climatology Project cloud cover. However, the coverage of low-lying clouds is overpredicted, while the upper level cloudiness is underpredicted. Modeled and satellite-derived deep convection are reasonably correlated. The measured concentrations of H. O, CH3OOH, CO, NOv, and 03 are compared with simulated concentrtions from the marine boundary layer to approximately 9 krn. Although pronounced chem- ical plumes and vertical layering complicate the model-measurement comparison, modeled and measured concentrations are generally within a fact, or of 2. with particularly well simulated. A number of measured transient chemical events are examined. This study provides the necessary background for' subse(ltCnt papers examining the chemistry and transport of the Pacific basin in more detail.
Apéry's irrationality proof, mirror symmetry and Beukers's modular forms

In this paper, we will study the connections between Apery's proof of the irrationality of $\zeta(3)$ and the mirror symmetry of Calabi-Yau threefolds. From the mysterious sequences in Apery's proof, we will construct a fourth order Picard-Fuchs equation that has a large complex structure limit. The mirror map associated to it is the modular form with respect to $\Gamma_1(6)$ found by Beukers, while the instanton expansion of a rescaled Yukawa coupling give us another modular form found by Beukers. We will show how mirror symmetry provides further enlightening explanations to Beukers's and many others' enlightening explanations to Apery's mysterious proof.
Modelling dynamic stress changes caused by an extended rupture in an elastic stratified half-space

SUMMARY We model the time histories of coseismic stress changes produced by an earthquake rupture on an extended fault in a layered elastic half-space. We compute the stress perturbations caused by earthquakes using the discrete wavenumber and the reflectivity methods. We investigate the influence on the computed Coulomb stress changes of the adopted crustal velocity model, the rupture history and slip duration as well as the poro-elastic model assumed to calculate the pore-pressure changes. The comparison between the spatio-temporal evolution of the induced stress field, calculated for different crustal models and rupture histories, allows us to assess the depth and frequency dependence of the induced stress perturbation and the relative weight of dynamic and static stress changes. Our results show that the rise time and the rupture directivity are more important for characterizing the simulated stress time histories than the details of the rupture history. The adopted poro-elastic model affects the static stress changes more than the transient stress perturbations. The results of this study should be taken into account to model fault interaction through elastic stress transfer.
Axial summit trough of the East Pacific Rice 9°–10°N: Geological characteristics and evolution of the axial zone on fast spreading mid‐ocean ridge

The nature and morphological characteristics of axial summit troughs on fast (∼90–130 mm/yr−1 full spreading rate) and superfast spreading (>130 mm/yr−1) mid-ocean ridge crests reflect the time-integrated effects of long-term magmatic cycles, short-term volcanic episodicity, and the tensional stress regime imposed on young ocean crust. Two principal types of axial trough morphology have been identified and associated with distinct volcanic and tectonic processes occurring at fast and superfast spreading mid-ocean ridge crests. (1) Narrow axial troughs, ∼300–2000 m wide and ∼30–100 m deep) on the East Pacific Rise crest are classified as axial summit graben. The dimensions of axial summit graben, as well as the morphological and structural character of their walls and floors, suggest a primary tectonic origin. An axial summit graben may contain a nested axial summit collapse trough, implying that processes responsible for these endemic features may be linked. Near-bottom, side-looking sonar and observational data collected using the towed vehicle Argo I and submersible Alvin have been used to characterize the axial summit trough of the fast spreading East Pacific Rise between 9° and 10°N. A four-stage model is presented for the evolution of this axial summit collapse trough, as well as for other well-studied portions of the East Pacific Rise crest from 21°N to ∼20°S. We propose that the transition from a narrow, surface collapse-dominated axial trough to a broader, fault-bounded graben is controlled by the relative importance of diking, volcanism, hydrothermal cooling, and tectonism along a ridge segment over time periods <104 years.
PALEOCLIMATIC CHANGES IN DABUSU LAKE

Study on the carbonate content and oxygen isotope of a sediment section in Dabusu Lake revealed that this region has experienced several cold-wet and warm-dry climatic cycles since 15400 a BP. It was about 6740 a BP when the climate in the region reached a relatively stable warm stage, so that the lake water was gradually condensed and finally a saline lake was formed.
A global study of S-to-P and P-to-S conversions from the upper mantle transition zone

SUMMARY Long-period data of the Global Digital Seismograph Network (GDSN) recorded over the three-year period from 1984 to 1986 were studied for the occurrence of S-P and P-S conversions from the upper mantle transition zone that appear as precursors to teleseismic S arrivals. Conversions of this type were identified on a large number of single-station records. Simple stacking of many records enhanced the appearance of converted phases and demonstrated that no major lateral variations in the nature of the transition zone exist between various tectonic regions. S-P and P-S conversions from the 400 km discontinuity were best observed at distances between 70" and 85" while conversions from the 670 km discontinuity showed up best at distances beyond 87". The analysis of published source mechanisms and comparison with synthetic seismograms suggests that the appearance of converted phases is primarily governed by the earthquake radiation pattern. Phases that have undergone S-P conversions beneath the receiver are best observed from dip-slip events that radiate strong SV- and weak P-waves towards the station. P-S conversions beneath the source area, on the other hand, are frequently observed from events that radiate strong P and little SV energy towards the station, and also from some strike-slip events. Comparison of observed with synthetic seismograms suggests that the PREM model of Dziewonski & Anderson (1981) explains most of the observations. Observed S-P and P-S conversions from the 670 km discontinuity, however, often have larger amplitudes than in the synthetics. Constructive interference of converted waves with the P-wave coda, source radiation effects and a velocity contrast across the 670 km discontinuity which is higher than in PREM may all contribute to the discrepancy.
Evolution and Mass Accumulation of the Cenozoic Hoh Xil Basin, Northern Tibet

ABSTRACT This work reconstructs the depositional history and estimates the mass of sediments stored in the Hoh Xil basin, northern Tibet, the largest Cenozoic sedimentary basin in the hinterland of the Tibetan Plateau. The mass estimate is derived from over 75 geologic sites and 21 measured stratigraphic sections, with a total thickness of 13,478 m. The results show that the Hoh Xil basin underwent six stages of development from the Early Eocene to the Early Miocene, with a hiatus in sedimentation in the Late Oligocene. The Fenghuoshan Group was deposited during the first four stages 56.0-52.0, 52.0-43.0, 43.0-38.2, and 38.2-31.5 Myr; the Yaxicuo Group comprises stage 5, 31.5-30.0 Myr; the Wudaoliang Group covered the entire basin during the last stage, 23.0 to 16.0 Myr. The strata of the Fenghuoshan and Yaxicuo groups were strongly deformed, mainly during the Late Oligocene, whereas only minor tilting has occurred since then in the Wudaoliang Group. The depositional history indicates that the Hoh Xil basin could have been formed as a piggyback basin and that the onset of northeastward growth of the central Tibet was from the Early Eocene (about 56 Myr) to the Late Oligocene. The analyses of subsidence history and mass accumulation indicate that both accelerated subsidence and sudden increases of accumulation rate occurred at the four periods of about 52.0, 40.5, 34.5, and 31.5 Myr in three sub-basins and over the entire basin from the Early Eocene to the Early Oligocene. During the four periods, the deposits were either lacustrine turbidite sandstone or fan-delta conglomerate, which resulted from the tectonic movement. On the basis of the mechanism of northeastward growth of the piggyback basins and the consistency of accelerated subsidence, depositional systems, and mass accumulation, we suggest the continental collision and early uplift of the Tibetan Plateau controlled the formation and evolution of the Hoh Xil basin. The event that occurred at 52.0 Myr could represent the continental collision between India and Asia, whereas the other three events that happened during about 40-30 Myr could show the early uplift of the Tibetan Plateau. This study on sedimentary records in the Hoh Xil basin, along with widespread magmatic activity in eastern and western Tibet, suggests a diachronous uplift history for the Tibetan Plateau from east to west.
Innovative Methods for Characterizing Chlorinated Volatile Organic Compounds in the Vadose Zone

Chlorinated solvents, such as tetrachloroethene (PCE), trichloroethene (TCE), and carbon tetrachloride (CT), are primary contaminants of concern for a vast majority of federal and state Superfund sites in the US due to their prior widespread use as solvents for numerous industrial and commercial applications. Source-zones containing large quantities of contaminant are typically present at sites contaminated by chlorinated solvents. Particularly in regions such as the SW US, these source zones reside, at least in part, in the extensive vadose zones typical of these regions. There are two primary concerns associated with sites that contain vadose-zone contaminant sources. First, discharge of contaminant vapor from the vadose-zone source may impact the underlying groundwater. This could contribute to overall risk posed by the site, and delay attainment of groundwater cleanup goals. Second, contaminant vapor from the vadose-zone source may migrate to the land surface and transfer into buildings, thereby causing vapor intrusion. The focus of this research is the development and application of innovative methods for characterizing vadose-zone contamination. Phytoscreening is a new, rapid, and relatively low-cost characterization technology that can be used to screen an area for the presence of select contaminants such as chlorinated VOCs. Phytoscreening is based on the sampling and analysis of plant tissues (branch, trunk, leaf, seed, needle) to detect the presence of contamination in soil and groundwater. Phytoscreening is applied to three sites in Arizona to evaluate its use in semi-arid environments. In addition, all available field data sets have been compiled to examine potential correlations between contaminant concentrations measured for tree tissue and those for groundwater. Contaminant concentrations were detected in tree tissue samples collected from two of the three Arizona sites. A review of the field site data suggests that a correlation exists between PCE and TCE concentrations measured for tree tissue and those measured in groundwater. The correlation can be used to estimate vegetation concentrations when groundwater concentrations are known. The reasonable degree of correlation supports the use of phytoscreening as a robust screening tool to provide a first-order characterization of anticipated concentrations of contaminants in groundwater. This tool can also be used to screen an area for vapor intrusion potential. A sampling method for the determination of chlorinated contaminant vapor concentrations present in the vadose zone, specifically trichloroethene (TCE), has been developed, and was applied at the Tucson International Airport Authority (TIAA) Superfund site. The method was modified from the NIOSH Manual of Analytical Methods (NMAM) 1022 for TCE, and is targeted to situations requiring cost effective sample collection, particularly for cases when concentrations are at or below maximum contaminant levels (MCLs). In the modified NIOSH method, TCE vapor is sampled using a solid sorbent cartridge…
Heavy metals in green vegetables and soils from vegetable gardens in Dar es Salaam, Tanzania.

Edible portions of five varieties of green vegetables, namely amaranth, chinese cabbage, cowpea leaves, leafy cabbage and pumpkin leaves, collected from several areas in Dar es Salaam, were analyzed for lead, cadmium, chromium, zinc, nickel and copper. Except for zinc, the levels of heavy metals in the vegetables grown at Tabata area were much higher than in the vegetables from Ukonga and Kiwalani. Amaranth and pumpkin leaves had more than 60% higher content of heavy metals, especially copper, chromium and lead, than the other vegetables. All vegetables from Tabata, Buguruni and Sinza had lead-levels higher then the FAO/WHO recommended permissible levels in foods. Amaranth, leafy and chinese cabbages had high zinc content. Zinc levels in chinese cabbage and leafy cabbage from Kiwalani, Sinza and Ukonga areas were higher than the permissible FAO levels in foods. The soils from Tabata and Sinza areas had high levels of lead, chromium, zinc and copper while the soils from Kiwalani, Makongo and Ukonga areas had high levels of zinc and copper. There was a direct positive correlation between the zinc and lead levels in soils with the levels in vegetables. Such relation was absent for the other heavy metals. Considering an average daily intake of only 202g of fresh vegetables per person per day, all the vegetables grown at Tabata and Buguruni had lead concentration which would be a health hazard for human consumption. Tanzania Journal of Science Volume 27 (2001), pp. 37-48
Signatures of Mixing from the Bermuda Slope, the Sargasso Sea and the Gulf Stream

Abstract Nearly simultaneous profiles of temperature microstructure and velocity shear were made adjacent to the island of Bermuda. Profiles with elevated microstructure levels were found in close association with regions of pronounced steplike finestructure, which contained nearly adiabatic regions from 2 to 10 m thick. The temperature spectra and the presence of numerous centimeter-scale temperature inversions gave evidence that active turbulent mixing was occurring in some of these regions. These were the locations in which large-scale surveys, reported by Hogg et al. (1978), found that eddies impinging on the island were forcing alongshore flow. Although the mixing was intense by comparison with profiles in the thermocline, the limited geographical extent of the affected areas and the moderate levels indicate that mixing adjacent to islands is of minor importance on a global basis. A very limited number of profiles taken in the Sargasso Sea found microstructure levels in the thermocline that were simi.
Near-Infrared Spectroscopy to Estimate the Maximum Temperatures Reached on Burned Soils

We studied the use of near-infrared (NIR) reflectance spectroscopy as a potential method to estimate a posteriori the maximum temperatures reached (MTR) on burned soils. When soils are heated, the NIR spectra change in accordance with the MTR. Thus, after calibrating, these patterns of NIR could be used as a fingerprint to estimate the MTR in burned soils. Successful validations of the models relating NIR spectra with MTR were obtained in each of the five soils studied (local models), with r 2 values ranging from 97.47 to 98.56%. A global model constructed with samples from the five soils studied obtained a similar accuracy, suggesting the presence in soils of some NIR-detectable compounds with similar thermal sensitivity. The influence of the variability caused by the soil type and the duration of heating during model constructions is also evaluated and discussed. The use of NIR presents interesting advantages, such as low cost, low time consumption, minimal pretreatment of samples, no need for chemicals, and accuracy. The results indicate that the MTR could be estimated in burned soils with NIR, offering a new perspective on studies of wildfire effects on soils.
A subsurface cyclonic eddy in the Bay of Bengal

CTD data collected from the northwestern Bay of Bengal during late July 1984 reveal the existence of a cold core subsurface eddy centered at 17°40'N and 85°19'E. The thermal structure observed across the eddy indicates that it was confined to a level well below the mixed layer, between 50 and 300 db, and that it had a diameter of about 200 Ian. A temperature drop of 4-5°C as compared with the surroundings was observed at the center of the eddy. A plausible mechanism for the eddy generation is baroclinic instability at the interface of two opposing boundary currents present along the shelf edge of the western boundary of the Bay of Bengal. The southward current in the northern bay results partly from fresh water influx and to a larger extent from the action of wind stress curl while in the southern part the northward current is purely wind-driven. High stratification caused by fresh water influx prevented the eddy from being detected at the surface.
The meteorological data of William Hutchinson and a Liverpool air pressure time series spanning 1768–1999

This paper discusses some of the meteorological measurements made at Liverpool by Captain William Hutchinson in the second half of the eighteenth century. It gives an overview of the various data sets, most of which are now in computer‐accessible form, and provides assessments of their quality, the aim being to gain an overall impression of how good an observer Hutchinson was. His air pressure data have been studied in detail, through comparisons with information from other UK stations, and via investigation of the sea‐level response to air pressure changes as observed in his tidal measurements. A first attempt has been made to construct a Liverpool air pressure time series spanning 1768–1999, by means of the combination of Hutchinson's data with later information from the Liverpool docks and Bidston Observatory. Copyright © 2006 Royal Meteorological Society
Search for a glacial‐age 14C‐depleted ocean reservoir

Measurements of the radiocarbon age difference between mixed benthic foraminifera and several coexisting planktic entities were made in hopes of finding evidence for the existence of an isolated glacial‐age abyssal ocean reservoir whose demise would explain the large drops in the 14C to C ratio in atmosphere and surface ocean carbon which occurred during the period of deglaciation. Forty‐six new radiocarbon results were obtained at seven depths covering the full range of glacial time (i.e., ∼27 to 15 14C kyrs) from an equatorial Pacific sediment core at 4.4‐km water depth. Even though age reversals for foraminifera (but not for coccoliths) at two of the eight depths and large age differences between G. sacculifer and three submixed‐layer planktic species mar this data set, there remains little likelihood that such a reservoir existed.
Soils and Soil Fertility

Preface.1 Soil.2 Soil Formation.3 Physical Properties of Soils.4 Soil Mechanics.5 Soil Water.6 Soil Organic Matter.7 Soil Mineralogy.8 Soil Chemistry.9 Amending the Soil.10 Fertilizers.11 Nitrogen.12 Phosphorus.13 Potassium.14 Calcium, Magnesium, and Sulfur.15. The Micronutrients.16. Variations in Plant Composition.17 Soil Classification and Survey.18 Land Use and Soil Management.19 Water Management.20 Soil Erosion and Its Control.21 Soil Pollution.Appendix.