Miracle-dz/UniFAR-FTUs huggingface dataset:
Applications of RS, GPS and GIS to Forest Management in China

遥感(RS ) 的应用程序，全球放系统(GPS ) ，地理信息系统(GIS ) 和三的联合在森林管理的技术被介绍。 它显示那，与快速计算机技术的改进，三系统将成为林地管理系统的很重要的部分。
Distribution of hopanoids along a land to sea transect: Implications for microbial ecology and the use of hopanoids in environmental studies

Bacteriohopanepolyols (BHPs) are lipid constituents of diverse bacteria and have great potential as taxonomically and environmentally diagnostic biomarkers. In order to examine their environmental behavior and potential for tracing biogeochemical processes, we analyzed BHPs and geohopanoids (the diagenetic products of BHPs) in soils and surface sediments from the middle Yangtze River catchment to the East China Sea (ECS) shelf. These data are compared to an up‐to‐date survey of BHP distributions in soils, including regions collectively covering the Arctic, temperate, subtropics, and tropics. Regional climatic differences, particularly temperature, likely exert an important control on BHP distributions in soils. In the aquatic (river–estuary–shelf) setting, BHP concentrations and structural diversity are substantially lower than in soils, suggesting that in aquatic environments either bacterial biodiversity is lower or there is not the same requirement for hopanoid synthesis. However, different aquatic regimes vary substantially: high BHP diversity and enhanced BHP production occur in the biogeochemically dynamic Yangtze estuary, whereas BHP distribution is uniform with much less structural diversity in the oligotrophic ECS open shelf. The Rsoil index, based on the relative abundances of soil‐marker BHPs against bacteriohopanetetrol, is suggested as a new approach to trace soil organic matter input into marine sediments. The Rsoil indices decrease from the river to the ECS, correlating strongly with branched and isoprenoid tetraether indices and moderately correlating with δ13C of organic carbon values and the concentrations of higher plant biomarkers, demonstrating their ability to trace soil organic matter inputs at least to the ECS.
Pacific CaCO3 Preservation and δ18O Since 4 Ma: Paleoceanic and Paleoclimatic Implications

The Pliocene-Pleistocene history of CaCO3 preservation in the central equatorial Pacific is reconstructed from a suite of deep-sea cores and is compared to fluctuations in global ice volume inferred from δ18O records. The results are highlighted by: (1) a strong covariation between CaCO3 preservation and ice volume over 104 to 106 year time scales; (2) a long-term increase in ice volume and CaCO3 preservation since 3.9 Ma demonstrated by a deepening of the lysocline and the carbonate critical depth; (3) a dramatic shift to greater CaCO3 preservation at 2.9 Ma; (4) distinctive ice-volume growth and CaCO3 preservation events at 2.4 Ma, which are associated with the significant intensification of northern hemisphere glaciation; (5) a mid-Pleistocene transition to 100-kyr cyclicity in both CaCO3 preservation and ice volume; and (6) a 600-kyr Brunhes dissolution cycle superimposed on the late Pleistocene glacial/interglacial 100-kyr cycles. CaCO3 preservation primarily reflects the carbonate chemistry of abyssal waters and is controlled by long-term (106 year) and short-term (104 to 105 year) biogeochemical cycling and by distinct paleoclimatic events. We attribute the long-term increase in CaCO3 preservation primarily to a fractionation of CaCO3 deposition from continental shelf to ocean basin, and secondarily to a gradual rise in the riverine and glaciofluvial flux of Ca++. On shorter time scales, the fluctuations in CaCO3 preservation slightly lag ice volume fluctuations and are attributed to climatically induced changes in the circulation and chemistry of Pacific deep water.
Desert Flower: The Extraordinary Journey of a Desert Nomad

Waris Dirie (the name means desert flower) lives a double life - by day she is a famous model and UN spokeswoman on women's rights in Africa, at night she dreams of her native Somalia. Waris, one of 12 children, was born into a traditional family of desert nomads in East Africa. She remembers her early childhood as carefree- racing camels and moving on with her family to the next grazing spot - until it came her turn to meet the old woman who administered the ancient custom imposed on most Somalian girls: circumcision. Waris suffered this torture when she was just five years old. Then, aged 12, when her father attempted to arrange a marriage with a 60 year old stranger in exchange for five camels - she took flight. After an extraordinary escape through the dangerous desert she made her way to London and worked as a maid for the Somalian ambassador until that family returned home. Penniless and speaking little English, she became a janitor in McDonalds where she was famously discovered by a fashion photographer. Her story is a truly inspirational and extraordinary self-portrait of a remarkable woman whose spirit is as breathtaking as her beauty.
Visualizing Geographic Classifications Using Color

Abstract This paper presents the cartographic elements of a system for classifying and visualizing high-dimensional geographic datasets. The system has been developed as part of the Land Ocean Interactions in the Coastal Zone (LOICZ) project. The goal of the system is to develop regional and global typologies of coastal zones using large multi-variable datasets. Our implementation bring together statistical clustering algorithms with visualization capabilities to allow easy analysis and comprehension of the result. The two main tasks of the visualization are to allow for discrimination of multiple classes and to show relationships between those classes. These are accomplished in two different visual presentations. In both cases, the system selects colors appropriate to the purpose. In the latter case — showing relationships — the system uses a novel iterative refinement algorithm to select the colors. The result show that the system is successful at both generation the classes and visualizing the relationships between them.
The effect of water vapour on the normalized difference vegetation index derived for the Sahelian region from NOAA AVHRR data

Abstract The near-infrared channel of the NOAA advanced very high resolution radiometer (AVHRR) contains a water vapour absorption band that affects the determination of the normalized difference vegetation index (NDVI). Daily and seasonal variations in atmospheric water vapour within the Sahel are shown to affect the use of the NDVI for the estimation of primary production. This water vapour effect is quantified for the Sahel by radiative transfer modelling and empirically using observations made in Mali in 1986. In extreme cases, changes in water vapour are shown to result in a reduction of the NDVI by 0.1. Variations of the NDVI of 001 would result from typical low atmospheric water vapour days within the wet season. If these conditions were to persist throughout the season it would lead to an overestimate of production of 200 kg ha−1. The measurement of atmospheric water vapour using the AVHRR thermal channels, the high-resolution Infrared Sounder 2 (HIRS2), and the microwave sounding unit (MSU) senso.
In situ pressure–temperature conditions of a tectonic mélange: Constraints from fluid inclusion analysis of syn‐mélange veins

Abstract Pressure and temperature (P–T) conditions of mélange formation are estimated from fluid inclusions within “syn‐mélange” veins developed in the necks of boudins of sandstone blocks in the mélange of the Shimanto accretionary complex, south‐west Japan. The mélange records décollement‐zone processes. P–T conditions are in the range of 81 (+15) to 235 (±18) MPa and 150 (±25) to 220 (±31)°C. Assuming a constant fluid‐pressure to lithostatic‐pressure ratio for each data set, we estimate a P–T gradient of between 10.0°C/km (+0.2/−1.5) (lithostatic pressure) and 4.2°C/km (+0.1/−0.9) (hydrostatic pressure) from these results. The estimated lithostatic P–T gradient is much lower than that calculated from the age of the subducting oceanic plate. The estimated P–T conditions suggest that the mélange was formed within the seismogenic zone (hypothesized from thermal modeling), although the deformation mechanism of mélange (i.e. dominant diffusive mass transfer mainly in shale matrix with minor brittle breakage mainly in sandstone blocks) does not show evidence of seismic deformation. In addition, at the time of syn‐mélange vein formation, a shale matrix of mélange has injected into the vein, which indicates a ductile deformation of shale. A possible explanation for this discrepancy is that the mélange was formed during the interseismic period.
Sampling strategies for the comparison of climate model calculated and satellite observed brightness temperatures

Brightness temperatures derived from polar-orbiting satellites are valuable for the evaluation of global climate models. However, the effect of orbital constraints must be taken into account to ensure valid comparisons. As part of the Atmospheric Model Intercomparison Project II climate model comparisons, this study seeks to evaluate the monthly mean simulated brightness temperature differences of possible model output sampling strategies with respect to the exact satellite sampling and whether they can be practically implemented to provide meaningful comparisons with these satellite observations. We compare various sampling strategies with a proxy satellite data set constructed from model output and actual TIROS operational vertical sounder orbital trajectories, rather than with the observations themselves. To a large extent, this enables isolation of the sampling error from errors caused by deficiencies in the modeled climate processes. Our results suggest that the traditional method of calculating brightness temperatures from monthly mean temperature and moisture profiles yields biases from both nonlinear effects and the removal of the diurnal cycle that may be unacceptable in many applications. However, we also find that a brightness temperature calculation every hour of the simulation provides substantially lower sampling biases provided that there are two or more properly aligned satellites. This is encouraging because it means that for many applications modelers need not accurately mimic actual satellite trajectories in the sampling of their simulations. If only one satellite is available for comparison with simulations, more sophisticated sampling seems necessary. For such circumstances, we introduce a simple procedure that serves as a useful approximation to the rather complex procedure required to sample a model exactly as a polar-orbiting satellite does the Earth. With all sampling methods, removal of biases associated with cloud cover is problematic and deserves further study.
Relationship between LiDAR-derived forest canopy height and Landsat images

The mean and standard deviation (SD) of light detection and ranging (LiDAR)-derived canopy height are related to forest structure. However, LiDAR data typically cover a limited area and have a high economic cost compared with satellite optical imagery. Optical images may be required to extrapolate LiDAR height measurements across a broad landscape. Different spectral indices were obtained from three Landsat scenes. The mean, median, SD and coefficient of variation (CV) of LiDAR canopy height measurements were calculated in 30-m square blocks corresponding with Landsat Enhanced Thematic Mapper Plus (ETM+) pixels. Correlation and forward stepwise regression analysis was applied to these data sets. Mean and median LiDAR height versus normalized difference vegetation index (NDVI), normalized difference moisture index (NDMI), normalized burn ratio (NBR) and wetness Tasseled Cap showed the best correlation coefficients (R 2 ranging between −0.62 and −0.76). Nineteen regression models were obtained (R 2 = 0.65–0.70). These results show that LiDAR-derived canopy height may be associated with Landsat spectral indices. This approach is of interest in sustainable forest management, although further research is required to improve accuracy.
Observations on the vertical structure of tidal and inertial currents in the central North Sea

Tidal and inertial current ellipses, measured at several locations and depths in the central North Sea during a number of monthly periods in 1980, 1981 and 1982, are decomposed into counterrotating, circular components to which Ekman dynamics are applied to determine Ekman layer depths and vertical phase differences, from which are inferred overall values of the eddy viscosity and drag coefficient. Stratification effects produce an additional vertical phase shift of the anticyclonic rotary component, indicative of an inverse proportionality of the eddy viscosity to the vertical density gradient. From the time variations of the Ekman layer depths of the semidiurnal tidal components, as well as from the vertical structure of the inertial current component, we infer variations in the relative vorticity of the low-frequency flow
Impact of air‐sea interaction on East Asian summer monsoon climate in WRF

[1] This study investigates the effects of air-sea interaction on the simulated East Asian summer monsoon (EASM) climate in a regional climate model. An ocean mixed layer model with a revised surface roughness length formulation that was originally designed for tropical cyclone simulation and a prognostic sea surface skin temperature scheme that considers the heat budget at the water surface are systematically evaluated on the monsoonal climate over East Asia for July 2006 in the regional Weather Research and Forecasting (WRF) model. Also, 9-year (2000–2008) June–August simulations are performed to evaluate the overall impacts of these three components on the simulated EASM climatology. The 1 month simulation for July 2006 reveals that the inclusion of the ocean mixed layer model cools the water surface due to enhanced mixing, in particular, when winds are strong. Such cooling is largely compensated by the inclusion of prognostic skin temperature since solar heating in daytime overwhelms the cooling in nighttime. The revised surface roughness length effectively reduces the surface heat flux by reducing the exchange coefficients, against the conventional Charnock formula. Consideration of the three components together results in the reduction of systemic biases of excessive precipitation and weakening of the North Pacific high in the summer climate from 2000 to 2008. It is concluded that the methodology designed in this study can be an efficient way to represent the air-sea interaction in regional atmospheric models for numerical weather prediction and climate simulation.
Simulation of oil expulsion by 1-D and 2-D basin modelling — saturation threshold and relative permeabilities of source rocks

Abstract In order for oil to accumulate in economic quantities, it first has to be generated and expelled from source rocks in sufficient quantities. In spite of long term efforts, the mechanism of oil expulsion from the source rocks is not completely understood. For modelling expulsion, the adoption of pressure-driven multiple-phase fluid flow governed by Darcy’s law is widely accepted. However, relative permeabilities for fine-grained source rocks, which is an essential parameter for this model, are very difficult to specify. The conventional reservoir-rock curve is obliged to be used for the modelling. Simplification of the relative permeability model is generally used for one-dimensional basin modelling. The 1-D model also requires substantial optimization of the key parameter, saturation threshold. Laboratory measurement of relative permeabilities for fine-grained rocks is very difficult, therefore, we carefully interpreted the analysed laboratory data on various sandstones to establish a relationship between relative permeability curves and pore geometry parameters, with a view to extrapolate the relationships developed in sandstones to fine-grained source rocks. It was found that the relative permeability curves, or irreducible water saturation are controlled by two factors ; grain size and clay content. Since the total surface area of the pore system becomes greater as the grain size decreases, we consider surface water adsorbed on the grain surface as a part of irreducible water. Since clay contains micro-porosity which cannot be displaced by oil due to high capillary pressure, we regard this to also play a role. Prediction of relative permeability curves for fine-grained rocks by both processes results in the curve with high irreducible water saturation. The new relative permeability curves were tested by both one-dimensional and two-dimensional basin modelling. Test results indicate that the new curves can reproduce expulsion efficiency, locations of accumulations and leaking through cap rock, which is consistent with actual observations.
Principles of Early Development of Karst Conduits Under Natural and Man-Made Conditions Revealed by Mathematical Analysis of Numerical Models

Numerical models of the enlargement of primary fissures in limestone by calcite aggressive water show a complex behavior. If the lengths of the fractures are large and hydraulic heads are low, as is the case in nature, dissolution rates at the exit of the channel determine its development by causing a slow increase of water flow, which after a long gestation time by positive feedback accelerates dramatically within a short time span. Mathematical analysis of simplified approximations yields an analytical expression for the breakthrough time, when this happens, in excellent agreement with the results of a numerical model. This expression quantifies the geometrical, hydraulic, and chemical parameters determining such karst processes. If the lengths of the enlarging channels are small, but hydraulic heads are high, as is the case for artificial hydraulic structures such as dams, it is the widening at the entrance of the flow path which determines the enlargement of the conduit. Within the lifetime of the dam this can cause serious water losses. This can also be explained by mathematical analysis of simplified approximations which yield an analytical threshold condition from which the safety of a dam can be judged. Thus in both cases the dynamic processes of karstification are revealed to gain a deeper understanding of the early development of karst systems. As a further important result, one finds that minimum conditions, below which karstification cannot develop, do not exist.
ENSO Forced Changes in Precipitation Distributions and Related Global Circulation Patterns : Gulf of Mexico Region

The El Nino Southern Oscillation (ENSO) forced precipitation is well documented in several regions around the world. Mid-latitude atmospheric circulations contribution towards extreme precipitation during ENSO is less well understood. One area that has a strong ENSO signal in extratropical and tropical storminess is the Gulf of Mexico. This region is influenced by high SSTs the subtropical jet and even polar intrusions. The objective of this research is to improve understanding of the link between ENSO extreme precipitation and the role of regional atmospheric circulations. The probability density function cumulative density function Kolmogorov-Smirnov (KS) test and a hotspot analysis are employed to explore the independent and spatial statistics of precipitation distributions between phases of ENSO across the Gulf of Mexico region. The months of August through January are examined but October and December display significant spatial patterns and are selected for a synoptic analysis of six grid boxes to represent five regions of large scale ENSO forcing. Our primary finding indicates subtropical jet stream winds are significantly different and stronger during El Nino especially for the month of October. This would suggest that El Nino would lead to more extremes throughout the Gulf of Mexico which is not the case from the spatial autocorrelation analysis. Thus other synoptic scale forcings must be at work. Differences in the cumulative distribution function (CDF) at lower rain rates seem to be more related to the strength and position of the polar jet and may be influenced by jet-interactions. Extreme precipitation during La Nina was traced to a weaker polar jet and the subtropical jet positioned away from the region of interest.
The utility of surface temperature measurements for the remote sensing of surface soil water status

Experiments carried out on an Avondale loam soil indicated that the thermal inertia concept of soil water content detection is reasonably sound. The volumetric water contents of surface soil layers between 2 and 4 cm thick were found to be linear functions of the amplitude of the diurnal surface soil temperature wave for clear day-night periods. They were also found to be linear functions of the daily maximum value of the surface soil-air temperature differential. Tests on three additional soils ranging from sandy loam to clay indicated that the relations determined for Avondale loam could not be accurately applied to these other soil types. When the moisture characteristic curves of each soil were used to transform water contents into pressure potentials, however, it was found that soil water pressure potential could be determined without prior knowledge of soil type, and thus its value as a potential soil water status survey tool was significantly enhanced.
Atmospheric and Oceanic Observations from the POSEIDON Buoy Network: Initial Results

A preliminary analysis of atmospheric and surface oceanic observations from the POSEIDON buoy network is presented. The data set consists of concurrent observations of physical properties at the atmosphere-ocean boundary layers as well as chlorophyll- f (chl- f ) and dissolved oxygen content of the subsurface layer. The quality of data is evaluated using standard procedures and comparison to reference measurements with special focus on bio-fouling effects. The extended temporal and spatial coverage of the observations provides, for the first time in the Aegean Sea, the opportunity to study synoptic and mesoscale variability in the upper oceanic layer and its response to atmospheric forcing. Furthermore, examples of high frequency variability of physical and biochemical processes in the mixed layer and the seasonal pycnocline are given.
Estimates of acidification of lakes in the Mt. Zirkel Wilderness Area, Colorado

Seventy lakes in the Mt. Zirkel Wilderness Area, Colorado, were sampled for alkalinity, and 20 of these lakes were sampled for major anions. Analysis of the data indicates that most of the lakes are extremely sensitive to acidification; about half of the lakes have alkalinities less than 100 . mu.eq/L. A linear regression of alkalinity against lake altitude accounts for 55% of the variance in alkalinity among the lakes, whereas a regression of alkalinity against dominant geologic unit (exclusive of altitude) accounts for 63% of the alkalinity variance. A conceptual model of lake acidification allows estimation of the quantity of acidification that may have occurred. Acidity associated with strong acid anions probably neutralized no more than 9 . mu.eg/L of alkalinity. This estimate is much smaller than a previous estimate for nearby Colorado lakes.