Miracle-dz/UniFAR-FTUs huggingface dataset:
Projected changes in east african rainy seasons

AbstractA regional climate model with 90-km horizontal resolution on a large domain is used to predict and analyze precipitation changes over East Africa caused by greenhouse gas increases. A pair of six-member ensembles is used: one representing the late twentieth century and another the mid-twenty-first century under a midline emissions scenario. The twentieth-century simulation uses boundary conditions from reanalysis climatology, and these are modified for the mid-twenty-first-century simulation using output from coupled GCMs. The twentieth-century simulation reproduces the observed climate well. In eastern Ethiopia and Somalia, the boreal spring rains that begin in May are cut short in the mid-twenty-first-century simulation. The cause is an anomalous dry, anticyclonic flow that develops over the Arabian Peninsula and the northern Arabian Sea as mass shifts eastward near 20°N in response to strong warming over the Sahara. In Tanzania and southern Kenya, the boreal spring's long rains are reduced thro.
Phytoremediation Potential of Shallots (Allium ascalonicum L.) in Iron-Contaminated Mudflow Sites: A Case Study from Lapindo, Indonesia

This research investigates the potential of shallots (Allium ascalonicum L.) for phytoremediation in land areas contaminated with high levels of iron (Fe) metal due to the 2006 Lapindo mudflow in Indonesia. The study was conducted in the Jetis Village, Sidoarjo District, from December 2021 to February 2022, employing the Randomized Complete Block Design (RAK) method. The methodology involved the addition of different concentrations of Lapindo mud (0% as control, 10%, 20%, and 30%) to the planting medium. Our findings reveal a significant relationship between the concentration of Lapindo mud and several plant metrics, such as plant height, leaf count, and wet and dry weight, all of which were assessed using regression and correlation analysis. Additionally, we observed that a 30% concentration of the mud led to physical stunting in the shallot plants, implying that excessive absorption of heavy metals can inhibit growth. Notably, in the 30% mud concentration scenario, the Fe content was reduced from an initial 11.82% to 4.52% post-planting. The study thus confirms the capacity of shallots to perform phytoremediation, specifically by decreasing Fe content, thereby offering a potential sustainable solution to manage metal-contaminated sites resulting from geological disasters.
On the dynamics of the secondary eyewall genesis in Hurricane Wilma (2005)

The Weather Research and Forecast model is used to simulate the secondary eyewall genesis (SEG) and evolution in Hurricane Wilma (2005). The structure and time evolution of the secondary eyewall are well captured. The theory of empirical normal modes is then applied to study the SEG. For azimuthal wavenumber 1 anomalies, the wave activity spectra indicate that the leading modes (1 and 2), are vortex Rossby waves (VRWs). The Eliassen‐Palm (EP) theorem is used to diagnose the impact of the propagating waves on the formation of the secondary eyewall. Analysis of the EP flux and its time‐mean divergence show that in the lower troposphere the VRWs propagate outward outside the primary eyewall. The fact that the critical radius of the leading modes is located close to the region where the secondary eyewall eventually develops suggests that VRWs play an important role in SEG.
The relationship between clouds and dynamics in Southern Hemisphere extratropical cyclones in the real world and a climate model

The representation of clouds over the Southern Ocean in contemporary climate models remains a major challenge. A major dynamical influence on the structure of clouds is the passage of extratropical cyclones. They exert significant dynamical influences on the clouds in the dynamically active frontal regions as well as in the dynamically suppressed regions ahead and behind the cyclones. A cyclone compositing methodology is applied to a reanalysis and vertical profiles of cloudiness from CloudSat/CALIPSO to quantify the relationship between clouds and dynamics in extratropical cyclones over the Southern Ocean. It is found that the range of cloud fraction, vertical motion, and relative humidity changes considerably with height. There is a strong quasi‐linear relationship between the three variables which changes with altitude. After establishing the observed relationships, the methodology is applied to the Australian Community Climate and Earth System Simulator to evaluate the model's ability to simulate the identified cloud‐dynamics relationships. While the model is able to qualitatively reproduce the overall cloud structure, the circulation around the cyclone is generally too weak. As a result, the model fails to represent the observed cloud to dynamics relationship. This wrong relationship in the model leads to a misrepresentation of the cloud field manifested as either an error in the cloud fraction or as simulating the “right” clouds for the “wrong” reason. The result underscores the importance of relationship‐oriented model evaluation techniques over simple right or wrong assessments.
Ice particles and electron “bite‐outs” at the summer polar mesopause

Rocket measurements of electron density profiles in the vicinity of the high-latitude summer mesopause have frequently shown the existence of a sharply bounded layer of thickness ∼1 km in which the electron density is depleted by as much as an order of magnitude below the value that would be inferred from the densities above and below. The most plausible explanation of these “bite-outs” is that they are caused by scavenging of the electrons by small ice particles that exist in the cold environment of the polar summer mesopause and that are related to those responsible for noctilucent and polar mesospheric clouds. This possibility is explored quantitatively using a simplified version of relations developed earlier (Natanson, 1960) to describe the charging of aerosols. It is shown that the radius of the ice particles must be of the order of 10 nm in order to satisfy the number density requirement and at the same time keep the water content within reasonable bounds. These particles would be too small to produce a visible cloud but may form a semipermanent substrate from which the larger cloud particles can develop under suitable conditions.
A method of land use/land cover change detection from remote sensing image based on support vector machines

Land cover/land use has become one of the crucial but basic tasks in carrying out a series of important work. With the development of remote sensing techniques and Geo analysis model, using remotely sensed data to monitor the status and dynamical change of land cover/land use has become one of the most rapid, credible and effectual approaches. To improve the accuracy of change detection from remote sensing image, this paper introduces a new method of change detection from remote sensing image based on support vector machine (SVM), using multi-spectral remote sensing data. We choose Hengshui city in China as a typical studying sample. The result shows that it is competitive with other recently developed methods for change detection when applied to the same data sets and yield good performance with very limited training data.
Availability, volatility, stability, and teleconnectivity changes in prairie water supply from Canadian Rocky Mountain sources over the last millennium

Multidecadal variability can have profound implications for long‐term viability of existing water management practices and design of water conveyance, storage, and treatment infrastructure. However, baseline hydrology for water supply planning and engineering design rarely includes the full range of variability and extremes captured by proxies and models of pre‐ and postinstrumental climate and hydrology. This paper examines the paleohydrology of the Saskatchewan River Basin (SRB), where Canada's fastest growing economy and population are vulnerable to drought and heavily reliant on runoff from the Rocky Mountains. We take a novel approach to time‐series analysis of tree‐ring reconstructions of the North and South Saskatchewan Rivers. This study evaluates shifts in water availability, volatility as defined in terms of statistical dispersion, and stability as defined in terms of Shannon entropy, between adjacent 30 year windows—corresponding to the standard climatic normal period, and human generational timescales. Broadly speaking, outcomes reveal that gauge records appear unreliable as a basis for long‐term water supply planning and engineering design. For example, (1) two preinstrumental periods of stable water deficits represent sustained droughts that current water use and management could not endure, (2) hydroclimatic relationships between the two subbasins, and with the Pacific Decadal Oscillation, change over the generations, and (3) the most anomalous period of the past millennium, with coinciding high levels of availability, volatility, and stability, was about 1890–1920. This happens precisely when the SRB was transformed from prairie and parkland to agricultural land cover—and the precedents for water allocation and use were established.
Biogenic volatile organic compound emissions in central Africa during the Experiment for the Regional Sources and Sinks of Oxidants (EXPRESSO) biomass burning season

The recent aircraft and ground-based Experiment for the Regional Sources and Sinks of Oxidants (EXPRESSO) campaign in central Africa studied atmospheric trace gases and aerosols during the biomass burning season. Isoprene, emitted from vegetation, was the most abundant nonmethane hydrocarbon observed over the forest and savanna, even though intense biomass burning activity was occurring several hundred kilometers to the north. The isoprene flux, measured directly from midmorning to noon by a relaxed eddy accumulation technique, was approximately 890 μg isoprene m−2 h−1 from the tropical rain forest and semideciduous forest landscapes and 570 μg isoprene m−2 h−1 from transitional and degraded woodland landscapes. Model estimates derived from satellite landscape characterization coupled with leaf enclosure emission measurements conducted during EXPRESSO compared well with these measured fluxes. Isoprene concentrations and fluxes were used to determine the oxidant balance over the forest and savanna. Radiative transfer calculations indicate that the observed strong vertical gradient of the NO2 photolysis rate coefficient could be explained by the presence of substantial amounts of absorbing aerosols, probably from biomass burning. Chemical (box) model simulations of the planetary boundary layer (PBL), constrained by measured isoprene emission fluxes and concentrations, show that this suppression of photolytic radiation lowers OH concentrations by about a factor of 2 relative to aerosol-free conditions. Consequently, the direct contribution of PBL photochemistry to ozone production, especially from biogenic isoprene, is small.
The Changing Monsoon Extremes and Dynamics: Example in Pakistan

Correspondence to: Shih-Yu (Simon) Wang, Utah Climate Center & Department of Plants, Soils, and Climate, Utah State University, Logan, UT; E-mail: simon.wang@usu.edu. Changing Monsoon Extremes and Dynamics: Example in Pakistan S. -Y. (Simon) Wang , Robert Davies, Robert Gillies , and Jiming Jin Utah Climate Center, Utah State University, Logan, UT Department of Plants, Soils, and Climate, Utah State University, Logan, UT
Evidence of active dinitrogen fixation in surface waters of the eastern tropical South Pacific during El Niño and La Niña events and evaluation of its potential nutrient controls

Biological N2 fixation rates were quantified in the Eastern Tropical South Pacific (ETSP) during both El Niño (February 2010) and La Niña (March–April 2011) conditions, and from Low‐Nutrient, Low‐Chlorophyll (20°S) to High‐Nutrient, Low‐Chlorophyll (HNLC) (10°S) conditions. N2 fixation was detected at all stations with rates ranging from 0.01 to 0.88 nmol N L−1 d−1, with higher rates measured during El Niño conditions compared to La Niña. High N2 fixations rates were reported at northern stations (HNLC conditions) at the oxycline and in the oxygen minimum zone (OMZ), despite nitrate concentrations up to 30 µmol L−1, indicating that inputs of new N can occur in parallel with N loss processes in OMZs. Water‐column integrated N2 fixation rates ranged from 4 to 53 µmol N m−2 d−1 at northern stations, and from 0 to 148 µmol m−2 d−1 at southern stations, which are of the same order of magnitude as N2 fixation rates measured in the oligotrophic ocean. N2 fixation rates responded significantly to Fe and organic carbon additions in the surface HNLC waters, and surprisingly by concomitant Fe and N additions in surface waters at the edge of the subtropical gyre. Recent studies have highlighted the predominance of heterotrophic diazotrophs in this area, and we hypothesize that N2 fixation could be directly limited by inorganic nutrient availability, or indirectly through the stimulation of primary production and the subsequent excretion of dissolved organic matter and/or the formation of micro‐environments favorable for heterotrophic N2 fixation.
EVALUATION OF SETTLEMENTS IN SAND DEPOSITS FOLLOWING LIQUEFACTION DURING EARTHQUAKES

ABSTRACT By examining a bulk of laboratory test data on sands obtained by using a simple shear apparatus, a family of curves was established in which the volumetric strain resulting from dissipation of pore water pressures is correlated with the density of sand and conventionally used factor of safety against liquefaction. Thus, given the factor of safety and the density in each layer of a sand deposit at a given site, the volumetric strain can be calculated and by integrating the volume changes throughout the depth, it becomes possible to estimate the amount of settlements on the ground surface produced by shaking during earthquakes. The outcome of the data arrangements as above was put in a framework of methodology to estimate the liquefaction-induced settlements of the ground. The proposed methodology was used to estimate the settlements at several sites devastated by liquefaction during the 1964 Niigata earthquake. The estimated values of the settlements were examined in the light of known performances of the sand deposits at respective site. It was shown that the proposed methodology may be used for predicting liquefaction-induced settlements with a level of accuracy suitable for many engineering purposes.
The Wrong Side(S) of the Tracks Estimating the Causal Effects of Racial Segregation on City Outcomes

At the metropolitan level there is a striking negative correlation between residential racial segregation and population characteristics -- particularly for black residents -- but it is widely recognized that this correlation may not be causal. This paper provides a novel test of the causal relationship between segregation and population outcomes by exploiting the arrangements of railroad tracks in the 19th century to isolate plausibly exogenous variation in cities' susceptibility to segregation. I show that, conditional on miles of railroad track laid, the extent to which track configurations physically subdivided cities strongly predicts the level of segregation that ensued after the Great Migration of African-Americans to northern and western cities in the 20th century. At the start of the Great Migration, though, track configurations were uncorrelated with racial concentration, ethnic dispersion, income, industry, education, and population, indicating that reverse causality is unlikely. Instrumental variables estimates demonstrate that segregation leads to lower incomes and lower education among blacks. For whites, there is a mix of positive and negative effects: segregation decreases the probability of being a college graduate or a high earner, but also decreases the probability of being poor or unemployed. Segregation could generate these effects either by affecting human capital acquisition of residents of different races and socio-economic groups ('production') or by inducing sorting by race and SES into different cities ('selection'). This paper provides evidence that is most consistent with a combination of both production and selection.
A Test of Recent Inferences of Net Polar Ice Mass Balance based on Long-Wavelength Gravity

AbstractA comprehensive analysis of satellite datasets has estimated that the ice sheets of Greenland, West Antarctica, the Antarctic Peninsula, and East Antarctica experienced a net mass loss of −100 ± 92 Gt yr−1 over the period 1992–2000 and −298 ± 58 Gt yr−1 over the period 2000–11, representing an increase of −198 ± 109 Gt yr−1 between the two epochs. The authors demonstrate that the time rate of change of the degree-four zonal harmonic of Earth's gravitational potential provides an independent check on these mass balances that is less sensitive to uncertainties that have contaminated previous analyses of the degree-2 zonal harmonic [e.g., due to ongoing glacial isostatic adjustment (GIA), solid Earth body tides, and core–mantle coupling]. For the period 2000–11, the signal implied by the ice sheet mass flux cited above is (3.8 ± 0.6) × 10−11 yr−1, whereas the change in the harmonic across the two epochs is (2.3 ± 1.1) × 10−11 yr−1. In comparison, using satellite laser ranging (SLR) data, the authors .
Strong Light Absorption Induced by Aged Biomass Burning Black
Carbon over the Southeastern Tibetan Plateau in Pre-monsoon
Season

Abstract. During the pre-monsoon season, biomass burning (BB) activities are intensive in southern Asia. Facilitated by westerly circulation, those BB plumes can be transported to the Tibetan Plateau (TP). Black carbon (BC), the main aerosol species in BB emissions, is an important climate warming agent, and its absorbing property strongly depends on its size distribution and mixing state. To elucidate the influence of those transported BB plumes on the TP, a field campaign was conducted on the southeast edge of the TP during the pre-monsoon season. It was found that the transported BB plumes substantially increased the number concentration of the atmospheric BC particles by 13 times, and greatly elevated the number fraction of thickly-coated BC from 52 % up to 91 %. Those transported BC particles had slightly larger core size and much thicker coatings than the background BC particles. However, the coating mass was not evenly distributed on BC particles with different sizes. The smaller BC cores were found to have larger shell/core ratios than the larger cores. Besides, the transported BB plumes strongly affected the vertical variation of the BC's abundance and mixing state, resulting in a higher concentration, larger number fraction and higher aging degree of BC particles in the upper atmosphere. Resulted from both increase of BC loading and aging degree, the transported BB plumes eventually enhanced the total light absorption by 15 times, in which 21 % was contributed by the BC aging and 79 % was contributed from the increase of BC mass. Particularly, the light absorption enhancement induced by the aging process during long-range transport has far exceeded the background aerosol light absorption, which implicates a significant influence of BC aging on climate warming over the TP region.
Application of the 190Pt-186Os isotope decay system to dating platinum-group minerals

Constraining the formation age of platinum-group minerals (PGM) in placer deposits has traditionally been very challenging. The 190Pt-186Os decay system, measured by laser ablation multi-collector ICPMS (LA-MC-ICPMS), has been demonstrated as a useful geochronometric tool for detrital PGM grains. However, it is difficult to appraise the method accuracy using detrital PGM. In this thesis two examples are presented that verify the accuracy and precision of the technique in geologically well constrained situations. The age of the Bushveld Complex has been measured using various radioisotope chronometers which yield ages ranging from 1921 – 2165 Ma, although an age of 2054 Ma is widely accepted. We present an accurate isochron age of 2012 ± 47 Ma (2σ, n = 50, MSWD = 1.19) for in situ Bushveld PGM, demonstrating the validity of multi-grain Pt-Os ages. Precision on the Bushveld LA-MC-ICPMS Pt-Os age is comparable to the Re-Os and Rb-Sr ages but data acquisition is easier and less time consuming. Scatter on the isochron may result from analytical artefacts or from post-crystallisation disturbance of the Pt-Os system within Pt-rich PGM grains via exsolution or deformation followed by incomplete sampling of the resulting within-grain heterogeneities. Placer PGM derived from the Meratus ophiolite, southeast Borneo yield a precise Pt-Os isochron age of 197.8 ± 8.1 Ma (2σ, n = 260, MSWD = 0.90). This is consistent with published age constraints and provides the first direct date for the igneous rocks of the Meratus ophiolite, highlighting the utility of the Pt-Os geochronometer as a tool for dating ophiolites, layered intrusions and placer platinum mineralisation despite potential derivation of PGM from various isolated chromitites. Analysis of large PGM populations has allowed improvement on published constraints for Pt/Os inter-element fractionation occurring during ablation analysis of PGE sulphides and alloys. This is estimated to amount to between 2 – 2.5 %.
Wavelet-based image compression and content authentication

In the digital information age, digital content (audio, image, and video) can be easily copied, manipulated, and distributed. Copyright protection and content authentication of digital content has become an urgent problem to content owners and distributors. Digital watermarking has provided a valid solution to this problem. Based on its application scenario, most digital watermarking methods can be divided into two categories: robust watermarking and fragile watermarking. Here, we will concentrate on fragile watermarking of digital images, which is for image content authentication. Our fragile watermarking method is heavily based on the new image compression standard JPEG 2000. We choose a compressed bit stream from JPEG 2000 as the hash of an image, and embed the hash back to the image. The exceptional compression performance of JPEG 2000 solves the tradeoff between small hash size and high hash confidence level. In the authentication stage, the embedded compressed bit stream will be extracted. Then it will be compared with the compressed bit stream of the image to be authenticated. The authentication decision comes from the comparison result. Besides content authentication, we will also show how to employ this watermarking method for hiding one image into another.