bluuebunny/crossref_metadata_2025_split huggingface dataset:
Are Remote Sensing Evapotranspiration Models Reliable Across South American Ecoregions?
Authors: Melo D. C. D. , Anache J. A. A. , Borges V. P. , Miralles D. G. , Martens B. , Fisher J. B. , Nóbrega R. L. B. , Moreno A. , Cabral O. M. R. , Rodrigues T. R. , Bezerra B. , Silva C. M. S. , Neto A. A. Meira , Moura M. S. B. , Marques T. V. , Campos S. , Nogueira J. S. , Rosolem R. , Souza R. M. S. , Antonino A. C. D. , Holl D. , Galleguillos M. , Perez‐Quezada J. F. , Verhoef A. , Kutzbach L. , Lima J. R. S. , Souza E. S. , Gassman M. I. , Perez C. F. , Tonti N. , Posse G. , Rains D. , Oliveira P. T. S. , Wendland E. 
Published: October 2021

AbstractMany remote sensing‐based evapotranspiration (RSBET) algorithms have been proposed in the past decades and evaluated using flux tower data, mainly over North America and Europe. Model evaluation across South America has been done locally or using only a single algorithm at a time. Here, we provide the first evaluation of multiple RSBET models, at a daily scale, across a wide variety of biomes, climate zones, and land uses in South America. We used meteorological data from 25 flux towers to force four RSBET models: Priestley–Taylor Jet Propulsion Laboratory (PT‐JPL), Global Land Evaporation Amsterdam Model (GLEAM), Penman–Monteith Mu model (PM‐MOD), and Penman–Monteith Nagler model (PM‐VI). was predicted satisfactorily by all four models, with correlations consistently higher () for GLEAM and PT‐JPL, and PM‐MOD and PM‐VI presenting overall better responses in terms of percent bias (%). As for PM‐VI, this outcome is expected, given that the model requires calibration with local data. Model skill seems to be unrelated to land‐use but instead presented some dependency on biome and climate, with the models producing the best results for wet to moderately wet environments. Our findings show the suitability of individual models for a number of combinations of land cover types, biomes, and climates. At the same time, no model outperformed the others for all conditions, which emphasizes the need for adapting individual algorithms to take into account intrinsic characteristics of climates and ecosystems in South America.
Evolution of the Koma Bangou Gold Panning Site (Niger) From 1984 to 2020 Using Landsat Imagery
Authors: Abass Saley A. , Baratoux D. , Baratoux L. , Ahoussi K. E. , Yao K. A. , Kouamé K. J. 
Published: October 2021

AbstractThe severe drought of 1983–1984 in the Sahel region, and its socio‐economic impacts for people relying on farming had for consequence the first major gold rush at Koma Bangou in the southwestern part of Niger. Initiated in 1984, the gold panning activities were interrupted from 1989 to 1999 with exploration permits assigned to the mining industry. The site was reclassified at the year‐end 1999 as a gold panning site and artisanal mining resumed until present‐day. Gold panning activities such as ore extraction and cyanide processing produced mining waste including rocks, mine tailings, and treatment residues. Mining waste is a serious environmental, health and safety problem. Multispectral Landsat images (TM4‐5, ETM7+, OLI/TIRS) acquired between 1984 and 2020 were used to map the spatial evolution of waste generated by gold panning activities at Koma Bangou. Different processing methods were tested, including Minimum Noise Fraction (MNF) transform, Band Ratio (BR), and Feature Oriented Principal Component Selection (FPCS). The FPCS applied to hydroxyl‐bearing minerals appears to be most efficient to map gold extraction and cyanidation waste areas. The waste surface associated with ore extraction has increased from 9.43 ha in 1984 to 234.20 ha in 2020, with continuous expansion during the period of clandestine activity (1989–1999). The waste surface associated with cyanidation has increased from 5.56 ha in 2009 (the year of cyanide treatment introduction) to 99.53 ha in 2020. Landsat multispectral imagery proved a suitable data source for monitoring the evolution of gold mining waste and consequences of public policies at Koma Bangou.
Clustering Supported Classification of ChemCam Data From Gale Crater, Mars
Authors: Rammelkamp Kristin , Gasnault Olivier , Forni Olivier , Bedford Candice C. , Dehouck Erwin , Cousin Agnès , Lasue Jeremie , David Gaël , Gabriel Travis S. J. , Maurice Sylvestre , Wiens Roger C. 
Published: October 2021

AbstractThe Chemistry and Camera (ChemCam) instrument on board the Mars Science Laboratory (MSL) rover Curiosity has collected a very large and unique data set of in‐situ spectra and images of Mars since landing in August 2012. More than 800,000 single shot laser‐induced breakdown spectroscopy (LIBS) spectra measured on more than 2,500 individual targets were returned so far by ChemCam. Such a data set is ideally suited for the application of statistical methods for the recognition of patterns that are difficult to observe by humans. In this work, we develop an approach relying on the feature extraction method Non‐Negative Matrix Factorization (NMF) and the repetition of k‐means clustering to classify ChemCam spectra. A strong consistency of the clustering results among the repetitions were found, which allowed us to identify six clusters representing the dominant compositions measured by ChemCam in Gale crater so far. By tracking clusters across the rover traverse from landing to sol 2756, we are able to provide a chemostratigraphic overview of the Gale crater from the ChemCam perspective. Transitions between major geologic groups (such as the Bradbury and the Mt. Sharp groups) are identifiable demonstrating that they are compositionally distinct, consistent with previous work. Compositional differences between their members also appear in the results. Furthermore, a first approach in which a random forest classifier was trained and validated with the obtained cluster assignments, reveals promising results for predicting cluster memberships of new ChemCam LIBS data acquired after sol 2756.
The Fuchuan Ophiolite in South China: Evidence for Modern‐Style Plate Tectonics During Rodinia Breakup
Authors: Huang Si‐Fang , Wang Wei , Kerr Andrew C. , Zhao Jun‐Hong , Xiong Qing , Wang Jian 
Published: October 2021

AbstractSubduction initiation processes, such as those evidenced in the Izu‐Bonin‐Mariana (IBM) forearc crust are a key feature of modern‐style plate tectonics. However, the evidence for this process in the Precambrian is limited, due to the scarcity of ophiolite suites and in particular a lack of typical complete ophiolitic sequences similar to those observed in Phanerozoic ophiolites. Mineral analyses of olivine, orthopyroxene, and chrome spinel from the harzburgite and two types of clinopyroxene from the cumulate gabbro of the Fuchuan ophiolite, South China suggest formation in a Neoproterozoic subduction system similar to the IBM. High temperature (1,000–1,200°C), low pressure along with a high degree of melt extraction (>18%) have been recorded in the harzburgite. This evidence, in conjunction with magma evolution from forearc basalt to boninite to hydrous calc‐alkaline magmatism, recorded in the crustal section of the Fuchuan ophiolite indicates a transition from initial to mature subduction in a forearc setting. Statistical analysis of global ophiolites through time suggests that IBM‐like subduction systems may have successfully operated since at least the latest Neoproterozoic (ca. 1,000 Ma) and be pervasive on Earth from ca. 850 Ma. Additional evidence for Neoproterozoic ophiolites from India, Siberia, and Arabian‐Nubian Shield, which are also similar to the IBM forearc ophiolite, suggests that cold and deep subduction became much more common in the Neoproterozoic (ca. 850 Ma) around the periphery of the Rodinia supercontinent. This IBM‐like subduction system may have acted as the geodynamic trigger for the break‐up of Rodinia.
MJO Initiation Triggered by Amplification of Upper‐Tropospheric Dry Mixed Rossby‐Gravity Waves
Authors: Takasuka Daisuke , Kohyama Tsubasa , Miura Hiroaki , Suematsu Tamaki 
Published: October 2021

AbstractA possibly important dynamical process for the Madden–Julian oscillation (MJO) convective initiation is proposed. An MJO event during the “CINDY2011” field campaign is triggered by eastward‐moving lower‐tropospheric mixed Rossby‐gravity (MRG) wave packets, and its leading precursor is predominance of upper‐tropospheric MRGs in the Indian Ocean (IO). Simple three‐dimensional model experiments reveal that the upper‐tropospheric MRGs in the IO are amplified particularly in the western IO (WIO) by their westward advection and wave accumulation due to the upper‐level convergence in mean easterlies of the Walker circulation. The model also predicts downward dispersion of the amplified upper‐tropospheric MRGs and resultant lower‐tropospheric MRG wave packet formation. This MRG evolution consistently explains the MJO initiation process during CINDY2011, which is further verified by ray tracing for MRGs. Upper‐tropospheric circumnavigating Kelvin waves assist the proposed mechanism by promoting MRG‐wave accumulation (advection) in their westerly (easterly) phases via enhanced zonal convergence and weakened easterlies (enhanced easterlies).
Waves Generated by Discrete and Sustained Gas Eruptions With Implications for Submarine Volcanic Tsunamis
Authors: Shen Yaxiong , Whittaker Colin N. , Lane Emily M. , White James D. L. , Power William , Melville Bruce W. 
Published: October 2021

AbstractSubmarine volcanic eruptions can perturb the water surface and subsequently generate localized tsunamis. Herein waves are produced in analogous laboratory experiments by injections of non‐condensable expanding air into fresh water. By varying source pressures, jet durations and water depths, we obtain two key results. There exists a saturation duration above which the maximum wave height will not increase as the eruption continues. Apart from in extremely shallow or deep water depths, this saturation duration is positively correlated with the source intensity and negatively with the water depth. There also exists a critical water depth where an eruption with a given source intensity can generate the largest waves. When an eruption lasts less than the saturation duration, increasing the eruption duration will increase the critical water depth and the corresponding maximum wave height. The saturation duration and critical water depth are the primary controls on tsunami size and hazard.
Strong Diurnal Pulsing of Cold Clouds in Rapidly Intensifying Tropical Cyclones
Authors: Zhang Xinyan , Xu Weixin 
Published: October 2021

AbstractThe radially outward propagating diurnal signal in the upper‐level clouds (diurnal pulse) is a prominent cyclical feature of tropical cyclones (TCs). This study examines relationships between diurnal pulses and TC intensity changes using satellite Infrared data from 2001 to 2018. The occurrence and duration of diurnal pulses 24 hr prior to or during TC intensity change are strongly correlated with TC intensification rate. Rapidly intensifying (RI) TCs have a markedly higher frequency (60%–80%) of very long‐duration pulse (15 hr) and significantly longer mean pulse duration than steady‐state (40%–50%) and gradually intensifying TCs (50%–60%). Long‐duration pulses are infrequent in weakening TCs (20%–30%). Diurnal pulse frequency and duration are highly correlated with the initial cloud‐top cooling rate and very cold‐cloud fraction in the inner core, but less related to the initial TC intensity. In short, strong diurnal pulsing of cold clouds is an evident signature prior to or during the RI of TCs.
Ice‐Shelf Basal Melt Channels Stabilized by Secondary Flow
Authors: Wearing M. G. , Stevens L. A. , Dutrieux P. , Kingslake J. 
Published: October 2021

AbstractIce‐shelf basal channels form due to concentrated submarine melting. They are present in many Antarctic ice shelves and can reduce ice‐shelf structural integrity, potentially destabilizing ice shelves by full‐depth incision. Here, we describe the viscous ice response to a basal channel—secondary flow—which acts perpendicular to the channel axis and is induced by gradients in ice thickness. We use a full‐Stokes ice‐flow model to systematically assess the transient evolution of a basal channel in the presence of melting. Secondary flow increases with channel size and reduces the rate of channel incision, such that linear extrapolation or the Shallow‐Shelf Approximation cannot project future channel evolution. For thick ice shelves ( m) secondary flow potentially stabilizes the channel, but is insufficient to significantly delay breakthrough for thinner ice ( m). Using synthetic data, we assess the impact of secondary flow when inferring basal‐channel melt rates from satellite observations.
Geological Characteristics and Targets of High Scientific Interest in the Zhurong Landing Region on Mars
Authors: Zhao Jiannan , Xiao Zijun , Huang Jun , Head James W. , Wang Jiang , Shi Yutong , Wu Bo , Wang Le 
Published: October 2021

AbstractWe used imaging, laser altimeter and thermal infrared data to map a 0.5 by 0.5° area containing the landing site of the Zhurong rover of the Tianwen‐1 mission. We analyzed the regional topography and thermophysical characteristics, and identified and characterized cones, impact craters, polygonal troughs, ridges and aeolian bedforms. An absolute model age of 757 ± 66 Ma was obtained for the major unit dominating the study area, younger than previous geological mapping results. We propose several targets of high scientific interest for Zhurong and a stratigraphic model composed of five layers (from bottom to top: Noachian basement, Early Hesperian volcanic ridged plains, Vastitas Borealis Formation materials, rocky materials and loose materials). The geomorphic features identified, the proposed stratigraphy and the regional geological evolution scenario set the stage for the Zhurong rover to continue to carry out its exploration of Mars.
Back‐Arc Extension of the Central Bransfield Basin Induced by Ridge–Trench Collision: Implications From Ambient Noise Tomography and Stress Field Inversion
Authors: Li Wei , Yuan Xiaohui , Heit Benjamin , Schmidt‐Aursch Mechita C. , Almendros Javier , Geissler Wolfram H. , Chen Yun 
Published: October 2021

AbstractThe Bransfield Basin is a young (∼4 Ma) back‐arc basin related to the remnant subduction of the Phoenix Plate that once existed along the entire Pacific margin of the Antarctic Peninsula. Based on a recently deployed amphibious seismic network, we use ambient noise tomography to obtain the S‐wave velocity structure in the Central Bransfield Basin (CBB). Combining with the stress field inverted from focal mechanisms, our images reveal that the CBB suffers a significant extension in the northwest‐southeast direction. The extension is strongest in the northeastern CBB with associated mantle exhumation and weakens to the southwest with decoupled deformations between the upper crust and lithospheric mantle. Such an along‐strike variation of extension can be explained by slab window formation and forearc rotation, which are associated with the Phoenix Plate detachment during the ridge–trench collisions at the southwest of the Hero Fracture Zone.
Improving Nowcasting of Convective Development by Incorporating Polarimetric Radar Variables Into a Deep‐Learning Model
Authors: Pan Xiang , Lu Yinghui , Zhao Kun , Huang Hao , Wang Mingjun , Chen Haonan 
Published: October 2021

AbstractNowcasting of convective storms is urgently needed yet rather challenging. Current nowcasting methods are mostly based on radar echo extrapolation, which suffer from the insufficiency of input information and ineffectiveness of model architecture. A novel deep‐learning (DL) model, FURENet, is designed for extracting information from multiple input variables to make predictions. Polarimetric radar variables, KDP and ZDR, which provide extra microphysics and dynamic structure information of storms, are fed into the model to improve nowcasting. Two representative cases indicate that KDP and ZDR can help the DL model better forecast convective organization and initiation. Quantitative statistical evaluation shows using FURENet, KDP, and ZDR synergistically improve nowcasting skills (CSI score) by 13.2% and 17.4% for the lead time of 30 and 60 min, respectively. Further evaluation shows the microphysical information provided by the polarimetric variables can enhance the DL model in understanding the evolution of convective storms and making more trustable nowcasts.
Turbulence Dictates Bedload Transport in Vegetated Channels Without Dependence on Stem Diameter and Arrangement
Authors: Zhao Tian , Nepf Heidi M. 
Published: October 2021

AbstractVegetation provides habitat and nature‐based solutions to coastal flooding and erosion, drawing significant interest in its restoration, which requires an understanding of sediment transport and retention. Laboratory experiments examined the influence of stem diameter and arrangement on bedload sediment transport by considering arrays of different stem diameter and mixed diameters. Bedload transport rate was observed to depend on turbulent kinetic energy, with no dependence on stem diameter, which was shown to be consistent with the impulse model for sediment entrainment. Existing predictors of bedload transport for bare beds, based on bed shear stress, were recast in terms of turbulence. The new turbulence‐based model predicted sediment transport measured in model canopies across a range of conditions drawn from several previous studies. A prediction of turbulence based on biomass and velocity was also described, providing an important step toward predicting turbulence and bedload transport in canopies of real vegetation morphology.
Mixing Enhancement Mechanisms in Aquifers Affected by Hydropeaking: Insights From Flow‐Through Laboratory Experiments
Authors: Ziliotto F. , Basilio Hazas M. , Rolle M. , Chiogna G. 
Published: October 2021

AbstractThis study presents high‐resolution flow‐through experiments investigating transport processes in a laboratory setup mimicking an aquifer affected by hydropeaking (i.e., abrupt fluctuations in the river stage by the release or storage of water in reservoirs). Highly transient flow conditions were experimentally generated by sudden changes of the water level in two rivers in hydraulic contact with an unconfined aquifer. High‐resolution image analysis and depth‐resolved, high‐frequency sampling at the outlet allowed monitoring of the spatio‐temporal evolution and the breakthrough of a dye tracer plume in the porous medium. The plume spreading and mixing were quantified by moment analysis and entropy‐based metrics of the scalar field. We show that hydropeaking strongly enhances spreading and mixing in the subsurface (up to 249.5% and 41.8% in these experiments) and demonstrate the relevance of considering highly transient flow regimes to properly capture transport and mixing‐controlled biogeochemical reactions at the surface water ‐ groundwater interface.
Impact of the Juan Fernandez Ridge on the Pampean Flat Subduction Inferred From Full Waveform Inversion
Authors: Gao Yajian , Yuan Xiaohui , Heit Benjamin , Tilmann Frederik , van Herwaarden Dirk‐Philip , Thrastarson Solvi , Fichtner Andreas , Schurr Bernd 
Published: October 2021

AbstractA new seismic model for crust and upper mantle of the south Central Andes is derived from full waveform inversion, covering the Pampean flat subduction and adjacent Payenia steep subduction segments. Focused crustal low‐velocity anomalies indicate partial melts in the Payenia segment along the volcanic arc, whereas weaker low‐velocity anomalies covering a wide zone in the Pampean segment are interpreted as remnant partial melts. Thinning and tearing of the flat Nazca slab is inferred from gaps in the slab along the inland projection of the Juan Fernandez Ridge. A high‐velocity anomaly in the mantle below the flat slab is interpreted as relic Nazca slab segment, which indicates an earlier slab break‐off triggered by the buoyancy of the Juan Fernandez Ridge during the flattening process. In Payenia, large‐scale low‐velocity anomalies atop and below the re‐steepened Nazca slab are associated with the re‐opening of the mantle wedge and sub‐slab asthenospheric flow, respectively.
New Paleomagnetic Constraints on the Cretaceous Tectonic Framework of the Antarctic Peninsula
Authors: Gao Liang , Pei Junling , Zhao Yue , Yang Zhenyu , Riley Teal R. , Liu Xiaochun , Zhang Shuan‐Hong , Liu Jian‐Min 
Published: October 2021

AbstractUnderstanding the tectonic framework of the Antarctic Peninsula is hindered by a paucity of paleomagnetic data from key locations. In this study, we present paleomagnetic data from the South Shetland Islands, to the northwest of the Antarctic Peninsula, which provides valuable paleoposition constraints on the Western domain of the Antarctic Peninsula. We report a key reliable paleopole (58.1°S, 354.3°E, A95 = 6.3°) from Livingston Island in the South Shetland Islands at ∼102 Ma. Plate reconstruction models from the Early Cretaceous attach the South Shetland Islands to the Pacific margin of southern Patagonia‐Fuegian Andes at ∼140 Ma. The South Shetland Islands then experienced southward translation to its current position to the northwest of the Antarctic Peninsula following counterclockwise rotation during ∼100–90 Ma. A similar counterclockwise rotation has also been identified from southern Patagonia‐Fuegian Andes but is absent in the Antarctic Peninsula, suggesting a direct affinity between the South Shetland Islands and southern Patagonia‐Fuegian Andes. However, the consistent, almost northward Cretaceous paleomagnetic declination in the Antarctic Peninsula, and the near‐synchronous tectonic‐magmatic history between the Antarctic Peninsula and the southern Patagonia‐Fuegian Andes support an autochthonous continental subduction model for most of the Antarctic Peninsula.
Exploring the Effects of Rooftop Mitigation Strategies on Urban Temperatures and Energy Consumption
Authors: Zonato A. , Martilli A. , Gutierrez E. , Chen F. , He C. , Barlage M. , Zardi D. , Giovannini L. 
Published: October 2021

AbstractThis paper describes and evaluates physical parameterizations accounting for the effect of rooftop mitigation strategies (RMSs) on the urban environment, in the context of the mesoscale model Weather Research and Forecasting (WRF). Through the new implementation, the sensitivity of near‐surface air temperature and building energy consumption to different RMSs is evaluated by means of numerical simulations in idealized urban areas, for typical summer and winter conditions. Rooftop mitigation strategies considered include cool roofs, green roofs, and rooftop photovoltaic panels. The reference case simulations are performed assuming buildings made by bricks, with roof composed of clay tiles. Results indicate that near‐surface air temperature is reduced by cool and green roofs during summer: cool roofs are the most efficient in decreasing air temperature, followed by irrigated green roofs. Photovoltaic panels, instead, induce a temperature increase during daytime and a small decrease during nighttime. Cool roofs reveal to be the most efficient strategy in reducing the energy consumption by air conditioning systems. During wintertime, green roofs maintain a higher near‐surface air temperature than clay tile roofs and largely decrease energy consumption. Even PVPs increase air temperature, as in the summer case. On the other hand, cool roofs reduce near‐surface air temperature during daytime, inducing an increase in energy consumption. The results presented here show that the parameterization schemes implemented in the WRF model can be a valuable tool to evaluate the effects of mitigation strategies in the urban environment.