bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Analysis of Deep Learning Models for Reconstructing GRACE Terrestrial Water Storage Changes over India
Authors: Moudgil Pragay Shourya , Rao G Srinivasa , Maiti Saumen
Published: March 2024

Terrestrial water storage (TWS) anomalies from Gravity Recovery and Climate Experiment (GRACE)  plays a crucial role in identifying global groundwater usage patterns. However, the presence of 33 months of temporal gaps within the GRACE data poses challenges to spatiotemporal analysis. In this study, we explore the feasibility of employing two distinct deep learning models, namely CNN-LSTM and Multi-Layer Perceptron (MLP) based seasonal trend decomposition (STL), to reconstruct GRACE-TWS changes over India. To evaluate model performance, we utilize key metrics such as Pearson correlation (PR), Nash-Sutcliffe Efficiency (NSE), and Normalized Root Mean Squared Error (NRMSE). In a basin-wise comparison, the CNN-LSTM model outperforms the MLP-based STL method. Additionally, we tested the performance of deep learning models for various combinations of input variables, including precipitation, temperature, soil moisture, snow water equivalent, runoff, NDVI, evapotranspiration, and groundwater storage changes. Notably, the model with all input variables exhibited better performance during both training (Median PR = 0.982, Median NSE = 0.958, Median NRMSE = 0.051) and testing (Median PR = 0.956, Median NSE = 0.909, Median NRMSE = 0.086). Conversely, a combination with limited variables (Precipitation + Temperature + NOAH-TWS) showed relatively poor performance during training (Median PR = 0.933, Median NSE = 0.859, Median NRMSE = 0.106) and testing (Median PR = 0.907, Median NSE = 0.816, Median NRMSE = 0.136). Further, the inclusion of groundwater components as model input enhanced model performance, particularly in the arid regions of India.
Seasonal circulation and volume transport in the Gerlache Strait
Authors: Puyal-Astals Laia , Aguiar-González Borja , Veny Marta , Machín Francisco
Published: March 2024

We present the first observational-based assessment of the year-round circulation and volume transport in the Gerlache Strait, a key location for the water mass exchanges occurring along the west Antarctic Peninsula (wAP) between the relatively warm Bellingshausen Sea, flowing northeastward, and the colder Weddell Sea, flowing southwestward. These relatively warm/cold ocean water pathways have been documented to play a major role in the glacier retreat/stabilization of glaciers along the wAP (Cook et al., 2016). Bearing this in mind, we investigate a dataset of direct velocity measurements which were routinely collected along ship tracks from 379 cruises performed by R/V Nathaniel B. Palmer and R/V Laurence M. Gould between 1999 and 2018. A first set of analyses of an earlier version of this dataset was presented in Savidge & Amft (2009), who focused on the summer and winter views of the shelf circulation along the entire wAP. More recently, an updated version of such a dataset addressed the year-round circulation and volume transport of the Bransfield Current in the Bransfield Strait between 1999 and 2014 (Veny et al., 2022).Preliminary results of this work focus on the ocean current variability displayed between 2008 and 2009, two years known in the literature as featuring remarkably opposite Weddell Sea influences along the central wAP (Wang et al., 2022); the former year with a weaker influence than the later one. Ongoing steps include the construction of a high-resolution (~5km) seasonal climatology of the ocean currents flowing through the Gerlache Strait, where the dataset of study ensures a multi-year spatial coverage of volume transport.Key words: Gerlache Strait, Direct Velocity Measurements, Dynamic Structure, Volume Transport, Seasonal and Interannual Variability.References: Cook, A. J., Holland, P. R., Meredith, M. P., Murray, T., Luckman, A., & Vaughan, D. G. (2016). Ocean forcing of glacier retreat in the western Antarctic Peninsula. Science, 353(6296), 283–286. https://doi.org/10.1126/science.aae0017Savidge, D. K., & Amft, J. A. (2009). Circulation on the West Antarctic Peninsula derived from 6 years of shipboard ADCP transects. Deep Sea Research Part I: Oceanographic Research Papers, 56(10), 1633–1655. https://doi.org/10.1016/j.dsr.2009.05.011Veny, M., Aguiar-González, B., Marrero-Díaz, Á., & Rodríguez-Santana, Á. (2022). Seasonal circulation and volume transport of the Bransfield Current. Progress in Oceanography, 204, 102795. https://doi.org/10.1016/j.pocean.2022.102795Wang, X., Moffat, C., Dinniman, M. S., Klinck, J. M., Sutherland, D. A., & Aguiar‐González, B. (2022). Variability and Dynamics of Along‐Shore Exchange on the West Antarctic Peninsula (WAP) Continental Shelf. Journal of Geophysical Research: Oceans, 127(2). https://doi.org/10.1029/2021JC017645
Exploring Mars discrete aurora with synoptic images and movies from EMM EMUS
Authors: Lillis Robert , Chirakkil Krishnaprasad , Deighan Justin , Fillingim Matthew , Jain Sonal , Chaffin Michael , Raghuram Susarla , Holsclaw Gregory , Almazmi Hoor , Brain David , Schneider Nick , Xu Shaosui , Halekas Jasper , Espley Jared , Gruesbeck Jacob , Curry Shannon
Published: March 2024

Benefiting from a large orbit and high sensitivity, the Emirates Mars mission EMUS instrument has provided the first opportunity to synoptically and regularly image Mars’ discrete FUV auroral oxygen emission at 130.4 and 135.6 nm.  Over 15-20 minutes, EMUS produces a) images by slewing its aperture slit across the disk or b) “movies” of narrow regions by staring continuously.Discrete aurora are observed primarily where the magnetic topology is open (i.e. connected to the collisional atmosphere at one end), which occurs where Mars’ crustal magnetic fields are either very weak or primarily vertical.  Discrete aurora show a strong local time dependence, with occurrence % decreasing with increasing solar zenith angle.  The highest occurrences are generally found in the post-dusk sector, before 10 PM SLT, though a few regions (e.g. 60°-70° S, 120°-150° E) are brightest between midnight and 3 AM.   Sinuous discrete auroras (SDA) are enigmatic, sharply-defined filamentary emissions identified in approximately 3% of observations. These emissions intersect Mars' UV terminator, aligning generally away from the Sun, tending to cluster into groups oriented to the north, south, east, and west. The occurrence of SDAs increases with higher solar wind pressure. SDAs have a tendency to form toward the direction of the solar wind convection electric field (i.e., forming in the +E hemisphere). Depending on whether they originate near dusk or dawn, there is a moderate clockwise or counterclockwise "twist" observed in the average orientation of SDAs, respectively. Based on these characteristics, we infer a connection between SDAs and Mars' magnetotail current sheet, suggesting that the emission may be a result of energized electrons within this sheet.Lastly, near the dawn and dusk terminators, discrete aurora often display a preference for formation in regions of either positive or negative crustal magnetic field, depending on IMF direction.  This preference can be used to determine whether a dayside (magnetosheath or photoelectron) or nightside (magnetotail) source of electrons is dominant.  Overall, nightside sources dominate over dayside by 20-40%, although individual radial crustal fields can show strong preferences for day or night sources.  This tells us that local magnetic geometry plays a role in global precipitation patterns.With more than 3000 nightside images and 400 aurora movies collected (totaling more than 12 million pixels) since April 2021, we now have a powerful tool to understand Martian aurora morphologies, variability, and dependence on internal and external drivers. 
Studies related to PM2.5 and PM1 using AS-LUNG Sensor in Kuala Lumpur, Malaysia
Authors: Othman Murnira , Latif Mohd Talib , A Wahab Muhammad Ikram
Published: March 2024

Low-cost sensors are new emerging technologies that has been applied in research related to air pollution. Low-cost sensor for particulate matter was produced by Academia Sinica Taiwan and widely used in Asia due to the research collaboration under Advanced Institute on Health Investigation and Air Sensing for Asian Pollution (AI on Hi-ASAP). Low-cost sensor named AS-LUNG outdoor and portable has been deployed in several studies in Malaysia where AS-LUNG has been used for cooking exposure studies, ambient air studies and indoor air studies. AS-LUNG sensor also managed to record parameters such as PM2.5, PM1, temperature and humidity. AS-LUNG outdoor sensor is usually used for ambient PM measurement while AS-LUNG portable can be used for both indoor and outdoor. The result of studies related low-cost sensor applications especially AS-LUNG sensor definitely shows accurate PM concentration which highest PM concentration was observed during in indoor environment such as dormitory in Kuala Lumpur City Centre. 
Wind-Speed Anomalies and SST Rise: Investigating the Mid-2023 Heatwave Propagation below the sea surface
Authors: Pereira Charlotte , Aguiar-González Borja , Carr Mathew , Machín Francisco
Published: March 2024

   For the study of the marine heatwave that occurred from mid-May to late summer 2023, data provided by AEMET (Spanish Meteorological Agency) for the Gran Canaria Airport and Sea Surface Temperature from Copernicus (products METOFFICE-GLO-SST-L4-REP-OBS-SST and METOFFICE-GLO-SST-L4-NRT-OBS-SST-V2) have been utilized. The employed data include the daily records of meteorological and oceanographic variables from 1982 to 2023.   A climatological normal year has been computed based on wind speed and Sea Surface Temperature (SST) data, calculating the mean value and smoothing the result with a moving average. A drop in wind speed has been observed in periods when the usual Trade winds are active over the eastern margin of the Atlantic ocean, decreasing from 13.8 m/s in early May, to only 3.0m/s in June, falling 5.8 m/s below the calculated average for that time of year. Associated with this decrease in wind intensity, there is a delayed increase in SST, reaching an average of 2.3 ºC above normal throughout the summer. Even after a subsequent increase in wind intensity, SST does not drop below normal values for the rest of the year. This relationship between a decrease in the wind intensity and an increase in the SST would suggest that the heat is being accumulated in the sea surface. We hypothesize that winds did not facilitate heat transfer from the sea surface in the form of sensible heat during a period when sensible heat is usually released from the ocean to the atmosphere.   Under this scenario, with a lack of strong winds, mixing in the first layers of the water column is not effective, and the surface temperature measured from satellites is capturing a phenomenon that might mislead the deep-reaching extent of the anomaly. In ongoing analyses, we explore the impact on the water column affected by this abnormal increase in the sea surface temperature by using data provided by Argo floats profiling in the vicinity of the Canary Islands.
Comparing fluid flow mechanisms in reservoir rocks to improve subsurface pollutant remediation
Authors: Eriksson Sandra , Minto James , Edlmann Katriona , Johnson Gareth , Roberts Jennifer , Shipton Zoe
Published: March 2024

In order to reach carbon neutrality, a drastic increase in subsurface carbon storage is essential. During the storge site selection process, sites are assessed based on overall security for long-term storage, and any remaining risks require a risk assessment with leakage mitigation plan. With an increase in large scale carbon storage, there is an increased chance of leakage and the potential for contamination of drinking water aquifers above the storage reservoir. In such a scenario, subsurface sweeping via the pumped injection of large volumes of water would be the most suitable method for remediation, yet this comes with issues of tailing and rebound occurring after the treatment has stopped, necessitating the injection of large volumes of water, over long time-scales, which significantly increases both the cost and carbon footprint of the remediation operation. With this study we look at how modified pumping techniques may improve sweeping to minimise rebound, but also how to minimise use of water.The pumping techniques used in this study were continuous flow and pulsed flow. The pulsed flow was divided into two types, cyclic flow and rapid pulses. Cyclic flow has long breaks and relies on diffusion, whereas rapid pulses rely on vortices created in the pore spaces to increase mixing. The rock types used for the experiments were Clashach sandstone which represented a homogeneous rock, and Wattscliffe Lilac sandstone, representing a heterogeneous rock. The Clashach sandstone is quartz dominated and has a porosity of ca. 24 % with an overall uniform grain size and pore size, as well as well-connected pores. The Wattscliffe Lilac sandstone has a more heterogeneous mineralogy with a porosity of ca. 21 % and varied grain size, pore sizes, and pore connectivity. The different rock types were chosen based on their distinctly different pore structure to aid in understanding how heterogeneity impacts the different flow mechanisms. The cores were prepared at 4 cm long and just under 5 mm wide, covered in heat shrink tubing then cast in resin in order to prevent bypass flow, and optimised for pore-scale XCT imaging at injection pressures of up to 2 MPa. To study the recovery behaviour of the different flow types through the rock cores, fluorescein was used as a tracer and measured in a flow-through fluorometer. The resulting breakthrough curve, tailing, and total recovery was then used to determine which pumped flow method was the most efficient in terms of: 1) remediation of fluorescein, 2) water usage during remediation, and 3) speed of remediation. These different factors of efficiency can be crucial in determining which pumping method is used to remediate a contamination site.
Mapping daily evapotranspiration (2003-2018) based on a modified universal Ts-VI triangle method in the source region of Yangtze river on the Qinghai-Tibetan Plateau
Authors: Li Yan , Zhao Lin
Published: March 2024

The source region of Yangtze river has experienced permafrost degradation and ecological deterioration since 1980s. Accurately estimating the evapotranspiration (ET) and analyzing the spatiotemporal variation in the region is crucial for understanding the change in permafrost and ecological environment. The universal Ts-VI model, transforming the Ts-VI feature space from regional to pixel scale, has been performed over a poorly gauged region with arid ecosystems in the Qinghai-Tibetan Plateau with high spatial resolution and daily continuity. However, the aerodynamic resistance formulation in this universal Ts-VI model only holds true under neutral stability conditions. This study proposes a scheme for improving the estimation of ET based on the universal Ts-VI model by integrating an aerodynamic resistance formulation without the assumption of the neutral stability conditions. The daily ET in the source region of Yangtze river on the Qinghai-Tibetan Plateau from 2003 to 2018 is achieved based on the modified universal Ts-VI model by using the MODIS, Daily 1-km all-weather land surface temperature dataset for Western China (TRIMS LST-TP), and China meteorological forcing dataset (CMFD) and is evaluated by comparing it with eddy covariance measurements in two sites located in permafrost, modeled ET from original universal Ts-VI model, and a readily available daily ET product. Our results indicate that incorporating the aerodynamic resistance formulation without requirement of neutral stability conditions into the universal Ts-VI model can improve the estimation of ET in the plateau of cold and arid region and thus provide more accurate ET maps for study of permafrost degradation and ecological deterioration.
Assessing the Accuracy and Feasibility of Ambient Noise Tomography for Copper Exploration: Insights from Synthetic Data Generation with Realistic Geological Models
Authors: Gal Martin , Oliver Gerrit , Lecocq Thomas , Gunner Grace
Published: March 2024

In the last decade, passive seismic techniques have found use in the mineral exploration sector. In particular, ambient noise tomography is a low cost viable option that can outperform competing geophysical methods when imaging down to a few kilometers depth. However, at present it does not belong to the core approaches (e.g. magnetic, gravity, etc.) mainly due to a lack of experience in the industry. Novel approaches often go through a period of testing where the industry is familiarized with the technique and expectations are "adjusted". In order to speed up this testing period, an extensive review of the technique and its capabilities for real geological settings is required.In this work, we build geological models of well known mineral deposits and generate ambient noise cross correlation functions (ccfs) for synthetic deployments. The ccfs are then used in a state of the art fully probabilistic ambient noise tomography to assess the strengths and weaknesses of this technique. This work will allow the industry to better understand the methods capabilities and adjust their expectations for exploration purposes. 
Machine Learning in Igneous Petrology and Volcanology: State-of-the-Art and Perspectives
Authors: Petrelli Maurizio
Published: March 2024

The work reports on the state-of-the-art and future perspectives of Machine Learning (ML) in igneous petrology and volcanology. To do that, it starts reviewing established methods that mainly concern clustering, dimensionality reduction, classification, and regression. Among them, clustering and dimensionality reduction are particularly valuable for decoding the chemical record stored in igneous and metamorphic phases and to enhance data visualization, respectively. Classification and regression tasks find applications, for example, in petrotectonic discrimination and geothermobarometry, respectively. The main core of the discussion will consist of depicting the next future for ML in petrological and volcanological applications. I propose a future scenario where ML methods will progressively integrate and support established petrological and volcanological methods in boosting new findings, possibly providing a paradigm shift. In this framework, the use of multimodal data, data fusion, physics-informed neural networks, and ML-supported numerical simulations, will play a significant role. Also, the use of ML hypotheses formulation and symbolic regression could significantly boost new findings. In the proposed scenario, the main challenges are: a) progressively link machine learning algorithms with the physical and thermodynamic nature of the investigated processes, b) make deep learning algorithms more transparent, as they often operate as “black boxes,” c) advance in exploring cutting edge tools that rise from researches in Artificial Intelligence, and overall, d) start a collaborative effort among researchers coming from different disciplines in research and teaching.
Lithospheric Structure beneath Northeastern Tibet Plateau and Sichuan Basin revealed by S-Receiver Function Imaging 
Authors: Zhang Yaoyang , Chen Ling , Ai Yinshuang , Fang Hui , Wang Gang
Published: March 2024

    Based on the seismic data of 60 portable stations and 90 permanent CEA stations in the northeastern Tibet Plateau and adjacent regions, we utilized the wave equation post-stack migration method of S-receiver function to image the lithospheric structure of northeastern Tibet Plateau and the Sichuan Basin.Fig. 1 Distribution of the seismic stations and imaging profile    The imaging results show that the Moho in the northeastern Tibet Plateau is deeper than 50 km, and it gradually becomes shallow along the profile to the southeast until reaches about 45 km below the Sichuan Basin. The negative anomaly signals corresponding to the Lithosphere and Austhenosphee Boundry (LAB) are obvious in most areas, but under the Sichuan Basin, there are many strong negative anomaly signals in the migration images of different frequencies. In general, the LAB along the profile is undulating and discontinuous: The lithosphere is deeper in the southern Qilian Orogenic Belt, up to ~200 km, with no significant change at the boundary between the Qilian Orogenic Belt and the western Qinling Orogenic Belt. The lithosphere gradually thinned to ~150 km beneath the western Qinling Orogenic Belt, with a step of ~100 km at the tectonic boundary between the Qinling Orogenic Belt and the Songpan-Garze block, and the signal intensity is obviously weakened. LAB was maintained at this depth level until near the Longmenshan Fault, and the lithosphere thickened again to ~190 km after entering the Sichuan Basin. Moreover, there are two discontinuities within the lithosphere of the Sichuan Basin, with depths of ~100 km and ~140 km, respectively, and the latter becomes shallower to ~110 km in the western margin of the Sichuan Basin. Our observations of mid-lithospherci discontinuity (MLD) beneath the Sichuan Basin provide further evidence that the cratonic lithospheric mantle is generally stratified.Fig. 2 The migration results of the profile    It is proposed that the lithospheric thinning along the eastern margin of the Songpan-Garze Block may be related to the eastward flow of hot mantle materials beneath the eastern Tibet Plateau. Blocked by the Ordos block and the Sichuan Basin, which have preserved the ancient and rigid craton roots, the eastward flow of mantle materials from the Tibet Plateau will turn to the west of the two blocks. A small part of the blocked mantle material migrates eastward to the Qinling Orogenic Belt, while most of it migrates southward clockwise along the mantle flow path to the west of the Sichuan Basin. The lithosphere in the eastern margin of the Songpan-Garze block, heated by the mantle flow, will be subjected to thermochemical erosion and destruction in the process of collision with the Yangtze craton, and is more likely to be delaminated, resulting in significant thinning and destruction under long-term action.
Temporal fluctuations scaling, multifractality and Tweedie distributions of solar energy in insular context
Authors: Calif Rudy , Andre Maïna
Published: March 2024

Solar energy is an intricate phenomenon, especially within tropical insular locations, where this energy source demonstrates significant fluctuations across various short-term timeframes and spatial dimensions. Research on the stochastic characteristics of solar energy is gaining momentum in the scientific literature, revealing signs of scaling properties despite its inherent complexity. This paper sequentially delves into the examination of temporal fluctuations scaling and multifractal properties of irradiance for tropical insular sites (Guadeloupe, Réunion, Hawaï). By analogy with Taylor law performed on several complex process, an analysis of temporal fluctuations irradiance scaling properties is proposed. The results showed that the process of intradaily variability obeys Taylor’s power law for every short time scales and several insolation conditions. This approach elucidates the relationship between the variance of fluctuations and the mean with exponent between 1 and 2. This could confirm the relevance of Tweedie Convergence Theorem in a manner related to the central limit theorem; a mathematical basis for Taylor’s power law, 1/f noise and multifractality according to Kendal and Jørgensen [1].Through various multifractal analysis techniques, including MFDFA, wavelet leader, structure functions, and arbitrary order Hilbert spectral analysis, on global solar radiation sequences, the intermittent and multifractal properties inherent in global solar radiation data have been brought to light across  scales ranging from one second to few hours and all intensities.The understanding the dynamics of irradiance fluctuations is essential in various fields, including atmospheric science, remote sensing, and renewable energy. The results of these properties can help improve the modeling and prediction, which is crucial to optimally integrate PV onto electrical grids. ReferenceW. S. Kendal and B. Jorgensen, Tweedie convergence: A mathematical basis for Taylor's power law, 1/f noise, and multifractality. Phys. Rev. E 84, 066120, 2011. DOI. https://doi.org/10.1103/PhysRevE.84.066120. 
Ocean liming in eutrophic vs. ultraoligotrophic environments and the response of algal calcifiers
Authors: Basso Daniela , Bazzicalupo Pietro , Varliero Selene , González Jose , Serret Pablo , Pitta Paraskevi , Alcaráz Paulo , Penín Alejandro , Macchi Piero , Raos Guido , Barbaccia Eleonora , Magiopoulos Iordanis , Tsiola Anastasia , Romano Filomena , Valsecchi Silvia , Azzellino Arianna
Published: March 2024

Our commitments to limit future global warming to below 2°C of the pre-industrial level are clashing with demonstrably insufficient present-day efforts to reduce CO2 emissions. The development and implementation of Negative Emission Technologies (NETs), enabling a massive and fast CO2 Removal (CDR), represent the most promising strategy to support an effective mitigation of the ongoing climate change within the next decade. Marine CDR (m-CDR) encompasses those technologies exploiting the ocean CO2 storage potential, and there is an increasing number of international initiatives aimed at assessing their possible impact on marine communities. Ocean liming consists in spreading alkaline substances, such as calcium hydroxide (slaked lime), on surface ocean waters. Slaked lime reacts with surface marine waters by triggering m-CDR from the atmosphere and ocean alkalinity enhancement, thus contrasting ocean acidification. Although ocean liming has already been assessed as chemically effective and economically sustainable, the scientific scrutiny of its potential impacts on the ocean biota has just started. Previous laboratory and mesocosm experiments showed the occurrence of transient pH peaks, which may impact the pelagic ecosystem by selecting less sensitive species, and runaway precipitation of aragonite particles after concentrated and repeated liming, which reduces the efficiency of CDR and negatively affects both plankton and benthos by mechanical clogging and choking. Nutrients exert a major control on primary producers, and higher salinity may affect the carbonate kinetics by facilitating CaCO3 precipitation. For these reasons, two mesocosm experiments of liming, funded by the EU2020 project AQUACOSM-plus and the OACIS-initiative of the Fondation-Prince-Albert-II-de-Monaco, were conducted with a comparable experimental design at the CIM-ECIMAT (University of Vigo) and CRETACOSMOS (Hellenic Centre for Marine Research) facilities. The aim was to contrasting the response to ocean liming of the eutrophic Ría de Vigo upwelling system (eastern Atlantic) and the eastern Mediterranean ultraoligotrophic and more saline setting. The preliminary results of repeated additions of slaked lime in the two different types of marine coastal waters, and the response of calcareous nannoplankton and benthic calcareous red algae (coralline algae) to the observed chemical changes are presented here, suggesting the need to optimize and modulate the mCDR techniques, in order to meet the specific geochemical and biological characteristics of the different water bodies.
Interpretable Transformer Neural Network Prediction of Diverse Environmental Time Series Using Weather Forecasts
Authors: Orozco Lopez Enrique , Kaplan David
Published: March 2024

Transformer Neural Networks (TNNs) have caused a paradigm shift in deep learning domains like natural language processing and gathered immense interest due to their versatility in other fields such as time series forecasting (TSF). Most current TSF applications of TNNs use only historic observations to predict future events, ignoring information available in weather forecasts to inform better predictions, and with little attention given to the interpretability of the model’s use of environmental input factors. This work explores the potential for TNNs to perform TSF across multiple environmental variables (streamflow, stage, water temperature, and salinity) in two ecologically important regions: the Peace River watershed (Florida) and the northern Gulf of Mexico (Louisiana). The TNN was tested (and uncertainty quantified) for each response variable from one- to fourteen-day-ahead forecasts using past observations and spatially distributed weather forecasts. Additionally, a sensitivity analysis was performed on the trained TNNs’ attention weights to identify the relative influence of each input variable on each response variable’s prediction. Overall model performance ranged from good to very good (0.78
Mapping, Attribution, and Environmental Effects of Woody Plant Encroachment in Grasslands under Climate Change and Human Activities
Authors: Wang Jie , Chang Chuchen , Wang Xu , Yang Jilin , Xiao Xiangming
Published: March 2024

Woody plant encroachment (WPE) into grasslands has been occurring globally and may be accelerated by climate change and human activities in the future. There are limited studies to document this ecological process and hamper our understanding to make sustainable management approaches for grassland conservation.  Here, we improved our previous studies on woody plant encroachment in the grasslands of Oklahoma, USA.  This study (1) summarized the detection of woody plant encroachment into grasslands over the typical regions in global through PALSAR, Sentinel-1, Sentinel-2, and Landsat images; (2) examined the drivers of woody plant encroachment into grasslands at local and global scales; and (3) developed approaches to quantify the effects of woody plant encroachment into grasslands on carbon, water, and local land surface temperature. The results provide some insights to understand the process and assocaited drivers of woody plant encroachment during the last decades and the roles on carbon and water cycles and the local environment.
Evaluation of Standalone In-situ Simulations of Frozen Soil
Authors: Luo Zhicheng , Ahrens Bodo , Risto Danny , Parmar Mittal
Published: March 2024

The performance of a climate model to reproduce frozen soil depends on the modeled atmospheric forcing and the parameterizations in the land surface. Due to the complex land-air interactions caused by snow and soil freezing and thawing, biased simulations of climate models may be compensated or amplified by errors in land surface models. This may lead to a misjudgment of the simulation capabilities of the land surface model itself, especially when we are trying to improve the overall performance of the climate model without being able to balance the results in frozen soil. In order to separately investigate the simulation performance of the land surface model in the frozen soil region, we conduct simulations using the stand-alone land surface models CLM5, TERRA, and JSBACH at representative sites in Siberia, Alaska, and the Tibetan Plateau and explore the performance of the models from daily to interannual scales using the same atmospheric forcing and initial conditions.The main evaluation objects will be the insulating effect of snow, soil energy balance, and soil moisture transportation to a depth of 3 meters below the ground surface. We look forward to the offline simulation experiments to evaluate the accuracy of different land surface model simulations, the optimal soil hydrothermal parameterization scheme, and important physical processes that may be neglected by the models’ prediction of frozen soil in daily and monthly time scales.
The effects of near-surface turbulence on CO2 flux at the ocean-atmosphere boundary 
Authors: Ostiguy Josiane , Musgrave Ruth , Sutherland Graigory , Wallace Douglas , ten Doeschate Anneke
Published: March 2024

Ocean alkalinity enhancement (OAE) seeks to store carbon in the ocean as bicarbonate or carbonate ions and thus accelerates CO2 uptake from the atmosphere. Near-surface ocean turbulence is an important driver of CO2 uptake by the ocean as it affects the rate at which air-sea gas exchange occurs. Turbulent mixing can also cause high alkalinity water to sink out of the mixed layer, where it will no longer be in contact with the atmosphere. In this presentation we will show the results of high resolution numerical simulations in which alkalinity and dissolved inorganic carbon are advected in a turbulent mixed layer. By coupling the physics to a simple carbonate system solver, we evaluate the potential impact of surface turbulence on CO2 flux into the ocean. We explore the impact of ocean surface processes on the evolution and downwards diffusion of a surface alkalinity addition as influenced by different wind, temperature and precipitation conditions. The CO2 flux is computed according to both an empirical and a physically derived parameterization, and an estimate of the sensitivity of the total CO2 flux to the choice of parameterization is presented.
Rice Field Detection by Dual Polarization SAR Images 
Authors: Tseng Kuo-Hsin , Yang Jui-Han
Published: March 2024

Paddy rice plays a significant role in Asian agriculture, particularly in Taiwan. However, monitoring parcel-level activities and quantifying potential yield during the two crop cycles present challenges. The application of remote sensing to track paddy phenology emerges as a valuable strategy for improving crop management and ensuring food security. Synthetic Aperture Radar (SAR) satellites, among various spaceborne sensors, provide timely and extensive information unaffected by cloud cover. This study aims to extract time series data on paddy-specific phenology using dual-polarized SAR data and subsequently map paddy rice parcels in Taiwan. The process involves three primary steps: (1) Identifying phenological curves in training sites based on the temporal behavior of SAR backscattering coefficients; (2) Utilizing signal decomposition to analyze periodic patterns; (3) Recognizing rice fields by identifying the start and end of each crop cycle in the time series; (4) Validating the results with in situ data. In our preliminary findings, the accuracy in certain townships in western Taiwan achieves a kappa value of >0.6, with an overall accuracy exceeding 0.8. Additionally, we aim to unveil potential connections among crop cycles, groundwater changes, and land subsidence.
Climate Risk Assessment Framework for Tornadoes
Authors: Zarekarizi Mahkameh , Ly Amina , Balaji Bharathan , Branch Esther , Weldemariam Kommy
Published: March 2024

Tornadoes are low-probability high-consequence hazards that are capable of causing significant damages to communities. Future projections of tornadic events are challenging to estimate since tornadoes usually form at scales far less than typical global climate model (GCM) resolutions. As a result, tornado projections are uncertain which can compromise the confidence in downstream risk management for business decision making. This study proposes an approach to estimate and quantify the uncertainty of future tornado risk and improves the representation of uncertainty by incorporating downscaling uncertainty as well as GCMs and internal variability uncertainties. We use our previously-developed climate risk assessment and benchmarking framework which facilitates estimation of climate risk projections for a range of hazards and includes rigorous benchmarking and validation mechanisms to increase confidence in outcomes. We quantify tornado risk using Tornado Weather Condition (TWC); a metric that assesses ingredients of tornadic events. We project TWC for 2030-2070 under RCP8.5 scenario using an ensemble of downscaled projections of relevant climate variables. We validate our outputs using historical observations and benchmark results from various climate projection sources. Our work contributes to future tornado risk studies by benchmarking different GCM sources and better representing uncertainty sources. 
Assessing the environmental benefits of biochar application in agriculture: Insights from lifecycle assessment
Authors: Adhikari Sirjana , Mahmud M A Parvez , Moon Ellen , Timms Wendy
Published: March 2024

Organic waste-derived biochar has been proven to have a significant potential for soil improvement, with recent results from this group showing evidence for improved water holding capacity, carbon stability and exchangeable cations. However, to contextualise these benefits it is important to consider environmental impacts during each stage of life cycle for the product.In this study, a cradle-to-gate life cycle assessment (LCA) was performed, comparing a common use for garden organics (composting) to two alternative scenarios. One involved converting over-sized compost screenings (otherwise considered waste) to biochar as a supplementary product from the process, and the other involved converting garden organics directly to biochar as an alternative product.LCA was conducted using ReCiPe2016 impact assessment method in OpenLCA software. Data for assessment were collected from the participating industries and Ecoinvent database. Sensitivity analysis considering different transport distances was carried out and finally an optimum transport distance with the lowest environmental impacts was recommended. Additionally, physico-chemical characterisation and carbon stability assessment were conducted to provide a comprehensive idea about the overall benefits of organic waste-derived biochar for soil and climate.Our results revealed that global warming was increased from 675 kgCO2eq during composting of garden waste to 1017 kgCO2eq where over-sized screenings of compost is converted to biochar as a value-added product. Direct conversion of organic waste to biochar showed reduced global warming impact of 428 kgCO2eq compared to the previous two scenarios. Among 16 environmental impact indicators studied, the magnitude of 10 impact indicators increased with transport distance, while the remaining six indicators were not influenced by transport distance.Soil application of biochar from organic waste has multiple co-benefits, that can be short and/or long term. Nevertheless, this study emphasises that research focused on agricultural application of biochar needs to be coupled with LCA or other holistic assessments for a comprehensive evaluation of net environmental impacts and benefits that consider the processes involved in sourcing of feedstock, biochar production, transport, and application.
Multi-GPU accelerated parallel modelling for geophysical electromagnetic inversions 
Authors: Dong Hao , Sun Kai
Published: March 2024

The forward modelling for curl-curl equations is the fundament for time-harmonic electromagnetic (EM) problems in geophysics. The simulations with the discretized partial differential equations (PDE) are computationally intensive and crucial to practical geophysical EM problems like Magnetotelluric/Controlled Source EM. However, most published algorithms for curl-curl PDEs are still CPU-based and cannot utilize the rapid development of modern large-scale multi-GPU parallel architectures. Based on previously proposed CPU-based divergence-free modelling algorithm, we develop a hybrid parallel paradigm to exploit the high-throughput of interconnected heterogenous parallel systems equipped with multiple GPUs. The large sparse linear system derived from the staggered-grid finite-difference approximation of curl-curl problem is decomposed into sub-domains and solved efficiently with a mixed-precision Krylov subspace GPU algorithm in parallel. To demonstrate how the practical inversion problems can be substantially accelerated, we test the new algorithm with both the synthetic and real-world 3D models, for forward/adjoint calculations. The test results show a promising ~3.5x improvement regarding the computation speed on a small NVIDIA® HGX based system, over a conventional CPU-base server cluster with 12 nodes. This may significantly reduce the computation time and carbon footage for large-scale frequency domain EM inversion problems and brings the possibility of near real-time EM imaging, as in engineering and environmental applications.
Continuing wetland drainage: drivers, effects, and the role of science-based partnerships and understanding
Authors: Baulch Helen , Loring Phil , Spence Christopher , Miranda Lauren , Selby Don , Whitfield Colin
Published: March 2024

The prairie pothole region of North America has been described as a breadbasket for the world, and a ‘duck factory’ for North America, reflecting the tremendous ecosystem services associated with the vast agricultural lands, and millions of pothole wetlands in the region.  Pressure to increase agricultural outputs and profitability has led to accelerating wetland drainage, leading to a wicked problem worsened by the lack of enforcement of existing policy and vast numbers of unlicensed drainage projects.Responsive to questions from partners, we embarked on a multi-dimensional research program to understand options for managing the drainage of prairie wetlands.  Novel ecosystem service models, based upon the unique hydrology of the region demonstrate important threats of drainage, including flooding, increased nutrient export, and profound impacts on habitat and biodiversity.  Expert-driven scenario development also shows potential for dire changes in the region associated with climate and land use change.  Importantly, there are fundamental differences among stakeholders in their understanding of how the system works, leading to divergent interpretations of the benefits, and consequences of drainage.  Not surprisingly, wetland drainage has led to conflict, as power dynamics and the effort to coordinate drainage approvals have contributed to winners, losers, and those without voice. However, in some cases drainage conflicts may simply be a resurgence of long-standing disputes over varied issues. While interdisciplinary and transdisciplinary work has helped understand the context of wetland drainage in this vast geographic area, problems, and possible ways forward, a weak policy environment is expected to persist because of local ideologies for limited government intervention, a highly politicised environment with strong power imbalances and strong government support of the agriculture sector.  Our work, guided by stakeholders since project inception to inform decision-making, demonstrates significant impacts of drainage with tangible policy implications, yet concerns have emerged about the role of science and representation of science in the policy process. While transdisciplinary research has clear benefits, it is not a panacea in complex, multi-sector, and conflict-prone arenas such as this. 
Multiple benefits of biochar in agrivoltaics including rainfall harvesting and water balance 
Authors: Zhou Zibo , Timms Wendy , Adhikari Sirjana , Joseph Stephen
Published: March 2024

Biochar as a carbon-negative product from organic waste increases porosity and water availability when deployed and mixed with soil, as one of many benefits for agrivolatics projects. Biochar can mitigate climate change by locking away carbon in concrete and during steel production, supporting food security and a circular economy, producing composites for water treatment and nutrient availability, and restoring soils affected by sodicity or contaminants. However, the utilization of biochar in combined farming and large-scale solar PV projects (i.e., agrivoltaics) provides more opportunities such as credits for carbon dioxide removal (CDR) and increased land-use efficiency. This project at a 7-megawatt solar PV (14-hectare) mixed-use farm at Deakin University in Australia aims to evaluate how biochar could contribute to agrivoltaics, particularly its influence on soil moisture, nutrient availability, and pasture productivity. This presentation focuses on part of the datasets, with initial results for water availability in the soil and pasture for sheep grazing. We applied biochar into a hand-dug trench along the drip line of PV panels, with several reference sampling sites (0.6m deep holes) beyond the pasture that is shaded by the panels. The trench was 0.6 m deep and 0.3 m wide, with 0.1 m of drainage sand at the base, a 0.3 m thick layer of mixed straw-biochar followed by 0.1 m of biochar particles, and 0.1m of soil and grass. Pasture treatments of liquid biochar and fertilisers followed installation. Soil moisture sensors were installed in the trench and sampling sites at 0.1, 0.3, and 0.5 m below ground level, and volumetric soil water content (V-SWC %) was recorded every 15 minutes. The initial results showed that the biochar trench in the mid-depth zone (~0.3m below the ground) can retain ~45% soil moisture after initial rainfall events. The maximum value of V-SWC in the bottom zone of the biochar trench was 47%. Similarly, V-SWC trends at other sites indicated that the middle and bottom zones can hold water for a period of time after rainfall occurs and values were up to 20%. Ongoing analysis will include variations of soil carbon and nitrate and the chemistry of leachate water that is collected from piezometers that were installed in the sand base of the trenches for mini-monitoring. The findings of this project will be useful for wide-scale applications of biochar on agrivoltaics or farming projects in environments sensitive to water balance. Biochar in soils can act as a sponge to store more water, slow down water flows in rivers, and increase groundwater recharge to shallow aquifers. This could ensure local catchments are more resilient to dry periods while benefiting ecosystems, and production of renewable energy and farmland.  
Reconstructing Tropical Pacific Variability During the Last Glacial Maximum Using Individual Foraminifera: An Investigation of ENSO Flavors 
Authors: Rustic Gerald , Rosenheim Emma , Slotter Jessica , Hill Kirsten
Published: March 2024

The El Niño Southern Oscillation (ENSO) dominates tropical climate variability. While it is defined by alterations in sea surface temperatures in the eastern and central tropical Pacific, ENSO influences temperature and precipitation patterns across the globe through a network of atmospheric and oceanic teleconnections. Whether ENSO is controlled or responds to external climate factors has long remained elusive, in large part due to the lack of paleoclimate evidence of tropical variability during different climate states. Here we utilize the geochemical signatures of planktic foraminifera to reconstruct eastern and central tropical variability during the last glacial maximum (LGM), some 20-25,000 years ago. Climate conditions during the LGM were very different, featuring atmospheric CO2 concentrations, global temperatures, and sea level all substantially lower than today. However, precessional forcing, thought to be a potential control on ENSO expression, was similar to modern orbital configuration. Our reconstruction spans the central and eastern tropical Pacific during this key time frame and assesses how the patterns of variability - or ENSO ‘flavors’ - may have changed. We compare our spatial reconstructions of variability to changes in the equatorial Pacific thermocline and test hypotheses of thermocline control of ENSO. We explore the evolution of the eastern and central Pacific thermocline, and how their relationship may be an additional factor in influencing ENSO expression. Our results provide key insights into the evolution and history of tropical variability under differing background climate states, providing context for modern ENSO behavior and prediction.