bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ 13C isotope labelling of maize to determine root carbon inputs to the soil.
Authors: Fernández Balado Celia , Ziss Elisabeth , Hartmann Ferdinand , Hood-Nowotny Rebecca
Published: February 2023

Soil organic carbon (SOC) depletion mainly affects croplands, and it reduces the function of soil to control erosion, to hold water and to store carbon. Hence, arable production needs adaptation of restorative practices to increase C sequestration. Roots are key for sustainable agriculture because they are the main precursors of SOC. Increased and deeper roots are a viable option to maximize carbon input to the soil to enhance SOC. However, there is a lack of data on the extent and distribution of roots for different crop types under different management conditions. This study aimed to quantify root carbon inputs and sequestration potential of maize as well as to determine root biomass and architecture under different organic amendment applications. Maize was labelled with 13C-CO2 in the field at the beginning of the growing period. Leaf, root, and soil subsamples from labelled and unlabelled plants were taken during the three weeks after labelling. The carbon distribution and turnover in the investigated pools was assessed by analysing 13C by Elemental Analyzer Isotope Ratio Mass Spectrometer (EA-IRMS). Furthermore, to test the effect of the organic amendments on root growth, maize was grown in an adjacent field with identical conditions with the following treatments: (i) control, (ii) biochar (iii) compost and (iv) NPK. At the end of the growing period, roots were excavated to 30 cm depth and prepared for biomass and root architecture determination. The data collected will allow us to determine carbon distribution and turnover in the investigated pools and assess total C inputs to the soil. Moreover, it will allow us to assess whether the management practices investigated can be used to enhance root C input.
Algorithmic optimisation of key parameters of OpenIFS
Authors: Tuppi Lauri , Ekblom Madeleine , Ollinaho Pirkka , Järvinen Heikki
Published: February 2023

Numerical weather prediction models contain parameters that are inherently uncertain and cannot be determined exactly. Traditionally, the parameter tuning has been done manually, which can be an extremely labourious task. Tuning the entire model usually requires adjusting a relatively large amount of parameters. In case of manual tuning, the need to balance a number of requirements at the same time can lead the tuning process being a maze of subjective choices. It is, therefore, desirable to have reliable objective approaches for estimation of optimal values and uncertainties of these parameters. In this presentation we present how to optimise 20 key physical parameters having a strong impact on forecast quality. These parameters belong to the Stochastically Perturbed Parameters Scheme in the atmospheric model Open Integrated Forecasting System.The results show that simultaneous optimisation of O(20) parameters is possible with O(100) algorithm steps using an ensemble of O(20) members, and that the optimised parameters lead to substantial enhancement of predictive skill. The enhanced predictive skill can be attributed to reduced biases in low-level winds and upper-tropospheric humidity in the optimised model. We find that the optimisation process is dependent on the starting values of the parameters that are optimised (starting from better suited values results in a better model). The results also show that the applicability of the tuned parameter values across different model resolutions is somewhat questionable since the model biases seem to be resolution-specific. Moreover, our optimisation algorithm tends to treat the parameter covariances poorly limiting its ability to converge to the global optimum.
Imaging the Earth's Upper Mantle: Markov Chain Monte Carlo Joint Inversion of Geophysical Multi-observables
Authors: Abdulghafur Fatimah , Hansen Steven , Afonso Juan Carlos
Published: February 2023

Seismic data from several long-running broadband sensors around the globe will be used to investigate the statistical significance and geologic interpretation of negative velocity discontinuities in the upper-most mantle. Several previous studies have identified negative polarity arrivals in S-wave receiver function data which are variously interpreted as lithosphere-asthenosphere and/or mid-lithosphere boundaries.One-dimensional joint-inversion is applied using the LitMod framework, which is a Bayesian statistical method driven by a Markov Chain Mote Carlo algorithm.LitMod uses a thermodynamically consistent physical model of the mantle and thus provides important constraints for the interpretation of the receiver function results.Joint inversions combine Rayleigh wave phase velocity measurements, both P and S-wave receiver functions, absolute elevation, and geoid height.Particular attention is given to the calculation and inversion of S-wave receiver function data, which represents a new addition to the LitMod framework. 
Ocean response to reduced Arctic sea ice in PAMIP simulations.
Authors: Chatterjee Sourav , Selivanova Julia , Semmler Tido , Screen James A.
Published: February 2023

Arctic Amplification (AA) – the greater warming of the Arctic than the global average - is a prominent feature of past and projected future climate change. AA exists due to multiple positive feedbacks involving complex interactions among different components of Arctic atmosphere, ocean, and cryosphere. The loss of sea ice is a key driver of AA. Sea ice loss and resultant AA can influence the global climate system, way beyond the Arctic. The atmospheric response to sea ice loss has been studied extensively. In comparison, the oceanic response has received less attention and our understanding of it is imprecise. Here, we utilize the fully coupled model simulations from the Polar Amplification Model Comparison Project (PAMIP) to explore the oceanic response to projected Arctic sea ice loss at 2o C global warming.The sea surface warming signal is maximum in the Barents-Kara Sea region in all three models analysed. Results suggest that the observed northward propagation of the Arctic ‘cooling machine’ (region of intensive heat loss to the atmosphere) is largely driven by the reduced sea ice over the northern Barents Sea. Simultaneously, the atmospheric response with stronger south-westerlies over the Norwegian Seas and southern Barents Sea reduces the heat loss therein. This may partly explain the bipolar spatial structure of heat loss in the Norwegian seas and the Northern Barents-Kara Sea. This seesaw heat loss pattern can result in a warmer inflow of Atlantic Waters from the Norwegian Sea to the northern Barents Sea as projected by CMIP6 models. The mixed layer depth response in these regions is consistent with the heat loss patterns, with a deepening of the mixed layer in regions of enhanced heat loss and vice versa. The surface ocean dynamic response is most prominent in the Beaufort Sea. With reduced sea ice, the Beaufort gyre circulation is strengthened due to larger wind forcing and accumulates freshwater within. As a result, surface salinity response shows maximum freshening in this region. In summary, preliminary results from the coupled simulations under the PAMIP protocol indicate that the observed and projected changes in the Arctic Ocean during the 21st century are strongly driven by the reduction in sea ice.
Compound Vulnerabilities in an Urban Setting: Impact of Floods on the Transportation Network in Istanbul
Authors: Daloglu Cetinkaya Irem , Pala Özge Naz
Published: February 2023

Urban areas, the core of socio-economic activity with high population density, are considered highly vulnerable to flood hazards. Istanbul, Turkey's most populated city with around 16 million inhabitants, and at the same time commercial, cultural, and social capital, was chosen as the study area. Istanbul is a metropolis that has grown under unplanned growth, particularly with rural to urban migration in the 1950s. A significant portion of the city's natural areas, stream basins and valleys have been replaced by concrete surfaces. This transformation not only brought societal challenges, but increased urban vulnerability to extreme events and hazards. As a coastal city that consists of two peninsulas, Istanbul is highly prone to flash floods from heavy rainfalls. Flood events intensely impair the municipal services (e.g., public transportation, water and sanitation, electricity distribution), consequently affect the operation of businesses and public services, and cause high economic losses as well as even deaths and casualties. Many of the highly vulnerable zones for floods already endure inadequate housing and transport access. This study aims to build a flood vulnerability index to identify the districts vulnerable to floods in the metropolitan area and assess the impacts of floods on households and transportation infrastructure. The developed vulnerability index incorporates socioeconomic and physical vulnerability components, while also closely examining key transportation infrastructure in highly vulnerable locations. Using the multi-criteria decision making approach, 9 different indicators of flood vulnerability were evaluated, then weighted by stakeholders and experts using the Analytical Hierarchy Process (AHP) method. This methodology is implemented to 100 year flood zones and 500 year flood zones to represent the potential impact of future climate change. The proposed assessment disclosed that 22% of the basin has low urban flood vulnerability while the extremely vulnerable and vulnerable zones together constituted approximately 40% of the total area.  Approximately 75% of the road length (i.e., highways, main arteries, boulevards) and 20% of the public transportation lines (i.e., stations, railways, bus lines) across the basin are located in the vulnerable areas. The findings of the study have the potential to provide policymakers with up-to-date and detailed flood vulnerability assessments to serve as the foundation for their decision-making processes under flooding hazards.
Sub-Continental Lithospheric Mantle Discontinuities beneath the Eastern Himalayan Plate Boundary System, NE India
Authors: Chaudhury Jashodhara , Mitra Supriyo
Published: February 2023

We use P-wave receiver function (P-RF) analysis and joint inversion with Rayleigh wave group velocity dispersion data to model the shear-wave velocity (Vs) structure of sub-continental lithospheric mantle (SCLM) discontinuities beneath northeast (NE) India. The most prominent SCLM discontinuity is the Hales Discontinuity (H-D) observed beneath the Eastern Himalayan Foreland Basin (Brahmaputra Valley) and Shillong Plateau. The P-to-SV converted phase from the H-D (Phs) is a positive amplitude arrival at ∼10–12 s and has positive move out with increasing ray-parameter. From joint inversion, the H-D is modeled at a depth range of 90–106 km, with 9–12% Vs increase beneath the Brahmaputra Valley. Beneath the Shillong Plateau the H-D is at a depth range of 86–102 km, with 6–9% Vs increase. An intra-lithospheric discontinuity (ILD) has been identified in the Shillong Plateau station P-RFs, as a positive amplitude PILDs phase, arriving at 8–8.5 s. This is modeled at a depth range of 65–75 km with Vs increase of ∼7±4%. We construct 2D profiles of depth-migrated common conversion-point stack of P-RFs to distinguish the SCLM discontinuity arrivals from crustal phases. 3D spline-interpolated surface of the H-D has been constructed to visualize its lateral variations. We use xenolith data from the Dharwar Craton, which has similar geological age, petrology and seismic structure as the Shillong Plateau, to petrologically model the SCLM H-D and ILD Vs structure in NE-India. From the calculated Vs structure we conjecture that the H-D is a petrological boundary between mantle peridotite and kyanite-eclogite, with its origin as metamorphosed paleo-subducted oceanic-slab, similar to other global observations. We further speculate that the shallower ILD could be formed as a contact between frozen asthenosphere-derived metasomatic melts within the SCLM.
Encroaching Mongolian oak aggravates nitrogen limitation in southern Asian boreal forest
Authors: Tang Yang , Du Enzai
Published: February 2023

Mitigation of temperate broadleaved trees into southern boreal forest has occurred in response to rapid climatic warming, consequently resulting in profound changes in species composition and ecosystem functions of southern boreal forest. However, the biogeochemical effect of migrating temperate trees on boreal forest trees remains poorly understood. Here we performed a 52-sites survey along the temperate-boreal forest ecotones in Northeastern China to uncover that the encroaching Mongolian oak, dominant trees in temperate forest, has affected N nutrition of Dahurian larch, the dominant trees of regional boreal forest. Specifically, we tested following hypotheses: (i) encroaching Mongolian oak affects N availability for Dahurian larch via modifying soil N availability; (ii) Mongolian oak directly affects N dynamic of Dahurian larch via competing for available N against Dahurian larch. Our results show that the foliar 15N is significantly lower in Mongolian oak than in co-occurring Dahurian larch. Soil 15N is negatively correlated with soil C:N ratio and stand slope but is not affected by the encroachment of Mongolian oak. Both foliar 15N abundance and difference (δ15Nfoliage-δ15Nsoil) of Dahurian larch are significantly affected by the dominance of Mongolian oak, suggesting that encroaching Mongolian oak aggravates N limitation of boreal Dahurian larch. Our findings highlight an unexpected biogeochemical effect of migrating temperate trees on boreal forest.
Extreme rainfall reduces one-twelfth of China’s rice yield
Authors: Jian Yiwei , Fu Jin , Wang Xuhui , Zhou Feng
Published: February 2023

Extreme climate events constitute a major risk to global food production. Among these, the extreme rainfall is often dismissed from historical analyses and future projections, whose impacts and mechanisms remain poorly understood. Here, we find that rice yield reductions due to extreme rainfall in China were comparable to those induced by extreme heat over the last two decades, reaching 7.6 ± 0.9% (one standard error) according to nationwide observations and 8.1 ± 1.1% according to the crop model incorporating the mechanisms revealed from manipulative experiments. Extreme rainfall reduces rice yield mainly by limiting nitrogen availability for tillering that lowers per-area effective panicles and by exerting physical disturbance on pollination that declines per-panicle filled grains. Considering these mechanisms, we projected ~8% additional yield reduction due to extreme rainfall under warmer climate by the end of the century. These findings demonstrate the critical importance to account for extreme rainfall in food security assessments, posing greater challenges to climate change adaptation.
Towards Temporal Scaling Laws for the Risk Analysis of Rare Flood Events
Authors: Bhargav Kumar Kanneganti , P Mujumdar Pradeep
Published: February 2023

Extreme flood events are rare but catastrophic and have tremendous adverse impacts on human lives and the economy. The frequency and magnitude of such events have increased globally and are likely to worsen in the future. Traditional flood risk methods estimate the extreme quantiles based on the assumption that historical data recorded at gauge stations contain a spectrum of extreme flood magnitudes. However, the available gauge station record lengths are small for several gauge stations, and these records are less likely to capture the full range of likely flood magnitudes. Hence, it is necessary to develop methods to extrapolate better the dynamics of large and rare events from historical data containing only small but frequent fluctuations. This study aims to use the scaling relation of return intervals, which is invariant for various thresholds in long-term correlated historical records and accurately estimate the risk associated with rare events. The analysis is carried out on 212 daily streamflow series across the major river basins in peninsular India. Persistence in the streamflow series is examined by estimating the Hurst coefficient with a Detrended Fluctuation Analysis. Return level distribution parameters are then estimated using the analytic equations between parameters and the Hurst coefficient. The threshold-invariant scaling of the probability of return intervals and the ratio of return levels to mean return levels allows the formulation of hazard functions, which are, in turn, used to estimate the risk of rare events. This work provides an approach for obtaining flood event sets that may contain  a wider range of magnitudes than present in the historical data. The present study contributes towards improving the at-site frequency analysis of floods using the temporal scaling law of return levels. Simultaneous occurrence of different extremes may alter the return levels of rare events such as, for example, flooding in coastal areas caused by the compound effect of storm surge and streamflow. This work can be extended to understand the effect of long-term memory and the cross-correlation of causal factors on risk estimation of compound extremes.
Selecting the best brachiopod biomineral archive of the Wuchiapingian climate change
Authors: Viaretti Marco , Crippa Gaia , Angiolini Lucia
Published: February 2023

The Late Permian was a time interval characterized by extreme environmental perturbations, culminating with the Siberian Traps-related gas emissions and the subsequent global warming and ocean acidification, which produced the most severe mass extinction of the Phanerozoic (Dal Corso et al., 2022). Evidence of these perturbations are recorded in fossil archives, as pristine brachiopod shells (Garbelli et al., 2017). Here, we show shell microstructural variations and stable isotopes profiles recorded by specimens of Araxilevis intermedius (Abich, 1878), a large-sized and thick-shelled brachiopod species abundant in the Upper Permian of Iran. Nine specimens of A. intermedius were selected from several Wuchiapingian beds of the Hambast Formation in the Abadeh Section and of the Julfa Formation in the Ali Bashi Mountains Main Valley section (Iran), following the correlation by Viaretti et al. (2021). Prior to the isotope analysis different screening tests were performed on the brachiopod shells from both sections: Scanning Electron Microscope microstructural analysis, cathodoluminescence (CL) and trace elements analyses. Specimens of A. intermedius are characterized by a three-layered shell, comprising a secondary layer of cross-bladed laminae and a tertiary columnar layer; the primary layer is not preserved. The specimens from the Hambast Formation of Abadeh show a partially altered shell, whereas those from the Julfa Formation of the Ali Bashi Mountains show a well-preserved microstructure, despite CL analysis indicating that all the specimens were non-luminescent, both the microstructurally well-preserved and the altered ones. After having checked the shell preservation, 12 to 29 powder samples were collected from the longitudinal shell section of each pristine specimen of A. intermedius using a sclerochronological approach. This method allowed to investigate the seasonal environmental changes recorded by the brachiopod shells of A. intermedius from Iran and to test if this species of the Class Strophomenata, abundant in this time interval also outside Iran, can be considered a good archive for paleoclimatic and paleoenvironmental reconstructions in the Late Permian. Dal Corso J., Song H., Callegaro S., Chu D., Sun Y., Hilton J., Grasby S.E., Joachimski M.M. & Wignall P.B. 2022. Environmental crises at the Permian–Triassic mass extinction. Nat. Rev. Earth Environ, 3, 197-214.Garbelli C., Angiolini L. & Shen S.Z. 2017. Biomineralization and global change: A new perspective for understanding the end-Permian extinction. Geology, 45(1), 19-22.Viaretti M., Crippa G., Posenato R., Shen, S.Z. & Angiolini L. 2021. Lopingian brachiopods from the Abadeh section (Central Iran) and their biostratigraphic implications. Boll. Soc. Paleont. It., 60(3), 213-254.
Introducing DL-GLOBWB: a deep-learning surrogate of a process-based global hydrological model
Authors: Droppers Bram , Leijnse Myrthe , Bierkens Marc F.P. , Wanders Niko
Published: February 2023

Process-based global hydrological models are an important tool for sustainable development and policy making in today’s water-scarce world. These models are able to inform national to regional scale water management with basin-scale accounting of water availability and demand and project the impacts of climate change and adaptation on water resources. However, the increasing need for better and higher resolution hydrological information is proving difficult for these state-of-the-art process-based models as the associated computational requirements are significant.Recently, the deep-learning community has shown that neural networks (in particular the LSTM network) can provide hydrological information with an accuracy that rivals, if not exceeds, that of process-based hydrological models. Although the training of these neural networks takes time, prediction is fast compared to process-based simulations. Nevertheless, training is mostly done on historical observations and thus projections under climate change and adaptation are uncertain.Inspired by the complementary strengths and weaknesses of the process-based and deep-learning approaches, we present DL-GLOBWB: a deep-learning surrogate of the state-of-the-art PCR-GLOBWB global hydrological model. DL-GLOBWB predicts all water-balance components from the process-based model, including human water demand and abstraction, with a nRSME of 0.05 (range between 0.0001 and 0.32). The DL-GLOBWB surrogate is orders of magnitudes faster than its process-based counterpart, especially as surrogates trained at low resolutions (e.g. 30 arc-minute) can effectively be downscaled to higher resolutions (e.g. 5 arc-minute).In addition to introducing DL-GLOBWB, our presentation will explore future applications of this deep-learning surrogate, such as (1) improving model calibration and performance by comparing DL-GLOBWB outputs with ins-situ data and satellite observations; (2) training DL-GLOBWB on  future model projections to include global change; and (3) the implementation of DL-GLOBWB to dynamically, and at high resolution, visualize the impact of climate change and adaptation to stakeholders.
Assessment of thermal analysis techniques for determining organic, black, and inorganic carbon contents in urban soils
Authors: Hyun Junge , Bae Jeehwan , Yoo Gayoung
Published: February 2023

Although urban greenery is an important area for soil carbon (C) sequestration in national and international policies, there is a lack of studies on its unique soil C status. Especially the contribution of black carbon (BC) and inorganic carbon (IC), which originated from anthropogenic activities, need to be separated from ecosystem-driven organic carbon (OCeco) to accurately quantify the soil C sequestration in urban ecosystems. However, there is currently no standardized, widely used method to separate various forms of C in this soil. In this study, we suggested a robust and reliable method to discriminate the OCeco, BC, and IC contents and understand the anthropogenic effects on C in urban soils. To achieve this objective, we tested the accuracy of the “EGA with peak deconvolution approach” that derives a CO2 thermogram from an evolved CO2 gas analyzer (EGA) connected to a thermal analyzer and conducts sample-by-sample peak deconvolution. Since we used the model mixtures that had known OCeco, BC, and IC contents, the absolute accuracy of this approach could be tested. As a result, EGA with peak deconvolution approach showed high accuracy (R2 > 0.90), and the regression lines between the known and measured values were close to the 1:1 line.Using the EGA with peak deconvolution approach, we further investigated the soils in urban greeneries. EGA with peak deconvolution approach was helpful in understanding the impacts of human intervention on the soil C cycle. Surrounding land use significantly altered the soil OCeco/TC and BC/TC but was not soil IC/TC; the OCeco/TC tended to increase with green area, while the BC/TC had a positive relationship with impervious area. The suggested method can be used to evaluate the C sequestration rate of SSM practices in the urban area. Without the information on OCeco and BC, the impacts of human intervention on soil C can be misinterpreted, which overestimates the C sequestration rate.
Coupled Poro-elasto-plastic models of transient fluid flow in response to a crustal strike-slip fault : insight from a geothermal setting in the South Andean volcanic zone
Authors: Gerbault Muriel , Saez Felipe , Ruz Ginouvez Javiera , Iturrieta Pablo , Hurtado Daniel , Cembrano José
Published: February 2023

Geothermal systems are recognized as key energy resources as well as locations where hydrothermally enhanced chemical reactions can favour mineralizations of economic interest. While fluid-fault interactions in the upper crust have received a wealth of investigations using observational, experimental and modelling approaches, the multi-parametric processes at play are still poorly constrained. While faults can alter fluid flow in their surroundings, potentially acting as barriers or conduits for fluids, magmatic and hydrothermal fluids can also modify pore pressure and alter faults resistance to slip motion. The Planchon-Peteroa geothermal system of the South Andean Volcanic Zone (Chile), illustrates at tectonic crustal scale, how strike-slip faults appear closely involved in the localization of hydrothermal fluid flow. Here, we carry a preliminary modelling approach to be considered as a proof of concept, to show how within such a tectonic setting, a strike slip fault influences fluid flow out from a geothermal reservoir. We developed an original poro-elasto-plastic Finite Element Method (FEM) based on the FEniCS library, and in which the poro-elastic and the elasto-plastic constitutive equations are implicitly coupled. Once this implementation is benchmarked, we assess the development of fluid flow due to a slipping vertical strike-slip left-lateral fault set at 5 km depth. The development of dilational and contractional domains in the fault’ surroundings lead to mean stresses and volumetric strains that range between ±1 MPa and ±10−4, respectively. The appearance of negative and positive fluid pressure in these domains lead to a time-dependent focused fluid flow, which resembles the suction-pump mechanism proposed ca. 30 years ago. We investigate the spatial and temporal evolution of this fluid flow when varying fault permeability, shear modulus, fluid viscosity, and rock frictional strength. We report a maximum fluid flux reaching 8 to 70 times the initial stationary flux. Pressure-driven fluid diffusion returns to stationary state between weeks to months after fault slip. We also show how a plasticity criterion as simple as the von Mises criterion already enhances fluid flow, locally. This transient process highlights the importance of addressing such solid-fluid coupling in studies aiming at constraining volcanic eruption triggers as well as seismic fault destabilization, and the means and pros of geothermal system development.
A Study on the Identification of Explosions, Collapses and Earthquakes using KMA Seismic and Infrasound Networks
Authors: Min Kyungmin , Choi Mikyung , You Seolhan , Choi Yeongjae , Chai Gyeongdon , Park Suncheon
Published: February 2023

The Korea Meteorological Administration(KMA) uses seismic and infrasound networks data identifying  explosion, collapse, and earthquakes.We identify events using various methods . First, Vp/Vs spectral amplitude ratio in the frequency domain is calculated by applying Fast Fourier Transform (FFT) and Power Spectrum Density (PSD) analysis methods. The Vp/Vs ratio more than 50% is distinguished as an explosion.Second, Explosion, collapse, and earthquakes are distinguished by (using) the body wave method (Walter et al., 2018). The Pn/Lg, Lg/Lg ratios are used for studying the DPRK 6th test, collapse and induced earthquakes at Chuncheon, Sokcho, and Seohwa KMA seismic networks.Finally, the KMA operates five infrasound networks for  monitoring DPRK nuclear test and Mt. Baekdu volcano in addition to the seismic networks.Infrasound analysis calculates the apparent speed and azimuth of the infrasound source by applying Progressive Multi-Channel Correlation(PMCC)  algorithm.The calculated azimuth and apparent velocity are  important factors in determining that the seismic and infrasound signals occurred at the same point during an explosion.
GPU-HADVPPM: high-efficient parallel GPU design of the Piecewise Parabolic Method (PPM) for horizontal advection in air quality model (CAMx)
Authors: Cao Kai , Wu Qizhong
Published: February 2023

With semiconductor technology gradually approaching its physical and thermal limits, Graphics processing units (GPUs) are becoming an attractive solution in many scientific applications due to their high performance. This paper presents an application of GPU accelerators in air quality model. We endeavor to demonstrate an approach that runs a PPM solver of horizontal advection (HADVPPM) for air quality model CAMx on GPU clusters. Specifically, we first convert the HADVPPM from its original Fortran form to a new Compute Unified Device Architecture C (CUDA C) code to make it computable on the GPU (GPU-HADVPPM). Then, a series of optimization measures are taken, including reducing the CPU-GPU communication frequency, increasing the size of data computation on GPU, and optimizing the GPU memory access order to improve the overall computing performance of CAMx. Finally, a heterogeneous, hybrid programming paradigm (MPI+CUDA) is presented and utilized with the GPU-HADVPPM on GPU clusters. When the consistency of its results is verified, offline experiment results show that running GPU-HADVPPM on one K40 and V100 GPU can achieve up to 845.4x and 1113.6x acceleration. By implementing a series of optimization schemes, the CAMx model coupled with GPU-HADVPPM resulted in a 12.7x and 94.8x improvement in computational efficiency using a GPU accelerator card on a K40 and V100 cluster, respectively. The multi-GPU acceleration algorithm enables 3.9x speedup with 8 CPU cores and 8 GPU accelerators on V100 cluster. Figure 1. The calling and computation process of the HADVPPM function on the CPU-GPU.Figure 2. (a) The offline performance of the HADVPPM scheme on CPU and GPU. The unit of the wall times for the offline performance experiments is millisecond(ms); (b) The total elapsed time of CAMx-CUDA V1.3 on multiple GPUs. The unit of elapsed time for experiments is seconds (s). The orange bar indicates the elapsed time of CAMx on the CPU, the blue bar shows the elapsed time on the CPU-GPU heterogeneous platform, and the red line indicates its speedup ratio on the heterogeneous platform.
Variation of dissolved phosphorus in groundwater of riparian zones in an agricultural area
Authors: Koh Dong-Chan , Kwon Hong-Il
Published: February 2023

Phosphorus, which is one of important factors of surface water eutrophication, has been the main issue in surface water quality management. In recent years, there has been an increasing interest in phosphorus in groundwater as well as surface water. Increasing number of studies has reported groundwater with high concentrations of phosphorus and its effect on adjacent surface water. The multi-level monitoring wells were installed in riparian zones of an agricultural area to demonstrate processes of phosphorus in groundwater. A stream in the area is largely in gaining condition, but losing condition was found in the area with extensive groundwater pumping. In this study, the processes of increasing and decreasing phosphorus concentration in groundwater under anaerobic conditions were examined with redox sensitive species. The dominant redox processes in groundwater were identified using redox sensitive parameters, which varied from oxic to sulfate reduction. Phosphorus concentrations were low in oxic and denitrification dominant condition and high in iron reducing dominant condition. This result was consistent with many recent studies. It is expected that phosphorus concentrations were reduced by precipitation of secondary iron minerals in the aerobic condition and increased by dissolution of the secondary minerals in the anaerobic condition. However, phosphorus concentration in the groundwater tended to attenuate under the more reducing condition than iron-reducing dominant condition. In this study, we tried to interpret dissolved phosphorus concentration in relation to the redox sensitive species and to understand the attenuation processes of dissolved phosphorus under strongly reducing conditions.
Low-cost sensor observations for flash flood and landslide early warning systems in the mountainous area
Authors: Methaprayun Monton , Jotisankasa Apiniti , Khunwisetkul Ratchanon , Bogaard Thom , Mapiam Punpim Puttaraksa
Published: February 2023

Flash floods and landslides are severe natural hazards caused by heavy rainfall, which frequently occur in mountainous areas in most countries worldwide. Hydrometeorological measuring networks are key to tracking heavy storms and quantifying hydrological behaviour. Unfortunately, the monitoring networks in these regions are often scarce due to various challenges such as inaccessibility, limited power and data transmission capabilities, and maintenance requirements. To address these challenges, our research aims to develop and deploy low-cost sensors in the Khao Yai National Park, Lamtakong basin, northeastern Thailand, which are linked to high-resolution radar rainfall observations. This is subsequently used in spatially distributed models that are the basis of an early warning systems that is under development in this hazard-prone mountainous region. These sensors measure various physical parameters, including soil moisture, precipitation, water and air pressure, and transmit real-time data via NB-IoT mobile signals, with backup storage in SD cards. The stations were designed to be simple to maintain, with materials that were readily accessible. All collected data will be transmitted in real-time at high temporal resolutions. First, the rain gauge rainfall data will be merged with weather radar data to compute radar rainfall bias adjustment for preparing high-quality gridded rainfall over the study area. After that, the adjusted radar rainfall product combined with the hydrological measurements will be used as input for spatially distributed physical-based flash floods and landslides modelling. The use of low-cost sensors allows the monitoring network to be more widely deployed, particularly in areas that are difficult to access like the natural park. Furthermore, increasing coverage and denser data collection will lead to more accurate monitoring of the highly heterogeneous rainfall patterns and thus short-term rainfall forecasting. This will lead to a more effective early warning system.
Filling N2O data gaps during the last 800,000 years via Artificial Intelligence Techniques
Authors: Salehnia Nasrin , Ahn Jinho
Published: February 2023

One of the primary proxies for ancient atmospheric air compositions is the fossil air occluded in polar ice sheets. Ice cores are significant archives for the atmospheric Greenhouse Gas (GHG) concentrations during the last 800 kyr (thousand years). GHG records from polar ice cores have provided valuable information on past climatic, atmospheric, and glaciological changes. For example, nitrous oxide (N2O) is a long-lived GHG and gives us information on nitrogen cycles. However, the time resolution and missing gaps of N2O records limit our understanding of the control mechanisms in the atmosphere. One of the well-known state-of-the-art methods is AI (Artificial Intelligence) techniques, and its main branch is ML (Machine Learning) method. To fill the N2O gaps during the last 800 kyr, we used CO2 and CH4 concentration data from Antarctic ice cores (Vostok and EPICA Dome C ice cores). The ML methods were run in two steps. First, the gap parts were deleted from the time series, and modeling was performed with CO2 and CH4 concentration data with six various ML methods (Linear, Support Vector Machine, Tree, Gaussian Process Regression (GPR), Artificial Neural Network (ANN), and Ensemble). Then, the best model was selected for the second step to reconstruct the N2O in the data gaps. Although other AI methods revealed acceptable results in the first step, the GPR method produced a high-quality simulation with R2= 0.86, RMSE= 7.38 ppb, and MAE= 4.15 ppb. Finally, the simulation for the N2O gaps was performed with the GPR method. Our results confirm that AI techniques have a high potential to produce continuous paleo atmospheric GHG concentrations. Future research includes modeling with other AI and ML methods and applying the AI techniques to other ice core records, such as water isotope ratios (temperature proxy) over various past periods.
Is mixed brittle-ductile deformation simultaneous or successive? Insights from the strontium isotope systematics of deformation structures in a heterogenous fault zone
Authors: von Hagke Christoph , Dielforder Armin , Glodny Johannes , Morley Chris K.
Published: February 2023

Modern concepts of fault strength account for compositional and hence rheological heterogeneity of natural fault zones. An important implication of heterogeneity is strain partitioning between stronger and weaker phases and a gradual transition from brittle to ductile deformation. While a broader brittle-ductile transition zone is consistent with deformation fabrics in fault zones, it remains uncertain how broad the transition zone is and whether deformation fabrics record truly simultaneous brittle-ductile deformation or successions of brittle and ductile deformation driven by temporal changes in temperature, strain rate, and/or pore fluid pressure. Here we present data from a major fault zone of the Permo-Triassic Khao-Khwang fold-and-thrust belt, Thailand. The fault zone is located in marine calcareous shales with Permian limestones in the foot- and hanging wall. Thrusting occurred at peak temperatures of ~200°C. Deformation fabrics document frictional sliding, cataclasis, mineral veining, and pressure solution in the main fault zone and local mylonitization at the base of the hanging wall limestone. Thus, the fault zone records competing brittle and ductile deformation and incipient strain partitioning between the shales and limestones, consistent with a broad brittle-ductile transition zones due to rheological heterogeneity. Radiogenic strontium isotope ratios (87Sr/86Sr) of syntectonic vein carbonates and calc-mylonites, tell, however, a slightly different story. Vein carbonates from the fault zone all have Permian seawater-like 87Sr/86Sr ratios documenting a rock-buffered pore fluid during brittle deformation. By comparison, the calc-mylonites record less radiogenic 87Sr/86Sr ratios hinting at a mantle source. The Sr ratios are similar to those of syntectonic mafic dykes that intruded Khao-Khwang fold-and-thrust belt. We interpret the distinct Sr ratios of the calc-mylonite to document that mylonitization was triggered by migration of hot magmatic fluids. In this case, strain partitioning between the shales and limestone were likely insignificant without the impact of the hot fluids, although the limestones were already close to the brittle-ductile transition at ambient temperatures of ~200°C. Taken together, our findings suggest that the transition from frictional deformation and pressure solution in shales to ductile shearing in limestones might be rather abrupt than gradual.
Atmospheric dynamic constraints on freshwater sourced from the Tibetan Plateau under Paris climate pledges
Authors: Zhao Yutong , Wang Tao , Xu Chaoyi
Published: February 2023

Almost one-fifth of the world’s population relies on rivers originating from the Himalayas and Tibetan Plateau. How global warming will impact runoff change in this water tower of Asia has attracted worldwide attention. Yet, their picture under Paris climate pledges is still a montage due to “very low” confidence in future precipitation changes. we introduce an atmospheric dynamic framework to constrain future precipitation changes from climate models by the end of this century. We then constrain runoff changes from scaling laws from precipitation and evapotranspiration and glacier melt contributions. The outcome is a smaller increase of precipitation by about a factor of two, and the net increase of June-to-September runoff is estimated to increase by 3.1% to 6.8% for global warming levels comprised between 1.5 and 4°C. Although ubiquitous increase in upstream runoff is found across basins, the water scarcity conditions alleviated in Yangtze and Yellow basins and degraded in the Indus and Ganges basins. These important findings highlight that the practical water scarcity adaptation measures should be searched in Pakistan and India to secure future food security and environmental sustainability.
Addressing forest canopy decoupling on a global scale
Authors: Jocher Georg
Published: February 2023

The eddy covariance (EC) method, nowadays the standard method for determining forest ecosystem-atmosphere turbulent exchange, faces a major threat in its application: the air masses below the canopy are regularly decoupled from the air masses above the canopy. Consequently, the EC measurements above the canopy like e.g. H2O and particularly CO2 fluxes can be biased due to missing signals from below-canopy processes. This decoupling is strongly site dependent and influenced by meteorological conditions, canopy properties and tower-surrounding topography. It can be verified and addressed by subsequent EC measurements below and above the canopy. Specifically, the correlation of σw below and above the canopy gives information about the coupling state as this correlation is linear during periods of full coupling.The current study aims to address the decoupling issue on a global scale. For this purpose, approximately 30 forest sites from around the world will be analyzed in a standard way with regards to decoupling. The study sites cover manifold vegetation types and climate zones, all sites are equipped with concurrent below and above canopy EC measurements. Preliminary results highlight the dependence of decoupling on meteorological conditions, canopy properties and tower surrounding topography. Nevertheless, the final goal of this action is to derive global relations between these influence factors and decoupling which will be applicable in a general way on each forest site worldwide. Highest quality turbulent fluxes will be the outcome and the accuracy of EC derived forest water and carbon budgets will improve.
Wetland inflow simulation using artificial intelligence prediction model based on classification for water surface area identification
Authors: Seo Jiyu , Won Jeongeun , Lee Chaelim , Kim Sangdan
Published: February 2023

Wetland ecosystems have complex interactions of physical and biogeochemical processes, but the first step toward restoring the health of wetland ecosystems is an accurate understanding of the water cycle in wetland ecosystems. In addition, a quantitative understanding of the wetland water cycle is essential to utilize wetlands in regional water balance and ecosystem conservation. However, observational data essential for understanding the wetland water cycle are difficult to obtain through field measurements or are difficult to observe due to cost issues. Therefore, this study proposes a procedure for estimating wetland inflow using Sentinel-2 satellite data. To this end, a classification-based artificial intelligence model using data from major multi-purpose dams located on the Nakdong River in the southeastern part of the Korean Peninsula is designed. Input data for artificial intelligence learning is created by the following procedure. 1) Derivation of the water level-water surface area relationship curve using the water level-water volume relationship of the multi-purpose dam. 2) Using the water level-water surface area relationship curve and DEM, derive an identifier that distinguishes water and land areas. 3) Design a random forest model that compares Sentinel-2 satellite information and water-land identifiers. 4) Derivation of identifiers that can identify water and land in unmeasured wetland areas from water-land information of satellite information. By combining the water surface area of the wetland estimated through this process and the DEM of the wetland area, the wetland water level-water surface area-water volume relationship curve is calculated, and finally the wetland inflow is simulated. The simulated wetland inflow can be used to estimate the parameters of various hydrologic models, and it is expected that the understanding of the wetland water cycle can be improved by using the verified hydrological model. 
Acknowledgement
This work was supported by Korea Environmental Industry&Technology Institute (KEITI) through Wetland Ecosystem Value Evaluation and Carbon Absorption Value Promotion Technology Development Project, funded by Korea Ministry of Environment (MOE). (2022003640001)
 
Investigation Effects of Environmental and Geographical Factors on Thermal Environment in Aging Rural Areas in Taiwan
Authors: Wang Tzu-Ya , Juang Jehn-Yih
Published: February 2023

In the recent years, under the influence of land cover changes and climate changes, more frequent extreme heat events have occurred and make people face severer heat stress than before, especially for the people of low socioeconomic status, elderly or other vulnerable groups. Moreover, although land cover changes in rural areas are milder than in urban areas, the rotation of crop fields and expansion of non-vegetation areas in rural areas will alter the landscape and further influence the thermal environment. However, the issues of thermal comfortability in aging rural areas have been rarely studied compared to the urban areas in the past. To quantify and mitigate the risk of heat exposure of the elderly in rural areas, the goal of this study is to analyze the spatial-temporal characteristics of thermal environment and heat-related comfortability in an aging rural areas, Yunlin County, in central Taiwan.To characterize the spatial-temporal patterns of the thermal environment in Yunlin, this study estimated the spatial distribution of different meteorological parameters from seasonal to annual scales and analyzed the land cover compositions from the satellite remote-sensing images. Furthermore, to evaluate the effects of heat stress on the human comfort in aging rural areas, a thermal comfort index, physiological equivalent temperature (PET), was quantified using the meteorological data from weather stations in Yunlin and surrounding area with the Python package of pythermalcomfort. In addition, the statistical methods will be used to analyze how land use affects the microclimate and comfort in the Yunlin area from the community to regional scales. In brief, the anticipated results from this study are expected to characterize factors that affect the thermal environment in aging rural areas, and further provide management and policy suggestions for the reduction in the risk of heat exposure in the future.Key words: Thermal comfortability, Physiologically Equivalent Temperature (PET), Heat stress, Elderly group 