bluuebunny/crossref_metadata_2025 huggingface dataset:
Intra-crustal mantle underneath the Himalayan-Tibetan range
Authors: Sternai Pietro
Published: February 2023

The majestic Himalayan-Tibetan mountains raised due to doubling of the continental crust during the India-Asia collision, which is commonly assumed to occur by under-thrusting of the Indian crust directly below the Asian crust. However, this model implies rheologically weak subducting and upper plate lithospheres and, thus, a collision system that is unable to support a high plateau and whose deformation style is inconsistent with the gross structural and metamorphic architecture of the Himalayan-Tibetan system. Numerical models show that collision between relatively stiffer plates generates strain and metamorphic structures as well as elevations more similar to those observed, but crustal doubling occurs by stacking the subducting crust underneath the rigid upper plate mantle lithosphere. A marked mantellic signature in fluids outflowing the suture zone, the geochemistry of south Tibetan mantle xenoliths, and long wavelength buckling of the Tibetan lithosphere further support the presence of intra-crustal mantle between the Indian and Asian continental crusts. Reconciling the available geophysical evidence with this new model of crustal doubling in the Himalayan-Tibetan range will entail profound implications for our understanding of mountain building during continental subduction and collision.
Discrepancies between Boundary-layer Observations and the Traditional Thermal Energy Balance
Authors: Sun Jielun
Published: February 2023

A series of discrepancies between field observations and the traditional thermal energy balance derived from the 1st law of thermodynamics are investigated. Intrigued by some historically known puzzles such as surface energy imbalance, failed potential temperature conservation, and dissimilarity between temperature and humidity, the investigation focuses on physical processes in the atmospheric boundary layer that are uniquely controlled by the diurnal variation of surface heating/cooling. Examination of temperature changes is extended to air-temperature-related variables such as turbulent heat fluxes and temperature variances. Inconsistency between field observations and the traditional thermal energy balance is found not only in their magnitudes but also in their diurnal cycles. Inability of the traditional thermal energy equation for explaining all the observations that are distinctively related to air temperature changes challenges validity of the traditional thermal energy balance theory.   The research is supported by NSF AGS-2203248.
The effects of coarse dust in the models and observations in the dust source regions
Authors: Stenchikov Georgiy , Mostamandi Suleiman , Shevchenko Ilia , Ukhov Alex
Published: February 2023

In dust source regions, such as the Middle East, dust is a major environmental factor affecting climate, air quality, and human health. Dust also hampers solar energy harvesting by weakening downward solar flux and depositing on optically active surfaces of solar energy devices. In this study, we combine fine-resolution WRF-Chem simulations with size-segregated measurements of dust deposition to quantify the contribution of coarse (2.5 um < r < 10 um) and giant (10 um <r < 100 um) dust particles in aerosols radiative forcing and deposition rates. Most up-to-date models do not represent the particles with r > 10 um. The absence of large particles in the models does not significantly affect the radiative fluxes, as their contribution to AOD is relatively small, but they comprise the most dust-deposited mass. We found that dust deposition rates calculated in WRF-Chem and reanalysis products are 2-3 times smaller than the observed. However, the deposition rate of particulate matter with a diameter smaller than 10 um (PM10) is in good agreement between the models and observations. In the Middle East, fine dust particles are predominantly responsible for the significant reduction (> 5 %) of the downward solar flux hampering solar energy production. Still, dust-deposited mass, primarily associated with coarse particles, causes about a 2% loss of PV panel efficiency daily due to soiling. As was suggested previously, WRF-Chem, like many other models, tends to overestimate the atmospheric concentration of fine (r < 2.5 um) dust particles and underestimate the concentration of coarse particles. As seen from the comparison of the size distribution of deposited dust in simulations and observations, the latter is caused not as much by too fast deposition of large particles but due to underestimating their emission in the models. 
CHASE: a model of human migration under environmental changes
Authors: Muneepeerakul Rachata
Published: February 2023

This presentation focuses on migration of the most influential mammal species: humans! For humans, migration is one of the most drastic adaptation strategies against unfavorable conditions. This model is named after the factors it includes to capture migration probability by humans, namely CH = Changing mindset, A = Agglomeration, S = Social ties, and E = the Environment. Because many of these factors are not typically included in migration models of other non-human species, the CHASE model has the potential to give rise to different dynamics and patterns, which may in turn be useful for understanding and modeling migration of other species. Here we performed numerical experiments on the model by subjecting the human agents in the model to two different kinds of disturbances: sudden shocks and gradual changes. Preliminary results on the dynamics and patterns will be reported, compared, and discussed. Discussion with other presenters and comparison to other presentations in this session should lead to new ideas useful for modeling migration of humans and other species alike.
Upper Miocene to Present fault architecture and fluid pathways in the Val d’Agri basin (Southern Italy)
Authors: Schirripa Spagnolo Giulia , Agosta Fabrizio , Aldega Luca , Billi Andrea , Bernasconi Stefano , Prosser Giacomo , Smeraglia Luca , Carminati Eugenio
Published: February 2023

Structural analysis coupled with geochemical study of syn-tectonic mineralizations unraveled the role of fluids during the polyphase tectonic evolution of the Val D’Agri, a seismically-active intermontane basin located in the Southern Apennines fold and thrust belt, hosting the largest onshore oil field in western Europe. In this basin, the structural control on present-day fluid circulation is still not well constrained. For this reason, the aim of this work is to reconstruct the Val d’Agri fault system (VAF) architecture and paleo-fluid circulation during the basin tectonic evolution. The VAF evolution was caused by non-coaxial polyphase stress regimes that can be summarized in: 1) Upper Miocene-Lower Pliocene compressional regime; 2) Upper Pliocene-Lower Pleistocene late orogenic strike-slip regime 3) Early Pleistocene-Present post-orogenic extensional regime. Based on new field work, mapping, and structural analysis, we recognized that the VAF is organized in different oriented faults sets. The main sets are N-S-, NE-SW-, and ESE-WNW-striking faults, where the last one has the higher degree of maturity. U-Pb dating of calcite slickenfibres highlighted the long-term tectonic history of these fault sets, with episodes of activation and reactivation of inherited faults. In particular, we recognize: N-S-striking normal faults that reactivated inherited Upper Miocene-Lower Pliocene thrusts; Upper Pleistocene NE-SW-striking normal-lateral faults; one Miocene ESE-WNW-striking normal-lateral fault, with also evidence of reactivation in more recent time. Clumped isotopes analysis together with optical and cathodoluminescence observations of about 50 syn-tectonic calcite mineralizations allowed us to link specific fluid pathways to the different stress regimes. Indeed, bed-parallel veins and mineralizations sampled along transpressive, transtensive, and normal fault sets show that: 1) during the Upper Miocene-Lower Pliocene compressive tectonic phase, fluid circulation occurred in a closed system, characterized by host-rock buffered fluids; 2) during Upper Pliocene-Lower Pleistocene late orogenic phase, fluid circulation occurred in an open system, characterized by meteoric water with low to moderate residence time; 3) during the Lower Pleistocene-Present extensional phase, fluid circulation occurred in an open system, characterized by the mixing of meteoric water and uprising deep high temperature fluids. We highlight that the reconstruction of paleo to present-day fluid circulation is a valid tool for assessing natural and induced seismic hazard in seismically active areas where hydrocarbons are exploited and fluids are injected into the crust, such as in the Val d'Agri basin.
Emissions pathways change how abnormal climatic conditions de-emerge beyond net-zero
Authors: Douglas Hunter , Frame Dave , Revell Laura
Published: February 2023

As more and more countries set net-zero targets and progress is made on decarbonising industries, the prospect of achieving a net-zero (or even net-negative) emissions world is beginning to come into focus. Our current understanding, however, is that the climate will not immediately stabilise everywhere under such conditions. Understanding where and how the climate will change in a net-zero world is important for adaptation planning and goal setting. Climate change emergence techniques are useful for quantifying change relative to what people and ecosystems are accustomed to. However, to date these techniques have been little used to assess climate change at and beyond net-zero emissions. Whether or not aspects of the climate system “de-emerge” and return to within baseline variability remains under-explored. In this work, we use CMIP6 models to quantify climate change emergence in terms of signal-to-noise for annual- and seasonal-average temperature and precipitation, as well as strength and position of the eddy-driven jets.Applying this framework, we calculate the rate and extent of de-emergence that occurs when carbon dioxide concentrations fall. We first combine results from multiple models participating in the Carbon Dioxide Removal Model Intercomparison Project (CDRMIP) to establish global and regional behaviour for these variables under an idealised rising/falling CO2 scenario. We then apply the same analysis to multiple models’ results for ScenarioMIP emissions pathways with net-negative CO2 emissions (SSP1-1.9, SSP1-2.6, SSP4-3.4, and SSP5-3.4). We find that both temperature and precipitation exhibit partial reversibility on the scale of decades to centuries, albeit with significant hysteresis due to lag effects. These patterns are clearly apparent in the CDRMIP results and less so for the SSPs. There are significant regional differences in the rate and extent of de-emergence, including a strong land-sea contrast. The jet parameters, in contrast, respond quickly to greenhouse gas and other forcings, and so do not exhibit comparable hysteresis. Those models with data extending beyond 2100 allow for better quantification of de-emergence. CO2 peak concentrations and rates of change both influence the stable climate state, though disentangling these factors remains challenging.  
Desert dust as a plant fertilizer in an ambient and elevated CO2
Authors: Lokshin Anton , Palchan Daniel , Gross Avner
Published: February 2023

Desert dust, volcanic ash and fire ash are the most abundant natural atmospheric particles. These particles considered as an important nutrient source that controls the long-term productivity of infertile terrestrial ecosystems, by replenishing soil nutrient stocks. However, currently we do not know whether atmospheric deposition can act as a direct, alternative source for nutrients. These are particles enriched with phosphorus (P) and other essential macro and micronutrients such as: K, Ca, Mg, Zn, Cu, Fe, Mn, Zn, and Mo. These nutrients are vital for plants and support their growth.The current research shows that elevated CO2 (eCO2) in the atmosphere has positive and negative effects: On the positive side, increase of CO2 levels is predicted to result with an increase in photosynthesis leading to improved primary biomass production and thus enhancement of CO2 capture. On the other hand, at eCO2 plants show decreased concentrations of mineral nutrients in most of their organs, suggesting downregulation of the activity of the membrane transporters involved in root nutrient uptake; a decreased ability to assimilate nutrients from the roots system.Preliminary results of recent studies had shown that plants can utilize P via foliar nutrient uptake mechanism, directly from dust that settled on the plant’s leaves. Since the efficiency of roots to assimilate nutrients is projected to decrease in future eCO2, foliar nutrient uptake may be a significant alternative pathway for plants to gain needed nutrients. In this work, we used atmospheric fertilization experiments – where we deposited dust directly on plant leaves – to show that atmospheric deposition boosts plant growth and fertilizes them through direct foliar nutrient uptake pathway. The foliar nutrient uptake mechanism was shown both in an ambient and eCO2 levels for the three primary atmospheric particles mentioned above. We saw that volcanic ash had significantly increased biomass at eCO2 compared with ambient CO2 levels. Our results demonstrate that foliar nutrient uptake is a significant mechanism at immediate timescales. Furthermore, that the direct alternative pathway of foliage nutrients assimilation has a potential to regulate carbon sink processes in a terrestrial ecosystem in a future climate.
Paleomagnetism of Late Triassic Volcanic Rocks From the Southern Qiangtang Block, Tibet: Constrains on the Closure of the Paleo-Tethys Ocean
Authors: Wei Bitian , Cheng Xin , Domeier Mathew , Wu Hanning
Published: February 2023

To better constrain the drift history of the South Qiangtang block and the closure of the Paleo-Tethys Ocean, we report a paleomagnetic result isolated from 25 sites (199 samples) of Late Triassic volcanic rocks from the Xiaoqiebao Formation. The directions of the characteristic remanent magnetization isolated from these rocks pass both fold- and reversal tests, and are likely primary magnetizations. On base of these data, we estimate that the South Qiangtang block occupied a paleolatitude of 30.1°N±4.6 at 222Ma. When combined with existing paleomagnetic constraints, these new results indicate that the South Qiangtang block moved rapidly northward between the middle Permian and Late Triassic, at an average south‐north speed of ~13.4 cm/yr during middle Permian to Late Triassic. Our new data further suggest that the Paleo-Tethys likely closed by ~222Ma, and the north-south width of the Neo- Tethys Ocean was reached ca. 7000 km at this time.
Rainfall-induced Landslide temporal probability prediction and meteorological early warning modeling based on LSTM_TCN model
Authors: Zhao yu , Chen lixia
Published: February 2023

Abstract: The occurrence time of investigated landslide hazard is not complete, leading to an error in the statistical relationship between rainfall and landslide. And the low accuracy of the critical rainfall threshold model will be built. And further, it will lead to an increase in the false positive rate of meteorological early warning. This study takes rainfall-induced landslides in the Wanzhou District of Chongqing from 1995 to 2015 as the research object. And Henghe Township, where historical disaster data is missing seriously, is the verification area. This study proposes a prediction model of the daily temporal probability of landslides occurrence on a certain day based on Long Short-Term Memory (LSTM) and Temporal Convolutional Network (TCN). The method is used to reconstruct the temporal information of rainfall-induced landslide events by simulating the nonlinear relationship between the occurrence time of landslides and rainfall. The landslide events after the reconstruction of temporal information were verified and selected, and then applied to the reasonable division of the E-D effective rainfall threshold curve, so as to establish the landslide meteorological warning model. The average temporal probability of rainfall-induced landslide occurrence on a certain day predicted by the proposed method reached 90.33%, which is higher than that of ANN (71.17%), LSTM (72.75%), and TCN (86.91%). Based on the temporal probability of landslide occurrence on a certain day which is higher than the 90% probability threshold, 18-time information including 42 landslides in Henghe Township of the verification area is expanded to 201. Compared with only using the historical landslide events, the meteorological warning model based on the expanded time information has a more reasonable warning classification, and the effective warning rate in the severe warning level is increased by 42.86%. The model method in this study is of constructive significance to the daily temporal probability prediction of rainfall-induced landslides on the regional scale and is helpful for the government to accurately model the risk decision of landslide meteorological warning.
Multi-source climate data to investigate the nexus between climate anomalies and landslides in high-mountain regions in the Alps
Authors: Paranunzio Roberta , Marra Francesco
Published: February 2023

As the effects of climate change become more and more evident in high-mountain regions, investigating the relation between climatic anomalies and geomorphic hazards becomes increasingly critical to predict the risk associated with such hazards and to develop reliable models. To do so, researchers often adopt statistical-based methods to detect climate anomalies at multiple time scales associated with the occurrence of different types of landslides. However, the in-situ observations commonly adopted for such studies may misrepresent some of these climatic variables in high mountain areas, sometimes leading to questionable results. For example, no daily precipitation anomaly is often reported for events such as debris flows, which are mainly triggered by short-duration precipitation. Additionally, collecting and quality-controlling in-situ observations is an extremely time-consuming task that prevents wide-scale applications of these methods. In this work, we exploit a consolidated statistical-based method to compare the results obtained from carefully controlled in-situ observations with the ones obtained from freely available quasi-global gridded datasets of (a) daily temperature observations from ENSEMBLES OBServation (E-OBS) and (b) half-hourly precipitation estimates from the Integrated Multi-Satellite Retrievals from GPM (IMERG). We focus on an extended database of 483 geomorphic hazards, including landslides, rockfalls and debris flows, occurred across the Italian Alps in the period 2000-2020. Our results show that the integrated use of open and free products is beneficial in different ways. Statistical tests indicate that E-OBS gridded temperature anomalies as well as multi-day IMERG precipitation anomalies provide as much information as in-situ observations, and can thus be used as easily available surrogates. More importantly, thanks to the ability of satellites to measure precipitation at the triggering locations, IMERG proved able to detect daily precipitation anomalies for many debris flows events for which in-situ data reported no precipitation. Examining the sub-daily variability of the triggering precipitation, we show that the anomalies missed by in-situ observations tend to be associated with events with high temporal, and hence spatial, variability such as the convective storms that usually trigger debris flows in the Alps. The use of quasi-global open datasets in place of in-situ observations can greatly speed-up the data retrieval and even provides an added value over in-situ observations. These results represent an important step ahead in the analysis of climate anomalies related to geomorphic hazards in high mountainous regions as they open the way to more accurate wide-scale applications.  
Methanogens-driven arsenic methylation as a precursory process for formation of methylated thioarsenates in sulfide-rich hot springs
Authors: Wang Luxia , Guo Qinghai , Wu Geng , Yu Zhicheng , Léon Ninin José Miguel , Planer-Friedrich Britta
Published: February 2023

Hot springs represent a major source of arsenic release into the environment. Speciation is typically reported to be dominated by arsenite, arsenate, and inorganic thiolated arsenates. Much less is known about the relevance and formation of methylated thioarsenates, a group with species of high mobility and toxicity. In hot spring samples taken from the Tengchong volcanic region in China, methylated thioarsenates contributed up to 13% to total arsenic. Enrichment cultures were obtained from the corresponding sediment samples and incubated to assess their capability to convert arsenite into methylated thioarsenates over time and in the presence of different microbial inhibitors. In contrast to observations in other environmental systems (e.g., paddy soils), sulfate-reducing bacteria did not contribute to arsenic methylation. Methanosarcina, the sole genus of methanogens detected in the enrichment cultures, as well as Methanosarcina thermophila (DSM 1825), a pure strain within the genus, did methylate arsenic. We propose that methylated thioarsenates in a typical sulfide-rich hot spring environment like Tengchong form via a combination of biotic arsenic methylation driven by thermophilic methanogens and arsenic thiolation with either geogenic sulfide or sulfide produced by sulfate-reducing bacteria.
Potential variations in groundwater quality for household and irrigation applications as affected by climate change
Authors: Alghamdi Abdulaziz G. , Aly Anwar A. , Ibrahim Hesham M.
Published: February 2023

Groundwater quality is being deteriorated as a result of climate change, overuse, and decreased precipitation, consequently impacting both agricultural productivity and human health. Thus, to investigate the potential variations in groundwater quality for irrigation and household applications, groundwater samples were collected from 88 different sites in Sarat Al-Baha region, Saudi Arabia. The Al-Baha region is characterized by a fragile agro-ecosystem, which is extremely susceptible to climate change. The collected samples were subjected to hydrochemical analyses to determine whether groundwater was suitable for irrigation and household consumption. Results showed that concentrations of nitrate and heavy metals were within maximum permissible limits for drinking purposes in 91% of the collected samples. However, because of elevated levels of arsenic and nitrate, 8% of the collected groundwater samples were deemed to be of poor or very poor quality for drinking purposes. The estimated saturation index revealed that the majority of the minerals in the samples were under-saturated, suggesting a higher possiblity of salinity owing to the dissolution of under-saturated minerals, conseqently increasing iron, calcium, magnesium, sodium, chloride, and sulfate concentrations. No sodicity risks were anticipated, despite of medium to higher salinity hazard. More than 90% of the collected groundwater samples had unsatisfactory quality for irrigation purposes due to the presence of salts in higher amounts, which could be due to lower precipitation and higher temperature in the study area. Hence, employing suitable management strategies to maximize groundwater utilization is recommended to avoid further groundwater quality deterioration. Groundwater discharge must be ristricted, cropping patterns should be altered to boost water productivity, and grounwater quality must be monitored on regular basis.
Natural constraints and the damaged Meli gold mining: forecasting impact on the water resources quality of the Meli area and the surroundings, Tigray
Authors: Abera Kaleab Adhena , Abrha Berhane , Gebreyohannes Tesfamichael , Hussien Abdelwassie , Hagos Miruts , Berhane Gebremedhin , Walraevens Kristine
Published: February 2023

Natural constraints and the damaged Meli gold mining: forecasting impact on the water resources quality of the Meli area and the surroundings, Tigray   Kaleab Adhena Abera 1, Berhane Abrha 2,  Tesfamichael Gebreyohannes 2, Abdelwassie Hussien 2 ,  Miruts Hagos 2, Gebremedhin Berhane 2, and Kristine Walraevens 11 Laboratory for Applied Geology and Hydrogeology, Department of Geology, Ghent University, Belgium (kaleabadhena.abera@ugent.be)2 Department of Geology, School of Earth Science, Mekelle University, Ethiopia Abstract: Meli is the only modern gold mining site in the Tigray region, Northern Ethiopia. Water resources of this area and the surroundings are currently very susceptible to pollution by toxic chemicals than ever before, due to both the natural geological setup of the area and anthropogenic impacts, specifically because of the recent war in northern Ethiopia. The war that was started on November 03, 2020, resulted in the complete destruction of the mining company and tailings dam due to bombing. This potentially could lead to the uncontrolled movement of wastewater from the dam to the environment. The area is characterized by quite complex geology and associated geological structures. In addition to the direct flow of contaminant plumes to downstream areas as surface water, the naturally existing geological fractures, as well as faults, could also act as conduits and increase the infiltration rate of the pollutants to the groundwater resource. In this research, integrated geological, structural, and remote sensing methods were applied. Mapping of geology and geological structures was compiled using both Spot and Landsat satellite images and a physical field survey conducted before the war started. Metavolcanics, metasediments, granite, and sandstone are the identified lithologies in the area. The detailed fracture measurement helps determine the possible flow direction of water and the pollutants. Totally, 110 structural measurements were taken, and the area is affected by a series of Neoproterozoic structures. These include WNW–ESE striking compression, NE –SW striking exfoliation fractures, and variably oriented faults. Moreover, structures such as folds, minor strike-slip faults, and joints were observed. The chemicals used in the gold mining company were evaluated. The Meli area tailing dam contains wastewater with a very high concentration of cyanide, caustic soda, heavy metals, and salts which are very toxic. The possible impact of these pollutants on water resources was forecasted and threat-solving mechanisms were proposed. The result of this research work will serve as a baseline for further pollution impact studies at a larger catchment scale and as an input for groundwater resource pollution modeling works of the Meli area and the surroundings.
Characteristics of rill morphology evolution in spoil tips under rainfall and inflow
Authors: Gao Zhaoliang , Lou Yongcai , Sun Guanfang , Li Yonghong
Published: February 2023

Soil erosion caused by rill development prevents vegetation recovery of the spoil tips and further accelerates soil erosion, which seriously threatens regional ecological stability. The rill morphological characteristics and rill erosion mechanism of spoil tips slopes were investigated with structure from motion (SfM) photogrammetry. Field runoff plots (5 × 1 m) with slopes of 32° and 36° were treated with rainfall-inflow at inflow rates of 8, 10, and 12 L min-1 and rainfall intensities of 90, 120, and 150 mm h-1. Results showed that rill development has three stages: formation, development and adjustment. Rill network on spoil tips slopes were generally dendritic rather than parallel forms. The average rill depth was the best geometric morphological indicator to characterize rill erosion, and geomorphologic comentropy was the best derived morphological indicator. Both of them have a highly significant logarithmic relationship with soil loss. Runoff shear stress was considered as the best hydrodynamic parameters to characterize the rill erosion mechanism, with a critical runoff shear stress of 1.53 N m-2. These results could contribute to further understanding of rill erosion and provide a useful reference for the prediction and control of soil loss from the spoil tips.
A new velocity field for El Salvador derived from combined InSAR and GNSS data
Authors: Portela Juan , Hamling Ian J. , Staller Alejandra , Béjar-Pizarro Marta , Hernández Douglas , Polío López Cecilia , Díaz Manuel
Published: February 2023

The country of El Salvador lies on an active tectonic margin, where the Cocos plate is subducting under the Caribbean plate. A crustal fault system, the El Salvador Fault Zone (ESFZ), crosses the country from East to West through the Central American Volcanic Arc, accommodating more than 1 cm/yr of differential deformation between the Chortís block and the volcanic forearc sliver. Here we use GNSS and interferometric synthetic aperture radar (InSAR) data to measure interseismic ground deformation across ESFZ. We have processed and updated GNSS data in more than 110 continuous and episodic stations in the region. GNSS results have been useful for determining the broad pattern of the tectonic signal in the area. However, they are scarce and unable to characterise complex behaviour in the intra-fault basins.SAR data acquired by the ALOS PALSAR L-band satellite (2006-2011), for both the ascending and descending tracks covering El Salvador, were used to form interferograms with a Small Baseline (SBAS) approach. The time series and average velocity were computed. The average coherence obtained for the area is overall good, and the results are coherent with the regional tectonics. 
Temporal and spatial changes in soil organic carbon and soil inorganic carbon stocks in the semi-arid area of northeast China
Authors: Wang Shuai , Zhuang Qianlai , Zhou Mingyi , Jin Xinxin , Yu Na , Yuan Ting
Published: February 2023

Soil organic carbon (SOC) and soil inorganic carbon (SIC) has important effects on soil physical, chemical and biological properties. They play an important role in coordinating the relationship between soil water and air, increasing soil water holding capacity and improving plant productivity. In this study, a boosted regression trees (BRT) model was developed to map the spatial distribution carbon stocks in the semi-arid region of Northeast China in 1990 and 2015. During the two periods, 10-fold cross-validation technology was used to test the performance and uncertainty of BRT model. In order to construct the model, 9 environmental variables (derived from climate, topography and biology) and 173 (1990) and 223 (2015) topsoil (0–30 cm) samples were used. The comparison between estimated and observed data shows that the RMSE of SOC and SIC stocks were 0.53 kgm− 2 and 0.19 kgm− 2 in 1990, and 0.65 kgm− 2 and 0.20 kgm− 2 in 2015, respectively. Elevation, normalized difference vegetation index, mean annual precipitation and Landsat band 3 were identifies as critical environmental factors for simulating the spatial distribution of SOC, accounting for 76.6 % and 70.3 % of the total relative importance in 1990 and 2015, respectively. Mean annual precipitation, mean annual temperature and topographic wetness index were the critical environmental factors for simulating the spatial variation of SIC during the two periods. Land use change also played an important role in the spatial variability of SOC and SIC stocks. In the past 25 years, soil carbon stocks decreased from 6.2 kg m− 2 in 1990 to 5.9 kg m− 2 in 2015. The spatial distribution pattern of SOC was high in northeastern area and low in southwestern area during the two periods, while the spatial distribution pattern of SIC was opposite to that of SOC stocks. The mapped soil carbon stock distribution is fundamental to future study of soil carbon cycle and regional carbon balance in semi-arid regions.
Data-driven approaches to soil microbial modeling
Authors: Luo Yiqi
Published: February 2023

Microorganisms catalyze almost all transformation processes of organic carbon in soil and are largely responsible for changes in soil carbon cycle feedback to climate change. To account for the microbial role in regulation of carbon-climate feedback, several dozens of microbial models have been developed in the past decades, mostly based on an idea that microbial biomass or microbial extracellular enzymes control decomposition of soil organic carbon (SOC). However, these idea-based models may or may not be well supported by empirical evidence. This presentation will show how data have been used to develop and test microbial models with three case studies. The first case study is to infer microbial mechanisms from observed patterns of lignin decomposition. Our study indicates that time-dependent growth and mortality of the microbial community, instead Michaelis-Menten kinetics, control microbial decomposition of lignin. The second case is to incorporate observed mechanisms into a carbon cycle model. Our meta-analysis indicates that changes in SOC under experimental warming and nitrogen addition are closely related to changes in microbial oxidative enzyme activities but not in hydrolytic enzyme activities. We directly incorporated this observed mechanism into a terrestrial ecosystem model to predict SOC changes. The third case study is to confront microbial models with nearly 58,000 vertical profiles of SOC over the globe to identify mechanisms underlying global SOC storage. Overall, scientists have developed different microbial models to explore all kind of possibilities while data offer reality. The data-model integration helps identify the most probable mechanisms under a Bayesian inference framework.
Tectonostratigraphic framework and depositional history of the South Korea Plateau, East Sea
Authors: Kim Kyoungjin , Yoo Donggeun , Yi Boyeon , kang Nyeonkeon
Published: February 2023

This paper presents a tectonostratigraphic framework and depositional history of the South Korea Plateau (SKP) using multi-channel seismic reflection profile and borehore data. Total sedimentary succession of the SKP is divided into four second-order megasequences (MS1 to MS4): the syn-rift (MS1), post-rift phase 1 (MS2), post-rift phase 2 (MS3), and syn-compression (MS4) megasequences. For these four megasequences, detailed seismic stratigraphy interpretation, including geomorphology, sediment thickness, and seismic facies distribution, was performed. In addition, we analyzed geometry and distribution patterns of geological structures (i.e. faults, folds, and syntectonic growth strata) to reveal their formation mechanism, timing, and deformation patterns. Based on these stratigraphic and structural interpretation, we suggested a tectonic and depositional history model of the SKP occurred in four stages, mainly controlled by tectonic movement. In Stage-1 (syn-rift; MS1), the SKP was rifted through domino-style block faulting, resulting in formation of half-graben style rift basins. In the incipient rifting period, volcanic materials were supplied from extensional faults and eruption center of the volcanics. Afterward, the plateau was dominated by lacustrine sedimentation with fan-delta development. In Stage-2 (post-rift phase 1; MS2), turbidite and hemipelagic sedimentation prevailed throughout the plateau. In addition, submarine mass wasting was frequently generated, caused by slope failures along the steep slope of adjacent continental ridges. In Stage-3 (post-rift phase 2; MS3), hempelagic sedimentation was predominant under a tectonically stable environment. In this mud-dominant environment, polygonal fault system was developed within the MS3 due to diagenetic processes, including compaction and water explusion. In Stage-4 (syn-compression; MS4), the SKP was filled with turbidite and hemipelagic sediments with intermittent mass transport deposits. Moreover, a certain volume of sediments were provided through feeder systems such as stacked channels and channel-levee complexes connected by submarine canyon (i.e. Gangneung and Donghae canyons).
Temporal and spatial variability of Environmental Lapse Rate distribution over Greenland and the central Arctic from 1980 to 202
Authors: Zhang zelu , Bamber Jonathan , Igneczi Adam
Published: February 2023

In this study, we derived the environmental lapse rate (ELR) with the new European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data ERA5 that could cover the central Arctic area and an extended period from 1980 to this day. We focus on the Greenland region, where the melting of the Greenland ice sheet plays a vital role in global sea level rise. The temporal and spatial variability of ELR distribution over the Greenland Ice sheet is fully explored in our research and the ELR values distribution over the other central Arctic land area including the Canadian archipelago, high latitude area of North America, and Eurasian are also studied. Our results indicate that ELR values differ dramatically in different seasons and areas, and the commonly used constant ELR −6.5 K/km is not suitable for the Arctic region. The monthly averaged ELR in Greenland shows an annual seasonal cycle with the lowest value is −2.5 K/km in winter. Near-zero ELR occurs in the northeastern marginal part of Greenland for the entire year except summer months. We talked about factors that might cause the near-zero ELR values that occurred over the research area in different seasons and hence research the inversion phenomenon in detail. 
The freshwater forcing that is equivalent to ice loss from Greenland in the real world is too small to affect the AMOC in climate model experiments. The freshwater flux (FWF) is comprised of runoff(liquid) and discharge(solid). To get a real and complete FWF as a freshwater forcing to activate the hosing experiment, the first step is to downscale near-surface temperature to get a higher-resolution runoff. ELR displays how the temperature near the surface varies with altitude and has been used for downscaling the near-surface temperature which will be further used for obtaining runoff. 

Our results could not only provide a reference for future near-surface temperature research and studies about inversion phenomena in different regions, but also depict the temperature vertical changes over the Arctic land area with ELR distribution. This research could provide a useful perspective on the changes in the Arctic cryosphere in recent years and should be helpful for a better understanding of mechanisms and feedback that drive the Arctic and subarctic climate changes. 
Numerical analysis of breather interactions
Authors: Nakayama Keisuke , Lamb Kevin
Published: February 2023

While the existence of breathers in the ocean is not clearly revealed, Rouvinskaya et al. (2015) suggested the possibility that breathers occurred in the Baltic Sea. In three-layer symmetric stratifications with the same density difference across each interface, the modified KdV equation (the Gardner equation with the quadratic nonlinear coefficient equal to zero) predicts that breathers exist. Therefore, the soliton-like characteristics of fully nonlinear breathers must be better understood. Thus, this study used fully nonlinear numerical simulations to investigate breather interactions by analysing overtaking collisions of two breathers in a three-layer fluid. As a result, an overtaking collision of two breathers is almost elastic when the ratio of the breather amplitude to the upper and lower layer thickness is smaller. Furthermore, the collision is found to remove the mode-2 structure, resulting in a significant role in forming breathers.
Foliar water uptake as a source of hydrogen and oxygen in cellulose of vascular plants
Authors: Kagawa Akira
Published: February 2023

Where do oxygen and hydrogen atoms of organic matter from terrestrial plant, such as O and H in cellulose, come from? We already know that O in cellulose originates from water within plants, instead of CO2 taken in via leaf stomata, and stable isotope tracers gave an answer to this question (Deniro & Epstein 1979, Science). We know that all vascular plants acquire water from the soil via their roots. However, in recent years, we have learned that plants can also acquire significant amount of water directly through their leaves (Burgess and Dawson 2004, Plant, Cell & Environment; and others) and foliar-absorbed water can be a source of oxygen atoms of sugars in leaves (Lehmann et al. 2018, New Phytologist). Then, an interesting question comes up to our mind: where does the water that eventually become O and H in cellulose come from? Until recently, these water sources were thought to only be taken up by roots, as we have learned from our introductory biology textbook (Dawson 2022, Tree Physiology). However, validity of this common perception has recently been questioned, when, using hydrogen and oxygen isotope tracer in vapour or mist form, two researchers have demonstrated that foliar-absorbed water can be assimilated into organic matter (Studer et al. 2015, Biogeosciences; Lehmann et al. 2018). However, relative contributions of foliar-absorbed water and root-absorbed water assimilation into O and H in cellulose have remained an open question.I therefore devised a labelling method that utilizes two different water sources, one enriched in deuterium and one enriched in oxygen-18, to simultaneously label both foliar-absorbed and root-absorbed water and quantify their relative contributions to plant organic matter (Kagawa 2022, Tree Physiology, https://doi.org/10.1093/treephys/tpac055). Using this new method, I will present evidence that, in the case of well-watered Cryptomeria japonica, hydrogen and oxygen incorporated into new leaf cellulose in the rainy season derives mostly from foliar-absorbed water (69% from foliar-absorbed water and 31% from root-absorbed water), while that of new root cellulose derives mostly from root-absorbed water (20% from foliar-absorbed water and 80% from root-absorbed water), and new branch xylem is somewhere in between (55% from foliar-absorbed water and 45% from root-absorbed water, see figure below). The novel dual labelling method first implemented in this study enables separate and simultaneous labelling of foliar-absorbed and root-absorbed water, and offers a new tool to study the uptake, transport, and assimilation processes of these waters in terrestrial plants. Thanks to our recent methodological breakthroughs, this new tool will soon be publicly available, as it has become easy to enclose wet tissue samples from labelled trees into smooth wall tin capsules without significant leaks, and our laboratory can now routinely analyze H and O isotope ratios of 200 samples that are labelled with heavy water per week. 
A method of evaluating safe operating space: focus on geographic regions, income levels and developing pathway
Authors: Zhang Yajuan , Li Shuangcheng , Wei Feili , Liang Ze
Published: February 2023

Safe and Just Space (SJS) is a framework for determining the range where the use of natural resources within the Earth’s carrying capacity can maintain human well-being. However, there has been no systematic monitoring and evaluation of their sustainability across time and space. Here we developed and applied a model and a sustainable development human safe operation space (SDHSOS) index to assess the sustainability capacity and development path of 149 countries from 2000 to 2018.The results demonstrate that 1) The overall sustainable development capacity of all countries is at the middle or lower level and that it has increased over time. 2) The sustainability of natural and socio-economic dimensions and their degree of change show obvious geographic differences and income differences. 3) The national development path divided by income is characterized by a decline in natural environment dimensions and an increase in socio-economic dimensions, which mainly reflects a traditional development path model that promotes social welfare at the expense of the natural environment. This study suggests that nations can accurately identify development characteristics, expand their comparative advantages is the key to improving sustainable development capabilities.
Comparison using different models between theoretical and experimental HVSR curves.
Authors: Tanzini Anna , Paolucci Enrico , Albarello Dario
Published: February 2023

The ambient vibration Horizontal to Vertical Spectral Ratios (HVSR) is a widely used technique to identify the seismic resonance phenomena induced by the presence of seismic impedance contrasts at depth. Moreover, the HVSR curve can be used to constrain the shear wave velocity (Vs) profile in numerical inversion procedures: for this purpose, different HVSR forward modeling were developed in the last decades, which differ from each other both for the basic theoretical assumptions related to the ambient vibration wavefield simulation and for the phases of the involved seismic waves. Recently, some works showed that strong similarities between these HVSR models exist. In particular, these approach were considered: one based on vertically propagating body waves; one based on the ellipticity of the fundamental mode of Rayleigh waves; one based on the contribution of uniformly distributed random sources at the surface and the full wavefield and one based on a diffuse random wavefield assumption. As concerns the last two models, full wavefield and surface wave only were taken into account. In view of these conclusions, the aim of this work is to perform a comparison of the different theoretical HVSR modeling with experimental HVSR curves. To accomplish this purpose, HVSR measurements were carried out at test sites belonging to the down-hole database of the Tuscany Region administration (Central Italy; https://www.regione.toscana.it/-/banca-dati-vel). In particular, more than 50 sites with Vs profiles characterized by the presence of the seismic bedrock (Vs≥800m/s) and strong impedance contrasts were selected. Velocimetric acquisitions were carried out using the three-directional 24-bit digital tromograph Tromino™ (https://moho.world/) and the ambient vibrations were acquired for 20 min with a sampling frequency of 128 Hz. In particular, the spectra of the single components were computed by averaging 20-s-long non-overlapping windows; a detrend and a 5% cosine taper were applied to each window, and the spectra were smoothed by using a triangular moving window with a frequency-dependent half-width (10% of central frequency). The horizontal components were combined with the geometric average. Theoretical HVSR curves were simulated considering the models mentioned above and taking into account the Vs and Vp profiles of the selected down-holes; density values were deduced from Vp by empirical relationships and, for not purely elastic models, damping values for Vp and Vs are assumed equal to 0.01 for all the layers. Finally, these curves were compared with the respective experimental ones in order to evaluate the differences in terms of frequency and peak amplitude as well as of overall trend.