bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of different mulching methods on soil moisture, fruit tree growth and yield in apple root zone yield of apple
Authors: Liu Wenqiu , Han Yuguo , Yang Yuxin , Zeng Li
Published: March 2024

Mulching is an important measure to conserve moisture and increase yield in dryland orchards of the Loess Plateau, and it is critical to realize high and stable yield and sustainable development of fruit crops. Based on field positioning obervation, the comprehensive effects of different mulching methods on soil water storage, fruit tree growth and physiological status, yield were investigated. Treatments were straw mulching (SM), horticultural fabric mulching (BF), black plastic film mulching (BM), white plastic film mulching (WM) and no mulching (CK). The results showed that: (1) Compared with CK, different mulching measures can significantly increase the average soil water storage in the 0-120 cm soil layer during the whole reproductive period, which can provide a basis for the realization of inter-temporal water regulation; (2) Different mulching methods can significantly increase the growth of apple branches and LAI, and enhance the tree strength; (3) SM, BF, and BM can significantly increase the net photosynthetic rate, and BM inhibited the occurrence of midday depression; (4) Under the BF treatment, the yield, the anthocyanin content, the soluble sugar content, sugar-acid ratio and fruit hardness were higher than CK. Using the comprehensive scoring method to obtain BF as the optimal mulching method, so BF was an appropriate technique to improve the hydrological status, fruit yield and quality of apple orchard soil in the Loess Plateau.
Plume-induced continental crust growth rate in Early Earth：Insight from numerical modeling
Authors: Zhong Xinyi , Li Zhong-Hai , Wang Yang
Published: March 2024

The origin of Earth’s felsic continental crust is still a mystery. The continental crust requires two-steps partial melting of mantle rocks. There are two proposed hypotheses for the continental crust growth in the Early Earth. One is the subduction-related magmatism, e.g. island arc, that produces intermediate to felsic magma which constitutes the early buoyant continental crust. The other is that the magmatism induced by mantle plume creates the thick basaltic crust, and which partially melts into continental crust. However, both two models have their deficiencies. It is still a controversial topic that when plate tectonics begins, which is an obstacle for applying the subduction-induced model in the Early Earth. On the other hand, the plume-induced model seems to be inefficient to support the continental crust growth. The previous numerical studies haves generally focused on the mechanisms of the continental crust formation, while efficiency of the model remains unknown. Thus, we simulated the melt transport process and integrated petrological model in our numerical model to evaluate the efficiency and the plausibility of continental crust production by mantle plume in the Earth’s history. The comparison between our model results and the reconstruction model of continental crust growth provides a new insight for the problem. The results indicates that the mantle plume is an efficient and possible way to support rapid continental crust growth in the Archean. Other mechanisms, e.g. subduction, may take dominant role since the Proterozoic because of low efficiency of plume-induced continental crust production.
Reconciling carbon isotope discrimination between leaf biomass and tree-ring to estimate water-use efficiency of global forests
Authors: Gong Xiao Ying , Yu Yong Zhi , Ma Wei Ting , Wang Xuming , Schnyder Hans
Published: March 2024

The response of intrinsic water-use efficiency (iWUE) to climate change is of uncertain magnitude owing to difficulties in accounting for physiological acclimation of plants. In particular, estimations based on controlled experiments, flux towers, and isotope data had significant differences in the historical trends of iWUE. Carbon isotope discrimination (∆) in leaf biomass (∆BL) and tree rings (∆TR) are vital indicators of how plants adjust water-carbon relations. The theory of photosynthetic 12C/13C discrimination is well-established. However, isotope fractionation downstream of photosynthesis, known as post-photosynthetic fractionation (∆post), also affects the 13C signature of plant tissues. The influence of ∆post on iWUE estimation remain uncertain, limiting quantitative study of iWUE using carbon isotopes.In this study, we derived a comprehensive, ∆ based iWUE model (iWUEcom) which explicitly incorporates mesophyll conductance, photorespiratory fractionation and ∆post. We characterized the ∆post based on the observations of ∆BL and online carbon isotope discrimination (∆online). The iWUEcom model was further validated with independent datasets of ∆BL, ∆TR, and leaf-level gas exchange data paired by species, years, and locations across the globe.∆BL was consistently larger than ∆online. Furthermore, the paired data of ∆BL and ∆TR showed a near constant offset, indicating that ∆post was different between leaf biomass and tree rings. Applying the material-specific ∆post values, iWUE estimated from ∆BL aligned well with that estimated from ∆TR and gas exchange. ∆BL and ∆TR showed a consistent iWUE trend with an average CO2 sensitivity of 0.15 ppm ppm-1 during 1975-2015, pointing out the overestimation of the historical iWUE response by the conventional model.A process-based framework has been suggested to predict iWUE of global forest based on isotope records in leaf biomass and tree rings, providing an ultimate tool to infer changes in carbon and water cycles under historical and future climate. 
The Sea Level during MIS5a, MIS5c in the Southwestern Coast of South Korea
Authors: Ryu Huigyeong , Lee Jun-Ho , Jung Hoi Soo , Shin Jaeryul
Published: March 2024

The study of marine terraces, which include a paleo-shoreline record, provides information on global sea level fluctuations and crustal uplift rates during the Late Quaternary period. This data is helpful in preparing for sea level rise in the upcoming 'Global boiling'. Currently, widely recognized sea level fluctuation curves are derived from oxygen isotope stages in ice cores and deep-sea cores. The data shows a 30-50m sea level fall during Marine Isotope Stage (MIS) 5d-5a. However, some studies conducted in various parts of the world have reported smaller declines in sea level than is commonly known. For instance, studies on the marine terraces of the east coast of the Korean Peninsula suggest that sea level may have been as low as -5 to -10 m during MIS5a and MIS5c. In this study, we investigated the marine deposits in Haenam, located on the southwestern coast of the Korean Peninsula. We found deposits in the sedimentary layers that correspond to MIS5c, which were located beneath layers formed during MIS5e. The age of the sediments was determined using optically stimulated luminescence (OSL) dating. Based on the altitude, formation process, and absolute age of the sediments, it is inferred that sea level was similar to the present during MIS5c in Haenam. Recent research on the southwestern coast of the Korean Peninsula has accumulated data on marine deposits formed during MIS5a and MIS5c. This paper presents the results of studies on sea level during MIS5a and MIS5c on the west and south coasts of the Korean Peninsula. This study suggests one perspective for MIS5a and MIS5c sea level across East Asia and to raise new questions. Specifically, the paper questions why sea levels are similar to present during what is known to be a glacial period. This study offers a fresh perspective on sea level fluctuations in East Asia and can improve our comprehension of the intricate correlation between sea level and climate change.
Phenological responses to urban heat and light in the Greater Seoul area 
Authors: Kim JiHyun , Sohn Soyoung , Kim Yeonjoo
Published: March 2024

Vegetation phenology is a critical indicator of terrestrial carbon and water dynamics; therefore, it is essential to understand its sensitivity to the changing climates, especially to rising temperatures. A wide range of phenological responses can be explored in urban areas where anthropogenic activities elevated temperatures as well as artificial lights. In this study, we analyzed one decade (2012 - 2021) of data on surface temperature, phenology, and land cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) and artificial lights at night (ALAN) data from the Visible Infrared Imaging Radiometer Suite (VIIRS) over the capital of South Korea and its surroundings. We calculated urban cover fractions (UCF) and estimated the long-term trends of the start of the season and the end of the season (ΔSOS and ΔEOS) and the temperature during the SOS and EOS (ΔTSOS and ΔTEOS) and in the ALAN (ΔALAN). We then investigated how much of those factors (i.e., ΔT, ΔALAN, and UCF) contributed to the ΔSOS and ΔEOS and explored temperature sensitivities of the ΔSOS and ΔEOS under different conditions. We found that the SOS appeared to advance by three days per decade (p = 0.068), while the EOS was delayed significantly (p < 0.001) by four days per decade over most of the study region. We also noticed that 70% of ΔSOS was primarily attributed to UCF, while ΔTSOS drove the rest. For the ΔEOS, the influence of ΔALAN appeared to be substantial (26%), with ΔTEOS having a similar contribution level (31%). We show that the temperature sensitivity of ΔSOS is higher by 4.5% in the highly urbanized areas, and the temperature sensitivity of ΔEOS is 4.3% higher in the regions with increasing lights. Our results suggest that vegetation phenological response to the increasing temperature would become complicated with the increases of urban-like conditions (i.e., higher levels of CO2 concentration), therefore highlighting the importance of further studies for a better understanding of terrestrial vegetation responding to the changing climates.This study is supported by the National Research Foundation of Korea (NRF) grants funded by the Korean government (MSIT) (2020R1C1C1014886 and 2022R1C1C2009543), the Korea Agency for Infrastructure Technology Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure, and Transport (22CTAP-C163540-02), and the Korea Environment Industry & Technology Institute (KEITI) funded by Korea Ministry of Environment (2022003640002).
Hurricane Harvey evolution process monitoring based on PWV
Authors: Zhan Wei , Liu Xiao
Published: March 2024

In 2017, Hurricane Harvey made two consecutive landfalls along the Gulf Coast of the United States on August 25th and August 30th, resulting in extreme precipitation and widespread flooding. The impacts were devastating, causing the loss of over 80 lives and significant economic damage. To understand the evolution of Hurricane Harvey, we utilized data from densely distributed permanent GPS stations for precipitable water vapour (PWV) and rainfall tracking from the Tropical Rainfall Measuring Mission (TRMM) 3B42 product, examining spatial and temporal characteristics. Applying the empirical orthogonal function (EOF) method, we analyzed typical spatial patterns of PWV before and after Harvey's passage, revealing an overall increasing trend in atmospheric moisture at various sites across the study area. This trend was particularly pronounced in regions affected by the first and second landfalls. By comparing the time series of PWV with the distance between GPS stations and the hurricane's eye, we calculated their correlation, finding a negative relationship, especially when the hurricane is gradually approaching the GPS stations, the correlation coefficient can reach -0.6 or a higher value. Notably, when the distance between GPS stations and the hurricane's eye was approximately 1000 km, PWV rapidly increased. As the water vapour values rose to around 55mm and maintained an upward trend, sustained precipitation occurred. During the passage of the hurricane, PWV remained at elevated levels, resulting in maximum rainfall. Once the hurricane moved away, PWV values rapidly decreased.
Electricity generation using biogas from food waste in Jakarta, Indonesia: Techno-economic and environmental impact analysis
Authors: Park Jin-Kyu , Jung Min-Jung , Yun Hui-Young , Wang Kyung-Hui
Published: March 2024

Food waste (FW) has a substantial environmental impact, contributing to 4.4 GtCO2 eq annually, equivalent to approximately 8% of total anthropogenic greenhouse gas emissions based on carbon footprints. Indonesia ranks as the world's second-largest food waste producer, estimated to generate 300 kg of food waste per capita per year. However, there is a scarcity of studies assessing the electricity generation potential and economic feasibility of biogas-to-electricity projects in Indonesia. This paper presents the recovery of biogas from food waste for electricity generation, aiming to determine its economic and environmental benefits for Jakarta, Indonesia. The food waste generation potential in Jakarta was estimated from 2024 to 2043, and the theoretical methane yield was calculated using Buswell's equation. The economic feasibility of anaerobic digestion projects was analyzed using various methods, including total life cycle cost, net present value, investment payback period, levelized cost of energy, and internal rate of return. Environmental impact assessment included air pollution (SO2, NOx, and PM10) and greenhouse gas (CO2 and CH4) emissions reduction. Methane yield from anaerobic digestion was determined to range from 315.9 to 616.5 × 106 m3/yr, with electricity generation potential between 721.5 and 1,407.9 Gigawatt-hours. Economic indicators demonstrated the viability of anaerobic digestion, with positive net present values. The net present value and levelized cost of energy for anaerobic digestion were $162.8 million and $0.095 per kilowatt-hour, respectively. Utilizing biogas from anaerobic digestion for electricity generation could displace 8.2 million tons of coal over the system's lifespan. This displacement would lead to reductions of 17.8 million tons of SO2, 13.9 million tons of NOx, 1.7 million tons of PM10, and 20.1 million tons of CO2 compared to coal combustion.AcknowledgmentsThis research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute (KEITI) funded by the Ministry of Environment (MOE).
Deep dynamics of subducting Indian slab revealed by mantle discontinuity structures beneath Hindu Kush from SdP observation
Authors: Cui Qinghui , Zhou Yuanze , Gao Yuan , Liu Lijun
Published: March 2024

Despite numerous geophysical observations on Hindu Kush, fine structures of mantle discontinuities remain less explored. By stacking near-source SdP phases from large datasets, we conducted systematic imaging of mantle discontinuities beneath Hindu Kush. Compared with the IASP91 model, we find an abrupt topographic transition of the 410-km discontinuity (410) from uplifts of up to 41 km within the subducting slab to depressions of less than 20 km near the slab edge, as well as a slightly depressed 660-km discontinuity (660) with depths of 660-668 km, and a fluctuant 300-km discontinuity (300) with depths of 264-337 km. We suggest that the sinking Indian slab elevates the 410 due to its cold interior, and deepens it near the slab edge by the hot mantle upwelling of slab-entrained mantle escaping below the slab, but has almost no impacts on the 660. Moreover, the fluctuant 300 can be explained by the coesite to stishovite phase transition in the eclogite-rich mantle within the subduction zone. When considered alongside other studies, our seismic results offer new insights into subduction dynamics of the Indian slab.
Assessment of soil moisture estimation using cosmic-ray neutron probe: Towards building Korean cOsmic-ray Soil Moisture Observing System (KOSMOS)
Authors: Jeong Jaehwan , Choi Minha , Kim Kiyoung , Kimm Hyungsuk
Published: March 2024

Soil moisture is a key factor controlling the hydrological phenomena at the land surface, i.e., the state and movement of water on the ground. Microwave remote sensing from space greatly contributes to reducing the lack of information on surface soil moisture. However, there are still challenges in the practical use of satellite-based soil moisture products for difficult situations such as dense vegetation, surface roughness, coarse spatial resolution, complex topography, etc. This is particularly true in South Korea, where more than 70% of the country is mountainous. Here, ground reference data from an observation network is essential for rigorous validation and retrieval of soil moisture. The Cosmic-Ray Neutron Probe (CRNP) is a promising approach for building a ground soil moisture observation network in areas with dense forests and mountainous terrain. CRNP requires no invasive sensor installation (i.e., no damage to vegetation and no interruption to soils) and also has intermediate spatial coverage that minimizes the scale mismatch between traditional ground data and satellite remote sensing products. This study assesses the applicability of CRNP for monitoring soil moisture in Korea. Hongcheon CRNP site, one of the prototype sites for the Korean cOsmic-ray Soil Moisture Observing System (KOSMOS), was established in August 2022, and this study used the Hongcheon site’s soil moisture datasets (one from CRNP and the others from multiple frequency-domain sensors) to calibrate CRNP-derived soil moisture and to evaluate satellite-based surface soil moisture product. Through this study, we discuss the potential of CRNP for enhancing the ground soil moisture observation network and the possibility of expanding the CRNP network throughout South Korea. Acknowledgment: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1A6A3A01087645), the National Research Foundation of Korea (NRF) grant funded by Ministry of Science and ICT (202300209986), and BK21 FOUR Program of Agriculture-forestry Bioresource Convergence Center (ABC), Seoul National University, Seoul, Korea.
Inventory and topographic analysis of glacial and high-altitude lakes in Kargil district, Union Territory of Ladakh
Authors: Prajapati Mohit , Garg Purushottam Kumar , Mukherjee Sandipan , Gupta Ajay Kumar
Published: March 2024

A glacial lake, characterized by its significant water volume, exists in association with a glacier (under, besides, and in front). They form due to glacial activities influenced by climatic variations. Glacial lakes generally impounded behind weak materials and can rupture suddenly due to various triggers, resulting to catastrophic floods known as Glacial Lake Outburst Floods (GLOFs). Lake’s topography particularity plays a crucial role in its formation and sustenance. Glacial lake related hazards are increasingly gaining attention due to their potential for causing significant damage and loss of life and property in high mountain regions worldwide. Therefore, it is imperative to regularly map and analyze various lake characteristics to understand any potential hazards originating from them.  Considering this, current study aims to present a comprehensive and updated inventory of glacial and high-altitude lakes in the Kargil district of Ladakh and systematically analyzes their types and topographic attributes. With the analysis of recent Sentinel-2 MSI imagery (2022), we identified a total of 355 glacier and high-altitude lakes in the Kargil district, encompassing an area of 4.8 ± 1.2 km2. These lakes are divided into four classes mainly based on their relationship with the glaciers: proglacial lakes away from the glacier (PGLA), proglacial lake in contact with glacier (PGLC), supraglacial lakes (SGL) and other lakes (OL). Results reveal that though PGLCs are comparatively low in number (85) but they occupy the largest area share of 60% in total glacial lakes covering an area of 2.88 ± 0.7 km2. PGLAs are 138 in number and occupy the second largest area of 0.9 ± 0.2 km2. There are large number (103) of SGLs with an area coverage of 0.32 ± 0.07 km2. OLs are limited in number (29) and cover 0.6 ± 0.1 km2 of area.  The lake sizes range from 0.001 km2 to 0.579 km2 with an average lake area of 0.013 km2 indicating that the lakes in the region are small in size and are in their initial phase of development. The mean elevation for the lakes is 4605 m and notably, ~21% of them predominantly oriented in a southward direction. The majority of lakes are situated on slopes with a gradient ranging 2-8° which reflects their potential to grow in size. It can be deduced from the analysis that the glaciated areas in Kargil region is dominated by large number of PGLC and PGLAs which are likely expand in future posing serious threat to the communities living in immediate proximities to the glaciers. Overall, this research contributes to our understanding of glacier lakes in the Kargil district of the Ladakh region, providing essential data for informed decision-making in order to minimize the glacial lake related hazards.Keywords: Glacial lake inventory; High altitude lakes; Ladakh Himalaya; Remote sensing; Glacier Lake hazards.
Responses of leaf functional traits to soil environment at different sand fixation stages in the Mu Us desertland
Authors: Tian Yun , Dai Yuanmeng , Xu Mingze , Zhou Yuhan , Ju Xiaoqian , Zha Tianshan , Jia Xin , Liu Peng
Published: March 2024

Leaf functional traits (LFTs) can directly or indirectly reflect the adaptation strategy of plants to the environment, influencing their survival, growth, and reproduction. However, there is still uncertainty as to the relationship between LFTs and environmental gradients, especially in resource-limited regions. In this study, we selected Artemisia ordosica communities as the research objects at four different dune fixation stages, including semi-fixed (D1), fixed (D2), soil-crust fixed (D3) and herbaceous-plant-covered fixed sand dunes (D4) in Mu Us Desert. Based on field investigation and laboratory analysis, we examined the characteristics of 13 LFTs and the relationship between of LFTs trade-offs and soil physicochemical environment under different dune fixation stages. It was found that (1) in community level, leaf area (LA) and specific leaf area (SLA) were the largest at D1, while leaf tissue density (LTD) and leaf dry matter content (LDMC) shown gradually increasing trend with dune fixation. The results indicated that plants will adapt to progressively increasing competition by reducing their photosynthetic capacity and enhancing their physical defense structures. (2) with ongoing dune fixation, the soil organic carbon content (SOC) and soil total nitrogen content (STN) were significantly higher in D2-D4 than that in D1, and soil water content (SWC) was the highest in D2, then decreased significantly in D3-D4 with increasing community species. (3) according to the results of redundancy analysis (RDA), the two main axes represented the soil physical condition (54.11%) and chemical condition (30.06%), respectively. And the SWC and SOC were the main factors affecting changes in LFTs during the dune fixation. Our results provide theoretical basis for understanding the resource use strategy and adaptation mechanism of desert plants under stress environments.
Flexible and physically based stage–discharge rating curves using a "double-Manning" approach
Authors: Wickert Andrew , Jones Jabari , Ng G.-H. Crystal
Published: March 2024

Rating curves translate between river stage (i.e., water level) and water discharge. They are applied ubiquitously for stream monitoring, water-resource estimation, and flood forecasting. However, they are calculated using a basic empirical power-law fit that lacks flexibility to robustly represent channel–floodplain structure or to adapt to changing hydraulic geometry or roughness. Furthermore, such empirical fits require many measurements of stage and discharge. Gathering these measurements is expensive and might not be possible if the channel and/or floodplain evolve before a sufficient range of flows may be measured.To address this deficit with a similarly simple but physically grounded approach, we present a strategy based on Manning's equation. This "double-Manning" approach implements Manning's equation within and above the channel and a power-law relationship – analogous to a generalized Manning's equation – for flows crossing the floodplain. We demonstrate that the double-Manning equation can effectively fit field data and, in the process, accurately estimate bankfull width, bankfull depth, channel Manning's n, and Manning-style power-law parameters for floodplain-flow characteristics. For sites lacking exhaustive field data, the physical basis of the double-Manning approach enables rating-curve creation using a combination of stage–discharge data and common field measurements of the channel and floodplain. Such rating curves may be adjusted as the channel and floodplain evolve to predict how geomorphic change might affect flow depth and flood inundation.The double-Manning approach may be run as a forward (predictive) or inverse (fit to data) model. Documented, open-source code may be acquired from GitHub (https://github.com/MNiMORPH/doublemanning) and Zenodo.
On the Predictive Analysis of Landslide Susceptibility by ML Approached– for the Case in Taiwan
Authors: Shou Keh-Jian
Published: March 2024

Due to the impact of climate change, the increasing frequency of extreme rainfall events, with concentrated rainfalls, commonly cause landslide hazard in the mountain areas of Taiwan. However, there are uncertainties for the predicted rainfall as well as the landslide susceptibility analysis.This study employs machine learning approached, including the logistic regression method LR and deep learning method CNN, to analyze the landslide susceptibilities. Together with the predicted temporal rainfall, the predictive analysis of landslide susceptibility was performed in the adopted study area in Central Taiwan. The uncertainties within the rainfall prediction was firstly investigated before applied to the landslide susceptibility analysis. To assess the susceptibility of the landslides, logistic regression method LR and deep learning method CNN were applied. The results of predictive analysis, with the discussions on the accuracy and uncertainties, can be applied for a better landslide hazard management in the study area.
Copernicus Data Space Ecosystem - Platform That Enables Federated Earth Observation Services and Applications
Authors: Milcinski Grega , Musial Jan , Leszczenski Jacek , Clarijs Dennis , de la Mar Jurry
Published: March 2024

The Copernicus Data Space Ecosystem (CDSE), a pivotal initiative of the European Space Agency (ESA) and funded by the European Commission, represents a groundbreaking advancement in Earth Observation (EO). It is an integral part of the ambitious Copernicus Programme, which has revolutionized EO data access and utilization across various sectors. The CDSE is more than a mere data repository; it is a collaborative platform where knowledge, expertise, and resources are shared and enhanced. This ecosystem approach is transforming the EO landscape, encouraging a more inclusive and participatory model where researchers, policymakers, businesses, and citizen scientists contribute to and benefit from the wealth of EO data. The CDSE stands as a beacon of international cooperation and a driver for sustainable development, setting new standards for leveraging EO data in addressing some of the most pressing global challenges.Central to the CDSE is its commitment to federation and cooperation, offering a flexible framework for integration and participation to data providers, remote sensing experts, and application developers. This approach fosters innovation and collaboration, ensuring that the ecosystem benefits from a diverse range of contributions. Data providers can upload their data to the ecosystem’s object storage, making it available to CDSE users under free or commercial conditions. This not only enhances the CDSE’s data repository but also expands the providers' reach. Remote sensing experts contribute their algorithms and workflows to the openEO Algorithm Plaza, a collaborative space for sharing and enhancing EO technologies and applications. Application developers can utilize CDSE's infrastructure and data to create solutions for specific needs like agricultural monitoring, demonstrating the ecosystem’s potential for application development.The CDSE's principle of federation extends beyond individual contributors to collaborations with other platform providers, enhancing the range of services and capabilities available to users. These partnerships are crucial for the ecosystem's growth, ensuring access to the best tools and data. The governance of the Data Space Ecosystem incorporates several third-party commercial providers and is designed to grow with additional contributions. It is based on European values of data sovereignty and privacy, ensuring trust, collaboration, and sustainability. The ecosystem maintains a clear distinction between publicly funded services and third-party offerings, both free and commercial. This open and federated approach makes CDSE a comprehensive solution for EO needs and solidifies its position as a leader in the EO community.
Modelling the complex response of debris covered glaciers on variations in climate and debris input 
Authors: Hardmeier Florian , Ferguson James C. , Vieli Andreas
Published: March 2024

Debris-covered glaciers are found in most glaciated areas in the world and often represent an important water resource for downstream areas. The dynamics of coupled debris and glacier interactions are not fully understood, which is why there has been an increasing effort in recent years to use numerical modelling to gain a better understanding thereof.As process understanding is quite limited, implementations of the debris-glacier system vary widely. Here we model the glacier in the along-flow dimension and set the focus on debris transport and tracking debris within and on the ice. We examine feasible implementations of involved processes and their coupled effects on glacier dynamics in a transient climate and that allows to vary the location and rate of debris input into the system.We perform a sensitivity analysis on this model and conduct experiments of increasing complexity, varying both climate forcing and debris deposition and on both simple synthetic and realistic bedrock topographies. Our modelling corroborates the earlier finding from earlier simpler models (without internal debris tracking) of strongly delayed retreat that only sets in after stagnation of the tongue. Our results show beyond that after retreat following warming, debris covered glaciers show a long-term re-advance effect, even when the absolute debris entrainment rate stays the same. We explain this by the increase of the debris-ice ratio in the debris deposition zone. Interestingly, results also show that – when accompanied with a permanent, regular supply of debris input– single large deposition events can have a sustainable growth effect on the glacier, even after the debris from that event has exited the system. In experiments with below century scale fluctuations in climate and/or debris input the glacier length does not really respond. We conclude that this insensitivity and the response of debris covered glacier in general is not only influenced by debris insulation on the tongue, but is also affected by the long time-scale (centuries) involved in transporting the debris through the glacier system.
Effect of Rainfall on Evolution of the wind turbine wake：A LES Study
Authors: Yang Xuefeng , Chen Shengli
Published: March 2024

The rainfall directly affects wind turbine operation by eroding the turbine blades and changing their aerodynamic performance, however, little research has been conducted on the effects of rainfall on wake evolution. The present study simulates the impact of rainfall on wind turbine wake using a coupled LES-ADMR model, in which a double Euler method is employed for the rainfall injection. The numerical simulation results indicate that the rainfall reduces the wake wind speed in the sweep area while increasing it in the outer region of the upper blade tip, reaching up to 2.1% for increment. Rainfall also weakens the turbulence in the near wake and the outer region of the top tip (as much as 2.0%), with the influence extending up to 10 diameters downstream the wind turbine. These modifications are positively correlated with the rainfall intensity and inversely correlated with wind speed. By analyzing the rainfall-induced changes in MKE (Mean Kinetic Energy) and TKE (Turbulent Kinetic Energy) budget terms, the study reveals that the alteration of turbulent radial transport of MKE is the main cause of changes in wind speed, while the variation of shear production of  TKE is responsible for the turbulent intensity changes. The rainfall-induced change of  reynold stress u'w' is the root cause of the above phenomenons.
Unraveling the sources of uncertainty in China's top-down methane emission estimates
Authors: Zhong Huiru , Shen Lu , Qu Meng
Published: March 2024

Accurate quantification of methane emissions is critical for setting and tracking the mitigation goals. However, previously estimated anthropogenic methane emissions in China differ by up to 50% among different studies. Satellite observations are expected to reduce the uncertainty, but large discrepancies still exist in earlier quantifications. Here, using satellite observations from the blended TROPOMI+GOSAT product, we conducted an ensemble of high-resolution (~50 km) inversions to assess the sources of uncertainty in the quantification. Overall, satellite observations can provide robust constraints on China’s total emissions but are less effective in quantifying individual sources with lower emission magnitudes. Of all sectors, emissions from coal mines and livestock can be well constrained due to frequent satellite observations, higher emission magnitudes, and lower prior uncertainty. Furthermore, we constructed marginal cost curves for emission reductions from each source to better inform future mitigation measures.
Pretraining Foundation Models: Unleashing the Power of Forgotten Spectra for Advanced Geological Applications
Authors: Lee An-Sheng , Lin Hsuan-Tien , Liou Sofia Ya Hsuan
Published: March 2024

X-ray fluorescence (XRF) core scanning, renowned for its high-resolution, non-destructive, and user-friendly operation, is pivotal in geological research for analyzing chemical, physical, and biological signals. Despite the extensive applications of XRF data for various research purposes, the quantification of this data into specific geological proxies remains challenging due to the inherent non-linearity caused by simple sample pretreatment during core scanning. Leveraging advancements in deep learning, computing power and large-scale scientific drilling programs, our study aims to address this non-linearity by harnessing the often-overlooked raw XRF spectra stored in laboratory databases. We introduce an approach involving self-supervised pretraining on 54,643 spectra from marine sediments in the high-latitude sectors of the Pacific Ocean (cruises SO178, SO264, PS97, PS75, LV29). Our model, underpinned by a deep bidirectional image transformer (ViT-base), is trained to reconstruct heavily masked spectra (75%) with an R2 accuracy of 0.996, demonstrating its proficiency in feature extraction from limited data portions. This foundational model is anticipated to serve as a versatile tool for various downstream geological applications after finetuning with specific labeled data, such as quantifying high-resolution calcium carbonate (CaCO3) and detecting machinery anomalies. Future work includes expanding the spectrum database with diverse materials and machine settings to enhance the model's generalizability, ultimately broadening its applicability beyond core scanning for geological applications to encompass all XRF measurement techniques.
Barchan collision using multiple crest lines model
Authors: Navarro Yabe Sofia , Shiraishi Masashi , Nishimori Hiraku
Published: March 2024

Crescent-shaped dunes called Barchans are found in areas with constant wind direction and little sand. They often cluster together, so we need to consider the interaction between each of the barchans. In previous research, two models represent the movement of barchan: one is the ABCDE model, which describes the collision of barchan by similar triangles in the cross-section, and the other is the single crest line model, which describes the movement of a single barchan by a single line. However, the single crest line model has the problems that the conservation of sand is not strictly considered and that the shape and height of the dune do not reach a steady state. Therefore, in this research, we take into account the conservation of sand and improve the single crest line model. As a result, we confirm that even near the boundary of the barchan, where the sand height is very small, the sand balance is kept and the shape of the barchan reaches a steady state. Numerical simulations of this single crest line show it could reproduce various phenomena that had been confirmed with the cellular model, such as the situation when sand was supplied to the barchan. In addition, to handle the behavior of multiple barchans in 3D space, a model that extends the single crest line model to multiple lines is effective. Hikosaka (master thesis, Hiroshima University, 2019) tried to derive a ”multiple crest lines model” by adding the idea of the ABCDE model to the single crest line model (Fig. 1). However, it is still in the process of completion. By using the sand balance matching method proposed in this research, we can handle the influence of sand at both ends of the barchan more accurately. Then we can make the model of dune collision phenomena with multiple crest lines. In our model, we also include a method for calculating the time evolution of a valley between two dunes created during their collisions. We compare the result of numerical simulation with the results of water tank experiments in previous research to analyze whether the collision patterns of recombination, breakup and coalescence appear or not. By using our proposal way, we can calculate the multiple dunes collision (Fig. 2). This means we get a step toward theoretical analysis of the dynamics of multiple dunes.
Reestimated slab dehydration fronts in Kuril-Kamchatka using updated three-dimensional slab thermal structure
Authors: Zhu Weiling , Ji Yingfeng
Published: March 2024

Previous subduction thermal models are inconsistent with the values of forearc heat flow (50-140 mW/m2) and global P‒T conditions of exhumed rocks, both suggesting a shallow environment 200~300°C warmer than model predictions. Here, we revaluate these problems in Kuril-Kamchatka using 3-D thermomechanical modeling that satisfies the observed subduction history and slab geometry, while our refined 3-D slab thermal state is warmer than that predicted by previous 2-D models and better matches the observations involving exhumed rock records. We show that warmer slabs create hierarchical slab dehydration fronts at various forearc depths, causing fast and slow subduction earthquakes. The multilayered subduction regime and a large downdip thermal gradient of > 5°C/km beneath Kuril-Kamchatka indicate a stratified characteristic effect on slab dehydration efficiency. We conclude that fast-to-slow subduction earthquakes all play a key role in balancing plate coupling energy release on megathrusts trenchward of high P‒T volcanism.
Three-dimensional MHD simulation of lunar induced magnetic field generated by lunar metallic core
Authors: Yi Siqi , Xu Xiaojun , Xie Lianghai , Wang Xing , Xu Qi , Zhou Zilu , Man Hengyan , Luo Lei , He Peishan , Yang Pu
Published: March 2024

Comprehending the internal structure of the Moon is crucial for uncovering its formation and evolution. The existence of the lunar core can be proved by several pieces of evidence, including electromagnetic sounding analyses, mass and moment of inertia analyses, and seismic analyses. However, the precise size and composition of the lunar core are still unknown. In this study, the induced magnetic field generated by the lunar metallic core is illustrated through a three-dimensional MHD simulation. Several cases have been discussed in which the lunar core are set with different electrical conductivities and thicknesses. Compared to the hybrid model, our MHD model can calculate more accurate results with a more refined grid. Our simulation can capture the variations of parameters (plasma densities, temperature, and flow speed) in original and final conditions, while the hybrid model cannot.
Electrodynamic changes in the ionosphere due to large lithospheric disturbances
Authors: Sun Yang-Yi
Published: March 2024

A solar storm can trigger severe geomagnetic and ionospheric disturbances, and activities originating from the Earth’s surface can do so as well. This presentation will introduce the sudden changes in the ionospheric plasma structure and electrodynamics after large lithospheric disturbances, such as earthquakes/tsunamis and volcanic eruptions. The main focus will be on the two significant events of the magnitude 9.0 Tohoku earthquake/tsunami (38.3°N 142.4°E) in the northeastern sea area of Japan on 11 March 2011, and the undersea volcanic eruption in Tonga (20.6°S 175.4°W), Central Pacific, on 15 January 2022. This presentation will also discuss the main characteristics of disturbances in ionospheric structures and electrodynamics. Investigating the two events enhances our comprehension of the sensitivity of the ionosphere response to lithospheric activities.
Timing and climate dynamics of centennial-scale abrupt climate change during early Marine Isotope Stage 3 inferred from the INTIMATE network
Authors: Dong Xiyu
Published: March 2024

The study of centennial-scale events remains underdeveloped, with little knowledge of events timing, their inter-regional phasing, and the role played by the Atlantic Meridional Overturning Circulation (AMOC) during these events (1, 2). Here we present four high-precision speleothem δ18O records from Asian summer monsoon (ASM) and South American summer monsoon (SASM) domains, spanning a centennial-scale 55 ka event. These speleothem records are comparable to those previously published from Europe, indicates that the 55 ka event occurred simultaneously in the European and ASM domains. The synchronous timing during the centennial-sale events is consistent with what has previously been observed during millennial events (1). It is therefore likely that abrupt climate change teleconnections between North Atlantic and ASM hydroclimates would have pervasively persisted during the last glacial period. Additionally, the speleothem records were compared with the bipolar ice-core and marine sediment records of INTIMATE. The “monsoon seesaw” pattern between the ASM and SASM records over 55 ka event is consistent with a northward shift of the Intertropical Convergence Zone (ITCZ). Our study suggests that the 55 ka event was caused by AMOC reinvigoration. Ref.(1) Corrick, E C. et al. Synchronous timing of abrupt climate changes during the last glacial period. Science 369,963-969 (2020).(2) Lynch-Stieglitz, J. The Atlantic Meridional Overturning Circulation and Abrupt Climate Change. Annual Review of Marine Science 9, 83-104 (2017). 
Integrated Perspective of the Biological Pump in the North Pacific: Synergy from BGC-Float Observations and Ecosystem Model Simulation
Authors: Huang Yibin , Chai Fei
Published: March 2024

The North Pacific (>20°N) stands out as a significant carbon sink, contributing to approximately 25% of the global oceanic CO2 uptake and absorbing around 0.5 Pg C yr-1 from the atmosphere. Despite the well-established importance of the biological carbon pump in maintaining this regional carbon sink, our current understanding of the strength and efficiency of the biological pump in this vast region remains incomplete. Historical studies have primarily relied on extrapolations from a limited number of observations.In this study, we utilize data from 85 BGC-floats, covering over 160 annual cycles, to constrain essential fluxes relevant to the biological pump in the North Pacific, including net primary production, the export of distinct biogenic carbon, and air-sea CO2 flux. Furthermore, we combine the output from a well-constrained regional ecosystem model (ROMS-CoSiNE-Iron Model) to gain mechanistic insights into how the food-web dynamics drive the strength and efficiency of the biological carbon pump across different ecosystems.Overall, our study offers an integrated perspective on the North Pacific biological pump by leveraging high-resolution observations from the BGC-float array and simulation from an improved ecosystem model.
THERESA project: a study to enhance algorithms for processing data from the SBG-TIR mission in volcanological field
Authors: Silvestri Malvina , Buongiorno Maria Fabrizia , Romaniello Vito
Published: March 2024

The THERESA project, which stands for THErmal infRarEd SBG Algorithms, seeks to improve algorithms for processing data obtained from the SBG-TIR (Surface Biology and Geology – Thermal InfraRed) mission. By leveraging the mission's technical features, THERESA aims to improve and adapt specific algorithms to study geological processes and develop new ones that could get advantages by using SBG-TIR spectral channels in the VIS and MIR-TIR range. Over the two-year duration of the project, THERESA will play a vital role in advancing the study of terrestrial phenomena also considering the high revisit time of SBG, which will be of 3 days worldwide over land.SBG-TIR data will benefit diverse thematic areas, ranging from vegetation analysis to monitoring volcanic eruptions and fires. The project aims to derive several key parameters, including the estimation of ash and SO2 emissions from volcanoes, surface temperature, detection of hotspots, and the calculation of FRP (Fire Radiative Power) during High Temperature Events (HTEs). THERESA distinguishes itself through its innovative algorithmic advancements, providing comprehensive support to the SBG-TIR mission. Finally, suitable sites for CAL/VAL activities will be identified, and measurement campaigns will be conducted coinciding with the passages of currently operational TIR satellites for the validation of the algorithms under study.
A Comprehensive Method to Unveiling Uncertainty in Multi-Factor Systems
Authors: He Bishuo , Zhao Chunsheng
Published: March 2024

The accurate assessment of influencing factors in multi-factor systems is crucial, but current methodologies face challenges in evaluating uncertainty comprehensively. In aerosol radiative forcing, existing methods may lack completeness, potentially leading to erroneous conclusions. This study introduces a universally applicable method for precise sensitivity analysis of influencing factors in multi-factor systems. Two measurement dimensions for sensitivity analysis methods are established: accurately expressing sensitivity and quantifying sensitivity. Combined utilization of different methods allows for a comprehensive analysis. The proposed method can simultaneously express and quantify sensitivity, including the analysis of nonlinear components unaffected by the absence of factors. In a sensitivity analysis on aerosol optical parameters, the aerosol shell complex refractive index (CRI_shell) emerges as the most sensitive factor. Calculations reveal substantial variability (5% to 91%) in the proportion of nonlinear components resulting from factor interactions. This emphasizes the importance of employing methods resistant to nonlinear influences, as susceptible methods may introduce significant biases. The proposed sensitivity analysis facilitates factor importance assessment at three levels: primary and secondary factors, sensitivity ranking, and quantified sensitivity. This method exhibits universality and holds promising prospects for practical applications in the field. Results provide a valuable reference for future model parameter settings and routine observations.