bluuebunny/crossref_metadata_2025 huggingface dataset:
Dust Characterization and Evaluation of Indoor Environmental Quality (IEQ): Case Study of AFTU Buses in Senegal 
Authors: Tchanche Bertrand , Papathanasiou Sotirios , Namdeo Anil
Published: March 2024

Africa is experiencing a high urbanization rate, ~4% with megacities emerging like Cairo in Egypt, Lagos in Nigeria, Kinshasa in Democratic Republic of Congo. In parallel, a deterioration in air quality is being witnessed. Road traffic contributes significantly to atmospheric pollution through unregulated traffic, poor roads’ design, poor fuel quality and surge in vehicle imports. Arica is the continent with lowest roads densities and with most unpaved roads. Congestion is now frequent in cities with adverse consequences on the economy, health, and society. High daily temperature observed in tropical climates, and favourable wind speed favour dust resuspension and Sahara dust dispersion. Literature review shows a less focus on in-cabin dispersion and impacts. The present work regards a study of the indoor environmental quality (IEQ) of the public transport buses provided by the AFTU company in the city of Thiès, in Senegal. A Particle Plus 8301-AQM2 Series handled optical particle counter (OPC) was used as it offers a good characterisation of the fine particles. the outdoor air, the vehicle itself and the occupants were identified main pollutants sources. Fine particles concentrations, carbon dioxide (CO2), temperature and relative humidity were recorded on several routes at different periods of the day and for several days during the rainy season. Recorded data show high concentration of PM2.5 which increases over time (from 25 up to 300 µg/m3) depending on outdoor conditions and the areas crossed by the vehicle. Variations of PM concentration in different channels: 0.5, 1, 2.5, 5 and 10 were also analysed. Recorded values showed very small mass fraction of 0.5 and large proportion of 5-10 µm diameter particles. CO2 concentration (300-900 ppm) varies with the number of passengers during the trip. The temperature was above 30 °C and the relative humidity, in the range 40-70%. The speed analysis shows high frequency variations and was found low, ~2.5 m/s. A conclusion that emerged is that keeping doors and windows open help in eliminating excess CO2 but ends in high level of particulate matter concentration in the cabin.
Step-change in supraglacial pond area on Tshojo Glacier, Bhutan, and potential downstream inundation patterns due to pond drainage events.
Authors: Carr Rachel , Barrett Amy , Rinzin Sonam , Taylor Caroline
Published: March 2024

Climate change is causing Himalayan glaciers to shrink rapidly and natural hazards to increase, whilst downstream growth in population, infrastructure and agriculture is increasing vulnerability. Glacier shrinkage promotes the formation of glacial lakes, which act both as a resource and a hazard, via glacier lake outburst floods (GLOFs). GLOFs can rapidly generate large volumes of water and sediment, which threaten life, property, and infrastructure downstream, and Bhutan is one of the most vulnerable countries globally to these hazards. Almost all documented GLOF casualties in High Mountain Asia have been from ice-surface ponds or moraine dammed lakes, with supraglacial ponds often being responsible for recurrent GLOFs. Here we use remotely sensed imagery to quantify changes in supraglacial water storage on Tshojo Glacier, Bhutan, where previous supraglacial pond drainage events have necessitated downstream evacuation. Results showed that both total ponded area and its interannual variability doubled between 1987-2003 and 2007-2020, which was predominantly driven by large increases in the areas of the biggest ponds. These ponds drained regularly and have occupied the same location since at least 1967. Numerical modelling results show that pond outburst floods can reach between ~6 and 65 km downstream, impacting Lunana and Wolathang under the worst-case scenario.
HIDRA3: A Robust Deep-Learning Model for Multi-Point Sea-Surface Height Forecasting
Authors: Rus Marko , Mihanović Hrvoje , Ličer Matjaž , Kristan Matej
Published: March 2024

Accurate sea surface height (SSH) forecasting is crucial for predicting coastal flooding and protecting communities. Recently, state-of-the-art physics-based numerical models have been outperformed by machine learning models, which rely on atmospheric forecasts and the immediate past measurements obtained from the prediction location. The reliance on past measurements brings several drawbacks. While the atmospheric training data is abundantly available, some locations have only a short history of SSH measurement, which limits the training quality. Furthermore, predictions cannot be made in cases of sensor failure even at locations with abundant past training data. To address these issues, we introduce a new deep learning method HIDRA3, that jointly predicts SSH at multiple locations. This allows improved training even in the presence of data scarcity at some locations and enables making predictions at locations with failed sensors. HIDRA3 surpasses the state-of-the-art model HIDRA2 and the numerical model NEMO, on average obtaining a 5.0% lower Mean Absolute Error (MAE) and an 11.3% lower MAE on extreme sea surface heights.
Managing geoparks -Practical and application 
Authors: Lin Jiun-Chuan
Published: March 2024

Managing geoparks ---Practical and application Lin, Jiun-Chuan, Department of Geography, National Taiwan UniversitySu, Shew-Jiunn, Department of Geography, National Taiwan Normal UniversityWang, Wen-Cheng, Department of Geography, National Taiwan Normal UniversityLiu, Ying-San, Department Natural Resource and Environment, Tong-Hua University  AbstractThis paper mainly focuses on managing geoparks in Taiwan.There are 10 geoparks according to the Cultural Preservation Law in Taiwan and formed a Taiwan Geoparks Networks (TGN). Geo-heritage is a combination of geology and physical processes as well as the cultural characters. The awareness of the value of geo-heritage is getting more and more important in Taiwan after designation of geoparks.The methodology to conserve the geo-heritage is rather unclear before 1985 in Taiwan. However, through designation of geoparks, the conserving geo-heritage, in terms of landscape conservation, became clearer for local people to practice.This study demonstrates some typical ways of conserving landscapes in Taiwan geoparks. First of all, through environmental education; second, through legislation; third, through local participation on geopark affairs; fourth, through guided tour by local interpreters.According to Environmental Education Law, everyone including all departments of different level of government workers and schools have to take 4 hours’ environmental education course every year. It helps to enhance the awareness of environment conservation including conservation of geo-heritage. By Cultural Heritage Preservation Law, the designation of geoparks and natural monuments are the tools to conserve the landscapes. Local participation as local guard on geoparks are also the ways to prevent further damages. Through interpretation on the aesthetic/ scientific value by local licensed guides for visitors, it is a way to prevent further damage by human activities.This study demonstrates the such progresses at Taiwan Geoparks. Key words: geo-heritage, geo-conservation, environmental education, Taiwan geoparks
Numerical modeling of basement inheritance and salt decoupling effects on the structural evolution of the Zagros Fold-Thrust Belt
Authors: Gomar Fatemeh , Ruh Jonas B. , Najafi Mahdi , Sobouti Farhad
Published: March 2024

Fold-thrust belts are complex tectonic domains formed in response to near- or far-field compressional stress fields in the Earth’s crust. The complexity of structural style in theses belts is controlled by multiple factors. The presence of mechanically weak layers, defined by rocks that exhibit lower strength than their surroundings, play a significant role in the formation and evolution of fold-and-thrust belts. In this research, a two-dimensional numerical finite difference model incorporating a visco-elasto-plastic/brittle rheology is utilized to investigate the structural evolution of the Fars arc in the southeast of the Zagros fold-thrust belt. The modeling includes the tectonic inversion process, from Permian-Triassic rifting of the Neo-Tethys Ocean to the Oligocene-to-present continental collision between the Arabian and Eurasian plates. The Eulerian grid dimensions were considered as 500 km in length and 60 km in thickness, respectively, comprising 1101×121 nodes. Each cell contains 16 Lagrangian markers that carry the information and properties of each layer. According to the stratigraphic column of the Fars arc, there are 30 km of basement overlain by a 2-km-thick salt layer with a 3-kilometer-thick Palaeozoic sedimentary sequence above the salt layer. Furthermore, to replicate the interplay between Earth's internal and surface dynamics, a 25-kilometer-thick layer representing air is incorporated at the uppermost part of the model to approximate a free surface. The experiments include three inherited basement faults. The role of pre-existing weak zones in extensional tectonics is the shaping of rift basin geometry, especially the formation of half grabens. In the convergence phase, fold-thrust-belts with a basal detachment layer and pre-existing faults produce folding at two distinct scales. The faulting in the basement develops long wavelength folds in the sedimentary cover, while the presence of a salt layer shapes the smaller wavelength folds and thin-skinned thrust faults that extend from the detachment layer to the surface. The reactivated faults play an important role in stress transfer, leading to the emergence of new faults and seismic events. The results indicate that deformed listric faults show a meaningful correlation with the depth distribution of earthquakes throughout the Fars arc. The outcome associated with the presence of a thick basal salt layer and involvement of the basement exhibit a correlation with the structural style of the Fars arc.
Serious game as a tool for understanding the need for adapting our neighbourhoods to climate change
Authors: Kuchcik Magdalena , Cieszewska Agata , Adamczyk-Jabłońska Joanna , Dudek-Klimiuk Joanna , Giedych Renata , Klimaszewski Krzysztof , Łączyński Marcin , Maksymiuk Gabriela , Pusłowska-Tyszewska Dorota , Wałdykowski Piotr
Published: March 2024

The strategic, serious games could be one of the most interesting and effective educational tools in climate change action methods. This is why interdisciplinary project Co-Adapt - Communities for Climate Change Action (NOR/IdeaLab/Co-Adapt/0002/2020-00; https://coadapt.pl/en)​ aims to develop an integration toolkit based on both board and  computer game to support resiliency and citizen engagement in city-communities, empowering them in responding to new climate change challenges with bottom-up involvement.The game features simulations that allow local community to transform their neighborhoods into more resilient to the climate change. The game is adapted to local environmental and spatial conditions so people can play in a group on their real neighborhoods maps what stimulate higher motivation for participation in climate change transformation. The residents play together and they are forced to co-operate. They will explore various choices available for their neighborhoods (from wide, but limited and detailed range of solutions connected with green and blue infrastructure, renewable resources, climate-friendly changes of colors of facades and roofs etc.) and consequences (costs, savings, climatic benefits). The workshop toolkit integrates best practices collected from communities that are already involved in climate change actions in Norway, Denmark, France or USA and which were visited by project’ leaders.The pilot board games were played October-November 2023 in five neighbourhoods in Warsaw diversified in relation to exposure to urban heat island, flood risk etc., urban structure and socioeconomic factors. They were carefully chosen after consultations with Warsaw City Council out of the most active local communities and on city-owned land. City ownership is crucial because at the end of the game each of the community will be able to implement some solutions from the game up to the sum of c. 6800 € (30 000 PLN). The residents could eg plant the trees, sow a flower meadow, create bioswale trough or start a small orchard.Co-Adapt game is completely new idea of ​​implementing science into the behavior of local communities in order to arouse their will to act together, to improve their living environment, to adapt to climate change and to mitigate this change.   
Crustal structure of onshore-offshore Iberia, Morocco, and their rifted continental margins, from constrained 3-D gravity inversion using variable mesh depths
Authors: Welford J. Kim
Published: March 2024

A new onshore-offshore 3-D constrained gravity inversion methodology that incorporates onshore topography and laterally variable inversion mesh depths is used to determine the crustal density distributions, Moho depths, and crustal thicknesses of Iberia, Morocco, and their respective rifted continental margins. The results largely show an excellent correspondence with crustal characteristics determined from sparsely distributed controlled-source and passive seismic experiments, while also allowing the layered density structure of the region to be explored and analyzed in terms of upper, middle, and lower crustal layers. These detailed regional views as a function of depth can improve characterization of crustal types (continental versus oceanic versus transitional), and the resulting interpretations can be directly compared against equivalently derived crustal characteristics for onshore-offshore Atlantic Canada, which encapsulates both Iberia’s and Morocco’s conjugate rifted margins. Collectively, the conjugate 3-D crustal-scale density models allow for the extraction of mega-transects across both sides of the southern North Atlantic, joined together back through geological time using kinematic plate reconstructions.
Joint long-period P and S velocity inversion for Earth's mantle based on deep learning
Authors: Su Jun , Houser Christine , Hernlund John
Published: March 2024

Many large-scale structures in the mantle have been proposed to explain seismic observations and constrain geodynamic models. While the geophysical community cannot agree on the morphology and nature(s) of large low shear velocity provinces (LLSVPs) due to the difference in approaches, decorrelated P and S velocity anomaly (dVP no longer proportional to dVS), inherently associated with changes in composition and/or phase, can help examine geodynamic models and imply the thermal/chemical evolution of the mantle. To further apply the inference to finer structures and to improve the precision for quantitative mineral physical implications, it is necessary to build a new seismic dataset for P and S waves measured in a self-consistent manner.In this study, we trained a phase-picking model using code modified from EQTransformer (Mousavi et al., 2020). Our training dataset includes 65,298 traces, where teleseismic P and S arrivals are manually picked at the long-period (~20 sec) onset. Based on the machine-learning architecture proven useful for seismicity at local to regional distances, we managed to reproduce the manual picking results by machine and extend the picking catalog for seismic data to the present. We also conduct tomographic inversion for the global mantle to obtain a three-dimensional velocity model for both P and S waves. The new model has a higher resolution, allowing interpretations to understand geodynamics better.
Amplified Midlatitude European Heatwave Trends Linked to Anthropogenic Forced Atlantic Multidecadal Variability-like Warming and Decreased Aerosol Emissions       
Authors: Yin Zejiang , Yang Song , Dong Buwen
Published: March 2024

Midlatitude Europe stands out as a prominent heatwave hotspot, characterized by accelerated upward trends in both summer surface air temperature and heatwave days. Remarkably, these trends surpass the global land average by approximately 2.6 and 2.3 times since 1979. Through dynamic adjustments applied to reanalysis datasets, we found that one-third of these trends resulted from externally forced circulation changes, characterized by a zonal dipolar circulation exhibiting an anticyclonic pattern over Europe. These observed circulation changes are primarily induced by a Rossby wave response triggered by the warming of sea surface temperatures in the North Atlantic, resembling the Atlantic Multidecadal Variability pattern. The ensemble simulations from the sixth phase of the Coupled Model Intercomparison Project indicate that these sea surface temperatures are dominated by the greenhouse gases, with additional contributions from a reduction in aerosols. Additionally, the stronger air temperature response in midlatitude Europe to the reduced aerosols further amplify summer warming, contributing to the rapid increased frequency of heatwave days. These findings offer evidence of important anthropogenic forcing impacts on the rapid surge of heatwaves in Europe, with important implications for potential adaptation strategies and risk management.
Computations to account for composition of the Mediterranean’s Messinian gypsum and halite
Authors: Ryan William , Raad Fadl
Published: March 2024

A simple box model is developed to access the astronomical-modulated exchange of Atlantic seawater with the Mediterranean during the Late Miocene salinity crisis. Key to the calculations is an activity coefficient that reduces the rate of evaporation as salinity increases. The model uses a narrow and shallow portal in order to get salinity to increase to saturation for gypsum, halite and the most soluble potash and magnesium salts. Flow through the Atlantic entry portal changes in direction as climate oscillates from arid to wet during each precession cycle. The model addresses the geochemical riddle of “low salinity gypsum” with calculations showing that rain and rivers supply eight times more water to the Mediterranean brine than seawater. The sulfate isotopes in gypsum come in with the ocean and those in the water of hydration in gypsum from atmospheric precipitation. The evolving chloride, sulfate, potassium and magnesium ions observed from fluid inclusions in gypsum and halite are reproduced in the calculations. The mass of computed halite is approximate to the volume of acoustically-transparent halite observed in reflection profiles. The rates of gypsum, halite and kainite precipitation diminish with time as the result of the decreasing activity coefficient and the associated reduction in the amount of Atlantic inflow. The evaporative model’s reduction in the Atlantic-Mediterranean exchange conforms with the sedimentological and geochemical observations of the gypsum deposits on margins and halite on deep basin floors.
A physics-based approach for simulating future extreme design storms to assess flood risks
Authors: Peleg Nadav , Marra Francesco
Published: March 2024

Design storms are often used to assess flood risks in urban and rural catchments. These synthetic storms are not replicas of real extreme rainfall events but rather simplified simulations of them. Using rainfall intensity-duration-frequency curves, these storms are parameterized to follow extreme rainfall conditions. To construct design storms for the future, these curves must first be recalculated to reflect future climate conditions. We propose a framework for adjusting short-duration intensity-duration curves and storm designs to future climate conditions that only requires projected temperature changes during rainy days. To do this, we first utilize the TENAX (TEmperature-dependent Non-Asymptotic statistical model for eXtreme return levels) model, a novel physically-based statistical model that can estimate future rainfall short-duration return levels. It is then possible to simulate future rainfall intensities (i.e., a design storm) using the duration-intensity curves for the future climate. In most cases, the information from climate models at a daily scale can be used to construct design storms at a sub-hourly scale without any downscaling or data bias corrections. We illustrate our approach by re-parameterizing the Chicago Design Storm (CDS) in light of climate change. Using the city of Zurich (Switzerland) as a case study, we demonstrate how we can calculate changes in the intensity-duration curve for durations ranging from 10 minutes to 3 hours by applying the TENAX model to the 100-year return level. We will then show how we can construct a synthetic 100-year return period design storm using CDS based on the present and future climates, as well as produce flood inundation maps to assess the changes in flood risk in the city.
Predicting Forest Damage in Europe: A Subseasonal-to-Seasonal Forecasting Approach for Hydro-meteorological Drivers
Authors: Rivoire Pauline , Dupuis Sonia , Guisan Antoine , Vittoz Pascal
Published: March 2024

Extreme meteorological events such as frost, heat, and drought can induce significant damage to vegetation and ecosystems. In particular, heat and drought events are projected to become more frequent in a changing climate. On the subseasonal-to-seasonal (S2S) forecasting timescale, skillful forecasts of hydro-meteorological hazards combined with targeted actions can prevent various vegetation damage and large-scale impacts (e.g. agriculture and food security, wildfire risk management, forest management,  biodiversity and flora protection,etc.).We here focus on forest damage in Europe, defined as negative anomalies of the normalized difference vegetation index (NDVI). Compound drought and heat wave events are known to trigger low NDVI events in summer. A dry summer combined with warm and moist conditions during the previous winter can also have a negative impact. However, to our knowledge, there exists no comprehensive study of hydro-meteorological drivers triggering forest damage in Europe. Hence, the goal of our study is a) finding the optimal variables to predict summer forest damage in Europe, and b) assessing the S2S forecast skill of these variables. We develop an automated procedure to systematically identify hydro-meteorological conditions leading to forest damage, up to 18 months prior to occurrence. We train a model using AVHRR remote sensing observation of NDVI for the impact data, and ERA5 and ERA5-Land reanalysis datasets for the explicative variables. These variables include temperature, precipitation, dew point temperature, surface latent heat flux, soil moisture, and soil temperature. To bridge the research gap between the S2S forecasts of hydrometeorological variables and vegetation damage, we assess the forecast skill of variables from the S2S hindcast database of ECMWF identified as responsible for low NDVI events. The idea is to determine to what extent S2S models can predict conditions triggering forest damage, by identifying the sources of predictability or potential need for improvement.
Sensitivity of simulated rain intensity and kineticenergy to aerosols and warm-rain microphysicsduring the extreme event of July 2021 in Belgium
Authors: Van Weverberg Kwinten , Ghilain Nicolas , Goudenhoofdt Edouard , Barbier Matthias , Kostinen Ester , Doutreloup Sébastien , Van Schaeybroeck Bert , Frankl Amaury , Field Paul
Published: March 2024

This paper presents an evaluation and sensitivity analysis of km-scale simulations of the unprecedented extreme rainfall event of July 2021 over Belgium and Germany, with a specific focus on sub-hourly extremes, size distributions and kinetic energy (KE) of rain. These variables are critical for hydrological applications, such as flood forecasting or soil loss monitoring, but are rarely directly obtained from Numerical Weather Prediction (NWP) or climate models. We present an extensive set of simulations exploring sensitivities to realistic variations in a newly implemented double-moment microphysics parameterization in the UK Met Office Unified Model. Most simulations reproduce the overall characteristics of the event, but overestimate the extreme rain rates. The rain rate - KE relation is captured well, despite too large volume-mean drop diameters. Amongst the sensitivities investigated, the representation of the raindrop self-collection - breakup equilibrium and the raindrop size-distribution shape have the most profound impact on the rainfall characteristics. While extreme rain rates vary within 30 %, the rain KE varies by a factor of four between the realistic perturbations to the microphysical assumptions. Changes to the aerosol concentration and the rain terminal velocity have a relatively smaller impact on the extreme rainfall characteristics. However, larger aerosol loading produces slightly smaller domain total rainfall, for which we propose a mechanism involving dynamical impacts of warm-rain suppression. Given the large uncertainties, a continued effort to improve the model physics will be indispensable to reliably estimate sub-hourly rain intensities and KE for direct hydrological applications.
Sensitivity of vegetation structural and physiological information to compound drought and heatwave stress based on Solar-induced chlorophyll fluorescence (SIF)
Authors: Diao Chan , Wu Xiuchen , Li Yang , Zhao Liang
Published: March 2024

Sun-induced chlorophyll fluorescence (SIF) measurements have shown unique potential for quantifying both plant physiological and structural stress under compound drought and heatwave events. However, there is a lack of understanding and well explore of the differences in the sensitivity of vegetation physiological and structural information based on solar-induced chlorophyll fluorescence (SIF) to compound drought and heatwave stresses and the driving mechanisms behind it. The aim of this study was to assess whether SIF-derived physiological information (eΦF) and structural information (NIRvP) could improves the quantification of physiological and structural aspects of vegetation sensitivity to compound drought and heatwave stress at the mid-high latitudes of northern hemisphere by using contiguous sun-induced fluorescence (CSIF) data, respectively. We found that, compared to the vegetation sturctural information (NIRvP), the relative importance of vegetation physiological information (eΦF) to eCSIF variability increases 6.5% to14.8% under compound drought a heatwave stresses in all regions, which confirms the contribution of physiological variation to eSIF. We further demonstrated that vegetation physiological information (eΦF) can better detect compound drought and heatwave stress in humid regions and forest ecosystems, which is mainly driven by physiological (LCC and VCmax) and environmental (VPD and SR) factors; whereas vegetation physiological information (eΦF) and structural information (NIRvP) have similar ability to capture compound drought and heatwave stresses. The lines of evidence suggested that utilizing eΦF for physiological investigations and NIRvP for structural information will contribute to improve our comprehensive understanding of vegetation physiological and structural responses to simultaneous high-temperature and high-drought stresses.
Research on pendulum-type and rotational waves in 2D discrete blocky rock masses with complex hierarchical structures
Authors: Jiang Kuan , Qi Cheng-zhi
Published: March 2024

Rock masses consist of nesting rock blocks with various scales separated by weak structural layers, and their complex hierarchical structures play a significant role in dynamic deformation and stress wave propagation. Based on the Cosserat theory, a dynamic model of pendulum-type and rotational waves in blocks rock mass with complex hierarchical structures is established to determine the influence of hierarchical structures on dynamic deformation. Then, aiming to low-frequency and low-velocity characteristics of pendulum-type waves, dispersion equations of waves are determined and solved in different hierarchical structures based on the Bloch theorem, and furthermore, the dispersion relation and velocity characteristics of waves are investigated. Finally, mechanism of low-frequency characteristics of pendulum-type waves is revealed on the basis of solid energy band theory, and the possibility of pendulum-type and rotational waves inducing rock bursts is discussed based on the research results. It is indicated that ignoring higher-order hierarchical structures of rock masses may underestimate displacement and overall deformation of rock masses, resulting in unsafe numerical results. Under the action of long wave disturbance, for the first mode pendulum-type waves (the acoustic branches), the dispersion is not significant and propagation velocity decreases, and higher-order hierarchical structures inside rock masses hinder the wave propagation. However, the dispersion of other waves (the optical branches) is significant so that they hardly exist and propagate independently. The low-frequency pendulum-type waves are dominant, which have slower attenuation and longer propagation distance than the high-order mode waves and traditional P and S-waves.
Observational Constrained Attribution of Regional Aerosol Simulation Biases in the AerChemMIP models
Authors: Fan Tianyi , Liu Xiaohong , Wu Chenglai , Gao Yi
Published: March 2024

     Regional aerosol simulation biases in climate models have been noted since the CMIP5 era. The biases can cause noticeable error in the radiative forcing estimations. In this research, we investigate the aerosol optical depth (AOD) biases over China from 2002 to 2015 in nine climate models that participate the Aerosol and Chemistry Model Intercomparison Project (AerChemMIP) of CMIP6. The AerChemMIP ensemble mean is high biased over four populated regions in winter and low biased in two populated regions compared to the MODIS satellite retrievals. The patterns of model biases were persistent over years. Large inter-model spread is found in the high AOD regions. We decompose AOD to the product of emission rate, lifetime and mass extinction coefficient such that the AOD biases can be attributed to the errors of each term and their cross error term. The error of each term is analyzed by first regressing to several observable predictors, such as precipitation, Angström exponent, and relative humidity, followed by constraining the predictors by observational or reanalysis data. The results show that error due to emission dominates for many models, followed by lifetime and MEC errors. Furthermore, we argue that for regional analysis, due to imbalance between emission and removal fluxes, the removal/emission ratio should be further constrained by observations. This study provides a diagnosis for climate models to improve their simulation in aerosol loading on regional scale by optimizing the modeling of meteorology as well as aerosol properties and life cycle. 
The role of dip-slip components in creating and maintaining a strike-slip landscape
Authors: Li Yifei , Zhang Huiping , Zhao Xudong
Published: March 2024

Stream-channel offsets are widely used for identifying strike-slip faults and estimating fault slip rates. Most strike-slip faults have the component of dip-slip motion. Here, we used a landscape evolution model to investigate the role of dip-slip in creating and maintaining stream-channel offsets in the strike-slip environment. Our results show that the length of stream-channel offsets is primarily controlled by the vertical slip rate difference (VSRD) between the above fault part and the below fault part. The average cumulative offsets of the stream channels are positively associated with VSRD and are negatively related to the strike-slip rates. The positive VSRD leads to underestimates of offsets by promoting stream capture while the negative VSRD may lead to overestimates of offsets by creating pre-existing offsets and shutter ridges which inhibits stream capture. Our results call for careful studies of surface processes when using stream-channel offsets to infer fault slip and estimate slip rates.
Characteristics of Dissolved Organic Matter Contribute to Geogenic Ammonium Enrichment in Coastal versus Alluvial-lacustrine Aquifers
Authors: Xiong Yaojin
Published: March 2024

Elevated concentration levels of geogenic ammonium in groundwater arise from the mineralization of nitrogen-containing natural organic matter in various geological settings worldwide, especially in alluvial-lacustrine and coastal environments. However, the difference in enrichment mechanisms of geogenic ammonium between these two types of aquifers remains poorly understood. To address this knowledge gap, we investigated two representative aquifer systems in central Yangtze (Dongting Lake Plain, DTP) and southern China (Pearl River Delta, PRD) with contrasting geogenic ammonium contents. The use of optical and molecular characterization of DOM combined with hydrochemistry and stable carbon isotopes has revealed differences in DOM between the two types of aquifer systems and revealed contrasting controls of DOM on ammonium enrichment. The results indicated higher humification and degradation of DOM in DTP groundwater, characterized by abundant highly unsaturated compounds. The degradation of DOM and nitrogen-containing DOM was dominated by highly unsaturated compounds and CHO+N molecular formulas in highly unsaturated compounds, respectively. In contrast, the DOM in PRD groundwater was more biogenic, less degraded, and contained more aliphatic compounds in addition to highly unsaturated compounds. The degradation of DOM and nitrogen-containing DOM was dominated by aliphatic compounds and polyphenols and CHO+N molecular formulas in highly unsaturated compounds and polyphenols, respectively. As DOM degraded, the ammonium production efficiency of DOM decreased, contributing to lower ammonium concentrations in DTP groundwater. In addition, the CHO+N(SP) molecular formulas were mainly of microbial-derived and gradually accumulated with DOM degradation. In this study, we conducted the first comprehensive investigation into the patterns of groundwater ammonium enrichment based on DOM differences in various geological settings.
Integration of health indicators and quantification of benefits from BGS urban interventions
Authors: Huo Wenfei , Temenos Tasos , Boskovic Stanislava , Maksimovic Cedo
Published: March 2024

    With the growing interest in utilizing Blue-green solutions to mitigate the negative impact of urbanization and climate change, and further enhance human health, it becomes essential to comprehensively understand the extent to which BGS influence human well-being through integrating various indicators. Building upon concepts within the existing framework of the Nature-Based solutions to health theory, this study aims to investigate the changes in heart rate among park users and establish connections between these changes and the benefits brought about by urban green spaces, as well as the potential of integrating wearables to quantify the impact of BGS on human health. The research was conducted at the demo site of the HEART project, the Pedion of Areos Park in Athens. The heart rate data of two participants engaged in walking activities within the park were recorded through wearable devices. By analyzing the associations between factors like the Normalized Difference Vegetation Index (NDVI), air pollutants, temperature with heart rate, as well as the complex interplay of various environmental indicators, this study reveals the positive impact of BGS on human health. The outcomes of quantitative statistical analysis indicate that temperature significantly influences heart rate, while the impact of air pollutants on heart rate is not clearly revealed. The result from spatial analysis further confirms a significant correlation between the increase in NDVI and the reduction in Land Surface Temperature (LST), particularly during the spring season. These research findings demonstrate that heart rate can serve as an effective health indicator to quantify the benefits of BGS. While the generalizability of study results might have limitations, it offers insights into the influence of urban green spaces on human health. In the future, with larger sample sizes, diversified datasets such as GeoHealth data with health status, age, and gender, and long-term observations, we can gain a more comprehensive understanding of these positive impacts, thus providing stronger scientific foundations for urban planning and design. 
Ultraviolet radiation enhances the degradation of humus-like substances in DOC in Permafrost streams of the Qinghai-Tibet Plateau
Authors: Li Yuhao , Wang Genxu , Song Chunlin
Published: March 2024

The Qinghai-Tibet Plateau (QTP) is characterized by high-altitude permafrost, intense ultraviolet (UV) radiation, freeze-thaw cycles, and rapid warming. Permafrost thaw can mobilize large quantities of previously frozen organic carbon into aquatic systems where it can be decomposed as greenhouse gases via biodegradation or photodegradation or both. Yet the degradability mechanisms of DOC in permafrost streams of the QTP are not well understood. Here we sampled riverine water in a typical permafrost catchment named Fenghuoshan (FHS) and explored how the concentration, composition, and degradability of DOC respond to microorganisms and UV radiation, by using laboratory incubations and parallel factor analyses. Our results showed that riverine DOC concentrations varied from 3.59 mg·L-1 to 5.61 mg·L-1 during the initial freezing period. After a 28-day microbial incubation in the dark, 53.3% (41.2%~60.8%) of DOC degrades, which underpins the high biodegradability of DOC. In a 3-day comparison experiment, 30.6% (22.4%~36.7%) of DOC is degraded by UV light after 72h abiotic photodegradation, 1.81 (1.14~2.43) times higher than microbial decomposition. Interestingly, the degradation of DOC rises to 42.9% (32.8%~53.8%) after a microbial incubation under UV radiation, 2.53 (1.85~3.11) times higher than microbial decomposition alone. Spectral analysis showed that microorganisms and UV radiation preferentially degrade non-aromatic compounds and small molecules. DOC components change negligibly during microbial incubations. In contrast, the contribution of terrestrial organic matter and autochthonous dissolved organic matter increased, while the degree of humification and the content of humus-like substances significantly reduced during UV radiation incubations. Overall, these results suggested that UV radiation degrades riverine DOC more intensely than microorganisms. The humus-like substances of DOC are preferentially degraded by UV radiation. Our findings suggest that sunlight is a crucial regulator for DOC degradation in permafrost streams of the QTP.
Imaging of Crust and Lithospheric Mantle of the Incipient Okavango Rift Zone: Implications on the Rifting Mechanism
Authors: Wang Tuo , Chen Ling , Gao Stephen S. , Liu Kelly H. , Yu Youqiang , Yu Zhichao , Wang Xu
Published: March 2024

The Holocene Okavango Rift Zone (ORZ) marks the southern terminus of the Western Branch of the East African Rift System. Detailed knowledge of the crustal and lithospheric mantle structure of the ORZ is essential to decipher the rifting mechanism and nature of the lithosphere of this incipient continental rift. A 3-D shear wave velocity model from the surface to 160-km depth is constructed by jointly inverting the Rayleigh wave phase velocity dispersion and receiver function data through a non-linear Bayesian Monte-Carlo algorism. The crustal thickness estimates from our new velocity model generally agree with previous receiver function investigations of the region. The crust beneath the ORZ is thinned compared with the cratonic regions to both sides of the rift, suggesting a certain degree of continental stretching. Our velocity model also reveals two low velocity anomalies in the crust and upper mantle beneath the incipient rift, respectively. The shallow low velocity anomaly is mainly confined in the upper and middle crust, and the deeper low velocity anomaly extends from the Moho to at least 160 km depth, with a high-velocity lower crust (~4.0 km/s) in between. Although the two low velocity anomalies are probably both caused by rift-related decompression melting, the structural feature imaged suggests that they are generated separately and individually. Based on our observations, we propose that thermal upwelling and decompression partial melting in the upper mantle of the ORZ have a limited contribution to the stretching and thinning of the crust during the initiation of the continental rifting. The crustal rifting could be induced by an intra-plate relative motion between the South African block and the rest of the African continent along a pre-existing weak zone.
Promoting soil carbon sequestration by diversifying tree species
Authors: Li Dejun , Qian Zhongyao , Duan Pengpeng , Fang Yuantian
Published: March 2024

Forests cover about 30 % of the global land surface and store 861 ± 66 Pg C with 44 % being stored as soil organic carbon (SOC). Considering the huge amount, the variation of forest SOC would pose a considerable impact on C cycle-climate feedbacks. SOC pool is determined by the balance of C inputs mainly as plant detritus and C outputs via SOC decomposition, so that factors which affect C inputs or outputs may subsequently alter SOC pool. Cumulative evidence shows that increasing tree species diversity benefits SOC accumulation, but the underlying mechanisms remain poorly understood. We utilized a natural gradient of tree species diversity, and explored the impacts of tree species diversity on SOC dynamics in a subtropical forest. Tree species diversity increased microbial C growth and C use efficiency (CUE). Multiple analyses revealed that changes in microbial traits especially microbial life history strategies and substrate quality were mainly responsible for the increase of CUE in responsible for increasing tree species diversity. The increased CUE resulted in stimulated microbial biomass C, which is the precursor of microbial residue C. Meanwhile, increasing tree species diversity improved the mineral protection of microbial residue C and benefited its accumulation. The level of lignin as indicated by lignin phenols increased under higher tree species diversity due to stimulated plant detritus input, mineral protection and suppressed lignin decomposition by microbes. The increase of both microbial and plant residue C ultimately led to enhanced SOC pool under higher tree species diversity. Additionally, temperature sensitivity of SOC decomposition remains unchanged, priming effect of SOC decomposition decreases, and soil multifunctionality increases along with increasing tree species diversity. These findings suggest that diversifying tree species during afforestation would gain more than SOC accrue.
Using Bayer red mud as an alternative activator in hybrid alkali-activated cement for cemented paste backfill: Experimental investigation and life cycle assessments
Authors: Feng Yan , Zhao Cunyu , Zhang Qinli , Wang Daolin
Published: March 2024

Ordinary Portland Cement (OPC) is the most widely used cementitious material in cemented paste backfill at present. However, OPC production consumes massive energy and is one of the main contributors to greenhouse gas emissions. Hybrid alkali-activated cement (HAAC) is a promising alternative to Ordinary Portland Cement (OPC), mainly consisting of supplementary cementitious materials (SCMs), OPC, and alkali activators. This innovative solution not only reduces energy consumption but also mitigates carbon footprint compared to OPC production. Moreover, it is worth noting that the production process of widely used commercial alkali activators, including sodium hydroxide and sodium silicate, is associated with notable energy consumption and environmental pollution. Therefore, addressing these concerns is essential for enhancing the sustainability of HAAC and making it an environmentally friendly choice in cemented paste backfill.Red mud (RM) is a by-product generated by the Bayer process during the production of alumina from bauxite, which is a potential alternative to commercial alkali activators due to its high alkalinity. The experimental results show that the cemented paste backfill with RM-NaOH activated slag cement exhibits higher compressive strength than that with OPC or NaOH activated slag cement as binders in different curing ages. By comparing the Life Cycle Assessment (LCA) results, the RM-NaOH activated slag cement shows reductions mainly in the environmental impact categories of terrestrial acidification potential (TAP), fossil depletion potential (FDP), ozone depletion potential (ODP), and global warming potential (GWP). The total environmental impact of RM-NaOH activated slag cement is reduced by 13.67% compared to OPC, indicating that the production of HAAC with RM as the primary activator would significantly decrease the environmental effect of OPC manufacturing.
Evaluation of MODIS LST products over the Tibetan Plateau and plain areas with in situ measurements
Authors: Qi Yuting , Zhong Lei , Ma Yaoming , Fu Yunfei , Wang Zixin , Li Peizhen
Published: March 2024

Land surface temperature (LST) is a crucial physical parameter for hydrological, meteorological, climatological, and climate change studies. To encourage the use of satellite-derived LST products in a wide range of applications, providing feedback on product performance over regional and global scales is an urgent task. However, considering that the uncertainty of newly released LST products is still unclear, it is urgently necessary to perform a comprehensive validation and error analysis, especially in areas with special geographical and weather conditions such as the Tibetan Plateau (TP). In particular, fewer studies have been concerned with the degraded LST retrieval accuracy over the TP because of the sparse ground measurements. In this study, MODIS LST products (C6) were comprehensively evaluated based on independent ground observation systems with different atmospheric and LST conditions. The in situ measurements collected from the TORP and SURFRAD systems are located on the North American Plain and the TP, respectively, incorporating various land cover types, including barren land, grassland, cropland, shrubland and sparse and dense vegetation, among others. Prior to the validation, LST products with different spatial resolutions were compared to ensure the spatial representativeness of ground-based measurements at satellite pixel scale. The evaluation results indicated that relatively high-quality in situ LST can be obtained during nighttime with relatively homogeneous spatial distribution. Compared with the North American Plain (with a mean RMSE of 1.56 K), MODIS LST retrieval has larger discrepancies (mean RMSE of 2.34 K) over the TP with complex terrain and variable weather. Various factors affecting LST retrieval accuracy were analyzed, which were categorized into 1) the simulated atmospheric and surface temperature condition settings, 2) the input data uncertainty, and 3) others. Among them, the emissivity determination is the primary source of the uncertainty in the generalized split-window algorithm, where the overestimated emissivity causes an underestimation of LST. It is expected to develop new LST retrieval algorithm to meet the quality specifications of users over the TP. Overall, this study identifies critical further research needs and improve the understanding of LST product performance under complex circumstance.