bluuebunny/crossref_metadata_2025 huggingface dataset:
Databases for China-Indochina Paleogeography
Authors: Ogg James , Zhang Linna , Hou Hongfei , Dong Bui , Hou Mingcai , Fan Junxuan , Du Wen , Zhang Sabrina , Li Haipeng
Published: February 2023

            Building paleogeographic maps requires team efforts to compile databases of regional sedimentary and volcanic facies, to validate and update information, and to develop visualization and computer projection methods. We have worked with experts on regional geologic systems to assemble cloud-based detailed lexicons of all geologic formations within China-Indochina regions (ca. 3000 formations as of March 2023; http://chinalex.geolex.org; vietlex.geolex.org; thailex.geolex.org). A parallel program through the past decade by the Geobiodiversity Database (GBDB) team has completed a detailed grid of outcrops and borehole stratigraphic-biostratigraphic columns for much of China (http://www.geobiodiversity.com). The GBDB had initially focused on the Early Paleozoic; for example, the Ordovician portion for the South China plate contains detailed stratigraphic information at biozone level from 750 exposed sections. The user interfaces for both projects include various search options, and map or stratigraphic navigation. Both of these database projects are now components of the paleogeography program of the IUGS Deep-time Digital Earth system (deep-time.org).            These databases enable display of all lithologies of a desired time horizon onto the modern geography or onto modeled plate reconstructions of that geologic age. For the interlinked Lexicon databases of China-Indochina (and the Indian Plate), the auto-merged output provides a visualization of all formations as polygons filled with a colored generalized facies pattern projected onto the dispersed Asian plates (Du et al., Geoscience Data Journal, 2023). The GBDB database produces very detailed isopach and paleogeographic depositional-facies reconstructions, for example the paleogeography and sediment patterns of South China for each Ordovician stage (Zhang, L.N., et al., Earth-Science Reviews, 2023).            The main coordinators for the China Lexicon database include Gao Linzhi (Precambrian), Shanchi Peng (Cambrian), Xiaofeng Wang (Ordovician-Silurian), Hongfei Hou (Devonian), Xiangdong Wang (Carboniferous), Rennong Wang (Permian), Jinnan Tong (Triassic), Jingeng Sha (Jurassic), Wan Xiaoqiao (Cretaceous) and Deng Tao (Cenozoic); and the details will be published in a forthcoming Stratigraphic Lexicon of China. For Vietnam, the team at Vietnam National University provided extensive updates and GeoJSONs to their previous published-book compilation by Tran Van Tri and Vu Khuc (Editors, 2011; Geology and Earth Resources of Viet Nam, General Dept. of Geology and Minerals of Viet Nam).
Advancing Ice-jam Flood Risk: Integrating Dynamic Adaptive Behavior into Agent-based Model of Fort McMurray
Authors: Ghoreishi Mohammad , Das Apurba , Lindenschmidt Karl-Erich
Published: February 2023

Human behaviors have changed as ice-jam flooding has become more prevalent, impacting both flood hazard and vulnerability as a function of flood risk. These dynamic adaptations can be developed by both governments (e.g., artificial breakup and dike installation) and individuals (e.g., flood-proofing and elevating houses). The interaction between these top-down and bottom-up measures provides a complex socio-hydrological system. However, the traditional assessment of ice-jam flood risk lacks an appropriate consideration of evolving human behaviors and their interactions with static assumptions on human adaptations. We build an agent-based model to assess the ice-jam flood risk with top-down and bottom-up adaptive strategies (artificial breakup and flood-proofing). The individuals’ behaviors are influenced by the possible reduction in flood risk at the individual level by artificial breakage over time. Also, the government’s behavior is influenced by the possible reduction in total flood risk by the dynamic adaptive behavior of individuals (flood-proofing). Thus, micro levels’ behavior can dynamically lead to macro phenomena, and macro phenomena define micro levels’ behavior over time. This model is applied to Fort McMurray along the Athabasca River, Canada, with a long history of ice-jam flooding. Also, we perform a variance-based global sensitivity analysis to investigate the individual effect of model factors and their joint effects on ice-jam flood risk. The results show that although the artificial breakage by the government leads to a regime shift and a considerable decrease in the ice-jam flood risk, it decreases the number of the newly adapted residents to flood-proofing and the role of residents in ice-jam flood risk. This study can provide a good understanding of the important role of dynamic adaptive behavior in ice-jam flood risk and pave the way for better Building flood resilience. 
Updated PSC climatology based on CALIOP measurements from 2006-2023
Authors: Pitts Michael , Poole Lamont
Published: February 2023

After more than three decades of research, the roles of polar stratospheric clouds (PSCs) in stratospheric ozone depletion are well established. Heterogeneous reactions on PSCs convert the stable chlorine reservoirs HCl and ClONO2 to chlorine radicals that destroy ozone catalytically.  PSCs also prolong ozone depletion by delaying chlorine deactivation through the removal of gas-phase HNO3 and H2O by sedimentation of large nitric acid trihydrate (NAT) and ice particles. A substantial recovery of the ozone layer is expected by the middle of this century with reduced global production of ozone depleting substances in accordance with the Montreal Protocol and subsequent amendments.  But as climate changes, leading to a colder and perhaps wetter stratosphere and upper troposphere, reliable model predictions of recovery of the Antarctic ozone hole and of potentially more severe ozone depletion in the Arctic are challenging.  This is due both to a lack of detailed understanding of the underlying physics and the fact that many global models use simple parameterizations that do not accurately represent PSC processes.A more complete picture of PSC processes on vortex-wide scales has emerged from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) instrument on the CALIPSO satellite that has been observing PSCs at latitudes up to 82 degrees in both hemispheres since June 2006.  The CALIOP Version 2.0 (v2) PSC algorithm was recently developed to address known deficiencies in previous algorithms and includes additional refinements to increase the robustness of the inferred PSC composition. In this paper, we present an updated PSC reference data record and comprehensive climatology constructed by applying the v2 algorithm to the more than 17-year CALIOP spaceborne lidar dataset.  In addition, we will examine the potential impact of aerosol and water vapor injections into the stratosphere from the January 2022 Hunga Tonga eruption on PSC occurrence in both the Arctic and Antarctic regions. 
Eruption Parameters Measured In-flight during the 2022 Icelandic Meradalir Eruption
Authors: Tisdale Caroline , Houghton Bruce , Sigurlína Pálmadóttir Jóna , Thordarson Thorvaldur
Published: February 2023

The 2022 Icelandic eruption of Meradalir along the Reykjanes Peninsula, was captured via videography in exceptional detail over much of its 18-day duration. This eruption, like the 2021 Fagradalsfjall eruption, did not pose significant threat to human life or infrastructure. However, many lava-fountaining eruptions elsewhere of similar character (2018 Lower East Rift Zone, Hawaii & 2021 Cumbre Vieja, La Palma, Spain) have caused substantial destruction. Understanding eruption dynamics at these volcanoes is critical for fine-tuning of hazard and risk assessment. With the increasing use of high-speed/resolution cameras in field settings, we are able to quantify in-flight parameters such as particle size and particle exit velocities, rather than having to solely rely on deposit characteristics from samples collected once an eruption has ceased. This is an important development because ground samples can be rapidly buried or reworked and are subject to additional fragmentation during transport and when hitting the ground. The abundance of quantitative information we can obtain from this, coupled with qualitative observations, has allowed us to deepen our understanding of processes of weak explosive eruptions.
Constraining subglacial geology using mutual information inversion of gravity and magnetic data in the Wilkes Subglacial Basin and Transantarctic Mountains of East Antarctica
Authors: Lowe Maximilian , Jordan Tom , Moorkamp Max , Ebbing Jörg , Ruppel Antonia , Koglin Nikola , Green Chris , Lösing Mareen , Larter Robert
Published: February 2023

The Wilkes Subglacial Basin hosts potentially the largest unstable sector of the East Antarctica Ice Sheet due to the depth of the ice bed below sea level. Ice covering such basins poses a potentially high, but poorly constrained risk for future sea-level rise, as it is more vulnerable to melting by warming of the surrounding ocean. Such melting could potentially trigger mechanisms of unstable retreat. The neighbouring Transantarctic Mountains are the largest non-contractional mountain range on Earth. Traditionally, the Transantarctic Mountains are viewed as dividing the ancient East Antarctic craton from the younger West Antarctic Rift system. However, petrological samples and previous geophysical mapping suggest that the craton boundary is further west, following the western edge of the Wilkes Subglacial Basin. Subglacial geology influences geothermal heat flow and bed roughness, and therefore to better understand the past, present and possible future behaviour of the East Antarctic Ice Sheet improved understanding of the subglacial geology on which it flows, especially in the Wilkes Subglacial Basin and Transantarctic Mountains region, is important.We present a new 3D crustal model of the Wilkes Subglacial Basin and the Transantarctic Mountains based on joint inversion of airborne gravity and magnetic data using the mutual information inversion algorithm incorporated in the software JIF3D. Our model shows a large intrusive body located in the interior of the Wilkes Subglacial Basin and suggests a tectonically complex area west of the Basin, which could potentially indicate the transition zone at the margin of the Terre Adélie Craton. Geological units are inferred by clustering of inverted susceptibility and density distribution and are validated against sparse petrological samples from the Transantarctic Mountains region and along the George V Land and Terre Adélie coasts. Our inferred crustal properties model can provide crucial insight into the heterogeneity of subglacial geology in terms of thermal conductivity and crustal heat production, which could influence the geothermal heat flow in this area and therefore make the overlying ice sheet more vulnerable than commonly thought. 
Two-Channel, Fast Time-Response CAPS-Based NOx Monitor
Authors: Freedman Andrew , Roscioli Joseph , Moul Benjamin , Onasch Timothy
Published: February 2023

We have developed a turnkey, fast response two-channel NOx monitor (NOx =NO + NO2) which provides  simultaneous measurements of both NOx and NO2 and thus NO by subtraction.  The NOx channel employs a carefully controlled concentration of photolytically-produced ozone (O3) to convert NO into NO2.  The monitor can measure NO2 and NOx with an accuracy of better than 5% and precision of < 0.2 ppb (1s, 1s) with <1 second physical time constant in each measurement channel.  The monitor is based on Aerodyne Research’s patented CAPS (Cavity Attenuated Phase Shift) technology previously employed to measure NO2concentrations, aerosol optical extinction and aerosol single scattering albedo. A CAPS-based NO2 monitor utilizes a light-emitting diode (LED) as a light source (450 nm for the NO2 channel and 405 nm for the total NOx channel) and a sample cell incorporating two high reflectivity mirrors; a vacuum photodiode is used to detect the light emitted from the cell. The square wave modulated light from the LED passes through the absorption cell and is detected as a distorted waveform which is characterized by a phase shift with respect to the initial modulation.   The amount of that phase shift is a function of fixed instrument properties - cell length, mirror reflectivity, and modulation frequency– and of the presence of variable concentrations of nitrogen dioxide.  The mixing ratio is calculated from the value of the cotangent of the phase shift, the speed of light, LED modulation frequency and the absorption coefficient of NO2.  The use of 405 nm detection in the total NOx channel greatly reduces the possible interference caused by the presence of several ppm of O3 in the sample flow.We present data from an intercomparison of the NOx monitor with Aerodyne TILDAS monitors measuring both NO and NO2.  The TILDAS monitors utilize infrared diode lasers to probe individual ro-vibrational absorption lines and are considered the “gold standard” for measuring concentrations of small molecules.  The monitors were deployed on the Aerodyne Mobile Laboratory during the MOOSE (Michigan Ontario Ozone Source Experiment) campaign in late 2021.  The figure presented below compares the measurement of both NO2 and the sum of NO+NO2 measured by the TILDAS monitors compared with that obtained by the CAPS NO monitor at 1 second resolution.  Note the excellent agreement with respect to both magnitude and time resolution.  Long term comparisons indicate that correlation coefficients at 1 second  resolution approach 1. 
Determination of optimal number of Soil moisture and electrical conductivity sensors deployment in field
Authors: Chandel Aman , Swami Deepak
Published: February 2023

The conventional methods used for determination of soil moisture and electrical conductivity are tedious and laborious. It leads to the imperative need to use soil moisture and electrical conductivity sensor and logging to collect the real time data set. These devices detect the change in saturation and salinity levels of the soil. This data has huge application in the precision agriculture, optimised irrigation, soil moisture monitoring and fertilizer application etc. However, the optimal number of sensors and the associated error curtailment is of great significance but cumbersome. Therefore, this study proposes a benchmarking approach to identify the optimum number of sensors required for field scale operations based on feedback from sensor performance under varying range of working conditions such as saturation percentage, salinity and temperature. The experiments were conducted in controlled temperature conditions varying from 2 to 45˚C. The sensor arrays from minimum of three to nine were grouped to collect moisture, salinity and temperature data and associated error. Overlaying the full-scale error band and 95% confidence interval produced by the sensitivity analysis used in determining the outliers. Analysing the sensitivity plots for various sensor combinations suggested seven sensors as the optimum number to minimise the error. Further, these sensors were deployed in gridded heterogenous medium tank for continuous datalogging to study the variation in salinity.
A new technology for green urban construction：using sand-based concrete permeable brick to conserve rainwater in the urban area
Authors: Xu Xiangzhou , Gao Hang
Published: February 2023

Abstract Rainwater management is an important solution to climate change and flood risk reduction in the urban area. This study presents a nature-based solution to conserve rainwater in the urban area: a kind of permeable brick made of desert sand, of which compressive strength is intensive, water permeability is high, and fabrication cost is low. The desert-sand bricks presented here will be more in line with both the environmental and economic aims of developing countries. The compressive strength is one of the most important factors that impact the service life of permeable bricks, while the fabrication cost is one of the key reasons influencing the market share of permeable bricks. In this study, the minimum compressive strength of the desert-sand brick is 34.9 Mpa, which has exceeded the requirements of the standard JC/T 945-2005. Moreover, the mean and maximum compressive strengths of the desert-sand bricks are 69.6 and 102.8 Mpa, which are 2.3 and 3.4 times of the strength required by the standard JC/T 945-2005, respectively. The fabrication cost of the water-permeable brick designed by the authors is only 12 US dollars/m2, which is much lower than that of the sand-based permeable bricks that already exist in the market. Additionally, more ecological benefits could be gotten because the main aggregate in the sand-based permeable bricks is the desert sand rather than river sand. The results show that the kind of permeable brick can render substantial economic benefits and ecological improvements.Keywords: Urban area; Water conservation; Permeable brick; Desert sand
What are coarse dust aerosols, and how do they impact the Earth's climate system?
Authors: Adebiyi Adeyemi , Kok Jasper , Murray Benjamin , Ryder Claire , Stuut Jan-Berend , Kahn Ralph , Knippertz Peter , Formenti Paola , Mahowald Natalie , Perez García-Pando Carlos , Klose Martina , Ansmann Albert , Samset Bjørn , Ito Akinori , Balkanski Yves , Di Biagio Claudia , Romanias Manolis , Huang Yue , Meng Jun
Published: February 2023

Mineral dust is an important aerosol specie in the atmosphere that impacts the Earth’s climate system through its interactions with radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. Because dust sizes span more than three orders of magnitude in diameter and dust properties are size-dependent, most previous studies separate dust particles into different classes – broadly defined as fine and coarse dust – which could produce distinct impacts on the Earth system. However, there are general inconsistencies in the terminology, the diameter boundaries, and diameter ranges currently attributed to dust size classes across the literature. As part of a comprehensive review of coarse dust recently completed, we propose, with justification, a new uniform classification that defines coarse and super-coarse dust as particles between 2.5 - 10 µm and 10 - 62.5 µm in diameter, respectively. In addition, we will show several lines of observational evidence that indicate coarse and super-coarse dust particles are transported much farther than previously expected and that the abundance of these particles is substantially underestimated in current global models. Despite the limitations of representing coarse and super-coarse dust aerosols in models, we will highlight their unique impacts on several aspects of the Earth's climate system.
Diagnostic Analysis of the Physical Processes Underlying theLong-Duration O/N2 Depletion During the Recovery Phase ofthe 8 June 2019 Geomagnetic Storm
Authors: Yu Tingting , Wang Wenbin , Ren Zhipeng , Cai Xuguang , Liu Libo , He Maosheng , Pedatella Nicholas , Zhai Changzhi
Published: February 2023

A thermospheric O and N2 column density ratio (ΣO/N2) depletion with long-duration (>16 hr) was observed by the Global-scale Observations of the Limb and Disk at the Atlantic longitudes (75W–20W) and middle latitudes (20N–50N) during the recovery phase of the 8 June 2019 geomagnetic storm. The National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) simulations reproduced the ΣO/N2 depletion patterns with a similar magnitude, and indicated that the composition recovery at middle latitudes began several hours after the beginning of the recovery phase of the geomagnetic storm. The TIEGCM simulations enable quantitative analysis of the physical mechanisms driving the middle-latitude composition changes during the storm recovery phase. This analysis indicates that vertical advection and molecular diffusion dominated the initial recovery of composition perturbations at middle latitudes. Horizontal advection was also a main driver in the initial recovery of composition, but its contribution decreased rapidly. In the late recovery phase, the composition recovery was mainly determined by horizontal advection. In comparison, vertical advection and molecular diffusion played a much less important role.
Coupled methane clumped isotope and propane position-specific isotope analyses indicate significant methane contribution from biodegradation of hydrocarbons in terrestrial methane seeps located at central Japan
Authors: Zhang Naizhong , Jajalla Mellinda , Nakagawa Mayuko , Taguchi Koudai , Gilbert Alexis
Published: February 2023

Terrestrial hydrocarbon seeps are widely distributed in oil/gas field. To constrain the sources and post-generation processes occurring in these seeping gases, various geochemical approaches, such as chemical and stable isotope composition (δ13C and δD) of hydrocarbons have been extensively used. However, the interpretation can be ambiguous due to the overlap of signatures when using these approaches only1. Some recently developed analytical techniques, such as methane clumped isotope analysis (Δ13CH3D and Δ12CH2D2)2-4 and propane position-specific isotope analysis (PSIA)5 may provide new clues to improve our understanding of the origin and fate of hydrocarbons.In this study, we focus on gas samples from different gas seeps and mud volcanos in central Japan collected from 2019 to 2022, where hydrocarbons were considered mainly originating from thermal cracking of organic matter6. Gas compositions, bulk stable isotopes of hydrocarbons and associated CO2, clumped isotopes of methane, PSIA of propane and other geochemical parameters have been studied. Coupled methane clumped isotope signatures and propane PSIA information provide direct evidence of secondary microbial methane formation associated with biodegradation of non-methane hydrocarbons. The contribution of secondary microbial methane in different seeps/mud volcanos and its temporal changes are also discussed by a mixing model integrating all these isotope information, which provides valuable constraints on methane sources in terrestrial seeps.References: [1] Milkov and Etiope, 2018, Org. Geochem.; [2] Stolper et al., 2014, Geochim. Cosmochim. Acta.; [3] Stolper et al., 2014, Science; [4] Young et al., 2017, Geochim. Cosmochim. Acta.; [5] Gilbert et al., 2019, Proc. Natl. Acad. Sci. U.S.A.; [6] Etiope et al., 2011, Appl. Geochem.
Contributors to the Elevation-Dependent Warming over the Tibetan Plateau in the CORDEX-EA-II simulations
Authors: niu xiaorui
Published: February 2023

To explore the driving mechanisms of elevation-dependent warming (EDW) over the Tibetan Plateau (TP), the output from a suite of numerical regional climate models (RCMs) under the Coordinated Regional Climate Downscaling Experiments-East Asia (CORDEX-EA-II) project is examined. Results show that all RCMs can broadly capture the observed temperature distributions over the TP with consistent cold biases, and the spread in temperature simulations could to a large extent be explained by their spreads in the surface albedo feedback (SAF). The simulated EDW during winter is mainly caused by the SAF, and the clear-sky downward longwave radiation (LW) plays a secondary role in shaping EDW. Further analysis suggests that a marked EDW signal over the TP is simulated under the Representative Concentration Pathway emission scenario 8.5 (RCP8.5) for all seasons, particularly in autumn, and the SAF is also the primary contributor to EDW and acts as the main source of uncertainty in EDW projections among RCMs. The LW is the dominant factor in regulating the surface air temperature change over the TP, and its contribution to EDW is model-dependent. Furthermore, the structure and magnitude of projected EDW are sensitive to the RCM physics and driving GCM, as they can alter the projections of snow cover and albedo, which modulate the simulated SAF and its effect on EDW.
Modeling risk to infrastructure due to episodic debris fan aggradation
Authors: Chiu Yuan-Hung , Stark Colin P. , Capart Hervé
Published: February 2023

In many mountain valleys, communities and infrastructure are exposed to high risks of damage due to debris fan aggradation. To assess such risks, two questions must be addressed: (1) What will be the extent and thickness of deposition over the fan for a given volume of debris delivered from the upstream catchment? (2) How large could debris flow volumes be for a single event or a sequence of events? In this contribution, we propose a methodology to address both questions. Its first component is a simplified model of debris fan morphology, based on assuming a fan-slope-distance relationship along paths affected by topographic obstacles like steep valley sides. Using a computationally efficient algorithm, this model can be used to reconstruct past fan volumes from terrace remnants resolved on high resolution DEM topography, and to simulate large numbers of possible future events. Its second component is a stochastic model for the evolution of fan volume framed as a form of random walk. To take into account the episodicity of debris delivery, we model this random walk as a gamma-subordinated Wiener process aka a variance-gamma process. To calibrate the model parameters, we exploit both short-term and long-term data: for the slope-distance relationship, topographic data from recent and Holocene debris-fan remnants; for the stochastic process parameters, reconstructed fan-volume changes associated with recent flood events and with older radiocarbon-dated fan surfaces. We illustrate the approach with an application to the Laonong River in southern Taiwan. In this valley, an important roadway link has been repeatedly damaged by debris-flow aggradation. To guide road and bridge reconstruction, it is essential to assess fan aggradation risk for different design alternatives on a decadal time scale or more. The model provides a basis for optimizing the layout and height of such infrastructure.
Synoptic water isotope surveys to understand the hydrology of large intensively managed catchments
Authors: Chen Ke , Tetzlaff Doerthe , Liu Guodong , Soulsby Chris , Goldhammer Tobias
Published: February 2023

Precise knowledge of hydrological processes across large scale catchments is crucial to sustainably meet the growing water demand and improve water management strategies in cities. However, it has been always a major challenge to comprehensively understand the hydrology of a large catchment due to the spatial heterogeneity of climate, topography and anthropogenic activities. Combining tracers with hydroclimatic records, this study used seasonal synoptic surveys in 2021 to better understand the water cycling, storage and losses of the intensively managed 10,000 km2 catchment of the River Spree in Berlin, Germany. Apart from the upper headwaters, the hydrology of the Spree is heavily regulated by reservoir releases, pumped minewater discharges, engineered flows in wetlands and lakes, water abstractions and urban drainage. Moreover, the catchment is drought-sensitive with potential evapotranspiration often exceeding annual rainfall. This is reflected in the spatial and temporal variability of the isotopic composition of river water. In the steeper, upper headwater areas, the river is dominated by groundwater sources but showing evident influence by rainfall in winter, with a “flashy” rainfall-runoff response. However, flows in the middle part of the catchment have enhanced baseflows and attenuated high flows from extensive reservoir and pumped minewater releases. The reservoir waters are isotopically heavier and reflect the effects of open water evaporation. Fractionation effects strengthen downstream as managed wetland areas and natural lakes further enhance evaporation and attenuate flows. Our estimations on evaporation losses also show that the mine water pumping, water abstractions and wastewater additions largely contribute to the catchment water balance and therefore have pronounced impacts on water evaporations. Seasonally, the effects of evaporation on the isotopic composition of the lower river network are strongest in summer and autumn, though they remain in winter and spring, indicating a large memory effect due to long mean travel times within the river system. Tritium variability along the river reflects inputs of younger and older water in different parts of the river system; though the influence of pumped groundwater means that the mean age of stream water in the lower river is likely to be >50 years. Isotope studies at large scales play a valuable role to in better understanding the hydrology of this complex, heavily modified river system and provide an evidence base for more sustainable management of the potentially fragile water resource situation in the future.
Validation of MVT bias correction in dynamical downscaling simulations for climate extreme
Authors: Zhang Meng-Zhuo , Han Ying , Xu Zhongfeng , Guo Weidong
Published: February 2023

Dynamical downscaling is a widely-used approach to generate regional projections of future climate extremes at a finer scale. Previous studies indicated that the global climate model (GCM) bias correction method prior to dynamical downscaling can improve the simulation of the climate extreme to a certain extent. Recently, a new bias correction method termed MVT was developed. Note that this method did not correct the GCM biases of the climate extreme event explicitly. In this study, we evaluate the MVT method in terms of various climate extreme events through three dynamical downscaling simulations over Asia-western North Pacific with 25 km grid spacing throughout 1980–2014, and further investigate to what extent and how this bias correction method can improve the simulation of downscaled climate extreme events. The dynamical downscaling simulations driven by the original GCM dataset derived from the MPI-ESM1-2-HR (hereafter WRF_GCM), the bias-corrected GCM (hereafter WRF_GCMbc) are validated against that driven by the European Centre for Medium-Range Weather Forecasts Reanalysis 5 dataset, respectively. The results suggest that compared with the WRF_GCM, the WRF_GCMbc shows more than 26% decrease in root mean square errors of the precipitation and temperature extreme indices, and even 61% out of seasonal extreme indices show more than 50% reduction. Such improvements in the WRF_GCMbc are primarily caused by the correct simulation of the large-scale circulation due to the GCM bias correction. The large-scale circulation in turn improves the simulation of the precipitation and cloud by the water vapor transport and further improves the simulation of the 2m temperature by the radiation process and the surface energy balance, which contribute to the better simulation of the precipitation and temperature extreme indices.
Electron acceleration mechanisms at Earth’s quasi-perpendicular bow shock
Authors: Lindberg Martin , Vaivads Andris , Raptis Savvas , Karlsson Tomas
Published: February 2023

We use the Magnetospheric Multiscale mission to observe electron acceleration events at Earth’s quasi-perpendicular bow shock. Acceleration mechanisms up to mildly relativistic electron energies are investigated in order to provide more insight into the long-standing injection problem. The events are chosen for their diversity in observed high energy electron flux and shock angle, θBn, enabling the Stochastic Shock Drift Acceleration theory to be further tested for different shock parameters. An alternative acceleration mechanism is also presented. The electron acceleration region of this unusual event is associated with a decrease in wave activity, inconsistent with common electron acceleration mechanisms such as Diffusive Shock Acceleration and Stochastic Shock Drift Acceleration. The energetic electron population is shown to have a bi-directional pitch-angle distribution, indicating parallel heating along the magnetic field lines.We propose a two-step acceleration process where energetic field-aligned electrons originating from the electron foreshock act as a seed population further accelerated by a shrinking magnetic bottle process. Furthermore, we present evidence for electron pitch-angle scattering at the shocks and discuss its importance and different roles for the different electron acceleration mechanisms mentioned above.
Digital close range photogrammetry for the study of soil erosion at flume scale
Authors: Shi Haijing , Guo Minghang , Shui Junfeng
Published: February 2023

Soil erosion is a continuous process of detachment, transportation, and deposition of soil particles. Obtaining accurate descriptions of soil surface topography is crucial for quantifying changes to the soil surface during erosion processes. A digital close range photogrammetric observation system based on wireless networking technology was explored and established in this study. Through wireless networking, multi-cameras were concurrently controlled, solving the problems of synchronous acquisition of underlying digital image, big data transmission and storage. Image sensors collected data in parallel based on network command, and noise on the images such as raindrops was eliminated based on the K-means clustering algorithm by serialization technology during data acquisition. After parallel preprocessing, high density 3D point clouds and digital elevation models (DEMs) were reconstructed. The evolution of soil surface topography was dynamically monitored by instantaneous image acquisition at different time intervals during ongoing rainfall. The results showed that the measurement precision of the established system could reach a sub-millimeter level with the minimum single measurement error being 0.0069 mm. In addition, based on the DEM generated from digital point clouds, the amount of soil erosion in different topographic positions within various time periods was calculated. The digital photogrammetric observation methods explored in our study provide a reliable way to monitor soil erosion processes, especially under rainfall conditions. This approach can accurately resolve the evolution of the underlying surface soil erosion, which is of great importance in understanding soil erosion mechanisms.
Graph-based method for analysis of multiple pipe failures in water distribution networks
Authors: Satish Rahul , Lindenthale Thomas , Dastgir Aun , Hajibabaei Mohsen , Oberascher Martin , Sitzenfrei Robert
Published: February 2023

Critical infrastructures such as water, power, telecommunications, and transportation systems are an important part of human life in an urban environment, which are vulnerable to disasters, failures, asset forfeiture, and sabotage. The focus of this work is on water distribution networks (WDNs) including different hydraulic elements such as pipes, tanks, valves, and reservoirs to transport drinking water from central treatment plants or sources to consumers. Thereby, efficient identification of system parts in a WDN that are vulnerable to failures is important for efficient management and to provide high reliability. Therefore, often hydraulic simulations are applied, which are computationally intensive and impractical for large networks and multiple pipe failures.In this study, a graph theory-based analysis is used to identify the critical elements (pipes) in a WDN based on "demand edge betweenness centrality (EBCQ)". Therefore, the connectivity of the network based on spatial layout is modelled using a mathematical graph-based approach that represents the topology of the WDN and incorporates hydraulic factors to imitate hydraulic behavior. The mathematical graph consists of #N (vertices) connected by a set of #E (edges) corresponding to nodes and pipes respectively. The ratio of length and diameter is used as edge weight to determine the shortest path, and adds the demands of the nodes to obtain EBCQ values for all edges in that path. In case of pipe failures, the corresponding edge is removed, and the EBCQ of the new graph is calculated and compared with the maximum possible flow to find overloaded and affected edges. Thereby, single and multiple pipe failures are investigated with this method.The method is applied to a benchmark case study and to a real network of an Alpine municipality in Austria. Furthermore, the results of the graph-based method are compared with the results from hydraulic modelling in terms of accuracy and computational time. The first results show only slight differences in the results of the graph-based method compared to those from hydraulic modeling.  Further, the graph-based method is able to identify the same order of critical pipes with low deviation compared to those from the hydraulic model. Additionally, the computational time and data requirements, in the calculation of pipe criticality by graph-based approach is significantly less compared to the hydraulic modelling method. This method is useful in disaster or contamination scenarios where many scenarios or combinations are required.Funding: The project “RESIST” is funded by the Austrian security research programme KIRAS of the Federal Ministry of Finance (BMF).
Diagenesis of Paleogene sandstones and its response to tectonics in Kuqa Foreland Basin, western China
Authors: Yu Guoding , Yuan Jing , Liu Keyu
Published: February 2023

We used the textures and chemical composition of authigenic cements in Paleogene sandstones from DN2 Gas Field of Kuqa Foreland Basin (KFB) and evidence of associated fluids from fluid inclusions and formation water measurements to infer timing of fluid migration and discuss link between fluids and tectonics. Eodiagenesis occurred with the participation of meteoric waters and connate waters. Mesodiagenesis operated in the context of high salinity fluids, which were interpreted to originate from overlying Neogene evaporite. Halite, anhydrite, glauberite, carnallite and thenardite are major minerals for the evaporite. Homogenization temperatures measured in this study and K-Ar dating performed on authigenetic illites by previous study indicate that initial migration of high salinity fluid occurred during the late Miocene (12.4–9.2 Ma). The period is consistent with the crucial phase (13–10 Ma) witnessing the rapid development of southern Tianshan and the stage when calcite and anhydrite veins formed in the studied strata. These results suggest that diagenesis related to high salinity fluids probably occurred as a response to Tianshan’s rapid uplift and related tectonic processes. The flow of high salinity fluids was probably driven by density gradient and channeled and focused by fractures formed contemporaneously.
More is different: On the emergence of collective phenomena in fractured geological media
Authors: Lei Qinghua
Published: February 2023

Fractures such as joints and faults are widely present in crustal rocks. These discontinuity structures often form complex networks and dominate the bulk behaviour of geological media. Thus, understanding how fracture networks affect multiphysical processes and phenomena in subsurface rock formations is highly relevant to many geoenergy and geoengineering applications. However, the large-scale behaviour of fractured rocks consisting of many fractures cannot be derived by simple applications of the knowledge of single fractures, due to the hierarchy of scales, heterogeneities, and physical mechanisms as well as the possible emergence of qualitatively different macroscopic properties. In other words, macroscopic phenomena in fractured media arise from the many-body effects of numerous interacting fractures, such that the emergent properties at the fracture network scale are much richer and often surprising compared to the behaviour of each individual fracture. So, more is different!To study this problem, I have developed a novel physics-based discrete fracture network modelling framework to simulate seismo-thermo-hydro-mechanical-chemical processes in fractured rocks. This modelling approach faithfully honours the discontinuous nature of geological media via explicit representations of fracture populations in rock and numerically computes multiphysics processes by solving the governing equations of fundamental mechanics. No a priori assumption about the representative elementary volume is needed, rendering this approach as an appropriate tool to study hierarchical crustal rocks that may have no characteristic length scale. Using this modelling paradigm, diverse macroscopic phenomena are spontaneously captured as emergent properties physically arising from the collective behaviour of a large population of existing/growing fractures in rock.In this presentation, I will illustrate the richness of collective phenomena in fractured media and elucidate the underlying multiscale, multiphysical mechanisms that drive their emergence. I will also show some application examples of using this fractured media simulation framework to address subsurface engineering problems such as underground excavation, injection-induced seismicity, and nuclear waste disposal. The modelling framework established and research findings obtained have important implications for safe and sustainable development of geoenergy and geoengineering.
Lagged correlation between soil water content and evapotranspiration along recent decades and across different land cover types of Europe
Authors: Rahmati Mehdi , Graf Alexander , Bayat Bagher , Montzka Carsten , Poppe Christian , Vanderborght Jan , Hendricks-Franssen Harrie-Jan , Harry Vereecken Harry Vereecken
Published: February 2023

The link between soil water content (SWC) and evapotranspiration (ET) is of great importance in ecohydrology, agroecosystem management, and land-atmosphere interaction of earth-system analysis. There is still a need to understand the key processes linking SWC and ET in different vegetated ecosystems, especially at larger scales. Therefore, in this work, we used wavelet coherence analysis to explore the long-term relationship between SWC and ET among the predominant land use types (cropland, evergreen needleleaf forest, mixed forest, open shrubland, wooden tundra, grassland, and mixed tundra) in Europe during the last four decades (1980-2020). To this end, first a principal component analysis was performed among the SWC and ET data from GLDAS, GLEAM, and ERA5-land, and the first component was then used for further analyses when the target variable was in demand. Using the first component, then, we averaged SWC and ET data over the pixels covered by each land use type. Then, for each land-use types, we averaged the data daily for each decade to account for a representative decadal year of daily data. Then, wavelet coherence analysis was conducted between those averaged data of SWC and ET for each land-use type. The results showed a negative correlation between ET and SWC for all land use types, with ET lagging behind SWC, with an average phase shift value of 134 days for grassland (the minimum) and 168 days for mixed tundra (the maximum). Converting the phase shift values to a time lag [lag = n/2 - phase shift for the case phase shift < -n/4 where n represents the period (1/frequency) of the signals] shows (Fig. 1) that ET controls SWC with a lag of 15 days in mixed tundra (the minimum) and 48 days in grassland (the maximum). Moreover, we applied Mann-Kendall trend analysis test and found that the lag between SWC and ET decreases in mixed and wooden tundras with a slope value of -2.4 days/year, while it increases in cropland and grassland with a slope value of 1.6 days/year. Although there is a significant downward trend in evergreen needleleaf forests (with a slope value of -0.3 days/year) and an increasing trend in mixed forests and open shrublands (with a slope value of 0.4 days/year), the lower slope values in these land use types indicate that the change is slower compared to grasslands, croplands, and tundras. Figure 1- Temporal evolution of the lag between soil water content and evapotranspiration in the annual cycle in different land use types in Europe 
Aerosol-induced radiation effect and the potential influence of stringent emission control on terrestrial carbon uptake in China
Authors: Li Lingfeng , Qiu Bo , Huang Xin , Guo Weidong , Miao Xin , Chen Jiuyi , Ni Yueyang , Tian Xiaohui
Published: February 2023

Atmospheric aerosols can scatter and absorb the incident solar radiation, and thus impact the land carbon cycle by perturbating the radiation required for photosynthesis. Atmospheric aerosols inhibit the carbon uptake by terrestrial ecosystems through reducing the total amount of incident radiation, while the increased proportion of diffuse irradiance is known to promote photosynthesis. In the past few decades, with the rapid industrialization and urbanization, China has suffered from frequent haze pollution episodes, which have brought up severe environmental problems and ecological impacts. Here, we use a regional climate model, WRF-Chem, along with the offline driven Simplified Simple Biosphere Model (SSiB4) to investigate the impact of aerosol radiation effects on land biosphere carbon uptake capacity. The results show that the current aerosol loading has led to significant decrease in the incident solar radiation in China, which severely suppresses the gross primary production (GPP) and net primary production (NPP). Then, we assessed the influences of stringent emission and pollution control policies on terrestrial ecosystem carbon fluxes. By comparing the simulation results based on China’s ambitious carbon neutrality policies with the reference scenario with negligible emission control, we found that the carbon neutrality scenario with rigorous pollution control increases the incident solar radiation and thereby enhancing the carbon uptake of land biosphere. Under the current state of aerosol loading, the decrease of total amount of incident radiation dominates the suppression of terrestrial carbon uptake, while aerosol diffuse fertilization effect can only partly offset the inhibition of decreased solar radiation on plant photosynthesis. Our findings improve the understanding of the interactions between aerosol pollution and the land carbon cycle, and suggest an appreciable ecological benefit and a potential terrestrial carbon sink enhancement of stringent emission and pollution control actions.