bluuebunny/crossref_metadata_2025 huggingface dataset:
A mantle source for water in Appinite complexes: implications for genesis of granitoid batholiths and crustal growth
Authors: Murphy J. Brendan , Spencer Christopher J. , Archibald Donnelly B. , Collins William J.
Published: March 2024

Appinite plutonic rocks range from ultramafic to felsic in composition, are characterized by idiomorphic hornblende as the dominant mafic mineral in all lithologies, and by spectacularly diverse textures, including planar and linear magmatic fabrics, multiple comb layers, mafic pegmatites and widespread evidence of mingling between mafic and felsic compositions. These features suggest that they are anomalously water-rich mafic magmas.  The ca. 607 Ma Greendale Complex in the Antigonish Highlands of Nova Scotia is typical of appinite complexes which commonly occur as small (~2 km diameter) plutons adjacent to major deep crustal faults along the periphery of voluminous granitoid plutons emplaced in the waning stages of regional arc activity. Isotopic data from hornblendes in the Greendale Complex yield δD values ranging from -61 to -72 and δO18 from 3.7 to 7.0, indicating the water in the appinite magma has a strong mantle component. These data suggest the appinites may represent aliquots of hydrous basaltic magma derived from mafic underplates originally emplaced along the base of the crust during protracted subduction. Transfer of heat and fluids to the base of the crust triggered generation of coeval (615-604 Ma) granitoid magmas by partial melting in the overlying MASH zone. The granitoid magmas were emplaced in the shallow crust when transient stresses activated favourably-oriented structures which became conduits for magma transport. The ascent of late mafic magmas within the Antigonish Highlands was impeded by the rheological barriers created by the structurally overlying granitoid magma bodies. Magmas that form the Greendale Complex evaded those rheological barriers because they preferentially exploited the deep crustal Hollow Fault that bounded the plutonic system.Collectively, these mineralogical, textural and geochemical features suggest a complex magmatic history involving repeated water saturation episodes within the plumbing system as mafic, mantle-derived magmas ascended and differentiated at mid-to-upper crustal levels (ca. 3-5 kbar). More generally, the most mafic components of appinite complexes may provide a window into the composition of the mafic underplate and insights into processes that generate granitoid batholiths and crustal growth in arc systems. 
F-region ionization patches in High Frequency over-the-horizon radar data
Authors: Perry Gareth , Beser Katarzyna , Burrell Angeline
Published: March 2024

Ionization patches are a common feature of the polar-cap, F-region ionosphere. Patches can be detected using a variety of remote sensing instruments including optical imagers and incoherent scatter radars. Due to their pronounced plasma density gradients, patches are believed to be a strong source of decameter-scale field-aligned-irregularities which are responsible for ionospheric backscatter observed by High Frequency (HF; 3 – 30 MHz) over-the-horizon (OTH) radar systems. Indeed, Super Dual Auroral Radar Network (SuperDARN) systems at high latitudes have been used for investigating polar-cap patches for decades. Current techniques for identifying patches in SuperDARN ionospheric backscatter data are rudimentary and labor intensive as they require human intervention—an automated detection algorithm does not yet exist. This presentation will detail progress on the development of an automated algorithm for detecting patches in SuperDARN ionospheric backscatter data. The end-goal of the development effort is to transition the algorithm into a near real-time patch detection capability for SuperDARN and other OTHR systems. Patches are an important signature of magnetosphere-ionosphere-thermosphere (M-I-T) coupling in the polar regions; they are also an agent of space weather as they are a source of HF scintillation there. An automated algorithm for detecting patches will allow for their potentially hazardous influence on HF radio wave propagation conditions to be identified and mitigated.
Linking connectivity to spatiotemporal variability in sediment dynamics and yield in glacierized, mountainous watersheds
Authors: Turley Mike , Hassan Marwan , Zimmermann Andre , Schaarschmidt Maria , Lian Olav , Friele Pierre
Published: March 2024

An understanding of catchment-scale processes and sediment dynamics is crucial for the informed and sustainable development of mountain communities. Given the steep topography, glacier retreat, and intensifying weather patterns due to climate change, many mountain towns face heightened vulnerability to geohazards. Studies show that as glaciers retreat, paraglacial processes typically lead to elevated sediment yields, exacerbating existing hazards. However, postglacial landscapes are dynamic, complex, and heterogeneous systems shaped by a variety of processes, and no two systems are the same. The efficiency in which glacial sediments are reworked and transported to and through river systems (connectivity) varies over time and space. In this study, we investigate the link between landscape history, sediment (dis)connectivity, and postglacial sediment dynamics in a glacierized, mountainous catchment in Southern British Columbia. We begin by mapping the geomorphology, identifying sediment sources, storage landforms and transfer processes. Subsequently we employ morphometric analysis and landform mapping paired with age estimates, to quantify sediment yield. These results are compared to historical channel changes and estimates of structural connectivity to better understand the variation in postglacial sediment dynamics. By integrating diverse datasets and methodologies, we are able to estimate the variability in sediment yield and changing relative contributions of sediment sources at a range of spatial and temporal scales. Preliminary results of this work shed light on and underscore the need for additional studies that investigate long-term (e.g., postglacial) changes in sediment connectivity. Such research can inform decision-making in landscapes that are rapidly changing and experiencing deglaciation.
Scientific Support for the Treaty on the Prohibition of Nuclear Weapons
Authors: Seibert Petra , Hughes Ivana , Stott Noel , Suarez Gerardo , Kabir Zoardar A. K. M. Raushan
Published: March 2024

The Treaty on the Prohibition of Nuclear Weapons (TPNW) was negotiated and adopted in 2017, entered into force 2021, and currently has been signed by 93 states, of which 69 have ratified. The Treaty was born out of concern about the devastating impact of nuclear war and growing frustration among non-nuclear-weapon states about the lack of progress with serious nuclear disarmament [1, 2]. It is built on a solid scientific base, laid during a series of conferences on the humanitarian impact of nuclear weapons in 2013 and 2014, held in Norway, Mexico, and Austria [3]. The Treaty not only bans a wide range of activities related to nuclear weapons, but it also includes provisions for victim assistance and environmental remediation in places affected by nuclear weapons use and testing [4].Recognising the importance of science for the implementation of the Treaty, the 1st Meeting of States Parties in summer 2022 decided to create a Scientific Advisory Group (SAG) of 15 members, nominated by States parties, but acting independently. It mandated the SAG to produce a ”Report on the status and developments regarding nuclear weapons, nuclear weapon risks, the humanitarian consequences of nuclear weapons, nuclear disarmament and related issues”, which was delivered in autumn 2023. Furthermore, the SAG was tasked to ”identify and engage scientific and technical institutions in States parties and more broadly to establish a network of experts to support the goals of the Treaty”.The presentation will highlight some key points of our first report [7], and outline our current plans for building the Scientific Network. We also plan to offer a Townhall Meeting for those interested in network membership.References[1] Alexander Kmentt, The Treaty Prohibiting Nuclear Weapons, How it was Achieved and Why it Matters. Routledge 2021/2021. ISBN 9780367531959. [2] Ray Acheson, Banning the Bomb, Smashing the Patriarchy. Rowman & Littlefield, 2021. ISBN 9781786614896.[3] Vienna Conference on the Humanitarian Impact of Nuclear Weapons, 2014, [4] United Nations Office for Disarmament Affairs, Treaty on the Prohibition of Nuclear Weapons, [5] ICAN, Intersessional Progress on the TPNW – Scientific Advisory Group, [6] Institutionalizing scientific and technical advice for the effective implementation of the Treatyon the Prohibition of Nuclear Weapons, TPNW /MSP/2022/WP.6, [7] Report of the Scientific Advisory Group on the status and developments regarding nuclear weapons, nuclear weapon risks, the humanitarian consequences of nuclear weapons nuclear disarmament and related issues, 2023,
The power-law distribution of the rock pore structure: inversion and analysis of laboratory velocity-pressure data
Authors: Wang He-Ming , Tang Xiao-Ming , Doan Mai-Linh
Published: March 2024

Linking the pore structure distributions and velocity-pressure relationship is important for understanding geological processes and in situ stress conditions. During the pressure loading, the pressure-velocity relationship is controlled by variation of pore-aspect-ratio spectrum distribution (pore-aspect-ratio vs. porosity) with pressure: on the one hand, the “flat crack” (aspect ratio) will be squeezed and closed, causing the large velocity variation in the low-pressure regimes; on the other hand, the shape and volume of the “round pore” (aspect ratio) are less sensitive to pressure, controlling the smaller velocity change at high pressures. The above pore-structure variation process and its effect on the velocity-pressure relationship allow us to invert and analyze the distribution characteristics from the laboratory velocity-pressure data.  The power-law distribution has been universally applied to characterize the length and aperture distribution in natural fractures; however, it is still not well understood whether the pore-aspect-ratio spectrum distribution also follows the power law and how this power-law distribution relates to other power-law distributions of fractures. In this study, we examine the universality of the power-law relationship for the pore aspect ratio spectrum distribution and show that this distribution is the natural outcome of the power-law behavior of the length and aperture distribution in the rock fracture network.We first collected laboratory ultrasonic velocity-pressure data for 52 rock samples with various porosities and lithologies. We then used a power law assumption to link the pore aspect ratio and porosity. The power-law exponents (hereafter referred to as the E factor) of the power-law distributions were successfully obtained by inverting the compiled velocity-pressure datasets. The inversion results showed a universal relationship between the E factor and porosity. We also demonstrated that the power-law distribution of the pore-aspect-ratio spectrum and the universal E factor-porosity trend can be explained using the length and aperture distribution characteristics of the microcrack system of rocks. This universal E factor-porosity trend provides a link between porosity and sensitivity of seismic velocities to pressure. Hence, our work not only emphasizes the relevance of natural fracture fractal distributions for a broad range of lithologies but also provides the parameterized method for relating the velocity-pressure relationship of any rock to porosity variation.
Untangling the Multi-model Spread in 21st Century AMOC Projections
Authors: Ashton-Key Harry , Mecking Jennifer , Drijfhout Sybren
Published: March 2024

The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the global climate by transporting heat northward. According to the latest IPCC report (AR6) the strength of the AMOC is very likely to weaken by 2100 (Fox-Kemperer et al. 2021). A weaker AMOC would significantly impact local and global climate. However, there is large model spread in the magnitude of the projected reduction in AMOC strength (Weijer et al. 2020) so it is unclear to what extent the AMOC will weaken by the end of the 21st century.This study investigates the spread in AMOC response among CMIP6 models. As an initial step we investigated the model correlations of AMOC weakening across different ScenarioMIP experiments. Preliminary results show that the decline for similarly forced scenarios, such as ssp370 and ssp585, have stronger correlations than for scenarios with significantly different forcing, such as ssp126 and ssp585.Further analyses into the relationship between the projected weakening and model biases in ocean temperature,  salinity and meridional density gradients are performed. In addition, we investigate how the weakening correlates with possible drivers. A better understanding of how model biases influence AMOC changes will allow for more accurate projections of future AMOC changes and their impacts, as well as improved understanding of what the driving processes of the weakening are in various models.
Comparing the Dust Devil Vortex Populations on Mars and Earth
Authors: Lorenz Ralph
Published: March 2024

 Convective vortices, and their particle-laden counterparts dust devils, are an important feature of the meteorology of both Mars and terrestrial desert areas. In addition to being interesting phenomena in their own right, they can cause occasional damage and even death.  The last 12 years has seen the generation of statistically-robust catalogs of vortex encounters from long-lived (>1000 Sol) landers and rovers equipped with meteorological instrumentation, namely MSL, InSight and Mars 2020.  Although previous landers (Phoenix and Pathfinder, lasting ~100 Sols) yielded catalogs that were enough to indicate useful analytic function descriptions of vortex population functions (e.g. power laws or exponentials of number versus measured pressure drop), the new generation of missions provide much more robust statistics, and also have had more extensive instrumentation, permitting the documentation of wind speed, dust loading and even seismic characteristics of vortex encounters.In the 2000s, the Mars statistics were in fact rather better than those available for the Earth, but the advent of inexpensive and low-power data logging systems with flash memory permitted the long-duration (months) acquisition of high-cadence (>1/second) pressure and other data required to detect small vortices in unattended field measurement campaigns. Inexpensive timelapse cameras have also permitted optical surveys of dust devils that are comparable with those from Mars landed and orbital missions.In many respects the populations of vortex events are surprisingly similar on the two worlds, when expressed as a normalized peak pressure drop (pressure drop divided by ambient pressure : this quantity is proportional to the peak wind speed at the wall of the vortex).  The cumulative rate of encounters typically varies as a power law with an exponent of about -2, and Martian rates are a factor of several higher than those on Earth.  Although the convective heating rates of the respective surfaces are somewhat different, a key difference is that the Martian Planetary Boundary Layer, which sets the upper limit on vortex size, is much deeper, and Martian dust devils are typically larger than Earth’s as a result.  I will review these population functions and their implications for meteorology, dust lifting and safety.
Changes in Flood Risk to Cultural Assets Under Climate Change - A Case Study of  Kinmen
Authors: Chen Shou-Chi , Ma Kuo-Chen , Chuang Mo-Hsiung , Lin Wen-Yen
Published: March 2024

Amidst global climate change, extreme weather events are becoming increasingly common. The international community has established 'preventive conservation' of cultural assets as a core strategy. Nations are actively devising measures to counter the potential impacts of climate change on cultural assets and developing related adaptive strategies. Particularly noteworthy is the often-overlooked potential risk of natural disasters to cultural assets, which poses a severe threat to these irreplaceable assets.This study focuses on the Kinmen area of Taiwan and utilizes data provided by the Taiwan Climate Change Projection and Adaptation Knowledge Platform (TCCIP). Employing flood risk maps as the primary analytical tool, it delves into the changing risks faced by cultural assets under climate change and explores how to implement preventive conservation strategies.The research reveals that during the baseline period (1980-2015), Kinmen had 287 cultural assets, with 4 facing the risk of flooding. According to the extreme weather scenario AR5 (RCP 8.5) provided by TCCIP, it is predicted that various regions will experience more intense rainfall conditions in the mid-21st century (2041-2065), increasing the risk of flooding and leading to more cultural assets (18 in total) being threatened. Therefore, through meteorological data projection and disaster risk assessment, this study advocates for early preventive conservation measures for high-risk cultural assets, aiming to mitigate the potential impact of climate change on these valuable assets.
A New Dike Propagation Model Linking Seismicity and Rock Damage Mechanics
Authors: Zhan Yan , Huang Yiwen
Published: March 2024

Dikes feed volcanic eruptions, causing devastating hazards and global impacts. Monitoring magma ascent through dike propagation can significantly enhance hazard assessment and mitigation. However, direct observation of dike propagation remains elusive. Among the available data, dike-induced earthquakes offer the best tracing of subsurface dike movement. These earthquakes may facilitate dike propagation by damaging the rock or slowing down the dike by releasing accumulated stresses. Yet, the relationship between these earthquakes and rock damage remains unclear. To clarify this relationship, we have developed a new dike propagation model that couples damage mechanics with porous flow to explore the local stress field's influence on fluid mobility within the dike. Our model's results show that the energy released during the rock-damaging process aligns with the seismicity induced by the dike. Furthermore, the model-calculated local stresses near the dike can explain the observed fault plane solutions associated with dike propagation. The new model also reveals the controls on magma ascent velocity, intrusion geometry, and surface deformation, with implications for other volcanic systems such as Bardarbunga, La Palma, and Piton de la Fournaise volcanoes.
Ionospheric responses modulated by quasi-periodic EMIC waves associated with ULF waves
Authors: Ma Longxing , Yu Yiqun , Tong Xin , Tang Linhui , Liu Wenlong , Cao Jinbin , Wu Jun , Wu Jian
Published: March 2024

Energetic protons can be efficiently scattered by electromagnetic ion cyclotron (EMIC) waves into the upper atmosphere. This process represents a crucial mechanism for the exchange of energy and particles between the magnetosphere and ionosphere. In this study, quasi-periodic EMIC waves induced by Pc4 ULF waves were observed by the Van Allen Probes (RBSP) B satellite during a magnetic storm event on September 8, 2017. The associated pitch angle diffusion coefficient 𝐷𝛼𝛼 reveals that the quasi-periodic EMIC waves predominantly affect 30-100 keV protons. Concurrently, RBSP-B measurements indicated a remarkable quasi-periodic enhancement in the proton flux near the loss cone, with a frequency consistent with EMIC wave packets. Observations from the NOAA-19 satellite exhibited a substantial increase in 30-100 keV proton precipitating fluxes. Periodic proton precipitation resulted in clearly quasi-periodic enhancements of electron density in the ionospheric E-region detected by the European Incoherent Scatter (EISCAT) radar.
Unraveling the Origins and Dispersal of Austronesian Culture by the last deglacial sea-level rises and paleoenvironmental changes: Insights from the Taiwan Strait
Authors: Zhang Ke , Zhang Suixin
Published: March 2024

The Austronesian population, which consists of approximately 0.4 billion people, is widely spread across the Pacific and Indian Ocean islands. Extensive research over several decades has led to an academic consensus that the Austronesian population originated from Taiwan and the southeastern coast of mainland China. However, the exact manner in which the Austronesian ancestors arrived in Taiwan and subsequently dispersed to other oceanic regions remains a mystery. By analyzing the last deglacial sea-level rise, neotectonic activities, and resulting ancient environmental changes, as well as comparing the characteristics of middle Neolithic remains (dating back approximately 7.4-4ka) between the Taiwan Strait, we have proposed the existence of a “proto-Austronesian culture” in the early Holocene (around 11.7ka~7.4ka). This culture was centered around the nearshore area of the Taiwan Strait and Taiwan Shoal region. As sea levels gradually rose, the Austronesian ancestors’ habitat became increasingly submerged, compelling them to retreat to the inshore highlands on both sides of the Taiwan Strait. The Austronesian relics discovered on both sides of the Taiwan Strait, such as Dabenken, Keqiutou, and Fuguodun, among others, are actually branches of the Austronesian ancestors, inheriting their marine ecological characteristics. The scarcity of Neolithic artifacts older than 7.4ka on both sides of the Taiwan Strait can be attributed to a “survivor bias” phenomenon. It is plausible that numerous early Holocene relics of the “proto-Austronesian culture” remain submerged in the nearshore area of the Taiwan Strait and Taiwan Shoal, eagerly awaiting discovery through submarine archaeological exploration.
Multidisciplinary Implications from the post-2015 Chandler Wobble Anomaly
Authors: Furuya Masato , Yamaguchi Ryuji
Published: March 2024

Given the disappearance of the 6-year beat in recent polar motion data, we have pointed out that the Chandler Wobble (CW) has not been excited since 2015 and further examined if the presently available Earth-system-modeling data can explain the anomaly  (Yamaguchi and Furuya 2024, doi:10.1186/s40623-023-01944-y).  Here we discuss its implications from meteorological and geodynamical points of view.We confirmed that two independent atmospheric angular momentum (AAM) data from ERA5 and JRA-55 were almost in perfect match with each other in terms of their persistently smaller contributions to the CW excitations in recent years. We thus examined the temporal changes in the regional contributions to the global AAM, using JRA-55 reanalysis data. While the mass term exhibited no significant changes in any latitude zones throughout the analysis period, the motion term in some latitude zones exhibited larger amplitudes since 2015 than before. We speculate its possible connections to the recent anomalies of the quasi-biennial-oscillation in 2015/2016 and 2019/2020.Another important conclusion in Yamaguchi and Furuya (2024) is that the quality factor (Q) of the CW is not as high as 100, which has been preferred in previous studies, whereas there have been a couple of times differences even in the recent Q estimates; e.g., from 49 by Furuya and Chao (1996), 97 by Seitz et al (2012), 127 by Nastula and Gross (2015). While Smith and Dahlen (1981) preferred Q~100 and quantitatively interpreted the period and Q in terms of a frequency-dependent mantle anelasticity, the lower Q than previously thought will suggest a need to revise the theory and have an implication for the lower-mantle rheology.  
Open Air Quality Community Data in Pakistan
Authors: Omar Abid , Marciel F. Rosales Colleen
Published: March 2024

Cities in Pakistan consistently report extreme levels of air pollution, with our low-cost sensor data ranking Lahore as the most polluted major city in the world with annual average PM2.5 levels at 105 µg/m3, and hourly peak eposides reaching 900 µg/m3. At the same time, these cities remain a ‘data gap’ in terms of availability of air quality data with sporadic monitoring by government or by other institutions. Moreover, there is little scientific research interest for Pakistani cities, especially in comparison with other regional LMIC cities that have relatively lower air pollution levels and affected populations.This paper is the first comprehensive survey of available data for Pakistan, by publishing seven years of low-cost sensor data collected by a low-cost sensor community network for the 4 largest cities in Pakistan, namely Karachi, Lahore, Islamabad, and Peshawar. Statistical comparisons with available reference-standard data and remote sensing data is also done.  Challenges in data collection are also covered when working in LMIC city areas affected by access issues, intermittent electricity supply and data outages, as well as the learnings from seven years of community work, and use of sensors for community awareness and advocacy in Pakistan. The impact from this community monitoring network has been instrumental in kick-starting awareness in one of the most air-polluted regions of the world.
Water quality evaluation and trend analysis during typical operation of large-scale long-distance open water diversion project
Authors: Jia Benyou , Fan Ziwu , Su Kun , Liao Yipeng , Yang Fan , Wang Wei , Li Dandan , Xie Chen
Published: March 2024

Water resources in northern region of China are severely scarce all year round, and water supply in the region is not guaranteed, and regional ecological environment is deteriorating day by day. In order to alleviate this phenomenon, national and local governments have implemented many cross-basin and cross-regional water resource allocation projects, the most famous of which is the China South-to-North Water Diversion Projects. This has also raised concerns from Ecological Environment Department about of water quality safety when implementing water diversion, especially under condition of connected river systems. This article takes Jiangsu section of the East Line of South-to-North Water Diversion Project as a research case. Based on water quality monitoring stations set up and monitoring data along the water conveyance rivers during water diversion operation from 2019 to 2020, single index method and comprehensive water quality identification index method are used to evaluate the water quality status of each water conveyance rivers, so as to two water source areas of Yangtze River and Hongze Lake. Trends of different water quality indicators along the line are given, and reasons for water quality changes are analyzed. Results show that during typical annual water diversion operation period, overall water quality of each water conveyance river meets the Surface Water Class III standard, rivers such as Sanyang River, Tonghe River, Jinbao Channel, et al., which are sourced from Yangtze River, are Class III and Class II. Xuhong River, which is sourced from Hongze Lake, is slightly worse than other rivers, and there is a Class IV situation in December 2019 and May 2020, because CODMn is not meeting Class III standard. Water quality evaluation of Yangtze River is classified as Class II all year, while Hongze Lake is classified as Class IV in some months, with main exceeding indicator being TP. Overall water quality in the line shows a trend of gradually deteriorating from south to north, which is closely related to the actual water quality background of Yangtze River and Hongze Lake, as well as the actual pollution load entering water conveyance rivers along the line. One of the most important reasons is that water conveyance river also plays as a drainage channel, which needs to undertake water withdrawal and drainage of regional agricultural production activities.
Extreme value methods in dynamical systems of different complexity
Authors: del Amo Ignacio , Datseris George , Holland Mark
Published: March 2024

Extreme value theory provides a universal limit for the extremes of continuous independent and identically distributed random variables and has proven to be robust to generalisation to wider classes of random variables, including stationary processes, some nonstationary processes and even trajectories on deterministic chaotic systems. This universality, together with the fact that these methods require data from only one realization of the system, has been exploited in applications to study many series of climate data.Fitting a probability distribution to the extreme events of a data series generated by a chaotic dynamical system gives us not only probabilistic predictions of the intensity and return time of the events themselves, but also geometrical information about the local structure of the attractor and the predictability and persistence of the extreme events.However, these methods are sensitive to the mathematical properties of the dynamical system that generates the data, and are seldomly even mentioned when they are applied to real climate data. One further caveat of these methods is that they are hard to falsify, i.e. we cannot verify easily if an answer is wrong. For these reasons, we explore how these methods respond to different systems with different complexity and different mathematical properties, trying to understand which of the results on the literature could meaningful and which could be numerical artifacts.
Compounding risks from droughts and hot extremes across different regions due to energy linkages 
Authors: Hao Zengchao
Published: March 2024

Droughts can affect a variety of sectors, such as water resources, agricultural yield, and energy security. Moreover, their impacts can cascade or propagate to other regions due to the physical or socioeconomic linkages. Though drought impacts on energy (e.g., hydropower generation) have been well explored, their effects, in tandem with other extremes, such as heatwaves (or compound droughts and hot extremes), across different regions have been less explored. In this study, we demonstrated the compounding risk of droughts in Southwest China and hot extremes in East China (with hydropower transmission from Southwest China), which collectively presents challenges to energy security in East China. We then explore the changes in the characteristics of such spatial compounding of droughts and hot extremes across different regions in historical periods. Finally, future risks of such extremes are also explored based on simulations from Coupled Model Intercomparison Project Phase 6 (CMIP6). This study can be useful for understanding compounding risks with impacts transmitted to remote locations through physical or socio-economical pathways.
Standards: a key tool for DDE
Authors: Robida Francois , Minghua Zhang , Thorleifson Harvey , Rattenbury Mark
Published: March 2024

DDE's ambition is to make better use of data from the earth sciences to produce new knowledge using new digital tools such as AI. The earth sciences have always relied on observations to produce knowledge. Scientists have always had a duty to ensure the quality of their data and to enable it to be reused by other researchers, by describing it as precisely as possible.In the DDE approach, which makes use of vast quantities of digital data from a variety of sources, it is particularly important to be able to ensure the quality and relevance of the data used, in order to have confidence in the results produced by this approach. These data may have been produced by the scientific community on different continents, at different times, often for specific purposes.When data is made available to researchers on platforms, it must comply with the FAIR (Findable - Accessible - Reusable - Interoperable) principles. For these principles to be implemented, the international community needs to agree on common terminologies and ontologies produced by the scientists themselves. This approach will provide machines with the reference systems needed for the reasoning used in AI.As part of DDE, a Task Group on Standards (DDE/STG) has been set up to adopt common standards and a common approach to producing and updating these standards. This task group draws on the expertise of the Commission for the Management and Application of Geoscience Information (IUGS/CGI) and the Committee on Data of the International Science Council (CODATA). This presentation will provide an update on this work.
The central role of geoscience data standards in generating new knowledge
Authors: Robida Francois
Published: March 2024

The earth sciences are first and foremost observational sciences, based on data collected on the planet over generations. It is from this data that interpretations, concepts and models are produced. The description of data by those who produced it and its conservation has always been a concern for scientists, to enable it to be reused and reproduced. This has been achieved by adopting common rules and standards, for example for indicating the geographical coordinates of an observation or the units of measurement used.Today's scientific challenges, first and foremost the climate challenge, require the mobilisation of different scientific disciplines, often with different languages and practices.The establishment of data infrastructures on an international scale means that researchers can use computer protocols to access considerable sources of data from their own and other disciplines. Digital tools such as AI make it possible to make machines 'reason' about data to produce new knowledge.All these factors make it critical for both humans and machines to be able to 'understand' the data used. This understanding necessarily requires the adoption of common reference systems on an international scale and across all disciplines. These standards are based on a common 'vision' produced by the scientific community (and updated as knowledge evolves), resulting in vocabularies and ontologies shared by the community.This presentation will look at the ecosystem for producing and maintaining standards for the geosciences and some of the issues involved in the relationship between scientists and the production and use of standards.
Exploration of a Unified Process Interpretation for Seasonal and Annual Water Balances in Snowy Catchments
Authors: Wang Zeqiang , Berghuijs Wouter R. , Howden Nicholas , Woods Ross
Published: March 2024

Snow accumulation and melt dynamics provide influences on streamflow seasonality and mean annual flow which are not present in snow-free areas. Most studies of snow hydrology focus on one timescale, which limits and fragments the understanding of catchment behaviour. Establishing which process controls on hydrological responses act across multiple time scales is still challenging due to the wide range of climates and landscape conditions that may affect the catchments’ hydrological functioning. Here, we build upon prior research that showed how climate and soil drainage effects both shape seasonal and mean annual water balances in humid, snow-free catchments. We establish process controls on seasonal and mean-annual hydrological responses to unify the process interpretation across time scales for diverse snow-influenced catchments. We use observed streamflow, climate and catchment attributes data in snow-affected catchments from the CAMELS_US dataset to assess the impacts of climate and landscape on catchment responses. We use a conceptual model to unify the mechanistic explanation for seasonal and mean annual water balances. We hypothesize that the interaction between climate aridity, the fraction of precipitation falling as snow, and landscape properties (soil, geology and topography) in snow-affected catchments shapes both streamflow seasonality and mean annual flow.
Towards an Integrated Groundwater Management and Flood Control in Arid Qatar: Insights from GIS-Driven Multi-Criteria Decision Analysis
Authors: Aloui Sarra , Zghibi Adel , Mazzoni Annamaria , Elomri Adel , Al-Ansari Tareq
Published: March 2024

Groundwater resources in arid regions play a crucial role in meeting water demands; however, they are facing rapid depletion due to unsustainable exploitation practices, exacerbated by climate change. As climate extremes intensify, there is a growing emphasis on harnessing flood and storm flows to replenish overdrawn aquifers. Floods can present a unique opportunity for restoring groundwater levels and mitigating saltwater intrusion into aquifers. The use of effectively managed floodwater for aquifer recharge offers a dual advantage by maximizing the potential of floods as a valuable water resource, while minimizing their negative impacts.This work proposes an integrated approach to evaluate the geospatial suitability of groundwater recharge using floodwater across Qatar, a peninsula located in the eastern part of the Arabian Peninsula. We applied a Quantum GIS-based Multi-Criteria Decision Analysis (MCDA) approach, namely the Analytic Hierarchy Process (AHP), to delineate flood susceptible zones and groundwater recharge zones in Qatar, considering several influential topographical, hydrological, environmental, and anthropological criteria. The maps of flood susceptibility and potential groundwater recharge zones were validated using recent flooding events and existing recharge wells data, respectively. Sensitivity analysis was conducted on both variables to further assess their accuracy. The overlay analysis of the two validated maps, encompassing 98% of the entire country's surface, suggests that approximately 64% of the Qatar peninsula presents medium to excellent suitability for aquifer recharge using floodwater. The areas best suited for floodwater-based recharge intervention are located in the northern and coastal regions of the peninsula, while the urban areas and southwestern area are less suitable.The findings of this study provide decision-makers with spatially explicit information for targeted aquifer recharge projects, potentially mitigating groundwater depletion, enhancing water security, and improving flood risk management in Qatar. In addition, we offer insights into further investigation areas, encompassing technical, economic, and regulatory considerations, to enhance the applicability and effectiveness of the proposed groundwater recharge strategies. The approach employed can be effectively applied in similar flood-prone arid regions and is adaptable to diverse contexts.
Retrieving leaf area index in wheat fields using unmanned aerial vehicle (UAV)-based LiDAR and hyperspectral imagery
Authors: Mulero Gabriel , Bonfil - Jacques David , Helman David
Published: March 2024

Leaf Area Index (LAI) is a dimensionless measure representing the total leaf area per unit ground area. As such, LAI is a key parameter in crop models, as it directly influences the photosynthetic activity of crops, affecting their growth, development, and yield predictions. It also reflects the canopy structure, which plays an essential role in how the plant responds to environmental stresses. In this study, we used UAV-based light detection and ranging (LiDAR) data and hyperspectral imagery (HSI) as two modalities to predict LAI in a total of 60 plots within 10 wheat fields of various cultivars in the dryland areas of Israel. Field LAI was assessed via two methods – destructive (Li3100C, Licor, Nebraska, USA) and optical (Li2200C, Licor, Nebraska, USA). The LAI in the wheat fields ranged from 0.25 m2 m–2 to 7.7 m2 m–2 (average LAI over the dataset was 1.5 m2 m–2). To predict LAI, we used LiDAR-derived metrics such as height-related metrics (height percentiles and bi-centiles, canopy relief ratio (CRR), max, average, and mode height), and 3-D variables (3-D profile index (3DPI), 3-D voxel index (3DVI), and convex hull volumes), as well as spectral vegetation indices, in five machine learning (ML) algorithms – simple linear regression (SLR), partial least squares regression (PLSR), support vector machine (SVM), Random Forest (RF), and Extreme Gradient Boosting (XGBoost). Single metric SLR resulted in R2 ranging from 0.32 to 0.55. More complex algorithms showed that the LiDAR-derived metrics were useful for estimating LAI at the plot level with a higher R2 > 0.81 and an RMSE of less than 0.16 m2 m–2 (c. 10%) for the ML algorithms. The 3-D variables were shown to be the most important and robust variables in the ML models for predicting LAI at the plot level, with some height-related variables showing great potential as well. This study is a unique first-step effort to evaluate UAV-LiDAR sensors in collecting high-quality, non-destructive, repeatable measurements of LAI. Such remote sensing information could be highly useful to calibrate and evaluate crop models while resolving the upscaling limitation from leaf to canopy.
Unraveling Natural Gas Migration Rate and Extent from Leaking Underground Pipelines under Varying Environmental Conditions
Authors: Smits Kathleen , Jayarathne Navodi , Zimmerle Daniel , Riddick Stuart , Kolodziej Richard
Published: March 2024

Natural gas (NG) leakage from belowground pipelines is currently poorly understood, even though it is an area of safety, environmental, and economic concern. To date, there are limited studies on the transient behavior of NG, defined as the speed and maximum extent that gas travels belowground, and how this behavior changes with soil, environmental and leak characteristics. What is least identified is the interrelation between each controlling parameter, how to properly parameterize and characterize as well as the proper field application, specifically operator and first responder protocols. To address this gap, this work identifies key parameters influencing the transient behavior of leaked NG in the subsurface and opportunities to link this understanding to operator practice.  Though a three-year long series of over 150 controlled release experiments conducted at Colorado State University’s Methane Emission Technology Evaluation Center (METEC) and parallel numerical modeling we’ve investigated subsurface methane migration rates and extents and subsequent emission to the atmosphere. Experimental results were used to understand overall transient behavior both during and after terminating the leak. Numerical simulations were then used to extend experimental results to other conditions (e.g. additional soil types, surface conditions, and belowground infrastructure). Results demonstrate the impact of temporary rain and snow surface conditions on the extent and duration of leak transport, resulting in levels that pose heightened environmental and safety risks.  Furthermore, after leak termination, our findings demonstrate the isolated changes in the belowground migration time and the extent of leaked gas, driven by changes in surface and atmospheric conditions, a key point not consistently included in risk assessments or environmental emission rate calculations. While efforts to study a wider range of environmental conditions is underway, the findings of this study provide crucial insight to on identifying and prioritizing emissions from the perspective of both safety and the environment. 
Integration of Automated River Fow Discharge and Sediment Observation Systems and Applications
Authors: Yang Shenghsueh , Jhong Renkai , Wu Iyu , Ma Jialin , Yeh Kehchia , Weng Chihcheng
Published: March 2024

The widespread application of IoT observation technology has further improved and timely applied river monitoring technology, especially during floods, providing instant judgment and disaster prevention applications. However, real-time sediment observations often lack data due to considerations such as river water sampling and personnel safety during river floods. Therefore, it is necessary to integrate various observation instruments for observation. The river flow discharge part includes radar water level gauges, river surface current meters and CCTV (Closed-circuit television) images for recording, and combined with cross-section measurement data, real-time river flow discharge estimation can be achieved. The sediment observation part includes the observation of river suspended load and river bed load. The river suspended load is installed on the bridge foundation to directly measure the sediment concentration through optical concentration monitoring. The river bed load flux is monitored through microseismic wave instruments to obtain the bottom of the river bed load movement. The bed material load flux measure migration produces a large number of microseismic and collision frequencies, and the river bed load flux is estimated through frequency intensity spectrum analysis. Finally, based on the observation time of each monitoring instrument and cloud database records and back-end analysis and calculation, the hydrological observation web page integration and real-time water level, flow and sediment content integrated display and value-added applications such as embankment safety and bridge scour safety settings were carried out.
Multi-centennial variability of the Atlantic Meridional Overturning Circulation: underlying mechanisms and its response to elevated CO2 levels 
Authors: Cao Ning , Zhang Qiong , Power Katherine
Published: March 2024

Multi-centennial climate variability, evident in paleoclimate proxy records and observed in both forced transient and unforced control simulations with numerous fully coupled climate models, presents a significant yet elusive phenomenon in climate dynamics. This study, utilizing a coupled climate model EC-Earth3-LR, identifies and analyzes a prominent multi-centennial climate variability with a distinct 200-year cycle in a pre-industrial (PI, with atmospheric CO2 concentration of 280 ppmv) control simulation. This oscillation originates predominately from the North Atlantic and displays a strong association with the Atlantic Meridional Overturning Circulation (AMOC). We pinpoint the crucial interplay between salinity advection feedback and vertical mixing in the subpolar North Atlantic as key roles in providing the continuous internal energy source to maintain this multi-centennial oscillation. The perturbation flow of mean subtropical-subpolar salinity gradients serves as positive feedback that sustain the AMOC anomaly, while the mean advection of salinity anomalies and the vertical mixing acts as negative feedback, constraining the amplitude of AMOC anomaly. In warmer climate conditions, with atmospheric CO2 concentrations elevated to 400 ppmv and 560 ppmv, we observe an expected stabilization of the water column in the North Atlantic deep-water formation regions, potentially leading to a reduction in the AMOC. These conditions are simulated to assess the evolution of unforced internal multi-centennial variability under higher CO2 levels. Results show that while multi-centennial climate variability persists in these warmer climate states, oscillation amplitudes are diminished. Despite the reduced intensity, the most pronounced effects remains in the North Atlantic and the Arctic, hypothesized to be driven by AMOC fluctuations. In contrast to the PI simulation, where the Arctic and subtropical fluxes exhibit aligned power spectra peaks, the warmer climate scenarios reveal longer timescales and reduced amplitudes in multi-centennial climate variability, suggesting a climate state dependence in the subtropical mechanism. Notably, while the subtropical salinity feedback is coupled with the Arctic mechanism in the PI state, it evolves into a weaker, slower, and self-sustaining mechanism in warmer climates.