bluuebunny/crossref_metadata_2025 huggingface dataset:
Isotopic signatures from the weathering of ophiolitic massifs and volcanic deposits in the Zambales region, Philippines.
Authors: Cheung Chris Tsz Long , McKenzie Ryan , Guotana Juan Miguel , Beaty Brian , Qin Yonghui , DeFrancesco Giancarlo , Pedrezuela Bianca Maria Laureanna , Asael Dan , Planavsky Noah , Faustino-Eslava Decibel V.
Published: March 2024

Lithium isotopes (d7Li) are a useful proxy to track silicate weathering, the fundamental process in which carbon is removed from Earth’s surface. Here we present d7Li and elemental data from 14 riverine localities in the Zambales region, Philippines. The warm, humid climate coupled with monolithic rivers draining ophiolitic massifs and volcanic deposits (from the major 1991 Pinatubo eruption) allows for the comparison of silicate weathering and riverine geochemistry across different lithologies. The most striking part of our dataset is that all rivers draining ophiolitic terranes have heavier d7Lidiss values (range from 22.8 to 37.1‰) than those draining Pinatubo volcanic deposits (range from 8.9 to 18.4‰). As all rivers feature similar topographic relief and hydrological conditions, this suggests a strong lithological influence on d7Lidiss values despite both bedrock lithologies being highly weatherable. We postulate that the mafic and ultramafic composition of the ophiolite terrain significantly enhances incongruent weathering and clay mineral formation, increasing Li fractionation, and leading to the heavier d7Lidiss values. Conversely, the lighter d7Lidiss values for the Pinatubo rivers could be explained by the more felsic composition and unconsolidated nature of the volcanic deposits leading to increased congruent weathering and low clay formation, and thus low Li fractionation. Notable differences in major element concentrations are also observed. The Mg2+ is the dominant cation in ophiolitic-draining rivers reflecting the weathering of Mg-rich mafic and ultramafic minerals. Meanwhile, Na+ and Ca2+ dominate in rivers flowing off the Pinatubo volcanic deposits. The ophiolitic-draining rivers also have total major cation concentrations ([Na+] + [Mg2+] + [K+] + [Ca2+]) almost 3.5 times lower than those draining the volcanic deposits (~1600 vs ~5600 µM). Despite the composition of the ophiolites consisting of highly weatherable mafic and ultramafic minerals, the volcanic deposits are seemingly even more favorably weathered. This is interpreted to be caused by the freshness of the material deposited from the recent eruption. Overall, our study shows that despite all rivers in this study draining highly weatherable lithologies, their intrinsic lithological differences can lead to significantly contrasting d7Lidiss and major cation signatures. New clay mineralogical data from riverine sediments will further inform us on silicate weathering processes in the region.
Unveiling Undisturbed Alpine Lake Ecosystems: A Multiproxy Approach to Reconstruct past Ecological Response to Climate Variability in the New Zealand Southern Alps
Authors: Eschenroeder Julian , Moy Christopher M. , Naeher Sebastian , Vandergoes Marcus J. , Rach Oliver , Sachse Dirk , Tjallingii Rik , Saunders Krystyna M. , Howarth Jamie D. , Shepherd Claire
Published: March 2024

Apart from natural variations in environmental and climatic conditions, human activities (e.g. land-use changes) can have major impacts on freshwater ecosystems. In the context of New Zealand, the arrival of humans approximately 750 years ago has left a permanent mark on landscapes, posing challenges in discerning undisturbed natural conditions for paleoclimatic reconstructions. Yet, remote alpine lakes in the Southwest Pacific can serve as pristine archives of environmental and climate changes, hardly influenced by human activities.This study focuses on sediment cores obtained from two neighbouring catchments of Lake Bright and Lake Laffy in Fiordland National Park, situated in an understudied remote area of New Zealand’s Southern Alps. Employing a multiproxy approach, we utilized bulk C and N stable isotopes, lipid biomarker analysis, and high-resolution X-ray fluorescence and hyperspectral imaging to reconstruct Holocene changes in catchment dynamics and climate. Here, we present a new precipitation record based on the compound-specific composition of hydrogen isotopes of plant wax n-alkanes as well as a branched glycerol dialkyl glycerol tetraethers (brGDGTs) derived temperature reconstruction. Examining a sequence spanning the late Holocene, we discern events of evolving environmental conditions impacting these catchments.Our biomarker paleorecord from Lake Bright revealed a relatively stable temperature range during the last 4 ka, indicating that the changes in the sedimentary record might be dominantly shaped by the local hydroclimate. The low compound δ2H values observed reflect precipitation that has been orographically uplifted over the Southern Alps. Downcore δ2H variations are likely influenced by changes in the isotopic composition of rainfall driven by regional temperature and latitudinal sources of westerly precipitation. In this context, we present these episodes of hydroclimatic variability and derive the ecosystem response to prevalent conditions by correlating the respective changes in lake productivity, water quality and shifts in vegetation composition.Finally, we extend this record through the Holocene to the last local glacial termination about 10 ka ago using the Lake Laffy stratigraphy and engage in a discussion regarding the potential implications of enhanced climate variability on the future integrity of New Zealand's pristine alpine ecosystems.
Exploring the dynamics of the Atmospheric Boundary Layer over the Western-Indian region: Insights and Implications.
Authors: Kamat Dharmendra , Sharma Som , Saha Sourita , Kumar Prashant , Kumar Niranjan
Published: March 2024

The Atmospheric Boundary Layer (ABL) represents the critical interface between the Earth's surface and the free atmosphere, playing a pivotal role in shaping weather patterns, air quality, and the dispersion of pollutants. This study comprehensively investigates the ABL dynamics over the Western-Indian region during 2019-2023. Continuous observation of ABL is made over the Western-Indian region's three locations: Ahmedabad, Mount Abu, and Udaipur. Ahmedabad (23.02° N, 72.57° E) is a highly polluted urban location in the Indian state of Gujarat with a hot, semi-arid climate, while Mount Abu (24.59° N, 72.71° E) is a high-altitude location in the Aravalli range of mountains in Rajasthan. On the other hand, Udaipur (24.58° N, 73.71° E) is close to the desert region in Rajasthan, surrounded by lakes and having a hot semi-arid climate. The ABL is continuously monitored over these stations using a ground-based Ceilometer lidar. By analyzing observational data collected from diverse geographical locations, we seek to identify regional variations in ABL characteristics and their consequences on local weather systems. Results indicated a large winter-summer difference in ABL over Ahmedabad, with summer Boundary Layer Height (BLH) exceeding winter BLH by 1–1.5 km. These differences were less over the Mount Abu and Udaipur region. The ABL usually collapses over all three study regions during monsoon and is thicker during the pre and post-monsoon. Ground-based observation of ABL using lidar has been compared with the radiosonde, satellite, and reanalysis datasets. The ERA5 reanalysis underestimated the BLH, especially the nocturnal boundary layer height. Due to the proximity to the Thar desert, the study sites witness dust storms. The study also investigated the impact of dust storms on the ABL. Through a combination of advanced measurement techniques, such as lidar and satellite observation, we aim to provide a nuanced understanding of the spatiotemporal variability of key ABL parameters. In conclusion, this study aims to contribute to understanding how the ABL responds to changing climate conditions and its role in modulating the Earth's energy balance. By enhancing our understanding of ABL dynamics, we can improve the accuracy of weather predictions, refine climate models, and develop strategies for mitigating the impact of air quality issues on human health and the environment.
Probing the Martian atmospheric boundary layer using impact-generated seismo-acoustic signals
Authors: Froment Marouchka , Xu Zongbo , Lognonné Philippe , Larmat Carene , Garcia Raphael F , Drilleau Mélanie , Delbridge Brent G , Spiga Aymeric , Kawamura Taichi , Beucler Eric
Published: March 2024

In-situ measurements of atmospheric variables are key to the validation and improvement of current models of the Martian climate, particularly of the planetary boundary layer. This highly dynamical region, whose thickness and altitude vary, is governed by unique thermodynamical, physical and chemical exchanges between the troposphere and surface. However, only sparse data is available in this location, as information is collected mostly by a few surface probes and during occasional spacecraft descent and landing. Recently, the seismometers of the InSight lander recorded short low-frequency, dispersed waveforms on six occasions. These signals were shown to be impact-generated guided infrasound waves. They were excited by the atmospheric entry and surface impact of bolides, and propagated  in a low-altitude atmospheric waveguide. The location of their source, i.e., the impact crater, is well characterized by orbital imaging and the origin time by joint seismic and acoustic analysis. The deformation of the ground by the propagating infrasound wave allowed their detection by InSight seismometers.Using analytical modeling, we show that the signal group velocity depends on the vertical profile of the effective sound speed in the Martian boundary layer. These impact-generated signals provide a unique opportunity to probe the atmosphere at these low altitudes. Here, we conduct a Bayesian inversion of effective sound speed up to  ~2000 m altitude using the group velocity measured for events S0981c, S0986c and S1034a. We compare these results with estimates of effective sound speed profiles provided by the Mars Climate Database based on global circulation models. We show that the differences between inverted and modeled profiles can be attributed to a local variation in wind in the impact → station direction, with amplitude smaller than 2 m/s, and that the infrasound data generally validates the Mars Climate Database results for each date and location.
Drivers and Impacts of Changing Subpolar North Atlantic Surface Temperature and Salinity
Authors: Josey Simon , Grist Jeremy , Sinha Bablu
Published: March 2024

Two aspects of Subpolar North Atlantic variability are explored using observations and model analysis. The first aspect is the autumn-winter seasonal reduction of sea surface temperature (SST). In a climate change simulation with the HadGEM3-GC3.1-HM model, a strong increase in the magnitude of the seasonal temperature reduction (STR) is found in sea-ice affected regions and the subpolar gyre. Similar results are obtained from an observational analysis using the HadISST dataset. In both cases, the STR has increased in magnitude by up to 0.3 ºC per decade over 1951-2020. The primary driver for the increased STR is a greater sensitivity of SST to heat loss due to increased surface stratification brought about predominantly by warming of the northern ocean regions. The increase in STR, leads to a greater winter meridional SST gradient, with potential consequences for increasing winter storminess. The second aspect is an investigation of the atmospheric impacts of surface salinity anomalies through modification of mixed layer properties and the surface heat exchange. For this analysis, the seasonal evolution of two 20-member ensembles of HadGEM3-GC3.1-HM have been undertaken with and without an imposed initial winter salinity anomaly in the western Subpolar North Atlantic that is similar in magnitude to the Great Salinity Anomaly. The evolution of the perturbed model runs will be examined with a focus on the consequences for European spring-summer climate conditions.
EarthCARE, ESA’s Cloud and Aerosol Mission, Preparing for Launch
Authors: Fehr Thorsten , Bernaerts Dirk , von Bismarck Jonas , Deghaye Patrick , Eisinger Michael , Frommknecht Björn , Hummel Timon , Koopman Robert , Rusli Stephanie , Wallace Kotska
Published: March 2024

The influence of clouds on incoming solar and reflected thermal radiation remains the largest contribution to the overall uncertainty in climate feedbacks due to the diverse cloud formation processes. Furthermore, climate models still show deficiencies in correctly representing aerosol-cloud interactions and precipitation patterns limiting the overall confidence in climate predictions.Global observations of vertical cloud ice and liquid water profiles with simultaneous and collocated solar and thermal flux observation will provide crucial data to address this uncertainty. Furthermore, collocated global observation of vertical aerosol profiles and types are required to address their direct effects and indirect aerosol-cloud-interaction effects.In response to these needs, the European Space Agency (ESA), in cooperation with the Japan Aerospace Exploration Agency (JAXA), plans to launch the Earth Cloud, Aerosol and Radiation Explorer Mission, EarthCARE – ESA’s Cloud and Aerosol mission – in May 2024.The two active instruments embarked on the satellite, a cloud-aerosol lidar (ATLID) and a cloud Doppler radar (CPR), together with the passive multispectral imager (MSI) and broad-band radiometer (BBR), will provide synergistically derived vertical profiles of cloud ice and liquid water, aerosol type, precipitation, as well as heating rates, solar and thermal top-of-atmosphere radiances with the objective to reconstruct top-of-the-atmosphere short- and longwave fluxes at an accuracy of 10 Wm-2 on a 10 km×10 km scene. The mission aims to significantly improve our understanding in the cloud and aerosol radiative feedback mechanisms, and their representation in climate and weather forecasting models.The presentation will provide an up-to-date overview of the mission and science status weeks before the planned EarthCARE launch on a Falcon-9 rocket beginning of May 2024 from Vandenberg, USA. It will cover the mission’s science objectives, main performances of the three ESA instruments, expected science advances and foreseen validation activities. A detailed presentation on the data products, ground processing and data quality assurance will be provided by T. Hummel et al. at EGU24.
Extratropical teleconnections in an ensemble of models nudged towards the observed equatorial QBO
Authors: Andrews Martin , Butchart Neal , Anstey James , Bednarz Ewa , Elsbury Dillon , Kumar Vinay , Palmeiro Froila , Trencham Natasha , Chai Zhaoyang , Tang Qi , Xie Jinbo , Lin Pu , Lott Francois , Watanabe Shingo , Jaison Aleena , Knight Jeff , Naoe Hiroaki , Yoshida Kohei
Published: March 2024

The Quasi-Biennial Oscillation (QBO) is the leading natural model of interannual variability of the zonal mean wind in the equatorial stratosphere, consisting of alternating regions of easterly and westerly zonal wind that descend through the equatorial stratosphere with a mean period of approximately 28 months. Its dominant influence on the dynamical structure of the equatorial stratosphere raises the prospect of teleconnections to the extratropical atmosphere. For example, the QBO has been linked to variability in the Northern Hemisphere winter stratospheric polar vortex, the timing and frequency of sudden stratospheric warmings, the phase of the North Atlantic Oscillation, and the modulation of tropospheric mid-latitude waves in the Pacific region. However, the reproduction of these extratropical teleconnections in free-running models relies upon on a quantitatively realistic internally-generated QBO, and the ability of the model dynamics to respond to this QBO. To isolate the dynamical response, a new experiment protocol, defined by the Atmospheric Processes and their Role in Climate (APARC) Quasi-Biennial Oscillation initiative (QBOi), describes how the observed equatorial stratospheric zonal winds can be imposed in model experiments. This allows the dynamical response across different models with similar and realistic QBOs to be analysed. Using a multi-model ensemble generated by QBOi modelling centres, we present an assessment of the extratropical teleconnections in comparison with observations.
Scientific challenges when using SAR images for mapping of water bodies and floods everywhere and anytime
Authors: Wagner Wolfgang
Published: March 2024

Synthetic Aperture Radar (SAR) satellites have emerged as the predominant information source for large-scale flood mapping, owing to their ability to map the Earth's surface regardless of weather conditions. Additionally, the classification of permanent water bodies and inundated areas from SAR images appears to be relatively straightforward given that calm water surfaces show up as dark patches in SAR images. Yet, a naïve approach to water body and flood classification from single SAR images can be misleading for many reasons. Firstly, in most environments SAR sensors under-detect the surface water extent due to challenging land cover and rough water surfaces. Secondly, there are water-look-alike surfaces such as tarmac or grasslands that are misclassified as water. Last but not least, the definition of permanent water bodies, wetlands, and floods is not trivial and only possible when using historic observations as reference. Some of this challenges can be addressed by experts when classifying only a limited set of SAR images. However, the difficulty significantly increases when attempting to map water bodies and floods in a fully automatic manner without prior knowledge of the environmental conditions. This becomes essential, for instance, when investigating the dynamics of wetland areas or the recurrence of floods over extended time periods or regions, or when employing SAR data for near-real-time flood monitoring. In this presentation, I will provide an overview of these challenges, drawing on the outcomes of research on this topic carried out at TU Wien over the last two decades and the preliminary experiences gained from the operationalization of the new fully-automated Sentinel-1 based Global Flood Monitoring service, which is operated as one of the components of the Copernicus Emergency Management Service.
Analysis of Antropogenic effects on the tidal dynamics and salt transport along the Guadalquivir river estuary.
Authors: Sirviente Alonso Sara , Gomiz Pascual Juan Jeús , Bolado Penagos Marina , Bruno Mejías Miguel
Published: March 2024

This study presents an analysis of the impacts of changes in bottom depth along the Guadalquivir Estuary on tidal dynamics. A realistic non-linear 1D numerical model, incorporating alterations in both breadth and bottom depth, was employed to investigate the associated effects.The 1D numerical model consists of a hydrodynamical model and a transport and dispersion module,which successfully reproduce the hydrodynamics of the saline intrusion from the continental shelf.The results show a significant amplification of the M2 tidal wave towards theheadof the Estuary,which seems to be caused bythe gradual bottom deepening caused by multiple dredging activities. The Estuary exhibits a pronounced tendency towards resonance, which is further enhanced by this deepening which reduces bottom friction and produces a smaller decrease in tidal wave amplitude as it propagates through the Estuary. The alterations in depth, particularly in breadth, along the Estuary play a crucial role in determining the magnitude of the resonant response of the M2 tidal wave.Modelsimulations demonstrate how changes in the geometric configuration of the channel, as well as the river waterwithdraw different agricultural activities, lead to significant alterations in the salt wedgedynamics. These changes in the tidal and associated salt exchange dynamics may also have a significant impact in thebiogeochemical exchanges between the river and the continental shelf, with potential harmful effect on the primary productionin the mouth of the estuary and adjacent coastal areas. 
Improvement of Korea Meteorological Administration insolation Information by Applying Detailed Terrain Data
Authors: Yun Jinah , Kim Jinwon , Choi Minwoo , Choi Hee-Wook , Kim Yeon-Hee , Lee Sang-Sam , Kim Ki-Hoon , Lee Chulkyu
Published: March 2024

  As the proportion of renewable energy continues to rise, solar energy reaching the Earth's surface holds a significant share compared to other sources such as wind power. Efficient utilization of solar energy necessitates accurate data on surface insolation. Consequently, both domestically and internationally, there's active research into developing insolation mapping using various numerical models based on solar meteorological resources.The Korea Meteorological Administration's KMAP (Korea-Meteorological Administration Post-processing), hereafter KM, provides insolation data. However, its limitation lies in the inability to realistically account for complex terrains like mountains due to the 1.5 km resolution of the Meteorological Administration's LDAPS (Local Data Assimilation and Prediction System), an operational local forecast model. This study analyzes the impact and characteristics of different resolutions of Digital Elevation Models (DEMs) on the accuracy of surface insolation calculations performed by KMAP-Solar, the solar energy mapping system of the Korea Meteorological Administration (1.5 km and 100 m). Comparison and verification against insolation data from 42 Korea Meteorological Administration Automated Synoptic Observation Systems (ASOS) stations reveal that the introduction of high-resolution DEM reduces land-averaged solar radiation biases by up to 32 Wm−2 at all observation points, particularly accentuating its effect in regions with complex terrains.The enhanced accuracy due to high-resolution DEMs is attributed to their ability to alleviate errors caused by differences in Sky View Factors (SVF) between high and low-resolution DEMs. Both DEM resolutions exhibit correlations between insolation and terrain elevation (SVF). However, high-resolution DEMs significantly underestimate these relationships compared to low-resolution DEMs, primarily in areas with high elevations where low-resolution DEMs inadequately represent steep terrains and/or small SVFs.This study demonstrates that high-resolution DEMs provide a more realistic distribution of insolation by integrating a broader range of crucial terrain parameters, thus proving their significance in accurate insolation calculations compared to low-resolution DEMs. It is anticipated that this research will play a crucial role in supporting future solar energy studies, real-time prediction, and management within solar power plant installations and the power grid.
Arctic Ocean freshwater export events and possible linkages with AMOC weakenings in the last 200 ka
Authors: Spielhagen Robert F. , Zehnich Marc , Bauch Henning A. , Kuhnert Henning
Published: March 2024

Deep-sea sediment cores from the Arctic Ocean are excellent archives suitable for the reconstruction of deglacial events on circum-Arctic continents and the associated enhanced export of freshwater to the North Atlantic. Here we present new records from a long large-volume sediment core obtained on the NE Greenland continental margin at 81.2°N where the shelf is particularly narrow. The site is perfectly located to monitor the export of freshwater and ice from the Arctic Ocean to the Greenland Sea using data on ice-rafted debris (IRD) and the stable isotope composition of planktic and benthic foraminifers in the sediments. The records from our new core hold evidence of a number of strong freshwater export events in the last 200 ka. Several events correlate in time with extreme discharges from large lakes which had developed south of the ice sheets on northern Eurasian shelves in MIS 6, 5b and 4. Using published data from the Greenland Sea and the North Atlantic, we can show that freshening events in the Arctic and the Nordic Seas correlate with weakenings of the Atlantic meridional overturning circulation (AMOC). We propose that enhanced Arctic Ocean freshwater export triggered (or contributed to) decreased deepwater renewal in the Greenland Sea and had severe consequences for the strength of the global ocean circulation.In addition to the Arctic Ocean freshwater events our new records reveal a number of probably minor events of iceberg melting and intermediate water freshening which we associate with the history of continental ice on North Greenland and in particular in the Wandel Sea. We propose that the repeated ice expansion and retreat in this area released dense plumes of fine-grained sediment and low d18O-water which spread along the continental slope. This may have happened in MIS 6, 5d, and 4. For the last 50 ka, our records suggest an ice retreat on North Greenland at 50-40 ka and a stepwise readvance of the ice front at 35-25 ka.
Reproducing flash flood warnings with Machine Learning
Authors: Zlydenko Oleg , Cohen Deborah , Gauch Martin , Gerzi Rosenthal Adi , Kratzert Frederik , Nearing Grey , Shalev Guy , Gilon Oren
Published: March 2024

Flash floods account for a large proportion of flood-based fatalities, and they are becoming more frequent due to climate change. A global flash flood warning system therefore has the potential to be life saving.Standard approaches to flash flood forecasting – such as the Flash Flood Guidance (FFG) system in the US National Weather Service (NWS), or the European Runoff Index based on Climatology (ERIC) in the European Flood Awareness System (EFAS) – are utilizing recent weather and soil conditions, physiographic characteristics of basins, and weather forecasts, in order to produce a forecast for possible flash floods. These forecasts are not disseminated directly to the public. Instead, they are firstly refined by hydrologists that have intimate knowledge of the relevant basins and of previous flood events. This introduces a difficulty to scaling these methods worldwide, as the training of professional hydrologists in every region is costly and time consuming.Recent applications of Machine Learning (ML) to hydrology show that a learning system has the potential to train on data-rich basins and generalize to data-poor basins, with a skill that is comparable to state of the art hydrological models. In this work we attempt to build a ML model to produce daily flash flood forecasts, based on globally available weather reanalysis and physiographic characteristics from HydroATLAS. We discuss the model architecture, and evaluate it against NWS Flash Flood Warnings (FFW). While such models may not surpass the skill of a professional hydrologist, they have the potential to provide reasonable warnings in regions that do not currently have any such system in place.
Future Exposure to Extreme Heat in Southeast Asia
Authors: Manimaran Sonali , Wagenaar Dennis , Nam Christine , Lierhammer Ludwig , Bouwer Laurens , Lallemant David
Published: March 2024

Southeast Asia has seen an increasing trend in extreme temperatures, with records of the highest surface air temperature being set in recent years. Heat waves are also increasing in frequency, severity and duration, with higher maximum temperatures being recorded both in daytime and nighttime. These trends are expected to intensify in the coming decades with climate change, with many implications for human health. For Southeast Asia, however, the number of studies quantifying future heat hazards and exposure are severely limited, but first analyses show that several countries in the region could see dramatic shifts in risk due to climate change. Therefore, it is imperative to quantify the heat stress that populations will be exposed to due to future extremes in the region. To this end, this study uses projections from Regional Climate Models to compute the Wet Bulb Globe Temperature (WBGT) and Universal Thermal Climate Index (UTCI) as measures of extreme heat. WBGT has been widely used in studies of extreme heat and impacts, particularly in the case of outdoor physical work, and has been shown to be representative of heat stress in hot and humid environments, such as Southeast Asia. On the other hand, the UTCI is a newer metric which has been demonstrated to be applicable in a range of climatic conditions and representative of the human physiological response. Using the novel CORDEX-CORE dataset for Asia, WBGT and UTCI metrics for Southeast Asia are developed at a 22x22 km resolution up till 2100 using a wide range of ensemble simulations. Future population exposure to extreme heat is then computed for each country in the region, across a range of Shared Socioeconomic Pathway (SSP) scenarios. Our first results show that nearly the entire region will experience strong heat stress by mid-century and some countries will experience strong heat stress for most of the year by the end of the century.
Verification Of Large Scale Dynamic Soil Model Tests Through Numerical Analysis
Authors: Çark Aslı , Bayat Esra Ece
Published: March 2024

This study presents numerical evaluation of large scale dynamic soil testing in a new laminar soil container setup. A dry sand sample was instrumented with embedded accelerometers and linear variable differential transformers (LVDT) connected to the container from an outside frame. The large scale soil sample was tested under dynamic sinusoidal and earthquake motions generated on the shaking table. The measured accelerations and LVDT data were processed and the free motion of the sand sample in the middle of the container at different depths was investigated. One dimensional site response of the soil sample was compared with a 1D soil model prepared in site response analysis software program DEEPSOIL v7.0. The results demonstrated that the measured accelerations in good agreement with the computed site response output data.
Internal Mass-Induced Elastic Deformation: A Semi-Analytic Approach    
Authors: Tang He , Sun Wenke , Ji Yuting
Published: March 2024

This research presents an innovative semi-analytical method to study the deformation of a viscoelastic, spherical, layered Earth model under periodic loading. We explore the effects of surface mass changes on deformation over various timescales, including annual and interannual, using a linear rheology profile. Our approach leverages a novel set of formulas in the spectral domain, linking mass, geoid, and displacement through complex Love numbers and Stokes coefficients. This technique bypasses the traditional reliance on viscoelastic Green’s functions.In our analysis, we particularly focus on the impact of annual cyclic mass loading on viscoelastic loading deformation. We consider both steady-state creep and additional transient creep across a broad spectrum of viscosities. Our findings reveal that while steady-state viscosity values, constrained by Glacial Isostatic Adjustment (GIA) data, show minimal viscoelastic impact on annual load deformation, the inclusion of transient creep, primarily informed by post-seismic data and modeled through the Burgers model, significantly alters the deformation's amplitude and phase. This underscores the importance of rheological properties in understanding Earth's deformation.Furthermore, our results demonstrate a notable difference in how the horizontal displacement, as opposed to geoid and vertical displacement, responds to viscosity changes. This disparity is observed regardless of the rheological model applied, indicating a greater sensitivity of horizontal displacement to viscosity variations in periodic load deformation. Our study provides new insights into the complexities of Earth's viscoelastic response to cyclic loading, contributing to a deeper understanding of geophysical processes.
Harvesting Global Oceanic Lead Data Using Machine Learning: Standardization, Alignment and Spatio-temporal Puzzle Assembly with Large Language Model
Authors: Liu Yiming , Liang Shiyu , Wang Xinbing
Published: March 2024

The scarcity and inherently challenging nature of acquiring observational data has long hampered our understanding of elemental lead (Pb) distribution across global oceans. Recent advancements in data mining and machine learning offer new directions to address this challenge. In this study, we capitalize on our team's existing data mining system, DataExpo, to collate Pb-related data sets accessible via the internet, aiming to depict a comprehensive picture of global oceanic Pb. The collected datasets are heterogeneous in nature, exhibiting variances across data descriptions, formats, and types due to disparate data sources. To facilitate congruity in data amalgamation, Llama2, a generative large language model (LLM), is used to achieve semantic understanding to standardize and align the differing data table headers. Following the standardization and alignment processes, the aggregated data are spliced according to geographical location and temporal period, creating a complete spatio-temporal puzzle of global oceanic lead. The ultimate portrayal of this panoramic view promises to shed light on the global cycling pathways of Pb within our oceans. Among the anticipated outcomes are the identification of origins of Pb contamination and the elucidation of potential cycling pathways. These findings are critical for targeted interventions to mitigate contamination effects and enhance our understanding of bio-geochemical processes. Further advancements in global oceanic lead estimates are foreseen through iterative enhancements of our generative large language model application methodology.
Using high resolution climate data to help prepare future energy systems for weather-driven extremes.
Authors: Bloomfield Hannah
Published: March 2024

Energy systems across the world are rapidly evolving to meet climate mitigation targets. This requires a rapid transition to electricity systems lower reliance on fossil fuels and greater weather-dependent renewable generation (such as wind power, solar power, and hydropower). This increased weather dependence adds a new set of challenges for balancing supply and demand due to the inherent variability of weather, increasing the need for investment in storage and flexible technologies. The impacts of climate variability and climate change on national energy systems is a topic of current academic interest. Both in terms of security of supply risks from system level challenges (e.g., energy shortfall events, where existing generation is insufficient to meet demand) or from smaller-scale infrastructure challenges (e.g., extreme weather impacting the operability of energy system components).This talk will discuss a programme of work on energy sector impacts using the UK Climate projections data (UKCP18). This is a suite of state-of-the-art climate model projections available at 60km resolution globally, 12km spatial resolution over Europe, and 2.2km resolution over the UK. Electricity demand, wind power, and solar photovoltaic power timeseries are developed for the period 1980-2080 using the regional climate model outputs. Climate data of this high spatial and temporal resolution is critical for the accurate quantification of meteorological hazards of relevance to the energy sector. The UK energy sector will be used as a case study in this talk due to its large share of variable renewables and commitments to reach net-zero emissions by 2050 and decarbonising the electricity system by 2035.This talk will highlight weather-driven risks to the energy sector in both a present and future climate, with a particular focus on compound events. At short timescales examples of these risks could be periods of high demand combined with low wind power generation, or weather patterns extending over a very large area of Europe (therefore creating a spatial compound event) or sequences of extreme weather (such as several storms happening in quick succession, which could damage energy infrastructure). At longer timescales these types of compound events could be years with low renewable energy production relative to demand, or as successive years with low production. Future work will use the years containing extreme events highlighted in this talk as inputs within high resolution power system modelling simulations. 
The potential of empirical mode decomposition to evaluate hydrological model simulations
Authors: Hoffmeister Svenja , Zehe Erwin
Published: March 2024

We explore the potential of the empirical mode decomposition (EMD), a signal-processing method, to evaluate hydrological model simulations. Usually, hydrological models are assessed in the time domain observing and comparing residuals on a point-to-point basis. An additional model evaluation in the frequency domain might provide useful and complementary insights about the model’s capability to reproduce dynamic system behaviour. EMD separates a signal (e.g. a soil moisture time series) into fast and slow oscillations based on a sifting process, in which subtracting the signals moving average from itself reveals the highest frequency oscillation. This allows for instance to analyse phase shifts of different signature modes (e.g. daily fluctuations) in different depths and by that to make assumptions on soil hydraulic properties such as the conductivity. Naturally, a model will always miss high-frequency components of the “real” signal as measurement devices used as model input already act as a filter of such. However, the ability to capture the lower frequency remains interesting as they include relevant hydrological processes. Advantages of EMD over traditional methods like Fourier or wavelet transform are that no prior assumptions are needed and that it works well for nonlinear or non-stationary signals.We test the EMD method on soil moisture and matric potential time series of observations and a process-based hydrological model extracted for the same site and compare the phase shifts and spectral components. We want to test whether metrics such as the RMSE of frequency spectra help to further compare and elucidate different signals. First results underpin the potential of including EMD as a tool to quantify models from a different perspective. We observe difference in observation and model frequencies of soil water time series and can related certain intrinsic modes to hydrological processes.
Connection of Summer Surface Temperature Anomalies between the East European Plain–West Siberian Plain and North America on the Interannual Timescale
Authors: Lv Chenyu , Lu Riyu , Chen Wei
Published: March 2024

This study identifies a significantly positive relationship between summer surface air temperature (SAT) anomalies over two remote regions in the Eurasian continent and North America during the period 1979–2021 on the interannual timescale. The former region includes the East European Plain and the West Siberian Plain, and the latter region includes the central and eastern North America. The regional-averaged summer SAT anomalies show a correlation coefficient of 0.66 between these two regions, which is significant at the 99% confidence level. This intercontinental SAT relationship can be explained by a wave-like pattern of circulation anomalies, which is the leading mode of upper-tropospheric circulation anomalies over the middle and high latitudes of the Northern Hemisphere in summer. Further analysis suggests that the sea surface temperature (SST) anomalies over the Pacific and North Atlantic in the preceding spring, being coupled with the leading mode of atmospheric circulation anomalies over the Pacific–Atlantic sector, persist into summer and affect the SATs in the two remote regions, resulting in the intercontinental SAT connection.
Combining meteorological and soil wetness information in machine learning modelling for landslide early warning
Authors: Halter Tobias , Lehmann Peter , Bast Alexander , Aaron Jordan , Stähli Manfred
Published: March 2024

Shallow landslides triggered by intense rainfall events pose a serious threat to people and infrastructure in mountainous areas. Regional landslide early warning systems (LEWS) have proven to be a cost-efficient tool for informing the public about the imminent landslide danger. These LEWS are often based on the statistical relationship between rainfall characteristics and landslide inventory information. Previous studies in Switzerland have demonstrated that periods of increased landslide danger are correlated with relative changes in volumetric water content measured at soil moisture stations across the country. In this study, we combine such soil moisture information (including soil water potential) with meteorological data to establish dynamic thresholds for the prediction of landslide probability in both time and space. We train a random forest classifier to separate between critical and non-critical rainfall events. The models are trained and tested on data measured at 136 locations across the entire country during the period from 2008 to 2023. Our trained algorithm allows us to quantify (1) the importance of different climate and soil wetness variables and (2) the benefits of integrating soil wetness and meteorological information within LEWS. We are confident that this study will improve the accuracy and reliability of landslide forecasting at a national scale and contribute to improved landslide risk management in areas with steep slopes.
Revealing the transition from brittle to ductile failure mode in Carrara marble through in-situ 4D X-ray imaging and acoustic emissions experiments
Authors: Prastyani Erina , Cordonnier Benoît , McBeck Jessica , Wang Lei , Rybacki Erik , Dresen Georg , Renard François
Published: March 2024

Rocks exhibit a brittle failure mode, leading to system-size failure through cataclastic faulting processes involving microfracture coalescence and frictional sliding, resulting in localized deformation. In contrast, the ductile failure mode can be described as a distributed deformation at the macroscopic scale, although there may be significant grain-scale heterogeneities. The transition between these two modes is an important research area because it is assumed to occur at the base of the seismogenic zone where large earthquakes may nucleate. Understanding strain evolution and partitioning between brittle and ductile failure modes may shed light on the preparation process for large earthquakes. To investigate the transition from brittle to ductile deformation, we performed two series of experiments on Carrara marble core samples: conventional triaxial experiments with acoustic emission recording at GFZ Potsdam, and dynamic in situ 4D X-ray imaging experiments on beamline BM18 at the European Synchrotron Radiation Facility.  Carrara marble is used as a rock model because this transition can be achieved at room temperature. We performed the experiments at room temperature and confining pressures between 5 and 100 MPa. For the synchrotron experiments, we segmented the images and implemented digital volume correlation (DVC) analyses between tomogram acquisitions to quantify the evolution of volumetric and shear strain components during the transition from the brittle to ductile regime. The results show that the transition is controlled by the dynamics of microfractures, even in the ductile regime. Below 40 MPa of confining pressure, deformation localizes along faults, particularly at 5 and 10 MPa. At 40 MPa, tomograms reveal the formation of a localized shear zone and macroscopically distributed deformation, resembling a semi-brittle regime. The DVC reveals the spatial extent of the strain directed into faults. A limited number of acoustic emissions recorded at this confining pressure revealed the prevalence of aseismic activity during deformation. Above 40 MPa, deformation shifts to a non-localized pattern at the core sample scale, involving the opening of microfractures, possibly due to the cataclastic flow mechanism accommodating this regime.
Tectonic driving mechanism of Quaternary rock-uplift and topographic evolution in the northern-central Apennines from linear inversion of the drainage system
Authors: Racano Simone , van der Beek Peter , Faccenna Claudio , Buleo Tebar Victor , Cosentino Domenico , Schildgen Taylor
Published: March 2024

The study of rock-uplift variations in time and space can provide insights into the processes driving the topographic evolution of mountain belts. The Apennine mountain chain of Italy, one of the more recently developed mountain belts in the Mediterranean region, has undergone a strong Quaternary rock-uplift phase, particularly in the north-central sector, which has shaped the present-day topography. It has long been recognized that drainage systems can record temporal and spatial variations in rock-uplift rates. Specifically, in detachment-limited systems with simple settings (e.g., no significant variations in drainage area over time, and catchments mostly draining perpendicular to regional structures), river profiles can be inverted to reconstruct their history of rock uplift. In this study, we present linear inversions of river profiles from 28 catchments along the eastern flank of the northern-central Apennines. These results are calibrated to infer rock-uplift rates by estimating the value of an erodibility parameter (K) from short-term incision rates and catchment-averaged erosion rates obtained from cosmogenic-nuclide data. Different approaches with constant and variable K have been applied to produce the rock-uplift model that best fits independent geochronological constraints about the uplift of the Apennine belt. Our findings suggest a spatially and temporally variable rock-uplift event that started around 2.5 to 3 Ma, following the last compressional orogenic phase and coinciding with the onset of extension. Furthermore, this rock-uplift pulse migrated southward at a rate of approximately 115 km/Myr. The highest rock-uplift rates (higher than 1.2 km/Myr) are observed in the region encompassing the highest Apennine massifs, such as the Laga Massif and the Gran Sasso Range. These results align with previous studies on Apennine paleoelevations, and they are consistent with numerical models and field evidence from other regions exhibiting rapid rock-uplift pulses and the migration of uplift related to slab break-off. Our results support the hypothesis of a break-off of the Adria slab under the central Apennines and its southward propagation over the last few million years.
Vorticity-gradient forces and a center-of-mass approach explain the mean and oscillatory motion of Jupiter's polar cyclones.
Authors: Gavriel Nimrod , Kaspi Yohai
Published: March 2024

The polar cyclones on Jupiter have been observed regularly since their discovery by the Juno mission in 2016. While the symmetrically spaced 9 and 6 cyclones at Jupiter's north and south pole (respectively) have largely maintained their locations, 5 years of Juno's observations showed oscillatory perturbations in their positions. In addition, an overall westward drift was measured for the cyclones at both poles. In this study, a mechanism for these motions is presented. This mechanism is driven by the known "beta-drift" effect, a poleward-westward acceleration experienced by cyclones under beta (the meridional gradient in planetary vertical vorticity). When considering the relative vorticity of other cyclones, in addition to beta, to evaluate beta-drift on each cyclone, the polar group of cyclones forms a dynamical system analogous to a system of springs. Using the Juno observations, we show that such a representation agrees well with the data describing the location and acceleration of the cyclones with time. In addition, a toy model, driven by such prescribed beta-drift forces, is able to reproduce motions similar to the observations.To explain the mean westward motion exhibited by the circumpolar cyclones in the north and south poles (4° and 7. 5° degrees longitude per year, respectively), we propose a center-of-mass approach. Using simulations, we show that the motion of cyclones in a group can be primarily divided into a contribution from beta and a contribution from the interactions between cyclones. When considering the group as a whole, their center of mass is only subject to beta, manifesting in a polar orbit of the group, which precesses westward. This precession is proposed as the mechanism for the westward drift of the individual cyclones. We conclude by showing observational evidence for this interpretation.