bluuebunny/crossref_metadata_2025 huggingface dataset:
Snapshots of Ireland’s Holocene climate and fauna from stalagmites
Authors: Ansberque Claire , Linderholm Anna , Mark Chris , Kylander Malin , McDermott Frank
Published: March 2024

Stalagmites are well-known as paleoclimatic archives, but recent work [e.g., 1,2] has also demonstrated their paleobiological potential as archives of ancient animal and plant DNA. Because of this property, stalagmites have the potential to provide information on how past climatic fluctuations have impacted land fauna, specifically cave fauna of which bats are key ecosystem services providers. The aim of this work is to use stalagmites to gain precisely such knowledge. With this endeavour, we acquired geochemical data (Sr/Ca, δ18O, δ13C) along the growth axis of three early Holocene stalagmites from Ireland, which we used for climatic and environmental reconstruction. In addition, we acquired ancient DNA data in stalagmite laminae, including those where climatic and environmental shifts were observed. Results of these analyses are presented here and include new U-Th-dated stable isotopic curves and ancient DNA data chronologically anchored to stalagmite-derived climatic records. We also discuss our analytical workflow and the pros and cons we faced while combining geological and biological data on stalagmites such as data acquisition resolution, stalagmite chemistry, and DNA data quality.[1] Stahlschmidt et al. (2019) Scientific Reports, 9, 6628. [2] Marchesini et al. (2023) Quaternary Research, 112, 180-188
The Precession Cycles in East Asian Stalagmite Records Before the MPT Constrained by Carbonate U-Pb Dating 
Authors: Kang Le , Hai Cheng , Wang Jian , Niu Xiaowen , Zhang Haiwei , Ruan Jiaoyang , Ning Youfeng , Zhao Jingyao , Li Youwei
Published: March 2024

The U-Pb geochronology of carbonates holds significant application value and potential in the field of geoscience. The Isotope Laboratory at Xi'an Jiaotong University has pioneered the development of Carbonate Laser Ablation and Dilution (LA&ID-MC-ICPMS) U-Pb dating techniques, based on research into Quaternary cave secondary carbonate geochronology. By combining the high spatial resolution and rapid analysis speed of the laser method with the controllable sample volume and high testing accuracy of the dilution method, a comprehensive system for Carbonate U-Pb geochronology testing has been established. Moreover, with advancements in in-situ laser and isotopic dilution techniques for Carbonate U-Pb dating, we conducted tests using the laser method on various carbonate standards, both domestic and international, achieving U-Pb age results consistent with standard values within the error range. This laboratory also reported, for the first time in China, high-precision laser U-Pb dating results for Quaternary cave secondary carbonates, in alignment with ages obtained via dilution methods in foreign laboratories. Furthermore, our laboratory's entire Pb background is currently at a world-class level (~10 pg), and the testing results for cave secondary carbonates are consistent within the error range with dilution methods abroad and the laser method in our laboratory, validating its accuracy. The laboratory has developed robust, high-precision laser and isotopic dilution techniques for Carbonate U-Pb dating, surpassing the limitations of U-Th dating. Through U-Pb dating and oxygen isotope analysis of stalagmite SB20 obtained from Sanbao Cave in Shennongjia, Hubei, our investigation reveals that SB20's growth period spans from 1.25 to 1.50 million years ago, depicting roughly 10 orbital cycles in δ18O. Consequently, we have established East Asia's inaugural δ18O record within the monsoon region, preceding the Mid-Pleistocene Transition (MPT). This novel stalagmite record affirms the predominant influence of low-latitude monsoons, driven by solar radiation forcing, on the East Asian region, showcasing discernible precession cycles. The current emphasis on global climate change research is substantial. By amalgamating prior scientific accomplishments, the interplay between the thermodynamic circulation system governed by ice volume in higher latitudes and the dynamic circulation system regulated by low-latitude monsoons shapes a multifaceted Earth scientific framework. This study furnishes pivotal evidence for the comprehensive exploration of a "high-low latitude" climate circulation theory in the context of climate orbital dynamics. Keywords: Carbonate U-Pb geochronology; MPT; Stalagmite records; precession cycles
Dissolved organic carbon dynamics in a changing ocean: A COBALTv2 Earth System Model analysis
Authors: Flanjak Lana , Wienkers Aaron , Laufkötter Charlotte
Published: March 2024

Dissolved organic carbon (DOC) is a substantial pool of bioreactive carbon in the ocean, comparable in quantity to the atmospheric inorganic carbon reservoir. DOC plays an important role in the marine carbon cycle; its contribution to total organic carbon export corresponds to about 20%. Current modeling studies suggest a broad range of DOC surface concentration estimates, and the response of DOC concentration and export to climate change is unclear and has not yet been described in an Earth System Model. To address this knowledge gap, we make use of the ocean biogeochemistry and ecosystem model COBALTv2. We analyze DOC dynamics and export under the present and future climate conditions within the high-emission scenario. The COBALTv2 model, coupled to the GFDL’s ESM2M Earth System Model, enables us to trace DOC from its primary sources, including phytoplankton activity and grazer-prey dynamics, to its sinks such as bacterial remineralization. We also account for the physical processes such as advection that influences DOC distribution. Preliminary findings suggest that the current distribution of DOC in the ocean may undergo significant changes, contingent upon the biological sources and sinks that are sensitive to ocean temperature increases. The relative contributions of different phytoplankton groups to DOC production are expected to shift across various ocean regions, along with the magnitude of heterotrophic respiration, which is the predominant DOC sink. This study contributes to understanding and forecasting of potential shifts in oceanic DOC dynamics under current and future climate conditions.
Three-dimensional analysis of air temperature of the Hualien M6.9 earthquake based on the tidal forces
Authors: Lu Xian , Ma Weiyu , Yuan Zhengyi
Published: March 2024

The Hualien M6.9 earthquake on September 18, 2022 was calculated based on the additional tectonic stress caused by celestial tidal-generating forces (ATSCTF) model. The period of celestial tidal-generating forces was the time background of the air temperature calculation, and the air temperature variation of three-dimensional layered before and after the Hualien earthquake was studied combined with the air temperature data from the National Center for Environmental Prediction (NCEP) of United States. According to the changes of ATSCTF, the Hualien earthquake occurred within the Period B among the three periods: Period A, Period B, and Period C. The air temperature stratification changes during these three periods were calculated separately, and the results showed that on September 12 in Period B, a temperature increase phenomenon began to occur near the epicenter of the Hualien earthquake. On September 13, the air temperature increase anomaly was significant, and the amplitude and area of the temperature enhancement anomaly increased. On September 14th and 15th, the anomaly gradually weakened and disappeared, and the change of the air temperature anomaly followed the seismic thermal anomaly law caused by tectonic movement: the air temperature closer to the land’s surface had a greater anomaly amplitude and a wider anomaly range; as the altitude increases, the air temperature gradually decreases, and the range of anomalies gradually reduces until it disappears. Meanwhile, there were also high temperature anomalies on September 4 and 5 in the Period A, as well as October 1 to October 4 in the Period C. However, the amplitude and area of the warming anomalies in the upper atmosphere were larger than those near the land surface, which did not conform to the seismic thermal anomaly law caused by tectonic movements and did not belong to the seismic thermal anomalies. In addition, the solar geomagnetic KP index in the study area was relatively low during Period B, indicating that it was in a calm period of solar geomagnetic.
Introducing the Scottish Scientific Robotics Academy as a facility for testing and operating robotics for Ocean-Atmosphere Interaction studies.
Authors: Anderson Philip , Peterson Phil , Smith Libby
Published: March 2024

Understanding of global climate and the accurate forecasting of extreme weather in Europe rely on the validity of operational coupled atmosphere-ocean models over the north Atlantic. Robotic systems will play an increasing dual role in improving these models. Firstly climate models require improved parameterization schemes of the air-sea coupling, especially under existing data-sparse or data-disturbed conditions such as storm conditions or stratified turbulence respectively. Secondly, forecast model accuracy can be enhanced by targeted data assimilation, although this, at present, is costly.The SRA, based at the Scottish Association for Marine Science with association with Oban Airport, is ideally placed geographically, logistically and academically to test and deploy air-sea interaction technology in the immediate and medium term.We encourage academic and engineering collaboration from Europe and elsewhere to engage with the SRA to partner in the development of sensor and platform technology, validation of heterogenous swarms (airborne, surface and sub-surface) and trial operational studies.
Numerical diffusion and turbulent mixing in convective self-aggregation
Authors: Silvestri Lorenzo , Saraceni Miriam , Bongioannini Cerlini Paolina
Published: March 2024

Spontaneous aggregation of deep convection is a common feature of idealized numerical simulations of the tropical atmosphere in Radiative-Convective Equilibrium (RCE). However, at coarse grid resolution where deep convection is not fully resolved, the occurrence of this phenomenon is highly sensitive to subgrid-scale processes. This study investigates the role of mixing and entrainment, provided by either the turbulence model or the implicit numerical dissipation, in this phenomenon. The results of two different models, WRF and SAM, have been analysed and compared using different configurations by varying the turbulence models, initial conditions, and horizontal spatial resolution. At a coarse grid resolution of 3 km, the occurrence of Convective Self-Aggregation (CSA) is prevented in models with low numerical diffusivity due to the removal of turbulent mixing, while it is preserved in models with high numerical diffusivity. When refining the horizontal grid resolution to 1 km, which reduces the implicit numerical dissipation, CSA can only be achieved by increasing explicit turbulent mixing. Even with a small amount of shallow clouds, CSA was found to occur in this case. Therefore, this study suggests that the sensitivity of CSA to horizontal grid resolution is not primarily due to the corresponding decrease in shallow clouds. It has been found that the amplitude of initial humidity perturbations introduced by convection in the free troposphere is regulated by turbulent mixing and dissipation at small scales. The size and strength of humidity perturbations in the free troposphere that can destabilize the RCE state increase with greater dissipation at small scales.
The JSTIM-DARA  product derived from the TSI Observations Recorded by the FY3E/JTSIM/DARA Radiometer
Authors: Montillet Jean-Philippe , Finsterle Wolfgang , Haberreiter Margit , Pfiffner Daniel , Zhu Ping , Wu Duo , Koller Silvio , Ye Xin , Yang Dongjun , Fang Wei , Qi Jin , Zhang Peng
Published: March 2024

Since the late 1970s, successive satellite missions have been monitoring solar activity and recording Total Solar Irradiance (TSI) data. The Digital Absolute Radiometer (DARA) on board the Chinese FY3E spacecraft was launched on July 4, 2021, and  has since been recording TSI observations. Here, we analyze these observations and assess the performance of DARA, including sensor degradation of 5 ppm after 2 years in orbit, resulting from exposure to ultraviolet and extreme ultraviolet radiation. Comparing the new dataset’s mean values with observations from active  instruments on other spacecraft (i.e., PMO6 on board the VIRGO/SOHO and the TIM/TSIS), along with the Solar Irradiance Absolute Radiometer (SIAR) also on board  FY3E/JTSIM, we find that DARA observations closely align with TIM/TSIS, with a difference of approximately 0.07 W/m2. Based on these findings, we generate a new TSI dataset (JTSIM-DARA product) at a 6-hour sampling interval. Finally, we have incorporated this new dataset into the TSI composite time series released by the PMOD/WRC. The results indicate that the inclusion of DARA-recorded observations does not alter the consistency, reliability, and stability of the time series.
Gross Nitrogen Transformation: Insights from 15N Tracing in a Gas Sampling Incubation Experiment
Authors: Hafiza Barira Shoukat , Wanek Wolfgang , Vlasimsky Magdeline , Zaman Mohammad , Dercon Gerd , Heiling Maria , Resch Christian
Published: March 2024

Nitrous oxide (N2O) stands out among greenhouse gases due to its global warming potential, surpassing carbon dioxide by 310 times and methane by 16 times over a 100-year period. Its primary source lies in the application of fertilizers to agricultural soil. Despite its significance, traditional methods for understanding the intricate relationships within gross nitrogen (N) transformation processes are limited in their analytical depth.Current research increasingly centers on the N2O/(N2O+N2) product ratio, offering valuable insights into the efficiency of nitrogen transformations and the potential for N2O emissions. Quantifying both gases, however, poses challenges that demand specialized techniques. Leveraging isotopic methods, such as the introduction of enriched NO3− and monitoring 15N labelled denitrification products, proves instrumental in unravelling N2O sources and facilitating emission mitigation strategies.This study aims to contribute to this knowledge by measuring N2O and N2 and identifying their sources using a 15N tracer. Soil samples were collected from a 0-15cm depth at Grabenegg, an agricultural site in Austria. Two treatments were applied, with 15NH414NO3  for treatment one and 14NH415NO3 for treatment two, both at a rate of 100 kg N/ha (equivalent to 150 kg N/ha when expressed as 100 mg N/kg soil). The incubation experiment spanned 10 days in 850ml glass jars at 60% WFPS, involving seven sampling days. Soil analyses included ammonium and nitrate content through colorimetric methods, pH determination, and 15N analysis using an Isotope Ratio Mass Spectrometer (IRMS) following an adjusted Brooks microdiffusion.Gas samples extracted from the jars over a two-hour period underwent analysis for CO2, CH4, and N2O content using a Picarro G5102-i isotopic and gas concentration analyzer. Integration with N tracing models yielded crucial insights into the connections between substrates and N transformation products, shedding light on the impacts of synthetic fertilizer and enabling the quantification of transformation rates.
A proxy system model framework for reconstructing past environmental conditions with cosmogenic noble gases
Authors: Tremblay Marissa M. , Bourikas Taylor , Bergelin Marie , Balco Greg
Published: March 2024

Cosmogenic isotopes of helium and neon are produced at the Earth’s surface and exhibit a wide range of thermal sensitivities in common minerals. We can take advantage of this range of thermal sensitivities to reconstruct past near surface thermal conditions using cosmogenic noble gas observations. For example, cosmogenic noble gases have been used to study past ambient temperatures, changes in snow cover duration, and wildfire histories. Interpreting cosmogenic noble gas observations requires a model of both production and diffusion that predicts cosmogenic noble gas concentrations for different thermal histories. Additionally, models that characterize the diffusion kinetics of helium or neon in a particular mineral sample are often needed, as laboratory-based diffusion experiments demonstrate that helium and neon diffusion kinetics are sample specific and often complex. At present, various codes are available that can carry out pieces of the modeling, but they are generally not interoperable and are often highly specific to a particular past application, limiting the codes’ use for future applications. Here we present progress on creating a general forward modeling framework for inferring thermal histories using cosmogenic noble gas observations, structured around the concept of proxy system modeling. We will describe the architecture of this model framework as well as provide examples of applying it to new and existing cosmogenic noble gas datasets.
Time-domain denoising of CSAMT data base on long short-term memory
Authors: An Zhiguo , Xu Bingcheng , Han Ying , Ye Gaofeng
Published: March 2024

Controlled-source audio-frequency Magnetotellurics method (CSAMT) partially overcomes the drawbacks of weak natural field signals. However, substantial interference is an inevitable part of field surveys in practice, which negatively impacts signal quality. We require new denoising techniques since traditional techniques, such as Fourier transformation, which compute apparent resistivity directly from frequency-domain data, are insufficient in our situation. CSAMT denoising research is currently lacking, nevertheless. This research proposes the use of long short-term memory (LSTM) neural networks to denoise CSAMT signals in the time domain, given their good performance in processing Magnetotelluric (MT) data as shown by prior studies. We seek to directly extract the desired frequency signal for denoising from the time series data, in contrast to conventional denoising techniques. Since noise and target frequency signals are mixed together in MT data, the only way to suppress noise is to find the characteristics of the noise in the time series. CSAMT, on the other hand, differs from MT in that it uses an artificial transmitting source and fixes the valid signal frequency within a temporal window. This makes it possible to extract target frequency signals directly without taking into account the intricate properties of noise. In order to complete the noise suppression job, we created a neural network in this study that is based on bidirectional LSTM. This method was able to partially handle the difficulty of denoising when the data's SNR falls below 0 dB and, on average, enhance the signal-to-noise ratio (SNR) of CSAMT data by roughly 20 dB after executing both simulated and measured data testing.
Benchmarking Deep Learning based Downscaling of Wind Speed
Authors: Schmidt Luca , Ludwig Nicole
Published: March 2024

The efficient placement of wind turbines relies on strategic assessment of local wind speed. Recentstudies highlight the crucial role of spatial resolution in accurately forecasting wind speed andestimating the associated wind energy potential [1].However, climate models typically fail to provide the spatial data resolution necessary for preciseenergy resource assessment. To address this challenge, various downscaling methods have beenproposed to infer high-resolution data from coarser resolution data. Notably, image super-resolutionmethods, a class of image processing techniques originally developed in computer vision to enhancethe resolution of natural images, have emerged as a promising approach for statistical downscaling. By interpreting gridded data as images, these techniques are amenable to increasing the spatial resolution of climate [3] and weather data [2].We provide a comprehensive benchmark to compare the performance of various state-of-the-art imagesuperresolution models on weather data, such as ERA5 reanalysis data. The benchmark ranges frominterpolation baselines to all prominent deep learning based models, including a CNN-based model,an attention-based model and a spatio-temporal model. [1] Jung, C. and Schindler, D. [2022], ‘On the influence of wind speed model resolution on the global technicalwind energy potential’, Renewable and Sustainable Energy Reviews 156, 112001.[2] Kurinchi-Vendhan, R., Lütjens, B., Gupta, R., Werner, L. and Newman, D. [2021], ‘Wisosuper: Bench-marking super-resolution methods on wind and solar data’, arXiv preprint arXiv:2109.08770 .[3] Stengel, K., Glaws, A., Hettinger, D. and King, R. N. [2020], ‘Adversarial super-resolution of climatologicalwind and solar data’, Proceedings of the National Academy of Sciences 117(29), 16805–16815. 
Little glacial/interglacial net change in Southern Ocean bioproductivity over termination II - an integrated sulfate isotope ice core perspective
Authors: Fischer Hubertus , Burke Andrea , Ray James , Sugden Patrick , Wolff Eric , Pryer Helena , Doyle Emily , Severi Mirko , Markle Bradley , Hörhold Maria , Freitag Johannes , Twarloh Birthe , Erhardt Tobias
Published: March 2024

Glacial export productivity in the glacial Southern Ocean may have been enhanced due to iron fertilization from aeolian dust input. Marine sediments indicate such a glacial increase north of the modern Antarctic Polar Front but reduced biogenic activity and reduced nitrogen supply by upwelled deep waters south of it. Due to the sparsity of Southern Ocean sediment data, deriving an overall estimate of marine productivity changes is, however, difficult to achieve. Due to their larger spatial footprint, additional information on basin-wide productivity changes can be obtained from marine biogenic aerosol tracers in Antarctic ice cores.We use SO42- concentrations and its sulfur isotopic composition as well as other geochemical tracers in the EPICA Dronning Maud Land (EDML) ice core in the Atlantic Sector of the Southern Ocean (AS-SO) to provide the first complete glacial/interglacial source decomposition of total SO42- from the penultimate glacial to the last glacial inception. Our isotopic source decomposition shows that despite other (e.g. terrestrial) sources being significant contributors to total SO42- during glacial times, biogenic SO42- production is always the dominant source at EDML. Using information on recent dimethylsulfide emissions and aerosol forward modeling, we can show that biogenic sulfate recorded in the EDML ice core is derived from the AS-SO south of 35°S but the major source lies south of 50°S, i.e., mainly the seasonal sea ice zone. During the penultimate glacial these sources shifted about 4° northward in parallel to sea ice expansion.Taking reduced wet deposition of biogenic sulfate aerosol during glacial times into account, we can show that the biogenic sulfate production during the Penultimate Glacial Maximum and the Last Interglacial integrated over the AS-SO may have been only slightly higher in the penultimate glacial and differed by less than 15%. We see millennial biogenic sulfur changes of the same order during the Last Interglacial, which we attribute to temporal changes in the seasonal sea ice zone. An early interglacial productivity minimum in our biogenic sulfate record parallels within age uncertainties features previously reported in the literature, i.e., a minimum in winter, thus seasonal, sea ice extent, a stagnation event in Antarctic Bottom Water and a maximum in summer surface temperature encountered during the early LIG.
Uncertainty in Digital Soil Mapping at broad-scale: A review
Authors: Chen Qianqian , Richer-de-Forges Anne , Chen Songchao , Vaudour Emmanuelle , Bispo Antonio , Arrouays Dominique
Published: March 2024

With the needs of efficient acquisition of soil information, Digital Soil Mapping (DSM) has been greatly developed and widely applied for over the past two decades. The spatial estimates of soil properties produced with diverse methods over various study areas, have been often seen as the main output of DSM, as they play an important role in environmental modelling and policy. However, compared with the soil property maps, their prediction uncertainty is still less emphasized, which may potentially lead to mis-uses of results and inappropriate decisions if the uncertainty is not assessed, reported, and taken into account by end-users.In this communication, we present a preliminary review of the sources of prediction uncertainties in DSM coming from learning soil data (data source, sampling in space and time, measurements), covariates, and models. We also summarize the methods used to estimate the uncertainty, and to assess the reliability of the uncertainty estimates. We also consider the propagation of uncertainties when several soil attributes are combined to derive information and/or used as inputs for modelling. Furthermore, we discuss some strategies for mitigating the uncertainty, challenges, and future perspectives. This review aims to consolidate the understanding of DSM uncertainties and to contribute to reliable DSM practices, facilitating more informed decision-making in soil-related research and management. 
Determining the influence of fluorescent primary biological aerosol particles on low-level Arctic clouds
Authors: Zieger Paul , Pereira Freitas Gabriel , Kopec Ben , Adachi Kouji , Krejci Radovan , Heslin-Rees Dominic , Yttri Karl Espen , Hubbard Alun , Welker Jeffrey M.
Published: March 2024

Mixed-phase clouds are integral to the Arctic climate system as they regulate the energy transport to and from the surface. Their ice content, which influences the cloud's optical and physical properties, is regulated by the presence of ice nucleating particles (INP).  Despite this, knowledge of the sources and concentrations of INP in the Arctic is notably lacking.  Here, we investigate the abundance and variability of fluorescent primary biological aerosol particles (fPBAP) within cloud residuals at a key site at 79° North over an entire year. fPBAP have been found to be active INP at warmer temperatures. Samples were continuously collected using a multiparameter bioaerosol spectrometer coupled to a ground-based counterflow virtual impactor inlet at the Zeppelin Observatory in Ny-Ålesund, Svalbard. We found that fPBAP concentrations within cloud residuals closely aligned with the expected concentration of high-temperature INP. Transmission electron microscopy confirmed the presence of fPBAP, likely bacteria, in the cloud residual samples. Seasonal analysis demonstrated a higher presence of fPBAP within cloud residuals over the summer, with water vapor isotope measurements revealing a connection between summer cloud formation and regionally sourced air masses. Low-level MPC were predominantly observed at the beginning and end of summer, possibly due to the presence of high-temperature INP. Our study - currently under interactive discussion* - provides observational evidence supporting the role of fPBAP in determining the phase of low-level Arctic clouds, with implications for the composition of respective cloud condensation nuclei sources in the future under rapid Arctic climate and environmental change.*Pereira Freitas, G., Kopec, B., Adachi, K., Krejci, R., Heslin-Rees, D., Yttri, K. E., Hubbard, A., Welker, J. M., and Zieger, P. 2023: Contribution of fluorescent primary biological aerosol particles to low-level Arctic cloud residuals, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-2600.
Patterns and influencing factors of glacier changes in High Mountain Asia since the Little Ice Age
Authors: Li Yingkui
Published: March 2024

High Mountain Asia (HMA) contains the largest glacier inventory outside the polar regions and the melting of these glaciers provides an important freshwater supply for over 250 million people in south, central, and east Asia. Recent studies have quantified glacier changes over the past decades in this area mainly based on the interpretation of satellite imagery, while few studies have investigated the longer-term (centennial-scale) glacier changes due to the lack of mapped outlines and reliable methods to reconstruct the three-dimensional surfaces and volumes of past glaciers. We compiled a dataset of >15,000 mapped glacier outlines during the Little Ice Age (LIA) in the Himalayas, Gangdise, Tanggula, and Tian Shan and reconstructed the ice thickness and volumes of LIA glaciers and their corresponding contemporary glaciers based on a flowline-based GIS model, PalaeoIce. Initial results of 640 LIA glaciers and their corresponding 1466 contemporary glaciers from Tian Shan indicate a total of 47.6% loss of ice volumes since the LIA and the ice volume loss are negatively correlated with glacier area and equilibrium line altitude. This presentation reports the reconstruction of >15,000 LIA glaciers and their corresponding >20,000 contemporary glaciers in the four mountain ranges (Himalayas, Gangdise, Tanggula, and Tian Shan) to examine the spatial pattern of LIA glacier changes and their influencing factors (climate, topography, and debris cover). This work provides important insights into the impacts of glacier changes on water resources in High Mountain Asia in the past 300-500 years.
Variability in the Arctic Ocean currents during 1990-2
Authors: Wei Xiaoyan , Wilson Chris , Bacon Sheldon , Barton Benjamin
Published: March 2024

The Arctic Ocean is changing rapidly due to climate change, with significant impacts on subpolar ocean dynamics and mid-latitude regional weather. By utilizing a global, 1/12 degree, ocean sea-ice model (NEMO-SI3), which is forced at its surface by an Earth System Model, UKESM1.1, and simulates from 1981 to 2100 under scenario SSP3-7.0, we will demonstrate significant differences in the spatial structure and energy spectrum of Arctic Ocean currents among the past, the present, and the future. We will then explore the implications of changes in Arctic Ocean currents on mass transport pathways within the Arctic and transport across its boundaries. Subsequently, our study will identify the dominant physical drivers of these changes, such as sea ice melting, freshwater discharge, wind stresses, surface heat fluxes, and tides.
Influence of Ganymede's electron environment as measured by JADE on Ganymede's atmosphere
Authors: Vorburger Audrey , Fatemi Shahab , Carberry Mogan Shane R. , Galli André , Liuzzo Lucas , Poppe Andrew R. , Roth Lorenz , Wurz Peter
Published: March 2024

Ganymede’s atmosphere is one of the most complex among the moons of our solar system. As the only known satellite in our solar system to feature an intrinsic global magnetic field, Ganymede forms a small magnetosphere within the much larger magnetosphere of Jupiter. The interaction between the two magnetospheres makes Ganymede's plasma environment highly variable both in space and time. Consequently, the moon's atmosphere, predominantly shaped by the interplay between the plasma environment and Ganymede's surface, likely exhibits a corresponding high degree of variability.The recent Juno spacecraft flyby of Ganymede has provided us with unprecedented insights into the moon's electron and ion environment. This study capitalizes on electron data collected by the Jovian Auroral Distributions Experiment (JADE) during Juno's traversal of Ganymede's magnetopause current layer, employing these measurements as a proxy for the electron conditions within Ganymede's auroral region. Our simulations reveal that these electrons play a pivotal role in governing Ganymede's H2 and O2 atmospheres, representing the predominant constituents of its atmospheric composition. Furthermore, the abundance of atomic O and H, crucial factors in Ganymede's atmospheric mass loss, is intricately influenced by these electrons, underscoring their significance in shaping the complex dynamics of Ganymede's atmospheric behavior.Our current understanding of Ganymede's atmosphere predominantly stems from spectroscopic observations. However, it's crucial to acknowledge that the interpretation of spectroscopic data heavily relies on certain assumptions. Our analysis underscores the significance of acquiring a comprehensive understanding of Ganymede's atmosphere. To achieve this, it is imperative to conduct simultaneous observations encompassing the moon's surface, its atmospheric conditions, and the entirety of its plasma environment, including both thermal and energetic ions and electrons. 
Local thermal non-equilibrium (LTNE) effects revealed through porous media heat transport experiment
Authors: Lee Haegyeong , Gossler Manuel , Zosseder Kai , Blum Philipp , Bayer Peter , Rau Gabriel
Published: March 2024

Precise prediction of heat transport in porous media holds crucial significance in Earth Sciences for diverse applications, ranging from the design of geothermal systems to utilizing heat as a tracer in aquifers. Traditionally, the description of heat transport has been simplified by assuming local thermal equilibrium (LTE), where the temperature within the fluid and solid phases in the representative elementary volume is presumed to reach an instant equilibrium. In reality, assuming two distinct phases coupled by heat transfer across their surface area describes the complete physics and is referred to as the local thermal non-equilibrium (LTNE) model. While earlier research delved into the theoretical aspects of LTNE effects, a notable gap exists due to the absence of experimental data to elucidate the heat transport mechanism in porous aquifers containing natural grains. To address this gap and investigate LTNE on a granular scale, we conducted systematic flow-through experiments employing porous media containing glass spheres with distinct grain sizes of 5, 10, 15, 20, 25 and 30 mm. Each sphere contained a small temperature sensor for the solid temperature, accompanied by sensors in the adjacent pore space to measure the fluid temperature. Our findings revealed that the temperature difference between two phases grows with increasing grain size and flow velocity ranging from 9 to 61 m d-1, thereby highlighting qualitative LTNE effects in relation to grain size and flow velocity. To further enhance our understanding, we used a numerical model to investigate the heat transfer coefficient, fitting the LTNE model to the experimental data. These simulation results indicated evidence of non-uniform flow which we included into our model to estimate its effects on heat transport. This comprehensive approach contributes valuable insights into the intricate interplay of LTNE effects, grain sizes, and flow velocity, advancing our understanding of heat transport in natural porous media.
A new scenario for widespread solar energetic particle events based on multi-spacecraft observations of the 13 March 2023 event
Authors: Dresing Nina , Jebaraj Immanuel , Palmerio Erika , Palmroos Christian , Cohen Christian , Mitchell Grant , Lee Christina , Wei Wenwen , Asvestari Eleanna , Jarry Manon , Muro Gabriel , Rodríguz-García Laura , Wijsen Nicola
Published: March 2024

We report on multi-spacecraft measurements of a solar energetic particle (SEP) event that occurred on 13 March 2023. The Parker Solar Probe (PSP) mission was situated on the far side of the Sun as seen from Earth at a radial distance of only 49 solar radii and observed a very strong event including the associated CME and its shock passing over the spacecraft only four hours after the solar eruption. Solar Orbiter, BepiColombo, STEREO A, near-Earth spacecraft, and MAVEN at Mars were all situated within 50 degrees in longitude, and observed the event as well, proving its widespread character. Clear signatures of shock-driven energetic storm particle events were present at Solar Orbiter, STEREO A, and near-Earth spacecraft suggesting that the interplanetary CME-driven shock had a longitudinal extent of about 160 degrees. However, the solar event was accompanied by a series of pre-event CMEs and comparison with ENLIL simulation results suggest that the ESP events were associated with shocks driven by other CMEs. This scenario of particle re-acceleration at different pre-event-associated shocks, provides a new scenario for the generation of widespread SEP events. 
Validation and benchmarking of simplified reactive transport models of radionuclides for the assessment of nuclear waste repositories
Authors: Shao Haibing , Selzer Philipp , Behrens Christoph , Lehmann Christoph , Kreye Phillip , Rühaak Wolfram , Kolditz Olaf
Published: March 2024

Finding the best-suited location for safely storing high-level nuclear waste is more than a scientific challenge for a country. In Germany, the legal requirements demand a safe containment of high-level nuclear waste for at least one million years within a deep geological repository. In this context, the site selection procedure demands a validated model to predict the reactive transport of radionuclides in layered subsurface formations with varying physical and chemical properties. In this work, we compare the modelling capabilities of TransPyREnd, which is a one-dimensional transport code based on finite differences, especially developed for the quick estimation of radionuclide transport, with an established geoscientific simulator OpenGeoSys, which is capable of coupled thermo-hydro-mechanical-chemical modelling based on finite elements in three spatial dimensions. Both codes are going to be used in the site selection procedure for the German nuclear waste repository. The example host rock formation for benchmarking is the Opalinus clay located in southern Germany, which is modelled using a simplified and preliminary parametrization. We enhance the validation analysis by also benchmarking against an analytical solution for a homogeneous material. The modelling results suggest that both TransPyREnd and OpenGeoSys are capable of consistently modelling the distribution of radionuclides within the geological barrier over long timescale. The discussion further goes to the applicability of different approaches for serving as tools in the site selection procedure, with minor differences in their predictive capabilities, limitations, and possible pitfalls to be avoided for the accurate prediction of radionuclide transport over geological times.
A case study integrating in-situ monitoring data and numerical simulation method to slope stability assessment of a remote village in southwest Taiwan
Authors: Hsu Huai-Houh , Chen Ting-Wei , Hsieh Chen-Hsun , Chang Chia-Chi , He Tsung-Yi
Published: March 2024

The Baoshan Village, a remote village deep in southwest Taiwan, is located near the Tengjhih National Forest Recreation Area. The strata at the site of this study belong to the Miocene Changshan Formation. Its lithology is mainly slate, occasionally intercalated with thin sandstone layers, and the Chaochou Fault passes through it on the east side. Headward erosion and weathering effects made landfall while heavy rainfall and typhoons hit Taiwan. Typhoon Morakot (2009) impacted Taiwan and brought catastrophic damage. Landslides and significant damage happened in the Baoshan Village neighborhood. This study compiles the long-term in-situ monitoring data of the Baoshan Village from 2018 to the present. Monitoring results show that the east side of the Baoshan Elementary School has an apparent slide surface at a depth of 46m. The limit equilibrium method is adopted for the numerical simulation of slope stability by the digital elevation model (DEM), site investigations, and monitoring data. Results show that Baoshan Village contains many potential slide surfaces distributed in different areas, three of which have high potential sliding surfaces. The assessment of slope stability analysis can provide a tremendously meaningful reference for disaster mitigation of Baoshan Village.
When can we prioritise environmental flow release without affecting hydropower and water demand satisfaction?
Authors: Sunil Akshay , Singh Riddhi
Published: March 2024

Large multi-purpose reservoirs are required to support socioeconomic development in many parts of the world. However, impoundment of streamflow also negatively impacts instream aquatic ecology. Simultaneously, there are often conflicts between different objectives of multi-purpose reservoirs, such as hydropower generation and water storage for sustaining demands using dry seasons. Thus, releasing environmental flows, while ideal, is often accorded secondary priority unless there are legislative norms in place to facilitate their release. Here, we quantify the compromises between environmental flow maintenance, hydropower generation, and water demand satisfaction across five major multi-purpose reservoirs in India. We investigate these compromises for two type of release priority orders, which are reflected in two versions of a multi-objective decision problem (a) one that prioritizes environmental flow releases over demand satisfaction (PF_MEF) and another that does not (PF_nMEF). Pareto approximate strategies for reservoir operation are identified for each formulation using the Borg multi-objective evolutionary algorithm considering multiple objectives related to annual demand deficits (minimize), hydropower production (maximize), reliability of maintaining environmental flows downstream (maximize), and reliability of non-exceedance of high flows downstream (maximize). In each case, radial basis functions (RBFs) are used to develop flexible release rules as a function of reservoir storage. The resultant Pareto approximate strategies are analyzed to understand when environmental flow prioritization over other releases is practical. In all five projects, hydropower generation exhibits trade-offs with both demand satisfaction and environmental flow reliability. However, the slope and the nature of tradeoffs are governed by other factors such as the storage inflow ratio and the demand-to-inflow ratio at annual time scales. We aim to provide a generalized guideline as to – when prioritizing environmental flow does not impact other objectives of the multi-purpose reservoir project.
Mapping directional sea surface slopes associated with seamounts from SWOT and validation with ICESat-2
Authors: Nilsson Bjarke , Andersen Ole B. , Arildsen Rasmus Lørup
Published: March 2024

Observations from satellite altimeters are essential to mapping the marine gravity field and bathymetry. As most of the ocean basins are yet to be mapped by sonar, obtaining reliable data of sea surface height and sea surface slopes is key to improving our understanding of the marine gravity field and bathymetry. Improvement in altimeter systems has enabled the marine gravity field to be determined to a few mGal, however with conventional satellite altimetry, improvements are challenging.The major challenge is the sampling geometry of conventional satellite altimeters, with along-track (majorly north-south) sea surface slopes being much better determined than across-track slopes (east-west). With the KaRIn instrument on the Surface Water and Ocean Topography (SWOT) satellite, swath-altimetry with 2-dimensional observations of the sea surface height is possible. From these observations, the directional sea surface slopes in both along-track and across-track can be determined. However, determining the resolution and precision with which the sea surface slope is determined, is of fundamental importance for the improvement of the mapping of the marine gravity field.We present directional sea surface slopes associated with a major seamount using SWOT L2 data and with a minor seamount using SWOT pixel-cloud data, demonstrating the quantum leap forward possible with SWOT. With three parallel beams, ICESat-2 is another satellite that can determine the east-west sea surface slope. From observing the difference in sea surface height between beams, we can determine the directional sea surface slopes in north-south and east-west components, with auspicious results. With data from ICESat-2, we aim to validate the SWOT directional sea surface slopes at cross-overs between SWOT and ICESat-2 and determine the relative initial performance.
Data-Driven Modelling and Comparative Analysis of CO2 Exchanges in Dutch Peatlands via Eddy-Covariance: Ground-calibrated bottom-up model vs airborne flux measurements
Authors: Bataille Laurent , Hutjes Ronald , Kruijt Bart , van der Poel Laura , Franssen Wietse , Biermann Jan , Jans Wilma , Ingle Ruchita , Rietman Anne , Buzacott Alexander , van Giersbergen Quint , Nouta Reinder
Published: March 2024

Peat soil degradation in rural areas contributes to 3% of the annual GHG emissions in the Netherlands. In the 2019 climate agreement, the Dutch government set a goal to cut these emissions by 25% by 2030 and initiated a research consortium to achieve this, the Dutch National Research Programme on Greenhouse Gases in Peatlands (NOBV). The NOBV established a GHG monitoring network to map emissions based on the diversity of peat, edaphic conditions, grassland management, and water table management.Eddy-Covariance plays an essential role in this monitoring network. More than 20 sites are part of it, including permanent and mobile EC towers, while an intensive airborne measurement campaign co-occurs above the studied areas. The first offers a high-temporal resolution monitoring of flux, covering a limited spatial landscape diversity; the latter provides a comparative map embracing the whole heterogeneity of the landscape during short timeslots.A data-driven bottom-up model will be implemented. This model will focus on considering site-specific factors and characterizing the heterogeneities of the surroundings through footprint analysis. This approach is a progression from previous efforts that compared annual carbon budgets across various locations based on external data sources, which combined remote sensing and hydrological models and implemented a machine-learning framework to gap-fill time series.Validation of the model includes a comparison with the airborne datasets. Beyond evaluating the quality of the model, the objective is to assess the strengths and limitations of this bottom-up approach when compared to real, independent datasets describing accurately spatial fluctuation of fluxes in heterogeneous landscapes.The insights are essential for future developments, including models that leverage ground network and airborne measurements in the training process for more robust and accurate CO2 Fluxes modelling.
Updated Exposure Estimate for Indonesian Peatland Fire Smoke using Network of Low-cost Purple Air PM2.5 sensors
Authors: Graham Ailish M , McQuaid James B , Smith Thomas E L , Nurrahmawati Hanun , Ayona Devina , Mulawarman Hasyim , Adam Chaidir , Spracklen Dominick V , Rigby Richard , Choiruzzad Shofwan A B
Published: March 2024

Air pollutant emissions from wildfires on Indonesian peatlands lead to poor regional air quality across south-east Asia. Fine particulate matter (PM2.5) emissions are particularly high for peat fires leading to substantial population exposure to PM2.5. Despite this, air quality monitoring is limited in regions close to peat fires meaning the impacts of peatland fires on air quality is poorly understood and it is difficult to evaluate predictions from atmospheric chemistry models. To address this, we deployed a network of low-cost (Purple Air) PM2.5 sensors at 8 locations across Central Kalimantan, where peat fires are frequent. The sensors measured indoor and outdoor PM2.5 concentrations during August to December 2023. During the haze season (September 1st to October 31st), daily mean outdoor concentrations were 120 mg m-3 but peaked at >400 mg m-3. Indoor PM2.5 concentrations were only ~10% lower (mean 110 mg m-3), indicating that is difficult for the population to reduce their exposure to PM2.5 from fires. The reduction in mean PM2.5 concentrations between outdoor and indoor environments was larger in urban locations (-11%) compared with rural locations (-3%), suggesting urban housing may provide better protection from outdoor air pollution. To generate an updated assessment for the population’s exposure to peatland fire PM2.5 we combine the information from monitoring both indoor and outdoor PM2.5 concentrations with modelled ambient (outdoor) PM2.5 concentrations from the WRF-Chem atmospheric chemistry transport model. Our updated exposure assessment accounts for the population’s personal exposure to peatland fire PM2.5 for the first time.