bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinearity of the cloud response postpones climate penalty of mitigating air pollution in polluted regions
Authors: Jia Hailing , Quaas Johannes , Hasekamp Otto
Published: March 2024

Aerosol–cloud interactions contribute substantially to uncertainties in anthropogenic forcing, in which the sensitivity of cloud droplet number concentration (Nd) to aerosol plays a central role. Here we use satellite observations to show that the aerosol–Nd relation (in log–log space) is not linear as commonly assumed. Instead, the Nd sensitivity decreases at large aerosol concentrations due to the transition from aerosol-limited to updraft-limited regime, making the widely used linear method problematic. The similar nonlinear behavior is also observed in weekly cycles; specifically, polluted conditions exhibit a reduced amplitude of weekly cycles in Nd compared to clean conditions with similar aerosol perturbations.  A sigmoidal transition is shown to adequately fit the data. When using this revised relationship, the additional warming that arises from air pollution mitigation is delayed by two to three decades in heavily polluted locations, compared to the linear relationship. This cloud-mediated climate penalty will manifest markedly starting around 2025 in China and 2050 in India after applying the strongest air quality policy, underlining the urgency of mitigating greenhouse gas emissions.
Tracking 13C into soil organic matter through the mycorrhizal fungal pathway under nutrient addition
Authors: Barker Kaydee S. , Meehan Matthew L. , Johnson David , Bardgett Richard D. , Robinson Clare H.
Published: March 2024

Arbuscular mycorrhizal (AM) fungi are ubiquitous plant symbionts that mediate soil organic matter (SOM) formation through nutrient exchange and the accumulation of their own biomass and necromass. Recent studies suggest that microbial necromass, including fungal necromass, may account for upwards of half of SOM carbon, but the specific contribution of AM necromass remains unknown. Additionally, how land management impacts AM-mediated SOM is not well understood, especially in grasslands where AM fungi are prevalent and play a key role in regulating plant diversity and ecosystem function. We grew Lolium perenne with four treatments: (1) an inoculation of AM spore-rich sandy soil, (2) an application of nitrogen-phosphorus-potassium (NPK) fertilizer, (3) a combination of spore-rich soil and NPK, and (4) a control. We isotopically labelled plants with 13C-CO2 before incubating the roots and AM hyphae in place, and are measuring 13C in SOM, plant and microbial pools, and released CO2 at multiple timepoints over 6 months to track C through decomposition. Our preliminary results show that both 13C and 13C-CO2 respiration were lower for fertilizer treatments compared to control and inoculation-only treatments during the first month of incubation. This demonstrates that even a small one-time NPK application may influence subsequent decomposition of root and AM tissues at the end of the growing season. The lower amounts of 13C respiration may be due to differences in plant carbon to nitrogen ratios, leading to higher microbial carbon use efficiency, or NPK addition may have inhibited the growth of AM hyphae, leading to decreased available 13C in the soil. These hypotheses will be investigated further with additional measurements as outlined above. By using stable isotope tracing into biomarkers, SOM pools, and soil respiration, our study will shed light on the contribution of AM and associated root necromass to SOM carbon and provide needed insight for conscious grassland management.
 Dissecting the spatio-temporal variability of soil hydraulic properties in an agricultural eroded area
Authors: Brunetti Giuseppe , Kodešová Radka , Fér Miroslav , Nikodem Antonín , Klement Aleš , Šimůnek Jiří
Published: March 2024

The combined effect of anthropogenic and climatic stressors deeply influences the hydrological behavior of agricultural areas, especially on hillslopes. Tillage induces an abrupt change in the soil's hydraulic functioning, which can be dynamically recovered in time due to natural consolidation, alternation of wetting and drying cycles, and other biophysical factors. Heavy rainfall can accelerate the recovery process, but also induce erosion events in tilled soils, further exacerbating the spatial variability of the topsoil hydraulic properties. To better understand the mechanisms driving the spatio-temporal variability of soil hydraulic properties in agricultural areas, we combine the modified hydrological model HYDRUS with transient soil moisture observations from two hillslopes in the Czech Republic exposed to tillage and erosion. In particular, the Bayesian inference is used to calibrate two alternative HYDRUS implementations at five different locations along the hillslopes. The first model assumes static soil hydraulic properties, while the second simulates their dynamic change induced by tillage and natural consolidation (due to rainfall). The Watanabe-Akaike Information Criterion (WAIC) is used to compare the two models by considering not only the fitting accuracy, but also the predictive uncertainty. The results show that both models can reproduce soil moisture observations satisfactorily at different depths and locations. While the dynamic model exhibits slightly better fitting, this is compensated by larger predictive uncertainty compared to the static model. This is confirmed by the WAIC values, which are similar for the two models. An in-depth analysis indicates that the dynamic recovery of soil hydraulic properties happens during the first few rainfall events (confirming what was observed in other studies) and suggests that higher resolution measurements are needed to better estimate recovery factors. Finally, the spatial variability of the estimated soil hydraulic parameters hints at a possible role of overland flow fluxes along the hillslope as a heterogeneity-generating factor. 
Detecting volcanic lightning with different methods: a comparison
Authors: Hort Matthias , Geisler Andre , Heck Fransizska , Behnke Sonja , Edens Herald , Iguchi Masato
Published: March 2024

The origin of volcanic lightning is still a matter of intense research because it may complement other monitoring techniques in detecting volcanic eruptions at remote or not well monitored volcanoes. Various methods have been used to detect electrical discharges over the last decades and here we compare four different methods for the detection of electrical discharges which were operated in late 2019 at Sakurajima volcano. The electrical activity was observed by an electric field mill (EFM, which measures the static electrical field at 10 S/s (samples/second)), a thunderstorm detector from Biral (BTD, also measures the static electrical field at 100 S/s), as well as a lightning mapping array station (LMA, measuring VHF electromagnetic radiation) and a fast antenna FA (time constant τ = 10-4 s⁻¹, 180MS/s). We developed special algorithms to identify electrical discharges in the EFM and BTD data sets because those were the most continuous data sets available to us. From a period of high volcanic activity during which also data from the other instruments were available, we then picked several eruptions characterized by different types of electrical discharges. We analyzed the number of discharges detected by each instrument as well as how well the amplitudes (electrical field changes) are resolved by the different instruments. We find good correlations of detected signal strength between the FA and EFM data, the correlation between these data and the BTD is especially for larger events not as perfect. In order to analyze this problem, we use the FA measurements to downsample and synthetically reconstruct the BTD data set, showing deviations for larger amplitudes as well. Overall, the instruments show good agreement on detecting electrical discharges within volcanic eruptions with differences on the detection of „assumable weaker“ signals. We highlight the advantages and disadvantages of the different techniques in terms of detecting electrical discharges during volcanic eruptions. We finish discussing how the different instruments can be used to determine electric field changes as well as further investigate the type of electrical discharges detected.
Understanding driving mechanisms of induced seismicity at the Balmatt geothermal site
Authors: Wassing Brecht , Broothaers Matsen , Buijze Loes , Candela Thibault , Pogacnik Justin
Published: March 2024

Ambitions to accelerate development of geothermal energy production require development of new geothermal targets. One such target for production of geothermal energy in the Netherlands, Germany and Belgium is the Dinantian fractured carbonates play. The Balmatt geothermal project in Mol (Belgium) is the first deep geothermal project realized in northern Belgium. The project targets the fractured carbonate sequence of the Carboniferous Limestone Group. The site comprises a geothermal plant with three wells drilled to a maximum depth of 4200 m. The production well targets the permeable damage zone of the regional Beringen Fault, whereas the injection well targets a reservoir section at significant distance from the mapped regional fault structures. Equipped with a dedicated monitoring network and having been operated as a research facility, with varying injection rates and volumes, the Balmatt geothermal project provides a unique dataset to analyze the relationship between doublet operations and induced seismicity. In this study, we used seismicity data in combination with operational data on flow rates, injection and production temperatures and well head pressures, to analyze the relationship between operations and seismic activity. Using a coupled thermo-hydro-mechanical model, we quantify the contribution of the physical processes of pressure diffusion, thermoelasticity, poroelasticity and (a)seismic stress transfer to fault loading and induced seismicity. This way we aim to further our understanding of the potential  mechanisms driving seismicity in the fractured carbonates at the Balmatt site and in fractured carbonates in general. A better mechanistic understanding of the relationships between operations and seismicity can help managing seismic risks of geothermal operations in these fractured reservoirs. These insights are crucial for designing operations in a way that minimizes risks of induced seismicity in the Dinantian carbonates and to define the operational window at the site.
Marine heatwave inhibition of gelatinous zooplankton carbon flux into the deep ocean
Authors: Ličer Matjaž , Perharič Bailey Črtomir Ernest , Vodopivec Martin , Tinta Tinkara
Published: March 2024

Once gelatinous zooplankton (GZ) organisms die, they begin to sink. During the sinking process they decay, with decay rates strongly dependent on ambient ocean temperature - warmer temperatures accelerate mass decay rates in the upper water column during the presence of a marine heatwave, leading to reduced GZ carbon flux into the deep ocean. We leverage this temperature dependence of the decay rates to quantify marine heatwave (MHW) related inhibition of vertical GZ mass fluxes out of the euphotic zone (at 200 m depth). We use established methodologies for MHW detection and quantification to isolate some of the strongest MHW events in the northwest Mediterranean in the past 20 years, specifically June 2003, July 2006 and July 2019 events. We present a new Lagrangian tracking class CarbonDrift for the OpenDrift environment, which couples mass decay and organism sinking rates while allowing for horizontal advection during sinking. We use this Lagrangian model for vertical tracking of the sinking organisms and compute the fraction of the sinking organism mass reaching the bottom of the euphotic zone under i) climatological temperature field and ii) during the three mentioned MHWs. The difference between climatological and MHW simulations allows  quantification of the impact of MHW on the vertical carbon flux out of the euphotic zone. We show that during each of these marine heatwaves, carbon export out of the euphotic zone (at 200 m) decreases by 2 - 6 % in comparison to exports in climatological conditions. The accumulated effect of this inhibition proportionally diminishes Mediterranean's capacity to act as a deep ocean carbon sink.
Controls on recent pyrite formation in aquatic systems and its relevance for environmental processes
Authors: Peiffer Stefan
Published: March 2024

The formation of pyrite has been extensively studied because of its abundance in many anoxic environments such as marine and river sediments, groundwater aquifers, and peat lands, and hence its importance in both iron and sulfur cycling. It forms over a wide pH interval, ranging from acidic to alkaline. It is generally regarded that sulfide reacting with iron-containing minerals forms metastable iron sulfide minerals before eventually transforming into pyrite in the presence of different sulfur.In this contribution, I will discuss the importance of sulfidation of ferric (oxy)hydroxides (FeOOH), i.e. the reaction between aqueous sulfide and the surface of FeOOH, to stimulate pyrite formation and compare this process with other pathways and kinetics of pyrite formation described in the literature. Sulfidation of FeOOH initially leads to formation of surface bound FeS-species and its transformation to pyrite is controlled by either the availability of FeOOH or the supply rate of sulfide. These kinetic constraints define the environments were rapid pyrite formation occurs to be suboxic, rich in FeOOH and shaped by cryptic sulfur cycling. Under these conditions, highly reactive pyrite precursor species are forming that also affect trace metal cycling.
Seabed substrate mapping based on machine learning using MBES data
Authors: Seo Jeong Min , Son Sanghun , Bae Jaegu , Lee Doi , Park So Ryeon , Kim Jinsoo
Published: March 2024

For mapping of seabed substrate, it is essential to extract and analyze seabed substrate characteristics from measured data such as bathymetry and backscatter.The number of studies have been conducted on seabed substrate classification based on backscatter data obtained from side-scan-sonar, single-beam-echo-sounder, multi-beam-echo-sounder (MBES).These studies presented limitation of low accuracy by mapping of seabed substrate through statistical methods or principal components analysis.The purpose of this study is mapping of seabed substrate using machine learning methods like random forest (RF), support vector machine, and k-nearest neighbor and MBES-based variables.MBES-based variables were built total 23 variables from bathymetry, backscatter, and backscatter-based GLCM statistical methods.Seabed substrate classification schemes were defined 4 classification scheme according to the ratio of gravel, mud, and sand.In the case of RF model and case 4 classification scheme, the F1 score showed the highest accuracy at 82.0%.Through this study, machine learning and MBES-based variables were used to confirm the possibility of high-accuracy mapping of seabed substrate, and it is believed that it can be sued to mapping of seabed substrate in other regions.
 Using thermal tracer tests and numerical models to evaluate the layered flow characteristic in a coastal aquifer system 
Authors: Hsu An-Yi , Ni Chuen-Fa , Hsu Chia-Yu , Chang Yu-Huan
Published: March 2024

 With the increasing economic development in coastal areas, the problem of coastal degradation has emerged. To facilitate subsequent planning of water resources management, it is essential to determine the coastal aquifer's dynamic exchange with ocean. In this research, our objective is to integrate innovative experiments and modeling techniques to assess the heat and water exchanges in the coastal aquifer of the Taoyuan Tableland in northwestern Taiwan. Specific hydraulic and heat tracer tests are conducted at this location to obtain the flow and heat transfer characteristics of the layered flow. In subsequent steps, we employed the MODFLOW and MT3DMS numerical model to simulate the influence of interactions between freshwater and seawater on the temperature field of the coastal aquifer. The calibration of the model is based on the groundwater levels and the temperature acquired from monitoring wells which installed near the coastline at the TAICOAST observation station. The experimental results show that the thermal responses from the active heat tracer test can match with the core sample and calculate the groundwater flux toward the sea. Significant thermal responses are observed vertically in the observation well near the heating well, ranging from the water level to a depth of 12 m, with BW08 being the observation well showing the maximum thermal response. The simulation of numerical model aligns well with the observed water levels and temperature in wells. The simulation provides a three dimensional depiction of the groundwater flow direction, which was used to calculate the velocity of groundwater flow and estimates thermal conductivity at this site. The results reveal the dynamic impacts of tidal variations on the coastal aquifer with high spatial resolution provides the valuable insights into understanding the groundwater discharge in the coastal aquifer system. 
Young trees climate sensitivity above the forestline: the case study of Pinus nigra upward shift in Central Apennines (Italy) 
Authors: Tonelli Enrico , Vitali Alessandro , Piermattei Alma , Urbinati Carlo
Published: March 2024

In the context of ecological research, tree-ring analysis often deals with short time series (< 30 years). Their crossdating and averaging can be difficult but crucial to use such data for ecological modelling, multivariate statistics, and climate-growth analysis. Several studies were conducted in the Central Apennines (Italy) on recent encroachment of European black pine (Pinus nigra J.F. Arnold) on treeless areas above the current forestline. Growth of young trees is mainly controlled by endogenous or microclimatic factors making usual dendrochronology methods less applicable and crossdating very difficult or even impossible. The potential ecological information deriving from tree-ring growth in short series is therefore limited by this methodological bias. The aim of this study is to test suitable methods for optimizing the use of short ring series for further analytical use. A dataset of 734 tree-ring series of young European black pines (mean cambial age 15 years) growing at high altitude in 8 sites was used in this analysis. At each site tree-ring series were divided in two groups based on inter-series correlation: the crossdated or selected series (SEL), and non-crossdated or rejected ones (REJ). The following dendrochronological parameters were calculated for SEL and REJ series: mean tree-ring width, mean sensitivity, Gini coefficient, first order autocorrelation, inter-series correlation, and Gleichläufigkeit (GLK). Two methods of pointer years analysis were tested in order to detect years with synchronous growth: i) Normalization in a moving Window (NW) and ii) the RElative growth change method (RE). The two methods were applied to the raw series varying the standard thresholds, in order to detect synchronous growth-years in SEL and REJ group. A sensitivity analysis was included to assess how the threshold choice in the analysis could affect the results obtained. The term “common” was used to indicate years with similar tree growth response. Differences in the detected number of common years within SEL and REJ were obtained using different time windows with the RE and NW methods. The 47 % of all series were classified as SEL, showing more common years than the REJ series. However, a similar result occurred considering all the series together without SEL/REJ discrimination. In general, a significant occurrence of common years could be a tool to select series to be averaged for a site mean chronology. These are preliminary but encouraging results contributing to a more efficient use of the ecological information provided by short time series from young trees.
Multivariate validation at multistation of distributed watershed hydrological modeling based on multisource data on Chinese Loess Plateau
Authors: Liu Peiling , Liu Dengfeng , Zheng Xudong , Hu Yun , Ming Guanghui , Gao Man
Published: March 2024

Hydrological simulation is an important method of understanding hydrological processes. Earlier hydrological simulation calibration and validation were mainly based on flow observations at hydrological stations, and the multisource observations prompted the hydrological simulation of the basin to move from a single flow validation to a multivariate validation of evaporation-soil water-runoff. In this study, the Jinghe River Basin of China is taken as the study area, and the hydrological processes are simulated and analyzed based on the SWAT distributed hydrological model. Firstly, a single-station, single-variable calibration is carried out based on the flow observation data at Zhangjiashan Hydrological Station, and then the multivariate validation of actual evaporation, soil water and runoff is carried out using multisource data, and four simulation evaluation indexes, namely, R2, NSE, PBIAS, and KGE, are used to assess the performance of the hydrological model in the Jinghe River Basin. The four evaluation indexes of the SWAT model constructed in the Jinghe River Basin in the calibration period are 0.78, 0.67, -2.1%, and 0.75, respectively, and the evaluation values in the validation period are 0.77, 0.64, 18.2%, and 0.72, respectively. The results satisfy the requirements, which indicates that the model has good applicability. In the regional calibration based on the consideration of spatial variability, the stations of Qingyang, Yangjiaping, and Zhangjiazhan have R2, NSE, and KGE above 0.57 and PBIAS within 25% in the calibration period, and the higher the simulation accuracy in the downstream. In the validation period, the R2, NSE, and KGE are above 0.50 and PBIAS is within 25%, except the station of Qingyang, where the result of the validation period is better than that of the calibration period. After the regional calibration, the monthly runoff simulation of Zhangjiashan station has been improved. In the multivariate validation of evaporation-soil water-runoff, the validation result of the runoff is the best, followed by actual evaporation, and soil water content is a little worse. In the two datasets of actual evaporation, TEDAC has better verification performance at Yangjiaping station and Zhangjiashan station, and GLDAS has better verification performance at Qingyang station. After further calibration of parameters, the evaluation results of each hydrological variable have been improved. The multivariate verification based on multisource data improved the hydrological simulation of river basin scale.
Mass Balance of Greenland and Antarctic Ice Sheets since the 1970s
Authors: Kaitheri Athul , Otosaka Ines , Shepherd Andrew
Published: March 2024

Ice sheets in Antarctica and Greenland have continued to undergo rapid changes since the 1970s causing a significant rise in global mean sea level. The Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) community has produced reconciled estimates of ice sheet mass changes for both ice sheets from the 1970s till 2021 by combining more than 50 independent mass balance estimates produced from varied satellite observations. Ice sheet mass changes are driven by competing processes due to their interaction with the atmosphere (surface mass balance) and ocean (ice dynamics). Here, we present an updated IMBIE assessment and partition mass trends into their surface mass balance (SMB) and ice dynamics components. This new assessment shows that Antarctica and Greenland contributed 29.3 mm to the global mean sea level between 1979 and 2021. While in Antarctica, almost all ice losses were driven by ice dynamical imbalance, we find that 60 % of Greenland’s ice losses were caused by increased ice discharge with reduced SMB accounting for the remainder. This exercise reveals the different drivers of Antarctica and Greenland mass changes and highlights their high interannual variability. Finally, we are aiming at producing reconciled regional ice sheet mass balance estimates for the main drainage basins of Antarctica and Greenland for the first time and will be presenting preliminary results for some of the key regions of the ice sheets that have been undergoing rapid changes. Partitioning mass trends and producing regional assessments will contribute to a better understanding of the remaining differences between the different satellite geodesy techniques employed within IMBIE and will provide a key dataset for both the Earth Observation and ice sheet modelling communities. 
Integrating Multi-Sensor Remote Sensing Data for Comprehensive spatio-temporal WildfireAssessment In Campania Provinces – Italy
Authors: Dadkhah Hanieh , Rana Divyeshkumar , Ghaderpour Ebrahim , Mazzanti Paolo
Published: March 2024

Wildfires present substantial threats to ecosystems and human settlements which increase the importance of monitoring for timely detection and assessment. This study was performed on the Campania provinces—Salerno, Avellino, Benevento, Caserta, and Napoli in Italy—employing a multi-sensor remote sensing approach to elevate wildfire analysis. The first objective is identifying fire patches through Moderate Resolution Imaging Spectroradiometer (MODIS) data from 2001 to 2020. Although, generating Difference Normalized Burn Ratio (DNBR) and Difference Normalized Difference Vegetation Index (DNDVI) maps from Sentinel-2 images. Integration of MODIS and Sentinel-2 outcomes enhances pinpointing fire-affected areas. Subsequently, Incorporating Landsat 9 images for Land Surface Temperature (LST) and Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) for precipitation trends in five provinces from 2001 to 2020 in Hotspot Polygons generated via First Order Contiguity edges corners algorithm. Pearson correlation coefficients between burnt area, LST, and precipitation are computed. A high correlation coefficient was observed between the mentioned parameters. Wildfire analysis reveals peak burnt areas in 2001, 2007, and 2017 in Avellino and Salerno Province. Change detection maps illustrate significant land cover changes from Forest to Savannas and Shrubland to grasslands in 2001. Avellino province reveals a decreasing trend in Grassland and an increase in Savannas, as the same as observations in Salerno Province. This study considers the analysis of wildfires, connecting burnt areas, climate variables, and land cover changes across the Campania provinces.Keywords: Wildfire, Fire and Vegetation Indices, Land Cover Changes, Climate Change
Investigating SST's Role in Seasonal Climate Variations: A WRF Model Analysis in the Tropical Zone, Thailand
Authors: Lerdrittipong Surapong , Zhong Jian , Widmann Martin , Bradley Christopher , Dixon Simon
Published: March 2024

The phenomenon of climate change, with its unique alterations in global temperatures and weather trends, presents a mounting obstacle for accurate weather prediction and climate simulation. This study uses the Weather Research and Forecasting (WRF) model to investigate the impact of variations of Sea Surface Temperature (SST) during the rainy season (17 May to 31 Oct 2016). The research aims to quantify the effect of changes in SST (0.5 to 2.0 degrees Celsius) in a climate-sensitive period. Utilising model configured for Thailand's specific geographic and climatic conditions, the study integrates SST data derived from satellite measurements and observations assess temperature, precipitation, and extreme weather events. Our results indicate the pronounced sensitivity of the WRF model to SST variations, with notable discrepancies in predicting rainfall patterns and temperature anomalies. These findings emphasise that SST is a critical factor in climate modelling and the need for accurate SST input in forecasting models, especially in the context of climate change. The study contributes to a better understanding of the WRF model's capabilities and limitations in simulating seasonal climate variations in tropical regions. It may also stress the importance of the governments to engage in effective water and irrigation management strategies, including improved drainage systems and adaptive agricultural practices, to mitigate climate change impacts like flooding and drought. Further research is recommended for other seasons and extended periods for a deeper understanding of the WRF model's performance against evolving climate dynamics.
The role of a multiple intertidal barred (MITB) system in dissipating extreme storm wave energy
Authors: Biausque Melanie , Guisado-Pintado Emilia , Grotolli Eduardo , Jackson Derek , Cooper Andrew
Published: March 2024

First described by King and Williams in 1949, multiple intertidal barred (MITB) features are characterised by a succession of intertidal sandbars, comprising a complex system subject to variable hydrodynamics. Relatively stable under macrotidal conditions and low to moderate wave energy, MITB systems can however, display cross-shore migrations and morphological changes under energetic and extreme events. Storm Barra occurred in December 2021, and crossed the east coast of Northern Ireland. It was the second highest energetic storm to have occurred there in the last 25 years, with waves reaching a maximum significant wave height (Hs) of 5.5m for a peak period (Tp) of 10s and, from a southeasterly direction on the 7th December. To examine the morphological impact on Dundrum Bay and its MITB system, DGPS surveys were conducted, before and after storm Barre, at two adjacent sites, Murlough and Ballykinler beaches, on the 6th and 9th of December respectively. Topographic beach surveys showed distinct alongshore variability at both sites. Despite onshore waves, the Ballykinler site (eastern side of the bay) presented linear post-storm Barra profiles due to a complete flattening of the bar crests and sediment in-filling within the runnels. In contrast, the western end of the bay displayed an elevation of the beach profiles, with the central zone a more transitional area associated with onshore bars’ migrations to no significant changes, eastward. Additionally, nearshore wave modelling (SWAN), including adjustments for surge, was conducted to better understand the wave dissipation patterns and local interactions with sandbars’ morphology. Preliminary wave model results show a significant role of the bars during the event. At the peak of the storm, which corresponded to a falling tide period, the maximum wave dissipation was focussed on the offshore-most bar, just outside the intertidal area and thus limiting impacts on the beach and nearshore MITB system. The following rising tide period however, coupled with decreasing wave height and energy, corresponded with much less intense energy dissipation at the site. During the final phases of the storm, maximum values of wave energy dissipation concentrated closer to the shore and were primarily induced by the MITB system in the intertidal beach area. It therefore appears that the offshore-most bar of the MITB features plays a significant role dissipating extreme events energy and limiting morphological changes, while the other bars are more effective during less energetic conditions and at low tide. SWAN simulations help explain the relatively low coastal impact detected at both Ballykinler and Murlough beaches from storm Barra, although further investigation of sediment transport patterns and (antecedent) storm chronologies throughout the winter 2020/2021 season are still required to fully understand the alongshore variability observed. 
Modeling the Oslofjord bottom oxygen regime interdecadal changes affected by increased waste water discharge in 1970s
Authors: Berezina Anfisa , Yakushev Evgeniy , Staalstrøm Andre , Frigstad Helene
Published: March 2024

Oxygen regime in the vicinity of the sediment-water interface (SWI) was studied with a coupled benthic-pelagic model 2DBP (Yakushev et al., 2020), that considers biogeochemical processes occurring in the water column and the sediments in the same model domain. C-N-P-Si-O-S-Mn-Fe biogeochemical model BROM describes in detail the processes of organic matter mineralization in oxygen-depleted conditions that are vitally important for assessing biogeochemical impacts (i.e., denitrification, metal reduction, sulfate reduction). This allows us to predict changes in redox conditions at the bottom as a function of seasonality (organic matter production and destruction, vertical mixing), anthropogenic (eutrophication), and climatic (temperature and mixing ) factors.This model was applied to the Western Oslo Fjord subjected to an intensive organic waste discharge in the 1960s-1970s. In this period, it was documented the disappearance of shrimps in the bottom layer and increased primary production in the surface layer.This work aimed to reconstruct the Oslo Fjord SWI redox conditions in the past decadal period (1930-2023). It was numerically demonstrated the interconnection between an amount of supplying with waste water organic matter and oxygen depletion processes in the bottom layer. It was shown that in the 1970s there was a shift from normoxic to anoxic conditions. It was also estimated the period of the system restoration to normoxic conditions after the improvement of the wastewater plant in the 1980s. This model can be used for analyzing the consequences of future changes under different scenarios of nutrient discharges to the Fjord.
Characterization of the isotopic signature in methane from several biogenicsources in the central Amazon
Authors: Botía Santiago , Komiya Shujiro , Jones Sam P. , Chanca Ingrid , Horna Viviana , Dajti Gisela , Adnew Getachew A. , Bulthuis Sipko , Schöngart Jochen , Fernandez Piedade Maria Teresa , Wittmann Florian , Marra Daniel Magnabosco , Rothe Michael , Mossen Heiko , Jordan Armin , Röckmann Thomas , Lavric Jost , Sierra Carlos , Trumbore Susan , van Asperen Hella
Published: March 2024

The decreasing global trend in 𝛿13𝐶 − 𝐶𝐻4 suggests that rising biogenic sources of methane are a plausible explanation for the current methane atmospheric growth rate. Furthermore, tropical wetlands represent one of the largest sources of uncertainty in the global methane budget and the Amazon basin plays a crucial role in this context as approximately 20% of its area is annually flooded. However, the availability of methane isotopic composition data for tropical wetlands is scarce, undermining our understanding of these tropical sources.
In this study, we present results from two sampling campaigns during the dry season, one in September 2019 and the other in August 2022. During each campaign, we collected air samples at different locations within the area around the Amazon Tall Tower Observatory (ATTO), such as in a black-water seasonally flooded forest (i.e. igapó), in an upland swampy valley (i.e. baixio), at the Uatumã black-water river and on the 80-m tower located on the upland terra-firme forest at the ATTO site. Air samples were collected with pressurized glass flasks and pre-evacuated vials and were analyzed for the isotopic composition of methane (𝛿13𝐶 and 𝛿𝐷 ) with gas source isotope ratio mass spectrometer. We estimated isotopic source signatures of CH4 emissions from the four different sites using the intercept of an orthogonal fit in a Keeling plot.

Relative to the Amazon atmospheric background value of -59 ‰ per mill (Beck et al., 2012), our isotopic source signatures are more depleted in 𝛿13𝐶 ranging from -60 ‰ to -68 ‰, which confirms -as expected- a strong wetland-related biogenic source. Within this range, methane source signatures from areas near the Uatumã river (-68 ‰) and a periodically flooded valley (representing small streams of the region) have more depleted signatures (- 66 ‰). Using this range of source 𝛿13𝐶 signatures we explore the possibility of identifying different biogenic sources at the Tower based on continuous measurements (in-situ) of

𝛿13𝐶 − 𝐶𝐻4 and a Lagrangian atmospheric transport model to obtain the isotopic background (i.e. the isotopic signature of the air masses before entering the continent). Our results contribute valuable insights into the methane isotopic signature for different ecosystem types in central Amazonia, which could serve as a reference for measurement-based source attribution studies as well as a based on measurements and also for atmospheric transport modeling estimates.
Fine characterization of wind drag force in shallow lakes based on the wind-wave-flow mutual feedback model
Authors: Ang Gao , Wu Shiqiang , Wu Xiufeng , Dai Jiangyu , Wang Fangfang
Published: March 2024

Water environment pollution and water ecological degradation are the common problems in lake. As the dynamic basis of lake system, lake hydrodynamics has a decisive influence on lake water environment and water ecology. The numerical simulation is an important means to study the characteristics of lake hydrodynamics, water environment and water ecology. For numerical simulation of lakes driven by wind, the drag force of airflow on water is usually represented by wind drag coefficient ( Cd ). Cd reflects the momentum transfer efficiency between water and airflow, and is closely related to the characteristics of wind，waves，flow and their mutual feedback mode, and is the most critical parameter to determine whether the numerical simulation results are reasonable. However, the expression methods of wind drag coefficient widely used at present are mostly proposed based on the ocean. The characteristics of ocean wind, wave, flow and their mutual feedback mode are less affected by the blowing range and water depth. Cd is mainly restricted by wind speed ( u10 ) without considering the influence of the blowing range ( F ) and water depth( d ), which has poor adaptability in lakes.In this study, theoretical analysis, wind tunnel experiment, in-situ monitoring and numerical simulation were used to propose a model of wind-water interaction in finite water area considering the wind-wave-flow mutual feedback model. Two dimensionless numbers, u10/(gF)0.5and u10F/νw, which can be used to describe the comprehensive strength of wind-wave and wind-flow interaction in finite water area were constructed. A new expression of wind stress coefficient considering wind speed, blow distance and water depth is proposed (expression (1) ), which improves the limitation of the traditional expression considering wind speed only, overcomes the limitation of its application in limited blow distance and water depth, and maintains the overall consistency with the existing expression. When the wind speed is greater than 5m/s, the wind stress coefficient is positively correlated with u10 and F, and negatively correlated with d，the sensitivity of the three factors to the Cd is 0.92, 0.22 and 0.14, respectively. The results of the three dimensional hydrodynamic mathematical model of Lake Tai show that the simulation results of the wind stress coefficient considering the influence of three factors are more consistent with the measured results.
Modeling microbial functional trait-environment interactions at the continental scale
Authors: Shek Katherine , Stegen James , Roebuck Alan , Goldman Amy , Borton Mikayla , Wrighton Kelly , Wymore Adam
Published: March 2024

Inferring linkages between microbial metabolism and dissolved organic matter (DOM) across environmental gradients is a promising avenue to improve biogeochemical predictions at large spatial scales. Despite decades of metagenomic studies identifying microbial functional trait-environment patterns at small spatial scales, general patterns at continental or global scales that may improve large-scale models remain unresolved. Recent influx of multi-omics datasets that represent diverse environmental conditions has enabled scalable analyses linking microbial metabolic niche breadths with key environmental processes, such as carbon and nutrient transformations.Here, we leveraged publicly available microbial metagenome assembled genomes (MAGs) derived from the Worldwide Hydrobiogeochemistry Observation Network for Dynamic River Systems (WHONDRS) data paired with metabolomic (FTICR-MS) and sediment chemistry data to link microbial metabolic potential with organic chemistry. We annotated 1,384 MAGs representing 65 sites using the R tool microTrait, which categorizes functional traits under the YAS (growth yield-resource acquisition-stress tolerance) framework. Following Hutchinsonian niche theory, we modeled microbial trait combinations as n-dimensional hypervolumes and observed trait-DOM patterns at the continental scale, showing microbial functional tradeoffs along gradients of organic carbon. We expect that at the continental scale, microbial trait profiles will be distinct across climatic regions, and that niche breadth (i.e. the size of individual hypervolumes in trait space) will correlate with DOM/metabolite diversity. The results of this work will distill generalizable patterns of microbe-DOM availability and diversity at large spatial scales, thus identifying information to improve current biogeochemical models.
A machine learning approach to meteor light curve analysis
Authors: Mandl Lucas , Christou Apostolous , Windisch Andreas
Published: March 2024

In this work we conduct a thorough examination of utilizing machine learning and computervision techniques for classifying meteors based on their characteristics. The focus of the re-search is the analysis of light curves emitted by meteors as they pass through the Earth’s atmo-sphere, including aspects such as luminosity, duration, and shape. Through extracting featuresfrom these light curves and comparing them to established meteors orbits, valuable informa-tion about the meteor’s origin and chemical composition is sought to be obtained. A significantcontribution of the thesis is the development of methods for classifying meteors by extractingfeatures from the light curve shape through the usage of unsupervised classification algorithms.This approach allows for the automatic classification of meteors into various groups based ontheir properties. Data for the research is collected by a three-camera setup at the Armagh observatory,comprising one medium-angle camera andtwo wide-angle cameras. This setup enables the capturing of detailed images of meteor lightcurves, as well as various other observations such as coordinate and angular data. The researchalso involves the use of machine learning algorithms for data reduction and classification tasks.By applying these techniques to the data collected from the camera setup, the identification ofparent objects based on chemical composition and meteor path is facilitated, along with theacquisition of other valuable information about the meteors.
Impact of Non-Exhaust Emission on Ambient Particulate Matter Concentration using a Coupled Atmospheric Chemistry –CFD Model
Authors: Park Seon-Young , Kim Myeong-Gyun , Song Hyo-Jong , Kim Jae-Jin , Choi Wonsik , Lee Sanghyun , Lee DaeGyun , Choi Jinyoung , Kim Minjoong J.
Published: March 2024

Vehicular emissions are major sources of gaseous and particulate matter pollutants in urban atmospheres. Stringent environmental regulations on vehicular emissions have been consistently implemented, leading to a substantial decrease in exhaust emissions. In contrast, non-exhaust emissions are increasing with the growing share of electric vehicles. Non-exhaust particulate matter emissions account for approximately 90% of total vehicular emissions. However, standardized guidelines for non-exhaust emissions have not been established, largely due to the challenges in estimating ambient concentrations from non-exhaust particulate matter sources. In this study, we performed a particulate matter simulation to investigate the quantitative impact of non-exhaust emissions in Seoul, using a coupled atmospheric chemistry–CFD model (CFD-Chem). We evaluated the model using various emission factors and determined the most accurate emission factor by comparing it with observed PM concentrations at the pedestrian level. Our simulated PM concentrations follow the diurnal variation of traffic volume, indicating a significant contribution of non-vehicular emissions to PM concentration at ground level. We observed that the impact of non-exhaust sources on pedestrians is higher in alleys than on main streets. Our results suggest that precise simulations are essential for establishing accurate and standardized guidelines for non-exhaust emissions.
Thermal management of urban groundwater resources - climate change, thermal potentials and opportunities
Authors: Epting Jannis
Published: March 2024

In urban areas, increased thermal use of the subsurface, including infrastructure development (e.g., tunnels and underground car parks) and adaptation strategies (e.g., more frequent thermal use of aquifers for "cooling" purposes or increased implementation of the sponge city concept), associated with global warming will inevitably increase urban groundwater temperatures. Likewise, anthropogenic adaptation strategies could have a greater impact than climate change itself.In scope of the presentation strategies for the thermal management of urban groundwater resources in northwestern Switzerland are presented by discussing climate change, thermal potentials, and opportunities for adaptation measures. In particular, there are opportunities related to unused anthropogenic waste heat, especially in the subsurface of urban areas, and the energy potential that could be tapped through suitable construction measures.
River capture frequency and magnitudes are regulated by rock erodibility
Authors: Val Pedro
Published: March 2024

River captures reroute river networks and generate transient pulses of erosion. Their frequency, size, and spatial distribution are also important drivers of freshwater biodiversity. How tectonic, climatic, or autogenic processes influence the frequency-magnitude and spatial distribution of river capture events are unexplored gaps in landscape evolution research with cross-disciplinary implications. Using numerical modeling of landscape evolution in Landlab, I apply the simplest form of the stream power equation to explore the sensitivity of river captures to the exhumation of rocks with higher resistance to erosion (i.e. a lower erodibility parameter – K). The exhumation of heterogenous rock types in a slowly eroding landscape allows for a positive feedback loop to evolve until some drainage basins completely shrink while others expand. In these conditions, the exhumation of a resistant rock intersects river systems with differing incision capacities, thus creating differential relief across drainage divides and initiating divide migration. The continuous drainage area loss enhances drainage divide migration and increases the probability of river captures. For the same background erosion rate, doubling the areal extent of the exhumed resistant rock nearly triples the probability of large river captures and quadruples the size of the largest river capture of the model run. Lastly, the mode of drainage area exchange (i.e. divide migration or river capture) is itself sensitive to the degree of base-level perturbation caused by the exhumation of a resistant rock. In tectonically inactive settings with low erosion rates, the complex spatial distribution of rocks can thus create spatially variable frequency-magnitude distributions of river captures. These preliminary findings reveal an exciting avenue for exploring the origins and sensitivity of river captures to autogenic controls and its consequences for sedimentary fluxes and biogeography.