bluuebunny/crossref_metadata_2025 huggingface dataset:
New Insights into the Effect of HCO3-, CO32- and SO42- Ions on the Zeta Potential of Intact Carbonate Rock Sample
Authors: Vinogradov Jan , Atiwurcha Nacha , Vega-Maza David , Derksen Jos
Published: February 2023

Zeta potential is an important interfacial property that controls electrostatic interactions between mineral, water, and non-aqueous phase fluids. These interactions play an important role in defining the wetting state of reservoir rocks and transport of ionic species through porous media. The zeta potential is shown to be an efficient means for a broad range of applications including monitoring of single- and multi-phase flows in subsurface settings, characterization of fracture networks, efficiency of CO2 sequestration, hydrogen underground storage and enhanced oil recovery. It is widely agreed that the zeta potential in carbonate rocks is controlled by the concentration of potential determining ions (PDI), but the understanding of the underlying mechanisms is still limited as there are little experimental data on quantitative characterization of the dependence of the zeta potential on concentration of negative potential determining ions (PDI) such as SO42-, CO32-, HCO3-, especially when their concentration is high and exceeds that of the positive PDIs.In this study, the streaming potential method is used to investigate the zeta potential of natural carbonate rock samples in contact with natural aqueous solutions of low-to-high ionic strength and with varying concentration of sulphate (SO42-) and carbon (C4) related (HCO3-, CO32-) ions. In each set of experiments the total ionic strength was kept constant to eliminate the impact of concentration on the zeta potential so that the increasing/decreasing concentration of negative PDI was adjusted by decreasing/increasing concentration of indifferent Cl- ions. The study probed the concentration of negative PDIs that has never been reported before, with their respective lowest concentration consistent with previously reported equilibrium values, and the highest concentration being equal to the maximum achievable through stripping the tested solutions of Cl-.Our results demonstrate for the first time that magnitude of the negative zeta potential increases linearly with log10 of C4 concentration, however its dependence on the log10 of SO42- concentration is non-linear suggesting varying mechanisms of this PDI’s specific adsorption. Moreover, the results demonstrate that the zeta potential strongly depends on the total ionic strength, interpreted from slopes of the linear regressions for each negative PDI in different background solution. This observation suggests that equilibrium constants of negative PDI specific adsorption may be affected by the total ionic strength. Our findings improve the current understanding of the complex physicochemical processes that take place at calcite-water interface and provide important experimental data for surface complexation modelling of carbonate-brine systems.
Investigating the Near-cloud Aerosol Direct Radiative Effects Under Cloud Organizations of Sugar, Fish, Gravel, and Flowers
Authors: Yang C. Kevin , Chiu J. Christine
Published: February 2023

Near-cloud aerosols have distinct direct radiative effects (DRE) compared to aerosols far from clouds due to aerosol hygroscopic growth and cloud-related processes. Since near-cloud regions cover approximately 20-30% of the globe, DRE from these regions must be understood and better quantified. However, retrieving aerosol properties in the vicinity of clouds is challenging, mainly because the adjacent three-dimensional (3D) cloud radiative effects obscure aerosol scattering signals. In this paper, we will first introduce a new method for retrieving aerosol properties in the vicinity of clouds, capitalizing on machine-learning techniques that allow us to incorporate 3D radiative effects directly. Using this retrieval capability, we will show how DRE varies with cloud organizations such as Sugar, Fish, Gravel, and Flowers, which are commonly observed in the trade-wind regimes. More importantly, we will discuss the implications for near-cloud aerosol DRE under a warmer climate.
First HFC-134a retrievals and analysis of long-term trends from FTIR solar spectra above NDACC network stations: the Jungfraujoch case
Authors: Pardo Cantos Irene , Mahieu Emmanuel
Published: February 2023

Since the discovery of the chlorofluorocarbons (CFCs) implication in stratospheric ozone destruction, the Montreal Protocol (1987) has aimed at controlling the production of CFCs and other ozone depleting substances (ODS) in order to protect and then recover the ozone layer. Consequently, temporary substitutes for CFCs have been developed and produced by the industry. First substitute molecules were hydrochlorofluorocarbons (HCFCs), which have smaller ozone depletion potentials (ODP) than CFCs since their atmospheric lifetimes are shorter. Nevertheless, HCFCs still contain chlorine atoms and hence, also deplete the stratospheric ozone, requiring them to be banned in turn. Thus, chlorine-free molecules, i.e. hydrofluorocarbons (HFCs) such as CH2FCF3 (HFC-134a) were introduced to replace both CFCs and HCFCs. Even if HFCs do not contribute to ozone depletion, they are very powerful greenhouse gases since they have great global warming potentials (GWPs). Consequently, the Kigali amendment (2016) to the Montreal Protocol aimed for their phase-out.The atmospheric concentrations of CFCs have decreased in response to the phase-out and ban of their production by the Montreal Protocol and its subsequent amendments, while the HCFCs burden is now leveling off. In contrast, the atmospheric concentrations of HFCs have increased notably in the last two decades.We present the first retrievals of HFC-134a from Fourier Transform Infra-Red (FTIR) solar spectra obtained from a remote site of the Network for the Detection of Atmospheric Composition Change (NDACC.org): the Jungfraujoch station (Swiss Alps). We discuss of the applicability of our retrieval strategy to other NDACC sites, for future quasi global monitoring from ground-based observations. We further perform first comparisons with other datasets as ACE-FTS satellite observations. 
Mechanical Earth Modelling for Petroleum Reservoir in Western Offshore India: Tensile Failure Study
Authors: Pradhan Sarada Prasad , Sundli Krishna Chandra
Published: February 2023

Quantifying in-situ stress is crucial for predicting drilling-induced tensile fractures, wellbore failures, proper well placement, hydro-fracture treatment optimization and sand production. A comprehensive mechanical earth model incorporating pore pressure, stress state, and rock mechanical properties enable us to study the cause of failure observed in the well. The study is focused on a petroleum reservoir in Western Offshore India. In this study, an attempt is made to estimate in-situ stresses present in the field. Well-log data calibrated with available direct pressure measurements viz. Modular Dynamic Test (MDT) and Leak Off Test (LOT) data are used to predict the pore pressure and minimum horizontal stress. Vertical stress is estimated by extrapolating the density log; for minimum and maximum horizontal stress, the poroelastic approach is adopted. Key rock strength parameters were estimated using standard correlations and regional studies. Wellbore stability analysis was carried out, and the results were calibrated with the actual mud weight used. Natural fractures present in the reservoir are sensitive to stress distribution which in turn is sensitive to changes in pore pressure distribution. Many exploratory and development wells have been drilled in the area, but very few have recorded DSI (Dipole Shear Sonic Image) and FMI (Formation Micro-Scanner Image) logs. With the available log data, the study was carried out to quantify the rock mechanical parameters and the stress magnitudes of the field. The study aims to model the study area's geomechanical aspect for better prediction of drilling-induced challenges, thereby reducing NPT and optimizing drainage.
Preliminary earthquake catalog (2012–2021) of the southern Korean Peninsula by deep learning-based techniques
Authors: Han Jongwon , Seo Keun Joo , Byun Ah-Hyun , Kim Seongryong , Sheen Dong-Hoon , Lee Donghun
Published: February 2023

Earthquake monitoring has been stepped up due to high-density permanent networks in the southern Korean Peninsula, though its relatively low seismicity. With the dramatic increase of data volume, deep learning techniques can be effective ways to process them. In this study, we present a preliminary, but comprehensive earthquake catalog in the southern Korean Peninsula for research purposes by applying a series of deep learning-incorporated methods including for earthquake and phase detection, event discrimination, and focal mechanism determination. We first improved the EQTransformer by re-training it with hybrid local and STEAD datasets to perform earthquake and phase detection for 10-year-long data from 2012 to 2021. Then, the subsequent phase association was carried out using the algorithm based on a Bayesian gaussian mixture model. In the result, 66,855 events were identified and located from 691,077 phase detections. Among them, 27,429 natural earthquakes were separated with a novel CNN model trained using event waveforms and origin time constraints. The natural seismicity suggested various earthquake clusters that constrained by tectonic structures, such as the Okcheon belt and Gyeongsang basin, and showed significantly low rate of occurrence in the Gyeonggi massif. In addition, we developed a CNN model for the determination of focal mechanisms that identify the polarity of initial P-waves in input waveforms, and the application of it resulted in 2,345 reliable solutions. Strike-slip motions were dominant in the inland, while reverse faulting of coastal earthquakes, showing an average P-axis direction of N74E in both areas. Despite the massive volume of data, it took less than a week to perform all of the processes with more cataloged earthquakes than those in the previous one (9,218). The extended earthquake catalog accompanied by focal mechanisms underpins data-driven studies such as tomography, stress field estimation, earthquake hazards assessment, and burial fault mapping.
The effects of the polar rain on the polar wind ion outflow from the nightside ionosphere
Authors: Li Kun
Published: February 2023

The polar wind, consisting of low-energy ions and electrons, is an outflow along the open magnetic field lines from the polar cap ionosphere to the magnetosphere. Previous studies found that both solar radiation and solar wind electromagnetic energy are the two main energy sources for the polar wind. The polar rain, being field-aligned precipitating electrons from the solar wind to the polar cap, may provide additional energies for the polar wind. This scenario is complicated as simulation studies show that polar rain changes the electric potential structures over the polar cap ionosphere. It is unclear how the polar rain affects the polar wind ion outflow. In this study, we show a positive correlation between the polar wind and the polar rain. Meanwhile, the polar wind is generally diminished in regions with strong Earth’s magnetic field, suggesting the B modulates the penetration depth of the polar rain through the magnetic mirror force and thus the energy dissipation of the polar rain. Therefore, the polar rain can be an additional energy source for the polar wind although the polar rain has generally smaller energies and intensities than the particle precipitations in the auroral regions.
Timing and Tempo of Deccan volcanism relative to the KPg extinction revealed by Mercury and Tellurium anomalies
Authors: Adatte Thierry , Regelous Marcel , Khozyem Hassan , Spangenberg Jorge E. , Keller Gerta , Karabeyoglu Uygar , Schoene Blair , Khadri Syed F.R.
Published: February 2023

Mercury (Hg) and more recently tellurium (Te) are indicator of large-scale volcanism in marine sediments and provide new insights into relative timing between biological and environmental changes, mass extinctions and delayed recovery. Several studies evaluated the relationship between Hg anomalies in sediments and LIP activity across mass extinction horizons. The bulk (80%) of Deccan Trap eruptions occurred over a relatively short time interval in magnetic polarity C29r. U-Pb zircon geochronology reveals the onset of this main eruption phase 350 ky before the Cretaceous-Tertiary (KT) mass extinction. Maximum eruption rates occurred before and after the K-Pg extinction, with one such pulse initiating tens of thousands of years prior to both the bolide impact and extinction, suggesting a cause-and-effect relationship.We present a comprehensive high-resolution analysis of Deccan Traps Hg-Te loading, climate change and end-Cretaceous (KPB) mass extinction from a transect, which includes 30 sections deposited in both shallow and deep environments. In all sections, results show that Hg concentrations are more than 2 orders of magnitude greater during the last 100ky of the Maastrichtian up to the early Danian P1a zone (first 380 Ky of the Paleocene). Hg anomalies generally show no correlation with clay or total organic carbon contents, suggesting that the mercury enrichments resulted from higher input of atmospheric Hg species into the marine realm, rather than organic matter scavenging and/or increased run-off. Significant and coeval Hg enrichments are observed in multiples basins characterized by proximal and distal, as well as shallow and deep-water settings, supporting a direct direct fallout from volcanic aerosols. Hg isotope data from Bidart confirm a direct Hg fallout from volcanic aerosols. Te/Th ratios measured in the Goniuk (Turkey), Elles (Tunisia), Gubbio (Italy) and Wadi Nukhul (Egypt) sections show the same trend as Hg/TOC and are consistent with a volcanic origin, albeit a minor extraterrestrial contribution of Hg to the boundary cannot be excluded. Te and Hg are however not correlated with iridium contents in the KPg interval and are consequently not related with impact and maximum eruption rates occurred before and after the K-Pg extinction, with one such pulse initiating tens of thousands of years prior to both the bolide impact and extinction
Sentinel-1 Soil moisture validation with Multiple sources of observations in the mountainous area in Korea
Authors: Cho Seongkeun , Jeong Jaehwan , Choi Minha
Published: February 2023

Soil moisture is a key factor in analyzing the water cycle on the land surface. Active microwave sensor has been widely used for spatially representative soil moisture content regardless of weather conditions. Especially C-band microwave sensors (Scatterometer and Synthetic Aperture Radar) loaded on a satellite were adopted for capturing soil moisture over the vegetated area. However, in heterogeneously or thickly vegetated areas, it is difficult to get accurate soil moisture content with SAR sensor for high spatial resolution (< 1 km). In this study, high-resolution soil moisture content in mountainous areas is estimated and evaluated with in-situ soil moisture observation and a Cosmic-Ray Neutron probe (CRNP) sensor. To evaluate the satellite-based soil moisture product, the SMC Soil Moisture observation site, designed for monitoring soil moisture content, was used. The site has 16 FDR sensors for 10 cm, 20 cm, and 30 cm. At the center of the site, CRNP is operated for measuring spatial soil moisture content. Firstly, the Sentinel-1 backscattering signal, strongly affected by land surface conditions in the mountainous areas, was analyzed. Then, canopy attenuation and the relation between the backscattering signal and the local incidence angle on the mountain were evaluated. Secondly, Sentinel-1 images on the observation site were resampled to 10 m, 50 m, 100 m, and 150 m. Water Cloud Model and change detection method were applied to estimate soil moisture content for the 4 scales. Lastly, estimated soil moisture content was compared with CRNP soil moisture data and ASCAT data on observation sites. Error analysis for each pixel included in ASCAT pixels was conducted to figure out the main obstacles of soil moisture estimation on mountains. With the result of this study, high-resolution soil moisture estimation on the Korean peninsula which mainly consists of the mountainous area would be suggested.Acknowledgment: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2022R1A2C2010266). This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education(2021R1A6A3A01087645)
A USLE and SCS-CN coupled approach for design sediment yield prediction
Authors: Sharma Ishan , Mishra Surendra Kumar , Pandey Ashish , Aragaw Henok Mekonnen , Singh Vijay P
Published: February 2023

Knowledge of sediment yield is essential for predicting and mitigating the impact of natural disasters such as floods and landslides as well as for managing water resources and ecosystems of a region. It has been found that a considerable portion of sediment yield is sometimes generated from extreme rainfall events of high magnitude and intensity compared to that from myriad small rain events. Therefore, it is vital to accurately predict sediment yield resulting from extreme storms of varying durations, especially from data-scarce regions. This study proposes an empirical approach based on the Universal Soil Loss Equation (USLE) and Soil Conservation Service-Curve Number (SCS-CN) methods integrated with a sediment yield model to predict sediment yield resulting from a storm of desired duration (d) and recurrence interval (T). To this end, the potential erosion (A) is empirically related to ‘d’ and ‘T’ and the empirical relation is calibrated and validated on the data of ten sub-watersheds of Ashti catchment, India, involving annual maximum rainfall (observed), runoff (daily observed) and sediment (daily SWAT simulated). The model performance is evaluated using Nash-Sutcliffe Efficiency (NSE), Coefficient of Determination (R2), Percent Bias (PBIAS), Normalized Root Mean Square Error (nRMSE), and visually by scatter plots. The model was calibrated with high NSE, low nRMSE and PBIAS values in all the sub-watersheds (NSE>0.85, PBIAS< ±10% and 0.156< nRMSE <0.216). In validation, the performance was also excellent (0.77≤ NSE ≤0.98 mean value = 0.86, PBIAS ≤ ±20%, and 0.86≤ R2≤ 0.99 mean value = 0.95) in 9 out of 10 sub-watersheds. Additionally, a correlation matrix between catchment physiographic characteristics (terrain slope, stream length and size) and calibrated empirical parameters (‘α’, ‘β’, ‘m’ and ‘n’) was developed, indicating stream length influences these parameters more than size and slope.
Effects of vegetation root on erosion degree under different arrangements of river banks.
Authors: Chiang Yen-Ching , Li Jin-Fu , Chen Su-Chin
Published: February 2023

With environmental protection becoming more and more important in recent years, the suitability of traditional regulation methods in rivers such as bank protection and river cutoff begins to be challenged. The regulation methods combined with ecology have become an important goal in natural rivers nowadays. In this research, a series of flume experiments were conducted to discuss the effect of bank erosion on vegetation roots between bare and vegetated banks.The experimental parameters of flow discharge, water depth,  and channel slope are 0.014 , 9.5 cm, and 0.001, respectively. A kind of vegetation, Vigna radiate, is planted in cultivation boxes for 1 – 2 weeks and then moves into the channel as the vegetated banks. A laser scanner is set up on the flume channel to record the variation of initial and final topography. The results show that the erosion ratios of bare and vegetated banks are 40.24 % and 24.34 %, respectively. The root system of vegetation has a function of anti-erosion on river banks. In addition, we observe the exposed roots formed a protective layer along the flow direction on the bank over a period of time after beginning the experiment. The protective layer by roots helps the river bank resist water erosion and reduce the amount of erosion in the covered area.
Detection of materially coherent eddies in the Bay of Bengal
Authors: Jayan Lijin , Mandayi Jishad , Agarwal Neeraj , Sharma Rashmi , Mathur Manikandan
Published: February 2023

Eddies are prominent features in the ocean and these energetic circulatory motions influence lateral and vertical transport of heat, mass and momentum. Ability of these eddies to coherently transport various scalar species is an important consideration in understanding freshwater transport, locating regions of harmful algal blooms, oxygen deficient zones and potential fishing zones. In this study, we present an implementation of Lagrangian Averaged Vorticity Deviation (LAVD) technique to detect materially coherent eddies from satellite derived sea surface currents in the Bay of Bengal (BoB). We also evaluate the efficacy of a Eulerian method based on sea surface height (SSH) in capturing materially coherent eddies in the BoB. Parameter values for robust detection of eddies are determined by performing a systematic sensitivity analysis in both the methods. Finite time material behaviour of eddies detected using both the methods are evaluated by numerical particle advection experiments. We then focus on material coherence of Sri Lanka Dome (SLD), an annually occurring cyclonic eddy of dynamical relevance in the BoB. SLD characteristics including its spatio-temporal evolution is discussed by analysing ocean surface currents data spanning 27 years from 1993 to 2019.
Developing a SMART flood early warning system for a mountain watershed: experiences from the Lesser Himalayas
Authors: Dixit Sudhanshu , Yasmin Tahmina , Khamis Kieran , Ross Antony , Sen Subir , Sen Debashish , Buytaert Wouter , Hannah David M. , Sen Sumit
Published: February 2023

In the current context of climate change, urban areas in the Himalayas frequently experience flash floods. During high-intensity rainfall events in the catchments, due to hilly terrain and steep slopes, headwater streams cause flash floods and destroy life and property downstream. Increased encroachment along riverbanks and unplanned urban settlements expose financially distressed communities to the elevated risk of floods. This requires developing a reliable warning/alert system to ensure better preparedness for flood hazards and improve disaster resilience. Adequate hydrometeorological monitoring is a key element of such a system to generate knowledge on catchment/watershed characteristics as part of a broader disaster mitigation framework to reduce flood risk. The Bindal river in Dehradun (the capital city of Uttarakhand state in India) lies in the Doon valley on the foothills of the Himalayas, having a significant elevation difference of 450m with an area of 44.4 km2. The downstream settlements of the Bindal river experience flash floods during the monsoon season. Utilizing a SMART approach (developing shared understanding, monitoring, and awareness of the associated risks for preplanning response actions on time), this study aims to leverage and test a low-cost sensor network to provide information of hydrological variability and runoff response in the Bindal catchment. The SMART sensor network consists of 3 LiDAR river water level sensors and 4 tipping-bucket rain gauges at 15-minute intervals. The observed data showcases a substantial variability at both spatial and temporal scales within the small catchment of the Bindal river. The correlation coefficient (p value<0.05) between the rainfall observations at different stations varied from 0.82 to 0.20, with distance between their locations varying from 2.74 to 8.24km. The difference in total monthly rainfall recorded in two rain gauges 8.24 km apart in September is 187 mm. Additionally, the preliminary data suggests urban settlements in the downstream receive heavy rainfall within a short duration, while upper-catchment regions receive low-intensity rainfall for a longer duration. Future work will focus on developing a correlation between rainfall intensity and streamflow to define Intensity-Duration (ID) thresholds for early warning of flash floods. Similar systems in mountain landscapes with long-term rainfall and discharge data can contribute to establishing effective and low-cost flood warning systems for vulnerable riverine communities, particularly in developing countries.
Eustatic and environmental implications of a microgastropod shell bed in the Cenomanian–Turonian boundary interval in the Narmada Basin (India)
Authors: Charthamkudam Prakasan Sooraj , Punekar Jahnavi , Singh Brijesh
Published: February 2023

The Cenomanian–Turonian boundary (CTB; ~94 Ma) marks a period of extreme climate warming, the highest sea-levels of the Phanerozoic, and a turnover in marine microfossils and macroinvertebrates. This boundary interval is marked by black shales that mark a global carbon cycle perturbation and the Oceanic Anoxic Event-2. However, the identification of OAE-2 is complicated by the frequent absence of black shales and/or age diagnostic fossil species, and diagenetic overprinting of δ13C data. This warrants a systematic investigation of other biostratigraphic indicators of the OAE-2 crisis. This study investigates the stratigraphic utility of a microgastropod-dominated shell bed as a key marker within the OAE-2 interval.A regional lensoidal microgastropod-dominated shell bed (2 to 10 cm thick) is observed in the shallow marine carbonate sequence the of Bagh group of sediments (Narmada basin) in the Karondia, Soyla, Jeerabad, and Rampura outcrops near Manawar, India. Previous reports suggest a Turonian age based on ammonite biostratigraphy. We test the hypothesis that the microgastropods indicate biotic stress in shallow marine environments due to OAE-2. The age diagnostic planktic foraminifera are absent. However, low-diversity benthic and planktic foraminifera assemblages with low oxygen-tolerant species confirm biotic stress in Nodular Limestone Formation. Microfacies studies indicate a low-energy supratidal to upper intertidal environment of deposition for the Nodular Limestone Formation, which bears the microgastropod shell bed. The occurrence of microgastropods in association with opportunist planktic foraminifera (e.g., Muricohedbergella, Planoheterohelix) indicate a pioneering palaeocommunity of generalists that colonized new ecospace on the shelf created by the late Cenomanian-early Turonian transgression in the Eastern Narmada Basin. Similar and coeval microgastropod shell beds have been reported from the Tethyan marginal sites of the Western Saharan Atlas of Algeria (Whiteinella archeocretacea zone, CTB interval), Eastern Desert of Egypt (Vascoceras proprium zones, lowermost Turonian) and Upper Benue Trough, Northeastern Nigeria (Turonian). The diachronous occurrence of microgastropod shell beds at various Tethyan marginal sites may be due to a regional offset in the timing of marine incursion. 
Reducing negative impacts of bias adjustment on the distribution tail and extreme climate indicators in MIdAS
Authors: Berg Peter , Bosshard Thomas , Bärring Lars , Södling Johan , Wilcke Renate , Yang Wei , Zimmermann Klaus
Published: February 2023

Bias adjustment of climate models is today normally performed with quantile mapping methods that account for the whole distribution of the parameter. The bulk of the distribution is well described as long as sufficient data records are used (Berg et al., 2012), however, the extreme tails will always suffer from large uncertainties. These uncertainties stem from both the climate model and the reference data set, which prevents a robust and detailed identification of bias in the extreme tail. Empirical quantile mapping methods are therefore prone to overfitting, and may introduce substantial bias when applied outside the calibration period. Commonly, a constant adjustment is applied for values outside the range of the calibration period, but there is room for improvements of the extrapolation method.While working with a climate service for Sweden, a clear offset was identified between data adjusted within and outside the calibration period for an extreme indicator of daily maximum precipitation. This study explores different extrapolation methods for the extreme tail of the distribution in the spline-based empirical quantile mapping method of the MIdAS bias adjustment method (Berg et al., 2022). By limiting the bias adjustment to the first 95% of the distribution, and thereafter applying a constant or a linear fit to the remaining 5% of data in the tail, the offset is strongly reduced and the adjusted extremes become more robust and plausible.Berg, P., Feldmann, H., & Panitz, H. J. (2012). Bias correction of high resolution regional climate model data. Journal of Hydrology, 448, 80-92.Berg, P., Bosshard, T., Yang, W., & Zimmermann, K. (2022). MIdASv0. 2.1–MultI-scale bias AdjuStment. Geoscientific Model Development, 15(15), 6165-6180.
Co-seismic landslide damming in the Indian Himalayas
Authors: Vashistha Akshat , Subramanian Srikrishnan Siva , Das Josodhir
Published: February 2023

In mountainous terrains, coseismic landslide dams are catastrophic geological hazards that induce devastating and cascading effects on humanity. Identification of historical landslide dams is necessary to mitigate the long-term effects it may cause in the future. If not controlled or necessary mitigation measures are not appropriately applied, the landslide dam deposits may have longer implications in generating cascading hazards through geological time. Coseismic landslide dams in the Indian Himalayas are not explored more except for very few studies. Here, we propose a framework to examine the potential for coseismic landslide damming and analyze the possible mitigation strategies to minimize the effects. We use the framework to analyze the potential of coseismic landslide damming in Uttarakhand, India, in the western part of the Himalayas. In addition, to make a coseismic landslide dam susceptibility map, we identified around a dozen landslide dams along major river systems in Uttarakhand which were not mapped or identified earlier. We found that many landslides during the Chamoli 1999 earthquake triggered many dams. While major earthquakes after 1999 did not occur in Uttarakhand, the possibility of coseismic landslide disasters should not be overlooked, and preparedness and mitigation strategies become inevitable to avoid cascading damages by landslide damming. 
Impacts of anthropogenic and non-anthropogenic factors on summertime ozone variation from 2015 to 2020 in the Yangtze River Delta, China
Authors: Li Lin , Li Jingyi , Qin Momei , Xie Xiaodong , Hu Jianlin
Published: February 2023

The variability of ozone (O3) concentration in China has received wide attention since the emission reduction policies were implemented in 2013. At present, it is still a great challenge to clarify the causes of O3 change in the Yangtze River Delta (YRD) region. In this work, we applied the Community Multiscale Air Quality (CMAQ) model to investigate the impacts of precursor emissions (such as non-methane volatile organic compounds (NMVOCs) and nitrogen oxides (NOX)) and meteorological conditions on the summertime maximum daily 8-h average (MDA8) O3 variation in Nanjing, a megacity in YRD between 2015 and 2020. The meteorological contribution was quantified by the difference between the sensitive scenario fixing the anthropogenic emission at 2015 level while remaining the meteorology unchanged in 2020 and baseline scenario in 2015. The impact of anthropogenic emissions was then estimated by the difference between the total change of observed MDA8 O3 and the meteorological contribution. Compared with 2015, the observed MDA8 O3 in Nanjing decreased by 19.1 μg/m3 during August in 2020, with the meteorological conditions and anthropogenic emissions contributing 8.4 μg/m3 (44%) and 10.7 μg/m3 (56%), respectively. The anthropogenic emissions of VOCs and NOX in Nanjing in August 2020 decreased by 7.8% and 11.7%. Temperature, relative humidity (RH) and wind filed are key meteorological parameters affecting the O3 formation. The lower temperature (30.3 ℃ in 2020 compared with 32.4 ℃ in 2015) and higher RH (76.9% in 2020 and 56.9% in 2015) in early August (especially in 4-5) as well as the clean air mass brought by the stronger wind (5.1 m/s in 2020 and 2.5 m/s in 2015) during August 13-14 in 2020 mainly resulted in a drop of O3. The longer hydroxyl radical (OH) chain length and higher ozone production efficiency (OPE) indicate that the reduction of anthropogenic emissions accelerated the NOX cycle and makes O3 more sensitive to NOX. Using the EKMA diagram, we estimated that O3 formation has shifted from VOCs-limited in 2015 to a transition regime jointly controlled by VOCs and NOX in 2020. Our study is consistent with previous ones that in reducing the urban ozone pollution, both the precursor emissions and meteorological conditions should be considered that with the benefit of meteorological conditions, reasonable emission reduction measures could have a positive effect on the reduction of O3 concentration in Nanjing during August in 2015 and 2020.
Characteristics of vegetation according to the micro-climatic conditions of a lava pit on Jeju Island
Authors: Park Eun-Ha , Yang Ju-Eun , Park Minji , Kwak SangEun , Lee Bora , Seol Ara
Published: February 2023

Jeju Island is a volcanic island created by the eruption of a lot of basaltic lava through plume activity. Lava pits come in many shapes and sizes and have unique environmental conditions. This study aimed to examine the vegetation characteristics of various lava pit microclimates of Geomunoreum lava tube system formed 100-300 thousand years ago, and is one of the largest on Jeju Island. Seven plots on Geomunoreum surveyed using the belt transect method, and air temperature and relative humidity were also collected for each plot. The similarity index of the lower area (plot 3) and outside flattening-out areas (plots 6 and 7) were 14.6% and 17.5%. The lower area has the highest mortality and lowest growth rates, and therefore having a simple structure compared to other areas, with no observed changes in dominant species. At the midpoint areas (plots 2 and 4) the dominant species transitioned from Quercus glauca to Acer palmatum and Camellia japonica. The species composition of the shrub and subtree layers remained almostly unchanged. At the higher areas (plots 1 and 5), changes in species composition were frequently observed in all layers. At the outer flattening-out areas (plots 6 and 7), the lowest mortality and highest growth rates were observed, the variety of competing species were high diverse in the tree layer. The daily average temperature of plot 3 (low) and plots 6 and 7 (flattening-out areas) ranged from 4.1℃ to 13.2℃, and the daily average humidity ranged from 1.2% to 39.3%. The simple vegetation structure of the lower area can be attributed to this low temperature and high humidity. The concluding observation is that on the Geomunoreum lava pit, areas where microclimate conditions remain fairly constant, there is no dramatic change in vegetation compared to the perimeter. These characteristics are not always observed on other lava pits on the island.
Hydrodynamic control of sediment-water fluxes: Consistent parameterization and impact in coupled benthic-pelagic models
Authors: Umlauf Lars , Klingbeil Knut , Radtke Hagen , Schwefel Robert , Bruggeman Jorn , Holtermann Peter
Published: February 2023

Benthic oxygen dynamics and the exchange of oxygen and other solutes across the sediment-water interface play a key role for the oxygen budget of many limnic and shallow marine systems. The sediment-water fluxes are largely determined by two factors: sediment biogeochemistry and the thickness of the diffusive boundary layer that is determined by near-bottom turbulence. Here, we present a fully coupled benthic-pelagic modeling system that takes these processes and their interaction into account, focusing especially on the modulation of the sediment-water fluxes by the effects of near-bottom turbulence and stratification. We discuss the special numerical methods required to guarantee positivity and mass conservation across the sediment-water interface in the presence of rapid element transformation, and apply this modeling system to a number of idealized scenarios. Our process-orientedsimulations show that near-bottom turbulence provides a crucial control on the sediment-water fluxes, the oxygen penetration depth, and the re-oxidation of reduced compounds diffusing upward from the deeper benthic layers especially on time scales of a few days, characterizing oceanic tides,internal seiching motions in lakes, and mesoscale atmospheric variability. Our results also show that the response of benthic-pelagic fluxes to rapidchanges in the forcing conditions (e.g., storm events) can only be understood with a fully coupled modeling approach.
High resolution regional climate model points to a wetter UK with widespread afforestation
Authors: Buechel Marcus , Dadson Simon , Slater Louise , Berthou Ségolène , Keat William , Lewis Huw
Published: February 2023

Interest continues to grow in the benefit of afforestation for carbon sequestration, yet the potential consequences of largescale afforestation on terrestrial hydrology are still unknown. Furthermore, it is unclear how large land cover changes may alter the surface-atmosphere hydrological connection, particularly as the climate and hydrological cycle evolve. In this study, we investigate how terrestrial and atmospheric hydrological processes in the UK may alter with increases in woodland across the UK, Ireland, and parts of Western Europe. We use a convection permitting physics-based regional climate model (HadREM3-RA11M) at 2.2 km resolution to simulate and identify the responses of afforestation on hydrology. Afforestation scenarios were generated using existing datasets from regional authorities and previous studies, with tree type determined according to pre-existing landcover. We compare modelled scenarios of widespread afforestation and existing land cover for a future period up to 2080 (with Representative Concentration Pathway 8.5) to assess the consequences of expanded woodland on terrestrial and atmospheric processes within the UK in a much warmer climate. Model results show clear and substantial changes in hydrology in both the atmosphere and land surface with woodland expansion. Soil moisture increases, leading to a commensurate boost to subsurface flows, which is particularly greater in summer months. Although runoff increases throughout the country, there is a proportionally greater increase in the drier south-eastern UK. Evaporation broadly decreases across the country, primarily driven by a reduction in soil evaporation, although this varies seasonally. Precipitation patterns also alter substantially, with increases in the west and slight increases and decreases in the east of the country. These results provide unique insights into how models that couple the land surface with the atmosphere can identify potentially far-reaching consequences of afforestation in temperate regions.
Cluster and MMS simultaneous observations of the Earth’s magnetosheath region in 2017-202
Authors: Munteanu Costel , Teodorescu Eliza , Echim Marius
Published: February 2023

We search for ESA’s Cluster and NASA’s MMS missions’ simultaneous observations of the Earth’s magnetosheath (MSH) region. Visual inspection of Cluster quicklook plots is used to determine Cluster-MSH crossings. Next, MMS quicklook plots are inspected, and the MMS-MSH crossings which overlap in time with the Cluster-MSH intervals from step 1, are catalogued. We find 117 simultaneous crossings in 2017-2021. Our overall goal is to investigate the correlation between the properties of the magnetosheath and the bow shock (BS) characteristics. Thus, for each one of the MSH intervals in our catalogue, we determine the BS characteristics. The Earth’s bow shock can be classified as either quasi-parallel or quasi-perpendicular, depending on the angle between the interplanetary magnetic field (IMF) and bow shock normal direction. We use OMNI data to determine the IMF direction, and we estimate the BS normal direction using two approaches: (1) from magnetic field measurements using minimum variance analysis and (2) from a bow shock model using solar wind data as input. We will present our catalogue of simultaneous Cluster-MMS magnetosheath crossings, and also our estimates for the BS type associated with each crossing.
Contamination of organic raw materials and recycled organic fertilizers with antibiotics
Authors: Albert Sophia , Bloem Elke , Babin Doreen , Smalla Kornelia
Published: February 2023

Since the resources for mineral fertilizers are limited and the energy costs have recently risen considerably, there is an increasing interest in closing nutrient cycles and the recycling of nitrogen and phosphorus in secondary raw materials. Nutrient-rich waste materials can be used directly as a fertilizer or after processing. If other valuable ingredients such as organic carbon are in the product after processing, pollutants can be present as well. In the present work, contamination by antibiotics will be discussed. Antibiotics are used in large quantities to treat bacterial infections in humans but also in animals for food production. Resistant or even multi-resistant strains can occur in feces if antibiotics are regularly used in higher quantities. It was the aim of the study to show which recycled organic fertilizers contain a particularly high amount of antibiotics and how this might affect the relative abundance of resistance genes and mobile genetic elements. Sewage sludge and composted sewage sludge, digestate with animal excrements, residues from food production and processed fertilizers such as ash products or struvite were studied. Exemplary, 14 antibiotics out of three classes were analyzed. Especially fluoroquinolones and tetracyclines are present at higher concentrations in fertilizers of animal origin. In processed fertilizers, the concentrations depend not only on the origin but also on the carbon content, since antibiotics can bind to organic matter.
Towards tomographical MAX DOAS profile retrieval: sensitivity studies
Authors: Pukite Janis , Beirle Steffen , Donner Sebastian , Lauster Bianca , Ripperger-Lukosiunaite Simona , Ziegler Steffen , Wagner Thomas
Published: February 2023

The ground-based Multiple Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurement technique is of high interest to measure local scale pollution events like trace gas plumes above cities or power plants. Besides vertical column densities and especially for the comparison with in-situ measurements and model simulations, vertical profiles of aerosol extinction and trace gas concentrations are retrieved. In this the horizontal extent of the plume is usually neglected in the forward modelling (i.e. horizontally homogeneous distribution is assumed).Here we investigate by sensitivity studies on simulated measurements 1) the systematic errors induced when in fact a horizontally limited plume is measured while neglecting the limited horizontal  plume extent in the retrieval, 2) the capabilities to correct for these errors by a tomographic measurement scheme scanning the same air masses by two instruments, and 3) we provide an outlook to the practical applicability of such a measurement concept. 
Detection of disastrous convective events in the great alpine region and analysis of their sensitivity to the climate change
Authors: Pichelli Emanuela ,   CORDEX-FPSCONV Team
Published: February 2023

An abnormal episode of high rain or snow is classified as heavy precipitation; its extreme intensity and driver mechanisms can vary a lot depending on location and season. The most extreme events can turn into a severe impact at ground (in terms of flood or flash-flood, human casualties and injuries, ecosystem and economy damages and losses).We have implemented a method to detect the most extreme precipitation events trough 10-year long dataset of high-resolution observations and built on a list of the most disastrous ones occurred between 2000 and 2009 within the so called great alpine region (1°–17° East, 40°–50° North).The method is then applied to the models belonging to the coordinated experiment CORDEX-FPS dedicated to convection and the ensemble at the convection permitting  scale is able to represent the 70% of such kind of extreme events. The main drivers of the extreme precipitation are analysed and the factors affecting the model ability in correctly reproducing the unsuccessful cases are also investigated.The same framework has been applied also to the model projections under the RCP8.5 scenario to study the sensitivity of such episodes and of their driving mechanisms to the climate change. The extreme events are projected to increase in frequency especially in the fall season over sub-regions with prevailing orographic forcing, whereas the events related to complex mesoscale interactions are projected to affect larger areas at the end of the century, posing the conditions of increased flood risk.
Various error factors in GNSS-A seafloor geodetic observation
Authors: Nagae Koya , Ishikawa Tadashi , Watanabe Shun-ichi , Nakamura Yuto , Yokota Yusuke
Published: February 2023

Japan Coast Guard (JCG) has been developing seafloor geodetic observation with positioning accuracy at the centimeter level using the Global Navigation Satellite System – Acoustic ranging combination technique (GNSS-A). JCG has deployed a seafloor geodetic observation network called SGO-A along the Japan Trench and the Nankai Trough, where megathrust earthquakes have repeatedly occurred. Up to the present, observations at the SGO-A sites showed the crustal deformation caused by the 2011 Tohoku earthquake (Sato et al., 2011), the subsequent viscoelastic relaxation (Watanabe et al., 2021), the interplate coupling of the Nankai Trough (Yokota et al., 2016) and shallow slow slip events along the Nankai Trough (Yokota & Ishikawa, 2020). Currently, JCG publishes the position time series of the SGO-A sites analyzed by the open-source software GARPOS (Watanabe et al., 2020), based on the empirical Bayesian method.
Recent efforts to improve of the accuracy of GNSS-A seafloor geodetic observation have revealed that there is a wide variety of GNSS-A observation error factors. So far, some error factors have been pointed out, such as the disturbances in the underwater sound speed structure (Yokota et al., 2019) and the influence of the observation plan (Nakamura et al., 2021). In addition, data reanalysis and water tank experiments have clarified that waveform reading errors in acoustic ranging, device characteristics and angle dependence of the acoustic sonar have a great influence on seafloor station positioning analysis. In this presentation, we discuss the error factors in such GNSS-A observations while comparing with the error factors in GNSS observations. For some of the error factors, we introduce our efforts to improve the observation accuracy. 