bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of missing third-law standard entropy of apatites using the optimized Volume-based Thermodynamics
Authors: Puzio Bartosz , Manecki Maciej
Published: February 2023

The standard absolute entropies of many minerals and mineral-based inorganic materials are unknown, thereby precluding a complete insight into their thermodynamic stability. This includes many apatites. The Apatite supergroup is one of the largest groups of minerals. Consequently, they are an incomparable testing ground for finding regularities in the variation of their thermodynamic function of state, e.g., standard entropy (S°). In the early 2000’s Jenkins and Glasser [1] showed that the formula unit volume alone, Vm, can be used to estimate the standard entropy for any inorganic compound.It was recently indicated that in terms of their thermodynamic properties, the apatite supergroup splits into distinct subgroups (populations) [2]. These subgroups are formed by Me10(AO4)6X2 with the same Me2+ cations (e.g., Pb2+, Cd2+, Ca2+, Ba2+, Sr2+) and tetrahedral AO43- anions (e.g., A=P, As, V), but with different anions at the X position (e.g., F-, Cl-, Br-, I-, OH-). We found strong linear relationships between S° of apatites and their Vm observed within these subgroups. A system of linear relationships (calibrated with existing experimental data) indicating high positive correlations within selected subgroups of apatites is presented in Fig. 1.Fig. 1 Standard entropy (S°) vs. formula unit volume (Vm)for selected apatite subgroups. Errors bars are within the marker.Table 1. Selected estimated standard entropies (S°) and calculated formation entropies (ΔS°f, el)of iodine apatites.
Apatite

Estimated S° (J/mol·K)

ΔS°f, el (J/mol·K)

Ca10(PO4)6I2

840.7

-2412.8

Sr10(PO4)6I2

1117.2

-2264.2

Pb10(PO4)6I2

1201.1

-2271.4

Ca10(AsO4)6I2

1016.1

-2205.0

Pb10(AsO4)6I2

1364.5

-2075.5

Pb10(VO4)6I2

1359.6

-2040.0

 Using the new estimated with high accuracy S° values, it is possible to calculate the Gibbs energy of formation and plot stability fields for apatites for which this has not been possible so far. Financial support for the research was provided to B.P. by the Polish National Science Centre (NCN) grant No. 2017/27/N/ST10/00776.References:[1] Jenkins, H. D. B., & Glasser, L. (2003). Standard absolute entropy, values from volume or density. 1. inorganic materials. Inorganic Chemistry, 42(26), 8702-8708.[2] Puzio, B., & Manecki, M. (2022). The prediction method for standard enthalpies of apatites using the molar volume, lattice energy, and linear correlations from existing experimental data. Contributions to Mineralogy and Petrology, 177(11), 1-34.[3] Wang, J. (2015). Incorporation of iodine into apatite structure: a crystal chemistry approach using Artificial Neural Network. Frontiers in Earth Science, 3, 20. 
Betting on CDR under uncertain climate sensitivity is bad climate policy
Authors: Merikanto Joonas , Schaber Theresa , Partanen Antti-Ilari , Ekholm Tommi
Published: February 2023

Climate change mitigation strategies consistent with the Paris Agreement’s temperature targets rely heavily on future carbon dioxide removal (CDR). Although such strategies have drawn considerable critique for long, e.g., that they are ‘betting on negative emissions’, the risks from this betting have not been quantified nor addressed properly. We use a lightweight integrated assessment model SCORE to explore possible scenarios using CDR for limiting global warming to 1.5 °C by 2100. Particularly, we quantify the impacts of relying on CDR when accounting for 1) possible under- and overestimation of the cost, potential, and availability (feasibility) of future CDR and 2) the compound effect with uncertainty in climate sensitivity.All scenario results unquestionably show that aggressive near-term mitigation is required for limiting warming to 1.5 °C by 2100 for all levels of climate sensitivity, but that some amount of CDR is likely required in the future even if climate sensitivity turns out to be extremely low. If uncertainty in climate sensitivity is disregarded, initial assumptions on the CDR feasibility have only minor effects on the total cumulative mitigation cost. However, taking the uncertainty in climate sensitivity into account changes this conclusion. Wrong assumptions on CDR feasibility can, surprisingly, even lead to lower costs under extreme realizations of climate sensitivity, especially in scenarios where CDR feasibility is underestimated. Assuming low feasibility for CDR eliminates the possibility of sky-rocketing costs associated with overestimating CDR feasibility in combination with a high climate sensitivity. Therefore, a prudent climate policy should assume a low feasibility of CDR to reduce the risk of leaving runaway mitigation costs to future generations.
Influence of GIA uncertainty on climate applications from satellite gravimetry
Authors: Schawohl Lennart , Eicker Annette , Bagge Meike , Dobslaw Henryk
Published: February 2023

Global coupled climate models are important for predicting future climate conditions. Due to sometimes large and often systematic model uncertainties, it is crucial to evaluate the outcome of model experiments against independent observations. Changes in the distribution and availability of terrestrial water storage (TWS), which can be measured by the satellite gravimetry missions GRACE and GRACE-FO, represent an important part of the climate system. However, the use of satellite gravity data for the evaluation of coupled climate models has only very recently become feasible. Challenges arise, e.g., from the still rather short time series of satellite data and from signal separation issues related to GRACE/-FO observing all mass change including non-water related variations such as glacial isostatic adjustment. Apart from climate model uncertainties, these challenges might be the reason for a disagreement between the direction of linear water storage trends of models and observations in several regions of the world, one of them located in Eastern Canada.
This presentation will highlight the latest results achieved from our ongoing research on climate model evaluation based on the analysis of an ensemble of models from the Coupled Model Intercomparison Project Phase 6 (CMIP6). We will focus on long-term wetting and drying conditions in TWS. Using an ensemble of 52 GIA models that differ in the applied ice history, solid Earth rheology, and numerical code, this presentation will discuss how GIA modeling uncertainty does influence (i) the determination of water storage trends from GRACE/FO data, and (ii) the (dis-)agreement between drying/wetting trends in satellite gravimetry and CMIP6 climate models. We will show that the apparent disagreement between observations and models in highly GIA-affected regions in North America crucially depend on the particular model chosen for reducing the GIA effect from the GRACE satellite data.
Estimating Optimal Sampling Locations of Surface Soil Moisture at Different Scales Using Various Methods and comparing them for a Lower Himalayan Watershed Region
Authors: Sharma Sahil , Swami Deepak , Dubey Amit
Published: February 2023

To compute optimal sampling locations for a lower Himalayan watershed various methods were used. The methods were compared at various scales: watershed scale, landform scale and seasonal scale. The methods compared for the evolution of optimal sampling strategy are statistical sampling, geostatistical sampling, stratified sampling, bootstrap methods and random combination method. To examine the methods, field experiments were conducted in a sampling domain of 425 km2 to study the patterns. At the watershed scale total number of 24 locations were evaluated which were distributed into 12 agricultural, 6 forest and 6 grassland landforms. To study the seasonal patterns comparison for the Rabi and Kharif seasons was done. The results indicated that the random combination method provides a simplified and efficient sampling strategy compared to the other methods. Further the random combination method has an inherent advantage of requiring very minimal input information whereas, the statistical and stratified sampling strategy requires data that has to be independent and normally distributed. The geostatistical methods requires a semi variogram model to get the necessary results. To obtain the results at the same level of error the random combination method gives lesser number of sampling locations required. Additionally the computational efficiency of the random combination method can be increased generating smaller groups of samples for the optimality estimation.  
The Changing Role of Stratospheric Ozone and Greenhouse Gasses in Modifying the Southern Ocean Carbon Sink
Authors: Jarnikova Tereza , Le Quéré Corinne , Rumbold Steven , Jones Colin
Published: February 2023

As the largest oceanic sink of anthropogenic CO2, the Southern Ocean (SO) plays a key role for climate and climate change, absorbing between 5 and 10 percent of the global CO2 emissions from human activities each year. Factors influencing the efficiency of the Southern Ocean CO2 sink include, for example, the rate and level of change of CO2 in the atmosphere and the associated changes in climate, including warming and winds. In particular, winds in the Southern Ocean have been observed to increase in the past 50 years, with this increase linked both to the change of stratospheric ozone and to the observed increase in greenhouse gasses. Here, we use a set of model simulations with the UKESM1 model run from 1950 to the end of the 21st century, we explore the relative contribution of changing greenhouse gases and ozone recovery in driving the evolution of the Southern Ocean carbon sink. Our runs encompass three sets of forcing: one with no ozone, one with ozone but no ozone recovery, and one with best estimated ozone recovery. This set therefore bookends possible evolution of ozone this century and thus the response of the ocean carbon state. Our results demonstrate the critical role of changes in wind distribution in the likely evolution of the SO carbon sink over the course of the 21st century.  
Frequency domain electromagnetic methods for coastal archaeology – a new(ish) approach for the detection of ancient settlements
Authors: Lazar Michael , Basson Uri
Published: February 2023

As sea levels rose since the end of Last Glacial Maximum (LGM) ancient coastal communities were often forced to abandon their settlements and move inland. Today, many of these abandoned sites are covered by sand or lay in shallow water. Examining these can shed light on past coastal communities as well as settlement patterns in ancient times. Archaeological excavation along the coast is particularly tricky and often sporadic in nature. Thus, high‐resolution shallow geophysical methods, which have become a standard in archaeological studies since they provide a noninvasive way of imaging the subsurface before an excavation, would seem like a perfect solution. However, most methods are limited in their ability to work near the shoreline – the transitional zone between classical land-based methods and standard marine ones. Ground penetrating radar (GPR), for example, is greatly affected by moisture and salinity and is therefore limited in its ability to work in areas saturated with seawater. Seismic reflection is time consuming to overcome issues of poor vertical and spatial resolution and sensitive to urban noise, while magnetics would provide poor results for sand covered sandstone. Other techniques, such as electrical resistivity tomography (ERT) have been shown to work in coastal areas and in shallow water. However, this method can be slow, as it involves setting up complex arrays for each cross section measured. This study will present the frequency domain electromagnetic (FDEM) method, which has the potential to overcome these problems and can bridge the gap in knowledge by measuring in the nearshore environment. The ease of use and quick scanning capability means that large areas can be covered in a relatively short time. There are no electrodes or loops to set up. Since it measures swaths, results are obtained in map-view and not cross-section, with little interpolation. Different frequencies penetrate to different depths (lower frequencies corresponding to deeper penetration). Therefore, the result is a series of frequency maps corresponding to the integration of all subsurface data in a specific sampled volume (i.e. down to the frequency-related depths), providing important information on shallow subsurface properties. The use of multiple frequencies allows for the resolving of internal structures within the depth range. Overall, the FDEM method has proven to be a valuable tool for studying coastal archaeology, and it is likely to continue to play an important role in the field in the coming years. Its ability to detect buried objects and structures and to study the geomorphology of submerged landscapes makes it an essential tool for researchers working in this field.
Assessing the indirect impacts of hydro-geological hazards on Italian firms: a nation-wide assessment
Authors: Clò Stefano , Segoni Samuele
Published: February 2023

Italy is a country seriously affected by landslides and floods: these hydro-geological hazards persistently cause fatalities and severe economic losses, but to date little is known on the indirect effects that such hazards exert on the local and national economy.In this nation-wide study, the indirect effects of hydro-geological phenomena on Italian firms are assessed by coupling some indicators of the performance of Italian firms, and a dataset of flood and landslide events.Econometric indicators were defined starting from data provided by organizations such as INPS, ISTAT, CERVED, Tax Registry and Bank of Italy. A geodatabase providing the timing and location of harmful hydro-geological events was compiled by an automated web datamining procedure based on a semantic algorithm scanning internet news. These datasets, with a spatial detail at the municipality level, cover the period from 2010 to 2020 and a statistical analysis was carried out to assess to which extent hydro-geological disasters affected the competitiveness of local economies.The results showed that firms located in municipalities hit by a relevant event face on average a 4.8% increase in the probability of exiting the market with respect to non-impaired firms. Moreover, surviving firms seem to be slightly affected by natural disasters, in particular on the revenue side (-3.5%) and, to a lesser extent, on employment (-1.7%). We also explored the heterogeneity of these effects, discovering that indirect impacts seem more relevant for micro and small businesses, for those active in services and those located in rural and suburban areas.
Assessment of energy production potential from ocean currents along the Brazil coastline taking into account climate change
Authors: Soares Anderson , Falcão Djalma , Toste Raquel , Landau Luiz , Assad Luiz
Published: February 2023

The increasing electricity demand, coupled with the global need to reduce greenhouse gases, has made renewable energies an attractive solution to the problem. The oceans offer good alternatives for diversification and expansion of the energy matrix, among the possibilities for energy production is that one comes from ocean currents. Therefore, this work aims to evaluate the harnessing energy from ocean currents on the Brazilian coast based on the results of the global circulation model used in CMIP5, the Brazilian Earth System Model (BESM). Due to low temporal and spatial resolution, BESM results were downscaled using ROMS. In order to evaluate the effects of climate change on hydrokinetic production in the ocean, the simulation must represent the current climate conditions and the future condition,  based on the historical scenario and RCP4.5 respectively. For this purpose, these results were used as lateral boundary conditions and surface forcing into a two-way nested model composed of a donor and two receiver grids, with 1/5° and 1/15° of horizontal resolution, respectively. The highest resolution grids embrace the regions with the highest hydrokinetic potential on the southeastern and northern coasts, where the Brazilian current or North Brazilian current predominates. In addition to spatial and temporal variability, the synergy between ocean current as a source of electric power supply and others sources from the Brazilian electrical matrix will be discussed.
Anticorrelation of density and magnetic field in a fast magnetosonic mode: The case of surface waves in an inhomogeneous magnetosphere
Authors: Archer Martin , Southwood David , Hartinger Michael
Published: February 2023

Magnetohydrodynamic (MHD) wave theory states that fast magnetosonic waves should have correlated fluctuations in the compressional magnetic field and the plasma density / pressure. Anticorrelation, on the other hand relates either to the slow magnetosonic or mirror modes. These classic results are often used as a diagnostic in waves observed by spacecraft throughout the heliosphere. However, it is important to recognise that they are derived under the assumption of a homogeneous background plasma. Planetary magnetospheres are, in contrast, highly inhomogeneous. When allowing for a non-uniform background, the linearised MHD equations for density and pressure perturbations include terms due to the intrinsic compression associated with the wave as well as advection of plasma parcels with different background values. We argue that these two effects can compete and result in anticorrelation between the density and magnetic field, particularly when the scale of the inhomogeneity is shorter than that of the wave. We demonstrate examples of this anticorrelation applied to fast-mode magnetopause surface waves in both analytic MHD theory and a global MHD simulation. Finally, methods which identify and allow for these effects in satellite observations are discussed.
Possible causes of model biases in simulating Tropical-Arctic teleconnections in CMIP
Authors: Feng Xiaofang
Published: February 2023

The central role of tropical sea surface temperature (SST) variability in modulating Northern Hemisphere (NH) extratropical climate has long been known. However, the prevailing pathways of teleconnections in observations and the ability of climate models to replicate these observed linkages remain elusive. Here, we apply maximum covariance analysis between atmospheric circulation and tropical SST to reveal two co-existing tropical-extratropical teleconnections albeit with distinctive spatiotemporal characteristics. The first mode, resembling the Pacific-North American (PNA) pattern, favors a Tropical-Arctic in-phase (warm-Pacific-warm-Arctic) teleconnection in boreal spring and winter. The second mode, predominant in summer and autumn, is manifested as an elongated Rossby-wave train emanating from the tropical eastern Pacific that features an out-of-phase relationship (cold-Pacific-warm-Arctic) between tropical Pacific SST and temperature variability over the Arctic. This Pacific-Arctic teleconnection (PARC) mode partially explains the observed summertime warming around the Arctic. The reliability of climate models to replicate these leading teleconnections is of primary interest in this study to improve decadal prediction on regional climate. While climate models participating in CMIP6 appear to successfully simulate the PNA mode and its temporal characteristics, the majority of models’ skill in reproducing the PARC mode is obstructed by apparent biases in simulating low-frequency SST and rainfall variability over the tropical eastern Pacific and the summer climatological mean flow over the North Pacific. Considering the contribution of the PARC mode in shaping low frequency climate variations over the recent decades from the tropics to the Arctic, improving models’ capability to capture the PARC mode is essential to reduce uncertainties associated with decadal prediction and climate change projection over the NH.
Radiocarbon signatures of carbon phases exported by swiss rivers in the Anthropocene
Authors: Rhyner Timo , Bröder Lisa , White Margot , Mittelbach Benedict , Storck Florian , Passera Lucas , Haghipour Negar , Eglinton Timothy
Published: February 2023

Lateral carbon mobilization processes are particularly prone to anthropogenic perturbations due to human intervention of the land surface as well as aquatic corridors yet remain poorly constrained despite their importance as a key component of the C-cycle. A major source of this uncertainty involves processes modulating the sources and fate of carbon along the freshwater aquatic continuum. This study examines the radiocarbon (14C) signatures of particulate and dissolved organic carbon (POC, DOC, respectively) and dissolved inorganic carbon (DIC) transported by Swiss rivers with a view to assessing controls on the origin and cycling of carbon within corresponding watersheds. Twenty-one rivers were selected that span a range of watershed properties and are monitored by the National Long-Term Surveillance of Swiss Rivers (NADUF) program, enabling radiocarbon data to be interpreted within a broader hydrological and geochemical context.  Samples were collected during high-flow conditions in summer 2021, a year of extreme rain events. Average discharge of our sample set (n=21) was 299.76 +/- 513.87 m3/s, while the annual average discharge of all stations was 184.90 ± 264.92 m3/s. The range of D14C values of POC was -158‰ to - 446‰ (n = 21), while corresponding ranges of  D14C values for DOC and DIC were - 43‰ to - 377‰ and - 40‰ to - 301‰, respectively, indicating the presence of pre-aged carbon in all three pools. Hydrological properties such as discharge, runoff and precipitation did not appear as major significant controlling factors. Except for DI14C where annual average runoff of the past decade showed a significant negative correlation. Instead, based on Multivariate Regression Analysis, “alpine” variables such as mean basin elevation, slope, and barren areas were negatively correlated with D14C values of all three D14C-phases, while rivers draining lower elevation terrain, where agricultural land-use is more extensive were associated with higher D14C values in -the organic carbon pools (POC, DOC). Repeated sampling under different hydrological conditions and associated 14C (and 13C) measurements are being used to provide additional insights into the controls on the amount and nature of carbon exported by Swiss rivers, the interconnectivity between different carbon pools within the corresponding drainage basins and ecoregions, as well as to predict long-term trends in the context of changing climate and anthropogenic forcing.
Boreal Spring Southern Hemisphere Climate Mode and Global Monsoon
Authors: Srivastava Shikhar , Chakraborty Arindam , Murtugudde Raghu
Published: February 2023

The global climatic pattern is governed by the dominant mode of variability in the tropics and the extratropic and their interaction. The extratropical atmosphere is much more vigorous than the tropics owing to sharp meridional temperature gradients in the mid-latitude. Especially on the decadal timescales, large signals are seen over the extratropical region than in the tropics. Here, we propose that during boreal spring, the second leading mode of climate variability in the Southern Hemisphere, has a decadal pattern. This mode is independent of the Southern Annular Mode (SAM), which represents the most dominant mode of climate variability in the Southern Hemisphere. The boreal spring climate of the Southern Hemisphere interacts with the tropics and significantly impacts the global climate, which is reflected in the global Monsoon rainfall. During the positive phase of the decadal mode, the global Monsoon rainfall is coherently suppressed. We propose a new finding highlighting that the Southern Hemisphere's extratropical forcing can significantly impact the tropical Pacific through subtropical pathways on the decadal to multidecadal timescale. The impact of such decadal climate variability is enormous and global and can add a new paradigm to the pursuit of improving decadal predictions of the global climate.
Impact of accurate representation of Land Use/Land Cover over the National Capital Region (NCR) Delhi in simulating Monsoon Weather
Authors: Chalakkal Jerin Benny , Mohan Manju
Published: February 2023

As cities around the world are growing at a rapid pace, the need to understand their impact on the regional to local climate has become more crucial.  Urban settlements are more affected by extreme weather than rural areas. Localised circulation patterns, the topography of the region and micro-scale systems induced by Land-Use Land-Cover (LULC) can modify regional flows to produce unique patterns in the urban region. National Capital Region (NCR) - Delhi, the second biggest urban settlement globally, reported an almost ~20 fold increase in urban and built-up areas in past decades. NCR urbanisation during the past few decades caused a corresponding increase up to 3–5 and 2–4 K in values of LST and T2m, respectively, while a decrease in the magnitude of surface winds up to 2 m s−1 was noted. The LULC plays a crucial role in meteorological models because they determine the crustal properties that interfere with the exchange of energy, moisture, and momentum between the land surface and the atmosphere. This study attempts to assess the impact of legitimate present-state LULC based on AWiFS in the mesoscale model for simulating monsoon weather over NCR Delhi. The newly implemented AWiFS LULC precisely distinguishes the default MODIS classification used in the model framework. Overall, the AWiFS-based simulations showed an improved performance in predicting the study period during the monsoon.
Voluntary spring monitoring to make invisible groundwater visible
Authors: Retike Inga , Terasmaa Jaanus , Koit Oliver , Bikše Jānis , Demidko Jekaterina , Hunt Marlen , Kukela Agnese
Published: February 2023

Groundwater accounts for nearly 99% of all liquid freshwater on Earth. Not only does groundwater provide almost half of the global drinking water supply and ensures the well-being of humans and sustain dependent ecosystems (rivers, lakes, and wetlands), it is an essential aspect in climate change mitigation too. Despite the exceptional importance of groundwater in social, economic, and environmental processes, it remains poorly understood, mismanaged, and often neglected. In order to increase global awareness of groundwater protection, the theme for World Water Day 2022 was “Groundwater: Making the invisible visible” with the culminating event - the first UN-Water Summit on Groundwater held in Paris on 7-8 December. Data collection and sharing on groundwater were among the key actions highlighted during the Summit because “we cannot manage what we do not measure”.One of the ways to make groundwater visible is to demystify the underground resources beneath our feet through citizen science. Many volunteer water monitoring programs have generated valuable data sets around the world. Data collection by volunteers is cost- and time effective, supports local communities by raising awareness of groundwater protection, and boosts outdoor tourism. Moreover, such campaigns provide information on water bodies that would otherwise remain unmonitored and, if carefully designed, can be used by national water managers and even support decision-making.Here we present a joint Estonian-Latvian web-based application for the volunteer monitoring of springs launched in February 2021 (accessible by allikad.info and avoti.info). The web-based map application aims to collect new information on already known springs and locate new ones by providing clear guidelines on how to carry out proper spring monitoring. More than 200 users have already joined the application and approximately 600 new springs have been added to the database. Together, 1132 new observations have been made and 2930 images of springs have been added. This valuable information source has been recently recognized by national water managing authorities and used to improve the transboundary groundwater monitoring network between Estonia and Latvia. We will present how citizen science can improve groundwater management, as well as our success stories and lessons learned. The study benefits from Iceland, Liechtenstein and Norway through the EEA and Norway Grants Fund for Regional Cooperation project No.2018-1-0137 “EU-WATERRES: EU-integrated management system of cross-border groundwater resources and anthropogenic hazards”  and Interreg Estonia-Latvia cooperation program project “WaterAct”.
Gas sampling and monitoring during Drilling the Ivrea-Verbano zonE (DIVE)
Authors: Dutoit Hugo , Dominique Jessy , Greenwood Andrew , Hetényi György , Masci Lorella , Truche Laurent , Wiersberg Thomas
Published: February 2023

The ICDP project "Drilling the Ivrea Verbano zonE (DIVE)" explores the Ivrea Verbano Zone in the Southern Alps of Italy, the probably most complete pre-Permian lower crust–upper mantle transition worldwide, by deep scientific drilling. A first borehole has been completed near the city of Ornavasso in mid-December 2022, reaching a final depth of 578.5 m, with excellent drill core recovery (100%). The drilling was accompanied by various scientific experiments, including the continuous extraction, measurement and sampling of gases from the circulating drilling fluid (On-Line Gas Analysis, OLGA). The gas phase was continuously measured with two gas mass spectrometers (MiniRuedi © and Pfeiffer Omnistar ©) for Ar, H2, He, N2, O2, CH4 and CO2, a gas chromatograph for hydrocarbons (CH4, C2H6, C3H8 and i/n C4H10), and a radon detector for 222Rn. Off-line samples were taken for laboratory analysis on hydrogen and noble gas isotopes to better characterize the origin of the gases including possible artificial hydrogen from the drilling process.Initial results show a correlation between formation gases in drilling mud and the drilled lithology. In addition to the unavoidable input of atmospheric gases in drilling mud, the most non-atmospheric gases extracted from drilling mud are hydrogen (up to ~1.2 vol.-%) and methane (up to ~0.3 vol.-%). Likewise, helium content was sometimes found to be higher than atmospheric. OLGA data match well with the gas composition data of bubbeling gases sampled directly from the wellhead.
Effects of variable beach morphology, storm surges and aquifer parameters on the salinity distribution in the deep subsurface of a high energy beach – a generic modelling approach
Authors: Meyer Rena , Greskowiak Janek , Massmann Gudrun
Published: February 2023

Beach aquifers are the contact zone between the terrestrial groundwater and the ocean. Where the fresh groundwater mixes with the recirculating saltwater biogeochemical reactions take place and change the composition of the water. These biogeochemical reactions and resulting element net fluxes are linked to residence times and dispersive mixing processes that depend on dynamic density-driven groundwater flow and transport processes. In the present study we investigate the effect of dynamic hydro- and morphological boundary conditions and aquifer parameters on the groundwater flow- and transport processes in the deep subsurface of a high energy beach along a 2D transect perpendicular to the shore by means of a density-driven flow and transport model (SEAWAT). The ‘classical’ concept of a beach aquifer in the intertidal zone describes the stable establishment of three separated, layered water bodies. The fresh water discharge tube (‘FDT’) separates the wave and tide induced upper saline plume (‘USP’) from the saltwater wedge (‘SW’). Recent research challenges this concept of stable position of water bodies under high energy beach conditions which are characterized by high wave and tidal amplitudes. Our modelling results show that dynamic beach morphology has an important effect on the spatio-temporal flow and transport patterns as well as on the salt distribution and residence times in the deep beach aquifer and results in the formation of several time variable FDTs and USPs. Moreover, our research shows the sensitivities of the freshwater-saltwater interface in the subsurface to hydraulic conductivity, anisotropy, dispersion and boundary conditions like storm surges and fresh water inflow. The result is a complex, temporally and spatially variable picture of the ‘classical’ stable USP with dynamic interfaces. Hence, our results elucidate the physical conditions in the deep subsurface that are relevant for the spatio-temporal distribution of chemical reactions that are linked to the mixing interfaces between the water bodies. As a consequence the biochemical reactions might be enhanced with effects on the element net fluxes to the sea. 
Machine learning detection of dust impact signals observed by the Solar Orbiter
Authors: Kvammen Andreas , Wickstrøm Kristoffer , Kociscak Samuel , Vaverka Jakub , Nouzak Libor , Zaslavsky Arnaud , Rackovic Babic Kristina , Gjelsvik Amalie , Pisa David , Soucek Jan , Mann Ingrid
Published: February 2023

At present, ongoing space missions (PSP, SolO) provide the opportunity to closely observe the dust distribution in the inner solar system. It is however challenging to automatically detect and separate dust impact signals from other observed features for two main reasons. Firstly, since the spacecraft charging causes variable shapes of the dust signals, and secondly because electromagnetic waves (such as solitary waves) may induce resembling electric field signals.In this presentation, we propose a novel method, based on artificial intelligence, for detecting dust impacts in Solar Orbiter observations with high accuracy. Two supervised machine learning approaches are considered: the support vector machine (SVM) classifier and the convolutional neural network (CNN) classifier. Furthermore, we compare the performance of the machine learning classifiers to the currently used on-board classification algorithm and analyze 2 years of Solar Orbiter data.Overall, we conclude that detection of dust signals is a suitable task for machine learning techniques. The convolutional neural network achieves the highest performance with 96% ± 1% overall classification accuracy and 94% ± 2% dust detection precision, a significant improvement to the currently used on-board classifier with 85% overall classification accuracy and 75% dust detection precision. In addition, both the support vector machine and the convolutional neural network detect more dust particles (on average) than the on-board classification algorithm, with 16% ± 1% and 18% ± 8% detection enhancement respectively.
Safety aspects of floating ice sheets under moving loads
Authors: Kalisch Henrik , Johnsen Kristoffer , Dinvay Evgueni , Parau Emilian
Published: February 2023

Winter roads on frozen lakes are an important part of the transportation infrastructure in several Northern countries. Authorities follow various plans for opening and closing roads, maintaining safety by checking ice thickness and instructing drivers. Many of these plans are based on Gold’s formula which relates the thickness of the ice cover to the allowable load based largely on empirical observations of ice failure or non-failure under various loading conditions.In the case of moving loads such as motorized vehicles, the speed of the load is an important factor in addition to ice strength considerations. Indeed, experience has shown that under certain conditions of speed, ice thickness and water depth, the deflection under a vehicle travelling on a floating ice sheet may be amplified considerably.Indeed, it was shown in [1] that a decelerating load can lead to constructive interference of waves which could exceed the critical stress for crack formation. Ice roads are particularly treacherous near the shore as the critical speed gets smaller due to decreasing depth. In addition, due to existing blowouts, traffic may have to be rerouted to avoid broken ice. In the present contribution, we consider the waves created by a load moving in a circular path. Following [2], we show that curved paths may also lead to constructive interference which may be more severe than the waves created by a decelerating load.[1] Dinvay, E., Kalisch, H. & Părău, E.I. Fully dispersive models for moving loads on ice sheets. J. Fluid Mech. 876, 122–149 (2019).[2] Johnsen, K., Kalisch, H. and Părău, E.I. Ship wave patterns on floating ice sheets. Scientific Reports, 12, 1-10 (2022). 
Agricultural Drought Monitoring using Satellite based Surface Soil Moisture Data
Authors: Palagiri Hussain , Pal Manali
Published: February 2023

Agricultural drought refers to a period with declining Soil Moisture (SM) content and consequent crop failure from water stress. SM plays an important role in indicating water stress and thereby identifying agricultural drought. Due to the lack of large scale, fine resolution, and accurate/quality SM many agricultural drought studies are mostly based on ground-based SM observations having limited spatiotemporal variability and cannot be applied for large scale studies. Microwave remote sensing showed capability in estimating geophysical properties like SM and paved the way for a continuous agricultural drought monitoring. European Space Agency (ESA) under Climate Change Initiative (CCI) developed an active-passive multi-satellite merged ESA CCI SM dataset. In this study, ESA CCI SM’s potential in agricultural drought monitoring is explored, by deriving Empirical Standardized Soil Moisture Index (ESSMI) to identify agricultural drought in Indian state of Telangana from 2001 to 2020. Telangana is a severely drought-prone state of India heavily impacted by significant water stress and water shortages due to frequent droughts. This increases the need for accurate agricultural drought characterization in the state. Keeping in mind the necessity of drought monitoring system for Telangana and availability of large-scale satellite soil moisture data from ESA CCI, this present study employs the ESSMI using the non-parametric distribution of ESA CCI SM data, to characterize the agricultural drought in drought prone Telangana. The efficiency of ESSMI in drought monitoring is evaluated by comparing it to the Standardised Precipitation Index (SPI) and Rainfall Anomalies (RFA) calculated from India Meteorogical Department (IMD) daily gridded rainfall data. Both the indices along with the RFA identified 2009 as dry year and 2020 as wet year. Temporal evolution of monthly drought identified by ESSMI showed monthly delayed response when compared with SPI, whereas yearly ESSMI showed consistency with SPI and RFA. Different classes of drought areas identified by ESSMI are compared with SPI which showed near normal and mild dry regions for most of the study period. ESSMI is able to effectively capture near normal to moderate drought events and shows a consistent association with the SPI and RFA both in short and long term (monthly and annual) temporal scale. The study showed the overall performance of ESSMI is reliable for agricultural drought monitoring and can be used to develop effective drought warning and risk management.
The formation and transport of nitrogen-containing species in aerosols over central mountain area of Taiwan using isotope analysis
Authors: Huang Ming-Hao , Chen Ting-Yu , Ren Haojia , Hung Hui-Ming
Published: February 2023

Particulate matter (PM) is one major air pollutant that affects human health and the radiation balance of the earth. Thus, it is essential to identify the sources of air pollutants to provide feasible control strategies. In this study, we investigated the size-dependent 15N and 18O isotope ratio of N-containing species in aerosols to specify their sources, transport, and formation processes. Aerosol samples of different size ranges were collected using a micro-orifice uniform deposit impactor (MOUDI) on a half-day basis over Xitou Experimental Forest of National Taiwan University (23.40°N, 120.47°E, 1178 m a.s.l.) site at the valley southwest to the central Metropolitan of Taiwan in April 2021. Due to its location and topography, Xitou is downstream of the local circulation, which is dominated by the land-sea breeze and mountain-valley wind and brings the pollutants from the coastal industrial and agricultural activities to the forest during the daytime. Therefore, the samples collected at Xitou are a mixture of complex information. Chemical functional groups measurement was performed using Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR) technique beforehand to provide a grasp of the concentration-size distribution for both nitrate and ammonium as a reference to ensure sufficient nitrogen requirement for further isotope analysis at gas chromatography–isotope ratio mass spectrometer (GC-IRMS). The daily average concentration is 3.78±1.82 and 2.47±2.47 ug/m3 for ammonium (NH4+) and nitrate (NO3‑), respectively. The concentration during daytime is higher than at nighttime by a factor of 1.3-1.8. The result suggests that pollutants brought by the sea breeze windward contribute to nitrogen-containing aerosols. During a persistent 24-hour weak wind fog event, a significant concentration decreases for both substances (NH4+: 5.34 to 2.12 ug/m3 and NO3‑: 4.62 to 0.56 ug/m3) in PM10, likely due to sedimentation. The observed δ15N in NO3‑ increasing with diameter suggests NO3‑ at larger particles formed at the upper stream and NO3‑ at finer particles formed locally. On the other hand, δ18O in nitrate shows a similar trend which might be the contribution of RO2 as the oxidant locally. As NH4+ in aerosols is contributed by ammonia partitioning, δ15N-NH4+ only reflects the fractionation process during phase change and initial emission. The size-dependent trend of δ15N-NH4+ shows similar behavior to our previous study in December 2018 and reflects the time points of partitioning. Furthermore, the quantitative analysis of the transport and formation processes based on the size-dependent isotope will be deconvoluted to understand the partitioning of N-containing species in aerosols, which would be necessary for the pollution control strategy and their impact evaluation.
New paleomagnetic results from the Jingeryu Formation in the North China craton and their implications
Authors: Zhao Hanqing , Zhang Shihong , Qu Jianping , Yang Kunkun , Li Haiyan , Yang Tianshui , Wu Huaichun
Published: February 2023

We present new rock magnetic and paleomagnetic results from late Mesoproterozoic carbonate successions of the Jingeryu Formation (Fm) in the northern North China craton (NCC). Rock magnetic experiments, including thermomagnetic susceptibility curves, isothermal remanent magnetization (IRM) and thermal demagnetization of three-axis IRM, carried out for representative samples from the Jingeryu Fm indicate that both hematite and magnetite are abundant in the purplish-red limestone in the lower part of strata and the magnetic carriers of the pale blue limestone in the upper part are magnetite grains. For most samples subjected to stepwise thermal demagnetization, a high-temperature component (HTC) was isolated after removing a low-temperature component of viscous magnetic remanence acquired in recent geomagnetic fields. The HTC is characterized by steep inclinations, whose primary nature is supported by the presence of geomagnetic reversals. The similarities in paleomagnetic results and the correlatable lithologic sequence support that the Jingeryu Fm, the Nanfen Fm in the eastern Liaoning region in northeastern NCC and the Xinxing Fm in the Xuzhou region in southeastern NCC are correlative strata deposited in the polar region. Recently published radiogenic isotopic results constrain the depositional age of the Nanfen and Xinxing formations around ca. 1.1 Ga. Those high-latitude carbonate rocks widely distributed in the NCC predict an extraordinary climate condition around ca. 1.1 Ga.
Is secondary mineralization playing a pivotal role in recurring seismicity at Koyna-Warna Seismogenic Region of India: a geochemical perspective?
Authors: Halder Piyal , Sharma Anupam , Shukla Matsyendra Kumar , Kumar Kamlesh
Published: February 2023

Since the impoundment of the Shivajisagar Reservoir behind the Koyna Dam in 1962, numerous earthquakes have been felt in the Koyna-Warna Seismogenic Region of Western India. The mesoscopic and microscopic observations on the basement granitoid core samples, recovered under the Continental Deep Drilling Program of the Ministry of Earth sciences, reveal the precipitation of calcite and the formation of clay minerals (illite and chlorite) along the fractures and faults. The presence of these secondary minerals alongside the primary minerals like quartz and feldspar is further supported by X-ray Diffraction, which also points to the fracture scale chemical alteration as a result of fluid-rock interactions. It's interesting to note that the precipitation of these hydrophilic clay minerals along faults and fractures might promote slip by raising fluid pressure and lowering the shear strength of the faults. Thus, secondary mineralization due to fluid-rock interaction may have a contribution to the release of strain in form of seismic tremors. On the other hand, the neoformation of these hydrophilic clay minerals along fault/fracture surfaces may also cause rheological incongruity, which could lower the density as well as P and S wave velocities. Besides, hydrogen atoms in clay-bound water may influence neutron capture, leading to over-optimistic estimations of neutron porosity. Additionally, our study supports past geophysical anomalies found in the KFD1 borehole and infers that the geophysical anomalies correlating to the growing fracture density and fault system of the basement rocks are caused by chemical alteration due to fluid-rock interaction and subsequent secondary mineralization. So, this research offers important new understandings of geochemical activity in the context of geophysics and serves as a bridge between geochemistry and geophysics.
Mediterranean cyclone dynamics and climatology: current knowledge and research perspectives
Authors: Flaounas Emmanouil
Published: February 2023

A large number of intense cyclones occur every year in the Mediterranean basin, a relatively small and densely populated region, but also a worldwide climate-change hotspot. Given their importance for the variability of the regional climate and its extremes, Mediterranean cyclones have lately attracted much of attention, especially due to the broad range of severe socio-economic and environmental impacts that they produce.This talk aims at summarizing the concentrated knowledge of the last decade on the dynamics, climatology and relevant impacts of Mediterranean cyclones. We will especially focus on the processes that take place in different spatiotemporal scales triggering cyclogenesis and turning Mediterranean cyclones into catastrophic storms. We will also discuss the role of the unique regional geographical features therein, along with the influence of the latitudinal location of the Mediterranean basin. Finally, we will discuss the different subtypes of Mediterranean cyclones that develop in the region, devoting special attention to medicanes, i.e. cyclones with tropical characteristics and subjects of numerous recent studies. Througout the talk, research perspectives that advance the field of Mediterranean cyclones as a whole will be highlighted, along with current trends in community efforts within the framework of MedCyclones COST Action that address relevant topics to the complex dynamics of Mediterranean cyclones and consequent severe socio-economic impacts.