bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbiological quality of marine bathing waters under extreme environmental and social conditions
Authors: Mance Diana , Vukić Lušić Darija , Mance Davor
Published: February 2023

The quality of the sea is one of the most important factors according to which tourists decide whether to visit a particular coastal destination. The model for predicting the occurrence of microbiological contaminants must include data on both environmental factors and the economic activity of the coastal area. In recent years, we have observed the occurrence of extreme events both in nature and in society. In this work, we analyze the impact of extreme events (heavy rainfall, drought, extremely limited economic activity due to the pandemic COVID -19) on the occurrence of bacteriological contaminants on the selected beaches of the Liburnian area (Adriatic Sea, Croatia).This work was supported by the University of Rijeka under the project number: uniri-pr-prirod-19-24.
Arctic marginal ice zone changes in the GREP ensemble reanalysis product
Authors: Iovino Doroteaciro , Selivanova Julia , Cocetta Francesco
Published: February 2023

The rapid decline of the Arctic sea ice cover is a primary indicator of Earth’s changing climate. The variability of ice-covered area plays a crucial role in the modulating the ocean-atmosphere exchange. Knowledge of ice properties and their variability is necessary for an adequate simulation of those fluxes. Yet the response of September sea ice area or extent (SIA/SIE) is underestimated compared to observations in many global climate models.Global ocean reanalyses provide consistent and comprehensive records of sea ice variables and are of pivotal significance for climate studies also in polar regions.  We present the temporal and spatial variability of Arctic sea ice area in the CMEMS ensemble of global ocean reanalyses (GREP), from 1993 onward. We assess the accuracy of GREP in reproducing the evolution in time and space of total sea ice and discriminating between the marginal ice zone (MIZ) from consolidated pack ice. The MIZ properties markedly differ from the thicker, quasi-continuous ice cover of the inner pack, strongly influencing various atmosphere–ocean fluxes, especially the heat flux. The MIZ has become a significant component of contemporary Arctic sea ice cover, with a summer area comparable to that occupied by pack ice. The trend towards the MIZ is set to accelerate.Compared to satellite products (OSISAF and CDR), GREP provides consistent estimates of recent changes in the Arctic sea ice area and properly reproduces observed interannual and seasonal variability, linear trend, as well as record highs and lows. For sea ice classes, the ensemble spread is comparable to the spread among observational estimates that is as large as the ensemble spread. GREP is shown to properly represent the variability of MIZ area during the growing and melting seasons, as well as their minima and maxima. More evident discrepancies between GREP and satellite products occur during summer, when the MIZ amount increases, causing a spread widening among individual reanalyses.Our analysis suggests that GREP can be used to get a robust estimate of current Arctic sea ice state and recent trends in sea ice properties.
Application of autonomous surveys technologies for the evaluation of habitat restoration interventions sites on coastal areas
Authors: Scanu Sergio , Bonamano Simone , Madonia Alice , Piermattei Viviana , Resnati Arianna , Scagnoli Elena , Varini Fabrizio , Piazzolla Daniele
Published: February 2023

Among the objectives of marine ecology recently emerges the one concerning the maintenance and recovery of the ecological functions of ecosystems. This is particularly evident in the coastal marine environment, which is rich in habitats and species that provide many essential ecosystem services, like seagrasses. Seagrasses are important and productive coastal systems that provide nursery areas, carbon sequestration, protection from erosion, bioremediation, and oxygen production.Seagrasses are subject to both indirect and direct impacts. Among the indirect impacts, the one linked to the perturbations of the sedimentary dynamics of the coastal marine environment, caused by various factors, such as changes in land use, regulation of water basins, and climate change, is particularly significant. Among the direct impacts, the one caused by anchorages or in general by all activities involving the destruction of substrates is significant (e.g., illegal fishing, development of coastal infrastructure, construction, or expansion of existing ports).In this perspective, the use of innovative methodologies and technologies able to facilitate the monitoring activities of the coastal marine environment is particularly helpful. New cost-effective devices and autonomous survey technologies contribute to the optimization of the cost-benefit ratio in field survey activities, to the limitation of the impacts of the survey activities themselves on the habitats, and to favor the acquisition of more real-time data.
Radar forward modelling as a precursor for statistical inference
Authors: Muhle Leah Sophie , Moss Guy , Henry A. Clara J. , Drews Reinhard
Published: February 2023

Projections of the future development of the Antarctic Ice Sheet still exhibit a large degree of uncertainty due to difficulties in constraining parameters of ice-flow models such as basal boundary conditions. Deriving better estimates of these parameters from radargrams could greatly improve model accuracy, but integration of inferred radar attributes into ice-flow models is not yet widespread.Here, we develop a radar forward modeling framework that is geared to train a machine learning workflow (likely simulation-based inference) to extract radar attributes such as the internal stratigraphy and basal boundary conditions (e.g., frozen vs. wet) from radar data. The workflow starts with ice-dynamic forward models predicting physically sound stratigraphies and internal/basal temperatures for synthetic flow settings using shallow ice, shallow shelf and higher order ice-flow models. This is then used as input to the radar simulator (here gprMax), which calculates the radar image produced by such a stratigraphy. To do so, we match the synthetic permittivities of the modeled stratigraphy with statistical properties known from ice-core logging data and prescribe temperature dependent attenuation via an Arrhenius relation. gprMax is optimized for acceleration using GPUs which can be efficiently employed when solving the FDTD discretized Maxwell equations. Currently, 200 m wide and 500 m deep sections can be simulated on a single NVIDIA GeForce RTX 2070 Super graphics card within 390 minutes. The runtime can be substantially improved in a HPC environment. In order to obtain radar simulations comparable with observations, we also add system specific noise and contributions from volume scattering with variable surface roughness. Here, we focus on 50 MHz pulse radar for which we have many observational counterparts. However, the workflow is designed to encompass multiple ice-dynamic settings and different radar frequencies.The application of physical forward models will result in physically meaningful radargrams which are indistinguishable from observations. This provides a tool to create datasets for training machine learning workflows for inference without the limitations of hand-labeled data.
Enhanced situational awareness in Finland using atmospheric (and other) space-based observations
Authors: Ialongo Iolanda , Virta Henrik , Hakkarainen Janne , Szelag Monika , Sundström Anu-Maija , Tamminen Johanna
Published: February 2023

New remote sensing satellites for Earth Observation provide information to enhance situational awareness during exceptional socio-economic and natural events. Specifically, satellite-based observations of air pollutants, when combined with auxiliary (spaceborne and not) data, can provide new insights on societal and economic changes taking place around the world. Here we present a few applications of space-based atmospheric observations to support Finnish authorities. A recent history of such episodes includes: monitoring air quality changes in Helsinki during the COVID-19 pandemic; assessing methane emissions from the NordStream pipeline leakage over the Baltic Sea; assessing the environmental and social effects of the war in Ukraine as part of Finnish international cooperation projects. We integrate multiple data sources acquired by different spaceborne sensors including, e.g., the nitrogen dioxide (NO2) retrievals from the Copernicus Sentinel-5 Precursor/TROPOMI (TROPOspheric Monitoring Instrument), Sentinel-2 false color imagery, NASA VIIRS fire products as well as models and other environmental data.
The expected effect of climate change on snowfall amounts and snow depth in the major urban areas of Romania
Authors: Hrițac Robert , Sfîcă Lucian , Breabăn Iuliana-Gabriela , Amihăesei Vlad-Alexandru
Published: February 2023

Snowfall and snow depth are important elements of the climate system which can have a significant impact on the transport sector, local economy, water resources and local thermal regime.This study aims to identify the future trends of snowfall and snow depth in the most important urban areas in Romania, based on high-resolution regional climate models (RCM) data, made available through the EURO-CORDEX, and bias-corrected RCM simulations available în the RoCliB dataset. Ten different regional climate models with a target resolution of 10 km and two emission scenarios were considered, namely the moderate (RCP4.5) and business-as-usual (RCP8.5) scenarios. The study covers the interval from 2021 to 2100. In order to predict the future snow depth, snow cover duration and snowfall amounts based on the available parameters from the RCM simulations, it was necessary to identify the complex relationship between snowfall, snow melting, temperature and precipitation. In order to do this, we first extracted the ERA5 reanalysis data from 1981 to 2020 for each urban area, and then employed a Bayesian Regularized Neural Network (BRNN). The resulting model was used to predict the future variables for all major urban areas in Romania.A general trend of decreasing snowfall amounts, mean snow depth and snow cover duration was observed for all analyzed areas and for both emission scenarios. Important regional variations were also observed, with some areas no significant change for the 2021 – 2050 interval compared to the observation period, which could be explained mostly by the increasing winter precipitation predicted by the RCM simulation. The results also showed an increased possibility of some years virtually lacking any snow cover and snowfall precipitation, especially after 2050 in the business-as-usual scenario (RCP8.5). However, an increased variability was also observed, with extreme snowfall events remaining possible even in the latter half of the study interval.
Investigating the Source of the Slow Solar Wind Using Solar Orbiter Observations and the IRAP Solar Atmospheric Model
Authors: Thomas Simon , Rouillard Alexis , Lavarra Michael , Poirier Nicolas , Blelly Pierre-Louis
Published: February 2023

The slow solar wind can be separated into at least two different components: a dense, variable wind produced by helmet streamers and a more tenuous and Alfvénic component emitted by coronal holes. Previous studies have shown that the slow Alfvénic wind is associated with enhanced alpha particle abundances, strong proton beams, and large alpha-to-proton temperature ratios: typical properties of the fast wind known to originate from inside large coronal holes. Recent combined in-situ and remote-observation campaigns by the Solar Orbiter mission exploiting the Proton and Alpha particle Sensor (SWA-PAS) can help us to study the relationship between the Alfvénic slow wind and coronal holes. We exploit these latest observations in conjunction with the newly-developed multi-species IRAP Solar Atmospheric Model (ISAM) model to study the coronal conditions that favour the production of an Alfvénic slow wind. ISAM simulates the coupled transport of both neutral and charged particles between the chromosphere and the corona, including a self-consistent treatment of collisional and ionisation processes, as well as detailed energy and heat flux conservation equations. In this study we discuss how the simulated alpha to proton ratios are modulated in response to different coronal heating rates and discuss these simulation results in light of recent Solar Orbiter measurements. The results presented here were funded by the European Research Council through the SLOW SOURCE project grant number DLV-819189.
The role of seasonal variation of precipitation/recharge for different climates in karst genesis behaviors
Authors: Jiang Chuanyin , Jourde Hervé , Wang Xiaoguang
Published: February 2023

Recharge is an important factor controlling dissolution processes during speleogenesis of karst aquifers. In former studies simplified assumptions were considered, where a maximum recharge rate is assumed while its fluctuation is ignored. Under the latter assumption, the karst genesis is clearly divided into two successive processes characterized by either a hydraulic head limitation (hydraulic control) or a flow rate limitation (catchment control). In this study, we consider a karst system evolving according to a maximum recharge rate linked to the seasonal variation of precipitation, which may lead to speleogenesis processes under hydraulic control or catchment control from the beginning of the karst genesis. We found that, without considering the recharge fluctuation, the enlargement of fractures as well as the dimensions of dissolving area under a long-term evolution tends to be underestimated. Moreover, in the cases of a large catchment area, the time required to reach the final dissolution patterns tends to be underestimated (i.e., earlier breakthrough), while it tends to be overestimated in the cases of a small catchment area. In addition, the flow focusing during the karst genesis may be interrupted during dry seasons when the recharge regime is under catchment control. This may cause a stagnation in the evolution of flow channeling or even a less localized flow field. This study highlights the importance of recharge fluctuation in modeling karst genesis, which may have important engineering implications for the management of karst aquifers or the leakage risk prediction at dam sites.
A review of Water Use Efficiency across space and time
Authors: Fatichi Simone , Paschalis Athanasios , Bonetti Sara , Manoli Gabriele , Pappas Christoforos
Published: February 2023

Water Use Efficiency (WUE) is the variable linking assimilation and storage of carbon in plants with the release of water through transpiration. In this study, we combine multiple datasets including global scale leaf-level gas exchange measurements, tree-ring isotopes, flux-tower observations, and remote sensing products with mechanistic terrestrial biosphere modeling to evaluate whether WUE depends on precipitation or aridity levels and how changes in vapor pressure deficit affect ecosystem scale WUE and intrinsic water use efficiency (IWUE). A constrained range of WUE values across ecosystems and climates are observed with few noticeable exceptions. Observations and model simulations converge towards a weak WUE dependency on precipitation or aridity conditions.Numerical simulations with a mechanistic model reveal two distinct signatures of VPD on site level WUE and IWUE, with high VPD resulting in increased IWUE, but decreased WUE. Relations with soil moisture are instead more complex and non-monotonic. Multiple data sources in combination with mechanistic modeling offer new insights on WUE variability across spatial and temporal scales and provide reference WUE values for future comparisons.
How to detect marine heatwaves in a fjord-like environment ? Study case of the semi-enclosed inner seas of North Patagonia
Authors: Pujol Cécile , Pérez-Santos Iván , Barth Alexander , Linford Pamela , Alvera-Azcárate Aida
Published: February 2023

Marine heatwaves (MHWs) are described as anomalously warm temperature events over a portion of the ocean during at least five consecutive days, developing in both coastal and open-ocean environments.MHWs have been subject to numerous studies over the last years and it has been proved that their frequency and intensity is increasing through the decades in connection with human-induced global warming. Most of the studies are focusing on open-ocean MHW events and few in coastal environments, principally due to the lack of adequate data. Indeed, the detection of MHWs requires a long-term climatology of the ocean’s surface temperature, generally made with satellite data. Nevertheless, the complexity of coastal environments makes the use of satellite data non-optimal because of insufficient temporal coverage with high resolution data and interferences with land systems.The primary purpose of this study is to detect MHWs in a semi enclosed sea, with the study case of the Sea of Chiloé, North Chilean Patagonia. This sea is characterised by multiple fjords and channel systems, and has a cloudy and rainy climate; consequently, this kind of environment is not compatible with the use of satellite data to build the long-term climatology of the sea temperature at a high resolution required to detect the MHWs. Here, we use another way to calculate the climatology, using in situ data and interpolating them in order to have a continuous field. Indeed, the inner seas of North Patagonia have been quite well sampled across the years, with measurements realised since the 1950s, spatially scattered in all the regions at both surface and depth (including fjords and channels). To spatially interpolate these data, we used the tool DIVAnd (Data-Interpolating Variational Analysis) which allows to spatially interpolate in an optimal way discrete observations onto a regular grid, taking advantage of the information in the 4 dimensions. Doing this interpolation, we got a monthly climatology at 32 different depths, from the surface to 400m. MHWs were then detected by comparing the climatology to the local temperature in the Reloncaví Sound, in the Northern part of the Sea of Chiloé, where an anchored buoy recording the temperature of the sea surface since 2017 is present. We focused on MHWs that occurred during the last five years. Strong ones were detected during summers 2021 and 2022: two successive very intense and brief events occurred in January and February 2021, and several short successive events with increasing intensity from November 2021 to February 2022. We also realised the comparison between MHWs detected using in situ data and detected using satellite data.
Forest soil and deadwood CH4 fluxes in response to warming, increased precipitation, nitrogen fertilization and biochar addition across a Norwegian spruce age-management gradient
Authors: Johannesson Carl-Fredrik , Larsen Klaus Steenberg , Nordén Jenni , Silvennoinen Hanna
Published: February 2023

Methane (CH4) is the second largest contributor to global warming and the importance of reducing net CH4 emissions was recently highlighted through the 2021 Global Methane Pledge. Upland forest soils are most often acting as CH4 sinks, but forest management – for example clear cutting and nitrogen (N) fertilization – carry the potential to turn CH4 sinks into CH4 sources. However, little is currently known about the underlying mechanisms and to what extent forest management affects the fluxes. Furthermore, the role of deadwood in the CH4 cycle is poorly understood and quantified but has recently received increased attention. Deadwood, like soils, can act both as a sink and a source of CH4 and the few available studies indicate that tree species, decay class and wood density are important regulators of CH4 cycling in deadwood.In the ForBioFunCtioN-project, we utilize state-of-the-art technology (LI-7810 Trace Gas Analyzer, LI-COR®) for in situ measurements of soil-atmosphere and deadwood-atmosphere exchange of CO2 and CH4 in an extensive climate and management manipulation experiment. Treatments include warming with open-top chambers, increased precipitation (on average 25 mm/year during the snow-free period), N fertilization (NH4NO3 150 kg/ha) and biochar addition (10 t/ha) in a total of 12 treatment combinations (n = 144) across five Norwegian spruce dominated bilberry forest sites spanning from a recent clear-cut to mature managed (80 years) and old unmanaged (140 years) stands.Here, we present the experimental setup of ForBioFunCtioN and soil and deadwood CH4 flux measurements from the snow-free period in 2021 and 2022. Initial results showed that N fertilization decreased net soil CH4 consumption and that, while at rare occasions functioning as a sink, the Norwegian spruce deadwood was almost exclusively a source of CH4. The source strength of deadwood differed substantially between sites but CH4 efflux from deadwood increased by biochar addition at all sites.
Links between weather and seasonal influenza epidemics
Authors: Kyselý Jan , Hanzlíková Hana , Urban Aleš , Plavcová Eva , Kynčl Jan
Published: February 2023

Links between weather variability, influenza/acute respiratory infections (ARI), and human health are extremely complex in the cold season, and their explanation remains uncertain. It is not clear whether the winter mortality peak is related rather to low ambient temperatures or ARI, and how weather variability may modify transmission patterns of ARI and related mortality. This study investigates links between weather characteristics, influenza/ARI epidemics and all-cause mortality in the population of the Czech Republic (Central Europe), by employing long-term epidemiological and meteorological datasets over the 1982/83 to 2019/20 epidemics seasons. The links are analysed with respect to the predominant type of influenza virus in each season (A/H3N2 and A/H1N1 subtypes, and B lineages). We focus on i) identification of meteorological conditions associated with epidemics, ii) how timing of the epidemics and their magnitude are linked to weather characteristics, and iii) whether there are synergetic effects of cold weather and epidemics on the mortality impacts. Preliminary results suggest that high excess mortality during influenza epidemics was associated with low temperatures while above-average temperatures were linked to lower morbidity and mortality impacts. The role of other meteorological characteristics is less clear. Understanding weather conditions that increase the transmission and survival of influenza and respiratory viruses could help to better inform at-risk populations, implement preventive measures, and mitigate the negative impacts of influenza and ARI.
The effect of ionospheric conductance on reconnection estimates based on ionospheric observations
Authors: Gasparini Sara , Hatch Spencer M. , Reistad Jone P. , Ohma Anders , Laundal Karl M.
Published: February 2023

Ground magnetometer measurements are frequently used to study ionospheric electrodynamics. It is possible to relate and combine ground magnetometer measurements with ionospheric convection measurements through the  ionospheric Ohm’s law. It is therefore important to have knowledge of the auroral conductances in order to utilize both these sources of information together when describing the 2D ionospheric electrodynamics. However, auroral conductances are very difficult to evaluate. In this study we use a new data assimilation technique on an event study to investigate the effect of different methods to retrieve auroral conductances. We focus on the effect on estimates of nightside reconnection, based on ionospheric convection and optical observations of the open closed boundary. We show that different choices of conductance lead to differences in ionospheric convection velocities, and hence differences in estimates of the reconnection electric fields. 
The inner life of the Atlantic ITCZ
Authors: Windmiller Julia , Stevens Bjorn
Published: February 2023

The intertropical convergence zone (ITCZ) is a central component of the global circulation system, but remarkably little is known about the dynamical and thermodynamical structure of the convergence zone itself. This is true even for the structure of the low-level convergence that gives the ITCZ its name. Following on from the major international field campaigns in the 1960s and 70s, we performed extensive atmospheric profiling of the Atlantic ITCZ during a ship-based measurement campaign aboard the research vessel SONNE in summer 2021. Combining the data we collected during our north-south crossing of the ITCZ with reanalysis data shows that there are generally two low-level convergence lines that roughly mark the southern and northern edges of the region of intense precipitation. Based on the location of these two edges, we construct a composite view of the structure of the Atlantic ITCZ. The ITCZ, far from being simply a region of enhanced deep convection, has a rich inner life, i.e., a rich dynamical and thermodynamic structure that changes throughout the course of the year and has a northern edge that differs systematically from the southern edge. 
Fengyun Program and Solar Observation Activities
Authors: Zhang Peng , Qi Jin , Ye Xin , Huang Yu , Zhu Ping
Published: February 2023

Fengyun 3 series (FY-3) is the second generation polar orbiting meteorological satellite in China. There are 5 satellites have been launched since the first satellite FY-3A in 2008. The solar irradiance is one of important parameters to measure by FY-3 series. The instrument to measure the solar irradiance is called Solar Irradiance Monitor (SIM). The SIM was deployed on the orbit since FY-3A (morning orbit AM) in 2008 and FY-3B (afternoon orbit PM) in 2010. SIM was upgraded to SIM-II mounted on FY-3C (AM orbit) in 2013. The sensitivity, absolute accuracy and stability of the instrument has been improved with the more accurate control on the solar disk tracking system and instrument environment temperature maintaining system. The SIM-II together with the Solar Spectral Irradiation Monitor (SSIM) have been deployed on the orbit mounted on FY-3E (early-morning orbit EM) in 2021. This presentation overviews the FY program. The specification and performance of SIM, SIM-II and SSIM have been illustrated. The measured Total Solar Irradiance (TSI) product has been compared with the similar measurements on SOHO/VIRGO, SORCE, TSIS-1, etc. The future plan for the solar measurements in FY-3 series has been presented in the last part.
Evolution of the Concordia seismological observatory station CCD (GEOSCOPE network): a new post-hole installation on Antarctica plateau
Authors: Zigone Dimitri , Bes de Berc Maxime , Danecek Peter , Steyer Alain , Zanolin Francesco , Lambotte Sophie , Alemany Olivier , Possenti Philippe , Cavaliere Adriano , Marino Stefano , Thore Jean-Yves , Maggi Alessia , Bernard Armelle , Leveque Jean-Jacques , Rivera Luis , Vallée Martin , Leroy Nicolas , Stutzmann Eleonore , Pesqueira Frédéric , Pardo Constanza
Published: February 2023

In the Southern Hemisphere, the prevalence of the oceans and the difficulty of access to land result in a lack of coverage of seismological station which is a strong limitation Our knowledge of the Earth’s structures and of large earthquakes sources. This is particularly critical inside the Antarctic continent where only two permanent seismological stations are currently available (QSPA and CCD). Among them, the seismological station CCD is a joint program between EOST (Strasbourg) and INGV (Roma) and is installed at the Concordia scientific base (75°S 123°E). This observatory, built in 2000 with state-of-the-art surface instrumentation installed in a vault made of snow-covered containers, meets the required quality criteria and has been part of the GEOSCOPE network since 2008. However, it has become necessary to replace this installation for safety reasons, recurring snow coverage issues and seismological performances. The existing seismic vault is deformed by the hydrostatic pressure of the snow. Its proximity to the base causes strong daytime noise (~30 dB) at high frequencies (>1 Hz); the unconsolidated layer of snow about 100m thick forms a waveguide that traps anthropogenic noise from the base. In addition, a coupling defect of the instruments in contact with the snow limits the performance at low frequencies (< 0.03 Hz) on the horizontal channels.Eight years ago, we proposed to install a borehole seismometer at a depth of 120m to limit the waveguide effects. A new shelter on stilt and the borehole drilling were carried out in 2018/2019. The installation of all the instrumentation has been completed by our team in January 2020. The analyses of the data show that the high-frequency disturbances are very largely attenuated (-30 dB at 10 Hz) compared to the surface installation and that the horizontal channels have a lower noise level at low frequencies (-20 dB at 0.01Hz). In addition, data for all components are below the standard noise model for frequencies between 5 and 9Hz, which already makes this new station one of the quietest installations in the world for those frequencies. A few problems remain to be solved, such as atmospheric pressure-related perturbations for periods longer than 600s on the vertical component. We are currently implementing several patches to try to better insulate the borehole. Updates will be presented during the meeting. Despite this problem at long period, the new CCD borehole stations is a success with better-than-expected performances at all periods shorter than 500s. The data produced are now distributed in the world data centers as G.CCD.20.
Crustal structure observed by the InSight mission to Mars
Authors: Kim Doyeon , Stähler Simon , Boehm Christian , Lekic Ved , Giardini Domenico , Ceylan Savas , Clinton John , Davis Paul , Duran Cecilia , Khan Amir , Knapmeyer-Endrun Brigitte , Maguire Ross , Panning Mark , Plesa Ana-Catalina , Schmerr Nicholas , Wieczorek Mark , Zenhäusern Géraldine , Lognonné Philippe , Banerdt William
Published: February 2023

After more than 4 Earth years of operation on the martian surface monitoring the planet’s ground vibrations, the InSight’s seismometer is now retired. Throughout the mission, analyses of body waves from marsquakes and impacts have led to important discoveries about the martian interior structure of the crust, mantle, and core. Recent detection of surface waves, together with gravimetric modeling enabled the characterization of crustal structure variations away from the InSight landing site and showed that average crustal velocity and density structure is similar between the northern lowlands and the southern highlands. Especially for the observed overtones and multi-orbiting surface waves in S1222a, we find the depth sensitivity expands down to the uppermost mantle close to 90 km. Furthermore, our 3D wavefield simulations show significantly broadened volumetric sensitivity of the higher-orbit surface waves. These new constraints obtained by our surface wave analyses provide an important opportunity not only to refine and verify our previous radially symmetric models of the planet’s interior structure but also to improve understanding of seismo-tectonic environments on Mars. Here, we summarize our recent effort in the analyses of surface waves on Mars and discuss the inferred crustal property and its global implications.
Tropical cyclone frequency and infiltration changes recorded by speleothem trace metal signatures
Authors: Warken Sophie F , Mielke Aaron , Schorndorf Nils , Gafriller Judith , Keppler Frank , Winter Amos , Höpker Sebastian N. , Hartland Adam , Vieten Rolf , Schröder-Ritzrau Andrea , Frank Norbert
Published: February 2023

Trace element abundances such as Mg/Ca ratios are frequently used in speleothems to support climate reconstructions or karst processes. However, signals of short-lived extreme events (e.g., droughts or strong rainfall events and tropical cyclones) are often concealed within the record of the classical stable isotope and elemental records due to dissolution and mixing processes within the soil and karst zone. On the contrary, drip water transition metal ratios and their binding affinities to particles and organic ligands, suggested faster transport in response to strong infiltration events and thus possibly reflect seasonal and/or even event-based rainfall variations (Warken et al., 2022). Here we assess replicated LA-ICPMS records of elemental abundances in two modern speleothems from Larga Cave, Puerto Rico, to explore their potential as indicators of extreme precipitation events. Speleothem Mg/Ca ratios show a broad co-variability with δ18O and δ13C values, and are interpreted as sensitive indicators of regional hydrology (δ18O) and local water balance (Mg/Ca, δ13C). Analogous to the drip water signature, we identify a common pattern of element ratios typically associated with particle and/or organic ligand fluxes (e.g., Cu/Ca, Ni/Ca, Zn/Ca, Al/Ca, Cu/Ni, Cu/Co, …), which differs from the δ18O and Mg/Ca records. In particular, we observe a similarity of the infiltration-sensitive proxies to historic Hurricane and tropical cyclone occurrence since 1850 AD. This suggests that the trace metal pattern observed in the drip water is recorded by the stalagmites, and that these elements are most promising candidates as indicators for fast infiltration changes, and possibly even tropical cyclone frequency. Furthermore, we explore a long speleothem record covering the last glacial period between 40.8 and 12.2 ka BP. In line with the modern interpretation, trace elements such as Cu/Ca or Zn/Ca indicate higher cyclone activity during the Holocene as compared to the glacial cold phase. In addition, the record reveals strong variations on the millennial scale which coincide with the onsets of warm and wet interstadial phases associated with abrupt warming events in the northern hemisphere and northward shifts of the Intertropical Convergence Zone. These observations support that mobilization and transport of organic ligands and associated elements is effectively coupled to infiltration.Reference:Warken, S. F., Kuchalski, L., Schröder-Ritzrau, A., Vieten, R., Schmidt, M., Hoepker, S., Hartland, A., Spötl, C., & Frank, N. (2022). The impact of seasonal and event-based infiltration on transition metals (Cu, Ni, Co) in tropical cave drip waters. Rapid Communications in Mass Spectrometry e9278. https://doi.org/10.1002/rcm.9278
Numerical simulation of ocean currents in the Northern Mozambique
Authors: Doost Mohammadi Moein , Bolla Pittaluga Michele , Magaldi Marcello Gatimu , Mazzino Andrea
Published: February 2023

A three-dimensional Regional Ocean Modelling System (ROMS) has been implemented to investigate hydrodynamic circulation patterns in the Northern Mozambique Channel and their role on turbidity current generation and sediment distribution in the submarine canyons. A high-resolution (~ 100m) bathymetry data of the Palma Bay and its offshore area was blended with a global gridded bathymetry (GEBCO) with 15 arc-seconds (~ 400m) resolution to cover the area of interest. Our main goal is to better understand deeper currents in the Mozambique Channel that are less well-established, and their ability to transport seabed sediment, by means of analysis of water structure according to T-S diagrams. There are debates on existence of some specific oceanographic features and unanswered questions regarding origins of the passing mesoscale eddies which dominate the circulation in the Mozambique Channel. Furthermore, we are also interested in knowing the effects of the presence of submarine canyons on adjacent canyons and their contribution to the circulation patterns and other physical processes in the area. Preliminary results highlight the importance of small-scale features for the circulation in area of interest.
Positive feedback between rates of rock mass weathering and landscape lowering through fluvial and hillslope erosion in the High Himalaya of Bhutan
Authors: de Palezieux Larissa , Leith Kerry , Loew Simon
Published: February 2023

River systems provide a primary means of sediment production and transport in mountain environments. While sediment transport is mainly governed by stream power, the rate of rock mass weathering is a function of rock mechanical properties and the local climatic conditions. Here, we investigate the interaction between fluvial incision and weathering rates in two alpine catchments in the NW of Bhutan. The study region is characterized by three distinct geomorphic domains including broad alluvial plains, with detachment-limited regimes, transport-limited fluvial valleys with steep hillslopes and high relief, and glacially overprinted low-relief landscapes at the foot of the High Himalayan peaks. The two major drainage basins, the Wang basin in the West and the Punatshang basin in the East, both traverse these geomorphic domains, yet show marked differences in profile view, with the alluvial plain of the Wang basin located 1000 m higher than the Punatshang basin.In this study we combine river profile analyses with records of rock mass weathering and mapped morphological markers regarding the spatial extent of erosional regimes (past and present extent of alluvial infill and maximum glacial extent) to reconstruct the relative sequence of erosional events generating the present-day topography of the two basins. We find characteristic gradients in the degree of rock mass weathering throughout the hillslopes with fresh outcrops close to the river network and weathering grade increasing with elevation above the river channel. We interpret the higher degrees of weathering to represent the additional time available for rock mass weathering in parts of the landscape distal to the ongoing fluvial incision. While the general pattern of rock mass weathering is similar between the two basins, we observe on average higher degrees of weathering in the eastern basin (Punatshang). Although the difference in elevation of 1000 m between the two basins suggests a larger volume of sediment having been eroded in the Punatshang basin, we suggest the topographic lowering of this basin and the subsequent climatic changes (increases in mean annual temperature and total annual precipitation) to result in increased rates of rock mass weathering, which outpace those of fluvial incision.
Detection of slope deformation at the Tröllaskagi peninsula, N-Iceland, using Sentinel-1 D-InSAR time series (2016-2022)
Authors: Adalsteinsdottir Ása Dögg , Sæmundsson Þorsteinn , Buchelt Sebastian , Ullmann Tobias
Published: February 2023

Following last deglaciation, glacially eroded hillslopes of the Tröllaskagi peninsula in N-Iceland experienced intensive rockslide activity. In the Almenningar site, located on the outermost part of the peninsula, several rockslide features show active surface displacement, which have repeatedly caused major damages and hazardous conditions to a road crossing the area. Since 1977 the Icelandic Road and Coastal Administration (IRCA) has maintained regular measurements and in 2022, GNSS stations were installed for real time monitoring. These measurements indicate deformation rates up to 70 cm per year. Monitoring results further suggest a relationship between deformation and hydroclimatological factors. Furthermore, the front of the deformation area reaches the coast forming up to 60 m high cliffs where clear indications of extensive coastal erosion can be found. Whereas traditional landslide monitoring and field measurements can be expensive and time consuming, remote sensing methods such as Differential satellite Interferometric Synthetic Aperture Radar (D-InSAR) time series analysis has proven to be a valuable tool for large-scale slope deformation detection. In our study, we implement multitemporal D-InSAR methods, which decrease limiting factors like atmospheric delay, orbital errors and decorrelation. We use the Copernicus Sentinel-1 SAR satellite constellation with its 6 day (since 2022: 12 day) revisit time over Iceland. Besides the monitored Almenningar site, two additional sites in Tröllaskagi, Stífla and Siglufjarðarfjall, were selected for slope deformation detection due to their landform similarity and possible threat to infrastructure. The displacement time series was generated for the summers of 2016 through 2022 to (i) detect the spatio-temporal slope deformation patterns in Almenningar, Stífla and Siglufjarðarfjall, (ii) analyse if these landforms have similar deformation response to hydroclimatological conditions and/or seismic episodes and (iii) if there is noticeable difference in deformation rates at the coast or inland. The results of this research will be presented here. In conclusion, D-DInSAR provides useful information to analyse other rockslide features in Tröllaskagi and correlate detected deformation to hydroclimatological conditions and seismic episodes. Results will serve as an important support for hazard and risk assessment and contribute to further research on triggering factors.
Evolution of a plumbing system under the influence of variable ice load - The Pleiades volcanic complex, Antarctica
Authors: Rocchi Irene , Tomassini Alice , Masotta Matteo , Petrelli Maurizio , Ágreda López Mónica , Rocchi Sergio
Published: February 2023

The climate-controlled variations of the glacio-lithostatic load in glaciated terrains can potentially affect the tempo of volcanic eruptions, by modifying the pressure conditions acting on the underlying plumbing system. During glacial periods, increasing ice load hinders magma eruption, thus leading to prolonged residence time in the crust. This allows the magma to crystallise, differentiate and accumulate volatiles over a longer time span with respect to non-glacial periods.In Antarctica, volcanism in glaciated regions has been acting since the Miocene. In detail, in northern Victoria Land, volcanoes are located either in attenuated or thick cratonic lithosphere. Among the volcanic edifices built on thick crust, the quaternary Pleiades Volcanic Complex (PVC) is made up of some 20 monogenetic, partly overlapping scoria and spatter cones, that erupted over the last 900 ka. The erupted products range in composition from hawaiite to trachyte, defining a complete mildly Na-alkaline differentiation trend, which is quite unusual among alkaline monogenetic volcanic fields.Six samples from the PVC, representative of the whole differentiation trend, have been investigated by means of electron microscopy, electron microprobe and laser ablation ICP-MS. The parageneses of the rocks includes dominant feldspar and clinopyroxene with minor olivine. The mafic phenocrysts are characterised by significant resorption textures: specifically, the olivine presents deep embayments with absence of compositional zoning, while clinopyroxene frequently shows spongy texture and compositionally zoned mantle and rims, often with patchy and convoluted patterns.Petrography, textures and mineral chemistry suggest that the magma experienced first a rapid decompression, followed by a prolonged residence time, likely supported by increased ice load. During this time interval, resorption of the early formed mineral phases occurred, probably also enhanced by crustal assimilation processes, coupled with re-crystallization under isobaric conditions. Moreover, the prolonged residence time, coupled with the occurrence of (multiple) magma recharge(s) caused the mixing of a basaltic magma with other differentiated magmas stalling in the plumbing system, yielding to the formation of intermediate magma compositions. Finally, magma refilling of the plumbing system during an ice loss period, favoured the eruption. Machine-learning based thermo-barometric estimates consistently indicate crystallization of clinopyroxene at transcrustal pressures, ranging from the crust-mantle interface (early crystallization) to shallow crust (late crystallization in a shallow plumbing system under glacial load).
Geodatabase of structural data from North Victoria Land (Antarctica): a useful tool for geodynamic modelling
Authors: Bagnasco Alessio , Cianfarra Paola , Locatelli Michele , Crispini Laura , Balbi Evandro , Salvini Francesco , Federico Laura
Published: February 2023

Here we present an open access GIS project associated to a structural database which includes the geo-structural measurements (over 6000) collected in the field during the past Italian PNRA (National Antarctic Research Program) scientific expeditions from the year 1988 to 2021. The targeted research area is the North Victoria Land (NVL), Antarctica, between the 70°-76° S latitude and the 159°-171° E longitude.NVL is an area difficult to be accessed for direct geological studies on rocks due to the extensive ice/snow coverage (~5%) and few published studies with complete structural datasets are available so far.Our database is organized in various fields which include: number/code of the expedition, date, code of the site of field structural measurement, geographical coordinates of the field measurement site, elevation, toponyms, lithological classification, geological unit, description of any collected sample, name of the field data collector, classification, attitude of measured structural element (strike/trend, dip/plunge, dip/plunge direction), local magnetic declination at the date of the field survey.  Fault attributes include fault type (normal, reverse, strike-slip), rake of the slickenlines and sense of motion. Attributes of the extensional fractures/joints also include their dimension (height, H) and spacing (S).Moreover, the GIS project includes basic georeferenced maps such as: i) geological maps of NVL available in literature at 1:250.000 and 1:500.000 scale; ii) DEM of the bedrock and of the ice surface (from Bedmap 2); iii) the Radarsat mosaic of Antarctica; and iv) the MODIS mosaic of Antarctica.This queryable database allows to perform multiple geostatistical analyses and realise geothematic maps such as: i) the spatial variability of the main azimuthal structural trends at the regional scale; ii) the intensity of brittle deformation quantified by the H/S parameter (see contribution of Cianfarra et al. in this meeting); and iii) thematic geostructural maps (e.g: maps of the foliation traces, of strain partitioning or fractures distribution).These analyses, pivotal to better understand the tectonic framework of complex regions such as the NVL and to provide constraints supporting any geodynamic modelling, will greatly benefit from the extreme pliability and interoperability of such a database, which can be easily modified and expanded according to different scientific research needs by the production of newly derived data.
Groundwater solute transport simulation using global collocation radial basis function based meshfree method
Authors: Patel Sharad , Gaurav Kumar
Published: February 2023

We develop a global collocation based meshfree method for simulation of solute transport in the saturated aquifer formations. We prove that the projected model is free from the limitations of mesh or grid which are used in finite element method (FEM) and finite difference method (FDM). We apply this model on different one and two-dimensional synthetic aquifer problems with advection-dispersion phenomenon. The results of these problems demonstrate that the proposed model is free from the limitations of unstable convergence and has a fixed range (i.e., 2-3) of shape parameter hence it requires less number of simulations to calibrate the model. More importantly, the proposed model is simple to code and shows a higher degree of unanimity with the analytical solution, making it a viable alternative to grid-based traditional methods.  