bluuebunny/crossref_metadata_2025 huggingface dataset:
Conceptual Flood Inundation Modelling: Computationally Efficient Methods for Large Data-scarce River Basins
Authors: Unnithan S L Kesav , Biswal Basudev , Rüdiger Christoph , Dubey Amit Kumar
Published: March 2022

India is one of the world's most flood-prone countries, with 113 million people exposed to floods. Large-scale hydrological models integrated with complicated Navier–Stokes based hydraulic, and inundation models traditionally address flood preparedness, control, and mitigation. In addition to being highly data-intensive at the fine spatial and temporal resolution, this approach has a considerable computational cost that limits real-time applications. We employ the parameter-free Dynamic Budyko (DB) hydrological model to map observed precipitation with gridded runoff to overcome data scarcity. We propose a time-efficient Slope-corrected, Calibration-free, Iterative Flood Routing and Inundation Model (SCI-FRIM) framework that can be used with any hydrological model to generate a probability map of inundation. To model the catastrophic flood extents that the state of Kerala in India experienced during August 2018, we use gridded 0.25 deg × 0.25 deg IMD precipitation data. We use a parameter-free iterative approach to update flood velocity by assuming that river velocity does not fluctuate geographically across a particular river network at a given time instant. We pre-compute the iterative velocity and model the relationship between flood velocity-discharge and discharge-inundation height for each reach by combining the globally available SRTM/ASTER DEMs with empirically obtained river-reach geometry data (JPL). We compute the reach slope from the absolute vertical error-prone DEM by segmenting the river network into a series of independent channels and extracting the relationship between the channel pixel's elevation and the pixel's distance to the pour point. We use the Height Above Nearest Drainage (HAND) to map the probabilistic spatial extent corresponding to an ensemble of derived reach inundation heights. We then compare the proposed model with observed flood data points provided by the Kerala State Disaster Management Authority (KSDMA). The model captures up to 52% of 370,000 flood data points in a single run for the peak flood day within 15 minutes on a desktop computer. With reliable estimates of empirical bankfull discharge, the proposed model can achieve higher accuracy in lesser time.
Dimensional analysis and intercomparison of the basin time of concentration formulas
Authors: Evangelista Giulia , Claps Pierluigi
Published: March 2022

A wide literature dealing with the assessment of the critical time scale for basin hydrologic response exist worldwide. The time of concentration (tC) is recognized as the most frequently used time parameter, followed by the lag time (tL). However, despite the high sensitivity of design flood peaks to the estimated time parameter values, there is still no agreement on the conceptual and operational definitions of these two parameters, resulting in several different approaches and formulations available.

In our work, we suggest a conceptual approach to validate formulas of the basin time of concentration, with the aim of drawing some guidance in the choice of a robust formulation to be used in hydrological modelling and hydrograph design. To this end, 47 empirical and semi-empirical formulations to quantify tC have been selected and their structure compared in dimensional terms, using the hydraulic Chezy formula as a litmus paper. Using the river network morphology of 197 watersheds in north-western Italy we have then examined and compared the variability of the estimated average flow velocity within the most hydraulically compatible formulas.

Mindful of recent outcomes on tracer studies (see Azizian, 2019), our results lead to justify some of the coefficients of just a few of the empirical expressions of the critical basin travel time and to further clarify the distinction between tC and tL, according to some theoretical justifications discussed in Beven (2020).
Persistent configurations of the North Atlantic jet stream from the perspective of large deviation theory
Authors: Galfi Vera Melinda , Messori Gabriele
Published: March 2022

Unusual, long-lasting configurations of the North Atlantic jet stream affect the weather over Europe leading to persistent surface extremes. We study these persistent jet configurations in winter on intraseasonal and seasonal time scales using CMIP6 simulations, based on temporal averages of three jet indices: the jet latitude index, the jet speed index and the zonal jet index. We define these unusual configurations as long-lasting states, during which the jet stream is further south or further north, stronger or weaker, more split or more merged than usual. We estimate the probability of rare configurations, lasting at least 2 months, based on large deviation rate functions. The rate functions are asymmetric in case of the jet speed index, meaning that anomalously strong jet states are more persistent and more frequent than weak ones. Furthermore, we quantify the increased frequency of temperature and precipitation extremes over affected European regions. Here, we find a stronger link between jet events and precipitation extremes compared to temperature extremes. We observe the largest effects in case of precipitation extremes over the Mediterranean and Western Europe during anomalously strong jet configurations.
Detecting the preparatory phase of induced earthquake at The Geysers (California) using K-means and LSTM
Authors: Iaccarino Antonio Giovanni , Picozzi Matteo
Published: March 2022

What happens just before and generates a moderate to large earthquake is still on debate. Two different models are usually proposed. The first considers the main event as triggered by cascading effect from multiple random small earthquakes. The other one proposes the existence of a preparatory phase in which the seismicity slowly migrates towards the hypocentral zone loading stress on it, until the main event occurs.

In this work, we want to identify the preparatory process from catalogue data. We use data from The Geysers, a geothermal area in California (USA). Many studies showed that the seismicity of the area is triggered by the human activities related to the extraction of geo-energy.

Following the work done in Picozzi and Iaccarino (2021), we compute different features related to the seismicity around moderate events (M>3.5) and we use them as time-series. In this study, the features are computed following a fully causal procedure that make this analysis suitable for a real-time application. We apply both a supervised machine learning technique (LSTM Recurrent Neural Network) and an unsupervised clustering technique (K-means) to highlight the preparatory phase with respect to the background seismicity.

We show that, with both techniques, it is possible to identify a change in the seismicity just before most of the events studied. This confirms the existence, at least in some cases, of a preparatory phase for induced earthquakes at The Geysers.
On the impact of the effusion rate trend for the assessment of lava flow hazards 
Authors: Zuccarello Francesco
Published: March 2022

Lava flows are recurring and widespread hazards that affect areas around active volcanoes, having the potential to cause significant social and economic loss. In the last decades, physics-based models of lava flows have been proven effective and powerful tools to forecast and assess the hazard posed by effusive events. These models require different input parameters, such as the physical properties of the fluid (e.g., melt compositions, water content, rheological law, thermal properties) and the topography of the terrain. A critical parameter in physical-mathematical modelling is the effusion rate, i.e. the rate at which lava is discharged. Lava effusion rate is variable in time, strongly controlling the emplacement and run-out distance of lava flows. Nevertheless, both for assessing long-term hazards and for monitoring efforts during on-going eruptions, effusion rate is assumed to be constant or to have a bell-shaped time-dependent behavior. Here we present an analysis of the time-averaged discharge rates (TADRs, i.e. the effusion rate averaged over given periods) estimated for recent flank eruptions at Mt. Etna volcano (Italy) in order to define a possible generalized effusion rate trend to be used for the physical modeling of lava flows. The temporal series of TADRs, derived from field measurements and satellite thermal imagery, were normalized in order to obtain homogeneous curves in duration and sampling times, reducing redundancies and improving data consistency. Our analysis indicates that most of the effusion rate curves for flank eruptions of Etna are characterized by a fast waxing phase with the peak occurring between the 0.5 and 29% of the total eruption time, followed by a progressive decrease in the waning phase. By using the median values associated to the occurrence of effusion peaks and to the slope variations of descending curves in the waning phase, we estimated an averaged curve that was used to run numerical tests by means of the physics-based GPUFLOW model. Different tests were performed considering how the “characteristic effusion rate curve” could impact single vent scenarios, as well as on short- and long-term hazard maps. Statistics on the final emplacements revealed variations up to 20%, confirming the key role of the effusion rate in controlling the development of lava flow fields.
A General Perspective of Discharge-Area Relationship during Recession 
Authors: Kadu Akshay , Biswal Basudev
Published: March 2022

One of the compelling problems in hydrology is to predict discharge at a point in a river network without any historical data. Any solution to such a problem requires knowledge of how a drainage basin functions, thus linking its response to precipitation inputs with its physiological characteristics. In this regard, considerable efforts have been made to understand the link between basin size and peak discharge. The present study extends the discharge-area analysis to the recession domain. We assumed two dominant flow processes to exist in natural basins viz; Pure Surface Flow (PSF) and Mixed Surface Sub-surface Flow (MSSF). As the recession progresses, MSSF is expected to become the dominant flow generation mechanism in the basin. The MSSF is directly proportional to the total length of the saturated channel network or active drainage network (ADN) in a basin, which is directly proportional to the basin area. Thus, during the late recession period, the discharge is supposed to be directly proportional to the basin area. Using a geomorphological hydrologic response model, we tried to prove this direct relationship between discharge and basin area during the recession period. The results obtained are in agreement with our assumed hypothesis.
Soil quality assessment in a chronosequence of landslides in Garhwal Himalayas, Uttarakhand, India
Authors: goyal Deepesh , Joshi Varun
Published: March 2022

LANDSLIDES are one of the destructive geological processes that occur throughout the world. At global scale, the landslides are one of the major natural disaster which deteriorate the soil quality at a very large scale. In the Indian Himalayan Region (IHR), the Garhwal Himalayas of Uttarakhand landslides occurred very frequently in rainy season due to the presence of fragile rocks, active tectonic activity and unplanned anthropogenic activities. Landslides causes the loss of soil nutrients and vegetation which in turn deteriorate the soil quality. They can have an enormous effect on biodiversity and significantly alter the soil quality. The rate of soil development in essential for determining the recovering capacity of soil after the losses occurred due to landslides and erosion.

Therefore, the present study analyzed the natural recovery of soil quality in terms of soil characteristics with the passage of time (chronosequence) in 4 disturbed sites of different ages i.e., 6-year-old (L1 site), 16-year-old (L2 site), 21-year-old (L3 site) and 26-year-old (L4 site) including control (undisturbed) site in the Garhwal Himalayas of Uttarakhand. 76 soil samples were collected from all the selected sites at two depths i.e., 0-15cm and 15-30cm. The collected soil samples were analyzed for various physical (bulk density (BD), particle density (PD), total porosity (TP), moisture content (MC) and sand, silt and clay content) and chemical characteristics (pH, electrical conductivity (EC), soil organic carbon (SOC), soil organic matter (SOM), mineralisable nitrogen (MN), available phosphorus (AP) and available potassium (AK). Principal Component Analysis (PCA) was done with all the 14 variables which are significantly different in order to establish minimum data set (MDS). The MDS includes SOC, AP and clay content on the basis of the PCA results. The soil quality index (SQI) was calculated using Integrated Quality Index (IQI) equation. Landslide affected sites L1, L2, L3 and L4 and control site had mean SQI scores of 0.136, 0.279, 0.447, 0.604 and 0.882, respectively.

The results have demonstrated that the control site had much better soil quality in comparison to the landslide affected sites because of its better nutrients content and better physical characteristics. The results have also shown that the soil quality tends to increase with the age of landslide, but the soil quality has not reached to the pre-disturbance level in a period of 26 years. The SQI shows the variations in landslide affected sites which could be used to detect variations in soils of disturbed areas. The results will also provide crucial information for evaluating the consequences, designing, and implementing restoration strategies.
Increased Drought Intensity Reduces Release of Plant Carbon into Dissolved Organic Carbon Pool
Authors: Orme Alice , Lange Markus , Schroeter Simon Andreas , Wicke Marcus , Pohnert Georg , Gleixner Gerd
Published: March 2022

Drought is an ever-increasing threat; its negative effects on ecosystems and their functioning directly impact our food security. It is therefore critical to understand the mechanisms that affect drought resilience of ecosystems. Many ecosystem functions depend on plant-soil interactions and are mediated by dissolved organic molecules, which are then recorded in the dissolved organic carbon (DOC) that leaches from plants and soils. In particular, DOC properties during and after rewetting can reveal if and how ecosystems are affected by drought. We therefore investigated the concentration of DOC in four different plant communities on sandy soils in Germany over three years that differed in drought intensity, including the extreme 2018 drought. We also analysed the molecular composition of DOC using ultrahigh-resolution mass spectrometry to identify the carbon sources during the rewetting period. A linear mixed effect model revealed that drought intensity significantly affected DOC concentration. DOC concentration in soil leachate was slightly increased following medium drought intensity, but was significantly reduced following high drought intensity. This suggests that medium intensity drought may stimulate DOC release, however, high intensity drought reduces DOC release. Molecular composition analysis of the DOC present during the rewetting period revealed an initial release of plant-derived carbon followed by an increase in soil organic matter-like compounds. Our findings indicate that the initial release of plant-derived carbon into soil leachate might be crucial for the ability of ecosystems to quickly recover from drought. High intensity drought may interrupt plant functioning to the point of preventing the accumulation and subsequent release of plant-derived carbon during drought, and therefore hamper ecosystem recovery. This suggests the presence of tipping points with respect to the ability of ecosystems to recover from drought. As such, monitoring DOC concentrations could lead to better assessements of the drought resilience of ecosystems.
Seafloor expression of the deep structure during initiation of transtensional fault systems, as seen in the North-South fault system of the Alboran Sea, SE Iberia.
Authors: Canari Bordoy Ariadna , Perea Hector , Martínez - Loriente Sara , Gràcia Eulàlia , Fernández - Blanco David , Llopart Jaume
Published: March 2022

How fault segments grow and connect in regions with moderate to high seismic activity is key to assess associated hazards. Earthquakes may affect populated areas and can trigger tsunamis that threaten coastal areas and affect marine infrastructures. Regions accommodating relatively slow tectonic deformation may still enclose active fault systems capable of generating moderate to large magnitude earthquakes, albeit at long recurrence intervals (103 to 104 years). Although the Alboran Sea is currently characterised by slow tectonic deformation and by earthquakes of low to moderate magnitude, large historical and instrumental events have also occurred (i.e., the Almeria 1522 IEMS98 VIII-IX or the Al-Idrissi 2016 Mw 6.4 earthquakes). This Neogene basin located in the westernmost Mediterranean Sea absorbs most of the convergence between the Eurasian and Nubian plates (3 - 5 mm/year) by means of four tectonic-scale fault systems: the Carboneras and Al-Idrissi left-lateral strike-slip faults, the Yusuf right-lateral strike-slip fault and the Alboran Ridge thrust.

Our study characterises the North-South fault system on the northern Alboran Sea to better understand the kinematics of the region on a larger scale. This system is proposed as the northern termination of the Al-Idrissi fault, and it may be presently evolving due to the transtensional stress field that affects the area. The first step to characterise the fault system has been to elaborate a detailed geomorphological map of the area to describe the identified scarps, their distribution, and structural relations. To achieve this, we have used very high-resolution bathymetric data (1x1 m pixel resolution) acquired with an autonomous underwater vehicle. The bathymetry shows several fault scarps striking N-S, resulting in horst and graben systems. The second step has involved the interpretation of high-resolution multichannel airgun and sparker seismic profiles running across the N-S faults. The integration of this dataset allows us to relate the morphological scarps with different normal faults interpreted in the seismic profiles. These faults cut the post-Messinian seismostratigraphic units (last 5.3 Ma) up to the seafloor, which supports that the fault system is currently active. Finally, the high segmentation of the North-South fault system and its small accumulated fault displacements supports it is in its initial stage of evolution.
A4alerts: Design and implementation of a mobile device app for a community-based Site-Specific Early Warning System (SS-EWS) in Catalonia, Spain
Authors: Meléndez-Landaverde Erika , Sempere-Torres Daniel , Berenguer Marc
Published: March 2022

Significant progress has been made in the capability and accuracy of forecasting extreme rainfall events and their associated impacts. However, damages remain high and will continue to rise unless immediate actions are taken to support communities in decreasing the impacts of upcoming extreme weather-induced events. In this context, innovative technological tools can help to quickly disseminate relevant impact-based warning information and trigger appropriate self-protection actions based on the local vulnerability and exposure for effective disaster risk reduction.  For this purpose, a mobile app named “A4alerts” has been designed in this research.  

The tailor-based A4alerts app communicates impact-based warnings for vulnerable locations within high-risk areas (SSWs) generated by a community-based site-specific early warning system (SS-EWS). Based on a participatory approach with community stakeholders, the SS-EWS blends meteorological information coming from radar-based nowcasting, numerical weather prediction models and local risk information to trigger the SSWs disseminated via the A4alerts app. In addition to communicating the active warnings in the area, the app lists the available actions recommended to mitigate and reduce the potential local impacts for each warning level based on pre-approved self-protection plans. Furthermore, users can send geotagged photos and information through the A4alerts app to validate the events and their impacts.

The A4alerts app has been implemented and tested for selected vulnerable points in cities across Catalonia, Spain. Its capabilities and design have been improved following an iterative approach with end-users to incorporate their feedback and suggestions. Finally, the configuration of the A4alerts app allows it to be easily implemented and exported to new cities to help communities be prepared in times of climate emergency.
Detecting H2 degassing events related to serpentinization in Oman
Authors: Aiken John , Sohn Robert A. , Kelemen Peter B. , Renard François , Jamtveit Bjørn
Published: March 2022

Peridotite alteration via serpentinization has been identified as a major potential sink of man-made carbon. Peridotite serpentinization provides a geochemical pathway to store CO2 as a solid, and releases natural hydrogen as a byproduct. Given the large quantities of peridotite available in oceanic environments, serpentinization could serve as a major component in mitigating man-made climate change. “Reaction driven cracking” has been proposed as an attractive mechanism to explain how peridotite is fully serpentinized.  In this process, when the peridotite alters and becomes a serpentinite, the volume of the rock grows producing stress on the surrounding rock. This process produces new fractures that allow water to enter new areas within the rock thus promoting new serpentinization. Cracking events due to this fracturing process being driven by peridotite alteration have never been detected in the environment (e.g., seismic data). As part of the Oman Drilling Project, a network of 12 hydrophones was deployed in two boreholes drilled in Oman over a period of nine months. This network was designed to detect the microseismic cracking events associated with reaction driving cracking. Surprisingly, it has served as an excellent detector of natural hydrogen degassing events. Hydrogen is a byproduct of the geochemical serpentinization process. These intermittent events come in short “spurts” where periods of quiescence alternate with short periods where many bubbles come out all at once. This poster presents evidence of hydrogen degassing events related to active serpentinization in Oman. We use the results to provide estimates of hydrogen released during the period of hydrophone deployment based on estimated bubble volumes.
The last deglaciation of the Eurasian ice sheet (21,000 - 8,000 yr BP): a sensitivity study to PMIP3/PMIP4 coupled atmosphere-ocean models outputs
Authors: van Aalderen Victor , Charbit Sylvie , Dumas Christophe , Quiquet Aurélien
Published: March 2022

Rapid sea-level rise, due to melting and destabilization of present-day ice sheets will likely have important consequences on human societies. Observations provide evidences of increased mass loss in the West Antarctic Ice Sheet (WAIS) over the recent decades, partly due to ocean warming. Despite improvements in both climate and ice-sheet models, there are still significant uncertainties about the future of West Antarctica, due, in part, to our misunderstanding of the process responsible for the marine ice sheet evolution. Paleoclimate studies provide important information on ice-sheet collapse in a warming world.

Our study is based on the Eurasian Ice Sheet (EIS) complex, including the British Island Ice Sheet (BIIS), the Fennoscandian Ice Sheet (FIS) and the Barents Kara Ice Sheet (BKIS). Because large parts of both the BKIS and the WAIS are marine-based, the BKIS at the LGM can be considered as a potential analogue to the WAIS.

To improve our understanding of the mechanisms responsible for the EIS retreat, we performed transient simulations of the last EIS deglaciation (21 000 – 8 000 yr BP) with the GRISLI ice sheet model forced by 5 PMIP3/PMIP4 models, and two transients GCM models, TRACE21K and iLOVECLIM. Our main goal is to investigate the sensitivity of the EIS grounding line retreat to climate forcing, sea-level rise and glaciological processes with a focus on the BKIS evolution during the deglaciation and the behaviour of the large Bjornoyrenna ice stream.  
A database of crystal-bearing magmas for the calibration of a rheological model
Authors: Frontoni Alessandro , Costa Antonio , Vona Alessandro , Romano Claudia
Published: March 2022

In this work, we present a novel rheological database including most of the existing data relevant for crystal-bearing magmas collected from the scientific literature, covering the entire range of natural volcanic conditions, in terms of crystal content (1-80%), crystal shape (aspect ratio R from 1 to 13), and strain rate (between 10-7 and 102 s-1).

Datasets were collected and discerned as a function of the information which we considered necessary for building a general systematic model describing relative viscosity of crystal-bearing magmas, such as the apparent and melt viscosity, the crystal concentration, crystal shape, and the strain rate. The selected dataset was then used for modelling the relative viscosity of a liquid-solid mixture having different concentrations of particles with different R, subjected to different strain rates. The proposed model is based on a generalization of the four parameters semi-empirical formula, proposed by Costa et al. (2009). A new model was calibrated for the novel collected database, allowing us to quantitatively describe the rheological behaviour of crystal-bearing magmatic systems.
Impact of wildfires on long-term erosion rates: comparing connectivity indices and landscape evolution modelling
Authors: Parente Joana , Nunes João Pedro , Baartman Jantiene , Föllmi Dante
Published: March 2022

Mediterranean countries, such as Portugal, are often associated with soil erosion and land degradation risks, which cause an increasing pressure on ecosystem services. In most of these countries, wildfires occur during the summer, and are usually followed by heavy rainfall events which, in combination with steep slopes and in some cases lack of vegetation cover, can easily provoke runoff and erosion. This is generally due to three main erosion contribution processes: i) a reduction of interception and evapotranspiration; ii) a decrease in infiltration and soil water retention; iii) a reduction in obstacles. For the latter, burnt areas tend to increase water and sediment connectivity by changing vegetation cover and physico-chemical soil properties. Sediment connectivity in a specific catchment is affected by its size, land cover and land use, and the distribution of hillslopes and floodplains (Borselli et al., 2008). Taking this in mind, this study aims to assess post-fire soil erosion patterns at the decadal scale comparing different approaches. The methodology comprises i) a process-based model that is able to investigate long-term and large-scale spatial landscape evolution, LAPSUS; (ii) an index that represents a connectivity assessment based on local landscape information, the Borselli Index of Connectivity (IC); and (iii) an index that represents the sediment eroded that actually reaches the stream based on local landscape information, combining the IC with the Revised Universal Soil Loss Equation (RUSLE) model. Results include a comparison between the approaches used in the context of specific fire events between 1979 and 2020 for the Agueda watershed in central Portugal. The authors believe that assessing the spatial-temporal evolution of connectivity in the actual landscape with the right tool is extremely important to estimate the probability that a given part of the landscape transfers its sediments elsewhere in the catchment.

References

Borselli, L., Cassi, P., Torri, D., 2008. Prolegomena to sediment and flow connectivity in the landscape: A GIS and field numerical assessment. Catena 75, 268–277. https://doi.org/10.1016/j.catena.2008.07.006 

Acknowledges

This work was produced in the framework of project FRISCO - managing Fire-induced RISks of water quality Contamination (PCIF/MPG/0044/2018), and funding attributed to the CE3C research center (UIDB/00329/2020). 
Past plants to past vegetation and climate: the use of phytolith analysis in Stone Age deposits in South Africa
Authors: Murungi May
Published: March 2022

South Africa today represents the epitome of human origins research on the continent. However, South Africa generally lacks long continuous lake sediment records and long-term continental response to climate change and its linkages to the oceans, ice sheets and human evolution has been extrapolated from marine cores off its coasts. This has resulted in the dependence on archaeological deposits to infer past climates and environments despite their shortcomings. To this end, the application of phytolith analysis (plant silica) to understand early hunter-gatherer plant use, their way of life and their environments in terms of vegetation and climate is taking shape at various archaeological sites in South Africa. Phytoliths are hard and resistant to mechanical and chemical stress and can survive in soils for thousands of years making them an important tool for palaeoenvironmental reconstructions. Here, I discuss phytolith data from three key Middle Stone Age sites in the Summer Rainfall Region (Sibudu cave, Bushman rockshelter and Umhlatuzana rockshelter) that preserve phytoliths in their sediment deposits and show how it provides new or complimentary and supplementary data to existing proxies at these sites and its limitations in reconstructing past vegetation and in turn inferring past climates.
Evaluating the Impact of Topography on Initiation of Nor’westers over Eastern India
Authors: Sahu Rajesh Kumar , Singh Kuvar Satya , Nayak Hara Prasad , Tyagi Bhishma
Published: March 2022

Pre-monsoon thunderstorms are a common source of natural destruction over eastern India, commonly known as Nor'westors. Meteorologists studied these Nor'westers for more than a century over India. Various studies highlighted that the Chota Nagpur plateau, situated in Jharkhand state, acts as a triggering source for initiating these thunderstorms. The present study attempts to evaluate the topographical variations of the Chota Nagpur plateau for initiating the Nor'westors. The current research simulated ten thunderstorm events over the Kolkata region, West Bengal, by changing the Chota Nagpur plateau's topography (increasing and decreasing along with natural topography). The study uses the Weather Research and Forecasting model (WRF ARW 3.9.1) with a triple nested domain. The innermost domain has a resolution of 3 km across eastern India. The simulated model variables are validated against vertical profiles and surface observations of point locations obtained from the India Meteorological Department's radiosonde and automatic weather station data sets. The model simulations significantly capture the observational (surface and vertical profile) characteristics. Thermodynamic indices obtained from simulations revealed that the plateau's changed (increased/decreased) topography alters the values considerably below/above thresholds for thunderstorms over the region.

Keywords: Thunderstorms; Topography; Numerical Simulation; Thermodynamic Indices
Interannual variability in the ocean CO2 uptake along the West Antarctic Peninsula: A decade of year-round observations 
Authors: Droste Elise , Bakker Dorothee , Venables Hugh , Hoppema Mario , Dall'Olmo Giorgio , Queste Bastien
Published: March 2022

The West Antarctic Peninsula (WAP) has warmed rapidly due to global climate change and there is large interannual variability in winter conditions, especially sea ice duration. Sea ice driven changes in the water column stability and marine biogeochemistry are impacting the CO2 uptake in this highly productive region. This work extends the Rothera Oceanographic and Biological Time Series (RaTS) to a decade of year-round observations of surface water carbonate chemistry (2010-2020). This spans considerable sea ice variability, allowing assessment of the air/ice/ocean system across a wide range of conditions, including low sea ice cover as is predicted for the region. It includes rare winter-time data that show an unbiased view of annual carbonate processes and how they might be seasonally interconnected and coupled to sea ice dynamics. Even though the coastal region at Marguerite Bay is a net sink of CO2, the time series is characterised by strong seasonal variability, indicating that this coastal region is a source of CO2 to the atmosphere during the austral winter and a strong CO2 sink in the summer. Additionally, we see differences in the net CO2 uptake between different years. Net annual CO2 uptake increased between 2014 and 2017 compared to previous years due to longer durations of heavier sea ice cover. Annual CO2 uptake decreased again between 2017 and 2020, which are years associated to lower sea ice concentration and shorter duration of sea ice cover. We focus on the interannual differences in sea ice concentration and extent and how they are linked to differences in the water column structure, biogeochemical properties, and air-sea CO2 exchange.
Development of a permittivity sensor for melting probes to explore terrestrial and extraterrestrial cryospheres
Authors: Becker Fabian , Friend Pia , Helbing Klaus
Published: March 2022

We will present the design of a permittivity sensor that can be attached to a melting probe and measure the respective ice properties during the melting process, yielding in a comprehensive permittivity profile. Melting probes were already successfully applied in terrestrial cryospheres, such as alpine glaciers and Antarctica. Further applications to cross the ice shield on Dome C in Antarctica or even on icy moons in the outer solar system, such as Europa, are already planned e.g. within the TRIPLE project line funded by the German aerospace center. A sensor measuring the permittivity of the surrounding ice in situ during melting could provide valuable data about the ice properties. The respective density of the ice is correlated with the permittivity, or volcanic ash layers can be identified through permittivity measurements. Another usage of the data could be to correct distance measurements from radar travel times within the ice.

The sensor is designed to operate in the frequency range of 0.1 - 1.5 GHz and works in the range of the near field, which is defined to be within one wavelength, corresponding to the frequency. The concept of this sensor is based on an open coaxial probe, which is connected to the medium of interest. The measurement principle and calibration techniques, as well as first lab measurement results of ice and other materials will be presented. A comprehensive data set on effects of porosity, salinity and impurities of lab-manufactured ice samples on the permittivity will also be given. These data will help to interpret the taken permittivity profiles of glaciers on further missions.

We will also show how the device can be integrated into a melting probe, such as the TRIPLE melting probe. One major challenge is to ensure good contact to the ice during measurement. The diameter of a melting hole often results to be several cm larger in diameter than the melting probe itself. A mechanism that extends the sensors of the melting probe and press it onto the ice for measurements is being developed. 
Flood risk assessment framework for Himalayan river basin
Authors: Dhote Pankaj R. , Moothedan Antony Joh , Thakur Praveen K. , Agarwal Ankit
Published: March 2022

Increasing rate of flash-floods in Himalayan river basin causes immediate damage to human lives, daily living and infrastructure. The present work proposed flood risk assessment framework by blending the hydrodynamic modelling outputs and risk evaluation concepts. The different notions of risk as in hazard, vulnerability and exposure were evaluated over flood-prone Beas river with focus at Bhuntar, Kullu and Manali. The hydrodynamic model (MIKE 11) was established for 56 km river stretch right from Manali to Bhuntar. The flood depth and flow velocity outputs from the calibrated and validated hydrodynamic model were used for the estimation of flood hazard rating. Vulnerability maps were generated using depth-damage curves prepared by Joint Research Centre, EU, for each exposure of agriculture, settlement and roads. The 100 year return period flood risk maps were prepared and analysed for all the three towns. Key interviews and community focus group discussions were held further to strengthen, compare and verify the achieved outcomes. For a 100 year return period flood risk assessment, a total of 0.054 km2, 0.226 km2 and 0.334 km2 area was flooded and extreme flood risk zones were identified with 4.7%, 6.8%, and 10.9% area of the total inundated area at the settlement regions of towns of Manali, Kullu and Bhuntar, respectively. The area on right bank of the river was inundated severely and got classified into extreme flood risk zones. The major settlements at all the towns under consideration are at the right bank due to relatively flat, low lying terrain leading to the dire risk. The outcome of the work can assist disaster managers and local administrations for flood disaster planning in advance, thus reducing human and economic loss.  Further, flood risk map could serve as catastrophic product to define flood insurance rate for various exposures in floodplain.

Keywords: Flood Risk Assessment, MIKE11, Hazard, Vulnerability, Hydrodynamic Modelling
Quantifying the effects of employing multiple disaster risk reduction strategies in a coastal flood risk context on the global scale
Authors: Mortensen Eric , Tiggeloven Timothy , Haer Toon , Eilander Dirk , Muis Sanne , Sperna Weiland Frederiek , le Bars Dewi , Aerts Jeroen , de Ruiter Marleen , Ward Philip
Published: March 2022

Coastal flood risk is a major global challenge facing current and future generations. Indeed, this risk is expected to increase over the next several decades due to the changing climate, increased urbanization within flood-prone areas, loss of natural coastal defenses, and underground resource extraction, among other global factors. A number of risk reduction strategies have been posited as methods of mitigating the deleterious impacts of coastal flooding and investigated thoroughly through several existing small-scale applications around the world.

On the global scale, however, efforts to model the effects of such risk reduction strategies in the future are rather limited. Most global modeling efforts that have been undertaken typically examine the potential risk reductions of structural measures (e.g., dykes and levees). And while some initial progress has been made in recent years on assessing alternative risk reduction strategies, the majority of this work still looks to quantify the effects of individual strategies alone. In reality, the hybridization of risk reduction strategies may be the most cost effective or environmentally feasible pathway forward for different segments of society.

We look to quantify the risk reductions expected from employing multiple strategies at once. Within the same global flood risk modeling framework, we model the dry-proofing of urban assets, restriction of future development within flood-prone zones, and conservation of foreshore vegetation. In addition to modeling these strategies individually, we determine what risk reductions are possible when they are hybridized, both with each other and also structural measures. By using a disaster risk framework – risk defined as a product of hazard, exposure, and vulnerability – and a benefit-cost analysis that measures financial and human impacts of each strategy, we determine expected levels of risk reduction for different regions of the world. These results are available for various points in the future under various representative concentration pathway and shared socioeconomic pathway combinations. Further, we demonstrate which (combinations of) strategies may be able to achieve similar levels of overall risk reduction that would be anticipated with solely structural measures. This work not only demonstrates how the envelope of potential options can be expanded for decision makers addressing coastal flood risk, but also can be used as the foundation of future risk flood reduction assessments that incorporate more options than those examined here.
Story continued: The Lagged Rejuvenation Phenomenon at the Krycklan catchment - 49 new samples reveal groundwater flow patterns and hydrological connectivity 
Authors: Kolbe Tamara , Marçais Jean , Vergnaud Virginie , Yvard Barbara , Bishop Kevin
Published: March 2022

The distribution of groundwater ages in aquifers is a key indicator for flow processes, solute transport and biogeochemical reactions. A lagged rejuvenation of groundwater ages has been observed at a 0.47 km2 subcatchment of the Krycklan catchment in 20171. Chlorofluorocarbons (CFCs) were measured in 9 wells at different depths located close to the stream and revealed an overall representative age stratification for the subcatchment. Immediately below the water table at 1-2 meters depth, groundwater was already 30 years old. This lag in rejuvenation was successfully modeled on the assumption that it was caused by seepage flow of groundwater in the subsurface discharge zone that evolves along the interface between two soil types with different hydraulic permeability. The comparison of the observed groundwater age stratification with a simple analytical approximation shows that the lag in rejuvenation is an indicator for the extent of the subsurface discharge zone and the vertical gradient for the overall aquifer recharge.

To test this hypothesis a second sampling campaign in 2021 was performed. CFCs were measured in 49 sampling locations at different depths and distances to the stream within the subcatchment and neighboring subcatchment.  CFC-based groundwater ages show the extent of the subsurface discharge zone and reveal groundwater flow patterns. This study provides further information on the hydrological connectivity of groundwater in the hydrological cycle. 

 

References:

1Kolbe, T, Marçais, J, de Dreuzy, J-R, Labasque, T, Bishop, K. Lagged rejuvenation of groundwater indicates internal flow structures and hydrological connectivity. Hydrological Processes. 2020; 34: 2176– 2189. https://doi.org/10.1002/hyp.13753

 
The Changbaishan Millennium eruption tephra recorded in the Yueliangwan peatland, northeast China
Authors: Zhang Mingming
Published: March 2022

Changbaishan Tianchi volcano is one of the most famous active volcanoes in Northeast Asia. Its Millennium eruption (ME, 946-947 CE) is considered to be one of the largest explosive eruptions over the past 2000 years, which had produced widely distributed tephra layer across Northeast Asia. However, little attention has been paid to the tephra buried in peatlands around this volcano. Here we present petrographic, geochemical and AMS14C data of the volcanic glasses within a new discovered macro-tephra layer buried in the Yueliangwan peatland, northeast China. The results suggest that buried tephra was the product of Changbaishan Millennium eruption. The eruptive sequence of the ME included comendite eruption and trachyte eruption from bottom to top. Tectonic background analyses reveal that Changbaishan Tianchi volcano fields belong to the anorogenic within plate back-arc extensional tectonic environments. Eruptive and sedimentary processes of the buried tephra were postulated as follows: a large amount of volcanic glasses formed through the eruption of trachyte magma that had high contents of rare earth elements (REE) and trace elements (TE). Then, fine grained volcanic glasses were sprayed into the atmosphere and transported to the Yueliangwan areas. The volcanic glasses deposited and formed airborne pumice layer. This buried tephra layer would act as a key isochronous marker horizon for the chronological framework in a range of sedimentary contexts across Northeast Asia. And it provides accurate eruptive sequence of Changbaishan Millennium eruption. This study would attract more attentions on the buried tephra in peatlands around active volcanoes, which would be of significance for the reconstructions of volcanic eruption history.
QUARTETnary - The card game about the geological time scale
Authors: van Zelst Iris , Perez-Diaz Lucia
Published: March 2022

QUARTETnary is an educational card game about the geological time scale. Playable by anyone from 9 to 90, the game play follows that of the classic card game ‘quartets’, where players aim to collect sets of four cards belonging to a specific group (in this case, a certain geological time period). At the end of the game, the player with the most complete geological time line (i.e., the most quartets) wins the game! 

QUARTETnary consists of 15 different card quartets, each corresponding to a different geological eon, era, or period, starting in the Hadean and ending in the Quaternary. For each quartet, the cards represent key events, animals, or processes. For example, the Hadean consists of 1) the formation of the Moon; 2) Earth’s magma ocean; 3) the layered Earth; and 4) the first occurrence of liquid water on the planet. The cards specifically focus on geodynamic processes (i.e., the formation of Gondwanaland, Pangea, the Himalayas) and evolutionary developments (i.e., bacteria, land plants, mammals etc.) as well as major global events such as mass extinctions and the Cambrian explosion of life. They are illustrated in accordance with the official colour scheme set by the International Commission on Stratigraphy to ensure easy comparison with the official geological time scale.

Here, we present the first illustrated cards of QUARTETnary and parts of the accompanying booklet that provides more information on each of the time periods and the reasons for the inclusion of specific events on each of the cards. 

In addition, we discuss the launch of our website and twitter account in October 2021 in preparation of a kickstarter campaign to fund the production of the game within the next two years. We review how we prepared our social media campaign and show the resulting online engagement, plus illustrative reactions from the geosciences community. 
Scotland’s national saltmarsh carbon resources: an assessment of organic carbon stocks and burial rates
Authors: Miller Lucy , Smeaton Craig , Austin William
Published: March 2022

Scotland’s saltmarshes bury and store organic carbon (OC) for extensive periods of time, and thus, could potentially contribute as a natural solution to combat climate change. Recent studies have calculated that the top 10cm of Scottish saltmarshes hold approximately 367,888 ± 102,278 tonnes of OC [1]. Despite this new understanding of the surficial OC stock, the rate at which OC is buried is largely unknown. This study focusses on 10 contrasting saltmarshes around Scotland and presents an in-depth analysis of their total organic carbon (TOC) stocks and burial rates. Chronology data (provided by radioisotope analysis) provides information on the age of saltmarsh soils, as well as OC accumulation rates. Additionally, stable isotope analysis (δ13C and δ15N) allows improved understanding of carbon sources. Sediment carbon analysis, sediment descriptions and vegetation surveys were used to generate TOC stocks for each saltmarsh. The results showed that between 8,253 and 91,028 tonnes of OC is stored in these contrasting saltmarshes and OC burial rates range between 29.1 and 142.5 gC m-2 yr-1. This work highlights the role that saltmarshes play as a natural component in coastal climate mitigation and their wider significance as blue carbon environments contributing to Scotland’s natural capital.

[1] Austin, W., Smeaton, C., Riegel, S., Ruranska, P., Miller, L (2021). Blue carbon stock in Scottish saltmarsh soils. Scottish Marine and Freshwater Science, 12 (13)