bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation of the Martian Highlands during its formation.
Authors: Bonnet Gibet Valentin , Michaut Chloé , Bodin Thomas , Wieczorek Mark , Dubuffet Fabien
Published: February 2023

The Martian crust is made up of sedimentary and volcanic rocks that are mainly mafic in composition. Nevertheless, orbital and in-situ observations have revealed the presence of felsic rocks (Payré et al, 2022), all located in the southern hemisphere, where the crust is thicker. These rocks likely formed by differentiation of a basic protolith. On Earth, this process occurs at plate boundaries and is linked to active plate tectonics. But on Mars, we have no evidence of active or ancient plate tectonics.On one-plate planets, there exists a positive feedback mechanism on crustal growth: the crust being enriched in heat-producing elements, the lithosphere is hotter and thinner where the crust is thicker, which implies a larger melt fraction at depth and therefore a larger extraction rate and a larger crustal thickening where the crust is thicker. We proposed that this mechanism could have been at the origin of the Martian dichotomy (Bonnet Gibet et al, 2022). This mechanism further implies that regions of thicker crusts, characterized by a larger amount of heat sources, a thinner lithosphere and an increased magmatism, are also marked by higher temperatures. Here we investigate whether crustal temperatures in regions of thick crust may be maintained above the basalt solidus temperature during crust construction, which would allow for the formation of partially molten zones in the crust and hence differentiated rocks by extraction of the melt enriched in water and silica. In this scenario, felsic rock formation would be concomitant to crustal construction and dichotomy formation on Mars.We use a bi-hemispheric parameterized thermal evolution model with a well-mixed mantle topped by two different lithospheres (North and South) and we account for crustal extraction and magmatism in these two hemispheres. We formulate a Bayesian inverse problem in order to estimate the possible scenarios of thermal evolution that are compatible with constraints on crustal thickness and dichotomy amplitude derived from the InSight NASA mission. The solution is represented by a probability distribution representing the distribution on the model parameters and evolution scenarios. This distribution is sampled with a Markov chain Monte Carlo algorithm, and shows that a non-negligible range of scenarios allows for partial melting at the base of the Southern crust below the Highlands during the first Gyr of Mars' evolution. On the contrary, partial melting of the base of the northern crust is insignificant. Models that fit InSight constraints and allow for differentiation of a fraction of the Southern crust point to a relatively low reference viscosity (~1020 Pa.s) that can be explained by a wet mantle at the time of crust extraction.
The EMSO-E2M3A Southern Adriatic Regional Facility: Interconnectedness of a variety ofprocesses at different spatial and temporal scales, their interaction and recurrence.
Authors: Cardin Vanessa , de Luca Lopes de Amorim Felipe , Ursella Laura , Wirth Achim
Published: February 2023

The EMSO-E2M3A South Adriatic Regional Facility provides high-frequency (every hour) temperature and salinity data from 2006 to 2019 along the water column from 150 dbar to the seafloor. Their study reveals processes on different temporal scales, i.e. daily, seasonal, intra-annual and inter-annual, as well as their recurrence (seasonal or not) and climatic trends. The area is characterized by cyclonic circulation, which preconditions deep convection processes that involve both atmospheric and ocean dynamics, forming new, dense and oxygen-rich waters. There are intermittent influxes of high salinity water from the Ionian Sea, that favor salt fingering, and dense overflows from the northern Adriatic. The region is also subject to strong surface cooling. Data collected by the E2M3A observatory allows monitoring of variability on short scales related to convection and submesoscale processes. On an intermediate time scale, changes in basin circulation are monitored, and on a larger time scale, climate variability in the area is monitored. The various processes interact in a nonlinear manner, highlighting the importance of high-frequency measurements of rapid processes and their interaction with and correction of slowly varying properties on a longer time scale.From ADCP data, the signature of zooplankton migration at the surface/intermediate layer is determined to be enhanced by convection-induced mixing. On the monthly scale, thermohaline variability increases substantially due to oscillations triggered by a combination of factors that include salinity intrusion into the intermediate layer, strong heat loss at the surface, and variability in vorticity during the winter months. The lower layer of the pit has been characterized by a slightly positive trend in temperature and salinity over the last decade, interrupted only by the inflow of dense water from the northern Adriatic Sea cascading through the Canyon of Bari.
Understanding climate drivers of drought and fire multi-hazards in Indonesian Borneo using climate model and seasonal hindcast ensembles
Authors: Lam Timothy , Catto Jennifer , Barciela Rosa , Harper Anna , Challenor Peter , Arribas Alberto
Published: February 2023

Fires occurring over the peatlands in Indonesian Borneo accompanied by droughts have posed devastating impacts on human health, livelihoods, economy and the natural environment, and their prevention requires a comprehensive understanding of climate-associated risk. We want to strengthen the possibility of early warning triggers of drought, which is a strong predictor of the prevalence of fires, and evaluate the climate risk relevant to the formulation of long-term policies to eliminate fires. Although it is widely known that the droughts are often associated with El Niño events, the onset process of El Niño and thus the drought precursors and their possible changes under the future climate are not clearly understood. Here we use a causal network approach to quantify the strength of teleconnections to droughts at a seasonal timescale shown in (1) observational and reanalysis data (2) CMIP6 models and (3) seasonal hindcasts. We consider two drivers of JJA droughts identified through literature review and causal analysis, namely Niño 3.4 SST in JJA (abbreviated as ENSO) and SST anomaly over the eastern North Pacific to the east of the Hawaiian Islands (abbreviated as Pacific SST) in MAM. The observational and reanalysis data proves that the droughts are strongly linked to ENSO variability, with drier years corresponding to El Niño conditions, and droughts can be predicted with a lead time of three months based on their associations with Pacific SST, with higher SST preceding drier conditions. We find that some CMIP6 models are showing unrealistic amounts of JJA rainfall and underestimate drought risks in Indonesian Borneo and their teleconnections, owing to the underestimation of ENSO amplitude and overestimation of local convections. Under the SSP585 scenario, the CMIP6 multi-model ensembles show significant increase in both the maximum number of consecutive dry days in the Indonesian Borneo region in JJA (p = 0.006) and its linear association with Pacific SST in MAM (p = 0.001) from year 2061 – 2100 compared with the historical baseline. On the other hand, seasonal hindcast models are (1) overestimating the variability of maximum number of consecutive dry days, (2) showing varied skills in simulating the mean rainfall and drought indicators, and (3) underestimating the teleconnections to Borneo droughts, making it difficult to assess the likelihood of unprecedented drought and fire risk under El Niño conditions. Our study agrees with previous studies regarding the limited skill of fire risk prediction by state-of-the-art seasonal forecasting models, with their shortfalls caused by a lack of proper representation of relevant teleconnections.
The Dynamical Background to the 2022 Asian Summer Monsoon Chemical and Climate Impacts Project (ACCLIP)
Authors: Newman Paul A. , Pan Laura , Elliot Atlas , William Randel , Thornberry Troy , Toon Owen Brian , Ueyama Rei , Lait Leslie , Nash Eric
Published: February 2023

The Asian summer monsoon Chemical and Climate Impact Project (ACCLIP) used the NSF/NCAR Gulfstream V (GV) research aircraft, the NASA WB-57f research aircraft, the Korean NARA King Air, and a broad set of balloon launches to investigate atmospheric processes that influence ozone depletion and climate in the Korea/Japan region.  The WB-57 and NSF GV part of the field campaign was flown from Osan Air Base, Republic of Korea during the July-August 2022 period.This presentation will show some of the dynamical and transport aspects of the Asian summer monsoon anti-cyclone (ASMA) during the summer of 2022. In particular, the strength and flow aspects of the ASMA will be illustrated and shown in the context of an ASMA MERRA-2 climatology. Flight overviews against this flow field will be compared against detrainment events from the ASMA from Asia into the Pacific Ocean. Flight profiles will also show how ACCLIP made extensive sampling of the ASMA’s eastern flank – mapping of the vertical and horizontal structure in the upper troposphere and lower stratosphere.
Observational Assessment of Changes in Earth’s Energy Imbalance Since 2
Authors: Loeb Norman , Thorsen Tyler , Ham Sueng-Hee , Rose Fred , Kato Seiji
Published: February 2023

Observations from the Clouds and the Earth’s Radiant Energy System (CERES) show a marked increase in Earth’s energy imbalance (EEI) since 2000. At the same time, we’ve seen marked changes in numerous geophysical variables that influence EEI. While observations alone cannot quantify the anthropogenic and natural contributions to changes in these quantities, they can provide insight into how changes in different components of the climate system have led to the observed EEI trend. Using additional data from MODIS, CALIPSO, Cloudsat, and reanalysis, we find the increase in EEI to be due to decreased reflection by clouds and sea-ice, which cause a pronounced increase absorbed solar radiation (ASR), and a decrease in outgoing longwave radiation (OLR) due to increases in trace gases and water vapor. The ASR increases are largest over the subtropics and mid-latitudes in regions with decreases in low and middle cloud fraction, which likely occur in response to observed increases in sea-surface temperature (SST) in those locations. We diagnose the SST changes by performing an ocean mixed layer energy budget analysis at regional, hemispheric, and global scales using TOA and surface radiation observations from CERES, SST and temperature/humidity fields from ERA-5, and ocean mixed layer depth from ocean reanalysis. This analysis suggests that heating of the mixed layer and the subsequent increase in SST stems from ocean mixing/advection rather than from surface forcing. 
Estimating Spatially Distributed Irrigation Water Requirements for the Lower Mekong River Basin: Present Condition and Climate Change Impacts
Authors: Luo Yuanyuan , Zhu Tingju
Published: February 2023

The Mekong River is the largest transboundary river in Southeast Asia and the main source of water supply for agricultural irrigation in the Lower Mekong River Basin (LMRB), supporting socioeconomic development and the livelihoods of millions of people. Irrigation accounts for more than 70% of water use in the LMRB, and issues of water use and allocation in the basin attract much attention, especially in dry years. However, there is a lack of systematic and up-to-date estimation of irrigation water requirements (IWR) in the LMRB, for historical and climate change conditions, which are essential for water resources planning and management in the basin. We use gridded meteorological and crop land use data to estimate monthly IWR at 5-arc minute resolution in the five LMRB countries, namely Myanmar, Laos, Thailand, Cambodia and Vietnam, using meteorological observations of 1991-2020 and climate projections for 2031-2060 and 2061-2090 by five global climate models under two climate scenarios, SSP126 and SSP585. Crop water productivity and water footprint are also estimated along with IWR. Under historical climate, the total IWR in the LMRB is estimated to be 20.44 billion m3, with Vietnam having the largest share of 9.18 billion m3, followed by Thailand with 7.54 billion m3. IWR concentrates in the dry season of November-April, accounting for 78.4% of annual IWR. Rice is the main water-consuming crop, accounting for 86.7% of total IWR. Relative to historical climate condition, SSP126 generally leads to slightly decreased IWR, whereas SSP585 leads to a large increase in IWR. Crop water productivity of rice is unevenly distributed in the basin, being higher in Vietnam and Laos and lower in Cambodia and Thailand. Green water footprint of rice is about 3.7 times higher than that of blue water footprint, indicating most of rice water consumption is from precipitation. Under SSP126, there is little change in water footprint, however under SSP585 blue water footprint increases significantly, in 2061-2090. This study provides update-to-date and high-resolution IWR estimates which can support water use and allocation dialogue, policy-making and management in the basin.
Effects of increasing horizontal and vertical resolution in Korean Integrated Model (KIM)
Authors: Park Ja-Rin , Kong Hae-Jin , Nam Hyun , Choi Suk-Jin
Published: February 2023

Since the dynamical core of Korean Integrated Model (KIM) was developed in the 1st phase (2011~2019) of KIAPS, we have been aiming to develop a variable resolution prediction system covering short to medium range in the 2nd phase (2020.9~2026). As a first step towards moving to km-scale resolution, we have increased the model resolution from 12 km to 8 km horizontally and 91 to 137 layers vertically. For increasing the resolution horizontally, dynamics core configurations and terrain elevation data were newly set up. For vertically, vertical coordinates of 137 layers followed that of the European Center for Intermediate Forecasting (ECMWF) Integrated Forecasting System (IFS), which has been increased vertical resolution throughout the troposphere and stratosphere comparing to 91 layers.This study discusses the forecast impact of high-resolution KIM in terms of objective verification scores against observations and analyses. The overall conclusion for horizontal high-resolution is that it shows slightly positive in southern hemisphere and mainly neutral for northern hemisphere, but also some negative in tropics. One of distinguished results is increasing horizontal resolution leads to cooling in the temperature in the lower and upper troposphere. The cooling in the lower tropospheric over the tropics seems to come from smaller time step that has to be for smaller dx, which results in enlarged low cloud formation and thus more radiative cooling. In case of the upper troposphere, the cooling results from outgoing long-wave radiative cooling by decreasing hydrometeors in physical response to smaller grid spacing. The increase of vertical resolution had an effect of neutral to slight positive in northern hemisphere but showed significant degradation in tropics. To achieve the consistency and improvement for high-resolution model, it is necessary to understand the physical processes related to time step and horizontal and vertical grid spacing. AcknowledgementOne of the authors, S-J Choi, wishes to acknowledge this study was supported by 2023 New Professor Support Program of Natural Science Research Institute in Gangneung-Wonju National University).
Variation in bright band height during the passage of a typhoon observed with wind profiler radars
Authors: Lee Kyung Hun , Kwon Byung Hyuk , Kim Yujin , Seo Jiwoo , Lee Geon Myeong
Published: February 2023

When snow particles fall and pass through the melting layer, they melt from the surface and change into rain particles. At this time, due to the difference in permittivity between ice and water, reflectivity appears large, and this is called the bright band (BB). Since the BB causes confusion in the precipitation estimation of weather radar, many studies on BB detection have been conducted to improve the quantitative precipitation estimation accuracy of weather radar and the performance of numerical models. Wind profiler radar (WPR) is useful for vertical structure analysis of mesoscale convective systems with excellent temporal and vertical spatial resolution. We analyzed the bright band of Typhoon HAISHEN passing near the Korean Peninsula from 00 UTC on September 06 to 00 UTC on September 07, 2020 by 9-site WPR. As the HAISHEN approached, distinct precipitation patterns and BB were detected with vertical signal to noise ratio and vertical radial velocity. The BB height gradually increased as the typhoon approached, and decreased as it moved away. Therefore, the precipitation converged in the front of the typhoon and originated from a stratiform structure. It is known that the BB height depends on local factors such as ground temperature and topography. However, the BB height in Jeju Island and Chupungnyeong, located on the mountain boundary at about 240 m above sea level, showed 3-4 km and 4-5 km, respectively. In order to understand the structure of a rapidly developing precipitation cell, it is necessary to investigate the dynamic parameters which are optimal to retrieve based on WPR.
Understanding the drivers of pyroCb development over southeast Australia
Authors: Ma Wenyuan , Sharples Jason , Jovanoski Zlatko
Published: February 2023

The incidence and magnitude of extreme wildfires have increased markedly in Australia. In some extreme wildfires, violent pyroconvection can manifest as pyrocumulonimbus clouds (pyroCb), which impact not only the surface but also the atmosphere, leading to dangerous escalation of wildfire risk and severe stratospheric pollution. Climate change could amplify the conditions associated with pyroCb development, so a better understanding of pyroCb drivers and their impact mechanisms is crucial for the prediction and management of pyroCb development.

Previous studies have shown that atmospheric instability, surface fire weather conditions, vegetation type, and topography are important conditions affecting pyroCb development, but the synergy and extent of the contribution of these factors have not been systematically analyzed. Also, previous studies have focused more on individual events or a certain region, lacking analysis of the drivers and occurrence patterns of pyroCb over larger spatial and temporal scales.

This study therefore examined atmospheric, surface weather, topographic and vegetation conditions associated with pyroCbs and standard wildfires occurring over southeast Australia, including the mainland of New South Wales (NSW), Australian Capital Territory (ACT) and Victoria (Vic) from 1980-2020. Then we used logistic models to analyze the relative importance    and regional differences of pyroCb drivers. We found that for the whole southeast Australia, atmospheric variables are the most important pyroCb drivers, followed by topographic and surface weather variables.  Fuel moisture content was found to be the most important among the given surface weather variables. However, the importance of pyroCb drivers varied from region to region. In NSW (including ACT), atmospheric and surface weather variables were more important than topographic variables, while in Vic, topographic variables were the most important, followed by atmospheric and vegetation variables, with surface weather variables having less influence on pyroCb incidence.

The results provide insights that can be drawn upon to better predict the likelihood of pyroCb occurrence and the risk of extreme wildfires over southeastern Australia.
Asymmetric glaciation, divide migration, and postglacial fluvial response times in the Qilian Shan
Authors: Lai Jingtao , Huppert Kimberly
Published: February 2023

Glacial-interglacial cycles have repeatedly perturbed climate and topography in many mid-latitude mountain ranges during the Quaternary. Glacial erosion can move drainage divides and induce fluvial adjustment downstream. Today and in the past, north-facing slopes in the Qilian Shan have accumulated more ice because they receive less solar insolation and more precipitation than south-facing slopes. The larger glaciers that form on north-facing slopes may enhance erosion and drive southward migration of drainage divides, particularly during glacial periods. We combine numerical simulations with topographic analyses to examine the influence of glacial erosion on divide mobility and postglacial landscape response to drainage reorganization. Our analyses suggest that asymmetric glaciation in the Qilian Shan has caused southward migration of the main drainage divide, prompting river channels below the extents of ice on north-facing slopes to become oversteepened relative to their drainage area. This oversteepening should accelerate postglacial fluvial incision, even in this region where topography has not been directly modified by glacial erosion. Numerical modeling suggests this enhanced incision persists for millions of years – much longer than the duration of recent glacial-interglacial cycles – implying a widespread and enduring influence of intermittent glaciations on landscape evolution in mid-latitude mountain ranges during the Quaternary.
The ALOFT mission: a flight campaign for TGF and gamma-ray glow observations over Central America and the Caribbean in July 2023
Authors: Ostgaard Nikolai , Marisaldi Martino , Ullaland Kjetil , Yang Shiming , Hasan Qureshi Bilal , Søndergaard Jens , Mezentsev Andrey , Sarria David , Lehtinen Nikolai , Lang Timothy , Christian Hugh , Quick Mason , Blakeslee Richard , Grove J. Eric , Shy Daniel
Published: February 2023

The Airborne Lighting Observatory for FEGS and TGFs (ALOFT)  is a field campaign focused on observing Terrestrial Gamma-ray Flashes (TGFs) and gamma-ray glows from thunderclouds. ALOFT will be flown on a NASA ER-2 research aircraft, flying at 20 km altitude, and the payload  includes:1) Fly’s Eye GLM Simulator (FEGS), an array of imaging photometers as well as different wavelengths, and electric field change meters.2) Lightning Instrument Package (LIP), giving three component electric field measurements.3) Several gamma-ray detectors covering four orders of magnitude dynamic range in flux as well as the full energy range for TGF/gamma-ray glow detection.ALOFT is scheduled for July 2023, with 50 flight hours based out of Florida.  Flying over thunderstorms in Central America and Caribbean, one of the most active TGF regions on the planet during the most optimal season, the ALOFT campaign will help us to answer the questions:1) How and under what conditions are TGFs produced?2) How extended in space and time are the gamma-ray glows?To answer question 1), the ALOFT campaign will be supported by ground based radio measurements from different locations in Central America and Caribbean.To answer question 2), with realtime downlink of data we will know when the ER-2 encounters gamma-ray glowing thunderclouds, and we will instruct the pilot to have the aircraft perform have repeated overflights over this cloud as long as the glow exists, to answer question 2).  This will also help us understand whether gamma-ray glows and TGFs are interrelated.The full set of observational goals of ALOFT are:1. Observe TGFs in one of the most TGF-intense regions on the planet.2. Observe gamma-ray glows in thunderstorms and their relation to TGFs.3. Perform International Space Station Lightning Imaging Sensor (ISS LIS) and Global Lightning Monitor (GLM) validation using improved suborbital instrumentation (including upgraded FEGS).4. Evaluate new design concepts for next-generation spaceborne lightning mappers.5. If relevant instrumentation is available, make measurements useful to advance convection science from a suborbital platform.In this presentation we will give the status and plans for the ALOFT mission.
Regional Soil Erosion Mapping in Pre-GIS Era: Achievements and implications
Authors: Yang Qinke , Li Rui , Wang Lei , Pang Guowei , Wang Chunmei , Long Yongqing , Yuan Xiaotian
Published: February 2023

Before the wide application of remote sensing and GIS, ie the pre-GIS era, researchers carried out a series of regional (national to global scale) erosion mapping and research, and group of analog map of soil erosion maps. This manuscript summarizes the achievements and shortcomings of these analog maps, and then discuss the implications of them on today's digital soil erosion mapping.From the perspective of geographic information science and digital soil erosion mapping, the main achievements of early soil erosion mapping are summarized in three aspects, including: (1) created the ontology of large regional (national to global) soil erosion research, base on witch, soil erosion can be analysed and control plan can be made. (2) innovatively established the benchmarks and initiation of large regional soil erosion mapping and monitoring; (3) developed a paradigm for for making analog regional soil erosion map. However, the early soil erosion mapping was basically qualitative, static and macro, focusing only on soil and agriculture purpose.The analog soil erosion map has many implications for the current digital soil erosion mapping, including: (1) It always takes the spatial representation of soil erosion as mission for mappers, but cannot be done as a case of application of remote sensing and other technical methods in soil erosion researches. (2) considering the interaction of various erosion processes such as water erosion, wind erosion, and gully erosion, to represent the comprehensive spatial pattern of various types of soil erosion, and to improve the status quo that the quantitative evaluation of erosion rate is only conducted for a certain erosion type. (3) systematically explore and collect legacy data of soil erosion maps, then establish a free available databased of regional soil erosion maps. (4) considering soil erosion as the driving force of the biogeochemical cycling of essential elements (C, N, P, etc) in earth system, overcome the shortcomings of analog erosion mapping, make a try to develop a new paradigm for digital soil erosion mapping.
Antarctic ice-shelf advance driven by anomalous atmospheric and sea-ice circulation
Authors: Christie Frazer , Benham Toby , Batchelor Christine , Rack Wolfgang , Montelli Aleksandr , Dowdeswell Julian
Published: February 2023

The disintegration of the eastern Antarctic Peninsula’s Larsen A and B ice shelves has been attributed to atmosphere and ocean warming, and increased mass losses from the glaciers once restrained by these ice shelves have increased Antarctica’s total contribution to sea-level rise. Abrupt recessions in ice-shelf frontal position presaged the break-up of Larsen A and B, yet, in the ~20 years since these events, documented knowledge of frontal change along the entire ~1,400-km-long eastern Antarctic Peninsula is limited. Here, we show that 85% of the seaward ice-shelf perimeter fringing this coastline underwent uninterrupted advance between the early 2000s and 2019, in contrast to the two previous decades. We attribute this advance to enhanced ocean-wave dampening, ice-shelf buttressing and the absence of sea-surface slope-induced gravitational ice-shelf flow. These phenomena were, in turn, enabled by increased near-shore sea ice driven by a Weddell Sea-wide intensification of cyclonic surface winds around 2002. Collectively, our observations demonstrate that sea-ice change can either safeguard from, or set in motion, the final rifting and calving of even large Antarctic ice shelves.
Model validation in natural hazard forecasting requires an unambiguous hierarchy of uncertainties
Authors: Marzocchi Warner , Jordan Thomas
Published: February 2023

Science is rooted in the concept that a model can be tested against independent observations and rejected when necessary (model validation). However, the problem of model validation becomes formidable when we consider probabilistic models that forecast the evolution of natural "open" systems, which are characterized by the ubiquitous presence of uncertainties of different kind and the impossibility to replicate the process in laboratory.

The purpose of this talk is to clarify the conceptual issues associated with different types of uncertainty and probability in natural hazard analysis, as well as the conditions that make a hazard model testable and thus 'scientific'. We discuss the limits of the classical frequentist and subjective probabilistic frameworks to validate hazard forecasting models and discuss how these difficulties paved the way for some of the strongest criticisms of hazard analysis: arguments that most of natural hazard analyses cannot be validated and are intrinsically 'unscientific', and that the outcome of natural processes in general cannot be accurately predicted by mathematical models (cit).

We show that the proper validation of a forecasting model requires a suitable taxonomy of uncertainty embedded in a unified probabilistic framework. This taxonomy comprises three types of uncertainty: (i) the natural variability of the  system, usually represented as stochastic processes with parameterized distributions (aleatory variability); (ii) the uncertainty in our knowledge of how the system operates and evolves, often represented as subjective probabilities based on expert opinion (epistemic uncertainty); and (iii) the possibility that our forecasts are wrong owing to system processes about which we are completely ignorant and, hence, cannot quantify in terms of probabilities (ontological error). We compare this taxonomy with other conventions for describing uncertainties (i.e., the “likelihood” and “confidence” used by the International Panel of Climate Change), the link with the probability, and their estimation using data, models, and subjective expert opinion. We show that these different uncertainties, and the testability of hazard models, can be unequivocally defined only for a well-defined experimental concept, external to the model under test, that identifies collections of data, observed and not yet observed, judged to be stochastically exchangeable when conditioned on a set of explanatory variables.

These theoretical issues are applicable to a wide range of natural hazards; here, for the sake of example, they will be discussed using real examples in volcanology, tsunami and seismic hazards.
Integration of the WRF Model With Fine-Scale Land Use Data to Simulate Extreme Rainfall Events
Authors: Gaddam Nagaraju , Wadhwa Abhinav , Pentakota Likhitha , Reghunath Gowri , P Mujumdar Pradeep
Published: February 2023

Urbanization results in drastic land alteration in which natural land cover is replaced by impermeable surfaces such as compacted soils, buildings and associated infrastructures. While the impact of urbanization on extreme rainfall is captured in satellite data to a great extent, its signal is frequently less obvious in station-level data. Also, the lack of local meteorological data hinders the development of adequate mitigation measures to reduce the impact of extreme rainfall scenarios. To regenerate the local meteorological data, numerical model-based simulations using global boundary conditions are required at finer Spatio-temporal scales. To this end, integrated land surface models which can provide the maximum likelihood of observed rainfall can be of great significance, especially in urban complexes. Weather Research Forecasting (WRF) model is one such numerical model that can lay down a framework to provide short-range weather forecasts by fixing site-specific physics-based parametrization schemes. This study demonstrates the application of the WRF model to provide building-scale weather forecasts based on the finer-scale Urban Canopy Model (UCM) and Local Climate Zonation (LCZ). The numerical modelling framework is set up for Bangalore city, India. Bangalore city is categorized as one of the major urban complexes with a total built-up area of 77.5%. The World Urban Database Access Portal Tool (WUDAPT), which is based on random forest classification of the ground truth training samples, is used to develop the LCZ database for the WRF model. A single-layer UCM is developed to indicate the importance of structural and aerial characteristics of static datasets with appropriate land features. WRF model runs are carried out based on global boundary conditions to provide a 24hr forecast with 3km and 1km spatial domain for the study area at an urban scale. The overall accuracy of 92% (for the built-up area) and 85% (for water bodies) is obtained for LCZs developed using the random forest classification in WUDAPT. In comparison to default configurations of WRF, the forecasts of WUDAPT-based LCZs have shown an improvement at both spatial and temporal scales. The bias (particularly the spatial shift) observed using the default WRF is reduced drastically, and the forecasts are well-matched with the observed Telemetric Rain Gauge (TRG) station rainfall datasets. Assessment of the maximum likelihood of extreme rainfall forecasts can provide a platform for the development of an integrated WRF hydrological configuration in the future. Such frameworks will be greatly beneficial for obtaining more accurate rainfall and flood forecasts.
Shedding light on the organic matter black box: Using fluorescence spectroscopy to understanding microbial sources and pathways TLF
Authors: Harris Natasha , Old Gareth , Bowes Mike , Scarlet Peter , Nicholls David , Armstrong Linda , Read Daniel , Marchant Ben , Sorensen James
Published: February 2023

The river Thames catchment  passes through rural and urban centres covering many different environments and land uses. Therefore, it is exposed to a range of stresses from sewage pollution to run off from agriculture. As such, UKCEH has been conducting water quality monitoring of the Thames since 1997, which later expanded into the Thames Initiative. The Thames Initiative collects a wide range of chemical and biological data, at 19 sites across the Upper Thames Catchment and its tributaries. For 18 months, in 2012-13, fluorescence spectroscopy and PARAFAC analysis was used to identify 4 components of fluorescent organic matter (FOM). This research focusses on the role of the fourth component, C4, which represents a tryptophan like FOM(TLF). The study is looking at the peak’s temporal variability at all 19 sites within the Thames catchment, alongside nutrient and biological data. This will enable greater understanding TLF’s sources and pathways by analysing TLF’s interaction with other nutrients and pollutants.  There is robust research linking TLF to sewerage pollution and more widely anthropogenic activity. However, the understanding of TLF as a product of insitu production from microorganisms is still in relative infancy, particularly when looking for evidence in the field at a catchment level. In this study multiple variate linear modelling using forward stepwise regression techniques have been applied to the data at each site to investigate the sources of C4 across the catchment to understand both catchment and instream processes. The possible predictors available to each model were dissolved potassium (DK), total dissolved nitrogen (TDN), dissolved calcium (DCa), total bacterial counts(TBC) and chlorophyll a. The models used between 2-3 predictors (σ=2.53, μ =0.678). DK was the most common (18 models),  followed by TBC (11 models), then DCa and TDN (both 8 models) and finally chlorophyll a (2 Models). These results suggest a dominant source of C4 across the catchment is from the wastewater as dissolved potassium is a sewerage indicator.  Secondly the occurrence of TDN or dissolved  calcium suggest a more dominate baseflow path of the fluorescence at these sites, as found in previous analysis of these sites.  However, most novelty is the regular occurrence of TBC in the models. This suggests  the C4 component has a bacteriological element as well, which means it is likely there is an important contribution of TLF by insitu-production from microorganisms.
The Sandwich seal systems: A large-scale shaft sealing experiment at the Mont Terri rock laboratory – hydration and monitoring
Authors: Wieczorek Klaus , Emmerich Katja , Schuhmann Rainer , Hesser Jürgen , Furche Markus , Shao Hua , Jaeggi David , Schefer Senecio , García-Siñeriz José Luis , Königer Franz , Mayor Juan Carlos , Norris Simon , Kim Chang Seok
Published: February 2023

Safety of deep underground repositories for high-level radioactive waste is ensured by a multi-barrier system consisting of the geological barrier (host rock) and the engineered barrier system (EBS). Shaft seals are a major part of the EBS. The German regulator demands that the interplay of barriers has to be optimized in diverse redundancy to increase reliability and robustness of the barrier system. Shaft seals should also be constructed of diverse redundant components. The design of shaft seals for generic site models of Germany includes hydraulic sealing elements that are to be realized as Sandwich sealing systems. In contrast to conventional hydraulic seals of monolithic bentonite the Sandwich sealing system consists of sealing segments (DS) of bentonites and hydraulically conductive equipotential segments (ES) (Nüesch et al., 2002). Formation water, that is penetrating the hydraulic seal via preferential flow paths is contained in the ES and evenly distributed over the cross section of the seal. Thus, a more homogeneous hydration and swelling of the DS is obtained.In July 2019, after a two-years planning phase (Emmerich et al., 2019), a large-scale experiment was launched at the Mont Terri rock laboratory (MTRL) to demonstrate the feasibility of installation, to investigate the saturation process, to qualify monitoring techniques, and to assess the sealing effectiveness. The in-situ experiment is supported by laboratory experiments at different scales and by numerical simulation.The in-situ experiment consists of two experimental shafts of 1.18 m diameter and 10 ‑ 12.6 m depth located in the sandy facies of the Opalinus Clay. The DS in both shafts are constructed of German Ca-bentonites, while the ES consist of fine-grained sand. Both Sandwich sealing systems are hydrated with Pearson water type A3. Both shafts were drilled in 2020 and Shaft 1 was installed subsequently. Hydration of Shaft 1 started in May 2021. Shaft2 was installed about two years later so that experience from Shaft 1 operation could be included. Additionally, an excavation damaged zone had the chance to develop close to the shaft wall.The presentation will focus on the operation phase of the two shafts. Measurement systems and monitoring results, in terms of the evolution of water content, stress, pore pressure, and relative humidity in the sealing systems will be presented.AcknowledgmentThe Sandwich pre-project and the Sandwich in-situ experiment were/are funded by the German Federal Ministry for Economic Affairs and Energy under contracts 02E11587 and 02E11799.
Portable X-Ray Fluorescence calibration – Workflow to Optimize the Analysis of Carbonates.
Authors: Da Silva Anne-Christine , triantafyllou antoine , Delmelle Nicolas
Published: February 2023

Portable X-Ray fluorescence (PXRF) instruments have become more and more common tools in the last few years for chemical analysis (major, minor and some traces elements) in carbonates and sedimentary rocks. PXRF is a relatively cheap and fast technique, non-destructive and prevents tedious sample preparation. Manufacturers calibrations are usually made for a very large range of rock types or materials but specific empirical calibrations are essential to improve the quantification of multi-elemental concentrations.We present a general workflow for building an empirical calibration model for a PXRF spectrometer from choosing reference materials to validating calibration’s efficiency and quantifying its limit of quantification. We also compare the quantified results on a sedimentary rock suite obtained from sixteen calibrations that were built using several software available on the market, including a simple homemade spreadsheet, the Bruker calibration software named EasyCal, a free and open-source calibration app named CloudCal, and the built-in GeoMining and GeoExplorer calibrations provided by Bruker manufacturer on the Tracer 5 PXRF. This decoupled approach allows (i) to explore the pros and cons for each calibration software solutions, (ii) to investigate and weight the effect of each correction parameters (i.e. regression line geometry, peaks interferences, spectra normalization, influence coefficients, multi-phases excitation conditions) on the quantified results and (iii) to propose an original and empirical approach to estimate the lower limit of quantification (LOQ) of a PXRF instrument and its calibration.For quality check, each of these newly built calibrations was then validated on carbonate samples of known composition, corresponding to a series of Devonian limestones (Belgium) showing a large CaCO3 content ranging between 20 and 99 wt% and for which powder press pellets were formerly measured on a laboratory WD-XRF. These matrix-match empirical calibrations are systematically bringing improvement of the quantification efficiency, compared to the manufacturer calibrations. 
Quantitative disaster risk assessment for railway:challenges and a promising solution based on BIM+GIS
Authors: Cao Yiming , Lan Hengxing , Li Langping
Published: February 2023

Natural hazards are a constant risk to railway engineering facilities. Railway disaster risk assessment is an essential approach to disaster prevention. One of the main issues is that most risk assessments do not quantify particular damages, such as economic losses and human casualties, especially problematic for railway projects with intricate infrastructure that are also vulnerable to multiple disaster risks. Therefore, this paper proposed a quantitative risk assessment (QRA) strategy for railway construction facilities based on the integration of building information modeling (BIM) and geographic information system (GIS). Firstly, the physical attributes and functional state changes of components in engineering facilities could well be visualized and dynamically monitored by establishing a refined virtual 3D model using BIM. Then, the BIM+GIS technology is further applied to the simulation of the interaction between disasters and railway engineering facilities, which can provide QRA with detailed disaster damage process information. Finally, the interdependencies in the railway system, as well as inter- and intra-system functional failure transmission methods, are discussed. This proposed BIM+GIS technology is expected to provide benefits of better refined and realistic evaluation results for railway engineering QRA procedures.
Microscopic imaging technique for solute transport in rough-walled rock fractures using micro-PIV
Authors: Kim Dahye , Yeo In Wook
Published: February 2023

Experimental observation and measurement are essential to fundamentally understanding the processes that govern fluid flow and mass transport in rough-walled fractures. The micro-PIV (micro-Particle Image Velocimetry) technique has been introduced for flow visualization inside microscale rough-walled fractures. However, the methodology for mass transport visualization has yet to be established, which is crucial for the analysis/quantification of mass transport and dispersion in rough-walled fractures. This study presented the improved micro-PIV technique to visualize mass transport and measure solute concentration in rough-walled rock fractures. Calibration processes for determining the solute concentration from the measured fluorescence intensity were presented, and measured concentrations were applied to the solute transport and dispersion analyses to validate the measurement technique. The microscopic imaging and analysis demonstrated the transition from macrodispersion to Taylor dispersion-dominant transport. As the fluid velocity increased, higher concentration gradients occurred across the fracture aperture, enabling the solute to break through rapidly along the main flow channel in the middle of the fracture aperture. We successfully visualized channelized solute transport associated with eddies that accounts for Taylor dispersion and non-Fickian transport. This technique enables phenomenon-based experimental research on fluid flow and solute transport in microscale rock fractures, which used to remain in the realm of numerical simulations. Our improved visualization technique will contribute to experimentally elucidating mass transport processes in rough-walled rock fractures.
Evaluating subsurface dams for the sustainable use of groundwater in remote small islands
Authors: Hwang Ji Won , Yeo In Wook , Lee Dae Hyoung
Published: February 2023

Islands rely on groundwater for their water resources. Groundwater overdraft lowers groundwater levels and causes seawater intrusion, which results in groundwater shortage and deterioration. Many remote small islands in the Yellow Sea of Korea suffer from water shortages. To supply 100 m3/d of groundwater to 197 island residents, a subsurface dam was constructed in Anma island (5.8 km2), Korea, from Sep. 2019 to Oct. 2020. This study assessed the effect of the subsurface dam on the groundwater sustainability of the small island. The Quaternary alluvium (0.48 km2), located in the central part of Anma island, is a main aquifer and extends to a thickness of about 40 m, which rests on the Cretaceous tuff. The water table lies approximately 5 m deep below ground and fluctuates within alluvial aquifers. The subsurface dam was installed through the alluvial layer to the top of the tuff to reduce groundwater discharge to sea and was built across the coastal alluvial aquifers. Aquifer tests found hydraulic conductivity for alluvium and tuff to be 3.910-6 and 2.8410-6 m/sec, respectively. The average water levels measured in Sep. 2019 from the five observation wells in alluvial aquifers increased in Sep. 2021 by 0.28 m (9%) after the dam construction, but the precipitation also increased by 18% in the same period. Therefore, the increase in water level could not account for enhanced groundwater storage due to the dam. Numerical simulations were carried out with annual precipitation of 1,100 mm and a recharge rate of 7.2% to evaluate the change in groundwater storage before and after the subsurface dam. The simulation results showed that the subsurface dam contributes to an increase of only 0.06 m in water level in alluvial aquifers. This represents an increase in groundwater storage of 5,760 m3 in the alluvial aquifer (considering the specific yield of 0.2), which amounts to 15% of the annual groundwater recharge of 38,016 m3 in alluvial aquifers. The additional increase in groundwater storage due to the subsurface dam could complement the scheduled groundwater development of 36,000 m3/y from the alluvial aquifers, particularly when the recharge declines due to drought. The simulation also indicated that regardless of the subsurface dam, seawater intrusion was found to be insignificant due to the small amount of groundwater pumping at 100 m3/d.