bluuebunny/crossref_metadata_2025 huggingface dataset:
Retrieving coal mine CH4 emissions using UAV-based AirCore observations and the GA-IPPF model
Authors: Shi Tianqi , Han Zeyu , Han Ge , Ma Xin , Chen Huilin , Andersen Truls , Mao Huiqin , Chen Cuihong , Zhang Haowei , Gong Wei
Published: June 2022

Abstract. The quantification of CH4 emissions from coal mines has large uncertainty owing to the lack of effective monitoring methods. In this study, we developed a genetic algorithm–interior point penalty function (GA-IPPF) model to calculate the emission rate of large point sources of CH4 based on concentration sample. This model can provide optimized dispersion parameters and self-calibrate, thus lowering the requirements for auxiliary data accuracy. Meanwhile, we evaluated the influence of multiple parameters on retrieving CH4-emission rate by the GA-IPPF, including the uncertainty of CH4 concentration measurements, the number of CH4 measurements, and the accuracy of meteorological data. Based on the atmospheric CH4 concentration measurements from a UAV-based AirCore system and the GA-IPPF model, we retrieved the CH4-emission rates from the Pniówek coal (Silesia coal mining region mine, Poland) ventilation shaft. Results show that, the CH4 concentrations reconstructed by the model is highly consistent to the measured ones. And the CH4-emission rates are variable even in a single day, ranging from 639.3±22.8 to 1415.5±68.5 kg/hour on August 18, 2017 and from 342.5±34.8 to 1449.8±57.1 kg/hour on August 21, 2017. The combination of the flexible UAV-based AirCore CH4 measurements and the robust GA-IPPF model provides an effective means to quantify CH4 emissions.
Seasonal variation of nitryl chloride and its relation to gas-phase precursors during the JULIAC campaign in Germany
Authors: Tan Zhaofeng , Fuchs Hendrik , Hofzumahaus Andreas , Bloss William J. , Bohn Birger , Cho Changmin , Hohaus Thorsten , Holland Frank , Lakshmisha Chandrakiran , Liu Lu , Monks Paul S. , Novelli Anna , Niether Doreen , Rohrer Franz , Tillmann Ralf , Valkenburg Thalassa , Vardhan Vaishali , Kiendler-Scharr Astrid , Wahner Andreas , Sommariva Roberto
Published: June 2022

Abstract. Ambient measurements of nitryl chloride (ClNO2) were performed at a rural site in Germany covering 3 periods in winter, summer, and autumn 2019 as part of the JULIAC campaign (Jülich Atmospheric Chemistry Project) that aimed for understanding the photochemical processes in air masses typical for mid-west Europe. Measurements were conducted at 50 m above ground, which was most located mainly at the nocturnal boundary layer and thus uncoupled from local surface emissions. ClNO2 is produced at nighttime by heterogeneous reaction of dinitrogen pentoxide (N2O5) on chloride ion (Cl-) containing aerosol. Its photolysis at day is of general interest as it produces chlorine (Cl) atoms that react with different atmospheric trace gases forming radicals. The highest observed ClNO2 mixing ratio was 1.6 ppbv (15-min average) in the middle of one night in September. Air masses reaching the measurement site either originated from long-range transport from the southwest and had an oceanic influence or circulated in the nearby region and were influenced by anthropogenic activities. Nocturnal maximum ClNO2 mixing ratios were around 0.2 ppbv if originating from long-range transport in nearly all seasons, while values were higher ranging from 0.4 to 0.6 ppbv for regionally influenced air. The chemical composition of long-range transported air was similar in all investigated seasons, while the regional air exhibited larger differences between the seasons. The N2O5 necessary for ClNO2 formation comes from the reaction of nitrate radicals (NO3) with nitrogen dioxide (NO2), where NO3 itself is formed by reaction of NO2 with ozone (O3). Measured concentrations of ClNO2, NO2 and O3 were used to quantify ClNO2 production efficiencies, i.e., the yield of ClNO2 formation per NO3 radical formed, and a box model was used to examine the idealized dependence of ClNO2 on the observed nocturnal O3 and NO2 concentrations. Results indicate that ClNO2 production efficiency was most sensitive to the availability of NO2 rather than that of O3 and increase with decreasing temperature. The average ClNO2 production efficiency was highest in February and September with values of 18 % and was lowest in December with values of 3 %. The average ClNO2 production efficiencies were in the range of 3 and 6 % from August to November for air masses originating from long-range transportation. These numbers are at the high end of values reported in literature indicating the importance of ClNO2 chemistry in rural environments in mid-west Europe.
Composition and Reactivity of Volatile Organic Compounds in the South Coast Air Basin and San Joaquin Valley of California
Authors: Liu Shang , Barletta Barbara , Hornbrook Rebecca S. , Fried Alan , Peischl Jeff , Meinardi Simone , Coggon Matthew , Lamplugh Aaron , Gilman Jessica B. , Gkatzelis Georgios I. , Warneke Carsten , Apel Eric C. , Hills Alan J. , Bourgeois Ilann , Walega James , Weibring Petter , Richter Dirk , Kuwayama Toshihiro , FitzGibbon Michael , Blake Donald
Published: June 2022

Abstract. Comprehensive aircraft measurements of volatile organic compounds (VOCs) covering the South Coast Air Basin (SoCAB) and San Joaquin Valley (SJV) of California were obtained in the summer of 2019. Combined with the CO, CH4, and NOx data, the total measured gas-phase hydroxyl radical reactivity (OHRTOTAL) was quantified. VOCs accounted for ~60 %−70 % of the OHRTOTAL in both basins. In particular, oxygenated VOCs (OVOCs) contributed > 60 % of the OHR of total VOCs (OHRVOC) as well as the total observed VOC mixing ratio. Primary biogenic VOCs (BVOCs) represented a minor fraction (< 2 %) of the total VOC mixing ratio but accounted for 21 % and 6 % of the OHRVOC in the SoCAB and SJV, respectively. Furthermore, the contribution of BVOCs to the OHRVOC increased with increasing OHRVOC in the SoCAB, suggesting that BVOCs was important ozone precursors during high ozone episodes. Spatially, the trace gases were heterogeneously distributed in the SoCAB with their mixing ratios and OHR significantly greater over the inland regions than the coast, while their levels were more evenly distributed in the SJV. The results highlight that a better grasp of the emission rates and sources of OVOCs and BVOCs is essential for a predictive understanding of the ozone abundance and distribution in California.
Hyper-resolution PCR-GLOBWB: opportunities and challenges of refining model spatial resolution to 1 km over the European continent
Authors: Hoch Jannis Michael , Sutanudjaja Edwin H. , Wanders Niko , van Beek Rens , Bierkens Marc F. P.
Published: June 2022

Abstract. The quest for hydrological hyper-resolution modelling is already on-going for more than a decade. While global hydrological models (GHMs) have seen a reduction in grid size, thus far they never have been consistently applied at hyper-resolution (<= 1km) at the large scale. Here, we present the first application of the GHM PCR-GLOBWB at 1 km over Europe. We thoroughly evaluated simulated discharge, evaporation, soil moisture, and terrestrial water storage anomalies, and subsequently compared results with the ‘established’ 10 km and 50 km resolutions of PCR-GLOBWB. Subsequently, we could assess the added value of this first hyper-resolution version of PCR-GLOBWB as well as understand model and data requirements for future improvements. We found that for most variables epistemic uncertainty is still large. Merely for simulated discharge we can confidently state that model output at hyper-resolution improves over coarser resolutions. This first large-scale hyper-resolution modelling attempt shows that applying a GHM consistently is by now feasible with improved data availability and computer power. Also, simulated discharge improves due to better representation of the river network at 1 km. However, currently available observations are not yet widely available at hyper-resolution or lack sufficiently long timeseries, which makes it difficult to assess the performance of the model for other variables at hyper resolution. At the model side, hyper-resolution applications require improved parameterization and implementation of physical processes to be able to resemble the dynamics and spatial heterogeneity at 1 km. With this first application of PCR-GLOBWB at 1 km, we contribute to meeting the ‘grand challenge’ of hyper-resolution modelling. As such, it should be seen as a modest milestone on a longer journey towards locally relevant model output which requires a community effort from both model developers and data providers.
Oil-palm management alters the spatial distribution of amorphous silica and mobile silicon in topsoils
Authors: Greenshields Britta , von der Lühe Barbara , Hughes Harold James , Stiegler Christian , Tarigan Suria , Tjoa Aiyen , Sauer Daniela
Published: June 2022

Abstract. Effects of oil-palm (Elaeis guineensis Jacq.) management on silicon (Si) cycling under smallholder oil-palm plantations have hardly been investigated. As oil palms are Si accumulators, we hypothesized that management practices and topsoil erosion may cause Si losses and changes in spatial Si concentration patterns in topsoils under oil-palm cultivation. To test this hypothesis, we took topsoil samples under mature oil-palm plantations in well-drained and riparian areas of Jambi Province, Indonesia. The samples were taken from four different management zones within each oil-palm plot: palm circles, oil-palm rows, interrows and below frond piles. We quantified mobile Si (SiM) and Si in amorphous silica (SiAm) by CaCl2 and NaCO3 extraction, respectively. Both fractions are important Si pools in soils and are essential for plant-soil Si cycling. We further installed sediment traps on sloping, well-drained oil-palm plantations to estimate the annual loss of soil and SiAm caused by erosion. In well-drained areas, mean topsoil SiAm concentrations were significantly higher below frond piles (3.97 ±1.54 mg g-1) compared to palm circles (1.71± 0.35 mg g-1), oil-palm rows (1.87 ± 0.51 mg g-1) and interrows (1.88 ± 0.39 mg g-1). In riparian areas, highest mean topsoil SiAm concentrations were also found below frond piles (2.96 ± 0.36 mg g-1) and in grass-covered interrows (2.71 ± 0.13 mg g-1), whereas topsoil SiAm concentrations of palm circles were much lower (1.44 ± 0.55 mg g-1). We attributed the high SiAm concentrations in topsoils under frond piles and in grass-covered interrows to phytolith release from decaying oil-palm fronds, grasses, and sedges. The significantly lower SiAm concentrations in palm circles (in both well-drained and riparian areas), oil-palm rows and unvegetated interrows (only in well-drained areas) were explained by a lack of litter return to these management zones. Mean topsoil SiM concentrations were in a range of ~10 – 20 µg g-1. They tended to be higher in riparian areas, but the differences between well-drained and riparian sites were not statistically significant. Soil-loss calculations based on erosion traps confirmed that topsoil erosion was considerable in oil-palm interrows on slopes. Erosion estimates were in a range of 4 – 6 Mg ha-1 yr-1, involving SiAm losses in a range of 5 – 9 kg-1 ha-1 yr-1. Based on the observed spatial Si patterns, we concluded that smallholders could efficiently reduce erosion and support Si cycling within the system by (1) maintaining a vegetation cover in oil-palm rows and interrows, (2) incorporating oil-palm litter into farm management and (3) preventing soil compaction and surface-crust formation.
Assessing riverbank erosion in Bangladesh using time series of Sentinel-1 radar imagery in the Google Earth Engine
Authors: Freihardt Jan , Frey Othmar
Published: June 2022

Abstract. Riverbank erosion occurs along many of the Earth’s river systems, affecting riverine populations by destroying agricultural land and housing. In this study, we detected past events of riverbank erosion along the Jamuna River in Bangladesh using time series of Sentinel-1 satellite radar imagery, ground range detected (GRD) data with a 12-day revisit cycle, available in the Google Earth Engine (GEE). Eroded land is detected by performing a land cover classification and by detecting land cover changes from vegetated areas before the monsoon to sand or water after the monsoon. Further, settlements are detected as persistent scatterers, and classified as eroded if they are located on eroded land. We found that with Sentinel-1 data, erosion locations can be determined already one month after the end of the monsoon, and hence potentially earlier than using optical satellite images which depend on cloud-free daylight conditions. Further, we developed an interactive GEE-based online tool allowing the user to explore where riverbank erosion has destroyed land and settlements along the Jamuna in five monsoon seasons (2015–2019). The source code of our implementation is publicly available, providing the opportunity to reproduce the results, to adapt the algorithm and to transfer our results to assess riverbank erosion in other geographical settings.
Hydrodynamic and hydrological processes within a variety of coral reef lagoons: Field observations during 6 cyclonic seasons in New Caledonia
Authors: Bruyère Oriane , Soulard Benoit , Lemonnier Hugues , Laugier Thierry , Hubert Morgane , Petton Sébastien , Desclaux Térence , Van Wynsberge Simon , Le Tesson Eric , Lefèvre Jérôme , Dumas Franck , Kayara Jean-François , Bourassin Emmanuel , Lalau Noémie , Antypas Florence , Le Gendre Romain
Published: June 2022

Abstract. From 2014 to 2021, extensive monitoring of hydrodynamics was deployed within a variety of lagoons of New Caledonia during 6 tropical cyclone seasons. Globally, those coastal physical observations encompassed five different lagoons (four of which were never monitored before) and at least eight major atmospheric events ranging from tropical depression to category 4 cyclone. The main objectives were to characterize the processes at stake controlling hydrodynamics and hydrology of these lagoons (e.g ocean-lagoon exchanges, circulation, level dynamics, temperature and salinity variability) and capture their magnitude of change during extreme events. An additional objective was to build an adequate data set for assessment of high-resolution hydrodynamics models. Those field experiments took place within the PRESENCE project (PRESsures on coral Ecosystems of New CalEdonia) which aimed at building an efficient representation of the land-lagoon-ocean continuum of Grande Terre (main land) lagoons. Autonomous oceanographic instruments were moored at strategic locations to collect time-series of temperature, salinity, pressure, eulerian currents which characterize hydrodynamics at best. During field trips, whenever possible, lagrangian drifters releases and cross-shore hydrological profiles radials were additionally carried out. Surveys begun chronologically with SPHYNX campaign which lasted 15 months (December 2014 to February 2016) in the Hienghène-Touho lagoon followed with 5 months records in NOUMEA lagoon (December 2016 to April 2017). ELADE campaign in Poe lagoon encompassed 2 periods of measure (February to April 2018 and June to August 2018). In Koumac lagoon, CADHYAK survey was carried out between December 2019 until the end of May 2020 and finally, data have been recorded continuously for 9 months in Moindou lagoon (NEMO) (September 2020 to April 2021). In addition to characterize these lagoons, this data set stresses out some important features and processes, such as the presence of internal waves on reef slopes, wave-driven fluxes over reef barrier and exchanges through passes. It also contains the signatures of strong events materialized by surges, thermal drops inside lagoons or massive flash flood plumes dispersion. Raw data sets were processed, quality-controlled and validated, and processed files are publicly available in dedicated repositories on Seanoe in NetCDF format. Links (DOI) of individual data sets are provided herein.
Long-Term Ash Dispersal Dataset of the Sakurajima Taisho Eruption for Ashfall Disaster Countermeasure
Authors: Rahadianto Haris , Tatano Hirokazu , Iguchi Masato , Tanaka Hiroshi L. , Takemi Tetsuya , Roy Sudip
Published: June 2022

Abstract. We present the ashfall deposit and airborne ash concentration dataset from ash dispersal simulation of a large-scale explosive volcanic eruption as a reference for ashfall disaster countermeasure. We select the Taisho (1914) eruption in Sakurajima volcano, regarded as the strongest eruption in Japan in the last century, as our case study to provide a baseline for the worst-case scenario. We employ one eruption scenario approach by replicating the actual eruption under various extended weather conditions to show how it would affect contemporary Japan. Accumulated ashfall has devastating impacts on both surrounding areas of the volcano and other regions, affecting airline transportation, socio-economics activities, and human health. Therefore, it is crucial to discover places with a high probability of exposure to ashfall deposition. This knowledge can help assess the additional risk in the infrastructures, human lives, and economic impacts to make a better volcanic eruption response plan. We generate the ash dispersal dataset by simulating the ash transport of the Taisho eruption scenario with a volcanic ash dispersal model and meteorological reanalysis data for 64 years (1958–2021). We explain the dataset production process and provide the dataset in multiple formats for broader audiences. We also clarify the validity of the dataset with its limitations and uncertainties. The dataset is available at the DesignSafe-CI Data Depot: https://www.designsafe-ci.org/data/browser/public/designsafe.storage.published/PRJ-2848v2 or through the DOI: https://www.doi.org/10.17603/ds2-vw5f-t920 by selecting Version 2 (Rahadianto and Tatano, 2020).
Tropospheric water vapor: A comprehensive high resolution data collection for the transnational Upper Rhine Graben region
Authors: Fersch Benjamin , Wagner Andreas , Kamm Bettina , Shehaj Endrit , Schenk Andreas , Yuan Peng , Geiger Alain , Moeller Gregor , Heck Bernhard , Hinz Stefan , Kutterer Hansjörg , Kunstmann Harald
Published: June 2022

Abstract. Tropospheric water vapor is among the most important trace gases of the Earth’s climate system and its temporal and spatial distribution is critical for the genesis of clouds and precipitation. Due to the pronounced dynamics of the atmosphere and the non-linear relation of air temperature and saturated vapor pressure, it is highly variable which hampers the development of high resolution and three-dimensional maps of regional extent. As a complement to the sparsely distributed radio sounding observation network, GNSS meteorology and interferometric radar satellite remote sensing can assist with their complementary high temporal or spatial resolution. In addition, data fusion with collocation and tomography methods enables the construction of detailed maps in either two or three dimensions. By assimilation of these observation based datasets into regional dynamic atmospheric models the optimal state of the tropospheric water vapor conditions can be guessed. In the following, a collection of basic and processed datasets, obtained with the above listed methods, is presented that describes the state and course of atmospheric water vapor within the range of the GNSS Upper Rhine Graben Network (GURN) region.
The effect of lithology on the relationship between denudation rate and chemical weathering pathways – evidence from the eastern Tibetan Plateau
Authors: Bufe Aaron , Cook Kristen L. , Galy Albert , Wittmann Hella , Hovius Niels
Published: June 2022

Abstract. The denudation of rocks in mountain belts exposes a range of fresh minerals to the surface of the Earth that are chemically weathered by acidic and oxygenated fluids. The impact of the resulting coupling between denudation and weathering rates fundamentally depends on the types of minerals that are weathering. Whereas silicate weathering sequesters CO2, the combination of sulfide oxidation and carbonate dissolution emits CO2 to the atmosphere. Here, we combine the concentrations of dissolved major elements in stream waters with 10Be basin-wide
denudation rates from 35 small catchments in eastern Tibet to elucidate the
importance of lithology in modulating the relationships between denudation
rate, chemical weathering pathways, and CO2 consumption or release. Our catchments span 3 orders of magnitude in denudation rate in low-grade flysch, high-grade metapelites, and granitoid rocks. For each stream, we estimate the concentrations of solutes sourced from silicate weathering, carbonate dissolution, and sulfide oxidation using a mixing model. We find that for all lithologies, cation concentrations from silicate weathering are largely independent of denudation rate, but solute concentrations from carbonates and, where present, sulfides increase with increasing denudation rate. With increasing denudation rates, weathering may therefore shift from consuming to releasing CO2 in both (meta)sedimentary and granitoid lithologies. For a given denudation rate, we report dissolved solid concentrations and inferred weathering fluxes in catchments underlain by (meta)sedimentary rock that are 2–10 times higher compared to catchments containing granitoid lithologies, even though climatic and topographic parameters do not vary systematically between these catchments. Thus, varying proportions of exposed (meta)sedimentary and igneous rocks during orogenesis could lead to changes in the sequestration and release of CO2 that are independent of denudation rate.
The Potential for Using Video Games to Teach Geoscience: Learning About the Geology and Geomorphology of Hokkaido (Japan) from Playing Pokémon Legends: Arceus
Authors: McGowan Edward G. , Alcott Lewis J.
Published: June 2022

Abstract. In recent years, the concept of using video games as a form of geoscience communication has been gaining momentum. Popular commercial video games see millions of people around the world immersed in wonderous landscapes, many filled with real geological features including volcanoes, mineral deposits, and dinosaurs. Even though these features can be overlooked by many players as simple video game tropes, if utilised in educational environments or scientific outreach events, such video games could be used to encourage and stimulate the teaching of geoscientific concepts, both in the classroom or in their own time. This paper will focus on the geo-educational potential of Pokémon Legends: Arceus, the latest game in the popular Pocket-Monster franchise, Pokémon. Released at the start of 2022 on the Nintendo Switch, the game saw over 6.5 million players in its first week explore the virtual open-world landscape of Hisui. Unlike several popular commercial video games that are set in a fictional landscape, Hisui is directly based on the real-world island of Hokkaido, northern Japan. From an educational standpoint, Pokémon Legends: Arceus could be used as a powerful tool to help younger students engage more in their learning by utilising their natural affinity to the popular game and showcasing the many geological and geomorphological features found across the landscape of Hisui. This paper showcases how geological and geomorphic features can be identified in the game and researched using formal (peer-reviewed literature) and informal (online websites) resources to learn about the geological origin of their real-world counterparts on Hokkaido. Applications for this study could prove to be extremely useful for not only increasing interest and facilitating the self-learning of geoscience worldwide, but also for teaching in educational environments.
Multiple same-level and telescoping nesting in GFDL's dynamical core
Authors: Mouallem Joseph , Harris Lucas , Benson Rusty
Published: June 2022

Abstract. Two-way multiple same-level and telescoping grid nesting capabilities are implemented in the Geophysical Fluid Dynamics Laboratory (GFDL)'s Finite-Volume Cubed-Sphere Dynamical Core (FV3). Simulations are performed within GFDL's System for High-resolution modeling for Earth-to-Local Domains (SHiELD) using global and regional multiple nest configurations. Results show that multiple same-level and multi-level telescoping nests were able to capture various weather events in greater details by resolving smaller-scale flow structures. Two-way updates do not introduce numerical errors in their corresponding parent grids where the nests are located. The cases of Hurricane Laura's landfall and an atmospheric river in California were found to be more intense with increased levels of telescoping nesting. All nested grids run concurrently, and adding additional nests with computer cores to a setup does not degrade the computational performance nor increase the simulation run time if the cores are optimally distributed among the grids.
Implementation and sensitivity analysis of a Dam-Reservoir OPeration model (DROP v1.0) over Spain
Authors: Sadki Malak , Munier Simon , Boone Aaron , Ricci Sophie
Published: June 2022

Abstract. The prediction of water resource evolution is considered to be a major challenge for the coming century, particularly in the context of climate change and increasing demographic pressure. Water resources are directly linked to the continental water cycle and the main processes modulating changes can be represented by global hydrological models. However, anthropogenic impacts on water resources, and in particular the effects of dams-reservoirs on river flows, are still poorly known and generally neglected in coupled land surface – river routing models. This paper presents a parameterized reservoir model, DROP (Dam-Reservoir OPeration model), based on Hanasaki’s scheme to compute monthly releases given inflows, water demands and the management purpose. With its significantly anthropized river basins, Spain has been chosen as a study case for which simulated outflows and water storage variations are evaluated against in situ observations over the period 1979–2014. Using a default configuration of the reservoir model, results reveal its positive contribution in representing the seasonal cycle of discharge and storage variation, specifically for large-storage capacity irrigation reservoirs. Based on a bounded version of the Nash-Sutcliffe Efficiency (NSE) index, called C2M , the overall outflow representation is improved by 43 % in the median. For irrigation reservoirs, the improvement rate reaches 80 %. A comprehensive sensitivity analysis of DROP model parameters was conducted based on the performance of C2M on outflows and volumes using the Sobol method. The results show that the most influential parameter is the threshold coefficient describing the demand-controlled release level. The analysis also reveals the parameters that need to be focused on in order to improve river flow or reservoir water storage modeling by highlighting the difference in the individual effects of the parameters and their interactions depending on whether one focuses on outflows or volume mean seasonal patterns. The results of this generic reservoir scheme show promise for modeling present and future reservoir impacts on the continental hydrology within global land surface – river routing models.
The CryoGrid community model (version 1.0) – a multi-physics toolbox for climate-driven simulations in the terrestrial cryosphere
Authors: Westermann Sebastian , Ingeman-Nielsen Thomas , Scheer Johanna , Aalstad Kristoffer , Aga Juditha , Chaudhary Nitin , Etzelmüller Bernd , Filhol Simon , Kääb Andreas , Renette Cas , Schmidt Louise Steffensen , Schuler Thomas Vikhamar , Zweigel Robin B. , Martin Léo , Morard Sarah , Ben-Asher Matan , Angelopoulos Michael , Boike Julia , Groenke Brian , Miesner Frederieke , Nitzbon Jan , Overduin Paul , Stuenzi Simone M. , Langer Moritz
Published: June 2022

Abstract. The CryoGrid community model is a flexible toolbox for simulating the ground thermal regime and the ice/water balance for permafrost and glaciers, extending a well-established suite of permafrost models (CryoGrid 1, 2 and 3). The CryoGrid community model can accommodate a wide variety of application scenarios, which is achieved by fully modular structures through object-oriented programming. Different model components, characterized by their process representations and parametrizations, are realized as classes (i.e. objects) in CryoGrid. Standardized communication protocols between these classes ensure that they can be stacked vertically. For example, the CryoGrid community model features several classes with different complexity for the seasonal snow cover which can be flexibly combined with a range of classes representing subsurface materials, each with their own set of process representations (e.g. soil with and without water balance, glacier ice). We present the CryoGrid architecture as well as the model physics and defining equations for the different model classes, focusing on one-dimensional model configurations which can also interact with external heat and water reservoirs. We illustrate the wide variety of simulation capabilities for a site on Svalbard, with point-scale permafrost simulations using e.g. different soil freezing characteristics, drainage regimes and snow representations, as well as simulations for glacier mass balance and a shallow water body. The CryoGrid community model is not intended as a static model framework, but aims to provide developers with a flexible platform for efficient model development. In this study, we document both basic and advanced model functionalities to provide a baseline for the future development of novel cryosphere models.
A Local Particle Filter and Its Gaussian Mixture Extension Implemented with Minor Modifications to the LETKF
Authors: Kotsuki Shunji , Miyoshi Takemasa , Kondo Keiichi , Potthast Roland
Published: June 2022

Abstract. A particle filter (PF) is an ensemble data assimilation method that does not assume Gaussian error distributions. Recent studies proposed local PFs (LPFs), which use localization as in the ensemble Kalman filter, to apply the PF for high-dimensional dynamics efficiently. Among others, Penny and Miyoshi developed an LPF in the form of the ensemble transform matrix of the Local Ensemble Transform Kalman Filter (LETKF). The LETKF has been widely accepted for various geophysical systems including numerical weather prediction (NWP) models. Therefore, implementing consistently with an existing LETKF code is useful. This study developed a software platform for the LPF and its Gaussian mixture extension (LPFGM) by making slight modifications to the LETKF code with a simplified global climate model known as Simplified Parameterizations, Primitive Equation Dynamics (SPEEDY). A series of idealized twin experiments were accomplished under the ideal model assumption. With large inflation by the relaxation to prior spread, the LPF showed stable filter performance with dense observations but became unstable with sparse observations. The LPFGM showed more accurate and stable performances than the LPF with both dense and sparse observations. In addition to the relaxation parameter, regulating the resampling frequency and the amplitude of Gaussian kernels was important for the LPFGM. With a spatially inhomogeneous observing network, the LPFGM was superior to the LETKF in sparsely observed regions where the background ensemble spread and non-Gaussianity are larger. The SPEEDY-based LETKF, LPF, and LPFGM systems were available as open-source software on Github (https://github.com/skotsuki/speedy-lpf) and can be adapted to various models relatively easily like the LETKF.
Climate sensitivity of the summer runoff of two glacierised Himalayan catchments with contrasting climate
Authors: Laha Sourav , Banerjee Argha , Singh Ajit , Sharma Parmanand , Thamban Meloth
Published: June 2022

Abstract. The future changes in runoff of Himalayan glacierised catchments will be determined by the local climate forcing and the climate sensitivity of the runoff. Here, we investigate the sensitivity of summer runoff to precipitation and temperature changes in winter-snow dominated Chandra (the western Himalaya) and summer-rain dominated upper Dudhkoshi (the eastern Himalaya) catchments. We analyse the interannual variability of summer runoff in these catchments during 1980–2018 using a semi-distributed glacio-hydrological model, which is calibrated with the available runoff and glacier mass balance observations. Our results indicate that despite the contrasting precipitation regimes, the catchments have a similar runoff response: The summer runoff from the glacierised parts of both the catchments is sensitive to temperature changes and is insensitive to precipitation changes; the summer runoff from the non-glacierised parts has an exactly opposite pattern of sensitivity for both the catchments. The precipitation-independent glacier contribution stabilises the catchment runoff against precipitation variability to some degree. The estimated sensitivities capture the characteristic ‘peak water’ in the long-term mean summer runoff, which is caused by the excess meltwater released by the shrinking ice reserve. As the glacier cover depletes, the summer runoff is expected to become more sensitive to precipitation forcing in these catchments. However, The net impact of the glacier loss on the catchment runoff may not be detectable, given the relatively large interannual runoff variability in these catchments.
Kinematics and control of a cable-driven snake-like manipulator for underwater application
Authors: Xue Fufeng , Fan Zhimin
Published: June 2022

Abstract. In view of the large volume, complex structure, and poor
performance of traditional
underwater manipulators in some complicated underwater scenarios, a cable-driven snake-like manipulator (CDSLM) is
proposed. In this paper, the kinematics model of the proposed CDSLM is
firstly established, which can be decomposed into three parts: motor–cable
kinematics, cable–joint kinematics, and joint–end kinematics. A
tip-following algorithm is then presented to weave through the
confined and hazardous spaces along a defined path with high efficiency. The main merit of the
algorithm is that only the terminal section variables need to be calculated
and recorded, which solves the problem of expensive computational cost for
the inverse kinematics of snake-like manipulators. Finally, evaluation
indexes of the path-following performance are proposed to evaluate the effect of
the tip-following algorithm. Simulations of the path-tracking performance
are carried out using MATLAB. The results demonstrate that the average
computation time is about 1.6 ms, with a deviation of less than 0.8 mm from
the desired path, and the stability and effectiveness of the tip-following
algorithm are verified.
Spatial Distribution of Vulnerability to Extreme Flood: in provincial scale of China
Authors: Li Wei , Yi Jianni , Liu Jie , Ge Wei , Zhang Hexiang , Jiao Yutie
Published: June 2022

Abstract. Flood (EF) disasters in China are characterized by large influence range, high frequency, strong burst and uneven distribution in time and space. Once the EF disaster occurs, it will pose a great threat to the people’s life safety, economic, natural and social environment. Compared with the hazards and exposure factors of EF, the vulnerability of disaster regions shows great differences due to China’s vastness and complex social and environmental background of disasters, which leads to less large-scale study at provincial-level on EF vulnerability. This study calculated the vulnerability to EF from the favorable and unfavorable factors of flood resistance of four aspects including life, economy, environment and society. The Cloud-improved Entropy Method is used to calculate the index weight, and the Fuzzy Variable Theory is used to calculate the comprehen-sive vulnerability grads. The vulnerability ranking of 31 provinces or regions in China was made according to the differences of population, social structure, economy and environment among these regions. Furthermore, synthesizing disaster science and geographic mapping, the spatial distribution map of vulnerability to EF in China was generated, which shows that vul-nerability to EF in most regions of China is in “moderate” or “severe” grade. The spatial distri-bution of the EF risk vulnerability shows (1) a decreasing trend from the regions with high pop-ulation density to regions with low population density, (2) a decreasing trend from economical-ly developed regions to economically backward regions, (3) a decreasing trend from the eastern coastal regions to the central agricultural provinces and then to the southwest, northwest and northeast regions in China. The outcome of this study maybe one of the first efforts providing research database for vulnerability to EF in large scale of China, and it is useful for future regional research and risk management.
Seasonal fire danger forecasts for supporting fire prevention management in an eastern Mediterranean environment: the case study of Attica, Greece
Authors: Karali Anna , Varotsos Konstantinos V. , Giannakopoulos Christos , Nastos Panagiotis P. , Hatzaki Maria
Published: June 2022

Abstract. Forest fires constitute a major environmental and socioeconomic hazard in the Mediterranean. Weather and climate are among the main factors influencing forest fire potential. As fire danger is expected to increase under changing climate, seasonal forecasting of weather conditions conductive to fires is of paramount importance for implementing effective fire prevention policies. The aim of the current study is to provide high resolution (~9 km) probabilistic seasonal fire danger forecasts, utilizing the Canadian Fire Weather Index (FWI) for Attica region, one of the most fire prone regions in Greece and the Mediterranean, employing the fifth generation ECMWF seasonal forecasting system (SEAS5). Results indicate that FWI and its Initial Spread Index (ISI) sub-component, present statistically significant high discrimination scores and are proven respectively, marginally useful, and perfectly reliable in predicting above normal fire danger conditions. When comparing year-by-year the fire danger predictions with the historical fire occurrence obtained by the Hellenic Fire Service database, both seasonal FWI and ISI forecasts indicate a skill in identifying years with high fire occurrences. Overall, fire danger and its sub-components can potentially be exploited by regional authorities in fire prevention management regarding preparedness and resources allocation in the Attica region.
Potential tsunami hazard of the southern Vanuatu Subduction Zone: tectonics, case study of the Matthew Island tsunami of 10 February 2021 and implication in regional hazard assessment
Authors: Roger Jean , Pelletier Bernard , Gusman Aditya , Power William , Wang Xiaoming , Burbidge David , Duphil Maxime
Published: June 2022

Abstract. The Vanuatu subduction zone (VSZ) is known to be seismically very active, releasing a significant energy resulting of the quick convergence rate between the Australian and Pacific tectonic plates. That is not the case on its southernmost part south of latitude 22.5° S and east of longitude 170° E which is neither known as being highly tectonically active nor having produced large tsunamis over the past 150 years, and by the way, has not been much studied. On the 11th of February 2021 (10 February UTC), a magnitude Mw 7.7 earthquake triggered a tsunami warning in New Caledonia and Vanuatu twenty minutes after midnight (local time). With an epicentre located close to the volcanic islands of Matthew and Hunter, this shallow reverse-faulting rupture (< 30 km depth) was able to disturb the seabed and produce a tsunami. In fact, it was confirmed 45 min later by the coastal gauges of the Loyalty and the south Vanuatu islands which recorded the first tsunami waves. Showing an overall recorded amplitude of less than 1 m with a maximum of ~1.5 m in Lenakel, (Tanna, Vanuatu), it has been recorded on most coastal gauges and DART stations of the southwest Pacific Region as far as Tasmania in the South and Tuvalu in the North respectively at distances of ~3000 and ~1800 km from the epicentre. In this study, the tsunamigenic potential of the southernmost part of the VSZ and the implications in terms of regional hazard assessment are discussed through (1) the presentation of the complex tectonic settings of this “transition zone” between the Solomon-Vanuatu and the Tonga-Kermadec Trenches; (2) the case study of the 10 February 2021 tsunami at a southwest Pacific regional scale using three different tsunami generation scenarios computed with COMCOT modelling code on a set of 48 nested bathymetric grids; and (3) the simulation of a plausible Mw 8.2 scenario encompassing the active part of this “transition zone”. In fact, the validation of the Mw 7.7 parameters for tsunami modelling provides keys to further assess the hazard from potential tsunami triggered by higher magnitude earthquakes in this region. Finally, it helps to highlight the significant role played by the numerous submarine features in the region, the Norfolk Ridge being the most important acting like a waveguide toward the north and the south.
First evidence of microplastics in Antarctic snow
Authors: Aves Alex R. , Revell Laura E. , Gaw Sally , Ruffell Helena , Schuddeboom Alex , Wotherspoon Ngaire E. , LaRue Michelle , McDonald Adrian J.
Published: June 2022

Abstract. In recent years, airborne microplastics have been identified in a range of remote environments. However, data throughout the Southern Hemisphere, in particular Antarctica, are largely absent to date. We collected snow samples from 19 sites across the Ross Island region of Antarctica. Suspected microplastic particles were isolated and their composition confirmed using micro-Fourier transform infrared spectroscopy (µFTIR). We identified microplastics in all Antarctic snow samples at an average concentration of 29 particles L−1, with fibres the most common morphotype and polyethylene terephthalate (PET) the most common polymer. To investigate sources, backward air mass trajectories were run from the time of sampling. These indicate potential long-range transportation of up to 6000 km, assuming a residence time of 6.5 d. Local sources were also identified as potential inputs into the environment as the polymers identified were consistent with those used in clothing and equipment from nearby research stations. This study adds to the growing body of literature regarding microplastics as a ubiquitous airborne pollutant and establishes their presence in Antarctica.
The eco-conscious wind turbine: bringing societal value to design
Authors: Canet Helena , Guilloré Adrien , Bottasso Carlo L.
Published: June 2022

Abstract. Wind turbines are designed to minimize the cost of energy, a metric aimed at making wind competitive with other energy-producing technologies. However, now that wind energy is competitive, how can we increase its value for society? And how much would a societal gain cost other stakeholders, such as investors or consumers? This paper tries to answer these questions from the perspective of wind turbine design. Although wind turbines produce green renewable energy, they also generate various impacts on the environment, as all human endeavours. Among all impacts, the present work adopts the environmental effects produced by a turbine over its entire life cycle, expressed in terms of CO2-equivalent emissions. A new approach to design is proposed, whereby Pareto fronts of solutions are computed to define optimal trade-offs between economic andenvironmental goals. The new proposed methodology is demonstrated on the redesign of a baseline 3 MW wind turbine at two locations in Germany, differing for typical wind speeds. Among other results, it is found that, in these conditions, a 1 % increase in the cost of energy can buy about a 5 % decrease in the environmental impact of the turbine. Additionally, it is also observed that in the specific case of Germany, very low specific-power designs are typically favored, because they produce more energy at low wind speeds, where both the economic and environmental values of wind are higher. Although limited to the sole optimization of wind-generating assets at two different locations, these results suggest the existence of new opportunities for the future development of wind energy where, by shifting the focus slightly away from a purely cost-driven short-term perspective, longer-term benefits for the environment (and, in turn, for society) may be obtained.
Flight Trajectory Optimization of Fly-Gen AWE Systems through a Harmonic Balance Method
Authors: Trevisi Filippo , Castro-Fernández Iván , Pasquinelli Gregorio , Riboldi Carlo Emanuele Dionigi , Croce Alessandro
Published: June 2022

Abstract. The optimal control problem for flight trajectories for Fly-Gen Airborne Wind Energy Systems (AWES) is a crucial research topic for the field, as suboptimal paths can lead to a drastic reduction in power production. One of the novelties of the present work is the expression of the optimal control problem in the frequency domain through a Harmonic Balance formulation. This allows to reduce the problem size by solving only for the main harmonics and to implicitly impose periodicity of the solution. The trajectory is described by the Fourier coefficients of the dynamics (elevation and azimuth angles) and of the control inputs (on-board wind turbines thrust and AWES roll angle). To isolate the effects of each physical phenomenon, optimal trajectories are presented with an increasing level of physical representation from the most idealized case: i) If the mean thrust power (mechanical power linked to the dynamics) is considered as the objective function, optimal trajectories are characterized by a constant AWES velocity over the loop and a circular shape. This is done by converting all the gravitational potential energy into electrical energy. At low wind speed, on-board wind turbines are then used as propellers in the ascendant part of the loop; ii) If the mean shaft power (mechanical power after momentum losses) is the objective function, a part of the potential energy is converted into kinetic and the rest into electrical energy. Therefore, the AWES velocity fluctuates over the loop; iii) If the mean electrical power is considered as the objective function, the on-board wind turbines are never used as propellers because of the power conversion efficiency. Optimal trajectories for case ii) and iii) have a circular shape squashed along the vertical direction. The optimal control inputs can be generally modelled with one harmonic for the on-board wind turbines thrust and two for AWES roll angle without a significant loss of power, demonstrating that the absence of high-frequency control is not detrimental to the power generated by Fly-Gen AWES.
Wind turbine wake simulation with explicit algebraic Reynolds stress modeling
Authors: Baungaard Mads , Wallin Stefan , van der Laan Maarten Paul , Kelly Mark
Published: June 2022

Abstract. Reynolds-averaged Navier-Stokes (RANS) simulations of wind turbine wakes are usually conducted with two-equation turbulence models based on the Boussinesq hypothesis, which are simple and robust but lack the capability of predicting various turbulence phenomena. Using the explicit algebraic Reynolds stress model (EARSM) of Wallin and Johansson (2000) can aid some of these deficiencies, while still being numerical robust and only slightly more computationally expensive than the traditional two-equation models. The model implementation is verified with the homogeneous shear flow, half-channel flow and square duct flow cases, and subsequently full 3D wake simulations are run and analyzed. The results are compared with reference large eddy simulation (LES) data, which shows that the EARSM especially improves the prediction of turbulence anisotropy and turbulence intensity but that it also predicts less Gaussian shaped wake profiles with the standard settings of the model.