bluuebunny/crossref_metadata_2025 huggingface dataset:
Aggregation and charging of mineral cloud particles underhigh-energy irradiation
Authors: Bach-Møller Nanna , Helling Christiane , Gråe Jørgensen Uffe , Bødker Enghoff Martin
Published: February 2023

Previous studies have found that high-energy radiation like cosmic rays and stellar energetic particles, can induce the initial nucleation of cloud particles from molecular clusters, but the effect on larger existing particles is still poorly understood.
This study explores the question “How is the aggregation of mineral cloud particles affected by high-energy radiation and humidity?”. We present experiments conducted in an atmosphere chamber on the charging and aggregation of 50nm SiO2 particles under varying degrees of gamma radiation and relative humidity. We observe an aggregation of the SiO2 particles to form larger clusters, and that this aggregation is inhibited by irradiation with gamma radiation. We find that non-irradiation SiO2 particles are generally more positively charged in comparison to a bipolar charge distribution, and that gamma radiation shifts the particles to a more negative charge. The effect of gamma radiation on the aggregation and charge of the particles is present both at lower (~20%) and higher (~60%) relative humidity. When varying the relative humidity from ~20% to ~80% we find no significant direct effect of relative humidity on the aggregation of the particles. These results are presented and discussed in relation to previous studies of nucleation and condensation.
In recent years, exoplanet research has focused on how we can interpret atmosphere observations through models, and here cloud formation has proven to be a challenge. Clouds are known to play a role in both the energy balance and chemistry of atmospheres, as well as directly affecting the spectrum observed from a planet. Exoplanet clouds are believed to be very chemically heterogeneous and SiO2 is one of the species that easily condense, making SiO2 relevant both as a nucleation seed on Earth-like planets and as a cloud species on Exoplanets. Since cloud formation has been found to be affected not only by the atmospheric properties, but also by high-energy radiation from outside the atmosphere it indicates that the host star and interstellar environment of an exoplanet might affect its clouds.
Carbon footprint and reduction initiatives in a French geosciences laboratory
Authors: Jeanneau Laurent , Jardé Emilie , Argentin Anne-Laure , Battais Annick , Bernard Thomas , Coche Alexandre , Fournereau Marion , Moreau Frédérique , Guerit Laure
Published: February 2023

The impact of our productivist societies on our environment is now clearly demonstrated. It is illustrated in particular by the alteration of biogeochemical flows, the erosion of biodiversity, the chemical pollution of environments, the anthropisation of soils, the alteration of the water cycle, the acidification of the oceans and climate change.As higher education and research staff working at the interface between science and society, we are aware of the need for an environmental transition that can only be achieved by reducing our greenhouse gas emissions and our environmental impact. We do not believe that the content of our research justifies any form of exemption and are aware of the benefits of being exemplary. As a research lab, we are committed to participating in limiting the increase in the Earth's average temperature, ideally targeted at less than 1.5°C compared to the pre-industrial period. This objective requires achieving carbon neutrality by 2050.From 2021 the Sustainable Development & Social Responsibility working group of the research laboratory “Géosciences Rennes” has been created (i) to determine the C footprint by using GES1.5 (Research Consortium labo1.5), (ii) to communicate and raising staff awareness of the climate emergency, (iii) to propose indicators for reducing the carbon footprint, (iv) to convey a message to the supervisory authorities to work on the various reduction items.The calculated C footprint includes heating of buildings, electricity, purchase of goods and services, scientific missions and commutes. Between 2019 and 2021, the C footprint was 879, 520 and 708 T CO2eq, which corresponds to 5.8, 3.6 and 5.1 T CO2eq/person. The purchase of goods and services was the main item, representing 48 ± 8 % (mean ± SD) of the C footprint. Scientific missions represented 14 ± 9 % of the C footprint. Sanitary restrictions due to the covid pandemy induced a drastic decrease of the C footprint of scientific missions from 220 T CO2eq in 2019 to 43 T CO2eq in 2020.Thanks to the GES1.5 toolkit, it is possible to identify the main emission items for a given laboratory and to design and quantify specific actions to collectively reduce the C footprint. These data were the corner stone of collaborative workshops to invent our low-carbon laboratory. This presentation will feature the data and the process of collective decision in “Géosciences Rennes” laboratory. These results highlight that achieving the European Union targets will require a rethinking of the way we do science. 
Six-component records of local seismicity in the Long Valley Caldera, Californica, US
Authors: Brokesova Johana , Malek Jiri
Published: February 2023

Long Valley Caldera in the eastern part of California is a depression 32 km long and 18 km width, which was formed during a supervolcano eruption 760 000 years ago.  Weak volcanic activity manifested by hot springs, CO2 emmanations and earthhquake swarms in the caldera and neighboring Mammoth Mountain volcanic complex has been continuing until present. The seismicity in the area is the subject of intensive study. In 2016 - 2017 the monitoring system was supplemented by small-aperture array consisting of three short-period Rotaphone-D seismographs. The instruments were deployed in vaults few hundred meters apart at depts from 3.2 to 2.2 m. They are new short-period seismographs measuring three translational and three rotational components. The array enabled new methods of microearthquakes investigation. The noise from surface sources (mainly traffic along nearby highway) can be suppressed significantly by non-linear summing of redundant translational data from each Rotaphone. This enabled detection of very weak microearthquakes in the vicinity of the array with good signal-to-noise ratio. The true azimuth and phase velocity along surface are determined by two methods:  the zero-crossing point beamforming and rotation-to-translation relations. Based on these quantities, location of microearthquakes was performed and it was compared to the locations from the USGS catalogue of local earthquakes.The six-component records in the Long Valley Caldera are extremely complex. Strong phases between P- and S-wave onsets and namely within the S-wave group are visible in most seismograms. They probably originated as reflection and refraction waves at distinctive interfaces beneath the sediment filling of the caldera. Six-component records enabled analysis of individual wavetypes in the seismograms. The seismic array was reinstalled in the summer 2021 with new data-acquisition system with bigger dynamic range (32 bits A/D converter). We expect even more sensitive measurements from this new observation. 
Recent changes of tropical night in the South Korea metropolitan area
Authors: Kang TaeHun , Yoon Donghyuck , Cha Dong-hyun , Lee Myong-In
Published: February 2023

To investigate the recent change of tropical night in South Korea, the duration and intensity of tropical nights (daily minimum temperature , Korea Meteorological Administration; KMA) were quantitatively analyzed for 40 years (1979-2018). As a result of spatiotemporal analysis, There were stronger and longer-lasting tropical nights in the Seoul metropolitan area compared to other regions of South Korea. In particular, the tropical nights over the region tended to increase more prominently in terms of intensity, frequency, and duration.The tropical night event in the metropolitan area was classified into pure-TN (no heatwave prior to tropical night) and HWTN (tropical night following heatwave). In the analysis of climatological synoptic conditions based on 40-year ERA5 data, two types of tropical night events (pure-TN and HWTN) occurred. Pure-TN occurred when a mid-level anticyclone circulation existed over the Korean Peninsula with the southwesterly which induced a positive temperature advection anomaly over the metropolitan area. Moreover, a positive low cloud cover anomaly with enhanced downward longwave radiation also prevailed. On the other hand, HWTN mainly occurred when a mid-level cyclone circulation was located over the Korean Peninsula with a positive downward shortwave radiation anomaly and a descending motion anomaly that induced adiabatic heating over the metropolitan area.Significant increasing trends in tropical night events (pure-TN: 0.143 day/year, HWTN: 0.077 day/year) appeared at 95% confidence level. The regression analysis was also conducted for three sub-analysis periods with 10 days (21-31 July;P1, 1-10 August;P2, 11-20 August;P3). Consequently, the favorable atmospheric conditions for HWTN (pure-TN) have been frequently constructed during P2 (P1, and P3).
Geofluids inferences using deep electrical resistivity tomography for a sustainable energy transition
Authors: Giampaolo Valeria , Capozzoli Luigi , De Martino Gregory , Lapenna Vincenzo , Prosser Giacomo , Olita Fabio , Boldrin Paola , Rizzo Enzo
Published: February 2023

In the last years, the use of Deep Electrical Resistivity Tomography (DERT) has become more common for the investigation of areas with complex geological setting. The considerable resolution obtained through such a technique makes it possible to discriminate much more effectively the resistivity contrasts existing in the shallower crustal levels, thus providing more reliable information on the physical conditions of the rocks, the presence of structural discontinuity surfaces, on the presence and trend in the subsoil of aquifers and/or fluids of various origins.For these reasons, some DERT investigations were carried out in a structurally complex area located close to Tramutola village, in the western side of the Agri Valley, where the largest onshore hydrocarbon reservoir in west Europe is present.The Tramutola site represented a key sector for the early petroleum exploration and exploitation of the area. Natural oil spills were historically known since the 19th century in the investigated area, and these helped the national oil company to identify the first shallower hydrocarbon traces. Furthermore, a considerable amount of sulphureous hypothermal water (~28 °C with a flow rate of 10 l/s) with associated gases (mainly CH4 and CO2) was found during the drilling of the “Tramutola2” well (404.4 m) in 1936. From a geological point of view, the study area, is characterized by the presence of a complete section of the tectonic units of the southern Apennines and a complex structural framework, not yet fully clarified, which affect fluids circulation.To foster the efficient and sustainable use of the geothermal resource in Tramutola area, surface and subsurface geological, hydrogeological and new geophysical data were combined in order deepen our knowledges about the reservoir of the hypothermal fluids and their circulation.The municipality of Tramutola is interested in the rehabilitation of the abandoned oil wells, both in terms of exploitation of the geothermal resource and for the realisation of a tourist “Park of energy”. The aim is to provide a wide audience with strategies, models, and technical skills capable of making visitors more active and critical towards the sustainable use of energy resources. Furthermore, the possible exploitation of geothermal resources of the Tramutola site represents a strategic action in the Basilicata region as a prototype of energy transition from fossil fuels to more environmentally friendly energy resources. This is also essential to satisfy the increased demand for clean energy in the area (no. 7 affordable and clean energy United Nations’ SDGs) and also contribute to climate change mitigation through the reduction of CO2 emissions (13 climate action).
Offshore wind energy climate projections for the European region
Authors: Susini Stefano , Menendez Melisa
Published: February 2023

The wind energy sector is experiencing a solid expansion towards the open sea, where higher-quality resources are available. This tendency is slowed down by the uncertainties in metocean characterization, with the wind playing a significant role as it represents both an action and a resource for the wind plant. The present study aims to investigate the climate change impact on the marine wind conditions, focusing on mean and extreme values.Atmospheric circulation patterns over the European seas are classified based on combinations of the atmospheric sea level pressure and the directional wind speed data from the ERA5 reanalysis (1985-2015). These present climate patterns are then used to assess the performance of several General Circulation Model simulations from the sixth Climate Model Intercomparison Project (CMIP6) during the present climate. The best-performing models are then analyzed to provide projections of mean and extreme wind conditions in multiple shared socio-economic scenarios (SSP1-2.6, SSP2-4-5, and SSP5-8.5) and future horizons (2030-2060 and 2700-2100).Results show a general decrease in the mean offshore wind speed over the European region, more intense in the Mediterranean Sea, while extreme wind speed will increase up to 3% along the Atlantic coast of Europe. The southeastern Atlantic coast appears to be favored in the analyzed climate change scenarios, as the extreme events are projected to reduce their intensity, while the wind resource is not expected to vary significantly.
Dynamics and variability of the MLT represented by UA-ICON
Authors: Stolle Claudia , Kunze Markus , Siddiqui Tarique , Zülicke Chistoph , Amiramjadi Mozhgan , Yamazaki Yosuke , Baumgarten Gerd , Borchert Sebastian , Schmidt Hauke
Published: February 2023

The variability of the upper atmosphere is largely influenced by dynamical forcing from the lower and middle atmosphere. The Mesosphere and Lower Thermosphere (MLT) is the transition region between the middle atmosphere and the upper atmosphere, and it determines dynamical forcing to the upper atmosphere from below. It is thus of high importance to know, describe, and understand the dynamical processes within the MLT to quantify dynamics. Therein, General Circulation Models (GCMs) have been a significant tool to explain MLT processes.However, developing the right parameterizations that allow to accurately model near-to-realistic states of the MLT by GCMs is challenging, which is reflected in a large diversity of results from different models in comparison to observations, e.g., of winds and temperatures at the MLT.In recent years, the community model ICON (Icosahedral Nonhydrostatic Weather and Climate Model) has been expanded into altitudes up to 150 km, named the UA (Upper Atmosphere) branch. UA-ICON is increasingly being applied to model and to understand MLT processes and how they are controlled by the lower and middle atmosphere.We present newly developed capabilities of UA-ICON. Examples are mesospheric cooling during stratospheric warming events, low summer mesopause temperatures through appropriate specification of gravity wave parameterizations and runs of high spatial resolution. Results are discussed in comparison with observations and with predictions by other GCMs.
From site-scale land-atmsophere water fluxes to globally gridded products: Advances with the FLUXCOM-X framework
Authors: Nelson Jacob A. , Walther Sophia , Kraft Basil , Zhang Weijie , Duveiller Gregory , Gans Fabian , Weber Ulrich , Hamdi Zayd Mahmoud , Jung Martin
Published: February 2023

While eddy covariance (EC) is a standard for measuring total ecosystem evaporation (evapotranspiration, ET), upscaling from the tower to the regional and global scales is still marred with uncertainties. Here, we explore this scale translation via the FLUXCOM-X framework, which links data from EC measurements and remote sensing to machine learning techniques to produce models for generating globally gridded products. In particular, we explore potential sources of uncertainty inherent to this pipeline and how these influence the resulting gridded products: training data quality including site-selection and coverage of in-situ data, and modelling distinct water flux components (i.e., transpiration (T) and abiotic evaporation) individually compared to total evapotranspiration.Overall, changes in the FLUXCOM-X framework compared to previous versions (Jung et al. 2019) results in tangible improvements to the spatial and temporal patterns of the global evapotranspiration products. Furthermore, the predictions of a corresponding transpiration product provide an empirical estimate of plant controlled water fluxes. The resulting global T/ET ratios are consistent with current estimates from isotopic analyses, but with the advantage of high spatio-temporal coverage. Lessons learned from this analysis provide a more targeted line of inquiry into potential avenues for further improvements in global evapotranspiration modeling.Jung, M., Koirala, S., Weber, U. et al. The FLUXCOM ensemble of global land-atmosphere energy fluxes. Sci Data 6, 74 (2019). https://doi.org/10.1038/s41597-019-0076-8
Potential for deep geothermal heat production in clastic rocks of the southern North German Basin – A case study from Hoya, Germany
Authors: Kettermann Michael , Ritzmann Oliver , Battermann Jens , Wellmann Florian
Published: February 2023

Deep geothermal aquifers can be a good source for industry applications with a high heat demand in the course of the energy transition. Industries such as paper production require heat sources that are independent of global market fluctuations, with predictable, reliable and green long-term supply. A number of clastic aquifers have been identified as potentially feasible for geothermal use within the North German Basin ranging from the lower Cretaceous to Middle Bunter Sandstone. Due to the extensive hydrocarbon exploration in the North German Basin, it is often possible to provide a local subsurface analysis of the geothermal potential at the location of the required use.In this work, we present a case study from the town of Hoya in the southern North German Basin, where an abandoned hydrocarbon exploration well is available, as well as numerous wells in the vicinity (20 km) and some 2D seismic lines. From well log analysis, well reports, seismic data and an available 3D model of Lower Saxony, we evaluate the quality of different clastic reservoirs in the study area. We found? that many of the reservoirs that are known for good quality sandstones in the North German Basin are presented as shales at the paper mill in Hoya. Potentially usable sandstone reservoirs include the lower Cretaceous Aptian (top ca. 1600 m) and Valendis Sandstone (top ca. 1700 m), the middle Jurassic Dogger Delta 2 (top ca. 1950 m) and the Lower Triassic Hardegsen Sandstone (top ca. 3850 m). Surrounding well data, however, show a large spatial heterogeneity for these lithologies over relatively short distances. We include these geological uncertainties, temperature measurements from wells, permeability measurements from well tests and the specific requirements of a paper production company to evaluate the geological and economic feasibility, based on geothermal energy estimations and levelized costs of heat for the individual reservoirs.
Reinvestigating Groundwater Drought Using In Situ and GRACE Data
Authors: Wang Jinyuan , Mallick Kaniska , Kuhlmann Natascha , Matgen Patrick , Bordas Stéphane , Pfister Laurent
Published: February 2023

Groundwater plays a unique role in the terrestrial water cycle. It is one of the prime sources of water during periods of severe drought. Depletion of groundwater reaching certain thresholds substantially lead to the degradation of water quality. Among all the hydrological variables, it has a characteristics behavior due to its lagged response to precipitation, evapotranspiration, soil water content variations, and surface water variation due to anthropogenic activities. Groundwater drought has been studied in various regions in the world, which revealed significant correlation among hydrological factors, including precipitation, soil water content, and various terrestrial water storage. Terrestrial water storage variables used for monitoring groundwater drought are total water storage change (TWSC) and groundwater storage change (GWSC). While the TWSC can be estimated from the Gravity Recovery and Climate Experiment (GRACE), GWSC can be estimated from in situ groundwater level within the network of well records using relevant hydrogeological information. Previous studies showed the ability and reliability of GRACE data in groundwater monitoring in the regions under extreme drought. Hydrological model outputs, e.g., the Global Land Data Assimilation System (GLDAS), have been used to derive groundwater drought indicators that reached certain reliability. The present study conducts a systematic investigation on the ability of the GRACE data to reflect the groundwater drought conditions, by comparing in situ groundwater data, TWSC estimated from GRACE (TWSCGRACE), GWSC estimated from the conjuncture of GRACE and GLDAS (GWSCGLDAS), Standardized Precipitation Index (SPI), and satellite land surface temperature. Further, by estimating the vadose zone water storage change (VZWC) using TWSC and in situ groundwater data (VZWCin situ), as well as using TWSC and GLDAS (VZWCGLDAS), we investigate the ability of GRACE and in situ data to monitor the vadose zone water content. Our results show that TWSCGRACE correlates better with in situ groundwater data as compared to GWSCGLDAS in all three study areas located in India, Australia, and Belgium, which are some of the hotspots suffering from intensive flash drought in the recent decade. TWSCGRACE shows stronger correlation and better consistency with SPI and land surface temperature as compared to in situ groundwater data. VZWCin situ correlates well with VZWCGLDAS but is limited to data availability from the well network. Results from GWSCGLDAS and VZWCGLDAS show that hydrological model outputs can serve as replacement or supplement to estimate GWSC and VZWC when in situ groundwater data is significantly missing.
The use of crowdsourced observations to build climate grids and assess urban heat hazard.
Authors: Mitchell Timothy D. , Fry Matthew J.
Published: February 2023

Crowdsourced observations have the potential to bring a step-change in urban climatology. This rapid prototyping project explores their potential for improving the standard observed grids, and the likely consequences for urban climate services. Basic quality control procedures are applied to WOW, Davis, Netatmo and Met Office sites around Manchester (UK), and site records of daily minimum and maximum temperatures are built. These are interpolated onto a set of daily observed grids of temperature for Manchester at 1km resolution for summer (JJA) 2020, thus obtaining a crowdsourced alternative to HadUK-Grid. The number of tropical nights (minimum > 20 degrees) is counted in these two gridded products. This provides the baseline for a current climate service for partners in local government that projects possible future changes in heat hazards. Thus the comparison of the standard and crowdsourced products gives some insight into the potential for observations from citizen science to improve gridded observations, an observed hazard metric, future projections of that metric, and so influence public policy decisions related to extreme heat.
Modelling the source of glacial earthquakes: numerical modelling of the response of a tide-water glacier to the capsize of an instable iceberg
Authors: Mangeney Anne , Bonnet Pauline , Yastrebov Vladislav , Castelnau Olivier , Leroyer Alban , Queutey Patrick , Rueckamp Martin , Sergeant Amandine
Published: February 2023

One current concern in Climate Sciences is the estimation of the annual amount of ice lost by glaciers and the corresponding rate of sea level rise. Greenland ice sheet contribution is significant with about 30% to the global ice mass losses. The processes that control ablation at tidewater glacier termini, glacier retreat and calving are complex, setting the limits to the estimation of dynamic mass loss and the relation to glacier dynamics. It involves interactions between bedrock – glacier – icebergs – ice-mélange – water – atmosphere. Moreover, the capsize of cubic kilometer scale icebergs close to a glacier front can destabilize the glacier, generate tsunami waves, and induce mixing of the water column which can impact both the local fauna and flora. We aim to improve the physical understanding of the response of glacier front to the force of a capsizing iceberg against the terminus. For this, we use a mechanical model of iceberg capsize against the mobile glacier interacting with the solid earth through a frictional contact and we constrain it with measured surface displacements and seismic waves that are recorded at teleseismic distances. Our strategy is to construct a solid dynamics model, using a finite element solver, involving a deformable glacier, basal contact and friction, and simplified iceberg-water interactions. We simulate the response of a visco-elastic near-grounded glacier to the capsize of an iceberg close to the terminus. The influence of the glacier geometry, the type of capsize, the ice properties and the basal friction on the glacier dynamic and the observed surface displacements are assessed. The surface displacements simulated with our model are then compared with measured displacements for well documented events. We show the surface and basal displacements of the glacier are significantly different in the case of to a top-out and a bottom-out (the two possible rotations) iceberg capsize.  This suggests different basal forces in both types of capsize, and thus probably a different signature in the seismic waves generated at the basal surface during capsize. To reproduce the vertical displacements of the glacier, our results suggest a higher hydrodynamic force on the glacier tongue than suggested in previous studies.
Adaptive management of Mediterranean Pinus halepensis forests in the face of climate change
Authors: Díaz Montero Asunción , Peña Molina Esther , Fajardo Cantos Álvaro , González Romero Javier , Botella Bou Raúl , Moya Navarro Daniel , de las Heras Ibáñez Jorge Antonio , Lucas Borja Manuel Esteban , Martín Alcón Santiago , Tomé Morán José Luis , Jordán Gonzalez Esteban , Coll Mir Lluis , Ameztegui González Aitor , del Campo  García Antonio , González Sanchís María
Published: February 2023

The main objective of this project is to investigation and develop new tools aimed at adapting Iberian Aleppo pine forests to climate change, as well as their demonstrative application through forest management actions. will focus on the early detection of decay processes and on the improvement of the resilience of this ecosystem by increasing its vigour, its capacity to adapt to climatic aridification and the ability to recover its functions after natural disturbances. The geographical scope of the project will cover the potential area of distribution of the habitat subtype in the Iberian Peninsula, across sub-humid and semi-arid ecological gradient, including the Mediterranean slopes of the Catalan mountains and the Iberian System, the Ebro basin and the pre-Baetic mountain ranges. This will facilitate an integrated implementation of the methodology that involving the main stakeholders that are responsible for the regulation of forest management throughout the area:- To implement silvicultural treatments aimed at improving vitality and reducing the effects of reduced water availability in a scenario of recurrence of droughts and increased evapotranspiration.- To implement adaptive treatments to improve the resilience and adaptive capacity of Aleppo pine post-fire regeneration in a scenario of higher frequency and severe wildfires.After the implementation of ecohydrology and post-fire treatments, a monitoring program will be carried out in the forest stands where the treatments have been executed. We measure physicochemical and biologic parameters of soil and vegetation. Measurements will be realized after the execution and annually to study if the treatments have had the desired effects or not.
Predicting future water demand in Austria due to climate change and demographic development
Authors: Stelzl Anika , Fuchs-Hanusch Daniela
Published: February 2023

Due to the climate change, it is expected that there will be longer dry and hot episodes in the future in Central Europe. As a result, temporary water shortages are to be expected in certain parts of Austria. Due to these changes, it is assumed that the future water demand will increase, caused by a change in consumption behavior and the increase of garden irrigations. Furthermore, an increasing population is expected, which may also lead to a shortage, especially in small supply areas.For water supply companies it is especially important to know the future change in water demand in order to be able to adapt to these changes. Therefore, a water demand forecasting model is derived in this study. In a first step, this study analyses the change in water demand in recent years and the relationship between water demand and climate indices. Furthermore, the change of the future water demand depending on the different climate change scenarios (RCP 2.6, RCP4.5 and RCP8.5) is estimated. For this purpose, different modeling approaches (e.g. multiple linear regression, random forest,…) were tested and a suitable approach is selected. The water demand forecasting model is trained and tested with water demand and weather data reaching back several years. To estimate the future change in water demand, the model is applied to the climate projections and the change between the selected reference period and the two future periods is calculated. The change in demographic development is considered in the last step.So far, we found that for the selected study site peak water demand will increase by an average between 1.5% and 5.5%, depending on the different climate change scenario for the period 2051-2070 compared with the reference period (2001-2020). It was also determined that demographic development is responsible for the majority of the increase in water demand.Acknowledgements: The presented research is funded by the Federal Ministry for Agriculture, Forestry, Regions and Water Management of the Republic of Austria
ML-based fire spread model and data pipeline optimization
Authors: Bauer Tobias , Miller Julia , Gottfriedsen Julia , Mollière Christian , Durillo Barrionuevo Juan , Hammer Nicolay
Published: February 2023

Climate change is one of the most pressing challenges to humankind today. The number and severity of wildfires are increasing in many parts of the world, with record-breaking temperatures, prolonged heat waves, and droughts. We can minimize the risks and consequences of these natural disasters by providing accurate and timely wildfire progression predictions through fire spread modeling. Knowing the direction and rate of spread of wildfires over the next hours can help deploy firefighting resources more efficiently and warn nearby populations hours in advance to allow safe evacuation.Physics-based spread models have proven their applicability on a regional scale but often require detailed spatial input data. Additionally, rendering them in real-time scenarios can be slow and therefore inhibit fast output generation. Deep learning-based models have shown success in specific fire spread scenarios in recent years. But they are limited by their transferability to other regions, explainability, and longer training time. Accurate active fire data products and a fast data pipeline are additional essential requirements of a wildfire spread early-warning system.In this study, physical models are compared to a deep learning-based CNN approach in terms of computational speed, area accuracy, and spread direction. We use a dataset of the 30 largest wildfires in the US in the year 2021 to evaluate the performance of the model’s predictions.This work focuses in particular on the optimization of a cloud-based fire spread modeling data pipeline for near-real-time fire progression over the next  2 to 24 hours. We describe our data pipeline, including the collection and pre-processing of ignition points derived from remote sensing-based active fire detections. Furthermore, we use data from SRTM-1 as topography, ESA Land Cover and Corine Land Cover for fuel composition, and ERA-5 Reanalysis products for weather data inputs. The application of the physics-based models is derived from the open-source library ForeFire, to create and execute physical wildfire spread models from single fire ignition points as well as fire fronts. The predictions of the ForeFire model serve as a benchmark for the evaluation of the performance of our Convolutional Neural Network. The CNN forecasts the fire outline based on a spatiotemporal U-Net architecture. The scaling of the algorithms to a global setting is enabled by the Leibniz Supercomputing Centre. It enables large-scale cloud-based machine learning to provide a time-sensitive solution for operational fire spread modeling in emergency management based on real-time remote sensing information. 
Adapting with future increases to coastal and riverine flood risk in deltas and estuaries: a global perspective
Authors: Mortensen Eric , Ward Philip
Published: February 2023

Deltas and estuaries concurrently represent some of the most delicate natural environments and highly populated regions of the world. Due to climate change, among other global and local variables (e.g., urbanization, land subsidence, etc.), these areas face unprecedented increases to flood risk over the next several decades. A large portion of total future coastal flood risk is found in the world's deltas and estuaries, while overall global riverine flood risk exhibits more expansive spatial distribution. Still, the presence of high levels of potential human and monetary impacts due to these two types of flooding presents a unique challenge for decision makers worldwide. For these areas of the world to survive, disaster risk reduction action is needed in the form of adaptation. Our work shows the adaptations options for a selection of critical deltas and estuaries throughout the world. We model dykes and levees (structural hazard reduction), saltmarsh preservation and mangrove restoration (nature-based hazard reduction), dry-proofing of urban assets (vulnerability reduction), and zoning restrictions on future urban development (exposure reduction), and quantify the costs and benefits of these adaptation measures. Certain adaptation measures are better suited for some cases depending on the income level, environmental characteristics, and spatial population distribution of the region in question. For example, in the Ganges delta, expanding mangrove forests proves to be the most cost beneficial adaptation strategy. Meanwhile, restricting future urban development away from floodplains in the Congo estuary shows the most potential for flood risk reduction due to large amounts of projected population growth. And highly urbanized deltas and estuaries, such as the Mekong and the Hudson, demonstrate potential risk reductions via widespread dry-proofing. With this work, we are able to identify specific adaptation pathways forward into the future for these crucial areas of the world, while also opening the dialogue for related topics, such as compound flood risk and adaptation hybridization.
Monitoring and Data Quality Issues of Mining Activites Around BRTR, Turkiye
Authors: Destici Cem , Şemin Korhan , Koçak Serdar , Özener Haluk
Published: February 2023

Bogazici University-Kandilli Observatory and Earthquake Research Institute (KOERI) is operating IMS Primary Seismic Station (PS-43) under Belbasi Nuclear Tests Monitoring Center for the verification of compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) since February 2000. PS-43 is composed of two seismic arrays (Ankara and Keskin). The medium-period array equipped with Guralp CMG-3TB instruments is located in the capital city of Ankara whereas the short-period array with Geotech 23900 sensors is located in Keskin. The data quality of the some of the array elements are degraded by the quarry blasts especially if there is an earthquake occurred at the same time with the explosion. There are more than 10 operational stone quarries spread across the city and there are more applications for new quarries each year. In this study, we show the importance of monitoring the quarry activities for the operation of the Turkish NDC. For this purpose, each blast is detected by automatically using cross-correlation and confirmed manually by the analyst.
Impact of orography on sub-daily precipitation upper tail from convection-permitting climate model simulations: a multi-model ensemble perspective
Authors: Correa Sánchez Nathalia , Dallan Eleonora , Marra Francesco , Fosser Giorgia , Borga Marco
Published: February 2023

Understanding the impact of orography on the probability distribution of extreme precipitation at short (i.e., sub-daily) temporal scales, as well as on extreme-rainfall causative processes, is critical for managing risk from rainfall-triggered natural hazards in mountainous regions. High-resolution convection-permitting models (CPMs) are crucial for this type of analysis since they better represent convective processes key to short-duration extremes. Here, we assess the ability of multi-model CPM ensemble CORDEX-FPS to represent the upper tail of sub-daily precipitation in a complex-orography region in the Eastern Italian Alps. In this area, different orographic impacts on sub-daily precipitation upper tail were reported at different event durations, and significant temporal trends in precipitation intensity were reported during the last few decades, making it a challenging and interesting test case for CPM simulations. An ensemble of six CPMs with a horizontal grid spacing of ∼2.2 km, driven by ERA-Interim reanalysis, are analysed and evaluated against ∼180 rain gauges. Since CPM simulations are too short (10 years) for analysing extremes using conventional methods, we use a non-asymptotic statistical approach (Simplified Metastatistical Extreme Value, SMEV), which was proven to provide reliable results even using short time records. We explore how the model spread vary with elevation and the ability of the multi-model mean to reproduce the distribution parameters and the extreme quantiles up to 100-year return period at different elevations.
High-resolution magnetic investigation of hydrothermal circulation in the Danakil Depression
Authors: Choe Hanjin , Mege Daniel , Dyment Jerome
Published: February 2023

The Danakil Depression is an active divergent boundary opening between the southern Red Sea rift and the Afar triple junction at a rate of ~1 cm/yr. Despite its geological interest, it is becoming increasingly difficult to study due to regional political instability and extreme environment. Our study area, located between the Erta ‘Ale volcano and Dallol, exhibits thick salt layers and iron-rich clay intercalations locally covered by mud volcanism deposits. The heat from the volcanic rift segment and the occasional influx of saltwater from Lake Karum create a unique hydrothermal system on land. In 2019 we collected ground magnetic field data around the main active hydrothermal fissure to investigate the magnetic signature of this hydrothermal system.  Our data show a clear linear magnetic anomaly low associated with the fissure, indicating a loss of magnetization due to the active hydrothermal activity. Local anomaly lows are observed at hydrothermal pools and in areas of subsurface bubbling. Apart from the hydrothermal areas, a relatively uniform magnetic anomaly is observed above the resurfaced reddish mud. Its slow decay away from the fissure may correspond to the progressive attenuation of the superficial iron-rich mud layer considered the most likely coherent magnetized source in the area. Our inference of the iron-rich mud layer as the bearer of a coherent magnetization that is altered by the hydrothermal activity needs however to be confirmed by sample analyses.
Insights into slab detachment dynamics from 0D to 3D numerical experiments
Authors: Piccolo Andrea , Thielmann Marcel , Spang Arne
Published: February 2023

Slab detachment is a process that has been invoked to explain rapid uplift, deep seismicity and magmatic activity in several active orogens (e.g., Alps, Himalaya). The negative buoyancy force associated with a slab at depth and its progressive removal during detachment results in a reorganization of forces within the lithosphere and the detaching slab. However, it is not yet clear to which extent slab detachment is the primary cause of the different observations. Deciphering the impact of slab detachment on the observations mentioned above therefore requires a thorough understanding of the physical processes controlling deformation within and around the detaching slab. 

Here, we employ numerical models to investigate the nonlinear coupling between mantle flow and slab detachment. Due to the three-dimensional nature of slab detachment and the variety of involved processes, it is difficult to pinpoint the first order controls on the time scale of this process. As a first step, we therefore develop a simplified 0D necking model that describes the temporal evolution of the thickness of a detaching slab, additionally taking into account the effects of the nonlinear coupling between upper mantle and detaching slab. This allows us to derive a set of nondimensional numbers which ultimately control the slab detachment process.  

Based on these findings, we then use 2D and 3D numerical models to further determine higher dimensional geometrical effects on slab detachment. Results show that the predictions from the 0D experiments predict the 2D and 3D experiments sufficiently well if simple slab geometries are used. For more complex slab geometries, higher dimensional results deviate from the 0D predictions. Nevertheless, the combination of 0D and 2D/3D numerical models allows to efficiently determine first order controls on slab detachment and thus also on specific geological observations such as seismicity and surface response. 
Ensemble Design: Sensitivity Beyond Initial Values
Authors: Stainforth David A.
Published: February 2023

Climate change is a complex, multidisciplinary problem which relates our physical understanding of the consequences of greenhouse gas emissions with economic and socio-political actions to mitigate and adapt to those consequences. An important role that the mathematics of climate change can play involves utilising and developing understanding of nonlinear systems in such a way as to guide the design of ensembles of Global Climate and Earth System Models (ESMs), as well as integrated assessment and economic models. To this end it is informative to view these computer models as high-dimensional nonlinear systems and ask what we can learn about ensemble design from somewhat related, low-dimensional nonlinear systems. This talk will discuss what it means to make a prediction of climate change within a computer model as well as how we can design ensembles to reflect our uncertainty in the real-world, physical climate system. The Lorenz ’84/Stommel ’61 (L84-S61) system will be introduced as a valuable tool for studying issues of ensemble design and will be used to illustrate key sources of uncertainty and sensitivity. First amongst these senstitivities is initial value sensitivity of the sort explored in a variety of single model large ensembles (see session CL4.10/NH11/OS4) - these are known as micro-initial-condition ensembles. However, the results of such ensembles can themselves be dependent on large scale features of the starting conditions - so-called macro-initial-condition uncertainty. Lastly, the sensitivity of ensemble results to model structure and parameter value selection is crucial. How can we identify how close to the target system a model has to be to make useful probabilistic forecasts at different lead times? This question raises the prospect that climate predictions could be vulnerable to the “hawkmoth effect” - the potential for probabilistic forecasts based on initial condition ensembles to be highly sensitive to the finest details of model formulation. Here the different types of initial value and model parameter sensitivities will be illustrated with the L84-S61 system. Based on these, a series of design questions will be raised - questions which suitably-designed ensembles of low-dimensional systems could help us understand and answer, and which could be extremely valuable in improving the design of ensembles of GCMs and ESMs.
Cirrus clouds in the tropical tropopause layer observed at Koror, Palau (7.34°N, 134.47°E)
Authors: Sun Xiaoyu , Palm Mathias , Ritter Christoph , Notholt Justus
Published: February 2023

A Compact Cloud and Aerosol LIDAR (ComCAL) is operated in Koror, Palau (7.34°N, 134.47°E) since 2018. Palau is located in the Pacific warm pool, which plays an important role in global stratosphere-troposphere exchange in the upper troposphere and the lower stratosphere (UTLS). ComCAL is operated during nighttime, carried out observations of atmospheric profiles of aerosols and clouds, and the lidar profile extends from 8 km to 30 km. Cirrus clouds were detected with very high occurrence in the upper troposphere (above 12 km). The subvisible clouds (with an optical thickness of less than 0.3) often occur in the higher region of the tropical tropopause layer (TTL) above about 16 km which is close to the cold point. The transport of air in this layer with thin cirrus and subvisible clouds was investigated by the TRACZILLA Lagrangian model, a variation of FLEXPART. The back-trajectory analysis gives insight into the origins of cirrus clouds in the TTL whether it is related to the convection or the in situ uplifting of the air masses.
Archean Earth Climate Drivers
Authors: Taylor Anya , Wilmes Sophie-Berenice , Mayne Nathan , Way Michael , Green Mattias
Published: February 2023

The Archean Eon (4.0 - 2.5 Ga) is a very important time period: it spans roughly one third of Earth’s history, likely hosted the earliest lifeforms, and was critical for the development and long-term maintenance of a habitable climate and surface conditions on Earth. There are very few physical proxy records stretching all the way back to the Archean, meaning that early Earth climate research is centered on computer modeling with proxy data as validation. This kind of research has built a solid understanding of what atmospheric and surface conditions were like on Archean Earth, and now we can shift focus and investigate why the climate changed so drastically during this period. This project aims to identify the primary drivers of Archean climate change by completing a large parameter sweep with Isca - a highly configurable framework designed for idealized terrestrial planetary atmospheres. Working back from present day Earth, boundary conditions will be changed one at a time in order to isolate their specific role in the climate change over the Archean period. Simulations with interesting results will then be passed to ROCKE-3D, to further evaluate with a fully-coupled earth system model. The first suite of simulations will investigate the roles of three parameters that are intrinsic to Archean conditions: reduced solar luminosity, enhanced rotation rate, and a vastly different atmospheric composition. In later work more complexities will be added, and the role of land type, continental configuration, and orbital parameters (plus many more) will be investigated. The preliminary results of the initial suite of simulations will be presented here. By isolating the role of an extensive set of atmosphere, ocean, geologic, and orbital parameters using a simple model framework, we hope to identify the primary drivers of Archean climate change. This will help to quantify the relative importance of each variable in terms of planetary habitability, and can potentially be extrapolated to benefit the search for habitable planets outside of our solar system. 