bluuebunny/crossref_metadata_2025 huggingface dataset:
Managerial perspectives on climate change and stock price crash risk
Authors: Jung Hail , Song Chang-Keun
Published: February 2023

Unprecedented climate change not only affects our health, but also poses a significant risk to the economic and financial systems. Limiting the global temperature rise at below 1.5 °C, as suggested by the Paris Agreement, has a significant effect on financial economics. Physical climate change, such as global warming and sea level rise, may directly reduce a firm's productivity. Climate change may also indirectly affect a firm's costs due to governmental sanctions and regulations, such as the emission trading scheme. Simultaneously, some firms strategically use climate change issues as opportunities. As climate change risks do not unidirectionally affect firms, it is important to understand how firms and managers perceive climate change effects. In this manner, we examine the effects of manager's perspectives on climate change on stock price crash risk. The analysis confirms that manager's climate change perspective is negatively associated with future stock price crash risk likelihood. Various channel tests show that investor attention and analyst coverage are potential channels through which a firm's climate change perspective improves financial stability and ultimately reduces crash risk. Our results are also robust to alternative climate change perspective measures.
Predicting fault stress level and stress drop using seismo-mechanical and statistical features derived from acoustic signals in laboratory stick-slip friction experiments and assesing feature importance via the derived models.
Authors: Caus Danu , Grover Harsh , H. Goebel Thomas , Kwiatek Grzegorz , Weigel Tobias
Published: February 2023

Earthquake prediction relies on identification of distinctive patterns of precursory parameters that might precede a large earthquake. However, these patterns are typically not reliably observed in the field. Laboratory stick-slip experiments provide an analog of seismic cycle observed in nature in fully controlled conditions with the associated Acoustic Emission (AE) activity reproducing basic characteristics of seismicity preceding and following the large lab earthquake. Recent laboratory studies showed that the deployment of Machine Learning/Artificial Intelligence techniques has lead to new state of the art results in lab earthquake prediction on smooth faults while using simple statistical features derived from raw AE signals and AE-derived catalogs. However, not enough work has been done on explainability of earthquakes preparatory process on rough faults by leveraging deep learning techniques. In this work we attempt to mitigate this gap and analyze/grade a pool of  explainable seismo-mechanical features through the eyes of neural networks.We used AE data from three laboratory stick-slip experiments performed in triaxial pressure vessel on Westerly Granite samples. Samples were first fractured at 75MPa confining pressure creating rough fault surfaces. The following stick-slip experiments were performed at constant displacement rate. The experimental procedure led to an extremely complex slip pattern composed of large and small slips of the whole surface, as well as the confined slips highlighted only with AE data and no externally measured slip. The AE catalog was used to extract temporal evolution of 16 seismo-mechanical and statistical features characterizing evolution of stress and damage in response to the axial stress change. The feature pool included clearly physically interpretable parameters such as AE rates, b-value, fractal dimension, AE localization, clustering and triggering properties, and features characterizing the variability of local stress field. We apply explainable AI techniques to identify what features are more important to forecast  axial stress and stress drop.  Our feature ranking and importance evaluation with the help of neural networks can serve as an indicator as to what research directions are more promising to take for further feature engineering efforts with an emphasis on explainability of earthquake phenomena.
Hisaki space telescope observations of the large oscillations of Martian hydrogen and oxygen upper atmospheres
Authors: Masunaga Kei , Terada Naoki , Yoshida Nao , Nakamura Yuki , Kuroda Takeshi , Yoshioka Kazuo , Suzuki Yudai , Nakagawa Hiromu , Kimura Tomoki , Tsuchiya Fuminori , Murakami Go , Yamazaki Atsushi , Usui Tomohiro , Yoshikawa Ichiro
Published: February 2023

Analyzing extreme ultraviolet spectra of the Martian upper atmosphere obtained from the Hisaki space telescope, we found anti-correlation between hydrogen (HI Ly-β) and oxygen (OI 1356 Å and OI 1304 Å) airglow brightness during one of the major regional dust storms in Mars Year 33 (Masunaga et al., 2022). Ly-β brightness gradually increased by a factor of 2 over the observation period (LS=213°–232°) while oxygen airglow temporarily decreased by a factor of 3 during the dust storm period. We also found that their brightness varied alternately with a periodicity of ~6–8 days. The magnitude of their periodic airglow variations was ~20–50% for the whole disk, and the periodicity was consistent with that of atmospheric waves observed by the Curiosity Rover on the surface of Mars. These results suggest that hydrogen and oxygen abundances in the Martian upper atmosphere are highly controlled by dust- and wave-couplings between the lower and upper atmosphere, possibly altering the efficiency of hydrogen and oxygen escape from Mars. ReferenceMasunaga, K., N. Terada, N. Yoshida, Y. Nakamura, T. Kuroda, K. Yoshioka, Y. Suzuki, H. Nakagawa, T. Kimura, F. Tsuchiya, G. Murakami, A. Yamazaki, T. Usui, and I. Yoshikawa, Alternate oscillations of Martian hydrogen and oxygen upper atmospheres during a major dust storm, Nature Communications, 13, 6609, 2022
Inverse transient analysis for detecting multiple branched pipeline segments in a reservoir pipeline valve system
Authors: Ko Dongwon , Lee Jeongseop , Kim Sanghyun , Park Suwan , Yu Jungwon , Kim Kwang-Ju , Jang In-Su
Published: February 2023

The managment of water distribution systems is important not only for reliable water conveyance considering water quality but also for effcient asset management of pipeline infrastructure. Abnormality detection is a critical issuefor pipeline management authorities. Unknown side branches and dead ends are detrimental to efficient pipeline operation. Hence, this sudy explores a general method for detecting multiple side branches in a pipeline system. The method of caracteristics was used to simulate the transient responses of a specific branch with or without branched elements. The isolated pressure response of each branch and the interference caused by different elements of the pipeline was subsequently identified. A nonlinear valve action maneuver was considered for water hammer generation using a polynominal equation during mathmatical modeling. Experimental pressure decay patterns for various pipeline structure combinations showed differences between the numerical model and real-life system, which were explained by unsteady friction. The detection and location of side branches was achieved by considering the phase pressure bounce for which the numerical and experiment results were consistent.
Drivers of spatial and temporal variability in savanna fire emission factors
Authors: Vernooij Roland , Eames Tom , Russel-Smith Jeremy , Yates Cameron , Beatty Robin , Evans Jay , Edwards Andrew , Ribeiro Natasha , wooster Martin , Strydom Tercia , Giongo Marcos , Borges Marco , Barradas Carol , Menezes Maximo , van Wees Dave , van der Werf Guido
Published: February 2023

Roughly half of global fire emissions originate from savannas, and emission factors (EF) are used to quantify the amount of trace gases and aerosols emitted per unit dry matter burned. It is well known that these EFs vary substantially even within a single biome but so far quantifying their dynamics has been hampered by a lack of EF measurements. Therefore, global emission inventories currently use a static averaged EF for the entire savanna biome. To increase the spatiotemporal coverage of EF measurements, we collected over 4500 EF bag measurements of CO2, CO, CH4 and N2O using an unmanned aerial system (UAS) and measured fuel parameters and fire severity proxies during 129 individual landscape fires. These measurements spanned various widespread savanna ecosystems in Africa, South America and Australia, with early and late dry season campaigns. We trained random forest (RF) regressors to estimate daily dynamic EFs for CO2, CO, CH4 and N2O at 500×500-meter resolution based on satellite and reanalysis data. The RF models reduced the difference between measured and modelled EFs by 60-85% compared to static biome averages. The introduction of EF dynamics resulted in a spatial redistribution of CO, CH4 and N2O emissions compared to the Global Fire Emissions Database version 4 (GFED4s) with higher emissions in higher rainfall savanna regions. While the impact from using dynamic EFs on the global annual emission estimates from savannas was relatively modest (+2% CO, -5% CH4 and -18% N2O), the impact on local EFs may exceed 60% under dry seasonal conditions.
Zoned and atoll garnet from the Slavonian Mountains (Croatia) and their significance for the evolution of a complex polymetamorphic terrane
Authors: Balen Dražen , Massonne Hans-Joachim
Published: February 2023

The area of the Slavonian Mountains in Croatia is considered as a natural laboratory for the study of metamorphic processes on polymetamorphic rocks formed during the pre-Variscan, Variscan and Alpine orogenies. Since most lithologies contain garnet, understanding of its growth is an important to unravel the polymetamorphic evolution. Garnet up to 200 µm in size with atoll texture were found in quartz- and mica-rich rocks that have experienced peak metamorphism at intermediate temperatures and pressures in the amphibolite facies. These atoll garnet-bearing rocks occur in the oldest metamorphic complex of the Slavonian Mountains at several localities and are restricted to highly foliated mica-schists and/or paragneisses composed of quartz (~20 vol. %), plagioclase (~40-50 vol. %), biotite (20-30 vol. %), garnet (2-3 vol. %) and opaque minerals.The observed atoll structures are practically restricted to larger garnet comprising a core, an intermediate cloudy zone composed of garnet and the minerals of the rock matrix (quartz, biotite, plagioclase) and a nearly inclusion-free rim. Smaller garnet with uniform texture and composition, which corresponds to that of the rim of larger garnet, also occurs. The core of the atoll garnet shows higher Ca contents than the rim (12-16 vs. 4-5 mol.% of grossular component), lower Fe contents (68-69 vs. 75-76 mol.% of almandine component) whereas Mg and Mn contents are similar. Furthermore, the three domains of the atoll garnet show almost regular outlines or crystallographic forms. Pseudosection modelling was used to reconstruct a preliminary and simplified P-T path, which is clockwise with maximum pressure conditions at ~1.0-1.2 GPa and temperatures of ~650 °C. However, it is likely that these conditions were followed by a significant pressure decrease accompanied by resorbtion of garnet. Shape of garnet core and cloudy zone, but also mineral phase relations, suggest a second stage of garnet growth, forming the rim, during another pre-Variscan stage of amphibolite-facies metamorphism at P-T conditions of 0.5 GPa and 530 °C. This interpretation resulted from in-situ monazite dating, yielding two mean ages at 522±6 and 473±11 Ma (2σ).Atoll-shaped garnets are uncommon and have been recognized in contrasting metamorphic environments worldwide. Several models have been proposed to explain their formation, including preferential dissolution of garnet cores by fluid infiltration, polymetamorphism, coalescence of subgrains, and kinetic control associated with rapid growth. Here, the formation of the atoll garnet is interpreted by the following processes: external fluid infiltration into the fine-grained rocks and element exchange between the core of primary small garnet grains and matrix, dissolution of the garnet core and later replacement by a new garnet during a subsequent metamorphic event.
Induction mechanism and optimization of tradable green certificates and carbon emission trading acting on electricity market in China
Authors: Feng Tian-tian
Published: February 2023

China has promised that CO2 emissions per GDP in 2030 would decrease by 60% to 65% than that in 2005, and proposed the goal of achieving carbon neutral by 2060. In order to fulfill these goals, Carbon Emissions Trading (CET) and Tradable Green Certificates (TGC) have been implemented in the power industry during the ‘13th five-year’ period. We firstly simulate the combined effects of TGC and CET on the electricity market from 2020 to 2026. Further, we build a policy synergy model to explore the optimization relationship between TGC and CET systems. The results show that, the power supply structure can be optimized under TGC and CET systems. The growth rate of CO2 emissions from the power industry will slow down, accelerating peaking CO2 emissions of the power industry. The national CO2 emissions reduction goal (1.185–1.037 tons /RMB 10,000 yuan by 2030) is expected to be achieved. There may be policy redundancy between TGC and CET systems. It is determined by how to set renewable energy objective and CET quota objective. Under multiple policy objectives, the key is to obtain the policy synergy intervals for staged optimization. Finally, we propose some suggestions on the improvement of TGC and CET mechanisms, and combined implementation and optimization of multiple emission reduction policies.
Drivers and inter-seasonal trends of nutrient losses from contrasting agricultural river catchments in Ireland and UK
Authors: Ezzati Golnaz , Mellander Per-Erik , Pulley Simon , Collins Adrian
Published: February 2023

Current multi-stressor pressures on water quality in agricultural catchments will be exacerbated by the more frequent occurrence of extreme weather events resulting in multi-stressor environments. Managing surface water under future climatic conditions will require adaptations and targeted mitigation strategies that consider individual catchment characteristics. Assessing the impacts of recent extreme weather events can allow for the better understanding of, and insight into, the key drivers of elevated pollutant losses and point to the possible future challenges for water quality management.As a part of the Irish EPA funded WaterFutures project, changes in the impact of climatic drivers on nutrient losses from field to small stream scale catchments of different typologies are being investigated using long-term and high-frequency water quality datasets. The trends of daily nitrate-N, and phosphorus (TP) concentrations and loads over 11 years were interrogated in two agriculturally-dominated catchments in Ireland, and in both a permanent pasture and arable field in the southwest UK (ca. 0.38– 12 km2). The trends in nutrient losses and the significance of discharge, precipitation, potential evapotranspiration (PET), soil moisture deficit, air temperature, and soil temperature, were investigated using Mann-Kendall Trend and Generalised Additive Model, respectively.Significant inter-seasonal trends were identified in both countries and similar fluctuations of nutrient concentrations and loads in October and November 2018 were observed following an exceptional summer drought. All study sites responded to daily rainfall exceeding 10mm, although in different ways due to the different site characteristics. The soil and air temperature in the two geographically-close Irish catchments revealed a significant upward trend from June to September. During this period, these two drivers, along with discharge and PET, were key drivers of N-losses in the well-drained and arable dominated catchment. The increasing trend of monthly average N-concentrations were significant in April and November (from 5.6 in 2009 to 8.9 nitrate-N mg L-1 in 2018, Kendall-tau= 0.424). On the other hand, a catchment dominated by poorly-drained grassland showed an increasing trend in TP concentrations during January, May, September, and October (from 0.79 in 2009 to 6.72 TP mg L-1 in 2020, Kendall-tau= 0.455). Here, changes in air temperature, precipitation, and discharge were the key drivers for P losses.Changing weather patterns, consequent changes in nutrient concentrations and load trends, and precipitation-discharge responses can be detected using long-term water quality records and should be considered for future climate smart mitigation strategies. 
Chemical Weathering in New Guinea since the Mid Miocene
Authors: Clift Peter , Mohtadi Mahyar
Published: February 2023

Chemical weathering of silicate rocks is a well recognized method by which carbon dioxide is removed from the atmosphere and fixed as calcium carbonates in the sedimentary record. For many years the long term cooling of the Earth during the Cenozoic has been linked to uplift, erosion and weathering of the Himalayas and Tibetan Plateau, however following scientific ocean drilling of the submarine fans in the Asian marginal seas it now seems that this region could not be responsible for cooling, at least during the Neogene. Although other factors such as burial of organic carbon and the rates of degassing during seafloor spreading may also be important, erosion and weathering of other regions may also be important in controlling global CO2 concentrations. In this study we focus on the role of New Guinea, the large (>2500 km long) orogen formed as Australia collided with Indonesia since the Mid Miocene. New Guinea comprises slices of arc and ophiolite rocks that are susceptible to weathering, and is located in the tropics where warm, wet conditions favor rapid weathering. Rainfall exceeds >4 m annually in the island center. Analyses of sediment from Deep Sea Drilling Project Sites 210 and 287 in the Gulf of Papua now allow the weathering and erosion history of the island to be reconstructed. A trend to more continental erosion since 15 Ma reflects uplift and erosion of tectonics slices of the Australian plate. At the same time chemical weathering shows increasing intensity, especially since 5 Ma, as proxied by major element ratios (K/Rb, K/Al) and clay minerals. Greater proportions of kaolinite point to more tropical weathering since the Mid Miocene. Trends to more weathering contrast with Himalayan records that show the reverse, and suggest that New Guinea may be an important component in controlling global climate in the past 15 Ma.
The role of poroelasticity and permeability barriers in governing the interplay between precursory slow slip and foreshocks
Authors: Ye Jiayi , Dal Zilio Luca
Published: February 2023

Ample observations attest to the importance of pore pressure dynamics and fault-zone fluid flow in producing earthquake swarms, foreshocks, and aftershocks. However, poroelasticity effects incorporating the two-way coupling of solid and fluid phases where pore-pressure evolves due to e.g. slip, dilatancy, and compaction, are rarely considered in simulations of fault slip. Here we study how coupled dynamics of frictional slip, pore pressure, permeability and porosity evolution control the occurrence of precursory slow-slip and foreshocks leading to the mainshock. We model fully dynamic seismic cycles with a newly-developed Hydro-Mechanical Earthquake Cycles (H-MECs) code where uniform velocity-weakening rate-and-state friction and a constant and far-field loading rate are applied on a 2-D anti-plane fault model embedded in a poro-visco-elasto-plastic medium. We also include the effect of permeability barriers, represented by regions of low permeability and high pore-fluid pressure with wavelengths similar to the nucleation length. Despite the relatively simple model setup, a complex fault behavior arises from the numerical experiments, including small seismic events, complete ruptures, as well as aseismic slip transients. Our results indicate that permeability barriers – where pore-fluid pressure is high – lead to fault creep, whereas foreshocks and mainshocks unzip from locked asperities with relatively lower pore-fluid pressure. We find that the ratio between the size of locked asperity and the wavelength of permeability barriers controls both the nucleation and propagation of aseismic creep, slow-slip transients, cascade of foreshocks, and full seismic rupture. Further numerical experiments accounting for both permeability enhancement due to fault slip and permeability reduction due to healing and sealing show that, once the permeability seals break, fluid is injected and redistributed through the fault zone, which diffuses primarily on-fault, thus leading to the nucleation of a complete rupture. As a result, permeability evolution and pore-fluid pressure variations modulate the ratio of seismic to aseismic moment release of seismic swarms. Our results, compared to observations, demonstrate that pore-fluid pressure evolution and poroelastic effects on- and off-fault play a critical role in the dynamism of earthquake swarms, as they control the stability of faults and whether slip is seismic or aseismic.
Occurrence and Transition Probabilities for two Weather Classification Systems over Germany
Authors: Schoeller Henry
Published: February 2023

Weather type classification is a well-established and thoroughly researched field of study in atmospheric sciences. One of its applications is the analysis of occurrence of and transitions between large scale synoptic types. This is typically done by calculating the moving average of, or estimating linear or polynomial fits to relative frequencies. The presented work points out the theoretical inconsistencies implied by such approaches and, instead, employs binomial and multinomial logistic regression for consistent estimation of long-term trends in occurrence and transition probabilities between synoptic types, while assuming first-order Markovian behaviour throughout. The methodological framework's functioning is demonstrated using two prominent examples of weather type classification schemes with regional focus on Germany and central Europe. Temporal refinement to seasonal and monthly level and aggregation into combined groups of classes allows for tracing of observed trends, providing a more comprehensive understanding of the systems investigated. The results, by and large, fit in well with expectations about circulatory changes suggested by research about global warming induced climate change and can be verified by existing research in some cases. Inspection of transition probability changes allows for differentiation between changes in occurrence probability caused by changes in the mean vs. changes in circulatory dynamics. Limitations and favourable implementational details of the approach are determined and the Wald Null test is recommended for assessing statistical significance.
Mid-Level Dry Air Intrusions over the southern Maritime Continent
Authors: Aslam Ashar , Schwendike Juliane , Peatman Simon , Birch Cathryn , Bollasina Massimo , Barrett Paul
Published: February 2023

Patterns in extreme precipitation across the Maritime Continent in Southeast Asia are known to be modulated by many processes, from large-scale modes of variability such as the Madden-Julian Oscillation and planetary waves, to finer-scale processes such as the diurnal cycle. Transient mid-level dry air intrusions are an example of a process not extensively studied over the Maritime Continent, which has the potential to influence rainfall patterns.  

Through Lagrangian trajectory and event composite analyses, we use a humidity metric which identifies mid-level dry air intrusions. These intrusions originate from upper-level disturbances along the subtropical jet. Mid-level cyclonic circulation anomalies northwest of Australia from December-February (DJF) intensify westerlies in the southern Maritime Continent, advecting dry air eastward. In contrast, mid-level anticyclonic circulation anomalies northwest of Australia from June-August (JJA) intensify southern Maritime Continent easterlies, advecting dry air westward. The resultant transport direction of associated air parcels is also dependent on the seasonal low-level monsoon circulation, and potentially convective entrainment.  

Dry air intrusions are found to be important in influencing low-level wind circulations and rainfall patterns in the southern Maritime Continent. Dry air suppresses rainfall over seas near to the southern Maritime Continent in both seasons. Further suppression matches intrusions trajectories, such as over southern Maritime Continent islands in DJF, and the Indian Ocean in JJA. In both seasons, there is enhanced rainfall to the east of the intrusion, where there is moist return flow to the extratropics.  
Increased intra-seasonal variability in Indian summer monsoon precipitation in a warming climate
Authors: Sandeep Sukumaran , Kumari Neelesh
Published: February 2023

The characteristics of Indian summer monsoon (ISM) precipitation have been changing in a warming climate. We examined the intra-seasonal variability of daily mean ISM rainfall over central India in 20 CMIP6 models. The daily precipitation variance is found to have increased in the last 20 years of SSP585 runs compared to the 1981 – 2000 period of historical all forcing simulations. The mean ISM precipitation also shows an increase in the same period. The future changes in seasonal mean precipitation and the intra-seasonal variance in daily precipitation with respect to the historical period are scaled with the corresponding change in the surface temperature over the ISM domain. The changes in the seasonal mean precipitation do not show any significant relationship with the surface temperature change. However, the changes in the daily variance of ISM precipitation scale linearly with the changes in temperature. These results suggest that the ISM precipitation will become more erratic in a warming environment.
Describing the ocean variability as an atmospherically-modulated oceanic "chaos"
Authors: Penduff Thierry
Published: February 2023

Mesoscale ocean turbulence is the best-known expression of Chaotic Intrinsic Variability (CIV), which spontaneously emerges from the unstable ocean circulation regardless of the atmospheric variability. Substantial amounts of CIV are also found up to the scale of basins and decades, potentially produced by large-scale baroclinic instability or resulting from spatiotemporal inverse cascade processes.A 56-year atmospherically-forced 50-member 1/4° large ensemble simulation of the global eddying ocean/sea-ice system has been performed to explore these phenomena using the NEMO model. We first show that the low-frequency large-scale (LFLS) CIV has climate-relevant imprints over most of the globe, is largest in western boundary currents and south of about 30°S, and competes with (and in certain zones exceeds) the atmospherically-forced ocean variability (AFV) in terms of amplitude.However, the separability of AFV and CIV is questionable in certain cases. Concepts from dynamical system and information theories are leveraged to avoid this separation, and to probabilistically describe the ocean variability as an atmospherically-modulated oceanic "chaos". The partly random character of multi-scale ocean fluctuations in the eddying regime questions the attribution of observed signals to sole atmospheric drivers, the turbulent ocean predictability and its potential influence in high-resolution coupled simulations.
Characterisation of Arctic Cirrus by Airborne Water Vapor and High Spectral Resolution Lidar
Authors: Wirth Martin , Groß Silke
Published: February 2023

Ice clouds in the Arctic are expected to have different radiative properties compared to mid latitude cirrus, because of the different humidity and temperature profile and also the prevalent aerosol loading in northern latitudes which govern their formation. During the late winter and early spring 2022 the HALO-(AC)3 campaign was conducted out of Kiruna (Sweden) to probe artic clouds with an airborne remote sensing payload. For this purpose, the German research aircraft HALO was equipped with a water vapor Differential Absorption Lidar (DIAL), a cloud radar, micro-wave radiometers, radiation measurements in the visible, near infrared and thermal region and a drop-sonde dispenser. A total of 25 flights where performed mainly over the sea between Svalbard and Greenland and up to nearly 90°N.The primary observable to study ice cloud formation is the relative humidity, which is not directly measurable by lidar, but can only be computed with the aid of additional temperature information. By comparison with a large number of dropsondes launched during flight, we will show that the temperature field from ECMWF IFS analyses and short-term forecasts provides sufficient accuracy to retrieve the relative humidity for ice cloud studies. Using this method we will analyse different scenarios of arctic cirrus formation: under stable artic conditions, during a warm air intrusion and while a cold air outbreak. An interesting special case is the modification of cirrus properties by the presence of an aerosol layer which is most probably composed of long range transported Sharan dust. 
Worldwide distributions and key properties of Blue LUminous Events (BLUEs) as detected by ASIM
Authors: Gordillo-Vazquez Francisco J. , Soler Sergio , Pérez-Invernón Francisco J. , Luque Alejandro , Li Dongshuai , Neubert Torsten , Chanrion Olivier , Reglero Victor , Pérez-Navarro Javier , Ostgaard Nikolai
Published: February 2023

The presence of transient corona discharges occurring in thunderclouds has been suspected for a long time. Thunderstorm coronas can be observed as Blue LUminous Events (BLUEs) formed by a large number of streamers characterized by their distinct 337 nm light flashes with negligible (or absent) 777.4 nm optical emission (typical of lightning leaders). The Modular Multispectral Imaging Array (MMIA) of the Atmosphere-Space Interaction Monitor (ASIM) has successfully allowed us to map and characterize BLUEs worldwide. The results presented here include a global analysis of key properties of BLUEs such as their characteristic rise times and duration, their depth with respect to cloud tops, vertical length and number of streamers. We present two different global annual average climatologies of BLUEs depending on considerations about the rise time and total duration of BLUEs worldwide [1-3].We found that around 10 % of all detected BLUEs exhibit an impulsive single pulse 337 nm light curve shape. The rest of BLUEs are unclear (impulsive or not) single, multiple or with ambiguous pulse shapes. BLUEs exhibit two distinct populations with peak power density < 25 μWm−2 (common) and ≥ 25 μWm−2 (rare) with different rise times and durations. The altitude (and depth below cloud tops) zonal distribution of impulsive single pulse BLUEs indicate that they are commonly present between cloud tops and a depth of ≤ 4 km in the tropics and ≤ 1 km in mid and higher latitudes. Impulsive single pulse BLUEs in the tropics are the longest (up to about 4 km height) and have the largest number of streamers (up to approximately 3 × 109). [1] S. Soler, F. J. Pérez-Invernón, F. J. Gordillo-Vázquez, A. Luque, D. Li, A. Malagón-Romero, T. Neubert, O. Chanrion, V. Reglero, J. Navarro-González, G. Lu, H. Zhang, A. Huang, N. Ostgaard.: "Blue optical observations of narrow bipolar events by ASIM suggest corona streamer activity in thunderstorms" (Editor's Hightlight), Journal of Geophysical Research - Atmospheres, vol. 125, 2020, doi: 10.1029/2020JD032708.[2] S. Soler, F. J. Gordillo-Vázquez, F. J. Pérez-Invernón, A. Luque, D. Li, T. Neubert, O. Chanrion, V. Reglero, J. Navarro-González, N. Ostgaard.: "Global Frequency and Geographical Distribution of Nighttime Streamer Corona Discharges (BLUEs) in Thunderclouds", Geophysical Research Letters 2021, 48, doi: 10.1029/2021GL094657.[3] S. Soler, F. J. Gordillo‐Vázquez, F. J. Pérez‐Invernón, A. Luque, D. Li, T. Neubert, O. Chanrion, V. Reglero, J. Navarro-González, N. Østgaard.: "Global distribution of key features of streamer corona discharges in thunderclouds". Journal of Geophysical Research: Atmospheres, vol. 127, 2022, doi: 10.1029/2022JD037535.
Long-term effects of tillage systems on soil health of silt loam soil in Lower Austria
Authors: Toth Marton , Stumpp Christine , Klik Andreas , Liebhard Gunther Carl , Mehdi-Schulz Bano , Strauß Peter , Strohmeier Stefan
Published: February 2023

Tillage is an important management practice that can be necessary to loosen the soil and allow for seeding and aims at enhancing productivity. However, the long-term effects of a particular tillage action on soil health depend on the local soil characteristics and differ amongst soils. The main aim of our study was to evaluate the possible effects of various physical, chemical, and biological soil quality indicators in dependence of three different tillage practices: Conventional Tillage (CT), Mulch Tillage (MT), and No-Till (NT). A long-term tillage experiment that started in 1994 in Mistelbach, Lower Austria, was comprehensively sampled in 2002 and 2021. The research attempts to fill the knowledge gap in the long-term soil health changes due to shifting conventional tillage. To evaluate the soil health changes over time, we assessed the impact of the three tillage practices on selected soil quality indicators in the 0-20 cm layer and below 20 cm, which we determined as being below the plowing depth. The "Soil Management Assessment Framework" (SMAF) procedure was applied to assess and compare the overall soil quality. Twenty-one indicators were selected to compare and evaluate the long-term effects of the three tillage systems (a.); fifteen indicators were used to investigate the temporal changes since the last monitoring (b.); thirteen indicators were selected to assess overall soil quality (c.). The study shows that the tillage practices and temporal conditions significantly affected soil organic carbon (SOC) content. The SOC amount in the 0-20 cm layer was twice as high under no-till (31.2 t/ha) compared to conventional tillage (15.3 t/ha). The SMAF reveals that NT increased SOC content and enhanced soil's physical indicators, such as available soil water, porosity, and coarse pores in the 0-20 cm layer. We found soil quality improvements with MT and NT in the 0-20 cm layer; however, the SMAF also indicates that the soil quality was better below 20 cm in 2021 compared to 2002, independent of the tillage practice. According to our results, conservation tillage practices (such as MT and NT) enhanced overall soil quality, particularly the physical (available soil water, coarse pores) and soil biological indicators, mainly SOC.
Geochemical Characteristics of the Kızıldere Geothermal System (Turkey) and a Case Study for Emission Reduction in the Kızıldere Geothermal Field
Authors: Tut Haklıdır Füsun , Şengün Çetin Raziye
Published: February 2023

The Kızıldere geothermal field, located in the eastern part of the Büyük Menderes Graben, is one of the most productive geothermal systems in Western Anatolia (Türkiye). Electricity production in the field, which began in 1984, is still ongoing with three flash type geothermal power plants.Four geothermal reservoirs with different rock compositions and geochemical characteristics have been identified in Kızıldere geothermal system. Steam production has changed over time from a shallow reservoir to the hottest deep reservoirs in the system. In the steam phase, CO2 is the dominant gas type in the Kızıldere geothermal system, with concentrations ranging from 98% to 99%. The 13C analyses revealed that the primary source of CO2 is Paleozoic aged metamorphics and that the origin of CO2 is primarily reservoir carbonate dissolution. The deep reservoir contains sulfate, sulfide minerals, dissolved sulfate, dissolved sulfide (HS-), H2S gas, and organic sulfur compounds. Sulfate in thermal waters could be caused by gypsum dissolution or the oxidation of sulfides such as pyrite and pyrrhotite.In this study, the possibilities of reducing H2S and CO2 emissions by chemical and biological methods were investigated, taking into account the characteristics of the Kızıldere geothermal system. For this purpose, field tests were carried out with 6 different solutions  and the selected bacteria to examine the reduction of non-condensable gases in the Kızıldere geothermal field.
Advanced techniques for the study of plant interactions with Fungi and other microorganisms in early environments
Authors: Strullu-Derrien Christine , Spencer Alan R.T. , Mitchell Ria , Kenrick Paul
Published: February 2023

Microorganisms are key to our understanding of early life on land, especially in terms of below-ground processes. In the fossil record, exceptionally preserved silicified systems are the best sources to document the diversity of Fungi and microorganisms and the roles that they played, including their interactions with plants. Continued advances in technology allow us to document these in unprecedent detail at sites like the Rhynie cherts (Scotland, UK), dating to 407 Ma, and the Grand Croix chert (Massif Central, France), dating to ca 307 ̶ 303 Ma. Techniques we used include Confocal Laser Scanning Microscopy (CLSM) and Laser-Induced Breakdown Spectroscopy (LIBS)-based imaging, among others.In the Rhynie cherts, plant-fungal associations and glomeromycotan spores have been observed as well as other diverse microorganisms colonizing the substrate. In modern vascular plants, endomycorrhizas are typically associated with roots, but most of the vascular plants at Rhynie were rootless, and endomycorrhizas developed in aerial axes. This is probably the plesiomorphic state for land plants. Data from Grand Croix demonstrate that by the end of the Carboniferous, endomycorrhizas had become associated with the root systems of trees. The evolution of the endomycorrhizal symbioses during the Paleozoic, from early plants to trees, is associated with important changes in the nature of the symbiosis, the structure of the soil, and changes in level of carbon dioxide gas in the atmosphere. Using a combination of techniques to decipher the nature of the organisms and their interactions is as an area of developing interest, particularly in the context of recent work on modern relatives.   
Long-term fertilization and PFM changed the accumulation of stalk-derived POM in soil aggregates under field conditions
Authors: Jin Xinxin , Bol Roland , An Tingting , Zheng Lihong , Li Shuangyi , Pei Jiubo , Wang Jingkuan
Published: February 2023

Plastic film mulching (PFM) is critical for agricultural planting and production in semi-arid and arid areas. Particulate organic matter (POM) is assumed to be a sensitive indicator of evaluating the effects of different agricultural practices on soil fertility and soil organic carbon (SOC) pool. Soil aggregates are the main storage sites for POM. However, there is limited information regarding how PFM and fertilization influences the dynamic changes of newly added stalk-derived POM in Brown earth. Consequently, a depth-study of the fate of carbon (C) and nitrogen (N) derived from maize stalk residues as the POC and PON fractions in soil aggregates will help in predicting the active organic matter component sequestration in the soil. The dynamics and contribution of the newly added maize stalk C and N as POC and PON in different soil aggregates (using dry sieving method divided to > 2, 1-2, 0.25-1and < 0.25 mm) was analyzed by an in-situ 13C15N-tracing technique under 27-year long term PFM and different fertilization treatments. Over the 360 d cultivation, the POC and PON contents were significantly (P < 0.05) higher in the nitrogen (N) and organic manure (M) treatments than other fertilizer addition treatments. Compared with no PFM, PFM accelerated the decomposition of maize stalk C in the N fertilizer treatment, exhibiting an increase of 64% in stalk-derived POC in the initial cultivation time. In addition, stalk-derived POC tended to accumulate in 1-2 mm aggregates in the summer and fall as a result of long-term PFM coupled with fertilization. However, the stalk-derived PON was decreased with the cultivation time in different four aggregates. Stalk-derived POM was tended to accumulate in the macroaggregate size fraction (> 0.25 mm) over 360 days of cultivation in the field conditions. Accordingly, PFM application and fertilization practices had important effects on accumulation of newly added stalk-derived POM in soil aggregates.
The climate-vegetation interactions and subsequent hydrological effect of a subtropical forested watershed, central Taiwan
Authors: Chang Chung-Te , Lee Jun-Yi , Chiang Jyh-Min , Wang Hsueh-Ching , Huang Jr-Chuan
Published: February 2023

Vegetation growth is sensitive to climatic variations which has a critical implication for hydrological regimes. However, the intertwined associations of climate-phenology-hydrology have rarely been explored in tropical/subtropical regions particularly. In this study, we synthesize hydroclimate records in forested watershed, central Taiwan for last five decades (1975-2020), and the results indicate that the incidences of meteorological and hydrological droughts are becoming prominent after 2001. We further examine the influences of temperature and precipitation on vegetation growth of watershed scale using EVI (enhanced vegetation index) derived from MODIS (Moderate Resolution Imaging Spectroradiometer) at monthly scale, and explore the effects of seasonal precipitation on the variations of landscape phenology and following watershed streamflow between 2001 and 2020. The EVI and temperature shows a linear relationship (R2 = 0.50, p < 0.001) without time-lag effect, whereas EVI and precipitation exhibits a log-linear relationship with two months lag (R2 = 0.40, p < 0.001), showing the accumulative rainfall during relatively dry period (winter-spring) is crucial for vegetation growth. Structural equation modeling reveals that earlier start of growing season (SOS) caused by relatively high spring rainfall (February-March) leads to longer growing season (LOS) and higher P-Q deficit (precipitation minus runoff) during the growing season. Nevertheless, the large amount of precipitation during growing season has no effect on the end of growing season (EOS), LOS and P-Q deficit. Realizing the vegetation growth responding to climatic variations is necessary for current and future hydrologic regime, especially under changing climate.
Inferring reservoir filling strategies under limited data availability using hydrological modelling and Earth observation: the case of the Grand Ethiopian Renaissance Dam (GERD)
Authors: Mohammed Ali Awad , Melsen Lieke , Teuling Ryan
Published: February 2023

The filling of the Grand Ethiopian Renaissance Dam (GERD) started in 2020, posing additional challenges for downstream water management in Sudan, which is already struggling to cope with the effects of climate change. This is also the case for many transboundary rivers that observe a lack of cooperation and transparency during the filling and operation of new dams. Without information about water supply from neighbouring countries, it is risky to manage downstream dams as usual and operation information is needed to apply modifications. This study aims to test the applicability of using lumped hydrological modelling coupled with remote sensing data in retrieving reservoir filling strategies in regions with limited data availability. Firstly, five rainfall products (namely; ARC2, CHIRPS, ERA5, GPCC, and PERSIANN-CDR) were evaluated against historical measured rainfall at ten stations. Secondly, to account for input uncertainty, the best three performing rainfall products were forced in the conceptual hydrological model HBV-light with potential evapotranspiration and temperature data from ERA5. The model was calibrated during the period 2006 - 2019 and validated during the period 1991 - 1996. Thirdly, the parameter sets that obtained very good performance (NSE > 0.75) were utilized to predict the inflow of GERD during the operation period (2020 - 2022). Then, from the water balance of GERD, the daily storage was estimated and compared with the storage derived from Landsat observations to evaluate the performance of the selected rainfall products. Finally, three years of GERD filling strategies were retrieved using the best-performing simulation of CHIRPS with RMSE of 1.7 billion cubic meters (BCM) and NSE of 0.77 when compared with Landsat-derived reservoir storage. It was found that GERD stored 14% of the monthly inflow of July 2020, 41% of July 2021, and 37% and 32% of July and August 2022, respectively. Annually, GERD retained 5.2% and 7.4% of the annual inflow in the first two filling phases and between 12.9% and 13.7% in the third phase. The results also revealed that the retrieval of filling strategies is more influenced by input uncertainty than parameter uncertainty. The retrieved daily change in GERD storage with the measured outflow to Sudan allowed further interpretation of the downstream impacts of GERD. The findings of this study provide systematic steps to retrieve filling strategies for data-scarce regions, which can serve as a base for future development in the field. Locally, the analysis contributes significantly to the future water management of the Roseires and Sennar dams in Sudan. 
Overview of results from active source seismic reflection and refraction surveys acquired in the Swedish Caledonides and vicinity
Authors: Juhlin Christopher
Published: February 2023

The first larger scale seismic refraction survey over the Swedish Caledonides appears to date back to 1969 as part of the Trans-Scandinavian Deep Seismic Sounding project (Vogel and Lund, 1970). Forty-two receiver locations were occupied between Sundsvall and Trondheim with shot points off the coast of western Finland and in the water near Trondheim. Interpretation of P-wave arrivals and modeling showed a crust that is generally 40-45 km thick below the Baltic Shield, but that thickens some kilometers below the mountain belt, a result consistent with more modern interpretations (c.f. England and Ebbing (2012)). Since then a significant number of additional refraction surveys have been performed over the Swedish Caledonides, as well as larger scale reflection seismic surveying. The Collisional Orogeny in the Scandinavian Caledonides (COSC) reflection profile played a significant role in the siting of the two ICDP boreholes, COSC-1 (2.5 km deep) and COSC-2 (2.275 km deep) that were drilled in the mountain build in 2014 and 2020, respectively. Results from earlier active source seismic experiments will be reviewed in this presentation, as wells as more recent results from the COSC project. Vogel A. and Lund C.-E., 1970. Combined Interpretation of the Trans-Scandinavian Seismic Profile, section 2-3. Internal Report No. 4, Dept. of Solid Earth Physics, Uppsala University, 25pp.England R.W. and Ebbing J. 2012. Crustal structure of central Norway and Sweden from integrated modelling of teleseismic receiver functions and the gravity anomaly. Geophys. J. Int., 191, 1–11.