bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydro-electrical potential at risk und climate change: the case of Lake Malawi basin and the Shire River in Malawi / Southeast Africa
Authors: Bronstert Axel , Mtilatila Lucy , Vormoor Klaus
Published: March 2024

The hydroelectrical potential is derived from the hydraulic head and the available water discharge. In certain hydroclimatic regions, the water discharge is only a small part of the regional precipitation and the water cycle. This is particularly true when evaporation accounts for a large proportion of the regional water balance. Such conditions prevail, for example, in the catchment area of Lake Malawi and the Shire River in Malawi in south-east Africa. The country produces over 95% of its electricity from hydropower plants in the Shire River. This river is the outlet of Lake Malawi. Our study examines the sensitivity of regional water resources and hydropower generation to climate change, covering various aspects:Processing of rainfall, runoff and evaporation data for this tropical region, with particular attention to data scarcity.
Hydrological simulation of the water balance and water level of Lake Malawi as well as runoff.
Calculation of possible hydropower generation in the Shire River.
Performing scenario calculations for climate change conditions and associated sensitivity analyses.
The most important results of these analyses areBetween 1970 and 2013, meteorological droughts have increased in intensity and duration. This can be attributed to a decrease in precipitation and an increase in temperatures and evaporation rates.
The hydrological system of Lake Malawi reacts to meteorological droughts with a time lag (up to 24 months), so that hydrological droughts can be predicted up to 10 months in advance by meteorological drought parameters.
Despite the uncertainties in the regional climate projections, it is clear that the water level of Lake Malawi, as a residual of the catchment water balance, is very sensitive to changes in precipitation and evaporation.
The discharge from the lake is a direct function of the lake's water level, and the combination of the projected decrease in precipitation and increase in temperature leads to a significantly lower flow in the Shire River.
This suggests a future decline in annual hydropower production of between 1 % and 2.5 % (2021-2050) and 5 % and 24 % (2071-2100)
Some projections even result that the outflow of Lake Malawi would temporarily dry up and the country's electricity supply would be interrupted.
It is shown that regional evaporation and its changes are the key variable for assessing future water availability. This process is characterized by a particularly high degree of uncertainty.
The example of Lake Malawi basin shows that a careful hydro-climatic analysis is required to assess such sensitive hydro-systems. Global-scale analyses do not have sufficient predictive power and explanatory potential.
Analyzing 23 years of warm-season derechos in France: a climatology and investigation of synoptic and environmental changes
Authors: Fery Lucas , Faranda Davide
Published: March 2024

Derechos are severe convective storms known for producing widespread damaging winds. While less frequent than in the United States of America (USA), derechos also occur in Europe. The notable European event on 18 August 2022 exhibited gusts exceeding 200 km h-1, spanning 1500 km in 12 hours. This study presents a first climatology of warm-season derechos in France, identifying thirty-eight (38) events between 2000 and 2022. Similar to Germany, derechos in France are associated with a southwesterly circulation and display comparable frequencies. While a suggestive trend of higher late-season frequency and a potential larger proportion of low-intensity events in France are observed, caution is warranted due to the lack of statistical significance arising from a relatively small sample size. The study also examines synoptic and environmental changes linked with analogues of the 500 hPa geopotential height patterns associated with past warm-season derechos, comparing analogues from a relatively distant past (1950–1980) with a recent period (1992–2022). For most events, a notable increase in convective available potential energy (CAPE) is observed, consistent with Mediterranean trends. However, there is no consistent change in 0–6 km vertical wind shear in the recent period. These environmental shifts align with higher near-surface temperatures, altered mid-level atmospheric flow patterns, and often, increased rainfall. The role of anthropogenic climate change in these changes remains uncertain, given potential influences of natural variability factors such as the El Niño Southern Oscillation (ENSO) or the Atlantic Multidecadal Oscillation (AMO).
Tropical Cyclone Rainfall Asymmetries Inferred from GPM-IMERG: A Focus on Lesser Antilles
Authors: Nabukulu Catherine , Ettema Janneke , Jetten Victor , van den Bout Bastian
Published: March 2024

AbstractThis study utilizes GPM-IMERG satellite rainfall estimates to assess the asymmetric rainfall patterns in 27 tropical cyclones (TCs) across the Lesser Antilles region from 2000 to 2020. The aim is to evaluate whether there is a persistent relationship between precipitation and wind characteristics, which could support improved TC-related flood risk assessment for these islands. With a focus on hurricane and tropical storm categories, the 30-minute precipitation variability was assessed within a radius of 500 km from the TC’s eye during its path in the study area. In addition, TC’s forward speed and wind characteristics, like  TC’s category and the extent of 34-knot winds (R34), are included. The analysis reveals temporal trends, indicating increased TC rainfall events in the study area during the second decade. Correlations show positive relationships between rainfall total (RT), rainfall area (RA), and rainfall intensity at the 90th percentile (RI0.9), with RT and RI0.9 showing the strongest link in the majority of the observations. Contrary to conventional assumptions, this research challenges the idea that highest category TCs in the wind intensity always produce higher rainfall, as we see that higher-category hurricanes such as H4 (209-251km/hr) and H5 (>=252km/hr) were often associated with lower rainfall values in RT and RI0.9 compared to tropical storms (63 - 118 km/hr). Tropical storms, like higher-category hurricanes, can display large rainfall areas. In addition,  quadrant analysis of rainfall zones around the TC eye highlights that the NE and SE quadrants in TC have significantly more rainfall impact. However, it also reveals the danger posed by weaker quadrants in wind characteristics such as SW and NW, as they can exhibit high rainfall values in RA and RT. The study indicates complex, non-linear relationships between TC’s wind and precipitation characteristics in the Lesser Antilles region. Incorporating the rainfall variability observed in TC dynamics into early warning systems and risk assessment is essential for a more effective emergency response and mitigation planning.General methodologyThe satellite rainfall estimates were obtained within a defined buffer of a diameter of 500km around the TC eye while following the TC trajectory. The buffer was further dissected into quadrant spatial zones  (NE, SE, SW and NW) to provide a detailed perspective on rainfall distribution in different parts of the TC impact area. For each eye position, rainfall characteristics (RT, RA and  RI0.9) were computed for the whole buffer and later individual quadrant partitions. The computed rainfall characteristics were then investigated for potential correlation relationships with the TC wind intensity. In addition, quadrant rainfall patterns were analyzed for persistence throughout the TC duration. 
Surface Ozone Trends in South America: Unraveling the Influence of Precursor Shifts and Extreme Events
Authors: Seguel Rodrigo , Castillo Lucas , Opazo Charlie , Rojas Néstor , Nogueira Thiago , Cazorla María , Gavidia-Calderón Mario , Gallardo Laura , Garreaud René , Carrasco Tomás , Elshorbany Yasin
Published: March 2024

This work analyzes ground-level ozone trends in South America, an understudied region with scarce comprehensive trend estimates. We present an updated regional analysis and test a hypothesis proposing that the recent increase in ozone levels, particularly in urban environments, may be linked to intense wildfires induced by extreme meteorological events within a preexisting volatile organic compounds (VOC)-limited regime. Utilizing the quantile regression method, we estimate trends, quantify uncertainties, and identify change points. Short- and long-term exposure is assessed using the maximum daily 8-hour average and peak season metrics. Our findings reveal lower ozone levels in tropical cities (Bogotá and Quito), ranging between 39-43 ppbv for short-term and 26-27 for long-term exposure. In contrast, extratropical cities (Santiago and São Paulo) exhibit higher ozone levels, with short-term exposure at 61 ppbv and long-term exposures between 40-41 ppbv. Santiago (since 2017) and São Paulo (since 2008) show positive trends of 0.6 ppbv yr-1 and 0.2 ppbv yr-1, respectively, with very high certainty. We attribute these upward trends, or the absence of evidence of variation as observed in Bogotá and Quito, to the established VOC-limited regime. However, the higher increase in extreme percentile trends (≥ 90th) is linked to the impact of wildfires and biomass burning, particularly in southwestern South America, associated with extreme meteorological configurations.
Investigating glacial weathering fluxes from West Antarctica across the Mid-Pleistocene: Insights from  Os isotopes
Authors: Goss Gryphen , Rooney Alan
Published: March 2024

The Mid-Pleistocene Transition (MPT) is a period marked by significant changes in the LR04 benthic δ18O record. During this interval (ca. 1.25-0.65 Ma), glacial cycles shifted from symmetrical 41-thousand-year (kyr) cyclicity to asymmetrical 100-kyr cycles. This transition was characterized by a number of large-scale ice sheets, including terrestrial-based ice sheets in the northern hemisphere (e.g.,  the Laurentide and Greenland ice sheets) and a marine-based ice sheet in the southern hemisphere (e.g., the West Antarctic Ice Sheet). Since these different ice sheets respond to climate variability in unique ways, the LR04  stack may fail to capture certain aspects of regional cryospheric behavior across the MPT. Specifically, a potential lag in ice-rafted debris (IRD) fluxes, hinting at possible bipolarity in glacial terminations. This study aims to investigate glacial weathering fluxes from West Antarctica across the MPT by constructing an osmium isotope chemostratigraphic record in conjunction with published IRD records from IODP site U1536 in Iceberg Alley, in the Scotia Sea. This record will be compared to a previously published record from the IRD Belt in the North Atlantic. By examining glacial weathering products in regions with high accumulation of glacially-derived debris, these two records will provide a comprehensive comparison of cryospheric behavior in the North and South Atlantic across the MPT. This new dataset will offer a more detailed perspective of global cryospheric behavior during the MPT and may reveal synchronicity between the two hemispheres.
The October 1787 Ebro flood: the biggest flood event of NE Iberian Peninsula in the last 500 years
Authors: Balasch Solanes Josep Carles , Barriendos Josep , Barriendos Mariano , Tuset Jordi , Pino David
Published: March 2024

The reconstruction of past flood episodes is of vital importance in the study of river dynamics for assessing the impact of climatic and environmental changes, and evaluating the risk of these disasters on current populations. The main objective of this study is to present a multidisciplinary analysis of the catastrophic flood episode that occurred in the Ebro River basin (85,000 km2) on 8th-9th October 1787.The methodology includes an extensive research from documentary sources of the damaged locations. By using this data, maps of the extent of the affected area and the temporal evolution of the event have been reconstructed. Then, utilizing the maximum water height (3 flood marks), numerical simulations of hydraulic and hydrological reconstructions have been carried out to obtain the peak flows and the amount of precipitation. The meteorological reconstruction utilizes daily barometric information collected at that time from different observatories in Western Europe to plot surface pressure maps to estimate wind direction and the location of the cyclonic centers.The results show that this is the most serious episode that has occurred in the northeast of the Iberian Peninsula the last 500 years. There were more than 500 fatalities in the Lower Ebro area, numerous homes and structures were destroyed and the regional economy was damaged for several decades. The affected area was mainly the eastern Ebro basin (with 31 documented points), but it also extended to small areas of coastal basins of the Llobregat and Júcar Rivers (9 affected points). After about 10-12 consecutive days of rain caused by two active low-pressure centers combined with an influx of moist air from the Mediterranean Sea, some of the largest peak flows that the Ebro River has experienced since the beginning of the 16th century occurred. These flows reach to 12,900 m3·s-1 of the Ebro River in Tortosa (mean flow: 428 m3·s-1), 4,500 m3·s-1 of the Ebro in Zaragoza (mean flow: 231 m3·s-1), 4,500 m3·s-1 of the Segre River in Lleida (mean flow: 80 m3·s-1) and about 2,500 m3·s-1 of the Cinca River in Fraga (mean flow: 78 m3·s-1). According to historical accounts, the origin of the flood is purely pluvial without contributions of snow melting in the Pyrenees.The specific peak flow of the Ebro in Tortosa (0.15 m3·s-1·km-2) exceed the flows of any large European river of the same basin size (Po, Danube, Rhine, Rhône). Therefore, we are facing an event of extreme magnitude that is essential to study and to explain fluvial variability and risk analysis.
Impact of multidecadal climate’ modes variability on the Northern Hemisphere temperature trend in the recent decades
Authors: Savita Abhishek , Joakim Kjellsson Joakim , Latif Mojib , Nnamchi Hyacinth , Wahl Sebastian
Published: March 2024

In recent decades, the Northern Hemisphere (NH) exhibits a long-term regional cooling (central Eurasia) and warming (Arctic and Northern America) trend caused by human-induced anthropogenic forcing and internal decadal variability. In this study, we quantify the contribution of internal decadal variability to recent NH temperature trend using an atmosphere general circulation model (OpenIFS) by designing some sensitivity experiments for the period 1950-2014. In the reanalysis dataset (ERA5), we find a significant teleconnection between Interdecadal Pacific Variability (IPV) and surface air temperature (SAT) over Eastern Eurasia, the Barents Sea, and the Kara Sea for the periods 1950-2014 and 1993-2014, whereas we have not seen such a significant teleconnection with Atlantic Multidecadal Variability (AMV). The model simulates temperature anomalies associated with the IPV consistent with the ERA5, except for northern Eurasia where the sign of the temperature anomaly is reversed compared to ERA5. The model simulates AMV teleconnection with SAT is positive and significant over most of the places during 1950-2014, and it is significant over central Asia during 1993-2014. By analyzing the sensitivity experiments, in which we removed the decadal variability associated with IPV and AMV, we find that Eurasian cooling significantly increases without IPV and there is not much change without AMV. This indicates that some of the recent cooling over the Eurasian region is not driven by the IPV at least in the OpenIFS model, which shows IPV contributes to warm the Eurasian region. The preliminary results of this study suggest the potential importance of the internal variability of the Pacific Ocean is not only crucial on a regional scale but also crucial on a on a hemispheric scale (high latitudes).
Unmanned Aerial Vehicles and Terrestrial Laser Scanning are used to Monitor Kshetrapal landslides in the Chamoli Hazard Areaof Upper Himalayan Region in Uttarakhand, India.
Authors: Anand Ashok , Bhardwaj Alok
Published: March 2024

The Himalayan belt includes the geologically unstable mountainous terrain of upper Uttarakhand, which is distributed throughout Sonprayag, Sitapur, Rampur, Barasu, Kalimath, Madhyamaheshwar, Chamoli, Birahi, Byasi, and Atali.There are many more mountain ranges in the region. The rains that fall during the monsoon season are the most common cause of landslides in this mountain chain, whereas earthquakes and aftershocks are the least common cause. Hill slopes are becoming unstable as a result of human involvement in nature,which includes activities such as cutting roads without following scientific principles, dumping garbage along roadsides, using landslide , deformation, and illegal mining operations, among other things. Once the prone regions have been identified and hazard zonation maps have been prepared, it will be possible to protect the different entitlements that are at risk due to the landslip threat.The current investigation is an inventory-based technique that makes use of satellite data in order to determine the grey regions that exist within the region. The topo sheets of India, the geological maps that are already in existence, the data from remote sensing, the historical landslip data from 2010 to 2023, and the field inspection were all done. It is possible to construct primary topographic data with the use of a Digital Elevation Model (DEM), which includes aspects, slopes, curvatures, hill shades, mean curvatures, plan curvatures, relief, and drainage density respectively.  Afterwards, a Landslip Hazard Zonation (LHZ) Map is created by superimposing several theme layers. This is done in order to facilitate the process of making logical decisions and to facilitate the implementation of mitigation measures in advance of an occurrence. The observed landslip is mostly composed of rock and boulder falls as well as debris flow. Within this complex network of mountain ranges, there are significant dynamic sites that need the attention of scientists for further investigation. The findings will be disseminated to catastrophe authorities and governmental organizations in order to facilitate the development of contingency plans for dealing with future occurrences.
Impact of Holocene environmental change on northern Adriatic populations of Echinocyamus pusillus
Authors: Bachmann Bettina , Nawrot Rafał , Zuschin Martin
Published: March 2024

The consequences of prolonged human stressors on populations of marine benthic species are generally difficult to assess due to the paucity of long-term monitoring data. The youngest fossil record, preserved in sediment cores and grab samples, provides a rich historical archive that allows tracking ecological responses to natural environmental changes and reconstructing the state of populations prior to the onset of anthropogenic impacts. However, most studies using these paleoecological records focus on microfossil- or mollusc assemblages, and only limited knowledge is available on the responses of other key components of marine ecosystems, such as echinoids. This study presents a novel record of well-preserved tests of the infaunal clypeasteroid Echinocyamus pusillus from Holocene marine sediment cores, which provide new insights into the long-term population dynamics and ecological responses of the widely distributed echinoid. We investigated trends in test size and abundance of E. pusillus and relate them to sedimentological conditions during the last ~11,000 years in the shallow northern Adriatic Sea, where coastal marine habitats have been under prolonged anthropogenic pressure. We combined these data with radiocarbon dating of multiple specimens to extract ecological signals from time averaged assemblages. The sediment cores and grab samples collected from four stations, which cover different benthic habitats, document environmental changes during the post-glacial transgression and the Holocene-Anthropocene transition, as evidenced by shifts in molluscan assemblages and geochemical proxy records. The data suggest significant fluctuations in E. pusillus abundance, but remarkably stable test sizes over the past millennia and across sampling stations. Moreover, the age-dating results indicate a paucity of dead tests originating from the late 19th and 20th centuries in the surface mixed layer. This points to a strong decline in test production and thus population densities over the past ~200 years. This pattern can be linked to pronounced environmental changes during the onset of the Anthropocene, including siltation, eutrophication, and increased frequency of hypoxic events. Rapid decline of populations during that time combined with temporal mixing of fossil assemblages may thus explain the overall lack of body size shifts observed in sediment cores. Our results provide a fundamental baseline for evaluating temporal and spatial changes in body size and abundance of E. pusillus in the northern Adriatic Sea. They can be compared with recent monitoring and fossil data from other areas and serve to disentangle natural population variability from responses to recent intensification of human impacts.
“Slow science” concept: first insights of perceptions and suggestions in an oceanography laboratory
Authors: Barbot Simon , Roullet Guillaume , Serazin Guillaume
Published: March 2024

In the attempt to look back on our practices and to plan their evolution, a debate has been conducted in our lab to share the different perceptions about the “slow-science” concept. This debate surprisingly gathered more curiosity than expected and all profiles of scientists were represented from the BSc, PhD students and engineers to emeritus researchers. Suggestions have been made for future practices that would increase the quality of the scientific results and knowledge as well as better working conditions while reducing green gas emission. A generational inequity was pointed out to initiate the changes: early-career researchers are selected based on project-and-paper-productive metric, while established researchers have positions of influence throughout institutions. Although such changes would need institutional decisions and technical innovation for lowering the measurement’ impact, many suggestions are already feasible through hindsight and self-discipline.
Revealing the plausible areas for rainwater harvesting and groundwater abstraction for the accomplishment of sustainable development purposes in arid regions 
Authors: Abdelkareem Mohamed , M. Mansour Abbas , Akawy Ahmed
Published: March 2024

Climate changes cause droughts and storms in many places, impacting sustainable development. Water scarcity caused by climate change will be a significant obstacle to climate adaptation and sustainability. Therefore, rainfall harvesting is becoming a significant approach in arid regions that suffering from water scarcity. Such an approach allowed for capturing and holding water resources in ponds, lakes, and groundwater aquifers needed to expand agricultural, urban, and industrial activities. In this project, radar and optical remote sensing data have been integrated with climatic, hydrologic, and geological data that successfully enabled the identification of potential water accumulation zones and optimum areas for rainwater harvesting. The processing of the SRTM, Sentinel-1&2, Landsat-8, TRMM, ALOS/PALSAR, and InSAR coherence change detection (CCD) data revealed geomorphic, structural, and hydrologic properties of the catchments and rainfall intensity zones of Wadi Safag which is a significant drainage system that drains into the Red Sea, Egypt. Several factors were combined, after assigning weights to each using a GIS-based knowledge-driven methodology. The results delineated the promising areas for rainfall harvesting and groundwater potential zones (GPZs). Additionally, the results identified the optimum areas for constructing lakes and dams to store rainwater and protect the mining, industrial, and tourism areas in the studied basin. Overall, identifying the probable areas for water accumulation and groundwater abstraction is crucial for planners and decision-makers for the achievement of sustainable development in Wadi Safaga, Egypt.
Timing and spatial extent of snow avalanches inferred from tree rings in Sureanu Mountains (Southern Carpathians, Romania)
Authors: Pop Olimpiu
Published: March 2024

Snow avalanches (SAs) are one of the debris transfer mechanisms that affect steep slopes of alpine and subalpine belts in the Carpathian Mountains. In remote areas of Carpathians where SA activity is poorly documented, the hazard assessment is hampered by the lack of information about past SA events. This is the case in Sureanu Mountains (Southern Carpathians, Romania), where archival records of the past SAs are missing. There is an urgent need for hazard zonation mapping, as in the last decades, recreational activities attracted an increasing number of tourists reaching the SA-prone slopes in this high mountainous area. This study aims to increase the knowledge on SA history by reconstructing SA events based on tree-ring records in five adjacent avalanche paths in Sureanu Mts. For this purpose, Norway spruce trees (Picea abies (L.) Karst.) exhibiting clear signs of mechanical disturbances caused by the past SAs were sampled. Growth anomalies (e.g., scars, tangential rows of traumatic resin ducts, compression wood and growth suppression sequences) were identified within the annual rings of disturbed trees and served to reconstruct spatial extent, frequency, and return periods of SAs within each of the investigated path. In forested areas of Sureanu Mts. without any monitoring, tree-ring methods allowed to reconstruct spatio-temporal activity of SAs with annual resolution. This information may significantly improve the knowledge of the avalanche regime and contribute to the avalanche hazard zonation in the studied area.
GHGSat’s constellation: Land and offshore greenhouse gases detection and quantification 
Authors: Strupler Mathias , Girard Marianne , Jervis Dylan , MacLean Jean-Philippe W , Marshall David , McKeever Jason , Ramier Antoine , Tarrant Ewan , Young David
Published: March 2024

GHGSat operates a growing constellation of small satellites tailored for high-resolution imaging and quantification of methane emissions, achieving ~25 m spatial resolution and a sensitivity down to ~100 kg/hr. In 2023, the constellation expanded to 12 satellites with the launch of three additional satellites, including the introduction of the first CO2 sensing instrument. 

Land operations: We present a comprehensive analysis of the performance across the constellation, demonstrating consistent column precision levels (interquartile range: 1% to 3%) influenced primarily by ground reflectance. To assess the detection threshold, a series of controlled releases were self-organized and performed on a single-blind basis. Fitting our results to a probability-of-detection model we obtain a 50% probability of detection at 3 m/s wind of 102 kg/h. 

Offshore operations: Detecting and quantifying methane emissions from offshore platforms, which constitutes 30% of oil & gas production, is crucial for providing actionable feedback to industrial operators. Utilizing glint mode for offshore measurements, we capture the direct specular reflection of the sun, enabling quantification of atmospheric methane emissions over water. Our findings reveal a median column precision of 2.1%. Through analytical modeling and orbital simulations, we estimate detection limits ranging from 160 kg/h to 600 kg/h, depending on latitude and season.  

CO2 satellite: We provide the status of the recently launched CO2 satellite – with the same swath and spatial resolution as our methane satellites. This unit will bring a new dimension to our knowledge of global greenhouses gases emissions.  

Our presentation underscores the advancements made and insights gained from land and offshore operations, emphasizing the constellation's growing capabilities and the critical role it plays in monitoring and mitigating CH4 and CO2 emissions. 
Material Barriers to the Diffusion of Magnetic Field Lines
Authors: Encinas Bartos Alex Pablo , Kaszás Balint , Servidio Sergio , Haller George
Published: March 2024

Recent work has identified objective (frame-indifferent) material barriers that inhibit the flux of dynamically active vectorial quantities (i.e. linear momentum, angular momentum and vorticity) in Navier-Stokes flows. In the context of magnetohydrodynamics (MHD) the magnetic field vector is directly coupled to the evolution of the velocity field through the Lorentz force and therefore qualifies as a dynamically active vector field. In this work, we identify active Eulerian and Lagrangian barriers that block the diffusion of magnetic field lines in two-dimensional (2D) and three-dimensional (3D) MHD turbulence. These distinguished material surfaces provide physics-based and frame-indifferent active magnetic coherent structures that locally divide the space into two regions with minimal diffusion of magnetic field lines. In 2D, these barriers are directly connected to the electric current density. We propose an algorithm for the automated identification of such barriers from 2D and 3D numerical data of MHD turbulence simulations.
Temporal and spatial dynamics of NOx, SOx and PM emissions from European power plants under different energy transition scenarios
Authors: Draheim Patrick , Buschmann Jan , Pregger Thomas , Jochem Patrick
Published: March 2024

Lowering the use of fossil fuels not only mitigates climate effects by decreasing the emission of greenhouse gases, but also reduces the release of harmful air pollutants into the atmosphere. Thus, the transition to a carbon-free energy system in the upcoming years could potentially have a major impact on lower air pollutant emissions, leading to better air quality and less harmful impacts on human health and ecosystems.Currently, emissions from power plants in the energy supply sector (e.g. coal or oil) contribute strongly to total air pollutant emissions in Europe. Among others, especially emissions of sulphur oxides (SOx), nitrogen oxides (NOx) and particulate matter (PM) are highly relevant regarding air quality issues. In order to be able to make informed statements about the impact of the European energy transition and the phase-out of fossil fuels on air quality, providing detailed information on the temporal and spatial character of air pollutant emissions in the future are required. However, the future projection of air pollutant emissions from power plants poses a major challenge because it is influenced by various factors like the pace of renewable energy rollout, power line capacities and the phase-out of fossil power plants.This work aims to provide estimates of NOx, SOx and PM emissions from power plants in Europe for the year 2030 and to analyse the temporal and spatial dynamics of these emissions in differing energy transition scenarios compared to current emission characteristics.The energy system model framework REMix is used to model activities of power plants in 2030. It considers the effects of power line capacities, renewable energy capacity increase, consumption patterns and the future power plant fleet of European countries in order to simulate power plant activities in high spatial and temporal resolution. The corresponding emission projections are based on current emission factors of power plants, e.g. from emission reports and information on installed flue gas cleaning systems, and are modelled considering the implementation of European emission standards for power plants in 2030.The results show that ambitious scenarios for the energy transition cause significant changes in the spatial and temporal occurrence of the considered air pollutant emissions compared to the current emission characteristics of power plants in Europe.
Paleoenvironment evolution prior to the Carnian Pluvial Episode: Implications for organic matter enrichment in the Qiangtang Basin (Tibetan Plateau)
Authors: Lin Fei , Wang Jian
Published: March 2024

The Carnian Pluvial Episode (CPE; ca. 234–232 million years ago) is an interval with increase in humidity and siliciclastic input, which is linked to global warming, enhanced hydrological cycle, water mass hypoxia caused by the eruption of the Wrangellia Large Igneous Province (Wrangellia LIP). Interestingly, preceding the CPE, there were discernible shifts in paleoenvironmental conditions, manifested through fluctuations in detrital, freshwater, and terrigenous higher plant inputs during that period. This investigation employed various methodologies, including organic geochemistry, elemental geochemistry, and mineralogy analysis of the Bagong and Boli La Formation in the Qiangtang Basin (Tibetan Plateau), to study paleoenvironmental evolution preceding the CPE. The aim was to investigate how these conditions influenced the accumulation of organic matter during this timeframe. Oraganic and elemental geochemical proxies indicated a gradual increase in detrital input prior to the CPE. Combined with decreased paleosalinity indicators, we proposed that enhanced continental inputs prior to the CPE could be associated with an intensified hydrological cycle. Framboidal pyrite morphology and size along with redox sensitive trace element content and ratio indicated anoxic to euxinic bottom water conditions during deposition. Persistently low P/Ti and Ni/Al ratios supported a low biotic productivity, which is adverse for organic matter production. The weak relationship between TOC and redox and productivity proxies indicated that organic matter accumulation was not mainly controlled by reducing condition and low primary productivity. We proposed that three-stage (Intervals A, B, and C) paleoenvironmental evolution before the CPE controlled the accumulation of organic matter in the Bagong Formation. This study provides new insights to paleoenvironmental evolution prior to the CPE, which is of paramount interest for a comprehensive understanding of the CPE.
Orbitally driven bottom-water dynamics during the Maastrichtian 
Authors: Fischer Alexa , Friedrich Oliver , Bahr Andre , Voigt Silke , Batenburg Sietske
Published: March 2024

The long-term global cooling trend during the latest Cretaceous was interrupted by an intense global warming episode at ~69 Ma known as the mid-Maastrichtian event (MME). The MME is characterised by two positive 13C excursions with an overall magnitude of 0.6‰ to 1.5‰, separated by a negative inflection. The 13C excursions are accompanied by the extinction of inoceramid bivalves, an abrupt increase in deep-sea and sea-surface temperatures as well as high terrestrial mean annual temperatures between 21 and 23 °C at a paleolatitude of ~35° N. Changes in oceanic circulation, particularly a change in thermohaline circulation patterns, have been suggested to be one of the main drivers of the MME. In this study, we aim to test this hypothesis by the generation of new high-resolution d13C and d18O analyses, Mg/Ca-derived bottom-water temperatures and CaCO3 wt% records from IODP Site U1403 (J-Anomaly Ridge, North Atlantic). Rhythmic variations in these geochemical records reflect an imprint of Earth´s astronomical parameters. Our results point towards a combination of Large Igneous Province (LIP) volcanism and simultaneous changes in deep-ocean circulation as triggers for the MME. For the North Atlantic, we observe an interplay between warmer and colder bottom-waters in combination with CaCO3 dissolution events. This hints toward a switch in bottom-water source regions between a high- and a low-latitude source region, likely controlled by orbital forcing. With the termination of the MME, bottom-water temperatures started to decrease, and the d13C record indicates an abrupt reorganization of the ocean circulation system towards a solely high-latitude North Atlantic source region for bottom-water.
Computational Fluid Dynamics Model to Simulate Wind Flow Across a Foredune
Authors: Faraji Gargari Saeb , Karssenberg Derek , Ruessink Gerben
Published: March 2024

Coastal dunes serve as important protection against water waves, particularly during storms. Therefore, investigating the formation and migration of dunes is imperative for developing hazard management strategies to protect the mainland. The wind flow over dunes plays an important role in sediment transport around dunes, contributing to their formation and shaping over time. The interaction between dune geometry and wind velocity creates a two-way coupling effect. While experimental and field studies have been conducted to examine the impact of wind velocity and dune geometry, they are often constrained by certain limitations. Numerical methods provide a viable approach to simulate wind/air flow by solving the governing equations (Navier-Stokes equations). Computational fluid dynamics (CFD) methods are commonly employed for such simulations. The objective of this contribution is to study spatial changes in near-bed wind speed and direction across a foredune as a function of the wind approach angle and foredune geometry (height and slope of its seaward side) using OpenFOAM, an open-source code that solves the partial differential equations (PDEs) governing physical problems using the finite volume method (FVM). We first tested the model against data collected at the approximately 15-m high foredune (1:2 slope) at Egmond aan Zee, Netherlands. Consistent with the data, the model shows that the speed-up of the wind from the base to the crest of the foredune depends on the wind approach angle. The speed-up varies almost 3 times to 1 when the wind direction changes from 0 to 90 degrees. The error norm of the CFD results, when compared to the measured data, is less than 10 percent, validating the accuracy of the proposed CFD model. The model was then applied to synthetic foredune profiles, in which we varied foredune height between 6 and 25 m, and slope between 1:4 and 1:2. Our results indicate that speed-up is strongest for highest and steepest dunes. Speed-up is barely notable for dunes 6 m in height and 1:4 in slope. The results also show that the speed-up can grow up to 10 times for a dune with a height of 25 m and 1:2 slope.
Mobile measurements of coal mine ventilation shafts in USCB, Poland.
Authors: Jagoda Paweł , Nęcki Jarosław , Bartyzel Jakub , Swolkień Justyna
Published: March 2024

In order to improve understanding and reduce methane emissions, three comprehensive measurement campaigns were conducted in June and October of 2022, as well as in June 2023. These campaigns were part of the METHANE-To-Go-Poland project, which was funded by the International Methane Emissions Observatory (IMEO) and the United Nations Environment Programme (UNEP). In addition to mobile measurements, other remote sensing techniques such as sun-viewing FTIR and hyperspectral imaging spectrometry, as well as a novel airborne approach called HELiPOD and UAV's, were deployed.Transects were performed using Licor 7810, LGR MGGA918, or Picarro G2301i analyzers along with 2D anemometers and GPS loggers. Recognizing the significant impact of coal mines as a major source of methane emissions, these measurements aimed to enhance our understanding of the dynamics involved in methane release, contributing to ongoing efforts in addressing environmental challenges associated with coal mining.The main focus of the campaigns was a high-emission shaft located in the Silesian Coal Basin, Southern Poland. This site had several favorable characteristics for successful measurements. The investigated ventilation shaft emitted approximately 1.5 tCH4/h of methane (based on the coal mine reporting it excavated 3457 kt of coal, which corresponds to 52.6 kt of emitted methane from the whole coal mine for the year 2021, as calculated for the national methane inventory). The shaft has good prominence, and its surroundings consist mostly of agricultural fields with intersecting roads and only a few barriers like groves and buildings.Numerous transects were also performed at three other ventilation shafts visited during the campaigns. Emission estimates derived using an inverse Gaussian plume model ranged from 0.3±0.1 tCH4/h to 2.5±0.5 tCH4/h for these additional shafts. We attempted measurements at one of the shafts using the OTM-33A technique with the MGGA918 analyzer and a 3D anemometer. These deployments at distances exceeding 200 meters (up to 1450 meters) resulted in emission estimates ranging from 0.6±0.2 tCH4/h to 1.43±0.43 tCH4/h.An overview of the ground-based measurements was analyzed to identify temporal variability in the emission rates from coal mine shafts. This information was also compared with measurements conducted by the coal mine operator using safety sensors (such as CH4-sensitive pellistores placed in the airflow of the ventilation shaft). A secondary goal was to compare the emission rates and measurement constraints for multiple coal mine ventilation shafts.
Climate change impact on the hydrological processes over an alpine basin: the Adige River
Authors: Morlot Martin , Kay Alison L. , Formetta Giuseppe
Published: March 2024

Hydrological extremes (drought and floods) have undeniable financial implications and are predicted to grow in the next years. Yet to understand their future local impacts it is necessary to understand the evolution of the governing hydrological processes. Such is the case for the Adige basin, an important basin in Italy, where understanding changing patterns of hydrological processes is crucial to optimally plan competing water uses, such as hydroelectric production and agricultural water allocation.Euro-CORDEX models provide future climate projections throughout the region, for different emissions scenarios (RCP 2.6, 4.5, 8.5) and climate models (13). Upon the application of a downscaling and bias correction methodology against observed climate variables (i.e. air temperature and precipitation), a process-based semi-distributed digital twin of the Adige River basin is implemented. Hydrological process variables (snow, actual evapotranspiration, soil moisture and discharge) are obtained for the entire basin and the timespans of the different Euro-CORDEX models (1980-2005 for the historical baselines, 2005-2100 for the projections) at daily temporal scale and 5 km2 spatial resolution. The temporal and spatial patterns for discharges are evaluated through the average monthly values for 6 sub-catchments. Other process variables such as snow, actual-evapotranspiration (AET) and soil moisture (SM) are assessed against remote sensing datasets. The resulting climate and hydrological end of the century projections (2075-2100) are compared to historical baselines (1980-2005), to assess projected changes.The digital-twin model is found to reproduce discharge patterns accurately, with an average KGE of 0.8, and provides a good fit for snow and AET, with average correlations of 0.95 and 0.96 respectively. A reasonable fit is found for SM, with an average correlation of 0.5. Careful assessment of the digital twin model through these variables ensures that it reproduces accurately historical local hydrological processes and increases confidence in the quantification of these variables under future projections.The results of our study give regional policymakers insights into possible future scenarios and how these affect water resources and their potential impacts and adaptations on several economic sectors.
Impact of Terrestrial Weather on the MLTI Region as Examined from Satellite Constellations and Model Run
Authors: Khadka Sovit , Gasperini Federico , Oberheide Jens , Mlynczak Martin
Published: March 2024

The mesosphere, lower thermosphere, and ionosphere (MLTI) region of the Earth’s atmosphere connects the Sun and the lower atmosphere, displaying various physical and electrodynamical processes. This transition region exhibits intermittent, daily, seasonal, annual, and solar cycle variability and that can be probed in-situ or remotely to gain insights into the impact of solar as well as terrestrial weather. This study presents the response of the MLTI system to the global-scale waves (GSWs) in terms of the spatial and temporal variations of temperature, plasma, and neutral density from the simultaneous observations by the multi-satellite constellations. Comparisons of these with model results can provide an opportunity to monitor evolutions, variations, and coupling of their GSW structures in the MLTI region. The temperature, plasma, and neutral density variations were diagnosed concurrently from the Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED)‐Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), Defense Meteorological Satellite Program (DMSP), Constellation Observing System for Meteorology, Ionosphere and Climate 2 (COSMIC-2) observations, and Swarm-C satellite constellations, respectively, during 2020-2021 for solar minimum and geomagnetic quiet conditions. Additionally, for the first time, we used an updated version of the Climatological Tidal Model of the Thermosphere (CTMT) to analyze the vertical-temporal-latitudinal tidal structures of temperature and density. The updated CTMT uses solar flux dependent Hough Mode Extensions (HMEs), includes a more extensive collection of TIMED Doppler Interferometer (TIDI) data, compiles SABER V2.08, restructures ion drag and dissipation, and provides tidal components for individual years. We extract the wavenumber (WN) patterns along longitudes in the form of temperature, neutral and electron densities from satellites data, assuming a fixed local time. We then examine tidal components from the new version of CTMT to determine modeling evidence for the variation and coupling of the GSWs under similar conditions. Thereby, we compare the reconstructed WN structures from tidal components obtained from the updated CTMT with the evaluated GSW patterns from the satellite-borne dataset. Using satellite observations and new CTMT approaches, we investigate the impact of terrestrial weather and possible factors that trigger variability, interaction, and coupling processes mediated by GSWs to the MLTI system within ±45o latitudes.
2023 Earthquake Doublet in Türkiye Reveals the Complexities of the East Anatolian Fault Zone: Insights from Aftershock Patterns and Moment Tensor Solutions
Authors: Guvercin Sezim Ezgi
Published: March 2024

On February 6th 2023, Mw7.8 Kahramanmaraş earthquake sequence ruptured a section of ~300 km of the East Anatolian Fault (EAF). The Mw7.8 earthquake was followed by a Mw7.6 event rupturing E-W oriented Çardak Fault on the north of the EAF, ~9 hours later. The ruptured segments characterized by seismic gaps, localized clusters and extensive diffuse zones in the interseismic period. Hence, our understanding of the geometry and kinematics of the western and northern segments remains limited. The February 6, 2023, Mw7.8 Kahramanmaraş on the main branch and Mw7.6 Elbistan earthquakes on the northern branch shed light on the nature of these relatively silent segments. We constructed a comprehensive catalog of ~32,000 earthquakes that occurred between February 6th 2023 and March 30th 2023, using a deep-neural-network-based picker. In addition, 170 earthquake source mechanisms with M3.5+ were obtained from regional moment tensor inversion. The spatial distribution of the aftershocks shows that most of the activity cluster around the fault bends and major depressions. Previously unmapped and inactive secondary faults of varying lengths are identified within these geometrical complexities. Results suggests extension along the Karasu Valley, compression occurring along the Erkenek Segment, reactivation of basin faults near the Narlı Fault Zone and the persistent shallow seismic creep of the Pütürge Segment. The analysis of seismicity and earthquake source mechanisms along the northern branch reveals the structures of previously inactive faults, both near the extensional Göksun Bend in the west and the compressional Nurhak Fault Complex in the east. In this presentation, we present the intricacies of previously quiet segments of the EAFZ and how secondary faults and geometrical discontinuities along the EAF played a role in shaping the 2023 Türkiye Doublet earthquakes.