bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost-effectiveness uncertainty may bias the decision of coal power transition in China
Authors: Yan Xizhe , Tong Dan
Published: March 2024

Coal power transition always maintains a high complexity as the heterogeneities of characteristics such as technical attribute, economic lock-in, and environmental and health impact. Here, we explored the cost-effectiveness uncertainty brought by policy implementation disturbance of different phaseout and new-built strategies (i.e., the disruption of phaseout priority) of coal power based on a developed unit-level uncertainty assessment framework, and revealed the opportunity and risk of coal transition decision by employing preference analysis. We found that, the uncertainty of policy implementation might lead to potential delays in yielding the initial positive annual net benefits. For example, a delay of 6 years might occur when the prior phaseout practice is implemented. A certain level of risk remains in the implementation of the phaseout policy, as not all strategies can guarantee the achievement of positive cumulative net benefits from 2018-2060. Since the unit-level heterogeneities shape diverse orientation of decision making, the decision-making preferences would significantly alter the selection of coal transition strategy. While the uncertainty of policy implementation might lead to missed opportunities in identifying optimal strategy. Our results highlight the importance of minimizing the policy implementation disturbance, which helps mitigate the risk of negative benefits and strengthen the practicality of phaseout decision.
How unusual was Australia's 2017-2019 Tinderbox Drought?
Authors: Falster Georgina , Coats Sloan
Published: March 2024

Australia’s Murray-Darling Basin experienced three consecutive years of meteorological drought across 2017–2019, collectively named the ‘Tinderbox Drought’. Rainfall deficits during the three-year drought were focussed in the Australian cool season (April to September), and deficits in both the cool season and the annual total were unprecedented in the instrumental record. However, at ~120 years long, Australian rainfall records are not long enough to have captured the full possible range of variability, particularly for multi-year extreme events. That is, observations are an incomplete sampling of the full possible range of rainfall variability. Climate model simulations may provide longer timeseries, however climate models have known biases in Australian rainfall (Grose et al. 2020). Therefore, to determine if the Tinderbox Drought was outside the expected range of internal variability, we constructed Linear Inverse Models (LIMs) that simulate internal variability in Australian rainfall and associated global sea surface temperature (SST) anomalies. We used the LIMs to produce 10000-year-long rainfall records that emulate the stationary statistics of observed Australian rainfall, hence reflecting more of the full possible range of variability. Overall, we find that rainfall deficits were most severe 1) in the northern Murray-Darling Basin; and 2) during the final year of the drought (2019). Global SST anomalies during the drought mostly did not resemble the pattern that is most reliably associated with low rainfall over the Murray-Darling Basin (warm anomalies in the central tropical Pacific and the western Indian Ocean). In fact, global SST anomalies observed during the Tinderbox Drought are not reliably associated with negative rainfall anomalies across the Murray-Darling Basin—this is particularly the case for the first two years of the drought. In terms of single-year rainfall anomalies, the only aspect of the Tinderbox Drought that was beyond the expected natural range was annual-total rainfall over the northern Murray-Darling Basin during 2019. However, when considered in terms of basin-wide rainfall over the full three years, negative anomalies during the Tinderbox Drought were beyond the expected natural range in terms of both cool season and annual rainfall. This suggests an anthropogenic contribution to the severity of the drought. Additionally, we find that Linear Inverse Models are a valuable tool for estimating whether or not an observed extreme rainfall event falls within the expected natural range.ReferencesGrose, M. R., Narsey, S., Delage, F. P., Dowdy, A. J., Bador, M., Boschat, G., et al. (2020). Insights from CMIP6 for Australia's future climate. Earth's Future, 8, e2019EF001469.
 Improving the sustainability of arable cropping systems by modifying root traits: a modelling study for winter wheat
Authors: Coucheney Elsa , Kätterer Thomas , Meurer Katharina , Jarvis Nick
Published: March 2024

Crop breeding to increase below-ground production and inputs of organic matter into soil has been attracting increasing attention as a potentially effective strategy to enhance soil organic matter (SOM) stocks and thus the quality of soil and sustainability of arable cropping systems. We used the new soil-crop model USSF (Uppsala model of Soil Structure and Function) to investigate the potential for increasing SOM whilst maintaining or improving yields by modifying the root system of winter wheat in terms of below-ground allocation of carbon and key root traits. USSF combines physics-based descriptions of soil water flow, water uptake and transpiration by plants, with a simple (generic) crop growth model and a model of soil structure dynamics and soil organic matter turnover that considers the effects of soil physical protection and microbial priming. The USSF model was first calibrated against field data on soil water contents and both above-ground and root biomass of winter wheat measured during one growing season in a clay soil in Uppsala, Sweden. Based on five acceptable calibrated parameter sets, we created four model crops (ideotypes) by modifying root-related parameters to mimic winter wheat phenotypes with improved root traits. Long-term (30-year) simulations of a conventionally tilled monoculture of winter wheat were then performed to evaluate the potential effects of cultivating these ideotypes on soil water balance, soil organic matter stocks and grain yields.Our results suggest that exploiting winter wheat varieties that allocate more assimilate to the root system would not in itself have any positive effect on soil organic matter storage and would also decrease grain yields. In contrast, deeper root systems or root systems that are more effective for water uptake were predicted to slightly increase grain yields, as well as increasing SOM stocks in the soil profile by ca. 3 to 5%. Combining all three improved root traits showed even more promising results: compared with the baseline “business-as-usual” scenario, SOM stocks in the soil profile were predicted to increase by ca. 7% in a 30-year perspective (as an average of the five parameter sets) without negatively impacting yields.
Multiple melt extraction in Neo-Tethyan mantle and the Supercontinent heritage: insights from geochemical signatures of mantle peridotites from Naga Hills ophiolite, Indo-Myanmar ranges
Authors: Verencar Anisha , Saha Abhishek , Ganguly Sohini , Satyanarayanan Manavalan , Ram Mohan Mekala
Published: March 2024

The Naga Hills Ophiolite (NHO) exposed on the northeastern margin of India, represents a thrusted section of Neo-Tethyan oceanic lithosphere comprising distinct crustal and upper mantle lithologies accreted onto continental margins at Indo-Myanmar ranges during late Cretaceous-Eocene collision between Indian and Eurasian Plates. This study focuses on the whole-rock geochemistry and Re-Os isotopic compositions of the mantle peridotites from NHO to address the implications on the upper mantle heterogeneity and thermo-tectonic evolution of Neo-Tethyan oceanic lithosphere through time. The chondrite normalized REE patterns, and low Re/Os, suggests that, these are mantle residues resulting from ~5–20% of melt extraction from a spinel peridotite source. The refractory characters of the studied mantle peridotites from NHO are further complemented by relatively enriched concentrations of transition elements like Cr, Ni and Co with respect to primitive mantle composition. PGE modeling from melt fractionation indices [(Pt/Ir)N and (Pd/Ir)N] and depletion index (Al2O3) corroborates discernible melt depletion trends. Isotopically, these mantle peridotites are subchondritic with 187Os/188Os (0.1218-0.1266) and γOs (gamma osmium) values of -3.73 to -0.09 comparable with depleted MORB mantle source.  LILE-LREE enrichment, HFSE depletion, and U-shaped chondrite-normalized REE patterns, distinct S-undersaturated trend and Re addition suggest multistage petrogenetic processes including refertilization of pre-existing depleted, refractory mantle wedge by subduction-derived fluids and instantaneous fractional melts operative in an intraoceanic fore-arc environment. Re-Os isotopic plots reflect the role of ancient depleted Subcontinental lithospheric mantle (SCLM) and the large variations in ɣOs values attest to involvement of both SCLM and depleted MORB component thereby contributing to pronounced Os isotopic heterogeneities in the upper mantle that in turn manifest inputs of discrete depleted and enriched mantle components during opening and closure of ocean basins synchronized with assembly and dispersal of continental blocks. The model ages (TMA) for the mantle peridotites reveals a wide spectrum of ages  ranging from 1142 Ma – 145 Ma suggesting multiple episodes of melt extraction events prior to the opening of Neo-Tethys (~250Ma) and encapsulation of ancient SCLM fragments correlatable with Gondwana Supercontinent amalgamation and disintegration coupled with closure and opening of the Tethyan ocean basins.
Phase state and chemical composition of PM2.5 in Northeast Asian cities: Insights for aerosol pollution
Authors: Song Mijung , Seong Changjoon , Kim Daeun , Wu Zhijun , Kim Changhyuk , Jang Kyoung-Soon , Lee Jiyi , Lee Kwangyul , Ahn Joonyoung , Natsagdorj Amgalan
Published: March 2024

The phase state and chemical composition of PM2.5 are pivotal factors that influence their pollution mechanisms. Nevertheless, there is a notable gap in our understanding of how chemical composition affects the phase state of PM2.5. To address this gap, we conducted an investigation into the influence of chemical composition on the phase state of PM2.5 in four prominent cities: Seoul, Seosan, Beijing, and Ulaanbaatar, spanning from 2020 to 2023. Our research has unveiled that the range in which PM2.5 can exist in liquid, semisolid, and solid states may exhibit variations contingent upon its chemical composition. By emphasizing the significance of aerosol chemical characteristics on the phase state, this study significantly contributes to our comprehension of how phase state and chemical composition underpin atmospheric pollution mechanisms. The results will be presented.
Distinct changes in boreal summer intraseasonal oscillation over the western North Pacific under mega and equatorial La Niña conditions
Authors: Cao Can , Wu Zhiwei
Published: March 2024

Recent studies suggest that La Niña events can be classified into two categories: mega La Niña and equatorial La Niña. The understanding of the variations in boreal summer intraseasonal oscillation (BSISO) behaviors between such two conditions remains uncertain. Results in this work show during equatorial La Niña summers, in conjunction with the more adequate intraseasonal column-integrated moisture anomalies, the weaker intraseasonal outgoing longwave radiation anomalies are observed over the western North Pacific (WNP) at 3 pentads lag of the peak phase for the Maritime Continent (MC) BSISO events than during mega conditions. Such changes are closely linked with the different propagation features, specifically northwestward and northeastward propagations under mega and equatorial conditions respectively. The distinct propagations under these two conditions could be partly explained by the background column-integrated moisture anomalies. Under equatorial conditions, the less sufficient background moisture anomalies over the tropical western Pacific (WP), in comparison to mega conditions, suppress the activities of the BSISO and its northwestward propagation here. Meanwhile, the enhanced moisture anomalies over the northwestern MC and its surrounding area (NWMC) facilitate the northeastward propagation. Under mega conditions, the background moisture anomalies over the tropical WP are not significant. The southward moisture anomaly gradient over the NWMC hinders the meridional northward propagation and makes some BSISO activities move to the tropical WP region, performing the zonal westward propagation as a whole. The moisture budget and multi-scale interaction diagnoses also emphasize the significant role of the propagation change in the moisture tendency difference averaged over the WNP. Moreover, the extratropical circulation anomalies associated with the MC BSISO events are also discussed. These findings provide new insights into BSISO activity and offer potential improvements for subseasonal forecast.
Eco-Geomorphological mapping of the Camposoto Barrier System in Cadiz Bay, S Spain
Authors: Delgado-Fernandez Irene , Martín-Gallego Pilar , Montes Cristina , Benavente Javier , del Río Laura , Plomaritis Theocharis A. , Costas Susana , Gracia Javier , Barbero Luis , Fernández-Montblanc Tomás , Marston Christopher
Published: March 2024

Barrier systems are complex environments made up of various coastal sub-units that often include (from sea to land) the shoreface and beach, coastal dunes, and marshes. Barriers are shaped by diverse forces with sub-units reflecting the degree of wind and wave energy they are exposed to, sediment composition, and tidal regime among other aspects.
This study delves into the eco-geomorphological complexities of the Camposoto barrier system in the Cadiz Bay area, S Spain. Employing satellite remote sensing, UAV multispectral sensors, and fieldwork, different eco-geomorphological units have emerged that challenge conventional delineations between sub-units and relative location to the shore. The Camposoto barrier system shows a general retreating trend, with erosion rates between 1 and 2 m yr-1, mostly linked to storm events and a lack of sediment supply. The system is intersected by multiple washover fans and is characterised by large differences in sediment sizes and composition, a bi-modal wind regime, and complex dune topography. Marsh vegetation can be found atop dunes, while coarse beach sediments infiltrate deep into the barrier. This gives rise to a mosaic of barrier environments and a complex interplay between barrier sub-units. This study's preliminary outcomes show the capabilities of remote sensing tools for coastal mapping and for refining our understanding of barrier environments and evolution.
Forest management affecting the impact of natural disturbances on the mitigation potential of European forests
Authors: Chiriacò Maria Vincenza , Buonocore Luca , Valentini Riccardo
Published: March 2024

Natural disturbances are increasingly exerting pressure on European forests, compromising the forest ecosystems dynamics and significantly impacting their functioning, as well as the provision of ecosystem services, including the potential for climate change mitigation. The disturbance regimes are even expected to be exacerbated by climate change in the near future. Nevertheless, there is growing evidence indicating that forest management practices can play a pivotal role in influencing the impacts of natural disturbances on forests. Currently, in most European countries, forest harvest is below the increment, resulting in a projected increase in growing stock - that is however reaching saturation. This means that a higher amount of carbon is retained in the forest growing stock, making it more susceptible to disturbances and tree mortality that reduce the carbon residence time in living biomass and soils thus compromising the carbon storage potential of forests.
According to a recently published database, during the past decades (1990-2019) more than 2.3 billion m3 of living biomass were lost in European forests due to different causes of disturbance: wind, fire, spruce bark beetle, other biotic agents (i.e., fungi, nematodes, other insects, pathogens, and animals damaging trees) and other abiotic disturbance (i.e., drought, snow, ice, hail, and rime). 
In this study we assessed the potential amount of carbon that would have been saved from the forest disturbances losses in the period 1990-2019, considering the application of a different historical forest management involving higher wood harvesting intensity across Europe. We derived data and information from different existing databases and literature sources to define for each European country the unutilized woody biomass as a portion of the net annual increment that could potentially have been harvested but was instead lost due to natural disturbances, as recorded in the EFI database.
Results show that with a hypothetical full utilization of the net increment in European forests, up to 75 MtCO2 emissions could have been avoided during the period from 1990 to 2019 (i.e. about 2.5 MtCO2 every year, on average) and instead stored in Harvested Wood Products, serving as a long-term carbon stock, or utilized as substitute for energy-intensive materials or fossil fuel.
Modelling the effectiveness of multiple natural flood management interventions at a large catchment scale
Authors: Zhu Qiuyu , Klaar Megan , Willis Thomas , Holden Joseph
Published: March 2024

While natural flood management (NFM) as a resilience flood mitigation strategy is widely used in the UK and Europe, there remains a lack of scientific evidence regarding its effectiveness. The primary uncertainties stem from two aspects: the determination of NFM effectiveness on flood mitigation is limited by the scale of impact assessment; and the combination of multiple NFM interventions implemented within a catchment which may result in flood synchronicity. We argue that the effectiveness of combined scenarios involving multiple NFM interventions within a catchment can vary.  We utilize a hydrological model that simulates both instream and terrestrial interventions at a large catchment scale. To demonstrate how scale and interventions interact to determine flood peaks, we integrated various NFM interventions and land cover changes within the upstream catchment into a model, including afforestation, soil aeration, catchment/floodplain restoration and hedge planting. We modelled existing and planned scenarios using a spatially distributed hydrological model, Spatially Distributed TOPMODEL (SD-TOPMODEL). In comparison to previous versions of TOPMODEL, we have improved the simulation efficiency to allow for the simulation of up to a 200-year return period flood event at a larger catchment scale (~84 km2); and simplified the model parameters which are not related to the effects of NFM interventions and retained three key parameters which are physically significant. Following extensive parameter calibration and validation, the model is stable, providing a reliable fit for flood peaks, with the Nash-Sutcliffe coefficient (NS) between modelled and observed discharge reaching up to 0.905. The modelling results illustrated the effectiveness of NFM interventions in reducing flood peaks at a large catchment scale. Further refinements will involve incorporating additional types of NFM interventions into our next coupled model. 
Opportunities and challenges of Ensemble Forecast and Cross-Validation for MOEA optimisation in water resources management
Authors: Spinelli Davide , Giuliani Matteo , Castelletti Andrea
Published: March 2024

The acceleration in the hydrological cycle and increased frequency and intensity of extreme events prompt a shift towards adaptive control strategies in water reservoir management. In this study, we explore the potential of improved hydro-meteorological forecast products, particularly those extending to longer time scales and incorporating uncertainty information through Ensemble Forecast (EF), to facilitate this transition.In particular, we consider the problem of managing Lake Como, a regulated system with diverse objectives, including flood prevention, low-level avoidance, and meeting downstream agricultural and hydroelectric generation demands. The lake operation can be informed using short-term, locally calibrated deterministic forecasts as well as sub-seasonal/seasonal large-scale ensemble forecasts from the European Flood Awareness System (EFAS), a part of the Copernicus Emergency Management Service.The lake regulation is determined by operating policies derived using the Evolutionary Multi-Objective Direct Policy Search method, resulting in Pareto optimal policies capable of integrating various forecasts as inputs. This approach is seamlessly integrated with our newly developed algorithm, PECAN (Parallel Ensemble foreCAst coNtrol), designed to harness uncertainty information within EF. Validation of these policies is crucial for determining their generalisation capabilities, and it is performed through Blocked K-Fold Cross-Validation.In this study, we demonstrate the presence of overfitting during the optimisation process and present an early stopping rule designed to save computation time while learning robust policies. Additionally, we introduce a second rule to dynamically determine epsilon parameters for the ε-approximate Pareto front, particularly useful in the presence of diverse multi-year climatic conditions. Through the application of these rules, we show the importance of cross-validation, highlight the greater generalisation capabilities of PECAN, and present how PECAN enables EF at longer time ranges to be competitive against locally calibrated deterministic forecasts at shorter intervals.
Presenting lidar surface returns as Aeolus product with the outlook on future spaceborne lidar missions including EarthCARE and Aeolus-2 
Authors: Labzovskii Lev D. , van Zadelhoff Gerd-Jan , Donovan David P. , de Kloe Jos , Tilstra L. Gijsbert , Stoffelen Ad , Stammes Piet , Josset Damien
Published: March 2024

We previously discovered the sensitivity of Aeolus lidar surface returns (LSR) to surface characteristics and reported very good agreement of LSR with Lambertian Equivalent Reflectances from passive remote sensing instruments for the first year of Aeolus on orbit. In this way, we provided the first evidence that active remote sensing can be used for retrieving unidirectional UV surface reflectivity. Here, as a continuation of this effort, we report the detailed methodological solutions for retrieving and evaluating LSR to be implemented as official L2A product during Phase-F of Aeolus project for its entire lifetime. Unlike our previous report that relied on detecting surface bin using our own methodology and assumptions, we now align the approach of detecting surface bins with the official Aeolus processing methodology for retrieving LSR and elaborate on the resultant differences. Besides that, we report how this successful application of atmospheric spaceborne lidar data for inferring land surface reflectivity properties can be translated for future lidar missions such as EarthCARE and Aeolus-2. On one hand, our results will briefly introduce all the details of the LSR retrieval for Aeolus with its unique and complex optical setup (highly-non nadir incidence and UV wavelength) for broad audience for the first time. On the other hand, we will shed light on the opportunities and challenges of LSR-alike retrievals for future lidar spaceborne missions, thereby trying to minimize the key methodological uncertainties associated with implementation of LSR algorithms.
Simulation Study of Whistler-Mode Chorus Wave Generation in the Earth's Inner Magnetosphere
Authors: Wang Xueyi , Omura Yoshiharu , Chen Huayue , Hsieh Yikai , Lin Yu , Chen Lunjin
Published: March 2024

Whistler-mode chorus waves play an important role to control electron dynamics in the Earth’s radiation belt. Most of the existing theoretical and simulation studies on the chorus waves assume a one-dimensional field-aligned wave propagation. Physics of the chorus wave excitation and evolution in the multi-dimensional dipole field geometry still remains a challenge. The oblique propagation will be subject to wave attenuation at higher latitudes and introduce additional harmonic resonances. We have conducted simulations of two-dimensional chorus waves excited by hot anisotropic electrons interacting with cold dense plasma in a dipole magnetic field. It is found that the rising tone element of chorus waves with frequency chirping from low frequency to up to higher than the half electron gyro-frequency is generated at low latitudes. As the chorus wave propagates toward high latitudes, the wave becomes oblique and both the Landau and cyclotron resonance become significant. Two bands chorus waves are thus formed. In addition, we have found that a strong wave-particle interaction process presents in multi-dimensional electron distribution during the formation of chorus wave subpackets. The nonlinear physics associated with the wave growth and wave frequency chirping has been quantitatively evaluated in the process of chorus wave development.
Simultaneous precipitation of U4+ and U6+ in quartz-pebble conglomerate in the Singhbhum Craton, India.
Authors: Mallick Smruti Prakash , Mondal Amit , Lochan Pruseth Kamal
Published: March 2024

Uranium is generally mobilized in solutions in U6+-complexes and gets precipitated as compounds containing the U4+ ion. Here we report hydrothermal remobilization of U, and the simultaneous precipitation of U6+ and U4+ in the Paleoproterozoic quartz-pebble conglomerate (QPC) from the Mankarchua basin, Singhbhum Craton, India. Uranium occurs associated with vein pyrite in the basal QPC of the Mankarchua basin, suggesting a clear hydrothermal origin of the mineralization. The pyrites occur linearly in veins and are replaced U-bearing minerals. Detrital monazites are the source of U. Newly formed fine-grained U-free monazites are observed along with crandallite series minerals (Ca,Ba,Sr,Pb)Al3(PO3.5(OH)0.5)(OH)6., suggesting alteration of detrital monazite by moderately oxidising acidic fluids. The remobilized U precipitates when it encounters pyrite and apatite. Brannerite (UTi2O6, containing U4+) forms concomitantly with the oxidation of pyrite, while autunite (Ca(UO₂)₂(PO₄)₂·10–12H₂O, containing U6+) forms by replacement of apatite. Thus, detrital or hydrothermal apatite enriched zones with or without pyrite may serve as U-traps for potential mineralization.
Assessment of the risk and extent of seawater intrusion using geophysical techniques and vulnerability models: case of the coastal aquifer of Souss-Massa, Morocco
Authors: Ez-Zaouy Yassine , Bouchaou Lhoussaine , Hssaisoune Mohammed , Saad Aicha , Ait Brahim Yassine
Published: March 2024

Groundwater resources represent one of the main pillars of socio-economic development in the Souss-Massa region, an important producer of fruits and vegetables in Morocco. However, the quality of groundwater resources is degraded due to drought, lack of aquifer recharge, and over-pumping which increase the risk of seawater intrusion. The latter threatens the coastal aquifer of Souss-Massa. Hence, a detailed study is needed to explore the extent of seawater intrusion and to identify its most vulnerable sites. To fulfill this objective, geophysical investigations (SMD-TEM) and an improved GALDIT index were used. In addition, groundwater quality index (GQI) and vulnerability maps were combined to generate a risk map of seawater intrusion. The results show that seawater intrusion reaches 2500 meters from the coast, and its depth is around -35 meters above sea level. Moreover, improved GALDIT divided the study area in five classes, showing high and very high degrees in the coastal fringe and along the two rivers of Souss and Massa. Furthermore, our risk map indicates three level of risks, with the highest levels recorded in the south-west of the coast, namely in Tifnit, Douira, and Sidi R’bat. A typical management strategy plan was proposed to ensure the protection and sustainability of groundwater resources for current and future uses. The proposed methodology could be applied in similar contexts and can be adapted to the specific hydrogeological conditions.
Changing Juno's orbital period and its effect on gravity science at Jupiter
Authors: Parisi Marzia , Buccino Dustin R. , Oudrhiri Kamal
Published: March 2024

NASA’s Juno spacecraft successfully completed its prime mission in 2021 by performing 33 close encounters with Jupiter, and it is presently in its extended phase. These encounters, known as perijoves, occurred every 53 days at altitudes of about 4,000 kilometers above the planet's 1-bar surface and were specifically designed to study Jupiter's magnetosphere, atmosphere, and gravity field. During the nominal mission, Juno’s gravity science experiment achieved an unparalleled level of accuracy in resolving the planet’s low- and high-degree zonal gravity field. By employing precise Doppler-tracking techniques via X- and Ka-band radio links, scientists were able to estimate Jupiter’s gravity moments and rotational parameters, offering insights into its internal structure and deep atmospheric dynamics.Prior to the initial science perijove in 2016, there were plans to reduce the Juno orbital period from 53 days to 14 days, marking the beginning of science operations. However, a potential anomaly in the propulsion system led to the decision to keep Juno in its 53-day orbit, lengthening the duration of the prime mission by roughly a factor of four. This had far-reaching implications, impacting both science operations and mission management. Nevertheless, the Juno team adeptly adapted to these unforeseen circumstances by promptly laying out a new mission plan. The change in the orbital period also held significant consequences from a scientific point of view: for instance, the ability to carry out Jupiter's radio occultations during the extended mission is directly related to this event. Here we explore in detail the repercussions from a radio science operations and gravity science point of view and discuss the impact of orbital period changes on reaching the experiment’s prime mission objectives.© 2024 California Institute of Technology. Government sponsorship acknowledged.
Three-dimensional Lagrangian microplastic transport simulations in the Gulf of Naples (Southern Tyrrhenian Sea)
Authors: Gifuni Luigi , de Ruggiero Paola , Cianelli Daniela , Pierini Stefano , Zambianchi Enrico
Published: March 2024

The high-resolution Campania Regional Ocean Model (CROM), coupled with an online Lagrangian particle tracking algorithm, is used to investigate the horizontal and vertical behavior of different (in terms of size and density) plastic polymer types during February and August 2016 in the Gulf of Naples. The transport of passive particles is evaluated based on the three-dimensional Eulerian velocity fields provided by the ocean model. The virtual particles are released in several hot spot areas in the Gulf of Naples where most of the marine debris is supposed to come from. A sensitivity analysis on the vertical sinking for negatively buoyant particles is carried out. The sinking behavior is determined by the settling velocity, which depends on the physical properties of the individual litter item as well as on the hydrodynamical features of the marine environment. Different numerical experiments are carried out to evaluate the effect of marine dynamics on three-dimensional transport.
Seismicity on Venus: optimal detection methods and target regions
Authors: van Zelst Iris , De Toffoli Barbara , Garcia Raphaël F. , Ghail Richard , Gülcher Anna J. P. , Horleston Anna , Kawamura Taichi , Klaasen Sara , Lefevre Maxence , Lognonné Philippe , Maia Julia , Näsholm Sven Peter , Panning Mark , Plesa Ana-Catalina , Sabbeth Leah , Smolinski Krystyna , Solberg Celine , Stähler Simon
Published: March 2024

With the selection of multiple missions to Venus by NASA and ESA that are planned to launch in the coming decade, we will greatly improve our understanding of Venus. However, none of these missions have determining the seismicity of the planet as one of their primary objectives. Nevertheless, constraints on the seismicity remain crucial to understand the tectonic activity and geodynamic regime of the planet and its interior structure. Funded by the International Space Science Institute (ISSI) in Bern, Switzerland, we have gathered an interdisciplinary team of experts in seismology, geology, and geodynamics to assess the potential seismicity of Venus, specific regions that could be seismically active at present, and the methods to detect them.Here, we present the findings from our second ISSI team meeting (January 29 - February 2, 2024), aiming to review knowledge on Venus's seismicity and interior and identify the best approaches for future missions. We present the feasibility, advantages, and disadvantages of different seismic observation techniques on the surface (e.g., broadband seismometers, distributed acoustic sensing methods), from a balloon (acoustic sensors), and from orbit (airglow imagers). We make a recommendation for the instrumentation of a future seismology-focused mission to Venus. We also suggest target regions with a high likelihood of significant surface deformation and/or seismicity. These targets are useful for the upcoming VERITAS (Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy) and EnVision missions and would specifically benefit from the repeat pass interferometry of VERITAS, which detects surface deformation and can therefore in principle constrain the maximum displacement of surface faulting at locations that are visited twice during the mission. 
Prediction of the Interannual Rainfall Variability in the Sahel: Insights from Atmospheric Circulation Patterns 
Authors: Rauch Manuel , Bliefernicht Jan , Kunstmann Harald
Published: March 2024

The Sahel region is characterized by significant rainfall variability and has experienced hydrological changes, including a major drought from 1968 to the 1990s, followed by a subsequent period of rainfall recovery since the 1990s. Addressing this variability, this study introduces a statistical approach for predicting interannual rainfall anomalies within the region. Initially, k-means is used to classify daily atmospheric circulation patterns over West Africa, based on key variables like the V-component of wind at 700 hPa and wind speed at 200 hPa. The two high-altitude wind fields are crucial for understanding the monsoon dynamics due to their direct linkage with African Easterly Waves and the Tropical Easterly Jet. Subsequently, the annual occurrence frequencies of the atmospheric circulation patterns, along with the annual rainfall conditions in the Sahel region, are used as inputs for a multi-class logistic regression model. This model is designed to predict dry, normal, or wet years relative to the climatology. Moreover, the research presents the spatial composites of the atmospheric circulation patterns, along with a detailed explanation of the logistic regression model, an analysis of seasonal pattern occurrences, and their meteorological interpretations. The model has shown success in predicting annual rainfall variability, achieving an average proportion correct of 0.77. This level of accuracy establishes the model as a reliable tool for predicting annual rainfall amounts in the Sahel zone, offering significant insights into the climate of the region. 
Use of Cosmic-ray Neutron Sensing for soil water management
Authors: Köhli Markus , Weimar Jannis , Ney Patrizia , Nieberding Felix , Stowell Patrick , Torre Netto André , Goergen Klaus , Bogena Heye , Schmidt Ulrich
Published: March 2024

Accurate soil moisture (SM) monitoring is key in climate modeling, hydrological observations and irrigation as it can greatly improve water use efficiency, the understanding of energy transfer over the land surface and ground water dynamics. Recently, Cosmic-Ray Neutron Sensors (CRNS) have been recognized as a promising tool in SM monitoring due to their large footprint of several hectares and half a meter in depth. Using this technique one can relate the flux density of albedo neutrons generated in cosmic-ray induced air showers to the amount of water in the environment. CRNS have great potential as to the non-invasive nature of the method and the low-maintenance independently operating sensors. In the last years this type of sensor has been integrated into several national and international monitoring networks like COSMOS, COSMOS-UK, ADAPTER and TERENO sites. Initially, CRNS instruments have relied on the use of a scarce material - helium-3. In order to scale up the method and to reduce costs within the CosmicSense research group recently large-scale instruments have been developed using alternative technologies including readout electronics and data acquisition systems. With a more economical operation the initial focus on hydrological research Cosmic-Ray Neutron Sensors are emerging into applied agricultural contexts, for example irrigation management and soil moisture mapping. Examples are the integration of CRNS into the SWAMP (LoRa) or the Nb-IoT network of the German Chamber of Agriculture. This project, called ADAPTER, involves the development and provision of innovative simulation-based information products for weather- and climate-resilient agriculture. These are daily (”soil”) weather and comprehensive long-term climate change information available to the agricultural community and all interested parties as easy-to-use analyses, data products with forecasts, and information interfaces. Still, challenges for CRNS are posed for scenarios especially for irrigated fields with a size smaller than the CRNS footprint or heterogeneous conditions with respect to the biomass distribution.
Mapping Africa’s geothermal potential: new surface heat flow and crustal temperature models from integrated geophysical-petrological inversion of surface wave and other data
Authors: Clemente-Gómez Carlos , Fullea Javier , Lebedev Sergei , Holdt Megan , Doran Helen
Published: March 2024

Evaluating the geothermal potential of Africa requires a detailed understanding of its crustal and lithospheric structure. A coherent characterization of the geothermal gradient near the surface implies a bottom to top heat flow approach where knowledge of the thermal thickness of the lithosphere, the depth of the crust-mantle boundary, and crustal lithology (thermal conductivity and radiogenic heat production among other things) are essential. Unfortunately, direct measurements of subsurface temperature and local geophysical studies are scarce in most parts of Africa. In this work we present new predicted surface heat flow and crustal subsurface temperature maps, and new crustal structure models in Africa. The new models are obtained from a lithospheric integrated inversion approach using state-of-the-art surface waveform tomography data together with surface heat flow and elevation, crustal p-wave velocity and sedimentary thickness from controlled source seismic data. The inversion is framed within an integrated geophysical-petrological setting where mantle seismic velocities and densities are computed thermodynamically as a function of the in-situ temperature, pressure and compositional conditions. Within the three-layered crystalline crust, we invert for various geophysical parameters linked through lithology using global petrophysical measurements. The results of this work will be integrated into Project InnerSpace’s open-source GeoMap platform (https://projectinnerspace.org/), which aims to accelerate the uptake of geothermal energy by improving our knowledge of the subsurface.
Microplate behaviour of the Andes during co- and early postseismic phases of the seismic cycle
Authors: Figueroa Mara A. , Sobrero Franco S. , Gómez Demián D. , Smalley Jr. Robert , Bevis Michael G. , Caccamise II Dana J. , Kendrick Eric
Published: March 2024

The Central and South-Central Andes form a “two-sided” mountain belt bounded by distinct zones of convergence in the western forearc and eastern foreland flanks. Previous geodetic studies of interseismic deformation in the Bolivian Subandes and the Argentine Precordillera found that the forearc to foreland velocity field decayed too slowly to be explained purely by elastic shortening driven by locking of the Nazca megathrust. The velocity field is more precisely explained if elastic deformation is augmented by eastward displacement of the entire Andes. Here, we extend the earlier interpretation of interseismic motion and argue that foreland décollements can participate in the co- and postseismic phases of the earthquake deformation cycle associated with the Nazca megathrust. These findings have direct implications in estimating recurrence interval, slip rate, and probabilistic seismic hazard analysis on both sides of the orogen.
Improvements in September Arctic sea ice predictions via assimilation of summer CryoSat-2 sea ice thickness observations
Authors: Zhang Yong-Fei , Bushuk Mitch , Winton Michael , Hurlin Bill , Gregory William , Landy Jack , Jia Liwei
Published: March 2024

Because of a spring predictability barrier, the seasonal forecast skill of Arctic summer sea ice is limited by the availability of melt-season sea ice thickness (SIT) observations. The first year-round SIT observations, retrieved from CryoSat-2 from 2011 to 2020, are assimilated into the GFDL ocean–sea ice model. The model's SIT anomaly field is brought into significantly better agreement with the observations, particularly in the Central Arctic. Although the short observational period makes forecast assessment challenging, we find that the addition of May–August SIT assimilation improves September local sea ice concentration (SIC) and extent forecasts similarly to SIC-only assimilation. Although most regional forecasts are improved by SIT assimilation, the Chukchi Sea forecasts are degraded. This degradation is likely due to the introduction of negative correlations between September SIC and earlier SIT introduced by SIT assimilation, contrary to the increased correlations found in other regions.
Assessing the impact of rehabilitation and inter-annual climatic variability on the net ecosystem carbon dynamics of raised bogs in Ireland.
Authors: Saunders Matthew , Ingle Ruchita , McCorry Mark , Barry Stephen , Regan Shane
Published: March 2024

In Ireland, peatland ecosystems cover ~20% of the land area and hold up to 75% of the soil organic carbon stock, however over 90% of these systems have been degraded due to activities such as agriculture, forestry and extraction for horticulture or energy. Due to their climate mitigation potential the rehabilitation of these systems through rewetting forms an integral part of the national climate mitigation strategy in Ireland. A key aspect of this land use policy is the rehabilitation of ~33,000 hectares of former industrially extracted peatlands through rewetting/water table management. The success of these rehabilitation activities are dependent however on maintaining the hydrological integrity of these sites, which are susceptible to inter-annual variation in climate, such as changes in precipitation and temperature.
This study utilised eddy covariance techniques to assess ecosystem to atmosphere dynamics of carbon exchange at two sites, a remnant raised bog ecosystem with five site years of data that was operational during two exceptionally dry climatic years (2018 and 2021), and a former industrial cutaway site where the drains were blocked and the water table raised in  2015. This work provides insight into the vulnerability and resilience of raised bog systems to inter-annual climatic variability and will explore the impacts of the magnitude and duration of reductions in water table height and elevated winter temperatures on both Gross Primary Productivity and Ecosystem respiration. The work also provides further insight into the time dependent impacts and potential emissions savings of peatland rehabilitation as the former cutaway sites undergo both hydrological and ecological transitions.
Bias adjustments for the global historical radiosonde network in preparation for ERA
Authors: Haimberger Leopold , Ambrogi Federico , Voggenberger Ulrich
Published: March 2024

In preparation for the next generation Copernicus reanalysis ERA6, we aim at providing an as complete as possible global insitu upper-air dataset, augmented with additional data and metadata that allow to reduce observation and representation errors in those data. We first reduce representation errors using actual launch times and balloon positions (see presentation by Voggenberger et al.). This allows to get more smaller observation - background (obs-bg) departures compared to the original obs-bg departures calculated during assimilation with ERA5.The obs-bg departures form the basis for comprehensive statistics-based adjustment of biases in temperature, wind direction and also humidity, using the RAOBCORE/RICH method. The corresponding software has been further improved compared to the past year, now including also adjustments for mobile platforms and paying attention to adjustments of the most recent parts of the time series. Results from bias-adjusted temperature records indicate realistic spatial trend heterogeneity and very good fit to reprocessed satellite data products, clearly better than what could be achieved in preparation to the present operational reanalysis ERA5. Temperature Background departures from ERA5 increase substantially, both in terms of mean and standard deviations when going back to the early 1950s and 1940s. It is tried to shed some light whether this increase comes from poorer quality observations or from issues arising due to the less strongly observationally constrained ERA5 state during this period.Wind direction adjustments are necessary only at a few stations but also have a clearly positive effect on trend heterogeneity and obs-bg departures. Humidity bias adjustments are more delicate, since it is not sufficient to shift the distributions by a mean value, rather one has to adjust also the shape of the distributions. Results from humidity bias adjustments, considered experimental, are quite promising up to 300 hPa. Pervasive strong drying trends over large countries like the US and China could be substantially reduced. More detailed verification is needed, however.
A Regime View of ENSO Flavors Through Clustering in CMIP6 Models
Authors: Vaittinada Ayar Pradeebane , Battisti David , Li Camille , King Martin , Vrac Mathieu , Tjiputra Jerry
Published: March 2024

El Niño-Southern Oscillation (ENSO) flavors in the tropical Pacific are studied from a regime perspective. Five recurring spatial patterns or regimes characterizing the diversity of ENSO are established using a clustering approach applied to the HadISST sea surface temperature (SST) anomalies. Compared to previous studies, our approach gives a monthly characterization of the diversity of the warm and cold phases of ENSO established from observations but commonly applied to models and observations. Two warm (eastern and central El Niño), two cold (basin wide and central La Niña) and a neutral reference regimes are found. Simulated SST anomalies by the models from the latest Coupled Model Intercomparison Project Phase 6 are then matched to these reference regimes. This allows for a consistent assessment of the skill of the models in reproducing the reference regimes over the historical period and the change in these regimes under the high-warming Shared Socio-economic Pathway (SSP5.8.5) scenario. Results over the historical period show that models simulate well the reference regimes with some discrepancies. Models simulate more intense and spatially extended ENSO patterns and have issues in capturing the correct regime seasonality, persistence, and transition between regimes. Some models also have difficulty simulating the frequency of regimes, the eastern El Niño regime in particular. In the future, both El Niño and central La Niña regimes are expected to be more frequent accompanied with a less frequent neutral regime. The central Pacific El Niño and La Niña regimes are projected to increase in amplitude and variability. Reference:Vaittinada Ayar, P., Battisti, D. S., Li, C., King, M., Vrac, M., & Tjiputra, J. (2023). A regime view of ENSO flavors through clustering in CMIP6 models. Earth's Future, 11, e2022EF003460. https://doi.org/10.1029/2022EF0034