bluuebunny/crossref_metadata_2025 huggingface dataset:
Adjoint-State Traveltime Tomography of Long Valley Caldera in California
Authors: Chey Chun Fei , Li Tianjue , Tong Ping
Published: February 2023

Long Valley Caldera is a depression located in eastern California, which is the Earth’s largest caldera. Geological structures beneath Long Valley Caldera are mapped by the novel adjoint-state traveltime tomography method. Adjoint-state traveltime tomography is an Eikonal equation-based seismic imaging method. It is computationally efficient as compared to wave equation-based adjoint tomography methods. Furthermore, the method avoids ray tracing in non-homogeneous media, which may fail using conventional ray tracing techniques. The data used in the method include P- and S-wave arrival times gathered from Northern California Earthquake Data Center (NCEDC). P-wave traveltimes are directly obtained from NCEDC, while high-quality S-wave arrivals are carefully picked on raw seismograms based on waveform similarity. With the abundant seismic traveltime data and adjoint-state traveltime tomography method, we can generate high-resolution P- and S-wave velocity models for the region of Long Valley Caldera. The relationship between velocity heterogeneity and seismic and magmatic activities will be investigated.   
Predicting ocean-induced ice-shelf melt rates using deep learning
Authors: Rosier Sebastian , Bull Christopher , Woo Wai , Gudmundsson Hilmar
Published: February 2023

Through their role in buttressing upstream ice flow, Antarctic ice shelves play an important part in regulating future sea level change. Reduction in ice-shelf buttressing caused by increased ocean-induced melt along their undersides is now understood to be one of the key drivers of ice loss from the Antarctic Ice Sheet. However, despite the importance of this forcing mechanism, most ice-sheet simulations currently rely on simple melt-parametrisations of this ocean-driven process since a fully coupled ice-ocean modelling framework is prohibitively computationally expensive. Here, we provide an alternative approach that can capture the greatly improved physical description of this process provided by large-scale ocean-circulation models over currently employed melt-parameterisations, but with trivial computational expense.  This new method brings together deep learning and physical modelling to develop a deep neural network framework, MELTNET, that can emulate ocean model predictions of sub-ice shelf melt rates. We train MELTNET on synthetic geometries, using the NEMO ocean model as a ground-truth in lieu of observations to provide melt rates both for training and to evaluate the performance of the trained network. We show that MELTNET can accurately predict melt rates for a wide range of complex synthetic geometries, with a normalized root mean squared error of 0.11m/yr compared to the ocean model. MELTNET calculates melt rates several orders of magnitude faster than the ocean model and outperforms more traditional parameterisations for 96% of geometries tested. Furthermore, we find MELTNET's melt rate estimates show sensitivity to established physical relationships such as changes in thermal forcing and ice shelf slope. This study demonstrates the potential for a deep learning framework to calculate melt rates with almost no computational expense, that could in the future be used in conjunction with an ice sheet model to provide predictions for large-scale ice sheet models.
Towards exploiting the advantages of a Standard telecom multi-fibre cable for volcano monitoring: an example from Mt. Etna
Authors: Diaz-Meza Sergio , Jousset Philippe , Currenti Gilda , David Air , Clarke Andy , Stork Anna , Chalari Athena , Krawzcyk Charlotte
Published: February 2023

Distributed Dynamic Strain Sensing (DDSS), also known as Distributed Acoustic Sensing (DAS), is becoming a popular tool for volcano monitoring. The sensing method relies on sending coherent light pulses into an optical fibre and measuring the phase-shift of Rayleigh back-scattered light due to strain on the fibre. This provides distributed strain rate measurements at high temporal and spatial sampling rates. Standard telecom fibres have been conventionally used for this purpose, however engineered fibres are being developed to enhance the back-scattered light, providing up to 100 times improved sensitivity in contrast to the conventional standard fibre. Despite the technical advantages of engineered fibres, standard fibres already have extensive coverage around the Earth surface, and so there is an interest in using the existing telecommunication infrastructure. In this study we compare stack DDSS data from a fibre loops made of several fibres within the same optical fibre cable, with DDSS data measured on an engineered fibre. We analyse how stacking can improve the signal quality of the recorded DDSS data. In an area located 2.5 km NE from the craters of Mt. Etna, we spliced 9 standard fibres together from a 1.5 km long cable to create a single optical path and interrogated using an iDAS unit. At the same time, we interrogated with a Carina unit a 0.5 km engineered fibre installed parallel to the standard multi-fibre cable. Both fibres were interrogated in a common period of 5 days. We use a spatial cross-correlation function to find the channel equivalences between each fibre and then stack them to evaluate the changes in the DDSS data and compare with the engineered fibre data. Our results show that, despite engineered fibres have lower noise, a stack of 5 fibres can achieve a maximum noise reduction of 20% outside of the optical noise band, in comparison to the engineered fibre. We achieved this noise reduction for our specific configuration, and so we show how the stack improvement is dependent on the type of configuration in terms of fibres stacked and length of the fibres. Our findings motivate the exploitation of multi-fibre cables in existing infrastructures, so-called dark fibres, for monitoring volcano and applications to other environments.
The NERC Field Spectroscopy Facility UAV Suite
Authors: Ramsay Robbie , Merrington Alex , Gillespie Jack , Hancock Steven
Published: February 2023

The Field Spectroscopy Facility (Edinburgh, UK) is a Natural Environment Research Council public funded body which maintains and provides cutting edge spectroscopy instrumentation and expertise to UK and international researchers. The facility primarily focuses on the provision of ground based spectroscopic instrumentation, often in support of airborne spectroscopic surveys, but was awarded a UKRI capital fund in 2019 for the development of a UAV spectroscopic sensor suite to fill the spatial resolution gap between airborne and ground measurements.Developed as the “NERC Field Spectroscopy Facility UAV Suite”, the new instrument pool consists of various UAV platforms and spectroscopic sensors which can be loaned to UK and international researchers. Instruments include multispectral cameras with sensors matched to Sentinel-2 and WorldView-3 centre wavelengths; thermal cameras covering the SWIR to MIR region; a custom designed UV-VIS spectrometer for measurements of solar induced fluorescence; and the flagship sensor of the suite, a lightweight hyperspectral imager with LIDAR attachment covering the UV-VIS-SWIR region (350 to 2500 nm range).In this presentation, we discuss the development of the FSF UAV suite, discussing our “chain” concept of development – calibration of sensors at our optical laboratory; integration of sensors onto UAVs; logistical planning of flights with associated ground-based data acquisition; and the development of custom processing chains of UAV acquired data. We will highlight select campaigns on which the UAV suite has been used, including macro plastic detection as part of ESA HyperDrone, ecological surveying of large peatlands in Northern Scotland, and support for the ESA-FLEX (solar induced fluorescence sensing) mission. We will also discuss the challenges involved in sensor integration, and provide insight into the novel solutions which we have employed during the development of the UAV suite.  
Harmonization and comparison of soil chemical properties of the LUCAS topsoil database and the Hungarian National Soil Monitoring System
Authors: Benő András , Kocsis Mihály , Szatmári Gábor , Laborczi Annamária , Bakacsi Zsófia , Pásztor László
Published: February 2023

The European Joint Programme Cofound on Agricultural Soil Management has set the goal of harmonizing national soil databases with the continental LUCAS topsoil database for the purpose of monitoring soil carbon, fertility and land degradation. Up-to-date soil surveys have poor spatial resolution and are very cost- and labour intensive, so harmonizing the existing datasets allows us to create more accurate soil maps with better resolution. The LUCAS topsoil database can be used to complement the Hungarian Soil Information and Monitoring System (SIMS) for the creation of more detailed soil-property maps. Due to the different laboratory analysis methods and sampling strategies used by the two databases, conversion was needed, so the datasets can be directly compared to each other and used together for digital soil mapping. Two sets of topsoil data were used from 2009 and 2015 from both LUCAS and SIMS respectively, so the swiftly changing soil properties (pH, CaCO3, OC, P, K) were available for a more accurate side-by-side comparison. Map products were created for the chemical soil properties of both the LUCAS and SIMS database with the ancillary data of 28 environmental covariates using random forest kriging with 10-fold cross-validation. The spatial resolution of the maps was 100 x 100 m. The raster maps were compared directly to each other using linear regression. In conclusion the results show that the LUCAS and national soil databases can and should be harmonized, merged and used together for creating more accurate soil maps with better spatial resolution at national and continental scale.
Morphology-dependent degradation and fragmentation of PVC microplastic particles influence their transport in saturated quartz sand columns
Authors: Tumwet Faith , Serbe Rebecca , Scheytt Traugott
Published: February 2023

Since microplastics are an obstinate pollutant in terrestrial environments, posing a risk to the subsurface soil matrix and entering inland waters via erosion pathways, it is necessary to understand their transport behaviours. The morphological descriptors used to characterize microplastic particles are usually highly subjective. This study explores the transport and retention behaviour of 125 – 200 μm Polyvinyl chloride (PVC) plastic fragments in saturated quartz sand (1.6 – 2.0 mm) columns. Retention profiles at different ultrapure water flow rates (2.0 – 3.5 ml/min) were compared and analysed. At the beginning and end of each column test, the microplastic particles were scrutinized, identified, and quantified by light microscopy. Each particle was characterized by dimensionless 3D morphological descriptors that can describe any particle shape. The results showed that the transport distance of microplastic particles increased with decreasing diameter of the microplastic particles. PVC microplastic particles, whose morphology was more 1-dimensional, were more susceptible to degradation and fragmentation within the column, promoting migration. Microplastic degradation into fragments appeared to play an important role in improving the movement of particles. This study offers initial indications of infiltration depths and morphology-dependent fragmentation of secondary microplastics in coarse sand, outlining the limitations of 2D projected images conventionally used to study the transport of microplastics.
Cost-effective full monitoring system for long-term measurements in lake ecosystems
Authors: Strigaro Daniele , Cannata Massimiliano , Capelli Camilla , Lepori Fabio
Published: February 2023

The concomitance of climate changes and human activities effects is a mix of co-factors that can induce unknown dynamics and feedbacks which need to be studied and monitored. Lakes are one of the most affected natural resources. Due to their importance for economy, water supply, tourism it is essential to safeguard their health. Unfortunately, lake monitoring is dominated by very high costs of materials and by proprietary solutions that are a barrier for data interoperability. To this end, an integrated system which uses as much open source licensed technology as possible and is open source itself will be presented. The main idea is to create a complete pipeline that can integrate different data sources by means of processes that can make the time series organized and accessible and then be served via standard services. Data integration allows further analysis of the data to produce new time series either by manual or automatic processes. This proposition also includes the creation of an Automatic High-Frequency Monitoring (AHFM) system built using cost-effective principles and meeting open design requirements. The preliminary results and the applications of this solution will be described such as the calculation of the primary production and the quasi real-time detection of algal blooms. The study area where this system has been developed and tested is Lake Lugano in the southern part of Switzerland, which is a very productive lake affected by climate changes effects. The developed system permits the integration of the historical data measured with the traditional campaigns on the lake with new datasets collected with innovative technologies so that the comparison and validation of datasets can be more easily performed. In this way it is possible to detect biases and create automatic data pipelines to calculate indicators and notify alerts. 
Vulnerability of key urban infrastructures to geo-hydrological hazards: how endangered is the city of Bujumbura?
Authors: Nsabimana Jean , Henry Sabine , Ndayisenga Aloys , Kervyn François , Dewitte Olivier , Michellier Caroline
Published: February 2023

In urban areas, networks and life-support systems, such as roads, power lines and drinking water pipes, are key infrastructures which contribute to the functioning of the city. Their damaging or destruction can lead to harmful consequences for the population. Such situation has already occurred in several African cities following the impact of a hazard of natural or human-induced origin. Bujumbura, the economic capital of Burundi, is no exception to such scenario, particularly as a result of geo-hydrological hazards which regularly affect various neighborhoods of the city: floods, flash-floods, river bank collapse, large urban gullies. For instance, the February 2014 flash flood damaged several key infrastructures in the north of Bujumbura, including the National Road number 1, a medium-voltage line and drinking water pipes.The goal of this study is to show how, in an urban system like the city of Bujumbura, the vulnerability of these key infrastructures to geo-hydrological hazards can lead to the fragility of a large territory. This vulnerability is influenced by weaknesses related to their wear or age, their construction technique, and their dependence on external systems for their effective functioning. In addition to their own weaknesses, these key infrastructures are exposed to several natural hazards that can lead to their damage or destruction. In Bujumbura, the geo-hydrological hazards that regularly impact the city are accentuated by the lack or outdated rainwater drainage facilities and the inadequacy of the urban development plan.After listing, locating and characterizing all the infrastructures that play a role in the life of the population in the urban environment, a classification, based on a participatory approach, was developed to select those on which the vulnerability assessment focused. Six forms of vulnerability (intrinsic, dependency, hazard exposure, control capacity, alternative operation, and crisis management) were assessed for each key infrastructure. To assess each form of vulnerability, interviews were conducted with facility managers (28) to supplement the data from the literature and field collection. Geometric weighting was performed to highlight the most vulnerable infrastructure that could disrupt the functioning of others and, by extension, that of the city.The results of this study show that several road sections in the center and at the exit points of Bujumbura, as well as the drinking water treatment plant and the pumping stations, stand out among the most vulnerable infrastructures. Continued efforts are required to maintain, protect, and strengthen these networks and life-support systems in the face of geo-hydrological hazards, as their damage or destruction due to cascading effects caused by dependence on, or wear and tear of, infrastructure can affect a much wider area than just the hazard impact zone.
Morphology and evolution of foreshock structures in a high-Mach number hybrid-Vlasov simulation of Earth's magnetosphere
Authors: Battarbee Markus , Archer Martin , Hietala Heli , Plaschke Ferdinand , Palmroth Minna , Turc Lucile ,   the Vlasiator team
Published: February 2023

Counter-streaming particles reflected from the Earth's bow shock towards the Sun build up the ion foreshock, exciting right-handed ultra-low frequency (ULF) waves, which convect with the solar wind back to the bow shock. As these waves move Earthward, they steepen and interact with each other, forming a complex wave field consisting of various foreshock structures. Observations of foreshock structures have classified them as, for example, ULF waves, shocklets, short large-amplitude magnetic structures (SLAMS), cavitons, and spontaneous hot flow anomalies (SHFAs). We present results from a high Mach number 2D-3V hybrid-Vlasov Vlasiator simulation of the Earth's bow shock and foreshock during quasi-radial IMF and place them in the context of spacecraft observations. We combine spatial analysis of bulk characteristics within the foreshock with virtual spacecraft observations to evaluate the morphology of foreshock structures as they form, and how they subsequently evolve as they approach the Earth's bow shock.
Orientation-dependent recrystallization and extreme ductility in a sheared quartz vein
Authors: Kilian Rüdiger , Stipp Michael
Published: February 2023

Microstructures in quartz are widely used to draw inferences on conditions and history of deformation. In particular quartz recrystallization microstructures are often assumed to provide an interdependent information on e.g., deformation temperatures, strain rates or grain boundary mobility. Piezometric approaches attempt to relate a given recrystallized grain size or low angle boundary (LAB) structure to differential stress during deformation.Here, a decimeter-scale, sheared quartz vein from the Central Pyrenees hosted in phyllites of the Hospitalet Massif was studied by means of EBSD. The sheared part of the vein consists of a mm-scale, planar, parallel layering representing an estimated shear strain > 5. The layering is defined by domains of different crystal orientations and a pronounced contrast in recrystallization behavior. Domains with the c-axis about normal to the kinematic section consist of almost single grains which stretch to aspect ratios > 40, show a very homogeneous LAB pattern, little dynamic recrystallization (< 20 vol%) and recrystallized grain sizes have a volume weighted mode of ~8 µm. Based on boundary misorientations and microstructure, recrystallization is inferred to proceed predominantly by a combination of subgrain rotation, and geometric recrystallization. The second type of domains consists of non-recrystallized remnants of old grains with low aspect ratios, a very heterogeneous LAB structure and c-axes within the kinematic plane, for example normal to the foliation. Recrystallization at overall > 50 vol% proceeds in localized, often conjugated bands. Bands and c-axes of recrystallized grains within those bands are inclined in mutually opposite directions, unrelated to the host crystal orientation. The grain size varies systematically for different band types, e.g. bands in a C' orientation contain the largest recrystallized grain size (~12 µm). Recrystallization is inferred to proceed, at least partially, by nucleation and local grain boundary migration. The third type of domain shows mixed behavior, whereat more highly sheared parts correlate with a smaller recrystallized grain size and c-axis directions changing towards the normal of the kinematic section.Neither the dependence of grain size on recrystallization processes, nor the orientation-dependent recrystallized grain sizes and LAB structure are easily compatible with a single controlling factor, i.e. flow stress. The data suggest that especially the orientation of host grains plays a non-negligible role in controlling recrystallization mechanisms, LAB structure and dynamically recrystallized grain sizes. This relationship needs to be considered when investigating highly deformed rocks which usually exhibit a strong degreee of preferred orientation.
Towards automated seasonal river discharge ensemble forecasts on a federated compute and data infrastructure
Authors: Sperna Weiland Frederiek , Buitink Joost , Langemeijer Jaap , Oonk Raymond , Backeberg Bjorn
Published: February 2023

The wealth of available global datasets at high spatial and temporal resolutions opens many opportunities for hydrological modelling and forecasting. It is now possible to provide high-resolution hydrological simulations for a river basin anywhere in the world, even in basins without in situ observations. Combined with the strength of global parameter estimations of the wflow_sbm concept (Imhoff et al, 2021), this allows us to build and run hydrological models without calibration. These models can ultimately be used to provide discharge forecasts for the seasonal time scale. Here we present a workflow that tests the interoperability, scalability, and performance of combining cloud and high-throughput compute and data resources. The workflow combines open source technologies, including containerization, to provide automated monthly river discharge forecasts for practically every basin on the globe on cloud, HTC and in the future HPC platforms. We leverage the global ERA5 and SEAS5 products from the Copernicus Climate Data store as input for the wflow hydrological model. The workflow automatically downloads the required input data for the model domain, resamples the data to the required model grids, and runs the simulations. The workflow is automatically triggered every month when new SEA5 forecasts become available. Prior to running the forecasts, the ERA5 files are used to update the hindcast model states in preparation for the forecast. Next, 50 wflow ensemble members, forced using the SEAS5 forecasts, are run in parallel to provide estimates on the probability of discharge events. The workflow is currently set up and running for the Rhine basin on SURF’s high-throughput computing platform, but can easily be deployed on different infrastructures and for different river basins. 
Environmental parameters as a critical factor in understanding mosquito population
Authors: Angelou Anastasia , Gewehr Sandra , Mourelatos Spiros , Kioutsioukis Ioannis
Published: February 2023

The transmission of West Nile Virus is known to be affected by multiple factors related to the behavior and interactions between reservoir (birds), vector (Culex-mosquitos), and hosts (humans). Environmental parameters can play a critical role in understanding WNV epidemiology. The aim of this research was to determine the association of various climatic factors with the Culex mosquito abundance in Greece during the period 2011-2022. Climate data were acquired from ERA5 (European Centre for Medium-Range Weather Forecasts), while Culex abundance data were obtained through the mosquito surveillance network of ECODEVELOPMENT S.A, who hold the biggest mosquito surveillance network in Greece. The research was conducted at the municipality level. Culex abundance depends in a nonlinear fashion from temperature (Figure 1). The spread of the measurements indicates however there are other factors that affect the abundance of mosquitoes.Figure 1 Scatter plot of air temperature VS Culex abundance in a municipality (Delta) with relatively sizeable mosquito population.Correlation heatmaps were used as a tool to visualize the correlation of vector abundance and average monthly temperature up to 2 months before at several municipalities in the Region of Central Macedonia. The correlations decrease with increasing the lag in temperature (Figure 2). Moreover, there are some municipalities in which the correlation coefficient is considerably greater than others. Those correlations cannot be explained without considering the mosquito breeding sites found in these municipalities. In these municipalities there is a presence of important water resources, such as rice paddies, drainage canals, wetland systems or a combination of all the above. When surface waters warm and the outside temperature rises, the mosquito life cycle is completed more quickly, resulting in more generations being produced in a shorter period of time.Figure 2 Correlation heatmap of the correlation coefficient between the mosquito abundance (municipality scale) and the average monthly temperature up to 2 months before.Scatterplots and correlation heatmaps calculated with the Culex abundance and total precipitation, relative humidity or wind speed did not reveal similar patterns. Ongoing analysis focuses in more factors, environmental and not, which affect the abundance of mosquitoes that transmit WNV.Acknowledgments This research has been co‐financed by the European Regional Development Fund of the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code: Τ2ΕΔΚ-02070). 
Decision-Making on Nature-Based Solutions for Multifunctional Coastal Climate Adaptation
Authors: Geukes Haye , Van Oudenhoven Alexander , Van Bodegom Peter
Published: February 2023

Nature-based solutions (NbS) are fast becoming the norm for multifunctional climate adaptation to the combined challenges of increased sea-level rise, coastal population densities, and erosion of sandy shores worldwide, delivering functions such as flood prevention, recreation, and biodiversity benefits. However, it remains a challenge to the research field to inform decision-makers well on the outcomes and trade-offs of designing, planning, and managing the multifunctional NbS. This study set out to identify the information requirements by decision-makers on NbS for coastal climate adaptation. Using the Sand Motor in The Netherlands as a case study, we applied a policy science framework to distinguish four stages of decision-making to quantitatively analyse the content of functions and indicators utilized per stage in public policy documents. These stages are the ambition, political, bureaucratic, and provisioning processes. This study is the first comprehensive empirical investigation distinguishing these crucial stages of decision-making to analyse NbS information requirements. Our results show, most notably, that as the project developed through the decision-making stages, the content of the functions and indicators changed from abstract to concrete. And, with it, the content of the information required shifted significantly. These results suggest that it is crucial for academic researchers to recognize the decision-making process their information will be used in and adapt its content and level of abstraction accordingly to increase its uptake in decision-making. This study lays the groundwork for future research into the multiple dimensions of NbS decision-making and for the increased understanding of the information requirements on evaluation and trade-offs in planning, designing, and managing NbS, to increase the ability of NbS to deliver multifunctional coastal climate adaptation for sandy shores worldwide.
Recovery Pathways from Extreme Flood Events: Lessons and Experiences of Flooding in Lagos, Nigeria
Authors: Okunola Olasunkanmi , Werners Saskia
Published: February 2023

The recent increase in the frequency of flood episodes in cities of sub-Saharan Africa reveals the extent to which these cities are ill-equipped and prepared to reduce, adapt, learn and transform from future risks. One of such cities is Lagos, the foremost manufacturing and port city in West Africa. In recent years, the city has experienced frequent unprecedented flood events with devastating direct and indirect impacts on health, social, economic, and financial systems, notably for the vulnerable. Previous efforts by the state government to manage flood impacts have been towards distributing relief materials and relocating flood victims to temporary shelters. The repercussions of frequent extreme flood events necessitate the city to refocus efforts on climate-resilient recovery and not just response. Climate-resilient recovery entails taking a step back, and systemically reviewing all hazards and impacts to be expected, drivers of vulnerability and how to recover in an inclusive, equitable and resilient manner. This study therefore aim to understand the recovery process after previous flood events to build resilient equitable futures in this low-lying city. A multi-methods approach, which includes in-depth interviews, grey materials, and policy document analysis, was adopted to assess the impacts of flood risks, recovery experiences, as well as conceptualize and identify recovery indicators and governance strategies in the study area. Of particular interest is the exploration of the extent to which the current existing institutions and policy frameworks have been a barrier or enabler for climate-resilient recovery and what we can learn from this about how institutions and policy frameworks can build resilience after extreme events. We argue that institutions and the associated policy frameworks and political will play an essential role in building holistic and comprehensive climate-resilient recovery to extreme weather events. These themes have been explored within the broader scope of the Sendai Framework for Disaster Risk Reduction 2015 - 2030.
The Effects of a Stably Stratified Region on the Formation of Zonal Winds on Gas Planets
Authors: Wulff Paula , Christensen Ulrich , Dietrich Wieland , Wicht Johannes
Published: February 2023

The outer regions of both Gas Giants in our Solar System, Jupiter and Saturn, feature strong, alternately Eastward and Westward moving zonal winds. Cloud tracking has yielded latitudinal profiles of these winds, which are longitudinally invariant and steady in time to a high degree and reach all the way to the polar regions. However, reproducing these features in numerical simulations has proved difficult as certain physical transitions at various depths are required to both enable winds to form and be maintained at the higher latitudes, and then be quenched at the depths inferred from gravity measurements.A sub-adiabatic region in combination with an increase in electrical conductivity seems to be key, but makes the dynamics rather complex. In this study we analyse how the two transitions affect the zonal winds formed in an overlying convecting region, as well as how they then penetrate into the respective stably stratified and dynamo regions.Particularly in the case of Jupiter evidence is accumulating for a stably stratified layer, shallower than where Helium rain may be expected, based on interior models and magnetic field modelling. However, the nature of such a shallower layer and its exact depth is still very undetermined. This study helps to constrain the depth at which this stratified region begins relative to the depth of the transition into the dynamo region. We find that when the transition to high electrical conductivity is much deeper than the transition into the stable region, zonal winds form at all latitudes. When the boundary of the dynamo region becomes shallower, high-latitude jets are diminished in amplitude and cease to reach the polar regions.
Timing and duration of Termination IV using stable isotope records of four stalagmites from Dechencave (western Germany)
Authors: Riechelmann Dana Felicitas Christine , Schöne Bernd Reinhard , Scholz Denis
Published: February 2023

Four stalagmites were sampled from different excavations in Dechencave (western Germany) and dated to Marine Isotope Stage (MIS) 9. MIS 9 is a very interesting interglacial due to its comparatively high concentration of greenhouse gasses (Lang & Wolff, 2011) and high temperatures (Petit et al., 1999), which are on the same level as during early industrial times (Robertson et al., 2001). Speleothem records from this time period are rare, in particular from central Europe. The stalagmites were precisely dated by the 230Th/U-method using MC-ICP-MS (Mainz University) and stable carbon and oxygen isotope composition were measured using CF-IRMS (Mainz University).The stalagmites grew from 343 to 326 ka BP including Termination IV and MIS 9e. The stable oxygen isotope records of the four stalagmites show rapidly increasing values reflecting the temperature increase during the termination. The timing of this increase agrees well with the timing of Termination IV in the LR04 benthic foraminifera stack (Lisiecki & Raymo, 2005). However, the duration of the termination is shorter in the stalagmites than in the LR04 benthic foraminifera stack (Lisiecki & Raymo, 2005). The stable carbon isotope data decrease, but later and more gradually than the stable oxygen isotope data. This indicates a delayed and more gradual response of the evolving vegetation in response to the warming during Termination IV.  Lang, N., Wolff, E.W., 2011. Interglacial and glacial variability from the last 800 ka in marine, ice and terrestrial archives. Climate of the Past 7, 361-380.Lisiecki, L.E., Raymo, M.E., 2005. A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records. Paleoceanography 20.Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.M., Basile, I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pépin, L., Ritz, C., Saltzman, E., Stievenard, M., 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, 429.Robertson, A., Overpeck, J., Rind, D., Mosley-Thompson, E., Zielinski, G., Lean, J., Koch, D., Penner, J., Tegen, I., Healy, R., 2001. Hypothesized climate forcing time series for the last 500 years. Journal of Geophysical Research: Atmospheres 106, 14783-14803.
High spatial and temporal resolution precipitation over Mediterranean basin for Digital Twin Earth Hydrology and 4dMED projects
Authors: Filippucci Paolo , Mosaffa Hamidreza , Brocca Luca , Massari Christian
Published: February 2023

The Mediterranean basin is a complex environment characterized by both exceptional biodiversity and intense human presence. This environment is already highly influenced by the anthropogenic activities, but their importance is expected to rise up due to the forecasted increase of population (from 480 million people to 520-570 million by 2030) and ongoing climate change. These conditions will trigger an increase of human pressures, including urbanization, industrialization, the expansion of intensive agriculture activities (i.e., irrigation) and aquaculture, thus threatening the natural resources availability, and specifically the water availability. Droughts, floods and landslides events are already stepping up in this environment, making it urgent to develop models systems capable to predict the extreme complex and widespread climate variations of this area.ESA recognized the crucial role of this region by funding the Digital Twin Earth (DTE) Hydrology Evolution and the 4dMED projects, specifically dedicated to reconstruct the Mediterranean terrestrial water cycle at 1km spatial and 1 day temporal resolution and to develop a prototype of Digital Twin for the entire Mediterranean basin, which can be used for the prediction of hydrological extremes, the management of the water resource cycle and the simulation of the changes that the system may undergo. To reach those objectives, the latest developments of Earth Observation (EO) data as those derived from the ESA-Copernicus missions will be exploited together with in situ observations, hydrological and hydraulic models, artificial intelligence tools and advanced digital platform functionalities.Among the hydrologic variables datasets generated within these projects, precipitation holds a major role due to its influence on the natural hazards occurrence. Here, we show the procedure adopted to generate the high spatial and temporal resolution precipitation product over the Mediterranean region by downscaling and merging different satellite and in-situ precipitation products. The obtained dataset is evaluated against high resolution observed data in several region of the Mediterranean basin, in order to assess its performance with respect to others EO derived precipitation datasets.
An observational record of global near surface air temperature change over land and ocean from 1781 to present
Authors: Morice Colin , Berry David , Cornes Richard , Cowtan Kevin , Cropper Thomas , Kennedy John , Kent Elizabeth , Rayner Nick , Osborn Timothy , Taylor Michael , Wallis Emily , Winn Jonathan
Published: February 2023

We present a new data set of air temperature change across land and ocean extending back to the late-18th century. This new data set uses marine air temperature observations rather than the sea surface temperature measurements typically used by pre-existing data sets. This allows the new data set to extend further into the past than existing instrumental temperature records, which typically have start dates in the mid-to-late 19th century. The new data set brings together advances in understanding of measurement biases affecting all-day marine air temperature observations with a new assessment of the effects of non-standard thermometer enclosures used at land meteorological stations in the early instrumental record. A further innovation is the use of kriging to obtain localised temperature estimates that allow land air temperature records to be converted into anomalies even for stations without observations during the baseline period. Global and hemispheric series show close agreement with those based on sea-surface temperature for much of the overlapping period of their records, some of the interesting differences will be presented. This data set has been developed under the GloSAT project (https://www.glosat.org/).
Constraining phytoplankton response to climate change in the Southern Ocean using observed mixed layer depth seasonality
Authors: Xue Tianfei , Frenger Ivy , Terhaar Jens , Koeve Wolfgang , L. Frölicher Thomas , Prowe A.E. Friederike , Oschlies Andreas
Published: February 2023

Phytoplankton, as the base of the marine food web, has great importance for marine ecosystems and the global carbon cycle. However, Earth system models indicate considerable uncertainty of our knowledge about the underlying processes that determine phytoplankton evolution under climate change. Particularly large differences between models can be found in the Southern Ocean, a region notorious for its difficulty in modeling. The objective of this study is to analyze the potential phytoplankton response to climate change from both a "bottom-up" and a "top-down" perspective. Within the Southern Ocean, we determine a relationship between surface phytoplankton and mixed layer depth under present-day seasonality and apply it to climate change on a longer timescale. Applying this present-day constraint, we confirm the trend of increasing surface phytoplankton by the end of the 21st century under a 'high emissions no mitigation scenario' with further reduction in phytoplankton projection uncertainty. The increase of surface phytoplankton is due to weakening bottom-up control as a result of improving light conditions with shoaling mixed layers. At the same time, due to shoaling mixed layers, total phytoplankton biomass integrated over the water column slightly decreases. Zooplankton follows the trend of surface phytoplankton and shows an increase. This is mainly caused by improved zooplankton grazing conditions with shoaling mixed layers that result in enhanced efficiency of trophic energy transfer. In comparison with the changes in bottom-up conditions, top-down control appears to become increasingly important under climate change in the Southern Ocean.   
Constraining groundwater recharge estimates at the field scale using soil hydrologic modelling and measured root zone soil moisture: how to deal with the vertical sensitivity of cosmic-ray measurements
Authors: Scheiffele Lena M. , Munz Matthias , Francke Till , Baroni Gabriele , Oswald Sascha E.
Published: February 2023

Root-zone soil moisture is decisive in partitioning the water fluxes at the land surface, e.g. between evapotranspiration and groundwater recharge. Field-scale estimates of these time variant recharge rates can be derived from 1D soil hydrologic models, if the soil moisture product represents the respective scales and dynamics, and lateral fluxes can be neglected. Measured soil moisture time series can be used to calibrate these models by optimizing soil hydrologic properties (SHPs) and in this way increase confidence in simulated downward flux from a soil column (potential groundwater recharge). To obtain indirectly and non-invasively measure soil moisture at the field scale, Cosmic-ray neutron sensing (CRNS) has gained increasing attention in the last years. However, the variable penetration depth of the sensor and its decreasing sensitivity with depth and distance from the sensor complicate the interpretation of the soil moisture product and limit direct comparison to simulated soil moisture.Within this study a two-layered Hydrus-1D model (up to 1.5 m depth) has been set up at an agricultural field site for one cropping season and calibrated using different soil moisture products to derive potential groundwater recharge estimates. While the use of point soil moisture sensor network data (SN) in the optimization is straightforward, different options to use CRNS data are evaluated: i) the COSMIC operator (simulates neutron count rates) ii) weighting simulated soil moisture according to CRNS vertical sensitivity, iii) applying a soil moisture profile correction on measured CRNS soil moisture before comparison.Optimizing the SHPs did result in very good model performance for the SN as well as for the CRNS options (KGE > 0.86). While the SN delivers information down to a depth of 90 cm, using CRNS data that considers the vertical sensitivity (option i) and ii)) can result in difficulties informing the bottom layer of the model, which shows in optimized SHPs hitting the previously determined parameter bounds. Compared to that, using CRNS option (iii) leads to slightly reduced performance measures in the optimization but better informs the SHPs of the bottom layer when averaging modeled soil moisture over a fixed depth. For the successful optimizations, regardless of the method, recharge rates vary little and are comparable to independently estimated water flux at the field site.Results of the study confirm the ability of the profile correction to increase CRNS information content to the main rooting zone and the validity of assuming a fixed integration depth, although this is expected to vary between field sites. This encourages also the use of CRNS soil moisture for non-experts of the method for soil hydrologic and landscape models as well as water balance calculations targeting downward fluxes.
Recent trends in vegetation phenology across the southern Mediterranean region, and potential climatic drivers
Authors: Mirgol Behnam , Dieppois Bastien , Northey Jessica , Eden Jonathan , Jarlan Lionel , Tramblay Yves , Mahé Gil , El Hazdour Ikram , Khabba Saïd , Hanich Lahoucine , Le Page Michel
Published: February 2023

The agriculture sector is sensitive to changes in weather and climate, notably extreme events. Extreme variations in weather conditions throughout a growing season led to changes in phenological features of vegetation and crops and cause variations in harvest, and, generally, the impact could be large in terms of production amounts and then food security in the region. The last version of the Intergovernmental Panel on Climate Change report (IPCC) highlighted the southern Mediterranean region as a hot spot and one of the most vulnerable regions in the world. While numerous studies have addressed changes in climate extremes throughout the world, very little research has been conducted in the southern Mediterranean region concerning the seasonal concurrence of climate extremes, and their evolutions in recent decades.  Moreover, understanding the impacts of these changes on vegetation phenology is crucial in the region, but this is yet to be studied.This study evaluates the impact of climate extremes on vegetation phenology in the southern Mediterranean region over the last 40 years. Firstly, the trends of 15 phenological vegetation indicators (e.g., length of the growing season, maximum Normalized Difference Vegetation Index [NDVI] value/time, onset/offset times, green upslope, brown downslope, etc.) are examined using National Oceanic and Atmospheric Administration [NOAA] satellite images and the modified Mann-Kendall trend test. Secondly, we examine how recent trends in vegetation phenology compare with those observed in various heat-related indices (heat wave characteristics), water-related indices (Standard Precipitation Index [SPI], Standard Precipitation Evapotranspiration Index [SPEI], Extreme Precipitation, Wet/Dry spells), and compound indices (Dry-Cold, Dry-Hot, Wet-Cold, Wet-Hot events) calculated using the ERA5-land dataset. Finally, we examine the relative importance of each climate indicator in explaining multi-year changes in vegetation phenology. As such, this study not only identifies the areas with higher risk and vulnerability for vegetation and crops in the last years but also identifies potential predictors for seamless seasonal-to-decadal forecasts of agrometeorological risks across the region.
Global measurements of cloud properties using commercial aircraft
Authors: Lloyd Gary , Gallagher Martin
Published: February 2023

In-Service Aircraft for a Global Observing System (IAGOS) is a European research infrastructure that uses the infrastructure of commercial aviation to make in-situ measurements of the atmosphere. We present data from the cloud sensing instrument installed on these aircraft between 2011 and 2021. This includes 1000s of flights across the globe that detect the concentration of cloud particles over the range 5-75 um and this provides information about seasonal variation in cloud frequency across different parts of the globe. From these measurements we are able to estimate properties such as Liquid/Ice Water Content (LWC/IWC), The Effective Diameter (ED) and Mean Volume Diameter (MVD).