bluuebunny/crossref_metadata_2025 huggingface dataset:
In-situ Measurements of the Emissivity of Ice and Snow surfaces in the Mid- and Far-infrared
Authors: Warwick Laura , Murray Jonathan , Panditharatne Sanjeevani , Brindley Helen , Schuettemeyer Dirk , Oetjen Hilke
Published: March 2024

Knowledge of the emissivity of the Earth’s surface is vital for understanding the Earth’s radiation budget. However, there is a lack of emissivity measurements in the far-infrared (wavenumbers less than 667 cm-1 or wavelengths greater than 15 μm) despite studies showing that the surface emissivity in these regions can have a discernible impact on the outgoing longwave radiation. In-situ measurements of surface emissivity in the far-infrared are also needed to support the upcoming far-infrared satellite missions; the Polar Radiant Energy in the Far-InfraRed Experiment (PREFIRE) developed by NASA and due to launch in spring 2024, and the European Space Agency’s Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM) mission due to launch in 2027.To fill this observational gap, the Far INfrarEd Spectrometer for Surface Emissivity (FINESSE) was developed at Imperial College London. FINESSE has a spectral range of 400 to 1600 cm-1 (6.25 to 25μm) and is designed for in-situ measurements of surface emissivity, particularly in cold climates.In this presentation we present observations from the first deployment of FINESSE to the ALOMAR observatory in Northern Norway (69°16' N, 16° 0' E). We describe the campaign, the radiance measurements made by FINESSE and the auxiliary data taken. We then outline the method used to determine the surface temperature and emissivity and finally present the retrieved emissivity of the ice and snow surfaces.
Implementing a Distributed Processing Framework for Multi-Risk Analysis - A Lessons Learned Perspective
Authors: Brinckmann Nils , Langbein Michael , Proß Benjamin , Vogt Arne , Schöpfer Elisabeth
Published: March 2024

Analysing individual hazards and the associated risk is a challenging task in its own right. It requires a lot of expertise built up over dozens of years. Unfortunately, there are situations where that a single hazard can trigger following - often horrific - consequences. The history of international catastrophes is full of examples: The fires in San Francisco after the 1906 earthquake due to destroyed gas pipelines; the tsunami that destroyed the Fukushima nuclear power plant after the Tohoku earthquake, or the climatic effects of the Krakatau eruption in 1883.In our RIESGOS project we have been working on an demonstrator app to analyse multi-risk-scenarios - with a strong focus on the earthquake-tsunami combination. This is an use case that is very relevant in our partner countries Ecuador, Peru and Chile - and the knowledge is provided here by the partner institutions of the RIESGOS consortium.The technical approach is strongly focused to be standard based using OGC Web Processing Services, as well as to be distributed. This allows to use the specific expertise of each of the partner institution to be taken into account, to share the involved data & algorithms that have been built up and refined over years.What we focus in this presentation is a deeper insight into the implementation perspective, with the benefits as well as strategies to overcome challengingaspects that we encounted when working with the distributed risk analysis framework. These include requirements on interoperability, deployments of bundled versions for testing & transfer, monitoring and others.
Towards a data-effective calibration of a fully distributed catchment water quality model
Authors: Rode Michael , Ghaffar Salman , Zhou Xiangqian , Jomaa Seifeddine , Yang Xiaoqiang , Meon Günter
Published: March 2024

Distributed hydrological water quality models are increasingly being used to manage natural resources at the catchment scale but there are no calibration guidelines for selecting the most useful gauging stations. In this study, we investigated the influence of calibration schemes on the spatiotemporal performance of a fully distributed process-based hydrological water quality model (mHM-Nitrate) for discharge and nitrate simulations at Bode catchment in central Germany. We used a single- and two multi-site calibration schemes where the two multi-site schemes varied in number of gauging stations but each subcatchment represented different dominant land uses of the catchment. To extract a set of behavioral parameters for each calibration scheme, we chose a sequential multi-criteria method with 300.000 iterations.For discharge (Q), model performance was similar among the three schemes (NSE varied from 0.88 to 0.92). However, for nitrate concentration, the multi-site schemes performed better than the single site scheme. This improvement may be attributed to that multi-site schemes incorporated a broader range of data, including low Q and NO3- values, thus provided a better representation of within-catchment diversity. Conversely, adding more gauging stations in the multi-site approaches did not lead to further improvements in catchment representation but showed wider 95% uncertainty boundaries. Thus, adding observations that contained similar information on catchment characteristics did not seem to improve model performance and increased uncertainty. These results highlight the importance of strategically selecting gauging stations that reflect the full range of catchment heterogeneity rather than seeking to maximize station number, to optimize parameter calibration.
Impact Chain-based model to assess multi-hazard systemic vulnerability. Case study: Flood and the COVID-19 pandemic in Romania
Authors: Armas Iuliana , Albulescu Andra-Cosmina , Dobre Daniela
Published: March 2024

Vulnerability is the most important predictive variable in the risk equation, but it isn't easy to evaluate the best objective approach to quantify it. Another hot topic of debate among scientists is whether vulnerability analysis describes only patterns or can also produce a quantitative value. The need to streamline and provide comparable and easy-to-use results has led to developing vulnerability indicators. Generally, these provide some form of aggregation of underlying factors, often including hazard exposure. Factor selection varies from deductive approaches, based on theoretical understanding, to inductive ones, based on statistical relationships.For the past thirty years, there have been significant efforts to measure vulnerability, but up to now, the field of vulnerability assessments has been dominated by hierarchical versus inductive approaches.The hierarchical analysis is a transparent approach, more accessible to stakeholders due to its logical structure and statistical support, and capable of functioning with more available datasets for assessing vulnerabilities in the studied areas. These are the most eloquent reasons for preferring the hierarchical approach in stakeholder territorial management and mitigation policies.The inductive, statistical approach developed by Cutter (based on the hazards-of-place model, Cutter, 1996) uses the principal component analysis (PCA) to establish vulnerability factors over time and eliminates the biases from aggregated decisions.Against this background, our study proposes a new model for quantifying vulnerability using an Impact Chain-based approach, taking as an initial case study the powerful flood events and the COVID-19 pandemic that affected Romania in 2020-2021. The hazards, impacts, vulnerability, exposed elements, and adaptation options pertaining to the case study are integrated into a comprehensive Impact Chain that is used as the foundation for the model.The proposed model relies on factorial techniques and ANOVA, with a focus on identifying statistically significant multiple regressions. It also integrates an optimization procedure that enables either a maximum value response or a minimum accepted value.This new framework allows for identifying vulnerability's influencing role in unfolding a multi-hazard and pinpointing the potential ways in which vulnerability can be affected by this unfolding. Thus, the model looks at vulnerability with a double lens, assessing its power to induce change by conditioning impacts and adaptation options and its propensity to change by certain impacts and adaptation options working in asynergy. Only by thoroughly analyzing both of these facets and understanding their implications can we produce bias-(more) free vulnerability assessments, particularly in multi-hazard contexts. Keywords: vulnerability, vulnerability approaches, hierarchical approach, inductive approach, Impact Chain
Sensitivity analysis of root water uptake reduction using the Bartholomeus model in shallow water table scenarios
Authors: Quinonez Vera Laura Raquel , de Jong van Lier Quirijn
Published: March 2024

A frequently used approach to estimate the reduction of the root water uptake (RWU) caused by oxygen stress in hydrological models such as SWAP is the empirical model of Feddes, which describes RWU using a piecewise linear function. Critical values associated with the threshold pressure heads defining oxygen stress (h1 = -10 cm and h2 = -25 cm) seem not to be able to represent properly this condition, because oxygen may start at more negative values of h. As an alternative, Bartholomeus et al. (2008) proposed a model based on physical and physiological soil and root processes to calculate the minimum gas-filled porosity of the soil at which oxygen stress occurs. We performed a sensitivity analysis of the Bartholomeus model focusing on two parameters, the threshold to stop root extension in case of oxygen stress and the air-filled root porosity in shallow water table scenarios cropped with soybean. We performed simulations for five soil types in combination with several water table depths. To do so, the water table was used in SWAP as the lower boundary condition. The sensitivity of the RWU and relative transpiration to combinations of parameters will be shown and discussed. 
The ArtemIS project: Assessment for medium-depth geothermal energy utilization in Germany 
Authors: Weydt Leandra , van der Vaart Jeroen , Sass Ingo
Published: March 2024

To date, the majority of geothermal projects in Germany have focused on deep geothermal systems, while resources at intermediate depths have been little explored. However, intermediate-depth geothermal systems have a high potential for heat generation, even in areas previously considered less favourable for geothermal use, and could make a significant contribution to Germany's heat supply. In order to accelerate the heat transition and to become independent of fossil fuels, the ArtemIS project aims to assess the medium-depth geothermal systems in Germany, covering all types of geological plays and providing regionalised information for different geothermal applications. To this end, profile texts will be developed containing all relevant subsurface information required for preliminary geothermal assessments, such as geological descriptions of potential geothermal reservoirs, reservoir thickness, hydraulic and thermal rock properties, and fluid chemistry. In addition, static 3D geological models are created as the basis for 2D and 3D numerical reservoir models to simulate the regional heat potential and different geothermal exploitation scenarios, including the performance of hydrothermal doublets. Machine learning algorithms will be applied to speed up the extraction and analysis of well data and to improve reservoir evaluation and economic forecasting, particularly in areas of low data density. The results will be integrated into the publicly available web platform "Geothermal Information System - GeotIS", which will provide general information, data and modelling results in a user-friendly way for non-professionals such as local communities and municipal energy suppliers. Here we present the current status and first results of the ArtemIS project.
Healing and strength cycling in a regional scale overthrust: insights from the Sestola Vidiciatico Unit in the Northern Apennines
Authors: Mittempergher Silvia , Remitti Francesca , Tesei Telemaco , Molli Giancarlo
Published: March 2024

During their activity, faults experience multiple seismic cycles, implying that faults recover strength between subsequent failures. Fault strengthening after failure (“fault healing”) occurs through processes having different space and time scales, including fault rock compaction, contact strengthening, contact area increase, fracture self-healing and precipitation of minerals in fractures (sealing). The efficiency of different processes varies depending on the geological setting, fault mechanics and availability and geochemistry of fluids. Here, we present preliminary data from a field-based study of the healing mechanisms of thrust faults inside the Sestola Vidiciatico Unit (SVU) in the Northern Apennines, a tectonic unit interpreted as the plate boundary shear zone between the Ligurian complex and the underthrusting Adria microplate during early-to-middle Miocene, active at temperatures up to 150°C.The thrusts are sharp surfaces lined by calcite shear veins juxtaposing hectometer to kilometer-sized tectonic slices consisting of marls, shales, sandstones and mud-rich mass transport deposits. The marls and shales of the SVU bear a penetrative deformation pattern of fractures and incipient cleavage planes bounding oblate lithons, whose flattening planes define a foliation approximately parallel to the tectonic contacts. In the marls and shales adjacent to the main thrusts decimetric to metric-thick sheared domains may be observed showing an oblique foliation compatible with the sense of transport of the thrusts. Subvertical extensional calcite veins are common in the competent rock lithons. Multiple generations of normal faults lined by calcite shear veins crosscut the thrust faults, the oldest being rotated and deflected within the thrust-related shear zones. Calcite shear veins, in both thrusts and normal faults, display crack and seal domains and implosion breccias.The lack of cataclastic rocks along faults indicates that the thrusts and normal faults were active at low differential stresses and high fluid pressures. Normal faults and subvertical extensional veins mutually crosscutting with thrusts are compatible with episodes of post-failure switching from reverse to normal fault stress regimes. Fault healing is dominated by calcite precipitation, which occurs both during fault slip (in crack and seal veins and implosion breccias), and after failure into subvertical extensional veins. Thrust compaction due to stress rotation is likely to be a factor promoting fault compaction and healing. Furter investigations will be conducted to constrain the origin of fluids involved in the vein cementation and the role of stress rotation in promoting different healing mechanisms.
Observing actual evapotranspiration using smartphone sensors
Authors: Teuling Adriaan J. (Ryan) , Lammers Jasper
Published: March 2024

Evapotranspiration plays a key role in the terrestrial water cycle, climate extremes and vegetation functioning. However, the understanding of spatio-temporal variability of evapotranspiration is limited by a lack of measurement techniques that are low-cost, and that can be applied anywhere at any time. Here we show that evapotranspiration can be estimated accurately using only observations made by smartphone sensors, utilizing standard build-in orientation and light sensors, a handheld weather meter for temperature, pressure, wind and humidity and connected to the phone via bluetooth, and a build-in thermal infrared camera. Individual variables known to effect evapotranspiration generally showed a high correlation with routine observations during a multi-day field test. In combination with a simple ML-algorithm trained on observed evapotranspiration, the smartphone-observations had a mean RMSE of 0.10 and 0.05 mm/h when compared to lysimeter and eddy covariance observations, respectively. This is comparable to an error of 0.08 mm/h when estimating the eddy covariance ET from the lysimeter or vice versa. The results suggests that smartphone-based ET monitoring could provide a realistic and low-cost alternative for real-time estimation of actual ET in the field.
Combining surface spectroscopy and optical microscopy can provide evidence of phase separation induced by photochemical aging of organic aerosol
Authors: Abdelmonem Ahmed , Mahrt Fabian
Published: March 2024

Organic aerosols make up a considerable mass fraction of atmospheric particulate matter, and impact air quality and climate. In the atmosphere, organic aerosols are exposed to different relative humidities (RH), often ranging between 20% to 100% RH. Gas-particle partitioning of water equilibrates the aerosol particles with the ambient RH, forming aqueous organic aerosols. When exposed to solar radiation, photochemical reactions can occur within the aqueous organic aerosol particles. Such photochemical interactions are often enhanced at the interface formed between the aqueous organic phase and the surrounding air. Depending on the changes in composition these photochemical reactions can induce phase transitions of the particles, including liquid-liquid phase separation, resulting in aqueous organic aerosols with multiple condensed phases. Understanding of the interfacial photochemical reaction and impacts on the number of phases in aqueous organic aerosols remains poor but is critical to assess the impacts of aqueous organic aerosols on air pollution and climate. For example, the number of phases in aqueous organic aerosol particles impacts their reactivity and cloud formation potential, with important implications for air quality and climate.Here, we propose how the combination of spectroscopy and microscopy tools can be exploited to address this issue: Sum-frequency generation, a surface-sensitive, nonlinear optical spectroscopy method, is used to investigate bulk laboratory proxies of atmospheric aqueous organic aerosols and study changes in their chemical surface composition, as a function of solar irradiation. In addition, we use optical microscopy, to directly study the number of condensed phases in individual particles of the same aerosol system. The combined methods provide microscopic- and molecular-level insights how photochemical reactions impact the phase behavior of aqueous organic aerosols.
Biological soil crusts regulate evaporation dynamics and energy partitioning over terrestrial surfaces
Authors: Kim Minsu , Aminzadeh Milad , Bickel Samuel , Shokri Nima , Weber Bettina
Published: March 2024

Biological soil crusts (hereafter, biocrusts) occurring in drylands modify near-surface soil properties which influences land-atmosphere interactions and exchanges of energy and matter. Yet, the impact of biocrusts on soil evaporation lacks a mechanistic understanding of the biological processes that modify the crusts’ physical properties. We used controlled laboratory experiments, field observations, and mechanistic modelling to determine the impact of biocrusts on evaporation dynamics and subsurface thermal regimes. Our experiments were conducted with bare soil and different types of biocrusts along the ecological succession of the Succulent Karoo desert, South Africa. The preliminary results highlight how different thermal and radiative properties of the crusts affect evaporation rates and heat transfer into the soil layers beneath. Furthermore, active water uptake and storage by biocrust organisms result in water redistribution, which shapes energy balance during diurnal cycles. We conclude from the mechanistic model that biocrusts can accelerate the vertical transport of substrates at the cost of evaporative water loss. Thus, biocrusts may have evolved to modify soil physical properties for balancing nutrient turnover and water usage in global drylands highlighting their crucial roles in regulating mass and energy exchanges over terrestrial surfaces.
Modelling Microclimatic Benefits of Urban Green Spaces: Insights from ENVI-met Simulations in Augsburg, Germany
Authors: Simon Jonathan , Rathmann Joachim , Oster Jacqueline , Stocker Max , Falkenrodt Lisa-Marie , André Elisabeth , Mahesh Bhargavi , Can Yekta Said , Dietz Michael , Philipp Andreas , Beck Christoph
Published: March 2024

With two thirds of the world's population expected to live in urban areas by 2050, the exacerbation of the urban heat island effect is a critical challenge, affecting thermal comfort, public health, and air quality. Urban green spaces (UGS) emerge as pivotal tools for mitigating these adverse effects. They provide essential ecosystem services, including thermal comfort, shade, pollution control, carbon storage, and water cycling. In addition, UGS provide city-dwellers with opportunities for recreation, social interaction, and aesthetic inspiration.This study, funded by the German Research Foundation under contract 471909988, uses ENVI-met, a three-dimensional, grid-based microclimate model, to examine the positive microclimatic and biometeorological effects of UGS in different vegetation-dominated urban areas. The latest fractal-based L-tree (Lindenmayer system) representation in ENVI-met V5 provides a more nuanced representation of trees, categorised by tree species, considering variations in leaf area density within the tree crowns and the structurally correct representation of the tree skeleton.Focusing on UGS in Augsburg, Germany, including an urban park and different urban forest sites such as a mixed forest, a pine forest, a beech-dominated forest and a heath, the study examines the hypothesis that L-trees provide more accurate microclimate models than grid-based 3D-plants of older ENVI-met versions. The investigation considers the influence of spatial resolution, tree species, tree shapes, and tree heights on modelling precision. Additionally, the study investigates whether UGS heat mitigation is more pronounced in summer than in other seasons and how much it is influenced by area size, vegetation density, and study site. The spatial extent of the model areas is approximately 0.4 km² - 1.0 km² with a spatial resolution of 2 m - 5 m. We expect that the microclimatic impact of tree species composition within an UGS may be negligible, but could nevertheless influence subjective thermal comfort, aesthetic inspiration, and health-related parameters. These aspects are the subject of two further parts of the study, which deal with the objective health effects and the subjective perception of different UGS.Validation of microclimate model results includes field measurements using Kestrel 5400 heat stress trackers and HOBO MX2301A loggers. The study collected participant health and survey data during thermal walks through the UGS study sites, using wearable devices and questionnaires, to further validate various biometeorological effects and subjective perceptions. The research contributes to the advancement of microclimate modelling in urban parks and forests and provides insights crucial for optimizing ecosystem services of UGS to enhance urban resilience and promote sustainable development.
A Trigger for Transformation? Exploring Leverage Points to Bridge Top-Down and Bottom-Up Approaches in Flood Risk Management
Authors: Heinzel Christine
Published: March 2024

Natural hazards, particularly floods, pose significant threats to societies, demanding effective risk management strategies. In some nations, such as China and Vietnam, flood risk management historically followed a predominantly top-down approach, with limited citizen involvement in decision-making processes. Despite past success of this approach in minimizing losses, the escalating frequency and intensity of floods, driven by climate change, raise questions about solely relaying on conventional methods. In addition to or due to a lack of governmental initiatives, individuals and households often employ their own distinctive adaptation approaches, demonstrating a form of "bottom-up resilience". Without idealizing either approach, integrating aspects of both strategies and ultimately initiating a transformation of flood risk management is necessary to prevent exceeding capacity limits. However, there is still a profound lack of understanding how to genuinely enable transformation, especially in practical terms. Due to their potential to facilitate change, leverage points – places to intervene within a complex system – are becoming increasingly important in system research as a lens for evaluating and planning interventions that support transformation. However, existing research rarely considers leverage points in the context of identifying interventions with transformative potential in flood risk management.This presentation attempts to fill the gap in research by providing a framework for identifying deep leverage points crucial in the intricate dynamics among individuals, communities, and governments in flood risk management, while acknowledging the challenges, limitations and possibilities inherent in bridging top-down and bottom-up approaches. To overcome the gap between theory and practical implementation, the utilization of an Agent-Based Model (ABM) is proposed to simulate and analyze the impact of concrete interventions at the identified leverage points. An expected result from the ABM includes more in-depth knowledge on the effectiveness of trainings or platforms for information exchange, and about responsibilities within communities as an entry point to enhance community resilience to floods. The model results will provide a tangible and dynamic representation of the potential outcomes of integrated strategies, offering valuable insights for policymakers, researchers, and practitioners alike.
Influence of Intermittency on the Energy Transfer Rate of Solar Wind Turbulence
Authors: Wu Honghong , Huang Shiyong , Wang Xin , Yang Liping , Yuan Zhigang
Published: March 2024

The intermittency in the solar wind turbulence influences the anisotropy of the spectral index and the scaling of multiorder structure functions. However, its influence on the energy transfer rate remains unclear. Here we identify the intermittency using the partial variance of increments method for the magnetic field data measured in the fast solar wind by the Ulysses spacecraft. We study the anisotropy by distinguishing the sampling direction using the angle θRB between the local magnetic field and radial direction. We analyze the multiorder structure function analyses  and describe the role of intermittency in the framework of log-Poisson cascade model. We find the isotropic scaling with a complete removal of intermittency. We compare explicitly the anisotropy of the energy transfer rate before and after removing the intermittency for the first time. We find a distinct anisotropy with a cascade enhancement in the direction perpendicular to the local magnetic field. The removal of the intermittency greatly weakens the anisotropy by mainly reducing the perpendicular energy transfer rate. Our findings suggest that the intermittency effectively enhances the energy transfer rate, in particular in the perpendicular direction in the solar wind turbulence.
Studying the global propagation of gravity waves generated by the Hunga Tonga-Hunga Ha‘apai volcanic eruption from meteor radar observations and the High-Altitude General Mechanistic Circulation Model
Authors: Stober Gunter , Vadas Sharon , Becker Erich , Liu Alan , Kozlovsky Alexandre , Janches Diego ,   HTHH Meteor radar and HIAMCM GW analysis team:
Published: March 2024

The Hunga Tonga-Hunga Ha‘apai (HTHH) volcanic eruption on 15th January 2022 was an unprecedented event and a unique opportunity to investigate volcanic-caused gravity waves (GW) and their global propagation. In this study, we have combined all the available meteor radar observations and data analysis to identify the HTHH GW in the observations. Our results are compared to model-based wind perturbations from HIAMCM of secondary waves that are forced by the GW model MESORAC using GOES-17 observations. Furthermore, we leverage the GW polarization relations to identify different wave features in the observations and perturbation runs with HIAMCM. There is a remarkable agreement in the observed phase speeds for the eastward and westward GW propagation between the observations and HIAMCM wind perturbations indicating that the mesospheric HTHH GW are explainable by secondary waves generated by breaking of the primary GWs from the eruption. We also shed some light on the importance of the quasi-2-day wave on the HTHH GW propagation.
Airborne and in-situ measurements of wave-ice interactions in the Lower St. Lawrence Estuary
Authors: Villefer Antoine , Sutherland Peter , Lenain Luc , Dumont Dany
Published: March 2024

Decreasing sea ice cover in the Arctic Ocean is leading to an increase of surface wave energy.  This means that waves are becoming more important to Arctic dynamics, and so understanding their interactions with sea ice is a key question for Arctic oceanography. This work presents a unique set of simultaneous observations of wave-ice interactions during an episode of ice formation and wave generation. Airborne remote sensing observed the sea and ice surface using scanning lidar data, and infrared and hyperspectral imagery. Concurrently, an autonomous catamaran measured atmospheric fluxes, near-surface turbulence, temperature, and currents. During January 2023, this instrumentation was deployed in the fetch-limited natural laboratory of the Lower St. Lawrence Estuary in order to address the questions of how ice-forming conditions influence wave generation and how ice floes attenuate wave energy. These observations are used to develop understanding of the physics of wave-ice interactions and assess the ability of spectral wave models to reproduce them.  Implications for future models and larger-scale applications will be discussed.
Utilizing surface-based observations from the Micro Pulse Lidar Network (MPLNET) for validation of space-based satellite missions
Authors: Lewis Jasper , Campbell James , Dolinar Erica , Lolli Simone , Stewart Sebastian , Belcher Larry , Welton Ellsworth
Published: March 2024

Starting with the Lidar In-Space Technology Experiment (LITE) in 1994, spaceborne lidars have provided highly detailed global views of the vertical structure of clouds and aerosols. And since that time, surface-based lidar, well as aircraft lidar, have been used for validation through correlative measurements. While the validation of space-based lidar systems by surface-based lidar observations is not straightforward, protocols for doing so are well-established and have shown good agreement in many instances.     The Micro Pulse Lidar Network (MPLNET) is a federated, global network of Micro Pulse Lidar systems deployed worldwide to measure aerosol and cloud vertical structure, and mixed layer heights. The data have been collected continuously, day and night, for more than 20 years from sites around the world with multiple sites containing 5+ or 10+ years of data. MPLNET is also a contributing network to the World Meteorological Organization (WMO) Global Atmospheric Watch (GAW) Aerosol Lidar Observation Network (GALION). The use of common instrumentation and processing algorithms within MPLNET allow for direct comparisons between sites. Thus, long-term MPLNET measurements can be used to verify the fidelity of geophysical parameters measured throughout the lifetime of individual satellite missions (e.g. CALIPSO, CATS, EarthCARE, CALIGOLA, and AOS) and provide a metric for intercomparisons between different space-based lidar missions when gaps between satellite missions occur.In this presentation, we use multiple years of comparisons between MPLNET and the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) flown aboard CALIPSO. For these comparisons, we use newly developed Level 3 MPLNET products consisting of monthly, diurnal statistics for cloud and aerosol retrievals covering a representative range of conditions and locations. Furthermore, we compare top-of-the-atmosphere cirrus cloud radiative forcing derived from these two complementary platforms. Finally, using results from an upcoming validation rehearsal, we demonstrate how these procedures will be utilized during the EarthCARE mission, scheduled to launch in May 2024.    
The 19 May 2023 tsunami near the Loyalty Islands captured by the new SWOT satellite
Authors: Faugère Yannice , Roger Jean , Delepoulle Antoine , Dibarboure Gerald , Hebert Helene
Published: March 2024

During the last decades, trans-oceanic tsunamis have been captured by satellite altimeters on several occasions. The largest event ever measured by an altimeter was the 2004 Indian Ocean tsunami, captured by Jason-1, Topex/Poseidon, GFO and Envisat altimetry missions flying at that time  The new altimetry mission SWOT (Surface Water and Ocean Topography) developed by NASA and CNES, the US and French Space agency respectively, was launched in December 2022. SWOT embarks a novel instrument, a Ka-band Radar INterferometer (KaRIN), providing a 120 km wide swath Sea Level. On 19 May 2023, SWOT was able to measure the tsunami generated by the Mw 7.7 earthquake which occurred southeast of the Loyalty Islands (southwest Pacific Ocean) at 02:57:03 (UTC). SWOT flew over the region about 1 hour after the earthquake and captured the tsunami signature in several locations. For the first time, a 2D mapview image of the height of tsunami wavetrain was measured by a satellite. The tsunami generation and propagation have been simulated using COMCOT model, using source parameters derived from seismic observations and empirical laws. Preliminary simulation results show that a simple fault plane with uniform coseismic slip allows to reproduce the regional coastal gauge and oceanic DART station records with a relatively good level of confidence, considering that the earthquake rupture was strongly not-double couple according to USGS. An array of virtual gauges was designed to cover the satellite pathway, allowing to extract the dynamic representation of the tsunami wavefield corresponding to the satellite propagation time (i.e., the sea surface deformation is observed over a period of time of several minutes, instead of being static at a given time). Comparison between the SWOT sea surface measurement and the simulation result is satisfactory, showing a good agreement between the location of the first wave peaks (propagating toward the southwest and the northeast, respectively), their amplitude and phase. The objective of this study is first to present this unprecedented observation, and to analyze the level of consistency with simulations.
Navigating the Biogeography of Short-forests in Global Drylands
Authors: Dong Xiaoxue , Liu Xinyu , He Xiao , Chen Ning , Zhao Changming
Published: March 2024

The canopy height is pivotal in sustaining carbon cycling and upholding the ecological and biodiversity functions, which is also true or particularly the case for dryland ecosystems. Meanwhile, restorations in drylands have seen massive short-forests because of various reasons like insufficient water input. This study is committed to an exhaustive exploration of the biogeographic distribution and pivotal unknown determinants of short-forests in global drylands, offering indispensable insights for devising conservation strategies tailored to dryland forest vegetation. Here we divide satellite global dryland forests into the Tall-forests (17.30 ± 3.00 m) and the Short-forests (9.24 ± 2.57 m). The short-forests are ubiquitously distributed in global drylands, consist of 8.17% planted forests and 91.83% natural forests. These short-forests predominantly occur in ecosystems characterized by substantial climatic (temperature, precipitation) variations, impoverished soil textures, frequent human activities, and moderate to high elevations. Notably, within the short-forests, limitations on the canopy height of the natural forests appear to reach threshold values in specific factors earlier than in the planted forests such as Mean temperature of warmest quarter (11.73 ℃ vs. 12.64 ℃). Our discoveries explicate a nuanced comprehension of dryland short-forests, potentially serving as a crucial guide for informing future ecological restoration and sustainable management practices therein.
Health-relevant compound ground-level ozone and temperature events in Europe
Authors: Hertig Elke , Kaspar-Ott Irena
Published: March 2024

Ground-level ozone is a major air pollutant harmful for human health and there are concerns that ground-level ozone will increase over Europe under climate change despite efforts for a rigorous air pollution control. In addition, high levels of ground-level ozone often occur in combination with high air temperatures, for instance under persistent anticyclonic conditions in summer. Due to climate change heat events such as hot days and heat waves are also increasing. Thus, ground-level ozone health risks could combine with increased health risks from heat exposure.Changes in the atmospheric chemistry from increased biogenic volatile organic compound emissions, faster chemistry kinetics, and faster peroxyacetyl nitrate decomposition as well as enhanced stratosphere-troposphere exchange, changes of the large-scale atmospheric circulation and synoptic patterns, increased stagnancy, and changes of atmospheric humidity may lead to increases of ground-level ozone in the scope of climate change. For Europe regional differences exist. For instance, over central Europe there is a strong relationship with meteorological conditions, while over southern and northern Europe the influence of ozone persistence and hence precursor emissions is comparably strong on ozone exceedances.The present contribution comprises relationships of ground-level ozone and temperature with the atmospheric circulation, changes of health-relevant ground-level ozone and temperature events under future climate change as well as the connection of ground-level ozone and temperature with human health outcomes.  
 Hailuogou Glacier activities during the past six centuries inferred from tree rings and 14C dating
Authors: Zhu Haifeng , Xu Peng , Zhu Xiaolong
Published: March 2024

This paper presents a dendroglaciological study of Hailuogou Glacier, a maritime glacier in Hengduan Mountains, southwest China. We used tree-ring data collected from the glacier forefield, including buried wood and oldest living trees on moraine ridges, to reconstruct the glacier fluctuations during the past six centuries. The tree-ring data were combined with radiocarbon dating and remote sensing interpretation to determine the ages of moraine ridges and glacial deposits. The results show that Hailuogou Glacier experienced five equilibrium stages since the Little Ice Age, with the most extensive advance around 1760s AD and the most rapid retreat since the 20th century. The glacier fluctuations were compared with temperature and precipitation reconstructions from nearby regions, and the response relationship between the glacier and climate change was discussed. The paper demonstrates the potential of dendroglaciology to provide high-resolution records of maritime glacier history and its link to climate change in the Tibetan Plateau. The paper also contributes to the better understanding of the long-term relationship between the fluctuation of maritime glaciers and climate change, and provides a scientific basis and basic data for the prediction of glacier change under the future climate change scenario.
Calibration of a  hybrid sea-ice model based on particle and continuums mechanics
Authors: Mehlmann Carolin , Richter Thomas
Published: March 2024

Presently, climate models employ a continuum approach to describe sea ice. This approach assumes that statistical averages can be derived from a large number of ice floes. However, employing continuum rheological models at or below the scale of individual floes is only valid if the failure mode of a single floe aligns with that of an aggregate of floes. Initially, continuum models were designed for a grid resolution of 100 km. With recent advancements in computing power, sea-ice models are frequently operated at higher mesh resolutions, potentially leading to grid cells that no longer contains a representative sample of sea-ice floes.We are addressing these shortcomings of current continuum sea-ice models by developing a hybrid model. The idea of the hybrid approach is to nest a particle model into a continuum sea-ice model in order to predict sea ice on fine spatial scales in a region of interest. An important component of particle models is a drag law to describe the influence of ocean and atmospheric currents on the floes. Measurements obtained onboard the Polarstern expedition PS 138 have shown that the correlation cannot be described fully locally, in regions with strongly heterogenous ice cover. Instead, larger surrounding flows have a substantial effect on the motion of small ones. Detailed numerical simulations of idealised test cases do confirm these findings.   
Prospects for Jovian seismology with the Lenghu planetary telescope
Authors: Zou Yiqing , He Fei , Yao Zhonghua , Rong Zhaojin , Wei Yong
Published: March 2024

Abstract: Jupiter is one of the top priorities for deep space exploration in China and other countries. A crucial and remaining unclear scientific topic in Jupiter exploration is depicting the structure of its interior. This paper discusses the current understanding of Jupiter's interior, based on the current development of Jupiter exploration and research history. The present space-based and ground-based observation methods are reviewed, and their feasibility is analyzed. To gain insight into the internal structure of Jupiter, we propose to study Jupiter’s innards by planetary seismology. The ground-based observation, namely the Jupiter Seismologic Interferometer Polarization Imager (SIPI) in Lenghu, will be developed to obtain the Doppler velocity distribution on the surface of Jupiter and identify the oscillation signals. Lenghu has good observation conditions in China and even the world, providing a novel insight into studying the interior of Jupiter. This will also be the first study of the interior of Jupiter by using asteroseismology in China, which has significant implications for the exploration mission of Jupiter.Keywords: Jupiter seismology; Jupiter's interior; Jupiter model; Jupiter Seismologic Interferometer Polarization Imager (SIPI)
Mechanical characterization of Freiberger Gneiss (Reiche Zeche, Germany) from laboratory to field scale
Authors: Korkolis Evangelos , Kozlov Elisabeth , Adero Bernard , Renner Joerg
Published: March 2024

Reservoir rock properties play an important role in the overall efficiency of petrothermal systems. Potentially interesting target formations for such systems include igneous and metamorphic rocks. For such lithologies with typically low porosity values, pre-existing fractures and foliation emerge as possible controlling factors of their hydraulic and mechanical behavior, respectively. Understanding the hydromechanical behavior of the reservoir rock is vital for the planning, execution and monitoring of hydraulic stimulation and exploitation, and continued safe operation. We inferred the elastic behavior of Freiberger gneiss from millimetre to tens of meters scale from laboratory and field measurements. Laboratory measurements were performed on samples prepared from blocks collected in the Reiche Zeche mine in Freiberg, Germany, and on cores retrieved from boreholes, drilled to perform hydraulic stimulation experiments as part of the STIMTEC (STIMulation TEChnologies) project. Controlled-source, P- and S-wave ultrasonic measurements were performed on samples and cores at room pressure and temperature conditions, covering a wide range of angles between wave-propagation direction and foliation, to characterize the degree of mechanical anisotropy of the gneiss. Magnitude and anisotropy of P-wave velocities determined from the laboratory measurements on the cores are in broad agreement with velocities calculated from in-situ sonic log measurements and active ultrasonic transmission experiments  (Boese et al., 2022) representing travel path lengths from meter to decameters in the rock mass, with a mean fracture distance of decimeters. At elevated pressures, ultrasonic measurements on cylindrical samples suggest the dominance of foliation over microcracks in determining the elastic behavior. The lack of a substantial reduction in velocities, deduced from in-situ active and passive microseismic analyses (Boese et al., 2022), except in highly deformed volumes, constrains the stiffness of the in-situ fractures.ReferenceBoese, C. M., Kwiatek, G., Fischer, T., Plenkers, K., Starke, J., Blümle, F., Janssen, C., and Dresen, G.: Seismic monitoring of the STIMTEC hydraulic stimulation experiment in anisotropic metamorphic gneiss, Solid Earth, 13, 323–346, https://doi.org/10.5194/se-13-323-2022, 2022.
Exceptional bright OH airglow night at Cerro Paranal, Chile, with high wave activity and sudden brightness depletion
Authors: Hannawald Patrick , Schmidt Carsten , Wüst Sabine , Smette Alain , Bittner Michael
Published: March 2024

The dynamics in the atmosphere, especially the upper mesosphere and mesopause are significantly driven by atmospheric gravity waves. OH airglow offers an unique possibility to observe atmospheric dynamics in this altitude region with a high spatio-temporal resolution simultaneously using imager and spectrometer systems. Especially, characteristics of gravity waves as well as features like wave breaking and wave-wave interaction can be observed. Spectroscopic observations allow observing rotational temperature changes. Thus, both instrument types complement each other very well.Since November 2022 two airglow imagers (FAIM) and one airglow spectrometer (GRIPS) with high temporal resolution (1 image every 2 seconds, 1 spectrum every 15 seconds) started routine observations during each night in cooperation with and at ESO’s Very Large Telescope (VLT) in the Atacama Desert at Cerro Paranal, Chile (24.6°S, 70.4°W).During the night from 31st July to 1st August 2023 we observed an exceptional bright night that is much brighter than any other we observed so far: a single wave front propagates from West to East with an observed phase speed of about 60m/s. After the passing of the wave front the OH intensity decreases by around 50% within only one hour. Pronounced wave activity of small-scale waves is observed especially before the passing of the event. Similar events in literature are often stated as “wall events”, but seem to occur very rarely in the extent observed.We present and interpret the wall event and discuss the observed phenomenon and its causes using data from multiple instruments and data sources.