bluuebunny/crossref_metadata_2025 huggingface dataset:
Cool Multiphase Plasma in Hot Environments
Authors: Antolin Patrick , Froment Clara
Published: February 2023

Cool plasmas (≈ 104 K) embedded in a larger, much hotter (>106 K) medium are ubiquitous in different astrophysical systems such as solar & stellar coronae, the circumgalactic (CGM), interstellar (ISM) and intra-cluster (ICM) media. The role of these multiphase plasmas has been highlighted in mass-energy cycles at all such scales, from thermal non-equilibrium (TNE) cycles in the solar atmosphere to precipitation-regulated feedback cycles that drive star and galaxy formation. The properties of the cool plasmas across these multiple scales is strikingly similar, intimately linked to the yet unclear but fundamental mechanisms of coronal and ICM heating and instabilities of thermal or other nature. The solar corona constitutes a formidable and unique astrophysics laboratory where we can spatially and temporally resolve the physics of such multiphase plasma. The multi-faceted and measured response of the solar atmosphere to the heating is exemplified by TNE cycles that manifest through EUV intensity pulsations and through the generation of cool coronal rain and prominences whose mysterious properties are like that of multiphase filamentary structure in the ISM and ICM or to molecular loops in the Galactic centre. Coronal rain also occurs across a wide energetic scale extending to flares, whose features seem recurrent in active stars but remains poorly investigated due to lack of multi-temperature coverage at appropriate resolution. The formation and stability-loss of prominences is of major importance to space weather and their ‘slingshot’ counterparts provide unique diagnostic capabilities to the wind mass-loss rate. These exciting new cross-disciplinary possibilities are part of a Heliophysics Decadal Survey white paper and call for a high-resolution multi-wavelength imaging and spectroscopic solar instrument able to capture the multithermal, dynamic and pervasive nature of the multiphase plasma in the hot solar corona.
Blueprint for a digital twin of a river basin
Authors: Pal Debasish , Ala-Aho Pertti , Ronkanen Anna-Kaisa , Marttila Hannu , Lotsari Ellisa , Korppoo Marie , Silander Jari , Blåfield Linnea , Alho Petteri , Uvo Cintia , Kämäri Maria , Kaartinen Harri
Published: February 2023

Digital twins are part of ongoing digital transformation to test, monitor, and maintain physical environments virtually. The collaboration of smart measurement sensors, advanced communication networks, cloud data storage capacity, and cutting-edge computing techniques has the potential to create a digital twin of a river basin with greater physical, spatial, and temporal scalability. The digital twin is defined as a realistic virtual representation of the physical river basin that aids in improved decision-making through real-time data connectivity, association, and relationship. Because of the continuous bidirectional interactions between virtual and physical entities, the digital twin is unique to the physical river basin. The digital twin has the advantage of adapting to changing real-time river basin characteristics, resulting in increased operational efficiency, better uncertainty quantification, early warning detection, and identification of emergency management. By imagining smart river basin management via the digital twin concept, we are venturing into uncharted territory, with the goal of improving the ecological status of a river basin by balancing environmental and socioeconomic interdependence while minimizing natural resource depletion. This poster provides an overview of the concept, framework, methodology, and challenges involved in developing a digital twin of a river basin. The framework’s six dimensions are river basin, data, modeling, infrastructure, service, and connectivity. The methodology emphasizes the digital twin’s purpose identification, maturity spectrum, workflow architecture, technical core, data layers, model simulations, knowledge creation, and effective application. We discuss the key services provided by the digital twin for the river basin, as well as its future prospects for autonomous control in the physical river basin.
Simulating the hydrological impacts of intensive Soil and Water Conservation Measures in the Yellow River Basin Using a Distributed Physically-based Model
Authors: Yan Zihan , Lei Huimin , Yang Dawen , Gao Haidong
Published: February 2023

Intensive Soil and Water Conservation (SWC) has taken place in the Yellow River basin (YRB) to control soil erosion and river sediment, it has altered the eco-hydrological processes and particularly led to the runoff reduction. However, the SWC are rarely simulated explicitly in the hydrological models of the YRB. In order to understand its hydrological impacts, this study developed a SWC parameterization scheme in an existing distributed physically-based model (GBEHM). The hillslope SWC was parameterized as additional surface storage capacity and simulated together with hillslope hydrological processes. The check dams along the river networks were parameterized as reservoirs and simulated together with the flow routing. The improved model (GBEHM-SWC) had been calibrated and validated comprehensively using the observed river discharge and remote sensing-based evapotranspiration. The annual precipitation and runoff significantly decreased during 1982-2000 at the rate of -4.3 and -1.0 mm/yr, respectively. In the following period 2001-2019, the precipitation recovered at 3.2 mm/yr with a slight increasing in runoff at 0.2mm/yr. Compared to the previous period, the annual average precipitation and temperature increased by 27.3 mm and 0.85 ℃, whereas the observed runoff decreased by 4.3 mm. Therefore, we applied the GBEHM-SWC to quantify the impacts of climate change and SWC in the YRB, spatially and temporally. The SWC contributed to the annual runoff reduction by 3.8 and 3.7 mm (or 2.84 and 2.74 billion m3), respectively, in which the hillslope SWC measures accounted for 51% of the annual runoff reduction. Without the append SWC measures, the annual runoff would increase by 2.9 mm (or 2.17 billion m3) in the recent period due to the precipitation increase. Hillslope SWC and river-networks SWC have their largest impact on runoff reduction in the Longmen-Sanmenxia section and Toudaoguai-Longmen section, respectively. The parameterization scheme developed for the distributed model is useful for the watershed hydrological simulation and prediction under the intensive SWC implementation.
Evaluation of precipitation variability over the Sierra de Guadarrama
Authors: González-Rouco Jesús Fidel , Greciano-Zamorano Emilio , García-Pereira Félix , Vegas-Cañas Cristina , Navarro-Montesinos Jorge , García-Bustamante Elena , Rodríguez-Camino Ernesto , Rodríguez-Guisado Esteban
Published: February 2023

Heterogeneity in the occurrence, amount, and distribution of precipitation in mountainous areas is relevant for water resources and stresses the need for high-altitude observations and high-resolution modeling over complex terrain. However, the harsh weather conditions and the complex terrain associated with these environments hinder a continuous monitorization and pose challenges for regional climate models.In this work, data from 37 stations located in the Sierra de Guadarrama and nearly lowlands, in Central Spain, and with altitudes ranging from 600 to 2200 m.a.s.l. have been studied. A few of the highest altitude sites belong to GuMNet facility (https://www.ucm.es/gumnet) and the rest to the Spanish Meteorological Agency (AEMET; https://www.aemet.es). These data have been compared to ERA5 reanalysis (https://confluence.ecmwf.int/display/CKB/ERA5) and to three different resolution (9, 3, and 1 km) outputs of a simulation of the regional climate model WRF (https://www.mmm.ucar.edu/WRF) during the period from 1990-2019. The comparison of the different data sources aims at characterizing the precipitation distribution over the area, assessing the goodness of ERA5, and the potential added value of the increasing resolution of WRF simulation in reproducing the observations.Results show that the increase in WRF resolution from 9 to 3 km always produces a better representation of precipitation, whereas the step from 3 to 1 km shows a significant improvement at the highest altitudes, but an overestimation of precipitation at low plain areas. The lack of added value in the simulation at the highest resolution is discussed in relation to the parameterization of cumulus precipitation. Also, an altitudinal gradient of precipitation is observed and can be traced to large-scale precipitation.
Hydrodynamic Processes due to a Series of Partially Spanning Logjams
Authors: Schalko Isabella , Flury Nathalie
Published: February 2023

Due to human intervention, many rivers worldwide exhibit sediment deficit as well as hydraulic and morphological degradation, resulting in the restoration of river habitat becoming a critical task. In Switzerland, the revised Waters Protection Act demands the restoration of 4,000 eco-morphologically impaired river kilometers by 2090. To meet this target, nature-based solutions such as engineered logjams are being implemented to increase flow heterogeneity and provide shelter and habitat for aquatic organisms. To optimize their design, it is crucial to improve our understanding of the physical and ecological interactions for habitat creation, while also considering the potential flood hazard.In this study, we performed a series of flume experiments on partially spanning logjams positioned in series. The experiments were conducted for different clearance distances between the installed logjams, logjam width, solid volume fraction, and flow Froude number. We analyzed the resulting flow velocity, water depth, and turbulent kinetic energy to quantify the flow heterogeneity and to evaluate the flood hazard.The results demonstrated that the backwater rise upstream of the first logjam was larger compared to the second logjam. Compared to previous experiments with single partially spanning logjams, the presence of the second logjam did not affect the backwater rise upstream of the first logjam. In addition, it was found that the backwater rise increased with increasing logjam width, resulting in a smaller logjam width being more beneficial from a flood hazard perspective. In contrast, a wider logjam led to a higher flow variability and the creation of two distinct flow regions downstream of the logjams. This result highlights the relevance to consider both flow variability and flood hazard aspects to design engineered logjams for river restoration projects.
Sea Ice Growth, Melt and Dynamics in an Increasingly Marginal Arctic
Authors: Frew Rebecca , Feltham Danny , Schroeder David , Bateson Adam
Published: February 2023

As summer Arctic sea ice extent has retreated, the marginal ice zone (MIZ) has been widening and making up an increasing percentage of the summer Arctic sea ice. The MIZ is defined as the region of the ice cover that is influenced by waves, and for convenience here is defined as the region of​ the ice cover between ice concentrations of 15-80%. The MIZ is projected to become a larger percentage of the summer ice cover, as the Arctic transitions to ice free summers. We use​ a sea ice-mixed layer model that has a prognostic floe size distribution model including brittle fracture and form drag. The model has been compared and calibrated to FSD observations, satellite observation of sea ice extent and PIOMAS. We compare the processes of ice volume gain and loss in the ice pack to those in the​ MIZ to establish and contrast the relative importance of processes in the pack and MIZ, and the changes as the summer MIZ fraction increases and the amplitude of the seasonal sea ice growth/melt cycle increases. We compare the components of the sea ice volume budget in the 1980s and 2010s and then between the 2010s and the 2040s where almost the entirety summer sea ice cover has become MIZ.  
Breaking threshold and energy dissipation in solitary waves in a depth transition
Authors: Mostert Wouter , Boswell Hunter , Yan Guirong
Published: February 2023

Energy dissipation due to the breaking of surface waves remains an important open topic in both the open ocean and in coastal waters. Here we will discuss similarities between the deep- and shallow-water regimes. To do this, we first present data from direct numerical simulations of shoaling and breaking solitary waves in bathymetric depth transition. In an abrupt depth transition, we investigate the influence of the severity of the depth transition on whether the incident wave will break, finding good agreement with experimental data of Losada et al. (1988). We next investigate the energy dissipation rate in a gradual, linear depth transition. The resulting dataset is compared with an array of existing physics-based scaling arguments, and finds especially good agreement with an inertial model of Mostert & Deike (2020). We then discuss possible scaling approaches for understanding breaker dissipation in shallow water and draw comparisons with deep-water data and models. We will conclude with some insights towards a potential universal breaking parametrisation.
Remote Sensing of Biodiversity – Current Challenges and Future Prospects
Authors: Schweiger Anna K.
Published: February 2023

Biodiversity science is entering a new era. Years of effort by the scientific community are culminating in recent and upcoming launches of satellite systems specifically designed for global biodiversity assessment and monitoring. In addition, the Kunming-Montréal Global Biodiversity Framework, the most ambitious international agreement addressing biodiversity loss, is pushing for biodiversity and ecosystem protection, restoration and better management to occupy more prominent positions on global political agendas. It is clear by now that we need remote sensing to assess the status and monitor biodiversity globally and repeatedly. However, global biodiversity observatory systems need to combine remote sensing with ground observations to develop reliable and intepretable products. In this talk, I will try to summarize the current status and potential future directions of remote sensing of biodiversity across spatial, temporal and biological scales. The focus of my talk will be plant spectroscopy, which is based on the physical and physiological connections between plants and light. I will discuss the ways in which integrating ecological theory with measurements across spatial and temporal scales allow for a better understanding of what aspects of biodiversity global satellite systems are capable of detecting on the ground. I will also provide examples of remote sensing studies investigating the diversity of taxonomic groups other than plants through their connection with particular vegetation characteristics. Future advances in the field of remote sensing of biodiversity will benefit more than ever from diverse teams, global cooperation and collaborations across disciplines, including biology, geography, computer science and robotics. Now is the time to do our best work to help prevent and mitigate the negative consequences of biodiversity loss.
Impact of engineered logjams in enhancing performance of full floodplain restorations
Authors: Follett Elizabeth , Hankin Barry , Chappell Nick
Published: February 2023

Changes in storm frequency and intensity, linked to increases in drought and flooding, are expected to continue to rise due to climate change. To promote provision of ecosystem services and mitigate climate change impacts, international interest has grown in use of nature-based solutions for climate adaptive management of surface water. Nature-based solutions for natural flood management include large wood additions, construction of engineered logjams, and implementation of full floodplain restorations, in which stream water formerly directed to an incised channel is allowed access to a restored floodplain with increased hydraulic roughness. Here, we examine the role of engineered logjams in enhancing water storage on a full floodplain restoration site (Lowther Estate, Penrith, Cumbria, UK), at which water formerly directed to an artificial diversion channel has been allowed to access its historic route across a restored floodplain. A time record of discharge entering and exiting the site is obtained from calibrated flumes. We present results evaluating the floodplain restoration performance in relation to vegetative drag and event magnitude. The potential is examined for engineered logjams in combination with existing vegetation to enhance water storage during major flood events, while allowing reduced storage during routine conditions. Reduction in hydrograph peak magnitude and increase in time delay of the peak are evaluated using a 1D network model exploring jam spacing and structural common metric, with the accumulation of wood pieces acting as a porous obstruction. The effect of jam spacing and structure is explored and related to the observed range of local wood piece characteristics, yielding recommendations for design and maintenance of full floodplain restoration interventions.
Applying quantitative methods to identify and distinguish between extensional and compressional ridges in subaqueous landslide deposits
Authors: Barrett Rachel , Held Philipp , Micallef Aaron , Gross Felix , Berndt Christian , Krastel Sebastian
Published: February 2023

Morphometric features within subaqueous landslide deposits provide critical information about the process of failure – a factor that is directly linked to the hazard potential of a landslide. However, some morphometric features, such as compressional and extensional (spreading) ridges, have similar geomorphology even though they form through very different processes. Identification and classification of these ridges in subaqueous landslide deposits is typically carried out manually and, as such, is heavily dependent on interpreter experience and bias. In this study, we make use of bedform analysis techniques typically used to identify seafloor features, such as ripples and dunes, to quantitatively characterize and distinguish between spreading and compressional ridges in subaqueous landslide deposits in a variety of settings, both lacustrine and submarine. Our approach involves identifying local maxima and minima, grouping them using neighbourhood analysis, and then calibrating these ridges using a series of closely-spaced perpendicular profiles following existing methods for bedform analysis. We then compare the metrics (including wavelength, height, slope, symmetry, and sinuosity) of the two kinds of ridges, and use these to distinguish between them. The application of quantitative, semi-automatic methodology such as this is critical to enable a move towards a less subjective interpretation of subaqueous landslide deposits, and to ensure accurate identification of features formed through different morphological processes.
Space environment and Poynting fluxes around the Trappist-1 exoplanets and effects of coronal mass ejections on their habitability
Authors: Elekes Filip , Saur Joachim , Grayver Alexander
Published: February 2023

Trappist-1 is an extraordinary planetary system with 7 confirmed terrestrial exoplanets, some of which may lie in the habitable zone around the central M dwarf star. M dwarfs are magnetically very active and probably emit a stellar wind that interacts with the planets. Stellar winds and their interaction with planetary atmospheres and magnetospheres, if the planets are magnetized, affect the energy budget of their surroundings and ultimately the habitability of those planets. During coronal mass ejections (CMEs) intersecting the planets the exposure to increased stellar wind pressure, density and velocity might result in significant heating of the planets surroundings and interior (Grayver et al. 2022)[1]. We aim to better understand the space environment around the Trappist-1 planets and their interaction with the surrounding stellar wind. We perform magnetohydrodynamic simulations to study the interaction of the planets with the stellar wind. We also study the effect of CMEs on the energy budget of planetary atmospheres and magnetospheres, their heating, and possible effects on exoplanet habitability.References
A. Grayver et al., The Astrophysical Journal Letters 941, L7 (2022)
Assessing soil moisture and salinity dynamics in an irrigated olive orchard using the HYDRUS 2D/3D model
Authors: Morianou Giasemi , Tzerakis Konstantinos , Psarras Georgios , Kourgialas Nekatrios
Published: February 2023

Irrigated agriculture is the world’s largest water consumer, while at the same time water resources are under increasing pressure from rapidly growing demands and climate change. In Greece, about 45% of the total cultivated area is being irrigated and groundwater is the main source of irrigated water supply. Due to the scarcity of fresh water, the islands of Greece face serious problems by saltwater intrusion in coastal aquifers. In these areas, it is a common practice to utilize saline groundwater in irrigated olive orchards. Thus, estimation of all water fluxes temporally and spatially within and out of the crop root zone, and evaluation of issues like salinity are necessary to fully assess the efficiency of irrigation systems and methods. Simulation models can be used to investigate these issues over several seasons and scenarios. In this study, HYDRUS 2D/3D was used to evaluate data measured during one season (2022) in an olive (Olea europaea) orchard in Crete, Greece. The model efficiency was assessed by comparing model simulations against the observations of θ and EC obtained by an IoT-based monitoring system installed in the frame of HORIZON 2020-Agricapture project in irrigated fields of the Merabello area (Eastern Crete). The system includes the monitoring of soil moisture and atmospheric sensors, providing information on irrigation scheduling to farmers. Three IoT-devices were established in the study field, connected with an advanced soil moisture, temperature, and electrical conductivity sensor Teros12 (METER group, Inc. USA) installed at 0.3 m depth. Meteorological data collection was possible through a weather station (Davis Vantage Pro2™) installed in the area. Comparison of simulated against observed θ and EC showed a good precision of HYDRUS 2D/3D model for olive trees irrigation, with the Nash-Sutcliffe and the Root Mean Square Error (RMSE) being within the acceptable ranges. Model results can be used to improve the decision-making IoT system and advise farmers on various aspects of irrigation under saline environment, as, for example, in scheduling irrigation events for leaching salts, to avoid crop damage.The authors acknowledge contribution of the AgriCapture CO2 - Horizon 2020 project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101004282.
VirES for Swarm & Virtual Research Environment: Disseminating Swarm data, models, and tools
Authors: Pačes Martin , Santillan Daniel , Smith Ashley
Published: February 2023

The VirES service can be described as an ecosystem: the VirES server provides robust API-based access to both data and models derived from Swarm measurements; the VirES web interface provides visual point-and-click access [1]; the viresclient Python package provides the basis for a programmatic workflow and connection to the scientific Python landscape [2]; the Virtual Research Environment (VRE) provides a ready-to-code Jupyter environment to empower researchers to quickly start writing and running code using the latest Python packages [3].

In tandem with the evolution of the Swarm product portfolio, VirES evolves to provide access to and visualisation of new data products as they are published. Beyond this, Swarm activities are shifting away from static data products and toward on-demand processing and tools. We support development and dissemination of such tools in a scientist-led way through the VRE. These take the form of both computational notebooks and of Python packages.

With a growing number of data sources, both Earth-bound and orbital, it is critical to enable easier multi-dataset scientific workflows. At the same time, there is a multiplicity of research software projects, complex to navigate and make use of. We are tackling these issues through adoption of the Heliophysics API specification (HAPI [4, 5]), and coordination with the Python in Heliophysics Community.

[1] https://vires.services
[2] https://viresclient.readthedocs.io
[3] https://notebooks.vires.services
[4] https://hapi-server.org
[5] https://vires.services/hapi
Biogenic volatile organic compounds emitted by European Temperate forests: How do broadleaf species react to frost and drought?
Authors: Pieber Simone M. , Molteni Ugo , Luo Na , Kalberer Markus , Faiola Celia , Gessler Arthur
Published: February 2023

Biogenic volatile organic compounds (BVOCs) are a highly complex and diverse set of chemicals emitted into the atmosphere by the Earth's biosphere [1]. Atmospheric oxidation of BVOCs affects atmospheric mixing ratios of CH4, CO, and tropospheric O3, and leads to the formation of Secondary Organic Aerosol (SOA) (i.e., submicron particulate matter). Atmospheric aerosol plays a crucial role in defining Earth's radiative balance and impacts air-quality [2]. Climate models project a further increase in the average global temperature for the next decades. Warm winters appear to lead to earlier leaf-out which may put trees at higher risks of late frost in spring and summer droughts are increasing in frequency and extent. The probability that a late frost and an extreme summer drought occurs in the same year is expected to increase and thus, how trees respond to and recover from the (double) stress will be important in determining changes in BVOC emissions composition and quantities. Climate warming may thus lead to changes in atmospheric chemistry, including SOA properties [3]. During 2022, we studied the impact of spring frost and summer drought on BVOC emissions from broadleaf seedlings. We exposed 2-year-old seedlings of 3 species (Quercus petraea, Quercus robur, Fagus sylvatica) to an artificial spring frost by keeping seedlings with leaves that were fully out at -5.5℃ for 3 hours at the beginning of May 2022. Subsequently we simulated a summer drought from early July through the end of August (50% water reduction). The BVOC emissions of QP, QR, and FS, were measured deploying a PTR-ToF-MS alongside a newly developed plant chamber system [4] in August 2022.
We address the following research questions in our conference contribution: 

How do BVOC emissions composition and quantities of broadleaf control trees (QP, QR, FS) compare to coniferous ones (studied during AccliMemo 2022 [4])?
How are the BVOC emissions of QP and FS modulated in response to a) late spring frost, b) summer drought,  and c) double stress?

 
References:
[1] Sindelarova et al. Global data set of biogenic VOC emissions calculated by the MEGAN model over the last 30 years, ACP, 14, 9317–9341, https://doi.org/10.5194/acp-14-9317-2014, 2014
[2] Seinfeld, John H. and Pandis, Spyros N.: Atmospheric Chemistry and Physics: From Air Pollution to Climate Change, 3rd Edition., Wiley, 1152 pp., 2016
[3] Smith, N. R. et al.: Viscosity and liquid–liquid phase separation in healthy and stressed plant SOA, Environ. Atmospheres, 1, 140–153, https://doi.org/10.1039/D0EA00020E, 2021
[4] Molteni, U. et al., 2023, EGU23 GA Abstract Nr. EGU23-14587
 
Acknowledgements:
SMP acknowledges funding by the Swiss National Science Foundation (SNSF) grant no. P400P2_194390.
Monitoring the effect of multiple scattering using Sentinel-1 SAR data: A case study of paddy fields
Authors: Salma Shaik , Dodamani Basavanand
Published: February 2023

For the purpose of defining soil moisture in vegetated areas, abstraction from vegetation-soil interactions must be taken into account, and it must be quantified based on multiple scattering effects, due to the various phases of agricultural crop and its effect on vegetation growth due to the wave signal effect. Entropy-alpha cluster-based (entropy and alpha band clusters are obtained by using K-means unsupervised classification) decomposition approach has been utilised using the Sentinel-1 SAR data to determine the principal scattering contributions from the soil and the vegetation in order to take the effects of plant-soil interactions into consideration. The variation of entropy and alpha is plotted in the target decomposition because the first and second eigenvalues of the covariance matrix for dual-pol data, which indicates a controversial second scattering mechanism. However, anisotropy must be taken into consideration in order to account the impact of vegetation-soil multiple scattering interactions.The entropy, alpha, and anisotropy bands of considered crop pixels were extracted, and examined the correlation of determination (R2) of crop pixels with each band of decomposition. The R2 for entropy-alpha was achieved less compared to alpha-anisotropy and entropy-anisotropy bands combination. Even though the R2 is high with anisotropy element, anisotropy indicates the presence of a second scattering mechanism and is particularly useful where entropy is high to improve scattering mechanisms. The coefficient of determination between the multiple scattering effects and the backscattering coefficient varies with the crop growth stage. During the initial stages of paddy crop, the R2 is very less whereas as the stage of crop changes, the R2 showed significant varaition at the late vegetative stage of paddy crop due to the vegetation-soil multiple interactions of wave signal. Hence, from the analysis, it is concluded that, the crops can contribute the multiple-scattering effect irrespective of the dominance of either vegetation or soil contribution, which needs to be properly accounted for retrieving soil moisture.
Heat extremes in scenario projections: the role of variability
Authors: Simolo Claudia , Corti Susanna
Published: February 2023

Heat extremes have grown disproportionately since the advent of industrialization and are expected to intensify further under unabated greenhouse warming, spreading unevenly across the globe. However, amplification mechanisms are highly uncertain because of the complex interplay between the regional physical responses to human forcing and the statistical properties of atmospheric temperatures. Here, focusing on the latter, we explain how and to what extent the leading moments of daily thermal distributions sway the future trajectories of heat extremes. We show that historical and future temperature variability are the key to understanding the global patterns of change in the frequency and severity of the extremes and their exacerbation over many areas. Variability is crucial to unravel the highly differential regional sensitivities and may well outweigh the background warming. These findings provide fundamental insights for assessing the reliability of climate models and improving their scenario projections.
Using GRACE Terrestrial Water Storage Data for Groundwater Flow Model Calibration of Alaşehir-Sarıgöl Sub-Basin, Turkiye
Authors: Batkan Elif Aysu , Çaylak Barış , Bayırtepe Mustafa Berker , Ören Ali Hakan , Elçi Alper
Published: February 2023

Water resources are under immense stress due to the continuous increase of anthropogenic and natural pressures. Therefore, effective water management backed by advanced tools and methods is essential for the sustainability of water resources. One of these tools is groundwater flow modeling, which can be used to estimate changes in groundwater storage. In this study, we propose an approach to improve groundwater flow modeling by supporting model calibration with remote sensing data. The approach is demonstrated on the Alaşehir-Sarıgöl sub-basin in the east of the Gediz River Basin, a water-stressed basin in western Turkiye. A MODFLOW-2005 based flow model is constructed to determine time series hydraulic head changes and aquifer storage. The model simulation period is from 2013 to 2021. The groundwater recharge input of the model is obtained by a remote sensing-supported water balance method (Batkan et al., 2022). Except for precipitation data measured at meteorological stations, other model parameters are remote sensing products. Evapotranspiration is obtained from the MODIS Global Evapotranspiration product (MOD16A2), and soil water content and runoff are obtained from the ERA-5 Land Model reanalysis dataset. Hydraulic parameters such as hydraulic conductivity and storage coefficient are determined as a result of the calibration of the groundwater flow model. Model performance is improved by using terrestrial water storage (TWS) data from NASA's GRACE mission in the calibration of the storage coefficient. TWS represents the total water content above and below ground in the unconfined aquifer, therefore data needs to be adjusted to obtain an estimate of groundwater storage. Streams in the region can be ignored as a contributor to the TWS as they are intermittent and have typically low discharges. The soil water content in the unconfined aquifer is determined using ERA-5 data. The calibrated model RMSE value is 7.4 m, which was subsequently improved to lower values after the conjunctive use of the GRACE-derived TWS data.Keywords: groundwater flow modeling, model calibration, remote sensing, GRACE, ERA-5Acknowledgment: This study is funded by the PRIMA program supported by the European Union under grant agreement No: 1924, project RESERVOIR (sustainable groundwater RESources managEment by integrating eaRth observation deriVed monitoring and flOw modelIng Results). 
The role of multiple time scales for rate-induced tipping phenomena
Authors: Feudel Ulrike
Published: February 2023

Many systems in nature are characterized by the coexistence of different stable states for a given set of environmental parameters and external forcing. Examples for such behavior can be found in different fields of Earth system, e.g. ecosystems and climate dynamics. As a consequence of the coexistence of a multitude of stable states, the final state of the system depends strongly on the initial condition.  The set of initial conditions which all converge to the same stable state is called the basin of attraction. In addition, the dynamics of complex systems is often characterized by the different time scales on which certain processes act. We show that the interplay of these different time scales is important particularly for the case of rate-induced tipping. This tipping phenomenon occurs when the rate of change of an internal parameter or an external forcing is varying on a different timescale as the intrinsic timescale of the system.  The system can track its original stable state under such time-dependent forcing as long as the rate of environmental change is slow. If this rate is larger than a critical rate the system will tip and obey a rather different dynamical behavior, either by approaching a different stable state or by visiting temporarily different parts of the state space.  We study the role of the relative size of the basins of attraction and the location of their boundaries in rate-induced tipping and demonstrate that the decision whether a trajectory tips or tracks the original stable state depends crucially on the changes in the basins of attraction, in particular their size and, more importantly on their boundaries, that also “move” in state space under a time-dependent variation of intrinsic parameters/external forcing.  This dependence is discussed for the two cases of smooth basin boundaries made up by the stable manifolds of saddle points and fractal basin boundaries where chaotic saddles embedded in the boundary influence the tipping of trajectories. 
Analysis of eruptive activity at Stromboli volcano through a continuous monitoring of multi-parameter geophysical data
Authors: Garcia Alexander , Zaccarelli Lucia , Sandri Laura
Published: February 2023

Recent eruptive activity at Stromboli is mostly characterized by persistent, Strombolian explosive activity from summit craters. Occasionally, so-called major explosions occur, and more rarely paroxysms take place, such as on 3 July and 28 August 2019. We analyze monitoring data recorded between 2016 and 2022 to identify and characterize patterns in multi-parameter time series (considering in particular seismic, geochemical, meteorological, and sea-level gauges), with special interest in analyzing patterns observed before and during the occurrence of major explosions and/or paroxysmal eruptions. In practice, (i) we implement algorithms to automatically identify families of seismic events using waveform features; (ii) we analyze the effect of oceanic microtremor on continuous and discrete amplitude-based measurements; (iii) we study the temporal and size distribution of event occurrences, and use this information to assess likely trends in eruptive behavior. Moreover, (iv) we use noise cross-correlations and auto-correlations to compute seismic velocity variations of the shallow crust. Multi-parametric measurements provide interesting insights in the temporal evolution of the eruptive activity at Stromboli; for example, correlated changes in the pattern at which events occur in time, patterns in the distribution of extreme, large events, and evidence of a decrease in seismic velocity, seem to be phenomena occurring before paroxysmal eruptions. Detailed analyses of the produced time series, including also pattern recognition techniques, are required for better revealing likely patterns and for better understanding and interpretation of observations. 
Evaluating CMIP6 models with a simple climatology score
Authors: Graff Lise Seland , Parding Kajsa M. , Landgren Oskar A.
Published: February 2023

When investigating multi-model ensembles it can be useful to evaluate model performance to make sure that the historical climate of the fields of interest is captured to a satisfactory degree. To this end we define a simple climatology score, based on the root-mean-square error (RMSE) of essential climate variables from the historical experiments of an ensemble of models participating in the sixth Coupled Model Intercomparison Project (CMIP6). We consider four key variables: near-surface temperature, precipitation, 850-hPa zonal wind, and 850-hPa air temperature. The focus is on monthly climatologies of global values, but we also explore the sensitivity of the scores to changes in the regions and seasons considered. The purpose of the score is to help identify models with relatively large errors in the representation of the variables of interest. This can be useful when considering models to include for storyline analysis or when selecting a subset of models for regional downscaling.
Low-cost air quality sensors: The good, the bad, and the ugly. Preliminary findings from the QUANT study
Authors: Lacy Stuart E , Diez Sebastian , Bannan Thomas J , Flynn Michael , Watson Nathan , Marsden Nicholas , Priestman Max , Edwards Pete M
Published: February 2023

Low-cost air pollution sensors (LCS) have a potentially vital role to play in tackling air pollution. Their affordability facilitates the creation of dense networks, which coupled with their intrinsic high time resolution offers a vast spatio-temporal coverage unlike that possible with conventional instrumentation, offering a paradigm shift in the way we measure key pollutants, evaluate health impacts of air pollution exposure and assess clean air policies. However, despite the availability of numerous commercial LCS products, there is limited current understanding as to their suitability for these tasks. The QUANT project aims to address this deficit in order to enable the use of LCS to support UK clean air ambitions. Over a period of three years, 52 commercial LCS instruments from 14 companies have been measuring real world air quality data in a range of UK urban environments, collocated with reference grade instruments. With the data collection period having ended in November 2022, there now exists a comprehensive dataset of measurements from multiple pollutants across a variety of LCS systems, differing in both the underlying sensor technology as well as the software layer that converts the noisy raw signals into meaningful concentrations.  This talk summarises the initial conclusions emerging from this study, highlighting the various factors that should be taken into account when considering LCS for a specific task, for example: the robustness of the calibration algorithm, variability between devices from the same company, how well the measurements transfer between sites, and differing response to meteorological conditions. To help make this knowledge accessible to a wider audience, a web-app is presented that can allow researchers and decision makers to interactively explore the dataset to assess the applicability of devices to their particular requirements.
The Hydrogen Upper Atmosphere of Uranus Seen Through Lyman Alpha Observations
Authors: Joshi Sushen , Roth Lorenz , Ivchanko Nickolay , Gladstone Randy , Lamy Laurent
Published: February 2023

Several aspects of Uranus’s upper atmosphere are not well understood. The temperature is substantially higher than can be explained by solar heating alone. Over the last three decades, it has been observed that the ionosphere is continuously cooling, beyond seasonal effects. Voyager 2 revealed a substantial H exosphere and atomic corona of Uranus extending several Uranus radii. Inspired by the cooling of Uranus’s ionosphere, we are interested in understanding how its H upper atmosphere changes over a long period of time. From 1998 to 2017, Uranus was observed in ultraviolet wavelengths using Hubble Space Telescope’s STIS instrument in several observing campaigns (before and after equinox at Uranus). We analyze this data at Lyman-alpha wavelength (121.56 nm) and do radiative transfer modeling to study variation in the H upper atmosphere. We present the evolution of the H upper atmosphere over this period that we understand from the preliminary radiative transfer modeling.
A high-performance integrated hydrodynamic modelling framework for large-scale multi-process simulation
Authors: Tong Xue , Liang Qiuhua , Zhao Jiaheng
Published: February 2023

Coastal cities are prone to the risks from multiple hazards, e.g., compound floods driven simultaneously by interactive fluvial, pluvial and coastal processes. The overland flow and flooding process of a compound event may further erode soil, move and carry along debris of different size, and pick up and transport pollutants to create secondary hazards to exacerbate the flood impact on assets and environment. When assessing and managing multi-hazard risk, it is essential to have a modelling tool that can depict in detail the flooding and associated processes. However, the traditional flood models seldomly consider and simulate the interactive rainfall-runoff-flooding and associated secondary hazard processes.This work aims to develop and test a high-performance portable modelling framework to simulate the flooding dynamics triggered by multiple drivers, as well as the relevant cascading processes, to support more comprehensive multi-hazard risk assessment and management. To simulate the complex flooding dynamics from multiple sources, the High-Performance Integrated hydrodynamic Modelling System (HiPIMS) developed at Loughborough University is adopted. HiPIMS solves the full 2D shallow water equations (SWEs) using a Godunov-type finite volume method, implemented with novel variable reconstruction and source term discretisation schemes to handle complex domain topography and wetting and drying to achieve stable and accurate prediction. HiPIMS is further implemented on multiple GPUs to achieve high-performance computing to support large-scale high-resolution simulations. In this work, a new version of more compatible and portable HiPIMS is developed by adopting PyTorch (https://pytorch.org) to distribute GPU threads and reconstruct input data and internal variables, making it easier for interfacing with GIS tools and data pre- and post-processing. To ensure the new HiPIMS is extendable to incorporate new modelling components to achieve multi-hazard and multi-process modelling, the main model code is encapsulated to provide interfaces with easy access to hydrodynamic information, i.e., water depths and velocities, for model coupling. Git (a distributed version control system for programmers to collaboratively develop source codes) is further employed to support long-term flexible model development and maintenance.The capability of the new HiPIMS is demonstrated and confirmed by application to 1) reproduce a surface water flood event driven by fluvial and pluvial processes across the 2500km2 Eden catchment in England; 2) initiation and propagating process of floating debris driven by highly transient flood waves; and 3) wash-off, transport and deposition of non-point-source pollutants driven by rainfall induced overland and flood flows over urban surfaces.
Climatic warming changes to Northern European extreme temperature processes over the past 500 years
Authors: Bruun John
Published: February 2023

One of the most telling effects of the weather and climate is the occurrence of rare extreme events. As extremes are typically sudden and climate variability is a slower process, it is important to assess how severe changes have become and to aim to understand why. As the climate dynamics of the mean state are altering, can we also establish accurately if there are systematic changes to the extreme temperature process? One main challenge for assessing such climate dynamic alterations across these time scales is how to analyse records across the pre-industrial paleo and instrumental eras of the past 500 years. This analysis focusses on Northern European temperatures and their mean state and extremes changes. The analysis is done using a form of Dominant Frequency State Analysis where the extreme process (modelled as a Generalised Extreme Value process) can be distinguished from the variation of the mean state. The methods used in this approach are generic and can be applied in any study of extremes provided there is data (instrumental, simulated or paleo-proxies) that is of sufficient quality. This work reports how the extreme temperature process properties for Northern Europe appear to have altered across 500 years and I’ll discuss the climate dynamics interpretation of these results.