bluuebunny/crossref_metadata_2025 huggingface dataset:
Ten years of operation of Swarm's absolute magnetometers, lessons learnt and prospect for the NanoMagSat nanosatellite constellation project
Authors: Hulot Gauthier , Coïsson Pierdavide , Chauvet Louis , Léger Jean-Michel , Jager Thomas
Published: February 2023

ESA Swarm satellites carry a magnetometry payload consisting of an absolute scalar magnetometer (ASM), a relative flux gate vector magnetometer (VFM), and a set of star trackers (STR). The primary role of the ASM is to provide precise 1 Hz absolute field intensity measurements, while the VFM and STR provide the additional data needed to accurately reconstruct the vector field. This magnetometry payload has provided a remarkable set of nominal vector data, which has extensively been used for multiple investigations, as illustrated by the many results presented in this session. Each ASM instrument, however, can also produce its own self-calibrated 1 Hz experimental vector data, or, when requested, 250 Hz scalar burst mode. Self-calibrated 1 Hz experimental vector data have routinely been produced ever since launch, and substantial amount of scalar burst mode sessions have now also been run, mostly since 2019, when the decision was made to run such sessions one week per month on both the Alpha and Bravo satellites. In this presentation, we will illustrate the added value both these datasets brought to the Swarm mission, with the self-calibrated 1 Hz experimental vector data contributing to improvement and validation of the nominal dataset, and the burst mode data bringing new science opportunities. We will also discuss the lessons learnt from operating the ASM instruments on Swarm and how these led to the development of an appropriate miniaturized magnetometry payload for the NanoMagSat nanosatellite constellation. This constellation project is currently under development in the context of the ESA Scout program, and aims at a launch in the near future for complementing and enhancing the science return of the Swarm mission.
Plasma-neutral gas interactions in various space environments beyond simplified approximations
Authors: Yamauchi Masatoshi , De Keyser Johan , Parks George , Oyama Shin-ichiro , Wurz Peter , Abe Takumi , Beth Arnaud , Dunlop Malcolm , Henri Pierre , Kucharek Harald , Marghitu Octav , Nicolaou Georgios , Shimoyama Manabu , Saur Joachim , Taguchi Satoshi , Tsuda Takuo , Tsurutani Bruce
Published: February 2023

The majority of the atmospheres of solar system bodies are composed of neutral gas, and hence their upper atmosphere are always partially ionized by the solar UV and collisions, allowing a complex nonlinear interaction with interplanetary plasma.  Thus, ion-neutral and electron-neutral interaction plays a key role in this transition regions (ionosphere for planets and moons). However, our current understanding of plasma-neutral gas interactions is very limited due to lack of observations with proper instrumentation and to the difficulty in making laboratory experiments (almost impossible to reproduce the ionosphere with low energy plasma).  Particularly the effect of small amount of neutral species in space above the exobase and the effects of electric charges on neutrals have been underestimated.  To advance our knowledge of these basic but still poorly understood interactions between plasma and neutral gas at key regions of energy, momentum, and mass exchange between the space and the atmosphere, we evaluate what kind of measurement package is needed for different solar system objects in a cost-effective manner.  We particularly focus on understanding the re-distribution of externally provided energy to the composing species through this interaction.  The presentation is based on a white paper submitted to ESA's Voyage 2050 (Experimental Astronomy, 2022), and related mission proposals to space agencies.  Here we skip the chemical aspect that is also mentioned in the white paper.Reference: https://doi.org/10.1007/s10686-022-09846-9
Testing the performance of different WRF planetary boundary layer parameterizations schemes in the precipitation simulation under different Weather Regimes
Authors: Martins Joana , Carvalho David , Rocha Alfredo , Cardoso Pereira Susana
Published: February 2023

Surface meteorology is dominated by atmospheric boundary layer processes. Due to their typical low spatial resolution, numerical weather prediction models are not able to explicitly resolve such sub-grid scale processes, and as such use physical parameterization schemes to implicitly take into account these processes' influence on atmospheric variables. It is well known that the performance of such physical parameterization schemes depends on the atmospheric state of each location, season, etc.This work aims to investigate the performance of six different WRF PBL parameterization schemes in the simulation of the precipitation over continental Portugal, under different weather regimes, or weather types. For this, a set of six weather regimes, which represent 96% of Portugal's atmospheric states were identified and for each WR, six different PBL parameterization schemes were tested.Preliminary results show that for the entire region, the lowest spacial mean difference between observations and simulations is shown by the TEMF scheme parameterization for the positive phase of the North Atlantic Oscillation (NAO +) and Scandinavian height Weather Regimes,  MYJ for Summer Pattern, Anti-blocking (AB) and negative phase of the North Atlantic Oscillation (NAO -), and ACM2 scheme for Blocking (BLO) Weather Regime.
Textural and compositional variation of carbonate minerals in the Newania carbonatites, Rajasthan, India
Authors: Singh Amritpaul
Published: February 2023

The Newania carbonatite complex (~1473 Ma) in northwestern India is one of the oldest carbonatitic occurrence in India. It is a plutonic complex, comprising of two types of carbonatites and fenitized aureole within host Untala granite of Banded Gneissic Complex. The two types of carbonatites present include: (1) magnesiocarbonatite, and (2) ferrocarbonatite. This study illustrates textural and compositional variation of carbonate phases present in magnesiocarbonatite. Magnesiocarbonatite is principally composed of dolomite-ankerite series carbonates and accessory magnesite-siderite series carbonates. Dolomite-ankerite series carbonates occur as coarse-to-medium-grained (>200 µm) subhedral-to-anhedral crystals, displaying three types of deformation textures: (1) equigranular mosaic fabric with frequent triple junctions, thick-to-thin twin lamellae and absence of strain-derived deformational changes; (2) elongated medium-grained crystals, oriented in one direction, having high aspect ratio and twin lamellae density; and (3) coarse-grained crystals, mostly subhedral, with straight-to-lobate-to-serrated grain boundaries; surrounded by numerous fine-grained crystals which at places, impregnates the coarse carbonate crystals and form finger-like and island structures. Texture (1) is typical of plutonic carbonatites in extensional intraplate setting and texture (2) and (3) represents deformational changes as a result of high-strain and low-T conditions to high-T dynamic recrystallization, respectively. However, deformation has minor to none influence on the liquidus composition of dolomite-ankerite series carbonates. These carbonates, irrespective of texture, correspond compositionally with dolomite and ferroan dolomite, having Fe2+/Fe2++Mg=0.12–0.43. Concomitant increase in Fe and Mn and decreasing Mg at relatively restricted Ca content indicate magmatic origin and compositional evolutionary trend. Magnesite-siderite series carbonates are medium-grained (<300µm) subhedral to anhedral discrete crystals. These are magmatic in origin and are crystallized simultaneously with surrounding dolomite-ankerite series carbonates. Compositionally, these are ferroan magnesite and magnesian siderite with restricted Mg:Fe ratio of 0.96–1.12. The presence of magmatic magnesite-siderite series carbonates and the evolutionary trend displayed by dolomite-ankerite series carbonates attest for magmatic origin of the Newania carbonatites. Experimental work has demonstrated that dolomite and magnesite are stable up to the mantle depths of 80–110 kms and >110 kms, respectively. As the pressure approaches 32 kBar, the melts produced via. partial melting of phlogopite-bearing peridotite becomes more enriched in its magnesian content as the carbonate mineralogy changes from dolomite to magnesite. Such mantle-derived carbonatitic melts are inferred to be parent of the Newania carbonatites.
Assessing biotic response to anthropogenic forcing using mollusc assemblages from the Po-Adriatic System (Italy)
Authors: Scarponi Daniele , Rojas Alexis , Nawrot Rafał , Cheli Alessandro , Kowalewski Michał
Published: February 2023

Preserving adaptive capacities of coastal ecosystems in the Anthropocene requires an understanding of their natural variability prior to modern times. We quantified responses of nearshore molluscs assemblages to past environmental changes using 101 samples (~57300 specimens) retrieved from the subsurface Holocene succession and present-day seabed of the Po-Adriatic System (Italy). Present-day assemblages shifted in their faunal composition with respect to their mid-late Holocene counterparts. Major differences are observed in lower nearshore settings, where present-day samples show higher heterogeneity, reduced standardised richness, reduced relative abundance of Lentidium mediterraneum, and increased relative abundance of Varicorbula gibba, scavengers (genus Tritia), and deposit feeders (nuculid bivalves). A dominance of infaunal opportunistic species and shifts towards detritus-feeding and scavenging are often associated with disturbed benthic habitats. Our results suggest that the ongoing anthropogenic stressors (mainly bottom trawling and non-native species) are currently shifting benthic communities into novel states outside the range of natural variability archived in the fossil record.
Reverse Time Migration of offshore wide-angleseismic data: an efficient method to image deep crustal structures
Authors: Gonçalves Susana , Schnürle Philippe , Rabineau Marina , Afilhado Alexandra , Moulin Maryline
Published: February 2023

We image the Moho discontinuity and deeper crustal layers by applying the Reverse Time Migration (RTM) method to wide-angle seismic (WAS) data that were acquired along two different profiles in the NW and SE offshore Brazil. The application of this method is quite uncommon to ocean bottom seismometers (OBS) data due to the OBS wide spacing deployment and low folds. Also, we applied the method to each OBS without making any assumptions on the type of propagation generated inside the model. The long offset of the refractions obtained, allows us to image deeper crustal layers.Being able to obtain an image of these deeper layer is useful when MCS streamer data are not available or, even when they are, do not image the same depths.We analyze the effectiveness of the RTM method when applied to the reflectivity of the WAS data. We can image the structures by cross-correlating the forward and backward wavefields given by the acoustic seismic equation. This allows us to use each interface crossed by a ray as a source but also as a receiver.The velocity models used to perform RTM were previously obtained by applying a procedure of two-dimensional forward ray-tracing followed by a damped least-squares travel time inversion.The results obtained have an unexpected large contribution from the wavefield traveling as refractions within the earth. We obtain strong and continuous refractors for depths that correspond to the basement and the Moho discontinuity. As we move inland, the refractors that correspond to the Moho discontinuity disappear due to the move of this discontinuity to deeper depths. The obtained results are promising for a wide range of applications at a crustal scale seismic exploration, with wide-angle seismic data.Funding: This work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC) – UIDB/50019/2020- IDL
The last bits of glacial ice and permafrost as remains of the late Holocene Mediterranean glaciations. New discoveries from Mount Olympus periglacial zone
Authors: Styllas Michael , Onaca Alexandru , Ardelean Florina , Ardelean Adrian , Perșoiu Aurel , Pennis Christos
Published: February 2023

Despite the existence of numerous glaciers on the Mediterranean mountains during the Little Ice Age (LIA), many of these disappeared during the 20th century. However, periglacial conditions are sustained in the formerly glaciated alpine zones, preserving relicts of the late Holocene glacial record. The present climate of the Mediterranean mountains is hostile to glaciation and projected climate trends suggest that the Mediterranean cryosphere will be shrinking with immediate impacts on the water budget of the lowlands. Here we show preliminary results of an extensive fieldwork campaign that focuses on the Holocene reconstruction of the climate and alpine critical zone environmental conditions of Mount Olympus (2918 m) in Greece. A well-preserved sequence of late Holocene glacial moraines dating to ⁓2.5 and ⁓0.6 ka BP, respectively, suggest that the small cirque glaciers were geomorphologically active during the LIA, whereas 30 m deep glacial ice found in a perennial ice cave opens a new window of local and regional continuous climate reconstructions. The extensive snowfields of the mid-20th century have shrunk dramatically but have survived the warmest summers of the 21st century. Below these perennial snowfields a 15 m thick permafrost layer has been discovered during our campaign through 3 Electrical Resistivity Tomography (ERT) profiles, in a location where the mean annual air temperature (MAAT) of the last 10 years is above 0oC, but in agreement with permafrost occurrence in other mountains of the Southern Balkan peninsula. The base horizon of postglacial alpine soils overlying glacial till deposited in a glaciokarstic plateau below the summit, appears cryoturbated whereas the soils are characterized by translocation of clay from the upper to the lower horizon. These observations along with occasional early summer soil freeze and subsequent waterlogging, suggest that the periglacial activity on Mount Olympus continues in a rapidly warming Mediterranean environment. However, regional warming and anomalous early summer convective rainfall that has caused a dramatic reduction in the volume of the perennial ice cave deposits and the near extinction of the perennial snowfields (even after winters with very high snow accumulation) over the past 10 years also threatens this periglacial activity. Altogether these observations show the general decreasing trend of the Mediterranean cryosphere and periglacial activity, and they highlight immediate impacts on karstic aquifer water recharge and water availability in the piedmont and coastal zone of Mount Olympus, especially during the summer season when water demand is very high due to agricultural and touristic activities.
Modeling outdoor thermal comfort in waterfront urban fabric in a touristic city: Viña del Mar
Authors: Cárdenas-Jirón Luz , Matzarakis Andreas
Published: February 2023

Waterfront high-rise buildings are an urban feature found on the coast of many touristic cities in South America. One of the relevant effects is the modification of wind speed and wet balances coming from the Pacific Ocean flow to inland due to urban morphology. Solar radiation also changes owing to Sky View Factor SVF and slope. Understanding urban atmospheric and landscape dynamics would support strategies to offset adverse impacts of the built environment. Further, new bioclimatic conditions affect residents living behind high-rise buildings. The question is whether human comfort become worse or better for liveability in the streets and public spaces. The aim is to estimate outdoor thermal comfort in the urban fabric with two solar orientations: parallel and perpendicular to the predominant wind direction (SW-NE). Physiologically Equivalent Temperature PET quantified thermal stress to answer the question. Meteorological data are analyzed from a weather station situated in Viña del Mar for ten years. A city that holds the most visited Chilean beaches by international tourists. To this end, a complex urban environment applied the RAYMAN model. Results point out recommendations for urban design and planning. 
Variscan and post-Variscan processes in the Central-Sudetic Ophiolite: records from carbonate and silicate rocks.
Authors: Cieślik Błażej , Pietranik Anna , Kierczak Jakub
Published: February 2023

The northeastern part of Bohemian Massif is composed of various lithotectonic domains interpreted as microplates, sedimentary basins, and fragments of ancient oceanic lithosphere, which have been amalgamated during the Late Devonian multistage collision. Fragments of the Variscan Central-Sudetic Ophiolite (CSO) preserve information on the nature of the mantle at the onset of Variscan orogeny. They are mainly composed of ultramafic-mafic rocks (UMR) dated at 400 Ma, but these are not the only components. Other lithologies include (a) carbonate veins crosscutting the UMR, (b) dolomite-rich domains associated with clinopyroxenites, and (c) silicic dyke of diorite composition also crosscutting the UMR. The origin of these lithologies may be contemporaneous with UMR or later (Variscan or Cenozoic) and obtaining the ages is the first step to understanding which events they record. Zircons from the diorite yield a concordia age of 378.0 ± 5.0 Ma (SHRIMP) consistent with the diorite representing an early Variscan magmatic episode. The obtained age of the intrusion suggests an affinity with a located nearby outcrop of ultrapotassic syenites (from 378.2 ± 2.4 to 354.7 ± 4.3 Ma). A striking relationship between the two rocks is evident; if certain elements are strongly enriched in one rock they are equally impoverished in the other. Such unusual chemical fractionation can be achieved during the formation of alkaline and carbonatite melts. Also, dolomite domains recently found in clinopyroxenites or puzzling anhydrite inclusions in Ca-amphiboles may support this hypothesis suggesting an enriched mantle as a common source of dioritic, syenitic, and dolomitic lithologies. On the other hand, carbonate veins record another episode. Recently, the U-Pb radiometric dating of calcite sampled from one of the CSO massifs yielded an isochrone age of 15.4 ± 19.7 Ma that generally suits Paleogene and Neogene tropical weathering events, moreover, some parts of CSO contain abundant carbonates mineralization accompanied by plenty of quartz zonal clusters. The co-occurrence of these phases may suggest hydrothermal origin and becomes a foothold for further studies on the carbonation of obducted oceanic lithosphere.Altogether, it is important to bear in mind CSO’s 400 Ma-long evolution. It seems that Central-Sudetic Ophiolite and associated younger lithologies still have more to tell us about the orogenic and post-orogenic history of the northeastern Bohemian Massif.Funding: The research is funded by NCN grant PRELUDIUM no. UMO-2022/45/N/ST10/00879 awarded to Błażej Cieślik.
Hadley Cell Variability during the Last Millenium and response to volcanism in the PMIP4/CMIP6 models
Authors: Silva Paulo , Wainer Ilana , Khodri Myriam
Published: February 2023

In the Tropics, the Hadley Cell plays a key role in controlling precipitation patterns, since it is related to the position of the ITCZ, which is also a main component of the South America Monsoon System (SAMS). Several studies have documented a poleward expansion of the Hadley Cell over the historical period and a shift in the position of its subsiding branches and the expansion of the subtropical dry zones. This widening has largely been attributed to anthropogenic forcing, such as greenhouse gases (GHG) and stratospheric ozone depletion. However, prior to the industrial period, the extent of the Hadley Cell is dominated by internal variability and the radiative effects of volcanic eruptions. Understanding this natural variability is key to better predict the possible combined effects with anthropogenic external forcing. Thus, in this study we to investigate the variability of the Hadley Cell during the Last Millennium and its response to volcanic eruptions. We rely on the simulations of the Last Millennium provided by the Paleoclimate Modeling Intercomparison Project (PMIP4) contribution to the Climate Model Intercomparison Project phase 6 (CMIP6).
5-yr long records of aerosol and surface snow chemical composition at Dome C (High Antarctic Plateau)
Authors: Traversi Rita , Becagli Silvia , Caiazzo Laura , Cristofanelli Paolo , Nardin Raffaello , Putero Davide , Severi Mirko
Published: February 2023

The study of aerosol chemical composition in the Antarctic plateau can provide basic information on the main natural (and also anthropogenic) inputs, atmospheric reactivity, and long-range transport processes of the aerosol components. Moreover, chemical and physical processes occurring at the atmosphere-snow interface are yet not fully understood and work is needed to assess the impact of atmospheric chemistry on snow composition and to better interpret ice core records retrieved at those sites.At this purpose, simultaneous aerosol and surface snow samplings were set up and run at Dome C station (75° 06’ S; 123° 20’ E, 3233 m a.s.l) all year-round since 2004/05 and are still ongoing through various PNRA Projects, particularly LTCPAA (2016-2020) and STEAR (2020-2023).Aerosol and snow samples were analysed for main and trace ion markers, aiming to better constrain extent and timing of the main natural sources (sea salt, marine biogenic, mineral dust) and to detect the possible contribution of anthropic inputs (biomass burning, wildfires, local contamination). In addition, such a study might help in improving our knowledge of transport processes (free troposphere, stratosphere-troposphere exchange) and atmospheric reaction processes (such as neutralization, chemical fractionation).A comparison with ozone measurements, carried out continuously over the same period, is also attempted, to better address the atmospheric processes involving the atmosphere-snow exchanges of N-cycle species and atmosphere oxidative properties.
Characterising faults in geothermal fields using surface waves: a numerical study
Authors: Kennedy Heather , Löer Katrin , Gilligan Amy , Finger Claudia
Published: February 2023

Subsurface characterisation of geothermal fields is important for the expansion of geothermal energy as a low-carbon resource. Faults and fractures provide secondary permeability, thus, their characteristics are crucial parameters in deep geothermal fields. Analysis of ambient seismic noise provides a relatively cheap and widely accessible method for constraining faults and fractures in geothermal settings. Three-component (3C) beamforming is an array-based method that extracts the polarizations, azimuths, and phase velocities of coherent waves as a function of frequency from ambient seismic noise, offering a comprehensive understanding of the seismic wavefield. 3C beamforming can be used to determine surface wave velocities as a function of depth and the direction of propagation of waves. It is assumed that anisotropic velocities relate to the presence of faults, giving an indication of the maximum depth of the permeability essential for fluid circulation and heat flow throughout a geothermal field. Previous results suggests that some structures have a stronger effect on surface wave velocities than others. Numerical models are essential to study these relationships in more detail. Here we present a numerical simulation of wave propagation through a model of the subsurface, with anisotropy depicted as faults. This is employed by a rotated staggered grid (RSG) finite-difference (FD) scheme. We model a homogeneous half-space with a fault-like structure (40 m width), changing fault parameters, such as depth, width, velocities and internal conditions of the fault (“fill”). We generate surface waves from a single source as well as multiple sources emulating an ambient noise wavefield. We then use 3C beamforming on the synthetic data to characterise the modelled wavefield and observe the types of waves present. The polarisation and beam power of the synthetic data denote the composition of the synthetic wavefield and what percentage are retro- and prograde Rayleigh waves and Love waves. To investigate the strength of anisotropy introduced by a single fault we propagate surface waves across the fault in different directions, estimating velocities from array recordings using the beamformer. We are further able to assess the sensitivity of Rayleigh waves towards anisotropy at depth by considering Rayleigh waves at different frequencies sampling different depths.
Realistic Wake Simulation using the WRF-SADLES System
Authors: Bui Hai , Bakhoday-Paskyabi Mostafa
Published: February 2023

Simulating wind turbine wakes with high accuracy is crucial for understanding their effects on nearby flow patterns and optimizing the design and operation of wind farms. However, current Large Eddy simulation (LES) models for this purpose often rely on highly idealized boundary layer conditions, which may not capture all relevant realistic processes. In this study, we present the development and application of a Simple Actuator Disc model for Large Eddy Simulation (SADLES) for simulating wakes in realistic conditions. SADLES was developed to utilize traditional thrust and power curves provided by turbine manufacturers, while also achieving an intermediate resolution of a few dozen meters to strike a balance between fidelity and computational cost. SADLES has been integrated into the Weather Research and Forecast (WRF) model, resulting in the WRF-SADLES system. Using this system, atmospheric conditions from ERA5 data were downscaled to a wake-enable scale of 40 m using a system of 5 nested domains. Selected transition events were simulated and the results were validated using real observations from the FINO1 meteorological mast and LiDAR data. Our WRF-SADLES approach represents a promising advancement in the simulation of wind turbine wakes and their impacts on surrounding flow fields.
Analysis of infrasound and seismic signals recorded from repetitive explosion sources at near-regional distance
Authors: Ghica Daniela , Ionescu Constantin
Published: February 2023

Simultaneous observations of infrasonic and seismic signals recorded with the Romanian seismo-acoustic arrays (BURAR, BURARI and IPLOR) are used to forensic tracking the repetitive explosion sources generated by the bombing and shelling taking place in Ukraine since 24 February 2022. Seismo-acoustic signature (signal shape and amplitude, frequency content, energy spectrum) analyzed are characterized by impulsive energetic signals. Events reported in the bulletins provided by IDC/CTBTO are used as reference for associating infrasound and seismic detections of the Romanian arrays. Infrasound signals observed with BURAR seismic array are added to better characterize the type of events in this region. Seismo-acoustic data are analyzed by using processing capabilities of the DTK-GPMCC and DTK-DIVA software embedded in NDC-in-a-Box package.Infrasonic detections are strongly influenced both by seasonally dependent stratospheric winds and local turbulence-induced pressure fluctuations, i.e., level of wind-generated background noise increases with station altitude. Directions of IPLOR and BURARI infrasonic detections are estimated and the locations are obtained by cross-bearing the derived back azimuths. Deviating effects of zonal cross winds along the propagation path through the atmosphere affect the observed back azimuths: rays which arrive at BURARI are deflected towards the East with approx. 5o, whilst at IPLOR, the azimuthal deviation is negligible (below 1o).The propagation path of infrasonic signals is analyzed by applying infraGA 2D ray tracer through NRL-G2S atmospheric model. Stratospheric and thermospheric infrasound phases are identified to be observed at BURARI and IPLOR stations.lease insert your abstract HTML here.
Best Practices for Fortran-Python Bridges to Integrate Neural Networks in Earth System Models
Authors: Arnold Caroline , Sharma Shivani , Weigel Tobias , Greenberg David
Published: February 2023

In recent years, machine learning (ML) based parameterizations have become increasingly common in Earth System Models (ESM). Sub-grid scale physical processes that would be computationally too expensive, e.g., atmospheric chemistry and cloud microphysics, can be emulated by ML algorithms such as neural networks.Neural networks are trained first on simulations of the sub-grid scale process that is to be emulated. They are then used in so-called inference mode to make predictions during the ESM run, replacing the original parameterization. Training usually requires GPUs, while inference may be done on CPU architectures.At first, neural networks are evaluated offline, i.e., independently of the ESM on appropriate datasets. However, their performance can ultimately only be evaluated in an online setting, where the ML algorithm is coupled to the ESM, including nonlinear interactions.We want to shorten the time spent in neural network development and offline testing and move quickly to online evaluation of ML components in our ESM of choice, ICON (Icosahedral Nonhydrostatic Weather and Climate Model). Since ICON is written in Fortran, and modern ML algorithms are developed in the Python ecosystem, this requires efficient bridges between the two programming languages. The Fortran-Python bridge must be flexible to allow for iterative development of the neural network. Changes to the ESM codebase should be as few as possible, and the runtime overhead should not limit development.In our contribution we explore three strategies to call the neural network inference from within Fortran using (i) embedded Python code compiled in a dynamic library, (ii) pipes, and (iii) MPI using the ICON coupler YAC. We provide quantitative benchmarks for the proposed Fortran-Python bridges and assess their overall suitability in a qualitative way to derive best practices. The Fortran-Python bridge enables scientists and developers to evaluate ML components in an online setting, and can be extended to other parameterizations and ESMs.
Dynamic and thermodynamic effects driving anomalous precipitation over Amazon
Authors: Vasconcellos Fernanda Cerqueira , Li Laurent
Published: February 2023

Anomalous rainfall produces droughts and floods over the Amazon region, enhancing risks of forest fires, heatwaves and inundations, which affects the regional fauna, flora, and socioeconomic activities. In this study, the driest and wettest years of the Northern and Southern Amazon are investigated by analyzing the regional moisture and moist static energy budget. For the Northern and Southern Amazon, the dynamic effect, related to vertical movement changes, was the primary cause for the precipitation anomalies. The thermodynamic effect connected with moisture changes also contributed to the Northern Amazon precipitation anomalies. The anomalous vertical motion in the Northern Amazon was mainly caused by the horizontal advection of anomalous moist enthalpy through climatological wind, which alters the moist static energy in the region. Thus, a vertical movement is produced to compensate the energy changes, leading to changes in precipitation. Nonlinear terms and the horizontal advection of climatological moist enthalpy by the anomalous wind constrained the vertical motion in the driest years over Southern Amazon. For the wettest years over Southern Amazon, the anomalous ascending movement had contributions from all moist static equation terms, except the vertical advection of anomalous moist static energy by climatological wind, which had an opposite effect. The latent heat was the main contributor to anomalous moist enthalpy influencing the vertical movement. Further investigations indicated that the tropical Atlantic and Pacific SST anomalies could influence the vertical anomalies. In conclusion, although the dynamic effect (changes in the vertical motion) was the main driver for precipitation anomalies, the thermodynamic contribution related to latent heat anomalies is significant, mainly for Northern Amazon.
Extending the NIR auroral map of Uranus through the 21st century
Authors: Thomas Emma , Stallard Tom , Melin Henrik , Moore Luke , Chowdhury Mohammad , Wang Ruoyan , Knowles Katie
Published: February 2023

Over 30 years of near infrared (NIR) observations at Uranus starting in 1992 with Trafton, et al., 1993, it is only in the last 5 years we have had any significant breakthroughs in mapping of NIR auroral morphology. The first confirmed auroral observations by Thomas, et al., (in review) and a tentative auroral detection by Melin, et al., (2019) have now shown that NIR aurora detections at Uranus are possible from ground-based observations. Thomas, et al. concluded that sections of the NIR northern aurora were observed for the first time and even outlined the first NIR auroral arcs, however due to observational limitations and the loss of Uranian Longitude System (ULS) a complete map could not be accomplished. With the ULS southern hemisphere now predominately facing the Earth (since the planet’s equinox of 2007), we are poised to reveal the auroral morphology of the southern aurora with detail never seen before. Success in this aim will yield the first insights into ionospheric magnetospheric interactions at Uranus when exposed to dynamic changes in the planet's magnetic field orientation to the solar wind and the first NIR maps to guide auroral expectations at sub-Neptune exoplanets.In this study, we have taken ground-based observations of H3+ emissions from Uranus’s Equinox to 2022 and construct the first NIR composite map of the geographical equator and southern hemisphere to identify if similar auroral features appear as was observed in 2006, and to extend the NIR auroral mapping across Uranus.
Low Latitude Ionosphere Observed by the Sanya Incoherent Scatter Radar
Authors: Yue Xinan , Wan Weixing , Ning Baiqi , Ding Feng , Wang Junyi , Cai Yihui , Zhang Ning , Li Mingyuan , Wang Yonghui , Zhou Xu , Wang Zhongqiu
Published: February 2023

Sanya (18.3°N, 109.6°E) Incoherent Scatter Radar (SYISR) is a newly built ISR in low latitude China. The unique features of SYISR include a single-channel directly connected T/R unit and antenna, a radar array monitoring and calibration network, environmental adaptability design and open architecture. Since 2022, we have run SYISR almost continuously. In this presentation, at first we will generally describe the technical details of SYISR. Then we will show the ionospheric observations made by SYISR, including equatorial bubble, ion line and plasma line results, and derivation of low latitude neutral wind and ionospheric electric field. At the end, we will introduce the development status of the SYISR Tristatic System.
Northward Prpogating BSISO over South Asia: connection between moisture advection and vortex tilting
Authors: Ghatak Sambrita , Sukhatme Jai
Published: February 2023

The mechanism behind the northward propagation of the Boreal Summer Intraseasonal Oscillation (BSISO) over South Asia is still elusive, though many theories have been proposed to explain it. In this study, column- integrated moisture budget and vorticity budget analyses are used on NCEP-NCAR1 and ERA5 reanalyses data to understand the dominant propagation mechanism. While traditional theories have focused on the importance of monsoon winds' vertical easterly shear (via vortex tilting) in preconditioning the atmosphere north of the convection centre by inducing a barotropic vorticity anomaly that supports boundary layer convergence, recent work based on the 'moisture mode' framework suggests that moistening ahead of convection by horizontal moisture advection is necessary for the convection to move northward. In this study, we show that both vortex tilting and moisture advection are essential for northward propagation. The moisture budget analysis shows that when the organized convection first appears over the Indian Ocean, easterlies associated with the Rossby wave response to the convection act on the climatological moisture distribution. This moisture gradient is large along the anomalous wind direction over the Arabian Sea and leads to rapid moistening in the southern Arabian Sea region, while over the Bay of Bengal, this process is not as effective as the moisture gradient is not aligned with the anomalous wind direction over the whole Bay. Thus, the characteristic northwest-southeast oriented convection observed in the BSISO over South Asia comes into being. Hence, a tilted belt of strong convection is present behind the dry anomalies associated with subsidence, and as the convection is associated with strong ascent, the vortex tilting term also acquires a tilted structure aligned with the meridional gradient in vertical velocity. The vorticity budget clearly shows tiling is the dominant term that matches the tendency and leads to the vorticity anomalies, and the dominant term in tilting is the term associated with the meridional gradient of anomalous vertical velocity and vertical shear of zonal mean wind. The pronounced northward movement of vorticity anomalies over the Arabian Sea (more than over the Bay) further increases the tilt of the gyre associated with the convection, thus, winds over the northern Indian landmass, particularly above 20N become south-easterly. These anomalous winds tap into the north-westward moisture gradient that is present over much of the northern Indian landmass and helps move the convection further north over the northern part of the subcontinent. Thus, these two processes together pull the convection band northward over the South Asian monsoon region from the Indian Ocean and generate the NW-SE-oriented structure of the BSISO. We also show the vertical structures of the budget terms, which reveals that the moisture advection is primarily important in the middle to lower free troposphere. 
Marine Heatwaves in the Arctic Ocean: drivers, feedback mechanisms and interactions with sea ice
Authors: Richaud Benjamin , Oliver Eric C.J. , Hu Xianmin , Darmaraki Sofia , Fennel Katja
Published: February 2023

Arctic regions are warming at a rate faster than the global average. Superimposed on this trend, marine heatwaves and other extreme events are becoming more frequent and intense. Simultaneously the sea ice phenology with which these events interact is also changing. While sea ice can absorb atmospheric heat by melting and therefore acts as a heat buffer for the ocean, meltwater-induced stratification and albedo changes can provoke positive feedbacks on the heat content of the upper ocean. Disentangling those effects is key to better understanding and predicting the present and future state of the Arctic Ocean, including how it responds to forcing by extreme events. Using a three-dimensional regional ice-ocean coupled numerical model, we calculate a two-layer heat budget for the surface mixed layer of the Arctic Ocean, using a novel approach for the treatment of residuals. We present a statistical overview of the dominant drivers of marine heatwaves at the regional scale as well as more in-depth analyses of specific events in key regions of interest. The characteristics of marine heatwaves under different sea ice conditions is also considered, to identify anomalous ice-ocean interactions. Finally, potential feedback mechanisms are investigated to verify their existence and quantify their importance.
Imaging of seismic sources by surface-wave time-reversal: long-period earthquakes
Authors: Sharma Dhakal Apsara , Boschi Lapo , Cesca Simone
Published: February 2023

The study of long-period events in a volcanic setting is of fundamental importance to better understand the physics of volcanic plumbing systems. We locate such events using a source-imaging method developed by our team, and successfully applied, e.g., to the great Sumatra earthquake (Dhakal et al. 2022). Our approach combines seismic time reversal with a surface-wave ray tracing algorithm based on generalized spherical-harmonic parameterization of surface-wave phase velocity, and accounting for azimuthal anisotropy. We present a new application, to recordings of a suite of Mayotte events that Cesca et al. (2020) have already studied and interpreted in terms of the drainage of a magma reservoir.We first conduct synthetic tests to quantify the resolving power of our method, given the available data coverage for the events of interest. We then use low-frequency Rayleigh wave signals recorded by different stations, reverse them in time and back propagate them through a surface-wave phase-velocity model. The time-reversed wave field has a prominent maximum at the spatial location(s) and time(s) where and when the recorded signal had been generated. From the time- and space-distribution of such maximum, we can make inferences on the nature of the source. Results so obtained are compared with those determined by Cesca et al. (2020) via moment tensor inversion and found to be in good agreement. We infer that our methodology is applicable to volcanic settings, possibly providing new insights into the nature of long-period seismic sources related to volcanic activity. The precise location of such events can provide better constraints on the depth interpretations and the extent of the seismic source.
Stratospheric aerosol size decrease after volcanic eruptions
Authors: Wrana Felix , Niemeier Ulrike , Wallis Sandra , von Savigny Christian
Published: February 2023

The evolution of the size distribution of stratospheric aerosols after volcanic eruptions is still not understood very well, due to the temporal sparsity of in situ measurements, the low spatial coverage by ground based observations and the difficulties to derive aerosol size information from satellite measurements. To contribute to this ongoing research, we show data from our aerosol size retrieval using SAGE III/ISS solar occultation measurements. Using a three wavelength extinction approach the parameters of assumed to be monomodal lognormal particle size distributions are retrieved.Surprisingly we find that some volcanic eruptions can lead to a decrease in average stratospheric aerosol size, in this case the eruptions of Ambae in 2018, Ulawun in 2019 and La Soufrière in 2021, while other eruptions have a more expected increasing effect on the average particle size, like the 2019 Raikoke eruption. We show how different parameters like the median radius, the absolute mode width and the number density evolve after the mentioned eruptions.Additionally, as a part of our ongoing research to understand the underlying mechanisms controlling the observed aerosol size reduction, we show simulations of the aforementioned volcanic eruptions using the aerosol-climate model MAECHAM5-HAM. Although the initial conditions in the model simulations are different from observations due to missing smaller emissions in the time before the eruptions, a good agreement in the perturbations of the extinction coefficient was achieved.
Nine years of temporal gravity changes observed by the Swarm satellites
Authors: de Teixeira da Encarnacao Joao , Daniel Arnold , Bezdek Ales , Dahle Christoph , Guo Junyi , van den IJssel Jose , Jaeggi Adrian , Klokocnik Jaroslav , Krauss Sandro , Mayer-Guerr Torsten , Meyer Ulrich , Sebera Josef , Shum Ck , Visser Pieter , Zhang Yu
Published: February 2023

Although a satellite mission to observe Earth’s magnetic field, the Swarm satellites also collect GPS data with sufficient accuracy to observe Earth’s gravity field with a spatial resolution of roughly 1500 km. These monthly models are available from 2014 to the present and do not rely on any other source of gravimetric data nor any a priori information in, for example, the form of temporal and spatial correlations. This time series covers the gap between the GRACE and GRACE-FO missions, as well as any other short gaps in their time series. Given the healthy state of the Swarm satellites, it is also likely that it will provide gravimetric information during possible gaps in the GRACE-FO data, and future dedicated gravimetric satellite missions.We are a consortium of international research institutes, composed of the Astronomical Institute of the University of Bern, the Astronomical Institute of the Czech Academy of Sciences, the Delft University of Technology, the Institute of Geodesy of the Graz University of Technology, and the School of Earth Sciences of the Ohio State University. These activities are supported by the European Space Agency and the International Combination Service for Time-variable Gravity Fields (COST-G). We publish the models every 3 months at ESA’s Swarm Data Accessserver (https://swarm-diss.eo.esa.int) as well at the International Centre for Global Earth Models (http://icgem.gfz-potsdam.de/series/02_COST-G/Swarm). Each institute exploits different gravity inversion strategies, thus producing independent solutions, which are combined at the solution level using weights derived with Variance Component Estimation. In this way, we ensure the published models are not biased towards particular strategies or assumptions.We illustrate the geophysical signal captured by Swarm’s GPS receivers over large hydrological basins, the errors represented by the variability of the models over the oceans and the agreement with GRACE and GRACE-FO. All analyses span the GRACE/GRACE-FO gap, to illustrate the importance of the Swarm satellites to bridge the absence of low-low satellite-to-satellite tracking data.
A novel way of identifying agricultural water drainage systems and their impact on catchment hydrology
Authors: Yimer Estifanos Addisu , Riakhi Fatima-Ezzahra , Yadollahi Shahla , Weerasinghe Imeshi , Wirion Charlotte , T. Bailey Ryan , Nossent Jiri , van Griensven Ann
Published: February 2023

Water drained from agricultural lands is getting more attention as its valuable water is lost from groundwater storage. The historical location of buried agricultural water drainage systems is not known very well. Hence, first, finding the location of those infrastructures is critical. Several methods have been applied in the past, including decision tree classification (DTC), remote sensing based, using radar, etc. However, all the methods neglect the primary cause of the drain application, which is groundwater. Hence, a novel approach is introduced that considers groundwater in the identification procedure. We used two case studies for drain identification, one from Ontario, Canada, and another from Belgium. Furthermore, a physically based and fully distributed modeling approach (SWAT+gwflow) is conducted to investigate the impact of these drainage systems in the catchment hydrology of the Kleine Nete watershed, Belgium.The result of the drainage system identification has indicated the pitfalls of the already existing methods where accuracy as low as 17% was recorded. On the other hand, the additional filtering based on groundwater head enables us to find an additional 19.4 km2 area. Therefore, the use of groundwater level as an additional filtering technique is vital for increasing the accuracy of tile drain/ditch network identification. Next, drains have been shown to affect hydrology, where a 15% decrease in groundwater evapotranspiration, a 50% reduction in groundwater saturation excess flow, and a 39% decline in groundwater discharge to streams are observed.