bluuebunny/crossref_metadata_2025 huggingface dataset:
Rigidity dependence of cosmic ray diurnal anisotropy using 22 years of GRAPES-3 muon telescope data
Authors: Zuberi Meeran ,   The GRAPES-3 Collaboration
Published: February 2023

The GRAPES-3 muon telescope (G3MT) has been recording high statistics of muons at a rate of ~50000 per second for the past two decades allowing us to probe the tiny variations in the muon flux caused by solar phenomena. The directional capabilities of G3MT enable us to look into 169 independent directions with a large median rigidity ranging from 64 to 141 GV. We have examined the 22 years (2000-2021) of G3MT data using the Fourier series technique to obtain the daily SDA amplitude and phase. The measured SDA amplitude and phase show a strong rigidity dependence. We found that the phase dominantly has the 22-year variation controlled by the drift effect due to solar polar magnetic field reversal, regardless of their rigidity. However, the higher rigidity bin phase variation shows an additional component of the 11 years controlled by the diffusion. The details of this work will be discussed during the talk.
Assessing Chamelea gallina biomineralization dynamics in the Holocene of the Northern Adriatic (Italy)
Authors: Cheli Alessandro , Mancuso Arianna , Falini Giuseppe , Goffredo Stefano , Scarponi Daniele
Published: February 2023

This study investigates the variation of skeletal and growth parameters of the bivalve Chamelea gallina in the Holocene of the Po-Adriatic System (Italy). C. gallina is a valuable economic species in the Mediterranean Sea, expected to be impacted by numerous anthropogenic stressors that threaten the biological and economic sustainability of its fishery. Here, skeletal parameters (micro-density and apparent porosity) and growth parameters (bulk density, linear extension and net calcification rates) of C. gallina shells were investigated in four shoreface-related C. gallina shell-rich deposits. Two from present-day Adriatic shoreface seabeds and two from comparable settings of the middle Holocene, when regional sea temperatures were higher than today. In each horizon, 30 right valves of different sizes were measured and aged using three independent methods (shell surface growth rings, shell internal bands and 18O/16O ratio) to determine the Von Bertalanffy growth functions. Which, in turn, allowed us to estimate targeted parameters for each assemblage investigated. Differences in the skeletal and growth properties of C. gallina shells were also investigated in relation to animal sexual maturity. C. gallina appears to be sensitive to changes in environmental conditions, showing macro-scale variations in bulk and micro-density. Shells from the middle Holocene presented a denser exoskeleton than modern ones, probably because of different mineralization rates mainly driven by temperature. Nevertheless, linear extension and net calcification rates showed no differences between past and modern assemblages, also when immature and mature individuals were analyzed separately. C. gallina biomineralization dynamics evaluated on timescales well beyond ecological monitoring offer insights into its adaptive capacities to face near-future global warming.
Belowground growth responses of mature Picea sitchensis forest stand at different levels of soil warming
Authors: Sigurðsson Páll , Ostonen Ivika , Oddsdóttir Edda S. , Sigurdsson Bjarni D.
Published: February 2023

Climate warming is predicted to be more pronounced in higher latitudes. As climate warms, it results in higher surface temperatures, subsequently raising the soil temperature, thus affecting soil processes, such as root growth and belowground C input. To improve our predictions of the response of boreal forests to climate change, it is important to better understand the effects the warming has on fine root production and mortality and how belowground NPP changes as compared to aboveground NPP. The ForHot research site in Iceland is a natural soil warming experiment, created in May 2008 by a major earthquake, after which the geothermal bedrock channels became warm in previously cold areas. In this study we use an experimental site with a stand of 50 year old Sitka spruce (Picea sitchensis), growing in soils, with a warming gradient from 0 to +6°C between 2008 and 2018.For this study we used soil coring to assess fine root biomass (FRB), and minirhizotron technique to assess the fine root longevity. By combining these data, we were able to estimate the absolute values of fine root turnover, and thus the belowground litter input as well as belowground NPP along the soil warming gradient. By assessing the aboveground litter input with litter traps, we were as well able to estimate the ratio of above- and belowground litter inputs into the soil along the warming gradient. Our results showed a decrease in the fine root biomass with higher soil temperature, higher fine root turnover rate, and a higher ratio of above/belowground litter input.
Simulating oceanic mesoscale eddy dynamics: A comparison of novel parameterizations and energy diagnostics and their impact on the global ocean circulation
Authors: Juricke Stephan , Danilov Sergey , Oliver Marcel , Kutsenko Anton , Bellinghausen Kai
Published: February 2023

In this study, we present a variety of parameterizations for simulating ocean eddy dynamics including novel viscous and kinetic energy backscatter closures. Their effect is analyzed using new diagnostics that allow for application on unstructured meshes.Ocean mesoscale eddy dynamics play a crucial role for large-scale ocean currents as well as for the variability in the ocean and climate. The interactions between eddies and the mean flow affect strength, position and variations of ocean currents. Mesoscale eddies have a substantial impact on oceanic heat transport and the coupling between the atmosphere and ocean. However, at so-called eddy-permitting model resolutions around ¼°, eddy kinetic energy and variability is often substantially underestimated due to excessive dissipation of energy. Despite ever-increasing model resolutions, eddy-permitting simulations will still be used in uncoupled and coupled climate and Earth system simulations for years to come.To improve the presentation of eddy dynamics in such resolution regimes, we present and systematically compare a set of viscous and kinetic energy backscatter parameterization with different complexity. These schemes are implemented in the unstructured grid, finite volume ocean model FESOM2 and tested in both idealized channel and global ocean simulations. We show that kinetic energy backscatter and adjusted viscosity parameterizations can alleviate some of the substantial eddy related biases, for example biases in sea surface height variability, mean currents and in water mass properties. We then further analyze the effect of these schemes on energy and dissipation spectra using new diagnostics that can be extended to the unstructured grid used by FESOM2. The rigorous intercomparison allows to make informed decisions on which schemes are the most suitable for a given application, considering the complexity of the schemes, their computational costs, their adaptability to various model resolutions and any simulation improvements related to a specific scheme. We will show that novel viscous and kinetic energy backscatter schemes outperform previously used, classical viscous closures. Furthermore, when compared to higher resolution simulations, they are computationally less expensive but achieve similar results.
A multidisciplinary approach for 3D modelling of the Serre and Cittanova Faults, the responsible of the 1783 seismic sequence in Southern Calabria, Italy.
Authors: Giuffrida Salvatore , Brighenti Fabio , Carnemolla Francesco , Gambino Salvatore , De Guidi Giorgio , Barreca Giovanni , Cannavò Flavio , Scarfì Luciano , Monaco Carmelo
Published: February 2023

Since the Late Pliocene - Early Pleistocene, the Calabrian Arc (southern Italy) is affected by extensional and transcurrent tectonic superimposed on the previous collisional context. Various seismogenic sources have been proposed over time to explain such a complex structural framework, but the topic is still matter of debate. In this work we apply a multidisciplinary approach, concerning Geology, Geomorphology, Seismology and Geodesy, to develop a reliable 3D model of the Cittanova and Serre faults. These faults are considered the causative faults for the 1783 seismic sequence (M 6.5-7) as proposed by Jacques et alii (2001). We used CROP data to investigate the crustal architecture of the area and to constrain the geometry at depth of the major structures. through two schematic geological sections orthogonal to these two faults. The shallow geometric patterns of the Cittanova and Serre faults, were verified trough geological, geomorphological and structural field data. Earthquakes hypocentres were analysed and relocated in order to recognize possible cluster alignments useful to constrain the faults geometry at depth. The high-density level of crustal seismicity attests that this domain is seismically active, between 0 km and 23 km and it concentrates along the main faults. To compute the strain and velocity field of the area (time span of the last 20 years) we measured the IGM95  (Instituto Geografico Militare) benchmarks and processed several GNSS permanent stations belonging to the RING Network (http://ring.gm.ingv.it) and TopNETlive Italy Network (https://rtk.topnetlive.com/italy/networks/topnet-live-italy) using GipsyX 1.5 Strain inversion (performed through grid_strain 2D software) allowed us to define a predominant WNW-ESE extensional deformation, in agreement with previous studies). Combining all previous data, we built for the first time a reliable 3D model of the Cittanova and Serre fault planes, that are consistent with:  i) fault magnitude/size empirical relations (Magnitude vs rupture Area, Magnitude vs fault length; ii) geological and geomorphological field observation (fault attitude and kinematic), iii) seismological and geodetic data. Results show that our model is compatible with the seismogenic sources of the 1783 seismic sequence.
Physiography improvements in numerical weather prediction digital twin engines
Authors: Rieutord Thomas , Bessardon Geoffrey , Gleeson Emily
Published: February 2023

The next generation of numerical weather prediction model (so-called digital twin engines) will reach hectometric scale, for which the existing physiography databases are insufficient. Our work leverages machine learning and open-access data to produce a more accurate and higher resolution physiography database. One component to improve is the land cover map. The reference data gathers multiple high-resolution thematic maps thanks to an agreement-based decision tree. The input data are taken from the Sentinel-2 satellite. Then, the land cover map generation is made with image segmentation. This work implements and compares several algorithms of different families to study their suitability to the land cover classification problem. The sensitivity to the data quality will also be studied. Compared to existing work, this work is innovative in the reference map construction (both leveraging existing maps and fit for end-user purpose) and the diversity of algorithms to produce our land cover map comparison.
The MoonLIGHT Pointing Actuator (MPAc) project
Authors: Rubino Laura , Remujo Castro Alejandro , Denni Ubaldo , Muccino Marco , Salvatori Lorenzo , Tibuzzi Mattia , Petrassi Matteo , Montanari Michele , Traini Marco , Filomena Luciana , Mauro Lorenza , Porcelli Luca , Dell'Agnello Simone
Published: February 2023

Laser Ranging is a technique used to perform accurate precision distance measurements between a laser ground station and an optical target, a Cube Corner Retroreflector (CCR). Since 1969 it is possible to realize Lunar Laser Ranging (LLR) measurements thanks to Apollo and Luna missions that placed some arrays of CCRs on the lunar surface. LLR outputs include accurate tests of General Relativity, information of the composition of the Moon, its ephemerides and its internal structure or geocentric positions and motions of ground stations: research uniquely enabled by the Moon.
Despite laser ground stations have significantly improved during the years, the current limitation of the lunar optical target is due to lunar librations. In order to achieve more precise LLR measurements, MoonLIGHT project is designed by SCF_Lab joined UMD. The aim of the project is designing a next-generation of retroreflectors, prototyping, manufacturing and qualify them for the Moon’s environment. Moving from a multi small CCRs array to a single large 100 mm CCR, called MoonLIGHT, unaffected by the lunar librations.
The field of view of each CCR is limited: the retroreflector needs to be pointed precisely to the ground station. The Apollo CCR arrays were manually arranged by the astronauts. In 2018 INFN proposed to ESA the MoonLIGHT Pointing Actuators (MPAc) project, able to perform unmanned pointing operation of MoonLIGHT. In 2019 ESA chose MPAc among 135 eligible scientific project proposals. In 2021 ESA agreed with NASA to launch MPAc to the Reiner Gamma region of the Moon, with a Commercial Lunar Payload Services (CLPS), which is part of the Artemis program. The lander on which MPAc will be integrated is designed by Intuitive Machines (IM). The launch expected date is in April 2024.
MPAc must be able to perform two continuous perpendicular rotations to accurately point the frontal face of the CCR towards the Earth. The device is continuously evolving to ensure the success of the mission, that will take place in Ultra High Vacuum space conditions, in a wide operating temperature range. Terrestrial prototypes, with all the characteristics of the final structure, have been developed for the study of mechanical and electronics components. Qualification tests for space are being planned as the components for the Proto Flight Model (PFM) arrived to the LNF. Payload delivery is scheduled for August 2023.
MPAc will contribute to attain lunar orbit range accuracy below few mm. This will improve, in turn, the precision of the Parametrized Post-Newtonian (PPN) parameters and put more stringent constraints on departures from GR predictions with observations.
Reduced order rainfall-discharge model for hydro-climatic data assimilation: a data-driven approach
Authors: Douch Karim , Saemian Peyman , Sneeuw Nico
Published: February 2023

Hydro-climatic variables such as precipitation (P), evapotranspiration (ET), terrestrial water storage (TWS) or river discharge define the terrestrial water cycle at local and global scales. The robust detection and quantification of steady trends in these variables require analysing sufficiently long time series of observations. Yet, historical discharge records may suffer from long data gaps or simply be too short; different reanalyses or data-driven models of P and ET often show large discrepancies and the associated uncertainty is not systematically provided. Finally, TWS has been observed only since the launch of GRACE in 2002 and also suffers from dozens of missing epochs.Here, we present a 3-step approach to consistently reconstruct the historical time series of TWS and discharge at the catchment scale. In the first step, we use in-situ discharge observations and TWS anomaly derived from GRACE(-FO) observations to identify a reduced-order and mass-conserving rainfall-discharge model of the catchment. In the second step, the model is run with different precipitation and evapotranspiration data sets to select the pair P and ET reproducing most accurately the observed discharge and TWS. If necessary, the resulting net water flux (P-ET) is adjusted with a bias to improve the simulation accuracy. lastly, we apply a Bayesian smoother such as the Rauch–Tung–Striebel smoother to estimate TWS and discharge along with their respective uncertainty over the period covered by the P-ET time series. Critical to the proposed approach is the rainfall-discharge model identification. Here, we assume that the observed monthly-averaged discharge at the outlet is primarily driven by the TWS in the upstream catchment. As a consequence, we first estimate a storage-discharge model in the form of a continuous-time differential equation. This equation is subsequently coupled with the water mass balance equation to form the rainfall-discharge model. Remarkably, this final model is estimated independently of any P and ET models.Finally, we apply the proposed approach to Amazonian and Siberian catchments for a period spanning from 1980 to 2020. In the first case, linear and time-invariant models capture with reasonable accuracy the observed drainage dynamics. In contrast, non-linear or linear and time-variable models are necessary to take correctly into account the temperature-dependent snow and ice accumulation and thaw in the case of Siberian catchments.
Communicating meteorology: the University Partnership for Atmospheric Sciences (UPAS)
Authors: Thiele-Eich Insa , Uebachs Annika
Published: February 2023

The recently formed University Partnership for Atmospheric Sciences (UPAS) has been developed by student, academic staff and faculty representatives of the 10 German universities that provide consecutive studies in the field of meteorology through both Bachelor (BSc) and Master (MSc) programmes. UPAS is open to all meteorologists at all levels and is supported by an executive office hosted at the University Bonn. The explicit goal of UPAS is to secure, guide and further develop meteorology as a study and research field at German universities while also synergizing the efforts of the individual partners in the four areas of

Attracting suitable students,
Excellent education,
Synergies for successful science, and
Societal and Community outreach.

We will present our efforts of the past months, which included e.g. establishing an international network of early-career scientists in the field of meteorology through virtual monthly meet-ups as well as an annual early-career scientist conference, testing experiments focusing on climate change and developing a handbook for meteorologists to showcase these experiments in a classroom near them, and using tools on our website to interact with the general public. Our upcoming plans include strategically entering the world of online and social media to both communicate to and interact with meteorology students in addition to interested citizens regarding meteorology as a whole, as well as establishing a nation-wide citizen science project. We are also interested in forming international ties to networks with similar objectives.
 
Sensitivity of Satellite Lidar-Radar Cirrus Retrievals to PSD Assumptions: DARDAR-Nice v2 and Simulator
Authors: Sourdeval Odran , Bartolome Garcia Irene , Penide Guillaume , Krämer Martina
Published: February 2023

Ice clouds constitute a challenge to satellite remote-sensing due to the variability of their microphysical properties. A central parameter to understand and represent ice clouds in modelling as well as in remote-sensing is the ice particle size distribution (PSD), whose shape largely varies depending on the environmental conditions in which the ice cloud has formed and evolved. This shape is typically assumed in satellite retrieval algorithm, for instance as a mono-modal gamma-modified distribution. Our representation of PSDs has greatly improved over the last decades, largely due to novel parameterisation methods as well as the increasing availability and accuracy of in-situ measurements that can serve as a solid basis to calibrate retrieval algorithms.This study investigates the impact of the PSD shape assumptions on cirrus retrievals obtained from lidar-radar satellite observations (DARDAR-Nice), with a strong focus on the ice crystal number concentration. Recent in-situ measurements from the JULIA dataset were recently processed to propose new parameterisations of the PSD that offer a better representation of small ice concentrations. The added-value of considering the observed bi-modality when representing PSDs for remote sensing applications was also discussed. We here assess the consequences of including such new parameterisations in DARDAR-Nice. Comparisons between v1 and v2 (offering updated PSD assumptions) of this satellite product are also discussed.Finally, preliminary results from a DARDAR-Nice simulator will be shown. This simulator allows to perform synthetic lidar-radar observations and retrievals on high-resolution cloud model outputs. Comparisons between the model “truth” and synthetic retrievals will be investigated and discussed in the context of underlying PSD assumptions.
Fugitive Methane Across the UK Gas Distribution Network from Terminals to Cities: Characterisation and Methodology Development
Authors: Lowry David , France James , Fernandez Julianne , al-Shalan Aliah , Fisher Rebecca , Vogel Felix , Nisbet Euan
Published: February 2023

Fugitive emissions from gas distribution are a top target for reduction of CH4 emissions to atmosphere with the UN considering that emissions from fossil fuel activities can be reduced by 61% (UN, 2021). Once the emissions are identified there are mitigation solutions to stop the leaks far more easily than emissions from waste and agricultural sectors. The RHUL group has identified fugitive methane from UK sources using a mobile survey vehicle since 2013, initially to identify plumes and characterise the emissions by source category using isotopic signatures (δ13C) and ethane to methane ratios (C2:C1). More recent measurements have focussed on CH4 emissions from buried city gas pipelines, primarily London, and development of methodology for interpreting data from a range of different high-precision instruments. Much of the gas in the UK distribution system has very similar charactersistics once mixing downstream of terminals has taken place. This is typically characterised by δ13C signature of -39 ± 1 ‰ and C2:C1 of 0.055 ± 0.015, which make it distinct from agricultural, waste and combustion CH4 sources. The small proportion of gas coming from the Southern North Sea and Morecambe Bay fields (now <20%) is more enriched in 13C (-34 to -28 ‰) and terminals receiving gas from these locations have different emission signatures; that for the Bacton terminal can be traced downstream toward London. City measurements by Picarro 2301 and LGR UMEA of London and Birmingham pipeline gas leaks in 2019 have been used to quantify emissions using methodology developed by Weller et al. (2019) and refined by Maazallahi et al. (2020). A total estimated emission for the Greater London area of 2.2 kT (Fernandez et al., in prep.), is much lower than the inventory suggests and lower than estimates and from aircraft or fixed site measurements. While fugitive gas emissions from rural areas (pipelines and above-ground infrastructure) are much larger than the inventory suggest, lowering expected urban emissions, and small peaks of <200 ppb cannot be definitively characterised as gas leaks, leading to underestimation, the methodology for leak emissions estimation needs further refinement for dense urban environments. A range of instruments measuring at 0.3 to 10Hz and different emissions methodologies are currently being assessed through repeat surveys of some London boroughs. Maazallahi et al., 2020, Atmos. Chem. Phys., 20, 14717–14740, https://doi.org/10.5194/acp-20-14717-2020United Nations Environment Programme, 2021, Emissions Gap Report 2021: The Heat Is On – A World of Climate Promises Not Yet Delivered, NairobiWeller et al., 2019, PLoS One 14, e0212287, https://doi.org/10.1371/journal.pone.0212287
Molecular rearrangement of bicyclic peroxy radicals: key route to aerosol from toluene
Authors: Iyer Siddharth , Kumar Avinash , Savolainen Anni , Barua Shawon , Garmash Olga , Seal Prasenjit , Rissanen Matti
Published: February 2023

Aromatic compounds contribute significantly to the formation of secondary organic aerosol (SOA) that have implications on health and on climate. Toluene is the most abundant aromatic compound in the atmosphere and is emitted through anthropogenic activities such as incomplete combustion and industrial processes. To form SOA, participating vapors such as toluene need to have sufficiently low volatility, which in practice implies molecules with multiple oxygen containing polar functional groups called highly oxygenated organic molecules (HOMs). The oxidation of toluene by OH can lead first to bicyclic peroxy radicals (BPR), and then to HOM. While the formation of HOM has been shown to be efficient, the underlying molecular level mechanism has been challenging to accurately elucidate because of the sheer number of potential pathways. This leads to a major gap in the understanding of the formation of SOA from toluene in the atmosphere. In this work, we conclusively demonstrate for the first time that the toluene derived BPR is unstable under atmospheric conditions and undergoes spontaneous molecular rearrangement to lead to completely ring broken RO2s at rates competitive with bimolecular reactions with NO even under polluted conditions. Intriguingly, several of the closed shell products deriving from the BPR are likewise unstable and decompose in finite timescales. This is relevant for those aromatic compounds that lead to BPRs that are otherwise stable against rearrangement reactions, providing, e.g., a long-range transport vehicle for NOx similar to peroxyacyl nitrates (PAN). Using quantum chemical calculations and master equation simulations that account for energy non-accommodation, we elucidate the molecular level mechanism of the subsequent autoxidation of the ring broken RO2s that leads rapidly to the HOM O9-RO2. Furthermore, using targeted flow reactor experiments of the OH reaction of toluene and partially deuterated toluene with nitrate chemical ionization mass spectrometry (CIMS) detection, we corroborate the proposed new mechanism. This is the only unambiguous reaction pathway to toluene derived HOM reported to date, and it has implications on the aerosol and ozone forming potential of toluene.
How does the weather affect the response of porous hose wind noise reduction systems?
Authors: Assink Jelle
Published: February 2023

In order to reduce the observation of wind and turbulence on infrasound sensors, wind noise reduction filters are in place at most infrasound stations. The use of such filters is essential to obtain low background noise levels, which in turn facilitates detection of low signal-to-noise (SNR) infrasound signals. Most filters operate by spatially integrating the pressure field in the vicinity of an infrasound sensor. While the turbulent pressure (partially) de-correlates over the spatial length scale of the filter, the infrasound wave remains coherent. Infrasound arrays that are part of the International Monitoring System make use of advanced pipe array structures that have been designed for long-term deployments. The response is of these systems is stable and well understood. In contrast, many experimental infrasound arrays have relied on the use of porous hoses for wind noise reduction. Porous hoses appear to be efficient, yet cost-effective solutions for short term deployments. Over longer timescales, however, it is known that the response of the hoses can vary significantly and that the hoses can degrade over time. In this work, we investigate the varying response of the porous hoses at the De Bilt Infrasound Array in the Netherlands, using a reference infrasound sensor without hoses. Since a weather station is co-located with the infrasound array, this allows us to study the relationship between the response of the hoses and various meteorological parameters. It is found that under dry conditions, the hoses act as a low-pass filter with a corner frequency around 1.8 Hz, which is consistent with earlier work. We shows that the higher frequency signals with sufficient SNR can be reasonably well reconstructed after a deconvolution step. Under wet conditions however, the hoses become highly absorptive. This can affect observations down to 0.1 Hz. The excess attenuation can be attributed to the presence of rain and/or dew. Although these effects appear to be reversible to some degree, this work shows that care must be taken in the interpretation of data from infrasound arrays that make use of porous hoses.
Magnetic helicity dynamics in compressible isothermal MHD turbulence
Authors: Teissier Jean-Mathieu , Müller Wolf-Christian
Published: February 2023

Magnetic helicity dynamics are important in the context of the generation of large scale magnetic structures from small scale fluctuations. Up to the present day, these dynamics have remained largely unexplored in compressible plasmas. We present new results from direct numerical simulations of isothermal magnetohydrodynamic turbulence, with Mach numbers ranging from 0.1 to 10 by employing higher-order numerics. A mechanical driving injects kinetic energy at the largest scales, while a small scale electromotive driving injects helical magnetic fluctuations. A large-scale sink of magnetic energy leads to the formation of a turbulent statistically stationary state, which is analyzed, extending the results on nonlinear cross-scale transfer presented in doi:10.1017/jfm.2021.32 and doi:10.1017/jfm.2021.496.
Theory of drying of polymer solutions in porous media
Authors: Carminati Andrea , Benard Pascal , Lehmann Peter
Published: February 2023

Plant roots and bacteria release in soils polymeric blends of substances which alter the physics of soil water flow and support life in soils. They adsorb water, decrease the surface tension of the soil solution and increase its viscosity, and, more generally, they change the soil solution into a non-Newtonian liquid with viscoelastic properties. A theory of drying of polymer solutions in porous media is missing and it is needed to understand the feedback between physics of porous media and life in soils. It was observed that during drying polymer solutions are deposited as thin surfaces spanning multiple pores and that these depositions are associated with a decrease in evaporation rate. Here, we provide a physical explanation of surface formation. The modeling framework includes Darcian flow across the polymeric network driven by a gradient in water potential. As the polymer dries and air invades the pore space the polymer network is stretched. The stretching causes a stress in the polymer network that alters the relation between water potential and polymer concentration: the more stretched is the polymer network the smaller is the spacing between the polymers at a given water potential, and the lower is the permeability of the network. The model predicts that at a critical point during evaporation there is an asymptotic increase in polymer concentration at the gas-gel interface corresponding to the deposition of solid-brittle interfaces. The onset of this glass transition depends on flow rate and pore size, with earlier deposition for fast high evaporative fluxes and small pores. The model explains why evaporation is suppressed much earlier and more significantly when the polymer solution dries into a porous medium, in comparison to the case when the polymer solution is free to dry outside a porous medium.
Palaeoproteomics of skeletal fossils reveals hominins evolution and behaviours: several case studies from East Asia
Authors: Xia Huan , Zhang Dongju , Chen Fahu
Published: February 2023

The analysis of ancient DNA and paleoproteomics can identify biological materials, such as fossils, construct phylogenetic relationships between extinct and extant species, and has been widely applied in archaeology and paleontology. In general, proteins degrade more slowly than DNA and could be persevered in fossils over 60 million. Although less phylogenetic information was obtained than ancient DNA, paleoproteomics analysis becomes an indispensable method for studying biological evolution and hominins behaviours with its high throughput, low cost, and low contamination. Based on several cases of applying paleoproteomics analysis in archaeological and paleontological sites from East Asia, I will present two main methods, LC-MS/MS and MALDI-TOF MS, and how paleoproteomics reveals the evolutionary history and behaviours of hominins in East Asia, aiming to provide a research background of this field.
Groundwater Storage Changes in the United States using Baseflow Recession Method: Comparison with GRACE, and Observation Well Data
Authors: Hameed Mehvish , Nayak Munir , Ahanger Manzoor
Published: February 2023

Groundwater is a major source of water supply over most regions, accounting for nearly one-third of all water abstraction globally. However, due to overreliance on this resource, many aquifers around the United States have experienced rapid depletion, while some aquifers have seen increasing water levels due to extensive recharge efforts. It is essential to have a comprehensive understanding of the rate at which groundwater storages are changing to assess the potential availability of groundwater in the future. In this work, we estimate groundwater storage changes across more than 1000 watersheds over the US from a proposed algorithm for baseflow extracted using streamflow and precipitation observations. We also study the spatial and temporal variations in the characteristic of baseflow recession. We compare the storage change estimated from baseflows with those obtained from the estimates from the Gravity Recovery and Climate Experiment (GRACE) and observations from monitoring wells. The results help in validating the application of the proposed baseflow-based storage estimates in different aquifers and climatic regions. The proposed approach is simple and computationally efficient for estimating baseflows and groundwater storage changes in poorly-gauged watersheds.
Modelling lahars at Merapi (Indonesia) and Rainier (USA) volcanoes using Titan2D and LAHARZ computer models
Authors: Chopra Tanvi , Cortés Joaquín
Published: February 2023

Lahars are a type of volcanic hazard that can have devastating impacts on surrounding environments and communities. They are difficult to predict and study, making them particularly dangerous. In order to better understand the extent and potential impacts of lahars, this study utilizes digital simulations and GIS technology to model lahar activity at Mount Merapi in Indonesia and Mount Rainier in the United States.The study employs the use of two computer codes, Titan2D and LAHARZ, to generate visual outputs for GIS systems. Titan2D is used to model near volcano hazards, such as pyroclastic density currents, using a Digital Elevation Model (DEM) of the volcano. These outputs are then remobilized as lahars and extended along valleys using LAHARZ, resulting in outputs that mimic real-life scenarios.Both Mount Merapi and Mount Rainier are located near densely populated settlements and have the potential to generate lahars, indicating a possibility for significant hazards. Using a 30-metre DEM and varying parameters, this study simulates lahars of varying volumes ranging from 125,000 m3 to 16,000,000 m3 in order to identify the extent of the hazard in multiple scenarios.Both Titan2D and LAHARZ have been tested individually by researchers in the past and have been found to accurately recreate past events. This study tests their combined use as a tool for producing hazard maps viewable in GIS, which can aid in hazard prediction and analysis. The resulting hazard maps for both Mount Merapi and Mount Rainier are found to be comparable to existing hazard maps for these volcanoes, suggesting that the combination of Titan2D and LAHARZ is an effective tool for hazard analysis.
Forest fire plumes in the Paris region (France) during summer 2022, the spoor of a schorching summer
Authors: Petit Jean-Eudes , Gros Valérie , Favez Olivier , Simon Leila , Kalalian Carmen , Brugère Etienne , Borbon Agnès , Dupont Jean-Charles , Abbou Grégory , Ghersi Véronique , Michoud Vincent , Di Biagio Claudia , Formenti Paola , Cantrell Christopher , Gration Aline , Brito Joêl , Dusanter Sebastien , Jamar Marina , Haeffelin Martial
Published: February 2023

In the context of climate change with increasingly pronounced impacts, year 2022 in France has been the warmest year ever observed. It has been the case more specifically during July, when a severe heatwave occurred across North-Western Europe. Sea-level temperature anomalies jumped over +12°C, especially in the Western half of France, pushing back all-time records. Associated to extreme temperature occurred a severe drought, with long-lasting precipitation deficit throughout the year, which was amplified during July. With around 80% deficit, July 2022 in France has also been the driest ever recorded. These singular meteorological conditions were therefore a fertile ground for forest fires. Around 70 000 ha of forest have burned in France during 2022. The South-West region has been particularly impacted during July 2022, as well as other areas which are not usually subject to this kind of events (Brittany, Center, Paris region).
During July 2022 occurred the ACROSS field campaign within the Paris region, where several sites following a South-West to North-East transect provided comprehensive characterization of atmospheric composition. Namely Rambouillet station (forest, SW of Paris), SIRTA (peri-urban, SW of Paris), PRG (urban, Paris center) and Chatelet Les Halles (urban, Paris center). These sites were equiped with state-of-the-art instrumentations to characterize aerosols and reactive gases. On July 19th, an intense biomass burning plume went through the Paris region, with PM10 concentrations reaching more than 150µg/m3. The experimental effort during that period is therefore a unique asset in order to characterize the composition of this episode.
Most of the sites, during that episode, record high concentrations of carbonaceous aerosols (organic matter and black carbon) and Volatile Organic Compounds tracers of biomass burning (eg acetonitrile, benzene, toluene). Temporality of the episode, atmospheric dynamics and air mass pathways, suggest the transport of a biomass burning plume from South-Western France, more than 600km away from Paris. However, aerosol size distribution surpringly reveals the influence of local fires occuring near some of the sites, at almost the same time. This work is therefore focusing on the different properties of different plumes mixing at the same time over a densely urbanized region. These differences can be highlighted by source apportionment, combined with size distribution, as well as oxydation state of organic aerosols.
Remote sensing techniques and tools to map marine bioindicators and their potential responses to anthropogenic pollutants: SPECTRAL SIGNATURES OF POSIDONIA OCEANICA AND CYSTOSEIRA SP. AND FIRST RESULTS
Authors: Varini Fabrizio , Madonia Alice , Scanu Sergio , Piermattei Viviana
Published: February 2023

The ASI-STOPP project, aims to study marine bioindicators using new aerial platforms (HAA), equipped with multispectral sensors, able to remain in flight in the stratosphere for several months, allowing the study of anthropogenic pollution events on mesoscale (space and time) with high resolution, precision, cost-effective and practically. In this context, to validate the data recorded by the sensors placed on the High Altitude Airships ad hoc measurement protocols must be drawn up and calibration tests must be carried out in the laboratory on the target bioindicators (algal and marine plant species) present in the areas of interest. The first activities carried out concerned (i) the identification of the coastal target species present in the study areas of the project (e.g., Posidonia oceanica and Cystoseira sp.) fundamental for marine ecosystems to which they provide food, shelter for marine life, and oxygen; (ii) the selection of environmental specific pollutants (e.g., Chromium) that could affect algal and plants well-being.A literature study and review of the spectral responses of the selected species have been carried out, which allowed us to build a summary table including all the methodologies applied in this research field. This work allows us to select the most suitable measurement protocol for our experiments.In situ sampling was carried out and marine algal and plant species were transported to the laboratory for subsequent experiments, following the standard procedure reported in the literature to guarantee their adaptation and prevent samples. Finally, the spectral response of the selected species to the Chromium was assessed, according to the drafted measurement protocol and referring to the technical specifications of the Stellarnet Spectrometer. Spectral signatures of the selected species and data acquired were then compared with those obtained from the Cr pollutant enrichment experiments performed in the laboratory.
Long-term hydrologic connectivity on the Australian dryland margins: evidence from the Willandra Lakes World Heritage Area over the last 60 ky
Authors: Fitzsimmons Kathryn , Fischer Markus , Nowatzki Maike , Lauer Tobias , Mishra Kanchan , Stern Nicola
Published: February 2023

The recent catastrophic flooding across the world’s driest inhabited continent – Australia – has highlighted an urgent need to understand the climatic (atmospheric) and hydrological (land surface) mechanisms comprising hydroclimate. Records of past hydrologic change may help in this endeavor by informing us about different hydroclimate states and their manifestation on the land surface. By virtue of its antiquity, aridity and relative paucity of available sediment, however, the Australian continent preserves few records of long-term hydroclimate. As a result, we know little about long-term water availability and the drivers of surface hydrology and climate circulation, particularly for the dry inland regions where water resources and sensitive land surfaces need to be carefully managed. One of the few areas in dryland Australia which preserves semi-continuous deposition of hydrologic change is the Willandra Lakes system. The Willandra Lakes are located on the semi-arid desert margin of southeastern Australia, yet its headwaters lie in the temperate eastern highlands. Long-term lake filling and drying is consequently driven by rainfall in the headwaters and hydrologic connectivity both across the catchment and between the lakes. These environmental changes – both long and short in duration – are recorded in the sediments of the downwind transverse dunes (lunettes). In this study we investigate long-term hydrologic connectivity across the catchment and between the lakes. Our approach uses a novel integration of both classical lake-level reconstruction based on lunette sedimentology, stratigraphy and luminescence geochronology, with hydrologic modelling of key event time slices over the last 60 ky, fed into a palaeoclimate model. We characterize the land-surface response to various hydroclimate states, so improving our understanding of dryland atmosphere-hydrosphere interactions. 
Modelling The Water-Energy-Food-Ecosystem Nexus Using Data-Driven Methods
Authors: Jonsson Elise , Teutschbein Claudia , Grabs Thomas , Todorovic Andrijana , Francisco Andreina , Blicharska Malgorzata
Published: February 2023

Attaining resource security in the water, energy, food, and ecosystem (WEFE) sectors is paramount in order to fulfill many of the sustainable development goals. To obtain a holistic understanding of this WEFE nexus and assess the impacts of policy decisions, climate change, and other interventions, a system dynamics approach to modelling has been encouraged. Due to the multiscale, nonlinear nature of this nexus and a recent data deluge in the WEFE sectors, we propose the use of data-driven methods, which rely on dimensionality reduction and machine learning algorithms to find low-rank patterns and parsimonious models in big data sets. As these methods have proven highly successful within other scientific disciplines, we evaluate the prospect of using a data-driven approach to address key issues in nexus research based on analogous case studies from these disciplines. Specifically, we address three key issues with nexus modelling: model discovery, extreme events, and scenario analysis. We first consider how to identify nonlinear dynamical equations from chaotic, noisy, multiscale, and variable-deficient measurements using algorithms like SINDy and HAVOK, which have already been employed on a multitude of physical, biological, and chemical systems. We then investigate how to model the cascading impacts of extreme events on the nexus based on data-driven models of disease outbreak, as well as rapid model recovery after an unprecedented extreme event. Finally, we look into how to employ data-driven control, using case studies in flight control and drug intervention modelling, for the purpose of assessing how policy decisions, climate change, or population growth may be evaluated when modelling the nexus. This can provide tools for stakeholders to see what systemic impacts their decisions might have, and how they can attain synergies between the WEFE sectors. While many studies have conceded that nexus modelling is highly individualized based on the selected region, sectors, and data availability, this overview highlights that a generalized systematic approach to nexus modelling may still be possible, despite these challenges.
Urban Flood Forecast using an Open Source Coupled 1D1D SWMM Model for Real-Time Applications
Authors: Høegh Ravn Nanna , Baumann Henry , Schaum Alexander
Published: February 2023

Due to climate change, heavy rainfall events are occurring more frequently and at a higher rate. At the same time, the sewer system is often not designed to handle such a large amount of precipitation, which often leads to flooding of certain critical areas. However, modern sensor technology for monitoring the filling and flow rates in the sewer system, as well as for monitoring and forecasting rainfall probabilities, including quantity information, form a good basis for developing modern multifunctional early warning systems, which can serve as an aid for decisions on action. Urban water drainage systems represent complex networks with nonlinear dynamics and different types of interactions. This yields an involved modelling problem for which different off-line simulation approaches are available. Nevertheless, these approaches cannot be used for real-time simulations, i.e., running in parallel to weather now- and forecasts and enabling the monitoring and automatic control of urban water drainage systems. Alternative approaches, used commonly for automation purposes, involve parameterized linear delay systems, which can be used in real-time but lack the necessary level of detail, which is required for adequate flood risk prognostics. Given this setup, an approach for the effective modelling of detailed water drainage systems for real-time applications implemented with the open-source Storm Water Management Model (SWMM) software is addressed and exemplified for a part of the water drainage system of the city of Flensburg in northern Germany. Additionally, a freely available early-warning system prototype is introduced and used to combine weather forecast information on a 2-h prediction horizon with the developed model and available measurements. This prototype is subsequently used for data assimilation using the ensemble Kalman filter (EnKF) for the considered area in Flensburg. The project presented here is part of the NEPTUN project. NEPTUN is financed by Interreg Deutschland-Danmark with means from the European Regional Development Fund. 