bluuebunny/crossref_metadata_2025 huggingface dataset:
Retrieving the rainfall signature from the isotope composition of speleothem fluid inclusion water: progress and pitfalls
Authors: Vonhof Hubert , Markowska Monika , Levy Elan , Martinez Garcia Alfredo , Nicholson Sam , Schroeder Julian
Published: February 2023

Over recent years, a growing number of case studies have highlighted the relevance of fluid inclusion (FI) isotope analysis on speleothem calcite for the reconstruction of rainfall isotope variation back in time. Multiple studies documented FI isotope results consistent with projected local meteoric water line values, demonstrating that FI isotope analysis can provide unique and quantitative paleohydrological data. Several other studies have shown that FI isotope data can be compromised due to diagenetic effects, or (petrography-controlled) analytical artefacts. Such diagenetic or analytical artefacts typically have a detrimental impact on the accuracy of isotope equilibrium-based cave temperatures calculated from paired oxygen isotope values of FI water and host calcite.Here, we will highlight some recent FI isotope records, discuss current views on the recognition of FI isotopic artefacts, and provide guidelines for the interpretation of FI isotope data as a paleo-rainfall proxy, with particular focus on direct comparison to novel TEX86 paleotemperatures that can be derived from the same speleothem calcite.
Radiation Effects and other features in the Laser Ranging Interferometer Data
Authors: Misfeldt Malte , Bekal Pallavi , Müller Laura , Müller Vitali , Heinzel Gerhard
Published: February 2023

The GRACE-FO mission (2018-now) hosts the novel Laser Ranging Interferometer (LRI) that measures the inter-satellite distance with a previously unprecedented precision of better than 200 pm/sqrt(Hz) at Fourier frequencies above 1 Hz. Gravity information of the underlying Earth is retrieved by combining this ranging measurement with orbit information and accelerometer data.In this talk, we will explore sporadic signals in the measured phase data that might be caused by radiation interfering with electronics and resulting in so-called Single-Event Upsets (SEUs). Radiation effects are known to, e.g., cause reboots of computers in space and affect data stored in memory cells. In the ranging data of the LRI, SEUs manifest as short-lived peaks that can be simulated, modeled, and removed in post-processing. Over four years mission lifetime, we identified 29 such events.Further, we will also address other events that we call Momentum Transfer Events (MTEs), where the satellites experience short-lived accelerations measured by both, LRI and Accelerometer. The majority of these events are likely caused by tiny particles, micrometeorites, or space-debris, that hit the spacecraft and cause a change in velocity. As these velocity changes are actually physical effects, they might influence the gravity field recovery process on short arcs if they remain unmodeled.The analysis shown here may help future missions, which will likely base on an improved LRI instrument, to understand and eventually mitigate these kinds of disturbances already in the instrument design phase. For the current mission, the proper removal of unintended features might become beneficial in future gravity field processing with reduced background and modeling noises.
The generation, dissipation and geological implication of grain-scale stress variation in metamorphic rock
Authors: Zhong Xin
Published: February 2023

Metamorphic rocks are composed of minerals formed within a wide range of pressure-temperature (P-T) conditions. These minerals possess distinct physical properties with respect to their thermo-elasticity, viscosity and plasticity etc. When far-field nonhydrostatic stress was present during tectonic deformation or the P-T conditions were changed during burial or exhumation processes, grain-scale stress variation can be developed to maintain mechanical equilibrium. The induced stress variations can also be released over geological time. The magnitude, effect and geological implications of the preserved stress variations have been investigated and better understood in recent years, but a lot remains to be explored. It is important because it may as well open an opportunity to decipher the overseen information stored in the rock that is difficult to be detected or achieved with conventional methods.The geological implication of grain-scale stress variation is directly manifested by a simple mineral inclusion-host system, such as quartz or zircon inclusion in garnet. The different thermal-elastic response between the inclusion and host upon P-T changes will result in a residual stress stored in an entrapped mineral inclusion. The inclusion stress (strain) can be directly measured with e.g. Raman spectroscopy. Combined with an elastic model, it is possible to obtain constraints on the entrapment P-T conditions. This elastic thermobarometry technique has been applied in many recent petrological studies because no global or local chemical equilibrium assumption is needed. However, it relies on the inclusion-host system being elastic and neglects the non-elastic behavior of minerals. As an example, I will present an integrated observational, experimental and numerical modelling work that highlights the importance of considering non-elastic behaviour of the mineral. The heating experiment shows that under conditions at which free fluid is present, a garnet host will be drastically weakened and partially release the inclusion pressure. This is further correlated with a nappe-scale study in the Adula nappe, Alps. A smooth T gradient is found increasing from the north (500-550 oC) to the south (700 oC) using the Zr-in-rutile thermometer. However, the entrapment P calculated with the quartz inclusion in garnet barometer demonstrate a GPa level steep drop in the middle-south, where the rocks have been hydrated during retrograde metamorphism and abundant micro-hydrous inclusions (e.g. chlorite, amphibole) are found in the garnet. It is interpreted that a combined effect of temperature and water fugacity will drastically speed up the inclusion pressure relaxation on a regional metamorphic scale. In the end, it is highlighted that mechanics with non-elastic stress-strain (rate) relationships are potentially needed when dealing with the generation and dissipation of the stress variations in metamorphic rocks that underwent retrograde hydration or very high T conditions to better extract geological information.
A public domain data-based modeling of long-term variability of Jupiter’s inner electron radiation belt
Authors: Santos-Costa Daniel , Oyafuso Fabiano A. , Levin Steven M. , Connerney John E.P. , Woodfield Emma , Keebler Timothy , Velusamy Thangasamy , Han Sooman , de Pater Imke , Jun Insoo , Garrett Henry B. , Wilson Rob , Ebert Rob W. , Allegrini Frederic , Gladstone Randy , Kollmann Peter , Mauk Barry , Kurth William , Becker Heidi N. , Bolton Scott J.
Published: February 2023

Until the arrival of Juno at Jupiter in 2016, the inner electron radiation belt dynamics has been examined from ground-based observations of Jupiter’s Synchrotron Emission (JSE) and theoretical modeling of the relativistic electron population. Simulations of JSE variability on month-to-year timescales only confirm a partial control of the Jovian Electron Radiation Belt (JERB) by large-scale solar-wind-driven particle transport. Juno prime mission and first years of the extended mission provide unique measurements of JSE from within JERB environment allowing us to further address the origins of JSE variability on a timescale of months. In the present work, we use Juno MicroWave Radiometer (MWR) data from mid-2016 to mid-2022 at different wavelengths to support our investigation of the origins of JERB dynamical behavior. Juno/MWR data from NASA Planetary Data System, ground-based observations of Jupiter and simulated Heliospheric Environment (HE) at the giant planet are combined to constrain the modeling of long-term variability of JSE as it would be observed from Earth. The Juno-data constrained trend of JSE at 11.5-cm wavelength is combined with single-dish observations to cover a multi-decade observation period. Using a simulator of JSE that accounts for the influence of physical parameters on jovian electron belts distributions, we present simulations of JSE to discuss the connection between JERB and HE and identify the magnetospheric physical processes (e.g., particle source and transport, interactions with planetary environment) which might have controlled JSE for the period 1962-2022. Acknowledgments: Key data processing, JERB model improvements and simulations of Juno/MWR measurements are carried out at Southwest Research Institute and primarily funded by NASA NFDAP program. This work benefits from collaborations with various Juno instrument teams and also from a larger science community.
Quantifying volcanic gas emission rates from infrasound and SO2 cameras: potentials, limitations, and volcanological implications.
Authors: Delle Donne Dario , Lacanna Giorgio , Bitetto Marcello , Ulivieri Giacomo , Ripepe Maurizio , Aiuppa Alessandro
Published: February 2023

Volcanic degassing, a persistent manifestation of active volcanoes, provides crucial information on the dynamics of the magmatic feeding systems, and allows identifying the phases of volcanic unrest in the runup to volcanic eruptions. While thus determining volcanic degassing rates is a central topic in modern Volcanology, direct volcanic gas flux observations by classic spectroscopic techniques are challenged by (i) the need of adequate illumination (by sunlight) and clear weather conditions (ii) difficulties in robustly estimating plume speed velocity and transport direction, and (iii) a variety of optical and radiative transfer issues. Because of these, volcanic gas flux records are often sparse and incomplete, and affected by intrinsic noise that may prevent from fully resolving the gas emission changes associated with changing volcanic activity. To overcome such limitations, measuring the infrasound produced by the expansion of over-pressurized volcanic gas in the atmosphere, using infrasonic arrays, offers as a promising alternative/complementary tool to quantify and locate degassing at active volcanoes. Here, we report on 2-year long (April 2017—March 2019) period of combined measurements of the SO2 flux and of volcano-acoustic emissions produced by regular mild persistent strombolian activity and passive degassing of Stromboli Volcano (Sicily, Italy). These were obtained by a permanent monitoring SO2 camera and a five-element short-aperture (~300 m) infrasonic array. Our results highlight substantial temporal changes in degassing activity, that reflect the recurrent episodes of activations/inactivation of multiple distinct degassing sources within the crater area, as coherently tracked by SO2 and infrasound together. A simple waveform modeling of the infrasonic record, assuming a monopole acoustical source, suggests that infrasonic degassing, comprising of explosive events and continuous puffing activity, dominates the total persistent degassing budget as tracked by the SO2 camera.
EuVeM2022: a new European GNSS velocity model
Authors: Steffen Rebekka , Steffen Holger , Kenyeres Ambrus , Nilsson Tobias , Lidberg Martin
Published: February 2023

The European continent is divided into several tectonic plates and velocity variations appear along plate boundaries. However, velocity changes inside a tectonic plate can also occur due to local effects or other geodynamic processes, which is of interest for researchers trying to understand intraplate deformations in the horizontal and vertical directions. These changes can be observed by a dense network of GNSS (Global Navigation Satellite System) stations or more recently by the usage of InSAR (Interferometric Synthetic Aperture Radar). However, a dense GNSS network cannot be maintained over large areas due to, e.g., high costs and topographical obstacles, thus a regional velocity model to study intraplate deformation has to be obtained via an interpolation of scattered GNSS station velocities. The obtained velocity models can be used to estimate strain rates, which can be compared to existing seismic hazard models. In addition, in areas with a limited amount of seismic information, strain rates obtained from GNSS velocity models can provide a useful input for seismic hazard models.The increased availability of GNSS station velocities in Europe via the EUREF Permanent Network Densification (EPND) project (https://epnd.sgo-penc.hu) allows to obtain a complete picture of the horizontal and vertical deformation in Europe via an interpolation. Here, we apply a new interpolation technique to a velocity field solution from EPND. The homogenized and quality-checked velocity field is interpolated via a least-square collocation including the knowledge of existing plate boundaries to avoid a smoothing of nearby velocities on different tectonic plates. We also apply a moving variance approach to avoid effects of non-stationarity, which arise due to the variable station densities. The new 3D GNSS velocity model EuVeM2022 is used to estimate the strain rates and a comparison to seismic risk maps shows a clear correlation. However, in some areas increased shear strain rates as well as anomalies in the velocity model are visible where peak ground acceleration is not increased for example in Serbia.
Airborne radar radiometry and coastline mapping of the highly-specular subglacial terrain on Devon island
Authors: Gerekos Christopher , Rutishauser Anja , Scanlan Kirk , Wolfenbarger Natalie , Beem Lucas , Bott Jason , Blankenship Donald
Published: February 2023

The highly-specular terrain present under Devon Ice Cap in the Canadian Arctic Archipelago has been the target of several multi-instrument investigation campaigns. Initial analysis of radar sounder data collected by the High Capability Radar Sounder (HiCARS) and the Multichannel Coherent Radar Depth Sounder (McCORDS) over the area using state-of-the-art quantitative methods suggested the terrain could be a hypersaline lake [Rutishauser et al., Science Advances, 2018], however, newer seismic and conductivity measurements suggest a rigid, electrically insulating material that is incompatible with liquid water [Killingbeck et al., AGU, 2022]. Starting from the hypothesis that the highly specular terrain consists of flat and smooth sediments originating from a paleolake, we propose to revisit the original radar data and to apply more advanced dielectric and subsurface rough scattering hypotheses in order to constrain the materials present in the subsurface. We also propose to use subsurface interferometric clutter discrimination [Scanlan et al., 2020, Annals of Glaciology] on Multifrequency Airborne Radar-sounder for Full-phase Assessment (MARFA) data to map the coastline of the supposed paleolake. Combining dielectric and subsurface topographic information with modeling of the thermophysical evolution of the lake over interglacial cycles could reveal the history of the formation of the structure. Preliminary work on the new radar data analysis is presented.
Quantifying methane emissions from industrial activities: A novel helicopter-borne application for coal mine ventilation shafts in Poland and perspectives
Authors: Huntrieser Heidi , Förster Eric , Lichtenstern Michael , Pätzold Falk , Bretschneider Lutz , Lampert Astrid , Necki Jaroslaw , Jagoda Pawel , Taupin Quentin , Holl David , Roiger Anke
Published: February 2023

The Upper Silesian Coal Basin in southern Poland belongs to one of the strongest emitting regions of anthropogenic methane (CH4) in Europe. A major part of these CH4 emissions is related to the coal mining industry, which are in focus of the METHANE-To-Go-Poland project presented here. For the first time, a unique helicopter towed probe (HELiPOD) was used to capture CH4 plumes from selected coal mine ventilation shafts. The HELiPOD probe (weight 325 kg, length 5 m) was equipped with a 3D wind anemometer and trace gas in situ instrumentation (Picarro G2401-m and Licor-7700) to measure CH4 with a high precision (1 ppb) and temporal resolution (up to 40 Hz), which is necessary for a precise calculation of the CH4 mass flux. In June and October 2022, repeated upwind and downwind probing of the plumes from selected shafts (4 shafts, 16 flights) were performed at different horizontal distances from the source (~500 m - 5 km) and altitudes (~20 m – 2 km). This way, both the inflow amount of CH4 and the horizontal/vertical dispersion of the CH4 plumes from the shafts were captured. Depending on wind speed, wind direction and stability, suitable flight patterns were developed for every flight. In addition, two controlled CH4 releases were successfully carried out to prove the novel measurement concept. Mobile ground-based CH4 measurements complemented the airborne probing.In this presentation, mass flux calculations based on measurements from the two airborne CH4 instruments (with different measurement techniques) will be compared and uncertainties determined. Furthermore, CH4 mass flux calculations resulting from coinciding satellite measurements (GHGSat: swath width <15 km, spatial resolution <27 m) over the same ventilation shafts combined with high-resolved GEOS-FP wind data are presented. Finally, the uncertainties of the two different top-down approaches (air- and satellite-borne) are compared, in addition to different flight strategies. Comparisons with production data from the Polish coal mine industry are foreseen in near future (bottom-up approach). Subsequently, the same kind of airborne concept is envisaged for the METHANE-To-Go-Oman field experiment in autumn 2023, which will focus on CH4 emissions from the on-shore oil and gas exploration and production in Oman. Our collected data, funded by the International Methane Emissions Observatory (IMEO), will help coal, oil and gas companies as well as governments, to prioritize their CH4 emission mitigation strategies, actions and policies.
QUARTETnary - The card game about the geological time scale
Authors: van Zelst Iris , Pérez-Díaz Lucía
Published: February 2023

QUARTETnary is an educational card game about the geological time scale. Suitable for ages 7 and up, the game play follows that of the classic card game ‘quartets’, where players aim to collect sets of four cards belonging to a specific group (in this case, a certain geological time period). At the end of the game, the player with the most complete geological time line (i.e., the most quartets) wins the game! QUARTETnary consists of 15 different card quartets, each corresponding to a different geological eon, era, or period, starting in the Hadean and ending in the Quaternary. For each quartet, the cards represent key events, animals, or processes. For example, the Hadean consists of 1) the formation of the Moon; 2) Earth’s magma ocean; 3) the layered Earth; and 4) the first occurrence of liquid water on the planet. The cards specifically focus on geodynamic processes (i.e., the presence of supercontinents and the formation of various mountain ranges) and evolutionary developments (i.e., bacteria, land plants, mammals etc.) as well as major global events such as mass extinctions and the Cambrian explosion of life. They are illustrated in accordance with the official colour scheme set by the International Commission on Stratigraphy to ensure easy comparison with the official geological time scale.Here, we present an update on the development of QUARTETnary (with new cards!) and the projected launch schedule of QUARTETnary’s business plan and Kickstarter campaign, which we will use to produce and distribute the game.
The use of a low-cost monitoring dataset for sewer model autocalibration
Authors: Schütz Paul , Gutierrez Oriol , Busquets Silvia , Gunkel Michel , Caradot Nicolas
Published: February 2023

The management of urban wastewater systems and the associated modelling of these systems has become indispensable in today's world. In order for these models to represent reality as accurately as possible, a reliable calibration is essential. Water level data is used as a standard, but due to expensive sensors and harsh conditions in the sewer, data can only be collected at a few key points of the system. One novel solution, that has experienced an upswing in recent years, is collecting data using low-cost temperature sensors. Two sensors are needed; one is placed in the stream; the other is placed at the crest of the weir. In the case of dry weather, the sensor measures the air phase, whereas, in the case of Combined Sewer Overflow (CSO), the discharged storm and wastewater is measured. The start and end of a CSO event can be determined via the merging of measured temperature values in both points of the overflow structure. Due to this method, the duration of CSO events in a sewer system can be detected.In this work, the potential benefits of this novel method for model calibration are assessed. Therefore, autocalibration runs with water level data and fictional temperature data were carried out via OSTRICH for a SWMM model located in Berlin. Furthermore, calibration runs with a different number of measuring sites were performed, to evaluate the amount of necessary measuring sites for a reliable calibration. In order to be able to compare the different approaches, a calibration period of 19 events was first required for the respective datatype. Next, a validation period which consisted of 18 events was carried out and evaluated by the R² of three water level measuring sites for both approaches to ensure comparability. It was revealed that the calibration with duration data based on temperature sensors was able to achieve results as good as the conventional approach using water level data. Due to low spatial distribution of the measuring sites in the model, it could not be finally answered if more measuring sites would yield to even better results. However, already with one measuring site, promising calibration outcomes could be achieved and thus, offers an alternative for water utilities and practitioners.
Impacts of soil aggregation on the mobility of silicon in model variable charge soils
Authors: Li Zimin , Delvaux Bruno
Published: February 2023

Phytoliths are considered by biogeochemists and soil scientists as an important reservoir of mobile Si in the soil-plant system due to their relatively high dissolution rate. However, they are used in other disciplines as microfossils to reconstruct paleoenvironments because of their stability over millennia. Thus, on one side, phytoliths contribute massively to the continental export of dissolved silica to rivers and oceans, hence to the global silicon (Si) cycle, and, on the other side, they persist in soils and sediments. In addition to phytolith properties, soil processes can enhance their resilience, e.g., surface passivation through aluminum (Al) loading or redox-dependent iron (Fe) coating, pH buffering and aggregation.Here, we highlight the impact of aggregation on the release of dissolved Si (DSi) from aggregates built up from assemblages including organic matter, phytolith, quartz, clay mineral and Fe oxide. The source of DSi was assessed using Al/Si and Ge/Si ratios in aqueous extracts obtained kinetically.Aggregation significantly reduced the release of DSi particularly when variable charge components were amorphous. In this case, the source of DSi was unequivocally allophane, the dissolution of which was enhanced by pH below 5 (3.7-4.9). In contrast, in aggregates involving crystalline variable charge, DSi was released from phytoliths. In this case, Fe oxide had a significant effect on DSi release through both the aggregation process and pH control above 5 (5-8). Phytolith preservation in aggregates was effective at low oxide content (20 g kg-1). Yet, the increase in pH enhanced phytolith dissolution.Soil and sediments may thus contain two pools of phytoliths: fresh and stabilized phytoliths. The first reservoir is an important source of aqueous Si, and contributes actively to the Si soil-to-plant cycle and the DSi transfer to the hydrosystem. Yet, Si can be retrieved from the global Si cycle through phytolith entrapment in aggregates. This process contributes to the second pool of stabilized phytoliths. However, pH buffering significantly affects the impact of aggregation and the source of DSi. Indeed, acidic conditions enhance the dissolution of clay minerals while they decrease the dissolution rate of phytoliths
Organic, inorganic and total bromine observations around the extratropical tropopause and lowermost stratosphere
Authors: Rotermund Meike , Engel Andreas , Grooß Jens-Uwe , Hoor Peter , Jesswein Markus , Kluge Flora , Schuck Tanja , Vogel Bärbel , Wagenhäuser Thomas , Weyland Benjamin , Zahn Andreas , Zheng Siyuan , Pleilsticker Klaus
Published: February 2023

Organic, inorganic and total bromine (Brtot) around the upper troposphere and lower stratosphere (UTLS) were measured over southern Argentina and the surrounding regions extending down to the Antarctic Peninsula in September and November of 2019. These observations were recorded from the German High Altitude and LOng range research aircraft (HALO) as part of the Transport and Composition of the Southern Hemisphere UTLS (SouthTRAC) research campaign. Total bromine (Brtot) is inferred from measured total organic bromine (Brorg) added to inorganic bromine (Bryinorg). Brorg is comprised of the bromine summed from CH3Br, the halons, and the major very short-lived brominated species measured onboard HALO by the University of Frankfurt, while the Bryinorg is evaluated from limb measured BrO and CLaMS photochemical transport modelling (FZ Jülich) accounting for the BrO/Bryinorg ratio. Air mass transport pathways into the UTLS and the likely origins of bromine-rich air masses reaching the Southern Hemisphere (SH) lower stratosphere are identified through distributions of in situ measured transport (CO and N­­2O) and air mass lag-time (SF6) tracers as well as Lagrangian transport modelling. Additionally, Brtot measured in the SH is compared with previous measurements observed in the Northern Hemisphere as part of the Wave-driven ISentropic Exchange (WISE) research campaign in fall 2017, as well as the long term trend in stratospheric bromine.
River plastic during floods: Amplified mobilization, limited river-scale dispersion
Authors: van Emmerik Tim , Frings Roy , Schreyers Louise , Hauk Rahel , de Lange Sjoukje , Mellink Yvette
Published: February 2023

Plastic mobilization, transport, and retention dynamics are influenced by hydrological processes and river catchment features (e.g. land-use, vegetation, and river morphology). Increased river discharge has been associated with higher plastic transport rates, although the exact relation between the two can vary over time and space. The precise role of an extreme discharge event on plastic transport is however still unknown. Here, we show that fluvial floods drive floating macroplastic transport and accumulation in river systems. We collected observational evidence during the (return period of 200 years) along the Dutch part of the Meuse. Upstream plastic transport multiplied by a factor of over 100 compared to non-flood conditions (3.3x105 vs 2.3x102), making the Meuse . Over one-third of the annual plastic transport was estimated to occur within the six-day period of extreme discharge (>3,200 m3/s). Towards the river mouth, plastic transport during the flood decreased by 90%, suggesting that the Plastic transport and accumulation on the riverbanks decreased significantly along the river, corroborating the river's function as a plastic reservoir, rather than conduit for plastic towards the ocean. We demonstrate the crucial role of floods as drivers of plastic transport and accumulation in river systems. Floods amplify the mobilization of plastics, but the effects are local and the river-scale dispersion is limited. We anticipate that our findings serve as a starting point for improving global estimates of river plastic transport, retention, and export into the sea. Moreover, our results provide essential insights for future large-scale and long-term quantitative assessments of river plastic pollution. Reliable observations and a fundamental understanding of plastic transport are key to designing effective prevention and reduction strategies. Link to preprintTim van Emmerik, Roy Frings, Louise Schreyers et al. River plastic during floods: Amplified mobilization, limited river-scale dispersion, 08 August 2022, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-1909246/v1]
The Four-Wavelength Photoacoustic Aerosol Absorption Spectrometer PAAS-4λ
Authors: Schnaiter Martin , Linke Claudia , Asmi Eija , Servomaa Henri , Hyvärinen Antti-Pekka , Ohata Sho , Kondo Yutaka , Järvinen Emma
Published: February 2023

Light absorbing particulate emissions, known as black carbon (BC) or brown carbon (BrC), are major contributors to the atmospheric aerosol and have a significant impact on climate forcing. The spectral light absorption coefficient of these particles, which is essential for understanding their impact on the climate, can vary greatly depending on the combustion process and atmospheric aging, particularly in the Arctic where concentrations of BC and BrC are low but the climate is sensitive to changes in the atmospheric aerosol. Traditional filter-based methods for characterizing light absorbing aerosol can be prone to errors in environments where the relationship between particle light scattering and absorption is high due to cross-sensitivity to co-deposited light scattering particles. The photoacoustic absorption spectroscopy (PAS) method is less sensitive to particle light scattering and has a high measurement precision and accuracy, but is not widely used for long-term monitoring due to ist assumed lack of sensitivity and robustness.The Photoacoustic Aerosol Absorption Spectrometer PAAS-4λ has been developed for use in unattended air quality monitoring stations and utilizes four wavelengths coupled to a single acoustic resonator in a compact and robust design. It has a low detection limit of below 0.1 Mm-1 and has been calibrated in the laboratory using NO2/air mixtures and Nigrosin aerosol. The PAAS-4λ has been validated at an air quality monitoring station in the European Arctic and its performance during 12 months of deployment is presented. Comparisons with filter-based photometers demonstrate the capabilities and value of the PAAS-4λ for both long-term monitoring and the validation of filter-based instruments.
Assessing the fate of polycondensed aromatic natural organic matter (NOM) in a high-alpine aquatic system
Authors: Maurischat Philipp , Seidel Michael , Donnerhack Oliver , Guggenberger Georg
Published: February 2023

With the Anthropocene, thermogenic organic carbon, also known as black carbon (BC) is increasingly introduced to ecosystems worldwide. BC is formed by incomplete combustion or pyrolysis of fossil fuels, at wildfires or by the intentional burning of biomass, emitted to the atmosphere and hydrosphere or remaining in the bio-/pedosphere. With its high molecular proportion of elemental carbon, BC is regraded to be protected from fast microbial degradation by its inherent molecular properties. In aquatic systems, BC is partly sedimented or buried when reaching endorheic lakes or the ocean, where it is withdrawn from the carbon cycle. The biogeochemical implications of BC or its degradation products in aquatic systems have therefore not received much attention. Especially in sensitive oligotrophic alpine systems, such as the treeless Tibetan Nam Co catchment, part of the biggest connected alpine pasture system in the world, which is exposed to increasing anthropogenic pressure, any nutrient and carbon surplus can threaten the ecological status.This was studied by an ultra-high resolution mass spectrometry approach that identifies several thousands of molecular formulae in dissolved organic matter (DOM). Including polycondensed aromatics (pcAro) that are considered to include thermogenic DOM.Incubation experiments of water samples indicated that pcAro DOM was transformed by microbes to a comparable degree such as other natural organic matter (NOM) in the samples, removing pcAro DOM by defunctionalization or metabolization. In the environmental samples we found that pcAro DOM discharged to the endorheic Nam Co Lake was transformed by photodegradation along with other aromatic compounds. For DOM of streams and the lake of the high-alpine Nam Co watershed, most pcAro is likely of local origin, i.e. derived from burning of yak faeces by pastoralist households. This pcAro formed from cellulose-rich and lignin-poor Cyperaceae fodder is chemically distinct from low-land natural biomass, usually including the burning of wood.Thus pcAro DOM appeared to be a more viable part of the carbon cycle than previously assumed. Our data support the hypothesis that the fate of polycondensed aromatic DOM depends on several environmental factors, such as catchment characteristics, water opacity, solar irradiation and actual light penetration into the water column, as well as on the carbon source, driving the molecular composition of thermogenic NOM. 
Understanding Regional Sea Level Rise Acceleration Along the North American Eastern Seaboard
Authors: Schoenwald Victoria , Kirtman Ben
Published: February 2023

The East Coast of North America has experienced rates of sea level rise (SLR) five times larger than the global average. This steep increase in SLR contributed to a higher frequency of coastal flooding events along the southeastern seaboard and the worst nuisance flooding event in Miami, FL during the last 20 years. Using tide gauge data from several stations, empirical mode decomposition (EMD) was used to understand sea level variability along the East Coast of the U.S., and its connectivity to atmospheric and oceanic circulation and thermosteric effects. This is a unique approach in identifying the “in phase” sea level variability and how it relates to the atmosphere and the ocean on varying timescales. The EMD modes were also used to understand the “out of phase” components of sea level variability such as the “hot spot” of SLR between Cape Hatteras, NC and Key West, FL where sea levels increased at rates of 25.5mm/year compared to a global average of 4.5 mm/year. Similar techniques were then applied to climate model simulations using sea surface height at coastal locations as proxies for the tide gauge data. The EMD approach was applied at both ocean eddy parameterized and ocean eddy resolving scales. The goal was to determine if the natural variability in the models have similar characteristics to the observational estimates. And, to assess whether the modes associated with the trend in observations have appropriate analogues to the model simulations. By comparing pre-industrial simulations with historical simulations, we will be assessing whether a changing climate affects the natural variability.
Improving the quantification of building energy savings through temperature-sensitivity analysis
Authors: Labuhn Inga , Deroubaix Adrien
Published: February 2023

Buildings are responsible for a significant proportion of total energy consumption and therefore represent an important target for energy savings. Their consumption is strongly temperature-dependent, as it is dominated by the heating and cooling demand to ensure thermal comfort inside.To quantify the energy savings of a building over time (for example after renovation or with lowered indoor temperatures), it is necessary to remove the influence of meteorology on energy consumption and determine the part that is independent of weather, i.e. related to the building properties and its use. Current methodologies use daily energy demand proxies (degree-days) with fixed temperature thresholds for heating and cooling. However, hourly energy consumption is increasingly monitored by smart meters, and high-quality meteorological reanalysis data are available globally, giving access to a finer temporal scale on which variations in both outside temperature and building use are expected.Here we present a case study using 10 years of hourly meteorological data and energy consumption data from a university campus in Germany. We analyze the meteorology-dependent energy consumption including its sub-daily variations. We investigate the differences in energy savings quantification depending on the time step used. The detailed knowledge of energy consumption patterns and their temperature sensitivity that we obtain also provides the basis for identifying potential future energy savings through retrofits and changes in user behavior.
Effects of steering of tracked combine harvester on shear damage of paddy field soil
Authors: Ding Zhao , Xin Ping , Su Zhan
Published: February 2023

During steering, the slide and slip of the tracked combine harvester relative to the ground will cause serious shear damage to the soil and reduce the steering performance of the vehicle. The pivot steering mode of the combine harvester is gradually applied because of its significantly improved steering stability and efficiency compared to the traditional unilateral braking steering mode. However, the effects of the steering mode of the combine harvester on shear damage of soil remain unclear. In this study, a steering resisting torque model is established by considering the slide and slip condition of tracked vehicles. Meanwhile, the influence of slide and slip of the track on shear damage of soil is theoretically analyzed, and the steering tests of unilateral braking and pivot steering modes are conducted in the paddy field soil with different moisture contents using the tracked combine harvester. Besides, by testing the trajectory outline after steering, the soil shear area (disturbance area of the track) and shear deformation (the maximum elevated height and maximum shearing depth of soil) of soil are used as indicators to compare the shear damage to soil in the two steering modes. The results indicate that the slide and slip of the track coefficients are inversely proportional to the shear deformation of the soil, but they have no significant influence on the shear area of the soil. The combine harvester working in the pivot steering mode reduces the shear area of soil by about 50% compared with that of unilateral braking steering. When the track slip coefficient is smaller than the critical slip coefficient at this condition, the soil shear deformation caused by unilateral braking steering is larger than that of pivot steering. This research result provides some references for selecting the steering mode of the tracked combine harvester in different soil conditions.
MS-GWaM - A three dimensional transient parameterization for internal gravity waves in atmospheric models
Authors: Voelker Georg Sebastian , Kim Young-Ha , Bölöni Gergely , Zängl Günther , Achatz Ulrich
Published: February 2023

Internal gravity waves (IGWs) are important distributors of energy and momentum in a stratified atmosphere. While most IGWs are presumably excited at lower altitudes their effects are most important between the upper troposphere and the mesopause (~85km). During propagating - both in the vertical and the horizontal - nonlinear IGWs can exert a wave drag on the large-scale winds, interact with the large-scale potential temperature, and influence transport and mixing of atmospheric constituents such as aerosols or greenhouse gases.In state-of-the art weather and climate prediction models subgrid-scale IGWs are typically parameterized neglecting both the horizontal wave propagation (single-column assumption), the transient wave behavior including its effect on wave-mean-flow interactions (steady-state assumption) as well as time dependent wave generation. While being computationally efficient the missing physics, however, may lead to model errors and inaccurate predictions under varying boundary conditions. The potential importance of the horizontal wave propagation and wave transience has been shown in various theoretical, numerical and experimental studies.The transient Multi Scale Gravity Wave Model (MS-GWaM) - implemented in the high-top model UA-ICON - aims to improve these shortcomings by allowing for transient and three dimensional wave propagation. The parameterization is based on a multi scale WKBJ analysis of the compressible atmosphere and includes various non-orographic wave sources, non-dissipative wave-mean-flow interactions as well as wave breaking. Internally, the parameterized gravity waves are treated as Lagrangian volumes with the dynamics prescribed by the well known gravity wave modulation equations. A suitable projection method of wave properties onto the unstructured model grid facilitates the calculation of wind and temperature tendencies. What is more, an efficient parallelization of the ray-tracing scheme allows for simulations in reasonable computation times, being much faster than corresponding wave resolving runs.While satisfactorily reproducing the observed zonal-mean wind and potential temperature climatology the model results reveal new insight into the detail of the role of IGWs in the atmosphere. In particular, probability density functions of wave momentum fluxes exhibit the typical observed long tails (i.e. wave intermittency) which cannot be reproduced with steady-state parameterizations. Moreover, the three dimensional distribution of wave momentum and wave action fluxes differ greatly when relaxing the single-column assumption. As an example the well known three dimensional refraction of IGWs into polar jets can be shown.
Studying the effect of moving sandy bedforms on the infiltration behavior of microplastic particles
Authors: Alhusban Zaid , rovelli lorenzo , Lorke Andreas
Published: February 2023

When it comes to plastic manufacturing worldwide, more than half of what is produced gets dumped into the world's oceans and rivers. The rivers are the primary pathways for plastics to reach the seas. The infiltration behavior of plastic particles into mobile sediment beds (coarse sand) with median diameters (d50) between 0.4 and 0.8 mm was studied using flume experiments with varying plastic particle parameters (such as density and size) under a variety of controlled hydraulic settings.The results are thought to be very useful for improving our understanding of and research into how microplastic particles with different characteristics infiltrate into rivers and streams (in mobile beds) with different bedload rates and stay there. The findings showed that microplastic particles were present in both the stationary and mobile sediment layers of the moving sandy bedforms. The number of particles that infiltrate into the sediment is influenced by particle sizes, densities, and bedform characteristics. In general, it was found that the distributions of microplastic particles of different types and sizes in migrating sandy sediment were heterogeneous, although certain trends could be seen, such as a reduction in infiltration rate and average infiltration depth with increasing bedform celerity. Higher infiltration depths and infiltration percentages are also seen for denser and smaller particles. Additionally, the ratio of infiltrated particles in stationary layers of bedforms to total infiltrated (%) decreases as bedform celerity increases. Using the project's findings, future research and numerical modeling studies on plastic particles' accumulation, distribution, and pathways will be able to inform better decisions about how to clean up future microplastic sediment pollution, as well. 
ECMWF-OpenIFS Climate Sensitivity to Horizontal Resolution and Time Step
Authors: Savita Abhishek , Kjellsson Joakim , Pilch Kedzierski Robin , Park Wonsun , Latif Mojib , Wahl Sebastian
Published: February 2023

We explored the sensitivity of the atmosphere general circulation model OpenIFS to horizontal resolution and time step. We conducted a series of experiments at different horizontal resolutions (i.e., 100, 50, and 25 km) while maintaining the same time step (i.e., 15 minutes), and using different time steps (i.e., 60, 30 and 15 minutes) at 100 km horizontal resolution. We find that the zonal wind bias over the Southern Ocean has significantly reduces at high horizontal resolution (i.e., 25 km), and that this improvement is evident too when using a coarse resolution model with smaller time step (i.e., 15 min and 100 km horizontal resolution). There is also evidence of improvements in the mid-latitude westerly jet in the Northern Hemisphere too, which is also sensitive to both model time step and horizontal resolution. We have also found that the biases in wave speed and wave amplitude reduce when we shorten the model time step or increase the model horizontal resolution. Therefore, it is clear that the improvement in the highest horizontal resolution (i.e., 25 km) simulation is a combination of both the enhanced horizontal resolution and shorter time step. We speculate that the improvement in the surface zonal wind bias in the coarse resolution with shorter time step (i.e., 15 min and 100 km horizontal resolution) simulation is mostly due to shallow convection that is intensified at shorter time step. In addition, we have also noticed improvements in the surface-air temperature when a high resolution and a smaller time step; however, the precipitation bias is independent of the model’s horizontal resolution and time step.We propose based on OpenIFS that by reducing the time step in a coarse resolution atmospheric model (at least in OpenIFS), one can alleviate the surface-wind biases in the extratropics that is important for e.g., climate modeling in the Southern Ocean sector.
Seismic events relocation and velocity models for the Atacama seismic gap at Central-Northern Chile (24.5-29°S)
Authors: Hernádez-Soto Nicolás , Miller Matthew , González-Vidal Diego , Moreno Marcos , Lange Dietrich
Published: February 2023

Information about seismic velocities and the seismicity distribution in subduction zones can reveal the effect physical properties have over large ruptures. The ANILLO (Y6) Seismic Network spans between 24.5°S - 29°S in Chile. Composed of 104 seismic stations, it was operative between 2020 and 2022. Deep Learning algorithms (EQTransformer) enable the identification of more than 30,000 seismic events during the eighteen months of operation time, in an area with an important lack of moderate-to-large events during the last century since the nucleation of the 1922 M8.5 Atacama earthquake. Using a subset of events with a good spatial distribution, low residuals, and many P- and S-arrivals, we obtained a well-distributed subcatalog of 1000 earthquakes, corresponding to 26,570 P- and 22,109 S-wave arrival times. Using VELEST for the selected events, inverting for station corrections, we computed a novel 1-D velocity model representative of this region by minimizing the subset residuals. This enabled us to relocate the complete catalog, reducing both the residuals and the location errors of all events. Starting from this 1-D velocity model, staggered tomographic inversions were performed using SIMUL2000, simultaneously inverting for seismic velocity models and hypocentral parameters according to the iterative damped least squares method. The complexity in the tomographic model was gradually increased, from 2-D to ultimately a 3-D fine model with low node separation. Preliminary results show that earthquake arrival times picked using Deep Learning algorithms can provide an exceptional database for tomographic studies, with residuals similar to human-picked databases. We obtain a good resolution underneath the seismic network in the forearc, with a reduced resolution and smearing in off-shore areas where location uncertainties, especially in the vertical direction, are greater. We suggest that the incorporation of OBS data would significantly improve the off-shore model. We observe an east-dipping, high Vp velocity structure subducting in the expected slab position, in which the relocated seismic events, with a low vertical location error, follow the slab geometry in distinct seismicity bands. Additionally, observed shallow seismicity could be related to crustal faults, mining activity, or even dehydration processes near the slab's upper surface. The event locations and velocity structure are interpreted in terms of the geological and geophysical characteristics of the subduction zone at these latitudes that may influence the behavior of large megathrust earthquakes.