bluuebunny/crossref_metadata_2025 huggingface dataset:
Meteor phenomena in the atmosphere of Venus
Authors: Christou Apostolos , Gritsevich Maria
Published: February 2023

Meteor astronomy employs the atmosphere of the Earth as a large area detector for 0.01-1000 mm meteoroids [1]. Monitoring the atmospheres of other planets for meteor activity offers the opportunity to study the parent bodies of as-yet-undetected meteor showers, test ablation models under non-terrestrial conditions and allow spacecraft operators to mitigate the risk of meteoroid impact damage [2]. By adjusting existing techniques to simulate meteoroid ablation in a Venus-like atmosphere [3-8], we show that Venusian meteors are generally brighter but shorter-lived than terrestrial meteors and ablate at a higher altitude, in a predominantly clear region of the atmosphere. These simulations are complemented with a list of cometary bodies and known meteoroid streams that we consider to be prime candidates for producing significant meteor activity at Venus [9,10]. Such predictions may be used in developing future observational campaigns to be carried out from Earth or from Venus orbit.References: [1] Jenniskens, P. (2006) Meteor Showers and their Parent Comets, Cambridge University Press, Cambridge. [2] Christou A. A. et al (2019) In: Meteoroids: Sources of Meteors on Earth and Beyond, Cambridge University Press, p.119-135. [3] Christou A. A. (2004) Icarus 168, 23-33 [4] McAuliffe, J. P., Christou, A. A. (2006) Icarus 180, 8-22 [5] Gritsevich M., Koschny D. (2011) Icarus 212, 877-884 [6] Bouquet A. et al (2012) Planet. Space Sci. 103, 238-249 [7] Gritsevich, M. I. (2009) Adv. Space Res. 44, 323–334 [8] Lyytinen, E., Gritsevich, M. (2016) Planet. Space Sci. 120, 35-42 [9] Christou A. A. (2010) MNRAS 402, 2759-2770 [10] Christou, A. A., Vaubaillon, J. (2011) In: Proc. Meteoroids Conf, NASA/CP-2011-216469, p.2
Assessing the impact of climate change scenario for simulating nonstationary rainfall intensity and duration
Authors: Salem Ali , Abduljaleel Yasir
Published: February 2023

The intensity and frequency of extreme storms have been increasing over time due to climate change, challenging sustainable stormwater management. This study examines the impacts of climate change on the precipitation patterns and extremes across the Cedar River Watershed in the Pacific Northwest under the Shared Socio-economic Scenario (SSP-585) obtained from CMIP6 models. Two global climate models (GCMs), namely MIROC6 and CMCC-ESM2, are considered in this study. Prior to generating future extreme storms for the selected GCMs and scenarios, the GCM simulated precipitation data was bias corrected relative to in-situ daily precipitation data. Precipitation data was bias corrected using three different statistical methods (please Named three method); among those Equidistant Quantile Mapping performed best. Bias corrected precipitation from the MIROC6 showed better performance compared to the CMCC-ESM2 in reproducing the observed precipitation statistics. Finally, the bias-corrected precipitation data from MIROC6 was used to develop non-stationary Intensity-Duration-Frequency curves (IDF) to identify the extreme storm events and their return periods. The results indicate that the storm intensities increase (ranging from 2.5% to 30%) over the future periods for all selected return periods, with relatively larger increase for higher return periods i.e., 50-year and 100-year storms. Further, we use the bias corrected precipitation projections and generate mean monthly perception maps of the Cedar River Watershed for the periods of 2020–2039 and 2040–2059. 
New insights into the rheology of a normal fault: the Mw6.1 2009 L’Aquila case study
Authors: Fonzetti Rossella , Valoroso Luisa , De Gori Pasquale , Chiarabba Claudio
Published: February 2023

The study of seismogenic faults is one of the most interesting topics in seismology.  Obtaining a more detailed image of the fault zone structure and of its properties (e.g., fluid content, permeability, lithology, rheology) is fundamental to understand how seismic ruptures originate, propagate and arrest and to study the triggering processes.  The 2009 Mw 6.1 L’Aquila seismic sequence is a perfect case study to reach this goal, thanks to the huge amount of multidisciplinary data available. In this study, we reprocess the high-precision large earthquake catalog available for the L’Aquila seismic sequence, focusing on the main (Paganica) seismogenic fault (about 20,000 earthquakes occurring between January-December 2009). We used cross-correlation and double-difference tomography methods to compute high-resolution (2.5 x 2.5 x 2 km grid spacing) Vp and Vp/Vs models along the fault plane. High-resolution Vp and Vp/Vs models give insights into the rheology of the Paganica fault, suggesting new ideas on earthquake generation, propagation and arrest.  
High-resolution upper crustal structure from OBH data at the TAG Hydrothermal Field, 26°N on the Mid-Atlantic Ridge
Authors: Lai Szu-Ying , Bayrakci Gaye , Murton Bramley , Minshull Tim
Published: February 2023

The Trans-Atlantic Geotraverse (TAG) segment at 26°N on the Mid Atlantic Ridge (MAR) is notable for hosting hydrothermal mounds and seafloor massive sulphide deposits. At the slow-spreading MAR, detachment faulting plays an important role in controlling the seafloor morphology. In this study, we investigate the seismic velocity in the upper crust at a finer scale than previously possible, and its relationship to fault structures.We used short-offset ocean bottom hydrophone (OBH) data collected during the Meteor 127 cruise in 2016. The survey was designed mainly to study the hydrothermal mounds. We chose a NW-SE trending, 11-km long wide-angle seismic profile that crosses a detachment breakaway identified from AUV bathymetry and seismic reflection profiles. The source was a G-gun array of 760 c. inch towed at 6 m depth. The shot spacing was 12 s (15-20 m) with four OBHs at 1.3 km spacing.A two-dimensional P-wave velocity model was generated by first-arrival travel-time tomography using the TOMO2D code. We used as our starting model the average 1D velocity depth function of a slice along our profile through Zhao et al’ s (2012) three-dimensional velocity model. Our final tomographic model reveals crustal velocities from 3.4 km/s to 5 km/s for the upper 600 m below seabed. Most of the profile lies beneath the eastern valley wall, where a corrugated detachment surface crops out. Beneath the detachment surface in our profile, we observed an increased velocity of 6.5 km/s at 1.5 km below seabed. Our velocity model suggests that the west-dipping normal fault exhumes lower crust of velocity up to 6.5 km/s.
An additional plasma density peak at poleward of the equatorial ionization anomaly crests observed by Swarm
Authors: Xiong Chao , Huang Yuyang
Published: February 2023

The equatorial ionization anomaly (EIA) is one of the most important phenomena at equatorial and low latitudes, which is caused by the daytime eastward electric field via E×B effect. The well-developed EIA at dayside is thought to be a quite large structure with two crests extending to ±15° magnetic latitude, and the plasma density distributes quite smooth along the magnetic fluxtube. However, an additional density peak at poleward of the EIA crests is sometimes observed from the high-resolution plasma density measurements of Swarm. The additional peak is observed at the poleward of EIA crest only in the summer hemisphere, and shows a local time preference between 09:00 and 24:00. From a global view, the additional peak has relatively large occurrence at the norther hemisphere in the pacific longitudes. From the perspective of constellation, the Swarm B can revisit the same longitude of Swarm A/C, though with a certain time day. The delay time gradually increases from a few minutes to a few hours. By comparing the location of the additional peak observed by Swarm B and Swarm A/C, we found the peak keeps at a rather constant latitude irrespective of the delay time between Swarm satellites. Possible drivers for causing such additional peak have been further discussed.
Appinite complexes, granitoid batholiths and crustal growth: a conceptual model
Authors: Murphy J. Brendan , Collins William J. , Archibald Donnelly B.
Published: February 2023

Appinites are a suite of plutonic rocks, ranging from ultramafic to felsic in composition, that are characterized by idiomorphic hornblende as the dominant mafic mineral in all lithologies and by spectacularly diverse textures, including planar and linear magmatic fabrics, mafic pegmatites and widespread evidence of mingling between mafic and felsic compositions. These features suggest crystallization from anomalously water-rich magma which, according to limited isotopic studies, has both mantle and meteoric components.Appinites typically occur as small (~2 km diameter) complexes emplaced along the periphery of granitoid plutons and commonly adjacent to major deep crustal faults, which they preferentially exploit during their ascent. Several studies emphasize the relationship between intrusion of appinites, granitoid plutonism and termination of subduction. However, recent geochronological data suggest a more long-lived genetic relationship between appinites and granitoid magma generation and subduction.Appinites may represent aliquots of hydrous basaltic magma derived from variably fractionated mafic underplates that were originally emplaced during protracted subduction adjacent to the MOHO, triggering generation of voluminous granitoid magmas by partial melting in the overlying MASH zone. The hydrous mafic magmas from this underplate may have ascended, accumulated, and differentiated at mid-to-upper crustal levels (ca. 3-6 kbar, 15 km depth) and crystallized under water-saturated conditions.  The granitoid magmas were emplaced in pulses when transient stresses activated favourably oriented structures which became conduits for magma transport. The ascent of late mafic magmas, however, is impeded by the rheological barriers created by the structurally overlying granitoid magma bodies. Magmas that form appinite complexes evaded those rheological barriers because they preferentially exploited the deep crustal faults that bounded the plutonic system. In this scenario, appinite complexes may be a direct connection to the mafic underplate and so its most mafic components may provide insights into processes that generate granitoid batholiths and, more generally, into crustal growth in arc systems. 
Climatological assessment of the vertically resolved optical aerosol properties by lidar measurements and their influence on radiative budget over the last two decades at UPC Barcelona
Authors: Lolli Simone , Comeron Adolfo , Gíl-Diaz Cristina , Landi Tony , Munoz-Porcar Constantin , Oliveira Daniel , Rodriguez-Gomez Alejandro , Sïcard Michael , Alastuey Andrés , Querol Xavier , Reche Cristina
Published: February 2023

In the last two decades, several scientific studies have highlighted the adverse effects, primarily on population health, transportation, and climate, of urban atmospheric particulate due to anthropogenic emissions. For these reasons, aerosols have been monitored through both, remote sensing and in-situ observation platforms, also to establish if the reduction emission policies implemented at the government level have had positive outcomes. In this study, for the first time, we assess how the vertically resolved properties of the atmospheric particulate have changed and consequently their radiative effect during the last twenty years in Barcelona, Spain, one of the largest metropolitan areas of the Mediterranean basin. This study is carried out in the frame of the ACTRIS project through synergy between lidar measurements and the meteorological variables, e.g. wind, temperature, and humidity at the surface. This research, thanks to twenty-year measurements, can shed some light on the meteorological processes and conditions that can lead to haze formation and can help decision-makers to adopt mitigation strategies to preserve large marine Mediterranean metropolitan regions.
Hydrological performance of soil and vegetation covers impact in mine rehabilitation: results of a preliminary modelling study
Authors: Filipović Vilim , Baumgartl Thomas
Published: February 2023

Rehabilitation in the mining context refers to restoring the natural characteristics such as land stability, vegetation, soil functions, biodiversity and hydrological cycle. The main aim of mine rehabilitation is to construct environmentally sustainable landforms and to restore their ecosystem services, either to a site specific stable equilibrium or ideally to its previous state. The objective of this work is to build a predictive and decision making tool using hypothetical modelling to simulate water fluxes for two different scenarios in terms of different soil cover depth including vegetation (grass). Hypothetical hydrological modelling was performed using the HYDRUS-1D with one-dimension water flow modelling based on the Richards equation and hydraulic functions of van Genuchten-Mualem model. The soil and coal hydraulic parameters were derived from laboratory tests using the extended evaporation method. Water flux modelling was performed for 2021 using the climatic data from Latrobe Valley (Victoria, Australia) meteorological station, where the coal and soil samples were collected. Two scenarios were selected which varied in the depth of soil cover and coal layer, both with grass vegetation on top of the soil columns. The first scenario (S1) had 50 cm of soil cover, while the second scenario (S2) had 100 cm of soil cover on top of coal material, respectively. Modelling results revealed that soil water content and fluxes were directly reflecting the precipitation pattern and the most limiting factor in downward water flow was the low permeability of the coal layer. The hydraulic parameters for coal show large water retention capacity at very low hydraulic conductivity. The shallower soil cover in the S1 scenario resulted in higher soil water content during the period of intense rainfall and resulted in larger and faster initiation of surface runoff. The thicker soil cover layer resulted in larger infiltration rate and root water uptake which was however limited when the soil was fully saturated in both scenarios. Interestingly, very similar bottom flux in both scenarios even with two different coal layer depth (i.e., 30 cm vs 80 cm) were recorded. Water balance results indicate increase in potential of storing water in the S1 scenario which has a thicker coal layer due to its high water retention capacity. However, at this point it is not clear to what extent stored water from coal can be available for plants. Beside valuable research insights in terms of soil cover design, hypothetical modelling will assist in preventing experimental design flaws and providing a more efficient, robust controlled experiment performed in a next study phase.
The future of urban soil policy in Cork, Ireland
Authors: Binner Hannah , Sullivan Timothy , McNamara Maria
Published: February 2023

Urban soils are prone to accumulating metals over time. This is caused by the proximity of urban soils to roads and industry, among other sources. In Europe, many urban areas show metal enrichment linked to anthropogenic activity. The public are in contact with urban soils on a regular basis. This potentially has adverse effects on human health, especially in locations with enrichment of metals that are systemic toxicants, such as As, Cd, Cr, Hg and Pb. Despite this, most European countries lack dedicated policy on urban soils. In Ireland, data on urban soil metals exist for only two urban centres (Dublin and Galway), both of which show anthropogenic enrichment of metals. Cork city is an ideal target for study of urban soil metals because its history includes over 200 years of industrial development, and its urban parks include former brownfield and industrial sites. Here, we measured concentrations of urban soil metals for ten sites in Cork city using a portable XRF (X-ray fluorescence) analyser. In addition, two sites were selected for ICP-MS analysis in order to provide an independent test of the accuracy of the XRF data.  Our results show that at all ten Cork sites, Pb is highly enriched in soils, with concentrations up to ten times greater than natural background levels. Fe, Mn and Zn are moderately enriched at each of the ten sites, with concentrations typically between two to five times natural background levels. Metal concentrations are systematically higher at sites in the city centre than suburban sites. These patterns of metal enrichment are similar to those seen in urban soils elsewhere in Europe. Future EU policy is essential for the assessment of urban soils and for the remediation of contaminated sites. This research has already helped to inform the Geological Survey of Ireland and the Government of Ireland Department of the Environment, Climate and Communications to help facilitate the implementation of data-driven legislation. It is anticipated that a relevant soil policy will come into effect in the coming years, which will aid the assessment and remediation of contaminated urban soils across Ireland. 
Juno observations of Io
Authors: Mura Alessandro , Tosi Federico , Zamboni Francesca , Hansen Candice , Lopes Rosaly M. , Becker Heidi N. , Rathbun Julie , Adriani Alberto , Plainaki Christina , Sindoni Giuseppe , Sordini Roberto
Published: February 2023

NASA’s Juno mission has been observing the Jovian aurorae since 2016 from a polar, highly elliptical orbit.Although not in the main scientific objectives, Juno took images and spectra of the Galilean moons from avery favourable position, using some of the cameras on board: JIRAM, JunoCam and SRU. In particular, TheJovian Infrared Auroral Mapper (JIRAM) is a dual-band imager and spectrometer. The imager channel is asingle detector with 2D capability and with 2 different filters (L band, from 3.3 to 3.6 µm; M band, from 4.5to 5 µm); the spectrometer is a 1-D detector with a spectral resolution of 9 nm in the range 2 - 5 µm. Thepixel angular resolution (0.01°) is fine enough for imaging the moons from the polar, highly elliptical orbit ofJuno; the spatial resolution at the surface of the moons varies along the s/c distance and is of the order of100 km/pixel or even finer. Here we present JIRAM’s images and spectra of Io aftersix years of Juno mission, together with JunoCam and SRU images of Io. On Io, these observationscharacterize the location and possible morphology, and some temperatures, of the volcanic thermalsources; the identification and distribution of SO 2 , the possible identification of CO 2 and other materials. Recent Juno flybys, at distance down to 50'000 km, allows unprecedented imaging of the moon with resolution of about 10 km.This allows reconstructing the morphology of hot spots, and a better mapping of their distribution, in location and emitted power.
Mobility of potentially toxic metals and metalloids in soils impacted by tailings with distinct oxidation stages.
Authors: Armienta M. Aurora , Zúñiga-Vázquez Diana , Cruz Olivia , Aguayo Alejandra , Reséndiz Isabel
Published: February 2023

To develop effective methods to solve pollution problems caused by mine tailings in soils, the environmental availability of potentially toxic metals and metalloids (PTMM) must be adequately assessed. This involves detailed chemical and mineralogical studies in the tailing piles and impacted soils. Research carried out in tailings with various oxidation degrees in a semi-arid historical Mexican mining zone revealed differences in the mobility of As, Cd, Pb, Zn, Cu, Mn in the respective soils that were impacted by rain wash-off, aerial transport, and acid mine drainage. Sequential extractions showed that most of the PTMM were in the Mn and Fe oxyhydroxides fractions in soils impacted by oxidized tailings while a predominance in the proportion present in the organic and sulfide fractions was determined in those receiving the influence of less oxidized deposits. Zn and Cd presented the highest geoavailability in oxidized tailings. Although sulfide minerals oxidation as pyrite and arsenopyrite produce acid mine drainage, the abundance of calcite in the geology of the area increases the pH and promotes the formation of iron oxyhydroxides that retain part of the PTMM through sorption. On the other hand, although As has low mobility in soils (less than 3 % in the soluble fraction), its high total concentrations (up to 51,500 mg/kg), implies also an environmental hazard. A modification in the climate conditions of the area, such as heavy storms that may be promoted by climate change, would increase the tailings transport through wash-off,  in addition to the mobilization and soil infiltration mainly of the most geoavailable elements by dissolution.
Capturing SUbsurface PREferential transport processes in agricultural HILLslope soils: SUPREHILL CZO
Authors: Filipović Lana , Krevh Vedran , Defterdarović Jasmina , Kovač Zoran , Bogunović Igor , Mustać Ivan , Beck-Broichsitter Steffen , Gerke Horst H. , Groh Jannis , Kodešová Radka , Klement Aleš , Dusek Jaromir , He Hailong , Brunetti Giuseppe , Baumgartl Thomas , Filipović Vilim
Published: February 2023

Agricultural hillslopes present particular challenges for estimating vadose zone dynamics due to a variety of processes, such as surface runoff, vertical flow, erosion, subsurface preferential flow affected by soil structure and layering, non-linear chemical behaviour, evapotranspiration, etc. To investigate these processes and complexity, the SUPREHILL critical zone observatory (CZO) was started in 2020, at vineyard hillslope site in Croatia. The observatory is extensively equipped for the soil-water regime and agrochemical fluxes monitoring, and includes an extensive sensor network, lysimeters (weighing and passive wick), suction probes, surface and subsurface flow and precipitation collection instruments. The main objective of the SUPREHILL observatory is to quantify subsurface lateral and local scale preferential flow processes. Local-scale nonlinear processes in eroded agricultural hillslope sites have large significance on water and solute behaviour within the critical zone and thus need to be researched in depth using combined methods and various approaches. First results from the sensor and lysimeter network, soil-water regime monitoring, isotope analysis, and agrochemical concentrations in 2021 supported the hypothesis of the observatory, that the subsurface flow plays a relevant part in the hillslope soil-water dynamics. In the wick lysimeter network, although the highest cumulative outflow values were found at the hilltop, the highest individual measurements were found at the footslope. During high-intensity rainfall events, there were differences in weighing lysimeters, possibly related to subsurface lateral flow. Based on the isotope analysis, wick lysimeters exhibit a greater variation of d-excess values than suction probes. Agrochemical fluxes confirmed the sloping effect on their transport in soil and demonstrated the favourability of Cu transport by subsurface flow. Using the comprehensive database presented herein, future analyses of this hypothesis will be carried out in more detail using model-based analyses.  
Interaction between ice sheet instability and sea surface characteristics in the Labrador Sea during the last 50 ka
Authors: You Defang , Stein Ruediger , Fahl Kirsten
Published: February 2023

The study on the decay of ice sheets in the past provides important insights into the interaction between ice sheet behaviours and ocean characteristics, especially under a sustained warming climate. On the one hand, the ice sheet may affect the ocean environment; on the other hand, changes in sea surface conditions may affect the instability of the ice sheets. However, interactions between ice sheet dynamics and sea surface characteristics are still not fully understood. Thus, studies of carefully selected sediment cores representing both ice-sheet and ocean characteristics can help to better predict changes in ice sheets in the future. Here, we show sedimentary records from the eastern Labrador Sea, proximal to the Laurentide Ice Sheet (LIS) and the Greenland Ice Sheet (GrIS), representing the last 50 ka, i.e., the last glacial-deglacial-Holocene period. Our XRF and biomarker data document the outstanding collapse of the LIS/iceberg discharge during Heinrich Events (i.e., HE5, HE4, HE2, and HE1) and the occurrence of meltwater plumes from the LIS and GrIS during the deglaciation. Such meltwater discharge has caused surface water freshening in the Labrador Sea and, consequently, decreased sea surface temperatures and decreased primary productivity. Enhanced Irminger Current inflow might have triggered the retreat of ice sheets/meltwater discharge, as shown in our planktic foraminifera records. In contrast to dominantly relatively low primary productivity during the glacial period, both higher sea ice algae and phytoplankton production occurred during the Last Glacial Maximum (LGM), probably caused by a polynya in front of the GrIS reaching its maximum extent at that time. During the deglaciation to Holocene time interval, primary productivity shows an increasing trend probably related to decreased meltwater discharge, decreased sea ice extent, and increased insolation. 
Sources of geo-simulation/game (GSG) resources
Authors: Crookall David , Promduangsri Pimnutcha
Published: February 2023

Games have existed almost since the dawn of ‘civilization’.  “The history of games dates to the ancient human past.  Games are an integral part of all cultures and are one of the oldest forms of human social interaction.  Games are formalized expressions of play which allow people to go beyond immediate imagination and direct physical activity.  Common features of games include uncertainty of outcome, agreed upon rules, competition, separate place and time, elements of fiction, elements of chance, prescribed goals and personal enjoyment.” (Wikipedia.)  One of the earliest modern works about games was Huizinga’s (1938 & 1998) Homo Ludens.  The founding work of modern academic gaming is unquestionably Dick Duke’s (1974 & 2014) Gaming: The Future’s Language.Since then, the literature on simulation/gaming (and on crucial debriefing) has exploded.  Dick Duke worked in land planning, and today the gaming literature in areas related to the Earth, the environment, conservation, climate change has exploded.  This is due partly to the increase in massive and wicked problems in those areas, and due partly to the realization that simulation/games are an, and sometimes the only, effective method (or tool) for solving complex problems and for providing guidance in navigating complexity.The result today is that geo-simulation/games GSGs are spread across far flung places – libraries, depositories, institutes, associations and private collections.  The geo-simulation/gamer (practitioner and researcher) looking for material or a method has a hard time.This presentation will outline a few pockets where a relatively high concentration of GSG activity and materials may be found.  It will also unveil a simple database destined for GSGs, in the hope that EGU members will contribute and benefit.
Nighttime concentrations of NO3 and N2O5 in mixed anthropogenic/biogenic air masses during the ACROSS campaign
Authors: Harb Sergio , Cirtog Manuela , Cazaunau Mathieu , Feingesicht Maxime , Michoud Vincent , Landsheere Xavier , Pangui Edouard , Alhajj Moussa Estephanie , Berge Antonin , Cantrell Christopher , Picquet-Varrault Benedicte
Published: February 2023

The nitrate radical (NO3) is mainly formed in the atmosphere through the reaction of nitrogen dioxide (NO2) with ozone (O3). It accumulates at night because during the day its photolysis in sunlight and its rapid reaction with nitric oxide (NO) can rapidly consume it. NO3 radical is a major nighttime atmospheric oxidant of biogenic volatile organic compounds (BVOCs), which represent alone 75 to 90% of global non-methane VOC emissions.Nighttime chemistry between NO3 and BVOCs has received increased attention in the recent literature due to its potential influences on climate, air quality, health and visibility through the formation of many gaseous and particulate secondary pollutants such as organic nitrates, secondary organic aerosol (SOA), ozone and other functionalized products. In several studies conducted in clean forested environments,  NO3 concentrations were found to be very low, mostly below the detection limits (2-6pptv), which can be explained by the low concentrations of precursors (NO2 and O3) and the high reactivity of NO3 with unsaturated BVOCs. However, significant contribution of NO3-BVOC reactions to the secondary pollutants formation in these clean areas have been found.Since NO3 radicals are formed more rapidly in polluted air masses, it is expected that reactions with BVOCs are even more important in mixed atmospheres, i.e. influenced by both biogenic and anthropogenic sources and characterized by relatively high concentrations of both VOCs and NO2. The ACROSS (Atmospheric ChemistRy Of the Suburban foreSt) field campaign was carried out in June and July 2022 in Ile-de-France region and aims, among other objectives, to assess the potential impact of NO3-BVOC nocturnal processes on SOA formation. For this purpose, a newly developed field instrument, called "NOyBox", was deployed on top of a 40-meter tower, which is above the canopy, located at the Rambouillet Forest supersite southwest of Paris. The instrument allows the measurement of NO3 radicals, N2O5 and HONO (IBB-CEAS, Incoherent Broad Band Cavity Enhanced Absorption Spectroscopy), NO2 (CAPS, Cavity Attenuated Phase Shift) and NOy (gold heated converter coupled with a NO chemiluminescence analyzer). Significant concentrations of NO3 and N2O5 were detected on several nights with situations characterized by air masses coming from the direction of Paris, high concentrations of ozone and NO2, and moderate relative humidity levels. Concentrations of these species as well as concentrations of species of interest for NO3 chemistry are presented and the resulting implications on nighttime chemistry are discussed.
MAGIC – The value of the second pair
Authors: Pail Roland , Abrykosov Petro , Science Team the MAGIC
Published: February 2023

The main objective of the joint ESA/NASA Mass-change And Geoscience International Constellation (MAGIC) is to extend the mass transport time series from previous gravity missions such as GRACE and GRACE-Follow on with significantly enhanced accuracy, spatial and temporal resolutions. The concept is based on a joint ESA/NASA Mission Requirements Document (MRD). The first pair of the MAGIC Constellation will be implemented via a Germany-USA fast-paced cooperation to ensure continuity of observations of GRACE-Follow On, with some potential ESA in-kind contributions. The second pair will be implemented via a Europe-USA cooperation with some potential NASA in-kind contributions. The target launch date will be compatible to maintain at least 4 years of combined operations.The current baseline scenario consists of a polar pair (P1) at an altitude of 488 km and an inclination of 89° without ground track control, and an inclined pair (P2) at 397 km and 70° inclination with a 5-day repeat sub-cycle, in order to ensure ground track homogeneity and a constant quality of resulting near-real time service products.In the frame of extensive full-fledged numerical simulations with realistic error assumptions regarding instrument performances and background model errors, the expected performance of the resulting short- to long-term gravity field products is evaluated. In this contribution, the main focus lies on the quantification of the added value of P2 and the relative contributions of P1 and P2 to the combined constellation solution. In particular, the achievable performance for short-term products (daily, 5-day) will be evaluated. In addition, we will analyze and quantify the value of P2 alone over the regions covered by the 70° inclined orbit. From the processing side, using spherical harmonics as base functions, this requires also an adequate treatment of the polar gap areas. Finally, we will match all results against the MRT/MRTD requirements and will evaluate the impact on various fields of science and service applications (continental hydrology, cryosphere, oceans, solid Earth, geodesy).
Engineered soils for recultivation of degraded sites
Authors: Gantar Anja , Zupanc Vesna , Grčman Helena , Zupan Marko
Published: February 2023

The total area of agricultural land in Europe and Slovenia is constantly decreasing, causing the loss of a potential for food production and self-sufficiency capacity. In addition to limiting soil sealing, one of the main objectives of the EU Soil Strategy for 2030 involves recultivating degraded sites, which requires appropriate materials, in particular for fertile, top layers.Due to the complexity of the restoration process of agricultural land, the ability of the restored areas to provide full or any scope of ecosystem services as expected depends on several factors. What the opencast mines have in common is the removal of the top, fertile part of the soil in the exercising of mining rights. The availability of fertile soils with suitable properties is often one of the main limitations for appropriate recultivation. Whilst less fertile soil or even inert construction or industry residuals may be used to recultivate the lower layers, the top layers require using engineered soils with appropriate physical, biological and chemical properties. These properties depend on the purpose of the final use of sites. Apart from making sure that the engineered soils have appropriate physical, chemical and biological properties, it is also necessary that they do not contain excessive concentrations of potentially hazardous substances when it comes to agricultural use.The primary aim and objective is to develop technologies for producing fertile soils from inorganic and organic waste resulting from construction work or opencast mines and other industrial processes. The main categories of waste where the Slovenian recycling rate is lower than the EU rate are sewage sludge and non-hazardous construction and demolition waste. In this contribution, we are studying how to improve non-fertile soils with various additives of secondary origin to prepare fertile soil mixtures that enable a safe space greening or even food production.Acknowledgements: Project LIFE20 IPE/SI/000021 je co-financed by European Union.Keywords: agricultural landscape, land rehabilitation, recultivation, top soil
Investigating Intermittent Flow Stagnation at Channel Confluence of Braided River
Authors: Handique Anurag , Kalyani Shakti , Sarma Arup Kumar , Bhattacharjya Rajib Kumar
Published: February 2023

Confluences of rivers are classified as one of the most intricate hydrodynamic environments. The convergence of incoming flows at confluences generated by two rivers or subchannels in large braided rivers creates complex fluid motion patterns, including the growth of large-scale turbulence formations. A study on the dynamics of flow mixing and propagation from the adjoining channels could be tricky as the channels consisting of the confluence usually acts as a flow barrier to each other. The flow in the dominant channel would initially act as a virtual barrier to the incoming channel, intercepting its free movement to the main channel. Post this stagnation, the less dominant flow gain energy because of a temporary rise in its level due to flow accumulation and eventually merge into the main stream in due course of time. However, when the confluence involves two channels of relatively similar strengths, primarily observed in large complex braided rivers, the complete or partial flow stagnation is observed in both the sub-channels alternatively in subsequent times. This distinctive flow phenomenon was first observed by our research team during 2004 while doing a hydrographic survey for modelling purpose in the Brahmaputra River of Assam, India, and is popularly called “Hamol” by the riverine community. Owing to this peculiar occurrence, there can be several implications on the river, such as changes in sediment dynamics, influencing the aquatic biota and habitat alterations, etc. For numerical river flow modelling, accurately simulating confluence hydrodynamics is a significant challenge. In this work, this phenomenon is investigated in a confluence composed of two sub-channels with different strengths through a mathematical model study. The model is simulated in the Brahmaputra River near Bahari, Barpeta from the viewpoint of its complex braiding patterns existent in this stretch. A TVD McCormack predictor corrector technique is used in the mathematical model to solve a modified form of boundary fitted shallow water equations in the MATLAB environment. The stability of the model is governed by the Courant criteria, with the Courant number being less than unity. Through the model study, the variations of the depth-averaged streamwise velocities and the simulated flow depths in the grid points prior to the confluence juncture in the less dominant channel are compared in different timesteps. Alongside, the characteristic of such transitions is examined for different discharge ratios of the two adjoining channels. The study indicated the efficacy of the mathematical model in capturing the “Hamol” phenomenon observed practically in the field.
Social safety in the field – preparing the students, our future colleagues
Authors: Peters Kalijn , Verhoeve Steye , Nijland Wiebe
Published: February 2023

Watching the documentary ‘The Leadership’ led to a consentient discussion amongst colleagues. In this documentary a group of female scientists set off on a cruise to learn about and experience leadership. Personal experiences, what happens on board and statistics about social safety, show that feeling socially safe and included is still an issue amongst (female) scientists, especially when working in the field. The significantly high numbers of female field scientists in STEM research having experienced discrimination, gender inequality and (sexual) harassment cannot be ignored, so we decided this subject has to be embedded in our bachelor curriculum.In order to enhance social safety in our earth sciences program, we set up a workshop on this subject for our bachelor students as part of a 15ECTS fieldwork course. In the field, students are physically and mentally challenged, while operating in an often unfamiliar environment, working in bigger and smaller groups, for longer periods of time and integrating all they have learned over the past year(s). With the many challenges this encompasses, they will likely face the boundaries of their comfort zone. This makes them more vulnerable and increases the risk of creating an unsafe working, studying/living environment. However, when treated with care, these experiences can have a significant positive impact on the students personal growth and become beneficial to their professional skills and learning.The workshop we designed starts with discussing daily practicalities and individual responsibilities, including sanitary hygiene and proper field-equipment, and continues with professional attitude, an exercise on group dynamics, how to function in a team that is not your own choice, and getting to know your teammates in a playful manner. We finish with the discussion of (sexual) harassment, providing tools to become an active bystander, and giving the students case studies of socially (un)safe settings in the field. They present these case studies to each other on how they would react, reflecting on their own capabilities and responsibilities.After this first year, student evaluations and discussions with field staff point out that this is a valuable part of the fieldwork. For example the staff could more easily refer to some manners discussed in the workshop, and the students could recognize the case studies and use this to tackle unsafe situations at an earlier stage. We now continue with optimizing the existing workshop, and would like to exchange experiences about this subject with colleagues to enhance improvement of social safety and personal growth in the field for both students and teaching staff.
April 3, 2022 in-situ ESP event as observed by Solar Orbiter, ACE and Stereo
Authors: Ho George , Mason Glenn , Allen Robert , Kouloumvakos Athanasios , Wimmer-Schweingruber Robert , Rodríguez-Pacheco Javier , Gómez-Herrero Raúl
Published: February 2023

The propagation and radial evolution of energetic particle events can only be studied by multiple-point simultaneous in-situ measurement within the heliosphere.  The joint ESA/NASA Solar Orbiter mission that was launched in February 2020, is designed to study the Sun and inner heliosphere in greater detail than ever before.  The Energetic Particle Detector (EPD) investigation on Solar Orbiter is a suite of four different sensors that measure the energetic particles from slightly above solar wind energies to hundreds of MeV/nucleon. Since launched, EPD already observed numerous large solar energetic particle (SEP) and energetic storm particle (ESP) events inside of 1 au in greater temporal and spectral resolutions than ever before.  Many of these events were also measured by spacecraft at 1 au such as ACE and/or STEREO. On April 2, 2022, an active region (AR 12975) on the western limb (W80) of the Sun produced a large SEP event and associated fast moving (>1400 km/s) coronal mass ejection (CME) and a CME-driven interplanetary shock (~1900 km/s).  During that time, the Solar Orbiter spacecraft was cruising near its perihelion distance (~0.35 au) at W109 relative to the Earth-Sun line, and the STEREO Ahead spacecraft was at E35.  Together, the particle instruments on these probes measured the SEP/ESP and the plasma and field instruments detected the associated interplanetary shock/CMEs on April 2-3, 2022.  In this paper, we report the multi-spacecraft observations of this event that were measured by Solar Orbiter, and we discuss the propagation and transport of SEPs from 0.3 to 1 au.
The role of the bole: constraints in the remobilization of stem reserves under experimental carbon limitation
Authors: Landhäusser Simon M. , Fermaniuk Coral , Fleurial Killian G. , Wiley Erin
Published: February 2023

Assimilated non-structural carbohydrates (NSC) can be stored as reserves in plants and remobilized during periods of asynchrony between carbon acquisition and carbon demand to fuel essential metabolic functions and growth. However, the framework of NSC allocation to reserves and their remobilization remains unclear, especially for mature trees which potentially can store large quantities of reserves. Here, we explore the role of stem reserves and potential constraints in their remobilization in large Betula papyrifera trees. To explore reserve remobilizations between organs, we use different patterns of phloem girdling to induce carbon stress and to isolate crown, stem, and root NSC storage pools.  Our results suggest that NSC reserves in the stem tissues may not be easily remobilized to other, more distant, organ sinks. However, we also found that some root reserves may be allocated toward the lowermost stem/root collar position, indicating that under carbon limiting conditions the roots might not be the strongest sink for NSC reserves. We suggest this response represents an adaptive recovery strategy for a collar-sprouting species like B. papyrifera, which occupies areas prone to aboveground disturbance. We also found that storage capacity of tissues (here stem wood and crown) can far exceed the concentrations that are normally stored in these trees.  Additionally, we found stem NSC concentrations positively correlated with disease resistance and branch water content.  These relationships suggest that a maintenance of greater stem reserves may be required to support other important roles directly or indirectly, such as defense or spring leaf flush, respectively.  Overall, it appears that the remobilization of different organ reserve storage pools is regulated somewhat autonomously, which, particularly under carbon limiting conditions, could potentially limit the sharing of reserves within a large tree.
The suddenly occurring Mesoamerican megadrought during the Little Ice Age (1400 to 1600 AD)
Authors: Winter Amos , Zanchettin Davide , Lachniet Matthew , Burnett Allison , Warken Sophie , Cheng Hai , Rubino Angelo , Miller Thomas
Published: February 2023

The Little Ice Age (LIA), a multicentennial period of predominant anomalously cold conditions on Earth, is among the most important periods that characterized climate evolution during the pre-industrial part of the last millennium. However, LIA remains enigmatic in many aspects, including its magnitude, timing, duration, and spatial extent, especially concerning the response of tropical hydroclimates.  Here we focus on Mesoamerica, where many proxy-based reconstructions show one or more Major Drying Events (MDEs) during the LIA.   We present new results from speleothem GU-Xi-1, which was recovered in 2007 from Xibalba cave (approx. 16.5˚N, 89˚W, near the Belize - Guatemala border) and was active and dripping at the time of collection. The most salient feature of GU-Xi-1 is a prolonged period of persistently heavy oxygen isotope values between around 1400 and 1600 CE. This positive isotope incursion was most likely a major drying event based on the well-known amount effect common in the tropics. In this contribution, we will illustrate the extensive drought described by our record during the LIA and propose a mechanism explaining its rapid initiation (within perhaps 20 years), possibly connected with natural forcing.
Large volcanic eruptions elucidate source vs sink limitations to tree growth
Authors: Cabon Antoine , Anderegg William R L
Published: February 2023

Forest productivity projections remain highly uncertain, notably because underpinning physiological controls are delicate to disentangle. Whereas photosynthesis (carbon source) has been commonly assumed to drive tree growth, growing evidence show that direct limitations to cambial activity (sink limitation) represent a substantial control of tree growth. It nevertheless remains unclear to which extent source and sink limitations interact to determine tree growth because these processes mostly respond to the same environmental cues. Radiation is a notable exception, but its annual variations are typically small and covary with multiples cofactors in natural settings. Large volcanic eruptions, which have been suggested to enhance forest photosynthesis globally through diffuse light fertilization, provide a unique opportunity to retrospectively isolate source and sink activities. Here, we use a multi-proxy dataset of tree-ring records distributed over the extra-tropical Northern Hemisphere to investigate the effect of eruptions on tree photosynthesis and growth. Dual tree-ring isotope records (13C and 18O) denoted a widespread 2–4 years increase of photosynthesis following eruptions, likely as a result of diffuse light fertilization. We found evidence that enhanced photosynthesis transiently drove ring width, but the latter further exhibited an independent decadal anomaly. Our results provide empirical evidence of essentially decoupled photosynthesis and tree growth response to large volcanic eruptions, hence suggesting widespread sink limitation to tree growth over the Northern Hemisphere.