bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Atlantic multidecadal variability on North Atlantic tropical cyclones and extratropical transition
Authors: Baker Alexander , Vidale Pier Luigi , Roberts Malcolm , Hodges Kevin , Seddon Jon , Tourigny Etienne , Lohmann Katja , Roberts Christopher , Terray Laurent
Published: March 2022

In the North Atlantic, approximately half of tropical cyclones undergo extratropical transition, and landfalling systems pose risks to populous midlatitude regions. The frequency of tropical-origin storms across the midlatitudes is projected to increase under anthropogenic climate change, but multi-model studies are required to help reduce uncertainties. One key uncertainty is the role of Atlantic multidecadal variability (AMV), a robust understanding of which will help contextualise projections. We assess the impacts AMV+ and AMV– on basin-wide tropical cyclone and extratropical transition activity in an ensemble of coupled sensitivity experiments from CMIP6 HighResMIP. We used objective methods—a Lagrangian feature-tracking algorithm and cyclone phase-space analysis—to identify tropical cyclones undergoing extratropical transition and present analysis of changes in cyclogenesis, tracks, and intensity in response to AMV forcing.
Assessing assemblages from foraminiferal propagule banks: A combined approach of culture experiments and eDNA metabarcoding
Authors: Weinmann Anna E. , Morard Raphaël , Hassenrück Christiane , Goldstein Susan T. , Li Qingxia , Raposo Débora , Triantaphyllou Maria V. , Langer Martin R.
Published: March 2022

Shallow-water banks of foraminiferal propagules (tiny juveniles <63 µm) harbor a hidden assemblage composition that has altered our understanding of traditional distribution patterns. Propagules can be transported well beyond their environmental limits and remain dormant until local conditions become suitable. Therefore, the composition of propagule assemblages is expected to differ from “adult” assemblages. This offers various opportunities for a better understanding of foraminiferal reactions to environmental changes and also of the variability of living foraminiferal populations throughout the year.

To date, propagule assemblages have only been analyzed “passively” through growth experiments with propagule banks under laboratory conditions. Here, we apply for the first time a combination of a multi-week cultivation experiment and eDNA metabarcoding of the different size fractions.

Sediment samples were taken from a shallow lagoon in Corfu (Greece) and sieved over 63 µm to separate the propagule bank from the coarser fraction. The in-situ material of the sampling site was used as a baseline for the subsequent experiment (T0). The finer fraction (<63 µm) was set up in a culture experiment for 15 weeks under stable conditions (22°C, 38 psu, constant aeration). The cultures were repeatedly harvested for grown foraminifera (>63 µm) every 5 weeks (T1–T3). At the same intervals, samples were taken and re-sieved over 63 µm for eDNA metabarcoding of both size fractions.

The morphology-based count data of the foraminiferal specimens revealed significantly different assemblage compositions after each harvest (T0–T3). The differences between the in-situ (T0) and the experimental samples (T1–T3) were most distinct, indicating a specific composition of the propagule bank. The differences between in-situ and experimental assemblages as well as the shifting assemblage compositions over time were mirrored by the metabarcoding data from the respective intervals. Our results highlight the potential for metabarcoding to complement and expand insights gained from morphology-based approaches in foraminiferal studies.
Identifying the drivers of Subantarctic mode water thickness across the south Pacific.
Authors: Pimm Ciara , Meijers Andrew , Jones Dan , Williams Ric
Published: March 2022

Subantarctic mode water (SAMW) is a subsurface water mass which is formed through surface heat loss. This leads to thick winter mixed layers which are then subducted resulting in a low stratification subsurface watermass. SAMW formation regions are important for the storage and transport of heat and carbon. Recently, it was found that SAMW layers are getting thicker each year over much of the Southern Ocean. In the South Pacific mode water formation region, a central and eastern pool of mode water has been found to have winter thicknesses that vary strongly interannually and out of phase across the basin. This is associated with peaks in sea level pressure variability at a quasi-stationary anomaly situated between the two pools.

 

To investigate how this external forcing, as well as the propagation of upstream anomalies, affects these mode water pools, a set of adjoint sensitivity experiments are conducted. The traditional approach to adjoint sensitivity experiments in the ECCOv4 state estimate uses a vertical mask that is fixed at all times. Instead, the adjoint is developed so that a density following mask is employed, which more closely reflects how water masses preferentially spread along density surfaces.   

 

The ECCOv4 state estimate, with this new feature, is used to conduct a set of adjoint sensitivity experiments that directly quantify the role of local versus remote forcing in setting the variability in regional mode water properties raised in recent studies. Two separate adjoint sensitivity experiments are completed with horizontal masks in the two pools of mode water in the south east Pacific mode water formation region. The objective function used here is the yearly averaged heat content over the pool and the density surfaces. The analysis compares the effect of local versus remote forcing, identifying the separate effects of  the wind stress, heat flux, and freshwater flux. The sensitivities of the SAMW are then identified in terms of the different forcing components associated with  the atmospheric modes, ENSO and SAM.
Sea-ice derived meltwater stratification slows thebiological carbon pump: results from continuousobservations
Authors: von Appen Wilken-Jon , Waite Anya , Boetius Antje ,   FRAM team
Published: March 2022

The ocean moderates the world’s climate through absorption of heat and carbon, but how much carbon the ocean will continue to absorb remains unknown. The North Atlantic Ocean west (Baffin Bay/Labrador Sea) and east (Fram Strait/Greenland Sea) of Greenland features the most intense absorption of anthropogenic carbon globally; the biological carbon pump (BCP) contributes substantially. As Arctic sea-ice melts, the BCP changes, impacting global climate and other critical ocean attributes (e.g. biodiversity). Full understanding requires year-round observations across a range of ice conditions. Here we present such observations: autonomously collected Eulerian continuous 24-month time-series in Fram Strait. We show that, compared to ice-unaffected conditions, sea-ice derived meltwater stratification slows the BCP by 4 months, a shift from an export to a retention system, with measurable impacts on benthic communities. This has implications for ecosystem dynamics in the future warmer Arctic where the seasonal ice zone is expected to expand. (Published in Nature Communications, December 2021, https://www.nature.com/articles/s41467-021-26943-z )
Adsorption of Chromium (VI) by soil sediments in heterogeneous porous media: a case study in Rupnagar district of Punjab, India.
Authors: Ganguly Shreya , Ganguly Sayantan
Published: March 2022

Chromium (VI) is a known toxin and carcinogen which is still abundantly used in various industries primarily as an anti-corrosive agent. Thus in case of accidental spillage of it, without proper treatment and disposal, it might leach into the ground and pollute the soil and the groundwater table. The reactivity and solubility of Cr(VI) is extremely high in water making it more dangerous if consumed. The transport and fate of a contaminant in sub-surface porous media is governed by the processes of advection, dispersion and sorption. The transport of Cr (VI) is highly influenced by the processes of adsorption and desorption. The soil sediments have different physical and chemical properties which affect their adsorption efficiencies to a large extent. Hence, the knowledge of adsorptive capacities of the soil sediments is necessary to determine the time of travel of the contaminant plume in the porous media. The present study is conducted to determine the adsorption efficiency of natural soil if Cr(VI) gets accidentally leaked from a stainless steel manufacturing plant located in Rupnagar district of Punjab, India. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were performed to assess the surface morphology and chemical composition of the soil layers located above the local water table. The initial concentration of Cr(VI) was taken to be 2 mg/l to conduct the batch adsorption studies. The optimum values of parameters like: dose of soil, change of pH of the solution, the time of contact between the adsorbate and the adsorbent and concentration of metal ion adsorbed, are determined in the study. Langmuir, Freundlich and BET adsorption isotherms along with kinetic models were also examined to investigate the mechanisms of adsorption.

Keywords: Chromium (VI); Adsorption; Natural attenuation; Batch adsorption studies; Adsorption isotherms; Kinetic models.
Spatiotemporal patterns of crop diversity reveal potential for diversification in Swedish agriculture 
Authors: Sjulgård Hanna , Colombi Tino , Keller Thomas
Published: March 2022

Objective

Diverse cropping systems are associated with multiple ecosystem services and are suggested to alleviate the effects of drought and heat stress. The magnitude and frequency of extreme weather events are projected to increase in the future due to climate change, and diverse cropping systems might therefore become key for food security. However, there is still limited information on the spatiotemporal variation of crop species diversity and how it relates to differences in climate or soil type. We aimed at quantifying how crop diversity developed over time at the national and regional scale in Sweden between 1965 and 2019, and how crop species diversity is related to climatic factors and soil texture.

Methods

Sweden is an interesting case study due to the large range in latitude from north to south. The analyses were conducted using national databases containing historical records of crop production and climate data, as well information on soil texture. To quantify crop species diversity, species richness and a crop diversity index that reflects the area-weighted equivalent number of crops were used.

Results

Crop species richness and crop diversity index increased from north to south in Sweden, and our results showed a positive relationship between mean annual temperature and latitude to crop diversity at national level. The positive relationship shows how mean annual temperature and length of the vegetation period control crop diversity across the country. There were no significant relationships between crop diversity and mean annual precipitation and soil texture, respectively. Crop species richness did not change over time at national level while crop diversity index experienced a temporal decrease. At the county level, different temporal trends were observed among counties: in some counties an increase in crop diversity and species richness occurred, while other counties had no change or a temporal decrease.

Conclusions

The differences in the results between national and county level show the importance to include different scales in the examination of temporal developments of crop diversity. Although crop diversity index decreased over time at national level, the temporal increase observed in almost half of the counties suggest that it is possible to increase crop diversity in Sweden. The different temporal changes between counties imply that crop diversity is affected by an interplay between natural and socioeconomic factors. Natural factors constrain which crops can be grown, but to promote diversification of agricultural crops in the future, socioeconomic factors need to be considered.
Grain boundaries as reactive fluid pathways in rocks
Authors: Hernández-Filiberto Lorena , Putnis Christine V. , Putnis Andrew , Austrheim Håkon
Published: March 2022

The presence of aqueous fluids is ubiquitous in the Earth’s crust. Grain boundaries play an important role in enabling fluids to penetrate through the rock system. Their influence in fluid-rock reactions that might lead to relevant processes such as mineral replacements, the formation of new minerals and dissolution of others, element mobilization, variations in rock density, changes in stress distribution, mass transfer, etc., are commonly observed in many rock samples as well as generated and observed in laboratory experiments. As a product of these reactions, porosity and fractures might also be generated and potentially allow the fluid to penetrate even further.

Here we present our first analyses on different rock samples where the fluid-rock interaction has been induced through hydrothermal laboratory experiments using either Carrara Marble or plagioclase samples. The evidence for such interactions having previously occurred in natural rocks has been investigated in a sequence of a granulite rock samples from the Bergen Arcs in Norway. Using light microscopy as well as SEM, EDX and Electron Microprobe analysis we have investigated possible fluid pathways and evidence of fluid-mineral reactions as well as the mechanisms that could explain such processes.
What can we learn from eddy-induced signatures on sea surface temperature ?
Authors: Barboni Alexandre , Stegner Alexandre , Moschos Evangelos
Published: March 2022

Anticyclonic (cyclonic) eddies are commonly considered to have a warm (cold) signature on the sea surface temperature (SST). However several recent studies revealed the existence of a non-negligible fraction of "inverse" eddy-induced SST anomalies : cold-core anticyclones and warm-core cyclones. Using remote sensing and in situ observations in the Mediterranean sea over 3 years (2016-2018), we built an eddy core surface temperature index and showed that these inverse SST signatures have a seasonal distribution, scarce in winter but very common and even predominant in early summer. Warm-core cyclones and cold-core anticyclones proportion gets a maximum of 70% of the signatures in May and June, with a quick rise in coincidence with spring restratification and mixed layer depth (MLD) shallowing.

To understand further the physical processes we used a simple 1D vertical model of a water column forced by a seasonal surface temperature flux. It is a known observation that MLD is deeper (shallower) inside anticyclones (cyclones), and we tested if this difference of vertical structure alone was sufficient to reproduce eddy-induced SST signature inversion during spring restratification. This proved not to be enough, and it is only by taking into account a differential diapycnal eddy mixing - increased in anticyclones and reduced in cyclones - that we reproduce correctly, in agreement with the observations, the eddy surface temperature inversion. Furthermore, idealized 3D numerical simulations (so far for an anticyclone) at sufficiently high resolution were able to reproduce the shift from a winter warm-core eddy to a summer cold-core eddy, and they revealed a dependence on the wind forcing strength and frequency in the magnitude of the eddy-induced SST signature.

This simple 1D model tends to show that vertical mixing modulation by mesoscale eddies might be a key mechanism explaining inverse eddy SST signatures. It also suggests beyond that these signatures could represent an integrated signal of both temperature and momentum flux forcings at the scale of the eddy. 
How physical properties can unveil the biological processes in the water column: a multi-platform study of the extreme bloom of Rhizostoma pulmo jellyfish in the Gulf of Trieste,  April 2021 case study.
Authors: Reyes Suarez Nydia Catalina , Ursella Laura , Tirelli Valentina , Ličer Matjaz , Querin Stefano , Cardin Vanessa
Published: March 2022

On 7 April 2021, an exceptional bloom of the scyphomedusa Rhizostoma pulmo was observed in the Gulf of Trieste (Italy). Blooms of these species in the northern Adriatic Sea have been reported since the late 1800s, however, the density of jellyfish observed in 2021 reached dozens of specimens per cubic meter. In this work, we analyze the bloom from a multi-platform approach using observation and model data at different time scales. This study aims to contextualize the oceanographic/environmental conditions that may have contributed to the exceptional aggregation of the scyphomedusa Rhizostoma pulmo along the northernmost coast of the Adriatic Sea. Our study shows that 1) the bloom was probably enabled by anomalous warm sea conditions during winter 2020, allowing specimens that reproduced in 2020 to survive and reach considerable abundance and sizes by early 2021; 2) strong wind events, such as the Bora wind for the Gulf of Trieste, enhanced upwelling and mixing processes in the gulf thus bringing the jellyfish present in deeper waters to the surface and clustering them along the coast.
Drivers of multi-decadal in-stream nitrate regime shifts in a large European catchment
Authors: Wachholz Alexander , Jawitz James W , Büttner Olaf , Jomaa Seifeddine , Merz Ralf , Yang Soohyun , Borchardt Dietrich
Published: March 2022

Long-term monitoring shows evidence of persistent changes in the magnitude and timing of the seasonal pattern and C-Q relations of nitrate concentrations in rivers, with possibly grave effects on aquatic ecosystems. Seasonal patterns of riverine nutrient concentrations are driven by a complex interplay of inputs, transport, and in-stream processing. Over multi-decadal periods, each of these factors may change due to socio-economic factors such as consumption patterns, governance regimes, or technological control measures. Here we test the hypothesis that observed multi-decadal changes in stream nitrate seasonality could be explained by changes in the relative importance of catchment nutrient sources over time. We analyze 66 years of shifting nitrate seasonality in a large, central-European river (Elbe) during a period of significant socio-political changes (1954 to 2019), with correspondingly significant changes in the sources of anthropogenic nitrate emissions. We show that the in-stream nitrate seasonality of the River Elbe changed significantly from a weak seasonal pattern (chemostatic) with peak concentrations during summer in the 1950s to a strong seasonal pattern (chemodynamic) with peak concentrations during winter in the 1990s. We link these shifts to a succession of technical/ political developments which influence the contribution of point and diffuse sources over time. Such shifts in seasonal concentration patterns can significantly impact the macronutrient (carbon, nitrogen, phosphorus) ratios in rivers, which in turn highly affect the health of aquatic ecosystems.
Biogeophysical effects of land use and land cover change not detectable in CMIP6 warmest month.
Authors: Grant Luke
Published: March 2022

In addition to their changes to carbon pools, land use and land cover changes (LULCC) alter climates biogeophysically through their effects on surface fluxes for energy and water. These resulting climatic changes in temperature manifest differently across study type (observational or model-based) and spatial-temporal scales depending on the predominance of albedo, evaporative fraction and surface roughness as causal factors. With growing future demand for land-exhaustive activities to address societal needs and interest in mitigation strategies involving reforestation/afforestation, it is important to understand how past LULCC contributed to climate change. Here we assess the prevalence of the historical LULCC signal in the warmest average month of daily maximum temperatures using regularized optimal fingerprinting for detection and attribution. We use the simulations of four global climate models from CMIP6 historical and hist-noLu experiments and separate observations from the Climatic Research Unit and Berkley Earth. Aggregating data according to the new IPCC AR6 reference regions and regressing observations onto hist-noLu and lu (historical - hist-noLu) in a 2-way regression, we find that LULCC is not sufficiently detectable at continental and global scales for four GCMs and their multi-model mean. This is confirmed by the nearly unchanging detectability of historical climate change in separate 1-way regressions for historical and hist-noLu. To further explore lu, we confirm the predominance of noise and the non-local effects of LULCC over its local effects by finding insignificant signal-to-noise ratios for the fingerprint of forest cover on lu using a principal component analysis.
Parameter estimation using Cluster array magnetic field data: perfomance and limits of Capon's method
Authors: Narita Yasuhito , Toepfer Simon , Glassmeier Karl-Heinz , Motschmann Uwe
Published: March 2022

Finding a set of model parameters using the in-situ spacecraft data (such as in the Earth or planetary magnetospheres and in the solar wind) is one of the common exercises in the field of space physics. Above all, parameter estimation using Capon's minimum variance projection, originally developed in the field of array seismology, has successfully been applied to recognizing various structures or spatial patterns in space. Examples of the Capon method can be found in the analysis of the wave structures (plane waves, spherical waves, and phase-shifted waves) and the static, large scale structures (planetary dipolar field and higher-order fields). In order to extend the scientific potential of array magnetic field data such as the Cluster, THEMIS, and MMS missions, the performance and the limits of Capon's method are studied in detail using both analytical and numerical approaches. Our findings are: 1) Capon's method is a simple yet robust implementation of the maximum likelihood method, and 2) its accuracy or error can be evaluated analytically. It is suggested that other inversion techniques such as the least square fitting, the singular value decomposition, the Tikhonov regularization, and the eigenvector-based method may be as competitive as Capon's method when the statistical method is limited in the data analysis. Data analysts have thus a wider range of choices for the structure recognition using array data. 
Modelling the impact of land use change on floods and drought in a groundwater-dominated catchment
Authors: Collins Sarah , Verhoef Anne , Mansour Majdi , Macdonald David
Published: March 2022

In the UK, land use and land management change are being considered as part of a strategy to tackle flooding; the term natural flood management (NFM) is used in the UK to refer to this approach. Although evidence is limited, it is thought that practices considered as NFM, such as woodland planting or cover cropping, increase soil water storage and infiltration through improved soil structure, potentially reducing flooding within catchments where applied. Moreover, we know that trees and woodland have higher interception than shorter vegetation, increasing soil moisture deficit. We simulate what effect these land use and management changes have in the River Coln catchment (Upper Thames, UK), which is characterised by permeable geology and arable farming. The catchment has experienced both surface water and groundwater-driven flooding in recent history and is also important in maintaining summer low flows in the River Thames.  

The land surface water balance was modelled with the detailed, field-scale hydrological model SWAP. Recharge from the SWAP model was passed to a semi-distributed groundwater model, which produces groundwater baseflow, and direct runoff from SWAP was passed to a linear reservoir model to produce surface runoff. Soil information (such as soil hydraulic parameters) was based on the NATMAP database; vegetation parameters (e.g. typical crop rotations or forest types) were derived from stakeholder workshops, surveys and interviews, and expert elicitation. Soil and farm management decisions were implemented by perturbing the SWAP soil and vegetation parameters. The parameters of the surface water routing and groundwater components were calibrated within a Monte Carlo framework.

Overall, we found that land use and land management measures have very limited potential for reducing flooding in permeable catchments, where the primary driver of high flows is high winter groundwater levels. We found that only large-scale coniferous planting had the potential to reduce winter peak flows and flooding in the Coln (e.g. reduction of 21−27% with two-thirds of catchment as coniferous woodland), but that this would decrease summer mean flows (12% reduction in July mean flow, 8% in August). The levels of coniferous woodland required to achieve these reductions in winter high flows are unrealistic, given the large area of productive arable land that would need to be converted to woodland and the limited ecological benefits of coniferous woodland.
Overshooting the tipping point threshold for the Greenland ice-sheet using a complex ice-sheet model
Authors: Bochow Nils
Published: March 2022

The rise of the global sea-level due to the melting of the Greenland ice-sheet poses one of the biggest threats to human society in the 21st century (IPCC, 2021). The Greenland ice sheet has been hypothesized to exhibit multiple stable states with tipping point behavior when crossing specific thresholds of the global mean temperature (Robinson et al., 2012). In regards to the desultory efforts to reduce the global emissions it becomes more and more unlikely to reach the 1.5°C goal by the end of the century and a crossing of the tipping threshold for the Greenland ice sheet becomes inevitable. First early-warning signals of a possible transition have already been found (Boers&Rypdal, 2021). However, it is known that a short-term overshooting of a critical threshold is possible without prompting a change of the system state (Ritchie et al., 2021). Using a complex ice sheet model, we investigate the effects of different carbon-capture scenarios after crossing the tipping threshold for the Greenland ice sheet. We are able to sketch a stability diagram for a number of emission scenarios and show that temporarily overshooting the temperature threshold for Greenland might be quasi-irreversible for some of the emission scenarios.

IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of
Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-
Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M.
Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)].
Cambridge University Press. In Press.

Robinson, A., Calov, R. & Ganopolski, A. Multistability and critical thresholds of the Greenland ice sheet. Nature Clim Change 2, 429–432 (2012).

Boers, N. & Rypdal, M. Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point. PNAS 118, (2021).

Ritchie, P. D. L., Clarke, J. J., Cox, P. M. & Huntingford, C. Overshooting tipping point thresholds in a changing climate. Nature 592, 517–523 (2021).
Seasonal variations of morphological and sedimentological characteristics of some beaches in the northern Latium coastal area (Italy).
Authors: Piazzolla Daniele , Iacobelli Ginevra , Manfredi Frattarelli Francesco , Scanu Sergio , Marcelli Marco
Published: March 2022

The coast is the “hinge” between two environments: the continental shelf and the emerged lands. The coastal environment is strongly dynamic, as a result of the differential action of the marine weather forcings on the geomorphological structures. It has a fundamental ecological and biological role but at the same time, it is home to many industrial activities. The spatial overlap of very different and sometimes incompatible coastal uses often causes damage to habitats and ecological communities.

In this work, the morphological and sedimentological characteristics of some beaches included in the Physiographic Unit Capo Linaro - Capo Anzio (Latium, Italy) were investigated. The physical characteristics of the beaches and the changes in the morphological structure, from the dune to the shoreline, between winter and summer were examined, to acquire useful data for the analysis of the sedimentary balance and the seasonal evolution of the shoreline. Four beach areas, between Marina di Cerveteri in the north and Castel Porziano in the south, which present a morphology relatively undisturbed by human action, were investigated.

The sedimentological characteristics were examined by analyzing sediment samples, while volumetric variation between the winter and summer seasons were obtained using two distinct methods: a graphical reconstruction of the trend of the beach profile and a mathematical-analytical methodology. During summer, the morphological profiles showed a less articulated structure than in the winter, with an elongation of the beach profile. Textural variations were observed between the summer and winter periods, but these variations are not isolated in single slope breaks and occur along with the entire morphological profile. Finally, the analytical method for the volumetric calculation is reliable especially in poorly articulated topographical situations (discrepancies with the graphical method of less than 2%).

This work was carried out as part of the "FIUMICINO-1" research program, funded by the Port System Authority of the Central Northern Tyrrhenian Sea.
Orbital-scale deoxygenation trends driven by ventilation in Cretaceous ocean
Authors: Sarr Anta-Clarisse , Laugié Marie , Donnadieu Yannick , Ladant Jean-Baptiste , Raisson François
Published: March 2022

Mechanisms driving cyclicity in the marine realm during hothouse climate periods in response to Earth’s orbit variations remains debated. Orbital cycles fingerprint in the oceanographic records results from the effect of terrestrial (eg. weathering-derived nutrient supply, freshwater discharge) and oceanic (eg. productivity, oxygenation) processes, whose respective contribution remains to be defined. Here we investigate the effect of extreme orbital configurations on oxygenation state of the ocean using ocean biogeochemistry simulations with the IPSL-CM5A2 Earth System Model under (CT) Cenomanian-Turonian boundary conditions. We also use an additional inert artificial tracer allowing to compute the age of water masses, corresponding to the time spent since the last contact with the surface. Our simulations show that small ocean ventilation changes triggered by orbitally-induced variations in high latitude deep water formation have strong impact on the oceanic oxygen spatial distribution. It is particularly true for the proto-Atlantic basin which is the less oxygenated basin during the CT (Laugie et al., 2021). The eight sets of orbital parameters tested here imply changes in the Atlantic anoxic seafloor area going from 20 to 80%. All three parameters describing the Earth’s orbit (eccentricity, precession and obliquity) show a substantial control on these fluctuations. We also note that orbital fluctuations result in important changes in continental runoff but the impact remains highly localized to coastal environments – the open ocean mainly responding to the ocean ventilation. Last but not least, changes in productivity induced by the orbital parameters remain spatially heterogeneous and could be responsible for more local signal within a single basin.

 

Laugié, M., Donnadieu, Y., Ladant, J. B., Bopp, L., Ethé, C., & Raisson, F. (2021). Exploring the impact of Cenomanian paleogeography and marine gateways on oceanic oxygen. Paleoceanography and Paleoclimatology, 36(7):e2020PA004202.
Water dynamics in karst soil: Modelling matrix and preferential flow using reservoir cascade scheme approach
Authors: Švob Mirna , Domínguez-Villar David , Krklec Kristina
Published: March 2022

When simulating soil water content (SWC) and dynamics, the reservoir cascade scheme (RCS) approach is considered appropriate in cases when number of parameters for model calibration and validation is limited. This is often the case in Mediterranean karst soils, where due to high rockiness and shallow soil depths it is often difficult to set dense measurement network. In this study, a 1-D model which simulates SWC using RCS approach was developed for a location in central Spain. The soil on the studied site has silt loam texture and is developed on dolomite marbles. The model simulates SWC at daily resolution for six layers in soil that range from 0-50 cm depth, and has three different configurations. Configuration 1 considers only basic RCS module, while configurations 2 and 3 simulate preferential flows in soil as well. Therefore Configuration 2 considers RCS module together with continuous preferential flow module, where between 1 and 5% of available SWC is drained from each soil layer every day. Configuration 3 considers discontinuous preferential flows in addition to two previous modules. Discontinuous preferential flows are active in cases of rainfall events that occur during prolonged dry periods. Simulated SWC values are compared with SWC values measured at five depths in soil, so model parameters are iteratively adjusted to optimize the model results. The simulation produced the best results when implementing Configuration 3: when matrix flow and two kinds of preferential flow are assumed. The model shows that preferential flows could significantly contribute to recharge and should be given more attention in soil hydrological models, especially in karst terrains. It is expected that the model can be implemented in a wide range of locations with karst soils, since it requires limited number of input parameters, but in the same time provides a detailed simulation of soil drainage processes and recharge.
“Carto PMAi” – A measurement campaign to assess exposure risk of workers and public population to the Elongate Mineral Particle of Interest
Authors: Leocat Erell , Deneuvillers Christine
Published: March 2022

The measurement campaign entitled Carto PMAi (EMPi Map) deals with the potential exposure of worker and public populations to Elongate Mineral Particles of interest (EMPi). These particles are the asbestiform and non-asbestiform varieties of the six regulated asbestos minerals and of four other mineral fibers known as carcinogen for human. The aim of this French national project is to give relevant data and recommendations to the Ministries of Health, of Labor and of Environment allowing them to set up legal provisions proportionally to the risk, in case of population exposure to EMPi. The French government mandated the OPPBTP (Professional Body of Prevention in Construction Domain) to lead the project. The “Carto” process that is also used for other campaigns, as for example for crystalline silica measurements, has been developed by the OPPBTP. It implies single operating procedures, measurement monitoring and scientific validation. Several national scientific organizations and asbestos testing laboratories take part to this project. Its first step was to test in field the two measurement protocols with interlaboratory comparison to ensure single practices. The second step is the exploratory campaign to assess the potential exposure of workers and public population to EMPi during the most emissive and the most frequent situations of the construction sector activities.
Qualitative evaluation of flood induced impacts for roads and railways infrastructures: an operative solution within the MOVIDA project
Authors: Petruccelli Natasha , Gallazzi Alice , Molinari Daniela , Hammouti Mohammed , Zazzeri Marco , Ballio Francesco , Sterlacchini Simone , Brath Armando , Domeneghetti Alessio
Published: March 2022

The Po River District Authority has recently signed a research agreement with 20 Italian Universities and the Italian National Research Council (CNR) for updating the Flood Risk Management Plan, in compliance with the European Floods Directive (2007/60/EC). Specifically, the MOVIDA project envisages the efforts of a research consortium dedicated to flood damage modelling (8 Universities and CNR) to provide an Information System capable to perform an analytical evaluation and mapping of expected damage, overcoming the limitations of present maps where the evaluation of risk remains highly qualitative and subjective.      
Proper damage assessment tools were identified for all the five categories of exposed elements foreseen by the EU Directive: population, infrastructures, economic activities, environmental and cultural heritage, and na-tech sites. A dedicated Open Source Geographic Information System (i.e. QGIS plugin) was developed and transferred to Regional Authorities for flood damage evaluation and mapping to all areas at significant risk in the Po District.    
Focusing on road and railway infrastructures, the methodology proposed adopts information coming from different data sources (Regional Geoportals, Open Street Map, etc.) and allows to qualitatively estimate the potential damage impacts of a flood event. Different impact classes (High, Medium, Low and Null) are assigned in relation to the roads category (i.e., Highways, Main, Secondary, Service, Other) or railways type (high-speed train or not), taking into account both the importance of the infrastructure itself (as well as its topographical characteristics: e.g. tunnel, bridge, etc.) and the magnitude of the expected event (i.e., hazard).
The results enable to spatially identify the extent of the impacted infrastructures and the locations of the flooded railway stations, information necessary to identify potential mitigation and support measures to the competent bodies in the organization of the rescue.
Bubble-mediated transport of benthic microorganisms into the water column and its implication on pelagic biogeochemical cycles.
Authors: Schmale Oliver , Jordan Sebastian , Treude Tina
Published: March 2022

Benthic microorganisms transported into the water column potentially influence biogeochemical cycles and the pelagic food web structure. In our present study in the coastal waters of the Coal Oil Point seep field (California) and the Blowout site in the North Sea (abandoned well site 22/4b), we proved the dislocation of microorganisms from the sediment into the water column via gas bubbles released from the seabed. These studies showed that the transport efficiency of benthic methanotrophic bacteria into the water column was dependent on the gas flux intensity from the gas-releasing vent site. Cold seeps represent hot spots of seabed-derived methane emissions to the water column, where physical and biological barriers regulate transport of methane to the atmosphere. In our study, we combined field measurements with a particle-tracking model and demonstrated that sediment resuspension and gas-bubble-mediated inoculation of the water column with methane oxidizing bacteria decreased the methane turnover time by a factor of five. Our findings impressively demonstrate that the bubble-mediated transport of microorganisms influences the pelagic microbial abundance and community composition at gas-releasing seep sites. For cold seeps sites this newly discovered bentho-pelagic transport mechanisms creates a positive feedback on the pelagic methane sink and it seems obvious that this mechanism influences other biogeochemical processes in the vicinity of gas seeps, too.
Does ENSO Affect Global Clear-Air Turbulence?
Authors: Williams Paul , Cheyne Rachel
Published: March 2022

Clear-air turbulence (CAT) is a major hazard to flying aircraft. It is generated by vertical wind shear instabilities in the upper troposphere and lower stratosphere. The El Niño–Southern Oscillation (ENSO) is known to affect the global atmospheric circulation, including the Walker and Hadley cells and the mid-latitude jet streams. Therefore, ENSO has the potential to influence global CAT, both locally in the tropics and remotely in the extra-tropics via teleconnections. Anecdotal evidence supports such an association: there was a large increase in pilots reporting turbulence when flying over the USA during the winter of 1997–98, coinciding with one of the strongest El Niño events on record. However, the influence of ENSO on CAT has not previously been studied.

Here we use reanalysis data to investigate linkages between ENSO and vertical wind shear (and hence CAT) in northern hemisphere winter. Global maps of the anomalous vertical wind shear at 250 hPa are produced from composites of the five strongest El Niño and La Niña events since 1979. These maps indicate that the shear is significantly modified throughout the ENSO cycle across large parts of the globe, including the mid-latitudes and polar regions. The changes are quantified by regressing wind shear in selected high flight-density areas from each winter since 1979 against sea-surface temperature anomalies in the Niño 3.4 region. In the USA and Mexico, for example, we find a sensitivity of around 0.5 m s−1 (100 hPa)−1 °C−1, such that the shear increases by around 50% from 4 m s−1 (100 hPa)−1 during a strong La Niña event to 6 m s−1 (100 hPa)−1 during a strong El Niño event. Significant ENSO–shear relationships are also found in South America, the North Atlantic Ocean, East Asia, South-East Asia, Australia, and Africa.

This study provides the first evidence that ENSO has the potential to influence CAT globally. ENSO’s predictability could be exploited to produce seasonal CAT forecasts globally up to 12 months ahead, which may have practical benefits for the aviation sector, not least because turbulence increases aircraft fuel consumption.
A first version of a comprehensive upper air network service back to 1905 on the Copernicus platform
Authors: Haimberger Leopold , Voggenberger Ulrich , Ambrogi Federico
Published: March 2022

Within the Copernicus Climate Change Service (C3S), several efforts have been initated for providing observation data via the Climate Data Store (CDS). We report on the InSitu Comprehensive Upper Air Network service which is under review for publication via the CDS.
Compared to existing repositories of historical radiosonde and PILOT balloon data, it introduces important novelties:
1) besides long-period records, it contains also short-period records, which are valuable for climate data assimilation efforts such as ERA5
2) homogeneity adjustments for temperature, humidity and wind for all records longer than a year.
3) observation+representativity error estimates derived from ERA5 reanalysis departure statistics
4) additional data and metadata that accompany observation data, such as departure statistics and instrumentation information that can be downloaded in structured form
5) a flexible and user friendly interface, based on that of gridded data from the CDS, that allows to download data in CSV or netCDF formats, suitable for both time series analysis (long single station records) but also reanalysis purposes (all observation records for a point in time). 

Existing challenges regarding the formats to be used and regarding a sensible structuring of the metadata will be discussed. We will also outline the future extension of the service to offer gridded products out of the station records. 
Seismic data as an additional layer of information for large rockslide modelling through back analysis
Authors: Bossi Giulia , Gatter Ricarda , Crema Stefano , Cavalli Marco
Published: March 2022

When studying large landslides any data matters. In fact, in contrast to other scientific branches, data scarcity is a pressing issue especially for high altitude landslides. When large rockslides occur in steep valleys, long runouts can threaten buildings and infrastructures, even though the source area is well above the exposed elements. In such cases, usually no ground-truth monitoring data is available on site, which is needed to understand the causes and processes of the collapse.

Seismic data from a widespread network of seismographs can help to partially fill gaps in the characterization of the above mentioned processes. The most straightforward information that can be inferred from ground motion recordings is the duration of the event – or at least the duration of the most intense and violent phase of the runout. By coupling the velocity of the event with some topographic data leading to the estimation of the detached volume and the deposit distribution, the user may gather sufficient information to produce a satisfactory numerical model through back analysis. In case the topographic data are characterized by high uncertainty and/or poor resolution, seismic records are particularly useful for ground-truthing because they represent an independent source of data.

This study describes the modelling approach used to understand the dynamic of a 365,000 m3 rockslide in the Dolomites (UNESCO World Heritage, North-East Italy). The landslide detached from a steep slope located between 3100 and 2800 m a.s.l. and almost free fell for 600 m. Then it crashed and fragmented in a small rocky hanging valley of glacial origin, subsequently reaching 1400 m a.s.l. with a runout of approximately 2 km. For this area, pre-event and post-event DEMs were available but with different resolution, alignment and coverage. The comparison of pre- and post-event topography allowed the identification and quantification of erosional and depositional areas, the estimation of landslide volume and of the potential errors associated with this type of analysis.

A DAN3D numerical model of the landslide was calibrated using both DEM of Difference (DoD) maps and seismic data. The ground motion records proved to be remarkably useful, as they ensured the reliability of the model notwithstanding the DoD maps intrinsic uncertainties. The seismic data provide a new layer of information in a swiss cheese model of reliability focused on reducing model equifinality and on increasing the overall robustness of the analysis. This finding is fundamental as the results of the back analysis may be used to model and test future scenarios, which can be used to support risk assessment and mitigation.