bluuebunny/crossref_metadata_2025 huggingface dataset:
Convection in future winter storms over northern Europe.
Authors: Berthou Ségolène , Kendon Elizabeth , Roberts Malcolm , Vannière Benoît , Belušic Danijel , Caillaud Cécile , Dobler Andreas , Landgren Oskar , Manning Colin , Vergara-Temprado Jesus
Published: March 2021

Met Office convection-permitting 2.2km simulations over a European domain show 10-20% larger increases in winter mean precipitation at the end of the century compared to their 25km convection-parameterised driving model. We identify individual storms with a maximum vorticity tracking algorithm and look at storm characteristics at their time of deepest minimum sea level pressure. We show that the thermodynamical characteristics of future winter storms are getting closer to present-day autumn storms, with future winter storms showing larger values of convective available potential energy and convective inhibition and more intense rainfall in their warm sector. This suggests that embedded convection in the warm conveyor belt is a good candidate to explain the larger future intensification of rainfall per storm in the 2.2km model compared to the convection-parameterised model. Multi-model analysis is underway to identify whether these conclusions hold in other convection-permitting models.
Experimental study of cemented interfaces for applications in CO2 storage re-using depleted oil and gas reservoirs
Authors: Rossillon Frédérique , Esnault Vivien , Roguet Eléonore
Published: March 2021

The European ERA-ACT REX-CO2 project aims to develop a tool to assess the compatibility of existing wells for CO2 sequestration. Indeed, the reuse of existing wells for storage in depleted reservoirs is an attractive medium-term solution for geological sequestration of CO2.

The mechanical integrity of the wells is a critical point in term of storage durability. A variety of flow paths that could lead to a migration of the stored CO2 to surrounding geological layers or the surface have been identified. Among those, operational feedback shows that a likely leakage route are along the interfaces of the well structure. These potential flow path can be generated by the debonding of the cement sheath from the steel casing or surrounding rocks. One ambition of REX-CO2 project is to ultimately predict the wells integrity as a function of the variations in undergone mechanical loadings. In order to reach this objective, it appears relevant to characterize the mechanical strength of these interfaces.

IFPEN work consists in carrying out mechanical tests on bimaterial specimens to study cement/steel or cement/rock interfaces in different configurations representative of downhole conditions. Two types of tests are performed allowing the characterization of the bonding in two different stress states: the pull-out test and the push-out test. Combined with simulations, these results can either be used directly or feed a damage interface models. The authors are currently running an extensive parametric study, to explore the impact of various downhole conditions, such as pressure or environment, and to CO2 exposure.

The presentation focuses on the mechanical testing methodology. The pull-out test is a tension test performed on a cylinder made of two materials. In this case, the stress pattern is obvious, the interface is loaded in tension. This test is difficult to carry out perfectly due to the weak and scattered behaviour in tension, and finding proper gluing solutions. The push-out test, commonly used in the literature, consists in pushing a plug (steel or rock) into a cement ring to measure the bonding resistance. Despite other push-out tests, a surrounding steel ring ensures the cement confinement and avoid radial cracks. FEM analysis shows stress pattern is more complex than a pure shear at the interface, as often assumed in the literature. An analysis of loading curves enables to understand the different damage stages of the interfaces.
A low-cost wireless sensor network for citizen science water quality monitoring
Authors: von Benzon Elena , Bagshaw Elizabeth , Prior-Jones Michael , Sobey Isaac , Perkins Rupert , Browning Simon
Published: March 2021

We present the first trial of an accurate, low-cost wireless sensor, the ‘Hydrobean’, and base station designed for use by citizen scientists in catchment water quality monitoring. This novel wireless sensor network addresses key concerns identified with current volunteer monitoring programmes, including temporal discontinuity and insufficient data quality. Hydrobean continuously measures electrical conductivity, temperature and pressure and wirelessly transmits these data to an online portal for observation and download by users. These parameters can be used to assess catchment water quality status, with excursions from baseline conditions detected in real time at high temporal resolution. Citizen scientists have an increasingly important role to play in enhancing our scientific understanding of catchment water quality, but their contribution has so far been limited by barriers to access suitable monitoring equipment. Traditional grab sampling techniques result in key contamination incidents being missed and trend analysis limited as samples are analysed discretely, typically on a weekly or monthly basis. Additionally, the quality of data obtained from basic chemical test kits commonly used by citizen scientists does not meet the requirements of many data users. This research explores the role of low-cost wireless sensor networks in advancing the potential of citizen scientists in monitoring catchment water quality. Monitoring equipment available to citizen scientists generally needs to be low cost, so is unlikely to rival professional standard monitoring techniques in the foreseeable future. However, reliable, low-cost sensors which enable continuous, real-time monitoring do now exist for a limited range of water quality parameters and have been used in the development of the wireless sensor network presented here. Critically, Hydrobean and its base station are low cost, low maintenance, portable and robust in order to meet the requirements of community monitoring programmes. Ultimately, a model will be integrated into the real-time analysis of data collected by the wireless sensor network to predict when and where contamination incidents are expected to be affecting catchment water quality. We report initial field results of the Hydrobean wireless sensor network and will discuss ways in which the basic design can be improved in future versions. 
The Dynamic Time Warping as a means to assess modeled solar wind time series
Authors: Samara Evangelia , Chane Emmanuel , Laperre Brecht , Verbeke Christine , Temmer Manuela , Rodriguez Luciano , Magdalenic Jasmina , Poedts Stefaan
Published: March 2021

In this work, the Dynamic Time Warping (DTW) technique is presented as an alternative method to assess the performance of modeled solar wind time series at Earth (or at any other point in the heliosphere). This method can quantify how similar two time series are by providing a temporal alignment between them, in an optimal way and under certain restrictions. It eventually estimates the optimal alignment between an observed and a modeled series, which we call the warping path, by providing a single number, the so-called DTW cost. A description on the reasons why DTW should be applied as a metric for the assessment of solar wind time series, is presented. Furthermore, examples on how exactly the technique is applied to our modeled solar wind datasets with EUHFORIA, are shown and discussed.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870437 (SafeSpace).
Equatorial Pacific bulk 𝛿15N supports a secular increase in subantarctic zone nitrate utilization after the mid-Pleistocene Transition
Authors: Lambert Jonathan , Gibson Kelly , Linsley Braddock , Bova Samantha , Rosenthal Yair , Suprenant Mina
Published: March 2021

Pacific-wide measurements of nitrate and its isotopic composition have furthered our understanding of modern subsurface circulation and have revealed basin-scale connections between oceanographic and nitrogen cycle processes. From the Eastern Tropical Pacific (ETP), the isotopic signature of denitrification is spread zonally and meridionally via subsurface currents. From the Pacific sector of the Southern Ocean, Subantarctic Mode Water (SAMW) penetrates to the low latitudes, delivering nitrate (and likely its isotopic signature) to equatorial surface waters via upwelling. These two regional processes combine to inform much of the thermocline nitrogen dynamics of the Pacific. Here, we compare a new 1.4-Myr bulk sediment 𝛿15N record from the New Guinea margin (IODP Site U1486) to other Pacific 𝛿15N records to track Pleistocene changes in denitrification and SAMW properties. Our results highlight a dramatic increasing 𝛿15N trend after the mid-Pleistocene Transition (MPT) at equatorial sites that is not observed at the New Guinea and California margin sites. Strong 41-ky forcing at equatorial sites and little detectable influence from denitrification (counter to larger denitrification signals at margin sites) suggests increasing 𝛿15N within upwelled SAMW. Because the New Guinea and California margin sites are not below equatorial upwelling, thermocline nitrate is less influenced by SAMW, but rather tracks denitrification in the ETP.

As equatorial Pacific nitrate utilization has not dramatically increased in the late Pleistocene, an increase in subantarctic zone nitrate utilization is proposed. Initiation of increased nitrate utilization appears to commence near the end of the MPT and accelerate near the Mid-Brunhes Event (~430 ka). The observed southward shift of the polar front at this time (associated with increased sea surface temperature), combined with elevated dust/iron flux, may have contributed to greater nitrate utilization and a more efficient biological pump in the subantarctic zone. Through the production (via denitrification) and sequestration (via nitrate utilization) of greenhouse gases, these biogeochemical processes potentially participated in feedbacks associated with both the MPT and the Mid-Brunhes Event. Until reconstructions of subantarctic zone nitrate are extended beyond the last two glacial cycles, this reconstruction of SAMW properties via equatorial Pacific bulk 𝛿15N may provide the best record of long-term changes in nitrogen dynamics in the subantarctic zone.
4onse project results: quality and costs evaluation of an open and low-cost monitoring network of 30 stations in Sri Lanka
Authors: Strigaro Daniele , Cannata Massimiliano , Ratnayake Rangajeewa , Sudantha Bh , Sahid Imran
Published: March 2021

The 4onse project (Four times Open Non-conventional system for Sensing the Environment) was born by the collaboration between SUPSI and two universities in developing countries namely the University of Moratuwa in Sri Lanka and the Institue of Space Technologies in Pakistan. The activities led to the installation of more than 30 stations in the Deduru Oya basin in Sri Lanka, following the development and testing of a prototype. The rise of technologies for Smart City and the Internet of Things (IoT) makes this project of interest to both the scientific and the private world, also considering the growing concern for environmental and climate issues.

The environmental monitoring system has been designed and developed on the wave of openness, which increasingly pervades not only scientific activity, but also the commercial sectors at different levels. Based on this philosophy, the selected hardware and software technologies have been evaluated in terms of quality, durability and sustainability and are showing very promising results. Unlike conventional systems, where the adoption of closed solutions strongly limits interoperability and data sharing, the designed solution is characterized by a high reproducibility and interoperability, guaranteed by the adoption of open software and standards for the collection and distribution of data. Such a technology can be applied and further developed for monitoring natural and non-natural environments that require low-cost sensor components with a level of quality comparable to conventional systems commonly used. This cost-effective solution is a possible alternative for the implementation of sensor networks in particular in low-income or developing countries in order to manage natural risks or water resources.

The solution consists of three different layers: hardware, server and communication layer. The hardware layer consists of a weather station based on Arduino and sensors measuring environmental variables. This kind of prototype has been validated thanks to the comparison of the time series with the data of an official weather station of the hydro-meteorological network of the Canton Ticino. The second layer is characterized by the server infrastructure that stores the measured data using the istSOS database management system (DBMS), which makes them accessible thanks to the implementation of open standards such as the Sensor Observation Service (SOS) of the Open Geospatial Consortium (OGC). Finally, the communication layer concerns the use of GPRS for the transmission of data from the node to the server that has been optimized in terms of energy and bandwidth consumption in order to guarantee stable and fast communication.

The research project has reached the end of the activities and during this presentation the main results and outputs will be presented.
Case studies on turbulence in different tropopause folds
Authors: Faber Jens , Zülicke Christoph , Gerding Michael , Lübken Franz-Josef
Published: March 2021

Tropopause folds are known as areas of enhanced stratosphere-troposphere exchange. These exchange processes are governed by turbulent mixing in the upper-tropospheric and lower-stratospheric shear zones around the tropopause jet. Since the 1970s, turbulence is also predicted to enhance the ageostrophic circulation around the jet, which leads to the formation of the tropopause fold in an upper-level jet-front system. This claim was recently confirmed by a numerical weather prediction study using the ECMWF-IFS.With our balloon-borne turbulence measuring instrument LITOS, we recently sounded a deep and a medium tropopause fold with astonishing results: in both cases, the strength of turbulence in the lower stratospheric shear layer was three orders of magnitude higher compared to the upper tropospheric shear layer, reaching severe turbulence strengths in the deep-fold case. This has not been reported before, potentially because hardly any observational turbulence study covering both shear layers exists in the literature. In our study, we also quantitatively compare turbulence induced PV changes with PV profiles from the IFS and assess the meteorological situation using further IFS data. Additionally, we investigate mixing processes from tracer-tracer correlations of ozone and water vapour along the flight track of our instrument.
Economic ripple resonance from consecutive weather extremes amplifies consumption losses
Authors: Kuhla Kilian , Willner Sven Norman , Otto Christian , Geiger Tobias , Levemann Anders
Published: March 2021

Weather extremes such as heat waves, tropical cyclones, and river floods are likely to intensify with increasing global mean temperature. In a globally connected supply and trade network such extreme weather events cause economic shocks that may interfere with each other potentially amplifying their overall economic impact.

Here we analyze the economic resonance of consecutive extreme events, that is the overlapping of economic response dynamics of more than one extreme event category both spatially and temporally. In our analysis we focus on the event categories heat stress, river floods, and tropical cyclones. We simulate, via an agent-based anomaly model with more than 7,000 economic agents and 1.8 million connections, the regional (direct) and inter-regional (indirect via supply chains) economic losses and gains for each extreme event category individually as well as for their concurrent occurrence for the next two decades (2020-2039). Thus we compare the outcome of the sum of the three single simulations to the outcome of the concurrent simulation. We show that the global welfare losses due to concurrent weather extremes are increased by more than 18% due to market effects compared to the summation of the losses of each single event category. Overall, this economic resonance yields a non-linearly enhanced price effect, which leads to a stronger economic impact. As well as a highly heterogeneous distribution of the amplification of regional welfare losses among countries.

Our analysis is based on the climate models of the CMIP5 ensemble which have been bias-corrected within the ISIMIP2b project towards an observation-based data set using a trend-preserving method. From these we use RCP2.6 and 6.0 for future climate projections. Thus we compute for each of the three extreme weather event category regional, and sectoral production failure on a daily time scale. Our agent-based dynamic economic loss-propagation model Acclimate then uses these local production failures to compute the immediate response dynamics within the global supply chain as well as the subsequent trade adjustments. The Acclimate model thereby depicts a highly interconnected network of firms and consumers, which maximize their profits by choosing the optimal production level and corresponding upstream demand as well as the optimal distribution of this demand among its suppliers; transport and storage inventories act as buffers for supply shocks. The model accounts for local price changes; supply and demand mismatches are resolved explicitly over time.

Our results suggest that economic impacts of weather extremes are larger than can be derived from conventional single event analysis. Consequently the societal cost of climate change are likely to be underestimated in studies focusing on single extreme categories.
Evaluating Met Office uncoupled and coupled forecasts during the Iceland Greenland Seas Project field campaign in 2018
Authors: Barrell Chris , Renfrew Ian , Abel Steven , Elvidge Andrew , King John
Published: March 2021

During a cold-air outbreak (CAO) a cold polar airmass flows from the frozen land or ice surface, over the marginal ice zone (MIZ), then out over the comparatively warm open ocean. This constitutes a dramatic change in surface temperature, roughness and moisture availability, typically causing rapid change in the atmospheric boundary layer. Consequently, CAOs are associated with a range of severe mesoscale weather phenomena and accurate forecasting is crucial. Over the Nordic Seas CAOs also play a vital role in global ocean circulation, causing densification and sinking of ocean waters that form the headwaters of the Atlantic meridional overturning circulation. 

To tackle the lack of observations during wintertime CAOs and improve scientific understanding in this important region, the Iceland Greenland Seas Project (IGP) undertook an extensive field campaign during February and March 2018. Aiming to characterise the atmospheric forcing and the ocean response, particularly in and around the MIZ, the IGP made coordinated ocean-atmosphere measurements, involving a research vessel, a research aircraft, a meteorological buoy, moorings, sea gliders and floats.  

The work presented here employs these novel observational data to evaluate output from the UK Met Office global operational forecasting system and from a pre-operational coupled ocean-ice-atmosphere system. The Met Office aim to transition to a coupled operational forecast in the coming years, thus verification of model versions in development is essential. Results show that this coupled model’s sea ice is generally more accurate than a persistent field. However, it can also suffer from cold-biased sea surface temperatures around the MIZ, which influences the modelled near-surface meteorology. Both these effects demonstrate the crucial importance of accurate sea ice simulation in coupled model forecasting in the high latitudes. Hence, an ice edge metric is then used to quantify the accuracy of the coupled model MIZ edge at two ocean grid resolutions. 
Towards a high-precision analytical radiation force model for the GPS IIF spacecraft
Authors: Li Grace , Bhattarai Santosh
Published: March 2021

We present the status of our work on producing a new high-precision, physics-based radiation force model for the GPS IIF spacecraft. The details of the spacecraft model, i.e. geometry and surface material properties, are given. The methods used to build the spacecraft model from various information sources are described. Overall, the radiation force model accounts for the direct solar force, the recoil force due to reflected (diffuse and specular) radiation, and also thermal forces (re-radiation and solar panel thermal gradient). The bus component of the radiation force model is computed using ray-tracing techniques. The performance of the new model is compared against one that uses a box-wing spacecraft model. The assumptions and limitations of the modelling are discussed.
Examining and comparing observed and simulated daytime neutral wind and ionospheric drift variations
Authors: Maute Astrid , Harding Brian , Wu Joanne , Triplett Colin , Heelis Rodrick , Forbes Jeffrey M. , Immel Thomas
Published: March 2021

The neutral wind dynamo plays an important role in generating low-latitude ionospheric variability and space weather. The characteristic equatorial ionization anomaly is generated by the daytime equatorial upward drift, which has imprinted on it the variation from upward propagating tides and waves. Observations and modeling studies have indicated large variability of the plasma drift on time scales from days to seasons associated with the wind dynamo at low and middle latitudes. The relationship of the ionospheric drift variability to the neutral wind variations is still not fully understood. The Ionospheric Connection explorer (ICON) mission is designed to focus on the low to middle latitude region and measures key parameters, such as the plasma drift and density and neutral temperatures and winds, to address the question of vertical coupling.

In this presentation, we will focus on the ICON observations and compare to Whole Atmosphere Community Climate Model-Extended (WACCM-X) simulations to examine the daytime low latitude ion drift and neutral wind variations. We investigate the day-to-day and longitudinal variation between concurrent ion drift and neutral wind variations over short time periods to quantify the contribution of the neutral wind in generating the ionospheric drift variations. Employing WACCM-X simulations, we investigate the importance of contributing factors, such as ionospheric conductivities, the geomagnetic main field, magnetosphere-ionosphere coupling, and the neutral wind, in generating the observed ionospheric drift variations. While we focus in this study on field line integrated ionospheric current density due to electric field/drift and neutral wind, we conclude by discussing our results in a more general context.
Towards tide gauges selection for model-based hydrodynamic leveling connections; with application to assess the potential impact on the quality of the European Vertical Reference Frame
Authors: Afrasteh Yosra , Slobbe Cornelis , Verlaan Martin , Sacher Martina , Klees Roland , Guarneri Henrique , Keyzer Lennart , Pietrzak Julie , Snellen Mirjam , Zijl Firmijn
Published: March 2021

Model-based hydrodynamic leveling allows transferring heights between tide gauges by means of model-derived mean water level (MWL) differences between them. In this study, we aim to exploit the technique to improve the quality of the European Vertical Reference Frame (EVRF). In doing so, the candidate tide gauges must fulfill two criteria. First, they must be connected to the Unified European Leveling Network (UELN). Second, the hydrodynamic model to be used should be capable of resolving the local MWL at the tide gauge locations. The latter can be very challenging as some tide gauges are located in areas with complicated hydrodynamic processes. To identify which tide gauges have the largest impact on the quality of the EVRF, we conducted geodetic network analyzes. Here we used all tide gauges within 10 km of UELN height markers. Moreover, we assumed to have access to a hydrodynamic model covering all European seas, or alternatively regional models for separate basins, providing the MWLs with uniform precision. Our results indicate a reduction of the mean propagated standard deviation of the adjusted heights between 20% to 40% compared to the UELN-only solution. The magnitude of the improvement depends on the setup of the experiment and the selected noise level for model-derived MWL differences. Detailed analysis shows that we already obtain a significant improvement (>20%) by adding only a limited number of hydrodynamic leveling connections. Moreover, we found that the tide gauges located in the countries with the most UELN height markers are most profitable in terms of improvement. The impact hardly depends on the tide gauges' geographic location, which shows the method's freedom and flexibility in selecting the tide gauges.
A tentative attempt to better trace the late Pleistocene oxygen cycle
Authors: Yang Ji-Woong , Extier Thomas , Kölling Martin , Landais Amaëlle , Leloup Gaëlle , Paillard Didier , Brandon Margaux , Blunier Thomas
Published: March 2021

Atmospheric abundance of oxygen (O2) has been co-evolved with different aspects of the Earth system since appearance of oxygenic photosynthesis by cyanobacteria around 2.4 109 years before present (Ga). Therefore, much attention has been paid to understand the changes in O2 and the underlying mechanisms over the Earth’s history. The pioneering work by Stolper et al. (2016) revealed the long-term decreasing trend of O2 mixing ratios over the last 800,000 years using the ice-core composite record of molar ratios of O2 and nitrogen (δ(O2/N2)), implying a slight imbalance between sources and sinks. Over geological time scale, O2 is mainly controlled by burial and oxidation of organic carbon and pyrite, but also by oxidation of volcanic gases and sedimentary rocks. Nevertheless, the O2 cycle of the late Pleistocene has not been well understood, partly due to the lack of knowledge about the individual sources and sinks. Since then, Kölling et al. (2019) proposed a simple model to estimate the O2 release/uptake fluxes due to the pyrite burial/oxidation that predicts up to ~70% of the O2 decrease of the last 800,000 years could be explained by pyrite burial/oxidation.

Building on this, we present here our preliminary, tentative attempt for reconstruction of the net organic carbon burial flux over the last 800,000 years by combining available information (including new δ(O2/N2) data) and assuming constant O2 fluxes associated with volcanic outgassing and rock weathering. The long-term organic carbon burial flux trend obtained with our new calculations is similar to the global ocean δ13C records but also to simulations using a conceptual carbon cycle model (Paillard, 2017). These results partly support the geomorphological hypothesis that the major sea-level drops during the earlier period of the last 800,000 years lead to enhanced organic carbon burial, and that significant changes in the net organic carbon happen around Marine Isotopic Stage (MIS) 13. In addition, we present the long-term decreasing trend of the global biosphere productivity, or gross photosynthetic O2 flux, reconstructed from new measurements of triple-isotope composition of atmospheric O2 trapped in ice cores. As the largest O2 flux, the observed decrease in gross photosynthesis requires to be compensated by parallel reduction of global ecosystem respiration.
Displacement monitoring using multi-technique antenna calibrations in processing GNSS data from multi-frequency low-cost receivers
Authors: Gatti Andrea , Tagliaferro Giulio , Realini Eugenio
Published: March 2021

In the framework of the EU founded GIMS-Project (Geodetic Integrated Monitoring System), a low-cost solution for detecting and measuring ground movements have been developed (https://www.gims-project.eu/). In particular, our focus was the improvement of processing techniques of multi-constellation GNSS data from low-cost devices, culminated in the development of improved algorithms implemented now in the goGPS open-source software (https://gogps-project.github.io). The goGPS engine has been used to analyse the motion of two different landslides in Slovenia. It is currently successfully employed to monitor, in near real-time, numerous landslides and structures.

During the last year, we developed an advanced technique to improve the on-site calibration of the low-cost antennas that allows a drastic improvement of the stability of sub-daily coordinates. This approach is based on iterative steps designed to filter the multipath affecting phase measurements and the phase center variation of the antennas.

A first solution using more than 10 days of data is computed with the goal of retrieving phase residuals. Then these residuals are filtered using a combination of Zernike polynomials interpolation and multi-resolution gridding in order to obtain hemi-spherical maps able to correct the observations of longer periods. A final solution is finally obtained applying the stored corrections.

Eventually the procedure can be iterated to reach convergence and maps can be updated after environmental changes.

By using these maps in a multi-constellation environment, the monitoring of displacements is feasible with low-cost receivers (single and multi-frequencies) even in challenging conditions. The accuracy improvements are higher than 50% with respect to a scenario without maps.

In this work, the processing procedure of low-cost receivers is presented with examples of successful monitoring experiences.
36Cl exposure dating of post-glacial features along the Mt Vettore Fault (Central Apennines, Italy) constraining fault slip rate and last glacial advance.
Authors: Pousse-Beltran Lea , Benedetti Lucilla , Fleury Jules , Boncio Paolo , Guillou Valery , Pace Bruno , Rizza Magali , Puliti Irene , Team Aster
Published: March 2021

In the Central Apennines (Italy), up to now, no absolute dating directly based on the moraines has been carried out to constrain glacial oscillation. However, climatic constrains are often used in the Central Apennine to estimate long term (> 10 ka) fault slip rate. In addition slip rate assessments based on offset morphotectonic markers on the main branches of fault systems and encompassing several seismic cycles (> 10 ka) are sparse. This is particularly true for the Monte Vettore-Monte Bove fault system which triggered the 2016-2017 seismic sequence. We thus provide new assessment for the vertical slip rates along the Mt Vettore-Mt Bove fault system.  Offset measurements were made using a 5-cm resolution DEM obtained through a drone survey and constrain a fault scarp height of 15.5 ± 1.4 m and a cumulative offset of 32-40.5 m. Samples were collected from the Valle Lunga terminal moraine at 1710 m asl and yield 36Cl exposure ages of 12.7 + 2.2/-1.9 ka while the flat, abraded surface located on top of the tectonic scarp yield 36Cl exposure ages of 23.4 + 5.3/-4.3 ka. Assuming the offset started to accumulate when climate conditions allow its preservation, thus once the surface was abandoned, we constrain a vertical slip rate of 1.2 ± 0.2 mm/yr along the master branch of the Mt Vettore normal fault.  This rate is higher than the ones previously obtained from trenches along secondary splays of the Mt Vettore-Mt Bove and on the Norcia fault systems. Besides, the yielded chronology for the last glacial maximum in that area at ~23 ka is in good agreement with the timing previously proposed for the LGM in the Apennines.
Using airborne lidar and weather radar measurements to characterize the interplay between aerosol and shallow marine trade wind clouds
Authors: Ewald Florian , Groß Silke , Wirth Martin , Hagen Martin , Gutleben Manuel
Published: March 2021

The interaction of aerosol, clouds, and water vapor is still a major source of uncertainty in projections of Earth’s future climate. Especially in the trades, the response of shallow marine trade wind convection to external forcings is poorly understood. These low-level clouds have an important cooling effect on surface temperatures, while their amount and height are directly influenced by the radiative cooling by aerosols and water vapor aloft. Furthermore, there is evidence that aerosols can modify the microphysical properties (e.g., by glaciation) and the precipitation formation inside these clouds while water vapor above the trade inversion influences the atmospheric stability in which they form. Due to the small horizontal scale of these clouds, the vertical separation of atmospheric layers, and the temporal evolution of precipitation, the observation of this interplay by geostationary satellites is scarce.

To alleviate this observational data gap over the tropical North-Atlantic region, airborne lidar and cloud radar measurements were performed in the vicinity of Barbados and complemented with dedicated weather radar measurements during the EUREC4A campaign in February 2020. Aerosol properties and the vertical water vapor profile were characterized with simultaneous high spectral resolution and differential absorption measurements using the WALES lidar onboard the German research aircraft HALO. On the same platform, the vertical cloud extent and the presence of precipitation were sampled with the high-power Ka-band cloud radar HAMP MIRA. To capture the temporal evolution of precipitation patterns, these measurements were complemented with measurements of the C-band polarimetric weather radar POLDIRAD which was installed on the windward side of Barbados. During EUREC4A, measurements flights were conducted in high and low aerosol loads to sample its influence on the marine trade wind convection.

This presentation will briefly introduce the instrumentation, data processing, and availability and give an overview of gained insights and ongoing studies. By means of case studies, we will give first impressions of the complementary nature of the collocated, highly resolved airborne measurements and the POLDIRAD measurements which provide the horizontal context and temporal evolution of the precipitation formation. By combining the cross-sectional snapshots with the temporal evolution of the precipitation pattern we will provide a detailed insight into the interplay between the aerosol and water vapor layer and the precipitation formation in the shallow marine trade wind convection.
Four years of InSAR time series analysis reveals an unprecedent inventory of active DSGSD in the Western Alps
Authors: André Pauline , Doin Marie-Pierre , Mathey Marguerite , Zerathe Swann , Vassallo Riccardo , Baize Stéphane
Published: March 2021

Based on geomorphological criteria, large-scale slow gravitational deformation affecting entire mountain flank, often being referred as Deep-Seated Gravitational Slope Deformation (DSGSD), have been shown to affect most of the reliefs worldwide. For instance in the European Alps, these deformation patterns were identified in several areas such as the Aosta Valley (Martinotti et al., 2011) or the Mercantour massif (Jomard, 2006). DSGSD inventories based on visual interpretation of scarps and field mapping were then compiled (e.g. Crosta et al., 2013) revealing the widespread occurrence of DSGSD. However, many aspects of these large-scale gravitational processes remain unclear and in particular their present-day activity and temporal evolution remain largely unknown.

The present study aims at characterizing the spatial extent of DSGSD, and their velocity, at the scale of Western Alps through InSAR time series analysis using NSBAS processing chain (Doin et al., 2001). We used the whole SAR Sentinel-1 archive, between 2014 and 2018, with an acquisition every 6 days, on an ascending track. The processing was adapted to fit the specific conditions of the Alps (seasonal snow cover, strong local relief, vegetation and strong atmospheric heterogeneities). In particular we implemented a correction using the ERA 5 weather model and we used snow masks in winter allowing to select long temporal baseline interferograms with as little snow as possible. As we specifically aim to study deformation patterns at the scale of valley flanks, an average high-pass filter on moving subwindows has been applied to the interferograms prior to the implementation of time-serie inversions. This step strongly reduced the impact of residual atmospheric delays.

The resulting velocity map in the line of sight (LOS) of the satellite reveals ubiquitous gravitational deformation patterns over the whole Western Alps, with localized patches of moving slopes showing sharp discontinuities with stable surrounding areas. We used radar geometry and InSAR measurement quality factors as indicators to identify the most trusted areas and to extract an inventory of potential DSGSD with their spatial extent. Doing so, we identified more than two thousands slowly deforming areas characterized by LOS velocities from 4 to 20 mm/year. We then compared the geometries of our “InSAR-detected-deforming-slopes” with previously published DSGSD inventories. Good agreements were found for example in the Aosta valley where most of the deforming areas from our velocity map are falling into the DSGSD outlines of Crosta et al. (2013). Currently, we continue to investigate the potential of this large-scale velocity map for DSGSD understanding and we plan to use artificial intelligence to search for possible generic properties between the detected sites.
Bacterial abundance, growth and community composition in oligotrophic, metal-rich running waters of Southern New Caledonia
Authors: Motegi Chiaki , Bettarel Yvan , Dufour Aurélie , Mari Xavier , Migon Christophe , Rochelle-Newall Emma , Pringault Olivier , Torréton Jean-Pascal , Weinbauer Markus
Published: March 2021

The basic bacterial ecology and diversity was investigated in five running water systems of Southern New Caledonia. These running waters were characterized by potential P-limitation and high concentrations of Ni, Fe, Mn, Cr and Co. The low concentrations of dissolved organic carbon, bacterial and viral abundance, bacterial production and growth efficiency support the characterization of the running waters as oligotroph to ultraoligotroph. Despite these similarities, there were strong differences (<50% similarity) in bacterial community composition between some habitats based on 16S rRNA gene and denaturing gradient gel electrophoresis (DGGE) fingerprints. The high coverage of sequenced DGGE bands found for Betaproteobacteria is typical for freshwater systems, however, we found also a strong representation of Gammaproteobacteria. Indeed the three bands found at all stations were related to Limnohabitans (Comamonadaceae) and Alteromonadaceae. Strong differences were also found between the free-living and the attached bacterial fraction with Gammaproteobacteria dominating in two systems. A higher representation of Gammaproteobacteria seems typical for metal-rich freshwater habitats. Consistent with fresh water habitats, majority of phylotypes detected in the sediment was affiliated to proteobacteria. Also, none of the sequences showed a 100% identity with data bases, and 10 of the 22 and 2 of the 23 sequences had similarities higher than 97% in the freshwater and sediment. This could indicate specific adaptations of the community composition either due to the high metal concentrations or due to the geographical isolation of the New Caledonia. 
A global observation-based dataset of sub-daily precipitation indices
Authors: Pritchard David , Lewis Elizabeth , Fowler Hayley , Blenkinsop Stephen , Whitford Anna
Published: March 2021

Short duration precipitation extremes can lead to severe flash flooding and destructive landslides. Yet many gaps remain in our understanding of these acute precipitation events, partly due to the lack of accessible and high quality sub-daily observational datasets available to researchers. To address this problem, the INTENSE project (leading the GEWEX Hydroclimatology Panel Cross-Cutting Project on Sub-Daily Extremes) has coordinated a major international effort to collate sub-daily precipitation observations from around the world. The resulting Global Sub-Daily Rainfall (GSDR) dataset contains hourly precipitation records from over 20,000 gauges globally. The quality of the raw data underpinning the GSDR dataset is variable, so an automated and wide-ranging quality control procedure has been developed and applied to the records. To facilitate research and other applications of the dataset, we have defined and calculated a novel set of sub-daily precipitation indices. These indices complement and extend the ETCCDI daily precipitation indices by characterising key aspects of shorter duration precipitation variability, including intensity, duration and frequency properties. Project partners and other collaborators continue to augment the resulting indices database by performing the calculations on their own observations and sharing these with the INTENSE project, with new contributors always welcome. This combined effort has led to an extensive observation-based climatology of various sub-daily precipitation characteristics (including extremes) across large parts of the world. These indices will be publicly available for as many gauges as possible, alongside a gridded dataset that also incorporates indices calculated for additional restricted-access gauge records.
The geology of Yelcho Station: a new high-resolution geological map at northwestern Antarctic Peninsula
Authors: Jara Wuidad , Bastias Joaquin , Jaña Ricardo , Leppe Marcelo
Published: March 2021

Yelcho Station is set on Doumer Island located in the southernmost section of Gerlache Strait between Anvers and Wienke Islands at the northwestern region of Antarctic Peninsula. This area is dominated by plutonic and volcanic deposits associated with the active margin developed during the Mesozoic and Cenozoic in the Antarctic Peninsula (e.g. Leat et al., 1995). Although Yelcho Station has been intensively visited since a few decades, the outcropping rocks have not been studied in detail. Furthermore, this location has hosted relevant contributions in the environmental and ecological sciences. We will present a detailed map (1:500) of the geological units outcropping in Yelcho Station based in fieldwork observations, which will be combined with drone and satellite images. Additionally, remote sensing spectral studies will be developed to support the geological mapping. This work will help to establish a geological baseline, which may serve for future studies in the area of Yelcho Station. This contribution will be a detailed geological study in the Antarctic Peninsula, which will also enhance our understanding of the geological units outcropping in Gerlache Strait. This material will also serve as an educational and outreach information for the polar community.

Leat et al. (1995). Geological Magazine 132 (4), 399-412 (DOI: 10.1017/S0016756800021464).
Crowdsourced Landslide Tracking – Lessons from Field Experiences of Landslide Tracker Mobile App
Authors: Hariharan Balaji , Guntha Ramesh
Published: March 2021

With the Landslide Tracker mobile app's launch to track landslides through a crowdsourcing model during the monsoon season of 2020, we learned several important lessons that may help us improve the data quality, volunteer participation, and participation from institutions. The 'Landslide Tracker' mobile application allows tracking the landslides and details such as GPS location, date & time of occurrence, images, type, material, size, impact, area, geology, geomorphology, and comments. This app is available on Google Play Store for free, and at http://landslides.amrita.edu, with software conceived and developed by Amrita University in the context of the UK NERC/FCDO funded LANDSLIP research project (http://www.landslip.org/). The Landslide tracker app was released during the 2020 monsoon season, and more than 250 landslides were recorded through the app across India and the world.

Due to the nature of crowdsourcing, we have seen test entries, duplicate entries, entries with apparent mistakes such as the wrong location. In many cases, these entries were deleted by the administrator through proactive verification. To sustain the removal of invalid entries with continued usage, we can allow users to mark a landslide for verification. The administrator can remove invalid entries or approach the original contributor to update the data with minimum effort. Currently it takes under three minutes to record a landslide. To reduce the time further, it is requested to make a single page form to record date, location, images and few questions. To improve volunteer participation for contributing and validating landslide entries, we can implement digital rewards such as points, badges, titles, leader boards, etc. Additionally, allow users to like, comment, and share the landslide entries to improve the engagement. To improve the participation of universities, disaster management authorities, district authorities, and other governmental and non-governmental agencies for contributing and using landslide information, we can implement the institutional management functionality. It allows the institution to configure the staff and manager user. The manager can review, update, delete entries from the team, get reports on the contribution of the staff, and download and share the landslides contributed by the whole institution.
Large-scale Structure and Turbulence Transport in the Young Solar Wind – Comparison of Parker Solar Probe Observations with a Global 3D Reynolds-averaged MHD Model
Authors: Chhiber Rohit , Usmanov Arcadi , Matthaeus William , Goldstein Melvyn , Bandyopadhyay Riddhi
Published: March 2021

Simulation results from a global magnetohydrodynamic model of the solar corona and the solar wind are compared with Parker Solar Probe's (PSP) observations during its first several orbits. The fully three-dimensional model (Usmanov et al., 2018, ApJ, 865, 25) is based on Reynolds-averaged mean-flow equations coupled with turbulence transport equations. The model accounts for effects of electron heat conduction, Coulomb collisions, Reynolds stresses, and heating of protons and electrons via nonlinear turbulent cascade. Turbulence transport equations for turbulence energy, cross helicity, and correlation length are solved concurrently with the mean-flow equations. We specify boundary conditions at the coronal base using solar synoptic magnetograms and calculate plasma, magnetic field, and turbulence parameters along the PSP trajectory. We also accumulate data from all orbits considered, to obtain the trends observed as a function of heliocentric distance. Comparison of simulation results with PSP data show general agreement. Finally, we generate synthetic fluctuations constrained by the local rms turbulence amplitude given by the model, and compare properties of this synthetic turbulence with PSP observations.