bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling biodegradation and growth of microorganisms via particle tracking
Authors: Dawi Malik , Sanchez-Vila Xavier
Published: March 2022

Biologically mediated degradation of organic compounds is heavily non-linear. When an organic compound is degraded part of the carbon is present in the form of metabolite while a fraction of it is used to increase the biomass, capable then to enhance the degradation process. The rate of biomass growth is usually modeled with the experimentally derived Monod equation, so that it is proportional to the actual existing biomass multiplied by a non-linear factor in terms of available organic matter. The non-linearity in the degradation equation implies a strong difficulty in directly implementing a numerical solution within a Lagrangian framework. Thus, numerical solutions have traditionally been sought in an Eulerian framework.

Here we pursue a fully Lagrangian solution to the problem. First, the Monod empirical equation is derived from a two-step reaction ( B+C → k1 BC → k2 B +  ΔB + P); while the approach is less general to other derivations existing in the literature, it allows two things: (1) providing some physical meaning to the actual parameters in Monod equation, and more interestingly (2) formulate a methodology for the solution of the degradation equation incorporating Monod kinetics by means of a particle tracking formulation. For the latter purpose, reactants and biomass are represented by particles, and their location at any given time is represented by a kernel that includes the uncertainty in the actual physical location. By solving the reaction equation in a kernel framework, we can reproduce the Monod kinetics and, as a particular result in the case of no biomass growth is allowed, the Michaelis–Menten kinetics. We show how the method is successfully applied to reproduce two studies of microbially induced degradation. First, the observed kinetics of Pseudomonas putida F1 in batch reactors while growing on benzene, toluene and phenol, and second, the column study of carbon tetrachloride biodegradation by the denitrifying bacterium Pseudomonas Stutzeri KC.

 
Risk Analysis of Algal Blooms Using the Conditional Copula Model
Authors: Cho Hemie , Yu Jae-Ung , Kim Jinyoung , Kwon Hyun-Han
Published: March 2022

In Korea, algal blooms are repeated every year in the four major rivers. Especially, the frequency and duration of algal blooms have increased due to climate change (increase in the atmosphere and water temperature) and environmental changes (river development projects and weir construction), which has led to the development of related research. However, it is still difficult to elucidate the cause of algal blooms because of a complicated mechanism. In this study, the concentration of Chlorophyll-a was selected as an indicator of algae occurrence, and representative hydrometeorological factors affecting the algal phenomenon were selected. Then, the optimal marginal distribution for each variable was found. The risk of algal blooms was analyzed through bivariate copula analysis by identifying the relationship between the influencing factors and the concentration of Chlorophyll-a. As a result, it was possible to identify the factors that had the most significant influence on the occurrence of algal blooms. Further, this study will employ the Vine Copula function to improve the complex relationship between variables in the context of multivariate modeling.
Recent Advances in Deep Learning for Spatio-Temporal Drought Monitoring, Forecasting and Model Understanding
Authors: González-Calabuig María , Cortés-Andrés Jordi , Fernández-Torres Miguel-Ángel , Camps-Valls Gustau
Published: March 2022

Droughts constitute one of the costliest natural hazards and have seriously destructive effects on the ecological environment, agricultural production and socio-economic conditions. Their elusive and subjective definition, due to the complex physical, chemical and biological processes of the Earth system they involve, makes their management an arduous challenge to researchers, as well as decision and policy makers. We present here our most recent advances in machine learning models in three complementary lines of research about droughts: monitoring, forecasting and understanding. While monitoring or detection is about gaining the time series of drought maps and discovering underlying patterns and correlations, forecasting or prediction is to anticipate future droughts. Last but not least, understanding or explaining models by means of expert-comprehensible representations is equally important as accurately addressing these tasks, especially for their deployment in real scenarios. Thanks to the emergence and success of deep learning, all of these tasks can be tackled by the design of spatio-temporal data-driven approaches built on the basis of climate variables (soil moisture, precipitation, temperature, vegetation health, etc.) and/or satellite imagery. The possibilities are endless, from the design of convolutional architectures and attention mechanisms to the use of generative models such as Normalizing Flows (NFs) or Generative Adversarial Networks (GANs), trained both in a supervised and unsupervised manner, among others. Different application examples in Europe from 2003 onwards are provided, with the aim of reflecting on the possibilities of the strategies proposed, and also of foreseeing alternatives and future lines of development. For that purpose, we make use of several mesoscale (1 km) spatial and 8 days temporal resolution variables included in the Earth System Data Cube (ESDC) [Mahecha et al., 2020] for drought detection, while high resolution (20 m, 5 days) Sentinel-2 data cubes, extracted from the extreme summer track in EarthNet2021 [Requena-Mesa et al., 2021], are considered for forecasting.

 

References

Mahecha, M. D., Gans, F., Brandt, G., Christiansen, R., Cornell, S. E., Fomferra, N., ... & Reichstein, M. (2020). Earth system data cubes unravel global multivariate dynamics. Earth System Dynamics, 11(1), 201-234.

Requena-Mesa, C., Benson, V., Reichstein, M., Runge, J., & Denzler, J. (2021). EarthNet2021: A large-scale dataset and challenge for Earth surface forecasting as a guided video prediction task. In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (pp. 1132-1142).
Selection of CMIP6 Global Climate Models for long-term hydrological projections 
Authors: Nguyen Thi Huong , Kim Ho-Jun , Jung Min-Kyu , Kwon Hyun-Han
Published: March 2022

Selection of a suitable Global Climate Model (GCM) in hydrological research for basin-scale of monsoon affected regions under future climate projection scenarios is a great necessity. This study comprehensively evaluated the suitability of 25 available GCMs issued of  Coupled Model Intercomparison Project 6 (CMIP6) to choose the best performing GCMs in precipitation simulating skill over the whole main River Basin System in South Korea for the historical period of 1973–2014. Bilinear interpolation method was used for mapping the grid resolution of the simulated GCMs precipitation and observed precipitation with a 0.1250 x 0.1250 resolution. Where, the observed monthly precipitation at 56 automated weather stations from 1973 to 2014 were derived from the Korea Meteorological Administration (KMA). Multi-Criteria Decision Making (MCDM) approach based on four spatial metrics, Cramer’s V, Goodman-Kruskal (GK) Lambda, Mapcurves and TheilU were proposed to compare the simulated GCMs precipitation with the observed precipitation. To calculate the overall ranking of the GCMs and identify the best performing GCMs, this study applied Jenks Natural Break classification based on the Compromise Programming index. The results indicated that: 1) The GCMs performance was different with different spatial indices with the most suitable of GCMs ranking for each watershed. 2) The best performing GCMs well simulated the annual mean precipitation with a bias of less than 15% for southwestern watersheds and higher biases (30-50%) for remaining watersheds. 3) Majority of CMIP6 GCMs could be capture trends and the spatial distribution of annual, seasonal precipitation over South Korea. However, the result was also found that most GCMs underestimated summer precipitation and overestimated spring precipitation. Therefore, the selected GCMs with corrected biases can be usefully employed for analyzing future changes of hydrological pattern associated with climate change projections.

Keywords: Global Climate Models (GCMs), CMIP6, Bilinear interpolation, Multi-Criteria Decision Making, Jenks Natural Break classification.
Atmospheric drivers of Greenland ice sheet surface energy and mass balance changes as a function of elevation and circulation patterns
Authors: Silva Tiago , Abermann Jakob , Noël Brice , Shahi Sonika , van der Schot Jorrit , Schöner Wolfgang
Published: March 2022

Recent Greenland Ice Sheet (GrIS) surface mass loss has been attributed to the expansion of the bare ice area following the upward migration of the snowline along with persistent blocking systems. Given the temporal fluctuations and spatial heterogeneity of the ablation zone, the local impacts of atmospheric drivers on the GrIS surface energy and mass balance at different elevations and under various atmospheric circulation patterns remain poorly known.

Based on the 1959-2020 period, we present a new indicator of the North Atlantic influence over Greenland (NAG) as the combination of the North Atlantic Oscillation Index (NAO), the Greenland Blocking Index (GBI) and the vertically integrated water vapor over the GrIS. We explore the NAG monthly frequency and the inter-annual evolution along with large-scale spatial anomalies. With the support of a high-resolution regional climate model (RACMO2.3p2), we investigate the influence of spatio-temporal NAG fluctuations on atmospheric drivers, surface energy and mass balance fluxes, that triggered the expansion of the ablation zone to higher elevations. Finally, we assess NAG performance by comparing its results with NAO and GBI alone.
 Radial evolution of the key solar wind parameters according to the Parker Solar Probe and other missions
Authors: Antsiferova Uliana , Khabarova Olga
Published: March 2022

Knowing the temporal and spatial behavior of the main plasma parameters in the solar wind is important because of both an academic interest and the necessity to build theoretical models. Meanwhile, the solar wind characteristics are available with good accuracy only from in situspacecraft observations. There are a very limited number of studies that analyzed the radial evolution of the interplanetary magnetic field, the speed, the density, and the temperature of the solar wind. Previously, data from missions carried out in the 1970s were used for these purposes. Meanwhile, none of them approached the Sun closer than ~0.3 AU, and the information available did not allow describing the processes occurring near the solar corona. The launch of the Parker Solar Probe mission has opened up vast opportunities for studying the solar wind, starting from distances of the order of the Alfven radius. At the moment, Parker Solar Probe data are available with approaches to the Sun up to 0.08 AU.

An analysis of data obtained from Parker Solar Probe and Helios 2 (up to 1 AU), and from IMP8 and Voyager 1 (further from the Earth's orbit and up to 7 AU) was performed. The dependencies of the interplanetary magnetic field, the temperature, the speed, and the density of the solar wind on heliocentric distance are revealed and their typical profiles are analyzed. The nature of deviations of observed values from theoretical expectations is discussed. A particular attention is paid to the comparison of the results from the Parker Solar Probe and Helios missions.
Spatio-temporal patterns of fluid-driven aseismic slip transients: implications to seismic swarms
Authors: Sáez Alexis , Lecampion Brice
Published: March 2022

Seismic swarms are often interpreted to be driven by natural fluid pressurization in the Earth’s crust, when seismicity is observed to spread away from a common origin and follows approximately a square-root-of-time pattern of growth. On the other hand, a growing body of literature suggests that aseismic fault slip seems to be a frequent result of fluid injections and may trigger seismicity due to the stress transfer of quasi-statically propagating ruptures in critically stressed regions. Although in some conditions a nominal pore pressure perturbation front may evolve proportionally to the square root of time, much less is known about the temporal patterns of fluid-driven aseismic slip fronts. The latter hinders efforts to distinguish whether some seismic swarms are driven by aseismic slip episodes or not. In this contribution, we provide an extensive set of physics-based solutions that describes the evolution of fluid-driven aseismic slip fronts for a wide range of conditions in terms of in-situ stress state and fluid flow. Our solutions show that fluid-driven aseismic slip fronts may result in many different patterns of propagation, depending on the characteristics of the fluid source (e.g., constant-pressure source, constant-rate source, among others) and also if simplified 2-D or fully 3-D elasticity is considered. Other parameters such as the initial stress state and fault hydraulic properties are also relevant in the propagation of the slip fronts. Our family of solutions includes cases in which aseismic slip fronts propagate following a square-root-of-time dependence, a linear expansion with time, power laws of time with exponents lower than ½, and some other more complex evolutions. These results are based on the model of a fluid-driven frictional shear crack that propagates on a planar fault interface characterized by a constant friction coefficient and a constant permeability, embedded in an infinite linearly elastic medium with an initially uniform state of stress. Although the basic assumptions of the model are simple, it results in a significant amount of complexity in terms of possible spatio-temporal patterns of rupture propagation. Since a constant friction coefficient corresponds to a fault interface with zero fracture energy, we show by analyzing the rupture-front energy balance of fluid-driven aseismic slip transients with non-zero fracture energy, that an asymptotic regime in which the fracture energy is negligible is always ultimately reached. This regime is approached asymptotically when the rupture has propagated over a distance larger than a characteristic length-scale depending on the frictional fracture energy and the in-situ stress state. We expect our results to provide a simple means to interpret observations of seismic swarms for which fluid-driven aseismic slip transients are thought to be a relevant mechanism in the triggering of seismicity.
Using MODIS thermal data for mapping and monitoring of a massive multi-year flooding event in South Sudan for humanitarian response and decision making 
Authors: Boeck Sebastian , Bonifacio Rogerio , Pozzi Lia , Bockowska Paulina
Published: March 2022

A period of exceptionally heavy rainfall across many parts of East Africa from late 2019 to early 2020, followed by above average rainfalls throughout 2020, triggered devastating floods destroying livelihoods and displacing millions of people across the region. South Sudan was hard-hit by the episode of increased rainfall, not only because it triggered severe pluvial and riverine flooding within the country from late 2019 onwards, but also because it led to a more persistent rise in East African lake levels, with subsequent impacts still felt today. 

The peculiarities of South Sudan’s topography, the composition of soils, as well as its huge, mostly inaccessible wetlands, make hydrological modelling and flood mapping a non-trivial task. Furthermore, due to climate and other ecological factors, water surfaces are often obscured by vegetation and patches of floating plant debris, which can lead to an under detection of the flood extent, when optical and radar earth observation satellite data is employed. To overcome this limitation, land-surface temperature data is used and combined with various other satellite data streams to monitor flood and wetland dynamics at multiple spatial and temporal scales. Using historical data, the uniqueness of the current event in recent decades is highlighted and put into context. The insights gained from the analysis not only help deepen the understanding of an ecosystem of regional importance, but also directly support humanitarian decision making and foster efficient allocation of resources. 
Particle Energisation in Collapsing Magnetic Traps 
Authors: Mowbray Kate , Neukirch Thomas
Published: March 2022

Investigating the motion of charged particles in time- and space-dependent electromagnetic fields is central to many areas of space and astrophysical plasmas. Here we present results of studying the energy changes of particle orbits that are trapped in inhomogeneous magnetic fields with rapidly shortening field lines. These so-called collapsing magnetic trap (CMT) models can be useful for explaining the acceleration of particles below the reconnection region in a solar flare. For both 2D and 3D CMT models (e.g. Giuliani et al. 2005; Grady & Neukirch, 2009), betatron acceleration was considered to be the dominant energisation mechanism. We present new results that have been obtained using an improved version of the 3D CMT model by Grady and Neukirch (2009). Our investigations show that a sizeable portion of particle orbits can gain a significant amount of energy that is not explained by the betatron effect. The other mechanism at play appears to be Fermi acceleration at loop tops, where the particle passes through the region of field that is collapsing the most rapidly. 

We show that the particles that experience this effect the most have initial positions that are related to specific regions of the magnetic field model and it is these particle orbits whose energy gains are not adequately explained by betatron acceleration alone. In fact, some particle orbits seem to gain energy almost entirely as a result of this Fermi acceleration. One can also show that for suitable initial conditions the same effect can be seen in the 2D CMT model given by Giuliani et al. (2005). This updated understanding of the systems at play for particle acceleration in a CMT can, for example, inform any changes made to future CMT models by accounting for the large number of particles that see energy gains due to Fermi acceleration. 

Giuliani, P. et al., ApJ 635, 636

Grady, K. & Neukirch, T., A&A 508, 1461 

 
North Atlantic CO2 sink variability revealed by the Go-Ship A25-OVIDE section
Authors: López Mozos Marta , Velo Antón , Fontela Marcos , de la Paz Mercedes , Carracedo Lidia , Fajar Noelia , García-Ibáñez Maria Isabel , Padín Xose Antonio , Desbruyères Damien , Mercier Herlé , Lherminier Pascale , Pérez Fiz F
Published: March 2022

About 30% of the carbon dioxide derived from human activities (CANTH) has been absorbed by the ocean (DeVries, 2014; Gruber et al., 2019; Friedlingstein et al., 2021), with the North Atlantic (NA) being one of the largest CANTH sinks per unit area (Khatiwala et al., 2013; Sabine et al., 2004). In the NA, oceanic CANTH uptake strongly relies on the meridional overturning circulation and the associated regional winter deep convection. In fact, the formation and deep spreading of Labrador Sea Water stands as a critical CANTH gateway to intermediate and abyssal depths. The NA CANTH uptake has fluctuated over the years according to changes in the North Atlantic Oscillation. Biennial observation of the marine carbonate system along the Go-Ship A25-OVIDE section has allowed us assessing the decadal and interannual variability of the CANTH storage in the subpolar NA from 2002 to 2021. In this study, we investigate 1) the trend of CANTH and 2) the relationship between the CANTH saturation, the apparent oxygen utilization, and the ventilation of the water masses between the A25-OVIDE section and the Greenland-Iceland-Scotland sills during 2002-2021. We divided the A25-OVIDE section into three main basins (Irminger, Iceland, and Eastern NA). Our results show that the Irminger Basin presents a more homogenous CANTH profile and higher CANTH saturation values at depth than the other two basins, which is related to the pronounced convective activity in the Irminger Basin. In contrast, the Eastern NA Basin has higher CANTH values at the surface due to its higher surface temperature, but its deep water masses show the lowest CANTH values since they are the less ventilated in the section. Our analysis also reveals that, overall, the NA CANTH storage has increased during 2002-2021, but varied according to the ventilation changes. While the Eastern NA water masses experienced a relatively constant, although shallower, average ventilation, the Irminger and Iceland Basins underwent a less steady CANTH uptake pattern characterized by alternating periods of strong and weak CANTH storage.
From Field Application to Publication: An end-to-end Solution for FAIR Geoscience Data
Authors: Theile Moritz , Noble Wayne , Beucher Romain , McMillan Malcolm , Boone Samuel , Kohlmann Fabian
Published: March 2022

In this abstract we introduce a suite of free applications to produce FAIR consistent, clean and easily available geoscience data for research and industry alike. 

Creation of data starts with sample collection in the field and the assigning of an unique global IGSN sample identifier to samples, these samples are stored along with any subsequent  analytical data in our fine-grained and detailed geochemical data models allowing visualising and publishing acquired datasets. This unique solution has been developed by Lithodat Pty Ltd in conjunction with the AuScope Geochemical Network (AGN), Australian geochemical laboratories and can be accessed by the public on the AusGeochem web platform. 

Using our fully integrated field application users can enter and store all sample details on-the-fly during field collection, the data will be stored in the user's private data collection. Once the researchers return from the field they can log into their account on the browser-based AusGeochem platform and view or edit all collected samples. After running subsequent geochemical analyses on the sample those results, including all metadata, can be stored in the database and attached to the sample. Once uploaded, data can be visualised within AusGeochem, using simple data analytics via technique-specific dashboards and graphs. The data can be shared with collaborators, downloaded in multiple formats and made public enabling FAIR data for the research community. 

Here we show a complete sample workflow example, from collection in the field to the final result as a thermochronology study. Sample analysis using fission track and (U-Th)/He and all associated data will be uploaded and stored in the AusGeochem platform. Once all analyses are complete, the data will be shared with collaborators and made available to the public. An important step during this process is by having an integrated IGSN minting option which will give the sample a unique global sample identifier, making the sample globally discoverable. 

Having all data stored in a clean and curated relational database with very detailed and fine-grained data models gives researchers free access to large amounts of structured and normalised data, helping them develop new technologies using machine learning and automated data integration in numerical models. Having all data in one place including all metadata such as ORCIDs from involved researchers, funding sources, grant numbers and laboratories enables the quantification and quality assessment of research projects over time.
Assessing ecosystem effects of changes to man​-made infrastructure in the ​North ​Sea
Authors: Bedington Michael , Lessin Gennadi , James Molly , Somerfield Paul
Published: March 2022

The north sea is a highly productive area, both biologically and for a variety of economic activities. It is also undergoing great change; anthropogenic usage is changing with Oil and gas activities ramping down whilst offshore wind installations are increasing, all against the increasing impact of climate change. For oil and gas structures there is an active debate as to the positive or negative ecosystem effects of different decom​missioning strategies for structures (e.g. removal, topp​ling). Whilst the effect of different options have been ​extensively studied at the level of individual structures, it is necessary to consider them in a basin wide context and ​in combination with the effect of other contemporary pressures.

Here we use coupled physics-biogeochemistry models (GOTM-ERSEM, FVCOM-ERSEM and FVCOM-PyLAG with specific adaptions for man-made structures to understand the possible scope and magnitude of effects on the north sea ecosystem for different decommissioning scenarios of oil and gas structures (removal, toppling, leaving intact). Specifically we look at the utilisation of structures by colonising organisms, the effects of trawling exclusion, and changes to connectivity. We also consider these with the addition of other man made structures (shipwrecks and wind farms) and under a future climate scenario.
Tropical Cyclones in Future HighResMIP Experiments : Explaining and Reconciling Projections
Authors: Vanniere Benoit , Roberts Malcolm , Hodges Kevin , Vidale Pier Luigi
Published: March 2022

Although most GCMs project a decline of tropical cyclone activity in a warmer world, some recent studies have cast doubts on this consensus by suggesting that the number of tropical cyclones might increase in future. The HighResMIP experiments offer such an example of contradicting projections. Indeed, AMIP-type experiments which have been forced by transient SSTs preserving the trend simulated by CMIP6 models in scenario SSP5-8.5, predict an increase of cyclone activity in the North Atlantic, whereas experiments with the same atmospheric models coupled to an ocean model predict a decline. In this paper, we intend to explain and reconcile those results. To do so, we compare several recent and past projects including HighResMIP, CMIP6 scenario SSP5-8.5 and the time-slice experiments of the UPSCALE project. We used several different approaches to explain the future change in TC activity, including SST anomalies relative to the tropical mean, the ventilation index for tropical cyclone genesis and predictors of tropical cyclone precursors.

SST anomalies show that subtle differences in SST trends between basins in the AMIP and coupled experiments can explain the differences in TC projections. This analysis should guide the construction of SST for the transient AMIP experiments used in future HighResMIP protocols. Once the less reliable projections have been discarded from our model ensemble, we show that there exists a remarkable agreement between the projections of HighResMIP coupled, scenario SSP585 and UPSCALE. We find that the saturation deficit is the component of the ventilation index which explains the largest fraction of the change, with the potential intensity and vertical wind shear playing a secondary role. Finally, we find that there is some agreement between models on the different time of emergence of a trend in TC activity in each basin, which we attempt to link to differences in the time of emergence of the trend of saturation deficit.
Characterising ice sheet properties using Rayleigh wave ellipticity
Authors: Jones Glenn , Ferreira Ana , Kulessa Bernd , Schimmel Martin , Berbellini Andrea , Morelli Andrea
Published: March 2022

The physical properties of the ice column are fundamental to the deformation and flow of glaciers and ice sheets. With a warming climate, surface meltwater is ever increasingly being routed and distributed throughout the ice column changing the mechanical and hence thermal properties of the ice and leading to accelerated ice flow and ice mass loss. Since the early 1990s, ice mass loss from the Greenland Ice Sheet (GrIS) has contributed ~10% of the mean global sea level rise. Seismic waves have routinely been used to study the physical characteristics of glaciers and ice sheets due to their sensitivity to both mechanical and thermal properties of ice. Traditionally, reflection seismic surveys have been chosen as the primary seismic approach but this survey method can suffer from difficult logistics in polar regions. Recent advancements in ambient noise methods and the permanent installation of a seismic network in Greenland now permit the long term study of the ice properties of the GrIS.

Rayleigh wave ellipticity measurements (the horizontal-to-vertical ratio of Rayleigh wave particle motions) are particularly sensitive to the subsurface structure beneath a seismic station. Using the polarisation properties of seismic noise, we extract Rayleigh wave ellipticity measurements from the Earth’s ambient noise for on-ice stations deployed in Greenland from 2012-- 2018. For wave periods sensitive to the ice sheet (T ≤ 3.5 s), we observe significant deviation between ellipticity measurements extracted from noise and synthetic fundamental mode calculations using a single ice column. Using a forward modelling approach we show: (1) a slow seismic shear-wave velocity at the near surface, (2) seismic attenuation, quantified as the quality factor Q, is sensitive to the temperature, water content and density of the ice and (3) the excitation of Rayleigh wave overtones plays a leading role in perturbing the ellipticity. Our results highlight how the inclusion of Q and overtone information can fill important gaps in our knowledge of ice sheet temperature, density and water content, which are important for predictions of the future evolution of the GrIS.
Inventory and characterization of recent (<100 years) gravitational activity of the Queyras DSGSDs - South French Alps
Authors: Boivin Clément , Malet Jean Philippe , Bertrand Catherine , Thiery Yannick
Published: March 2022

Deep Seated Gravitational Slope Deformation (DSGSD) are gravitational processes damaging slopes over long periods of time. These processes may be reactived with the occurrence of smaller, shallow gravitational events. Thus, a better understanding of DSGSDs, from their formation to more catastrophic phases of activity, is an important goal  for natural hazard prevention in mountainous areas. .A first inventory of DSGSD in the Western Alps has been proposed by Crosta et al. (2013) with 1057 DSGSDs identified. A similar work has been conducted more recently at the scale of the French Alps by Blondeau (2018) who identified nearly 460 DSGSDs. Despite the importance of these works, there are still many Alpine sub-massifs where high concentrations of DSGSDs (Blondeau., 2018) have been recognized but where no detailed studies have been conducted. This is the case of the Queyras Massif (South French Alps). It is in this context that this study is carried out, with both the objectives of locating and characterizing the DSGSDs observed in this area and identifying their recent activity.

The proposed approach is based on quantitative geomorphological studies combining photo-interpretation of multi-date aerial imagery, analysis of DSMs and field observations. Quantitative description criteria are proposed to identify DSGSDs and discriminate them from large deep-seated landslides. Thirty DSGSDs are inventoried and their lithological and structural setting is analyzed. Analysis of multi-date aerial photographs and InSAR derived landslide velocities (NSBAS processing of Sentinel-1 observations; e.g. André et al., XX?) allow characterizing their gravitational activity.
Evidence for a stronger global impact of fire on atmospheric composition
Authors: Randerson James , Chen Yang , Xu Li , Hall Joanne , Giglio Louis , van Wees Dave , Veraverbeke Sander , van der Werf Guido , Morton Douglas , Wiggins Elizabeth , Andela Niels , Hantson Stijn
Published: March 2022

Toward the development of the 5th generation of the Global Fire Emission Database (GFED5), we provide evidence for a significantly higher level of contemporary global fire emissions than what has been reported in previous inventories, as a result of advances in our understanding of burned area, fuel consumption, and emission factors. Increases in the availability of high-resolution burned area datasets from Sentinel and Landsat now allow for more effective estimation of fire scars associated with small and discontinuous fires in many biomes. By combining these regional-scale datasets with burned area and active fire observations from MODIS, we estimate that global burned area exceeded 700 Mha per year during 2001-2020. This estimate is more than 40% higher than previous estimates from GFED4 with small fires (GFED4s), mostly as a consequence of increases in savanna and grassland burning across Africa, South America, and Southeast Asia. At the same time, more extensive field observations in boreal forest ecosystems provide evidence for higher levels of fuel consumption than has been integrated into previous regional and global inventories. New emission factor observations from tropical peatlands and boreal forests provide evidence for a stronger smoldering phase of emissions, elevating emissions of carbon monoxide and organic carbon aerosol. Together, these advances suggest the impact of contemporary wildfires may have been underestimated in past work; we conclude by exploring the compatibility of this inventory with atmospheric aerosol and trace gas observations using a global atmospheric chemistry model.
Uncertainties of Surface Mass Balance in Greenland for the mid-Holocene as derived from CMIP6/PMIP4 simulations.
Authors: Neugebauer Rebekka , Rodehacke Christian B. , Lohmann Gerrit , Krebs-Kanzow Uta
Published: March 2022

The temporal evolution of Greenland’s surface mass balance (SMB) exerts an essential control on its volume, geometry, and sea-level contribution. Surface mass balance simulations based on future climate projections reveal considerable uncertainties. Here, we investigate Greenland’s SMB during past climate periods and assess the uncertainties due to model dependent climate forcing. Specifically we analyse the SMB of the pre-industrial climate and the mid-Holocene warm period.

 

We study the surface mass balance of the Greenland ice sheet with respect to uncertainties due to model dependent climate forcing. For this purpose, we create an ensemble based on the output of climate models of the sixth phase of the Coupled Model Intercomparison Project (CMIP6) and the fourth phase of the Paleomodel Intercomparison Project (PMIP4) (Brierley et al., 2020). This ensemble is used to simulate the SMB with the diurnal energy balance model (dEBM) (Krebs-Kanzow et al, 2021). As part of the analysis, we inspect anomalies and inter-model deviations of the mid-Holocene climate forcing, and evaluate the spread of spatial patterns of SMB anomalies in CMIP6/PMIP4. Our results indicate that the model-dependent climate forcing adds considerable uncertainty to SMB estimates over Greenland during the Holocene.

 

References

Brierley, C. M., Zhao, A., Harrison, S. P., Braconnot, P., Williams, C. J. R., Thornalley, D. J. R., Shi, X., Peterschmitt, J.-Y., Ohgaito, R., Kaufman, D. S., Kageyama, M., Hargreaves, J. C., Erb, M. P., Emile-Geay, J., D'Agostino, R., Chandan, D., Carré, M., Bartlein, P. J., Zheng, W., Zhang, Z., Zhang, Q., Yang, H., Volodin, E. M., Tomas, R. A., Routson, C., Peltier, W. R., Otto-Bliesner, B., Morozova, P. A., McKay, N. P., Lohmann, G., Legrande, A. N., Guo, C., Cao, J., Brady, E., Annan, J. D., and Abe-Ouchi, A., 2020: Large-scale features and evaluation of the PMIP4-CMIP6 midHolocene simulations, Clim. Past, 16, 1847–1872, doi:10.5194/cp-16-1847-2020, 2020. 

Krebs-Kanzow, U., Gierz, P., Rodehacke, C. B., Xu, S., Yang, H., and Lohmann, G., 2021: The diurnal Energy Balance Model (dEBM): a convenient surface mass balance solution for ice sheets in Earth system modeling, The Cryosphere, 15, 2295–2313, https://doi.org/10.5194/tc-15-2295-2021.
Sources and atmospheric aging processes of submicron aerosols in Cairo Megacity.
Authors: Christodoulou Aliki , Stavroulas Iasonas , Bourtsoukidis Efstratios , Pikridas Michael , Bezantakos Spyros , Hassan Salwa , El-Nazer Mostafa , Wheida Ali , Wahab Magdy , Boraiy Mohamed , Borbon Agnes , Afif Charbel , Sauvage Stéphane , Sciare Jean
Published: March 2022

Over the last few decades, Greater Cairo Megacity has experienced rapid population growth and expansion of its industrial activity. Hosting more than 20 million people, Cairo is considered one of the most polluted megacities in the world. Concentration levels of fine particulate matter (PM2.5) are several times higher than those recommended by the World Health Organization (WHO). Although actions have been designed recently to improve air quality in the framework of a “Pollution Management and Environmental Health program” (PMEH) supported by the World Bank, observational studies assessing the main sources leading to this PM pollution are missing, making difficult to implement and monitor the efficiency of local mitigation strategies.

The aim of our study is to investigate atmospheric concentrations levels, temporal variability, as well as major sources, and atmospheric aging of PM in Cairo megacity with a focus on the submicron aerosol fraction (PM1) to better assess human-made activities with lower interference from natural (dust) emissions. A comprehensive suite of on-line and off-line instruments has been set-up to monitor PM1 chemical composition and reactive trace gases (i.e. Volatile Organic Compounds) as a part of the POLCAIR campaign that took place during winter 2019-2020, at an urban background site in Greater Cairo. Chemical composition of PM1 and source apportionment analysis via Positive Matrix Factorization (PMF) on both Q-ACSM (Aerosol Chemical Speciation Monitor, Aerodyne, US) organic mass spectra and co-located filter samples, attributed exceptionally high concentrations of compounds to traffic emissions and diverse combustion sources with pronounced diurnal variability. Two severe pollution episodes were recorded, with hourly mean PM1 concentrations reaching values as high as 300 μg/m3 and lasting for 2 consecutive days favored by low dispersion conditions. Pollutant variability is directly associated with the meteorological conditions, including wind patterns and air mass origins. This helps in recognizing emission hot spots of major anthropogenic PM1 sources. Additionally, the effects of the relative humidity and the role of heterogeneous oxidation reaction mechanisms was investigated. Finally, the multi-variable analyses performed, helped us to better investigate the complex urban atmospheric chemistry in Cairo megacity and to highlight the dynamics of Secondary Organic Aerosol formation.
Protists and protist-microbe interactions in soil chips
Authors: Hammer Edith , Mafla Endara Paola Micaela , Klinghammer Nilsson Fredrik , Zou Hanbang , Duljas Julia , Ohlsson Pelle
Published: March 2022

Soil organisms live and interact in the intricate soil pore space labyrinth, but their natural habitat and natural interactions are difficult to study because of the opaqueness of the soil. We recently developed microfluidic model systems that simulate the spatial microstructure of soil microbial habitats in a transparent material, which we call Soil Chips. They allow us to study the impact of soil physical microstructures on microbes, microbial behavior and realistic microbial interactions, live and at the scale of their cells.

Using soil inocula, we get a large proportion of the natural microbial community into our chips and can study soil bacteria, fungi and smaller protists and nematodes in their food webs and in different spatial habitats. We were especially interested in soil protists that are generally understudied in their diversity and ecosystem functions. We were able to observe a large variety of flagellated, ciliated and amoeboid protists in the chips, predating on the bacterial populations and even on fungal hyphae. Some larger amoebae only entered the chips with their pseudopodia for predation. The colonization succession pattern of the chips showed predator-prey oscillations, with periodically high levels of different protists, followed by retreat or encystation. In chips that were containing initially dry pore spaces, colonization success of protists was strongly increased by the presence of fungal hyphae, which paved the way for protists by wetting pore spaces.

The soil chips enable us to study the influence of trophic interactions such as the presence of predators on bacterial and fungal nutrient cycling. Disturbances that stronger influence protists than bacteria may have a pronounced effect on bacterial population sizes and their organic matter degradation activities. Beyond the scientific potential, the chips can also bring soils closer to people and hopefully increase engagement in soil health conservation.
TD-PTR-MS for nanoplastics research – high sensitivity and big challenges
Authors: Materić Dušan , Notø Hanne Ødegaard , Mosselmans Sophie , Holzinger Rupert
Published: March 2022

Thermal Desorption – Proton Transfer Reaction – Mass Spectrometry (TD-PTR-MS) is a sensitive method capable of measuring nanoplastics in environmental samples. The method works on the principle that different types of plastic have different melting points (also different from many organics in the matrix), and they release rich (semi)volatile organic compounds signal (smells) when heated up. A gradual increase of the sample temperature combined with real-time, quantitative mass spectrometry (PTR-MS) allowed us to selectively measure the type and concentration of the nanoplastics. Data processing involves multiple ions associated with thermal degradation products of plastics, which ensures selectivity in identifying different plastic types.

However, the method is procedural and challenging. The sampling practice, sample treatment, instrument's operational settings, and data processing can result in large uncertainties, which need to be addressed in each experiment. Here we discuss these analytical challenges in the context of complex environmental nanoplastic measurement and provide recommendations for good experimental practice and robust quality control.
Imagine it's climate crisis - and nobody gives a sh**! Some reflections on climate change communication
Authors: von Elverfeldt Kirten
Published: March 2022

Imagine, a global climate crisis is happening – but nobody cares! With this presentation I want to take you on a journey into the heads of those people who will probably never be with us in academia, who will never enter university. To these people, climate change is not plausible – and they are right: Climate change is a systemic risk, and as such it is crossing borders, complex, stochastic, and there are tipping points, all of which leads to a general implausibility for those who are not quite into science. And I want to take you on a journey through 100 years of scientists failing to make people understand.
With this presentation I want to contribute to a better general understanding of what went wrong in our communication efforts and how we can improve. This reflection takes place on two levels:

The level of communication: (Geo-)science communication has to be very clear about the difference between the right and the almost right word. Furthermore, it has to be very clear about the difference between informing people and making people understand.

The level of the characteristics of climate change: The first level is even more important whenever we are dealing with systemic risks like climate change. In our communication efforts, we will have to pay more attention to the pitfalls and paradoxes of systemic risks than we have done so far. Probably the greatest paradox is that we are simply fearing the wrong: We are afraid of things that are highly unlikely (like getting robbed) whilst underestimating risks that are highly probable (like climate change) but not plausible on first sight.

Imagine, a global climate crisis is happening – and our communication is effective, thus the majority of people understands what is at stake. However, doing more of the same will not bring us to this stage. We might have to change the way we communicate and reach out.
Case study simulation of the green infrastructure influence on heat stress with urban climate model PALM-4U
Authors: Reinbold Alexander , Pavlik Dirk , Schubert-Frisius Martina , Teichmann Claas , Kriuger Antonina , Cortekar Jörg
Published: March 2022

City planners have to take multiple considerations and prospective issues into account when an urban area is to be developed. Especially in the cities, the heat island effect and the high population density combine to a health threat during heatwaves. Climate change exacerbates this heat stress and continues to do so for decades – a time scale relevant in urban planning. The increasing necessity to include urban climate adaption measures requires valid arguments for the decision-making process where they are in competition with other use of scarce urban space.

Urban climate models are a tool for assessments of the heat stress, wind comfort, the dispersion of pollutants and others – be it already built or only a proposed plan. The high-performance LES model PALM allows for modelling the atmospheric boundary layer from a whole-city level to a block of houses in resolutions up to 2 m. The model system PALM-4U can be adapted to the assessment question of interest by activating modules like urban surfaces. This incorporates, for example, urban green infrastructure from trees to façade greenery in the simulation. 

In this presentation, we show an application case for the model PALM-4U to assess a common planning question taken from municipal practice. The simulations investigate the impact of a high degree of green and blue infrastructure compared to a low degree in the plans of a development area. Climate adaption measures like façade greening, replacement of pavement with grass and ponds are evaluated in their cumulative effect on thermal comfort indices PT, PET and UTCI.

These simulations are part of the research project “ProPolis” that seeks to bridge the gap between science and practice in urban climate modelling by operationalizing PALM-4U into a practicable and user-friendly tool tailored towards the needs of municipalities and urban planners. ProPolis is part of the research and development program “Urban Climate Under Change [UC]²” funded by Germany’s Federal Ministry of Education and Research (BMBF).
Excitations of Alfven Wave by 3D Patchy and Intermittent Magnetic Reconnection
Authors: Yang Liping , He Jiansen , Feng Xueshang , Xiong Ming
Published: March 2022

Alfven waves make a central role in energy transfer of the solar atmosphere and heliosphere, with the potential to heat corona, accelerate solar wind, and drive Alfvenic turbulence. It has long been suggested that magnetic reconnection can generate Alfven waves through a relaxation of a highly curved reconnected field lines. Here, with a high-resolution simulation of 3D magnetic reconnection under the solar corona environment, we study this sketch and find that Alfven waves, whose features resemble to those of the Alfven Waves observed in the solar atmosphere, are continually and energetically excited by reconnection mainly through two ways. One involves the current sheet which experiences patchy and intermittent reconnections, and the other refers to the turbulence forming in the outflow regions. The Pointing flux carried by the excited upward-propagating Alfven waves can satisfy the requirements of plasma heating in the corona. This has implications for self-consistent considerations of energy budgets in the solar atmosphere and heliosphere.