bluuebunny/crossref_metadata_2025 huggingface dataset:
A physically-based ensemble of high-resolution regional climate simulations for Sub-Saharan Africa
Authors: Laux Patrick , Dieng Diarra , Portele Tanja , Arnault Joel , Lorenz Christof , Bliefernicht Jan , Kunstmann Harald
Published: March 2020

There is an increasing demand for sound climate information in Sub-Saharan Africa (SSA) for both regional and local scales. While climate information from Global Climate Models (GCMs) are usually too coarse for climate impact modelers or decision makers from various disciplines (e.g. hydrology and water management, agriculture, energy), Earth System Models (ESMs) provide feasible solutions for downscaling GCM output to required spatiotemporal scales. However, it is well known that the performance of regional simulations depends a lot on the physical parametrization, which may vary from region to region. Besides land-surface processes, the most crucial processes to be parameterized in ESMs include radiation, convection, and cloud microphysics, partly with complex interactions. Precipitation generation, for instance, involves many coupled processes between cumulus convection, cloud microphysics, radiation, land and ocean surface, and the planetary boundary layer. Before conducting long-term ESM simulations, it is therefore indispensable to identify a suitable physics parametrization combination. Based on the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis product ERA-Interim, we performed a set of 16 high-resolution physics parameterization experiments for SSA, using different cumulus-, microphysics-, planetary boundary layer-, and radiation schemes in the Weather Research and Forecasting (WRF) model for the period 2006-2010 in a spatial resolution of 9 km. Based on traditional (Taylor diagram, probability densities) and more innovative validation metrics (ensemble structure–amplitude–location (eSAL) analysis, Copula functions) and with the use of various observation data for precipitation and temperature, favorable parameterization combinations for whole SSA are identified and will be discussed also w.r.t. the required computing time. Here, we find that complex radiation schemes do not urgently lead to better simulation results for SSA, but increase the computing time tremendously.           
Amery Ice Shelf Grounding line detection using Cryosat-2 and Landsat8 data fusion
Authors: Zhang Yu , Zhu Tingting , Zhang Shengkai , Li Fei
Published: March 2020

We propose a grounding line detection algorithm for Amery Ice Shelf (AIS) using Cryosat-2 altimetry and Landsat8 optical data. The Grounding line represents the area where ice sheet separates from Antarctic ice cap and extends into the ocean, which is the key indicator of the inland ice sheet instability and the boundary conditions of numerical model for ice velocity calculation. Many studies focus on grounding line retrieval using altimetry data or remote sensing data either with lower spatial resolution or discontinuous, which makes it difficult for large scale and long-terms analysis. In this abstract, Bayesian MAP (Maximum a posteriori probability criterion) based Cryosat-2 altimetry and Landsat8 optical data fusion algorithm is proposed for grounding line extraction in AIS, Antarctic. For Cryosat-2 data, the along track based slope analysis is used to calculate the Gaussian curvature and mean curvature, where the area with largest slope variance is defined as the grounding points, which will act as the control points in the fusion framework. For the Landsat8 imagery with the spatial resolution of 30m, we first generate the 1km grid using cubic Hermite method. Based on the similarity measurement between texture feature and grounding line area, where the area with largest variance of mean value and standard deviation is defined as the grounding line in Landsat8 data.  For the MAP based fusion grounding line extraction step, the optimal procedure is to find the minimum distance between the Cryosat-2 grounding points and Landsat8 grounding line within a given area, so as to maintain the smoothness and discontinuous where the optical data is missing or the texture feature is not obvious. In the experiment part, the proposed result is compared with MODIS grounding line products, and the results indicate that the mean value is similar with Landsat8 result and standard deviation is lower. Moreover, since the Cryosat-2 data is not obstacle by cloud, it can provide continuous observation for AIS grounding line. Besides, the time series analysis shows that from 2016-2018, the grounding line did not change so much, which means that the AIS is stable with lower expansion rate.   
Exploring the role of vegetation and sediment supply to coastal dune states using integrated process-based modelling
Authors: Costas Susana , Kombiadou Katerina , Roelvink Dano
Published: March 2020

Coastal dune morphology is largely controlled by the availability of sand to be transferred from the beach and the capacity of the vegetation to trap and retain the moving sand grains. The resultant coastal dune morphology is, in turn, key to achieve maximum efficiency of nature-based solutions that plan the construction of such aeolian features. Therefore, developing approaches that integrate key processes becomes crucial, especially in order to efficiently design and test solutions that meet the timescale requirements of coastal management. The process-based XBeach-Duna model has been developed to integrate nearshore, aeolian and ecological processes across the beach-dune profile, thus allowing long-term simulation of complex coastal features and feedbacks. Here, we explore the potential of this coupled modelling solution to simulate the morphological response of coastal dunes to changes in sediment supply and vegetation cover over decadal timescales. Simulations show the capacity of the approach to reproduce the natural response to changes in sediment supply, shifting the shoreline position and simultaneously modifying the overall shape of the dune, within a range of dimensions that are in agreement with observations. In general, narrow and low dunes are formed under high supply conditions, wide and high dunes develop if sediment supply is low and the shoreline position stable, while narrower and higher dunes are created after a relative drop in sediment supply that induces a negative budget. Denser vegetation coverage, on the other hand, favours taller dune morphologies, however the influence of sediment supply and receding shoreline positions to plant growth are non-linear and, in turn, produce feedbacks that cascade to the morphology of the dune itself. These results demonstrate the capacity of the approach to reproduce different dune states, resulting from alternative evolutionary pathways, and its potential to identify coastal dune (in)stability domains and critical morphological shifts, factors that are key to better understand the efficiency of dunes as nature-based solutions for coastal management.

This work was supported by the project PTDC/CTA-GFI/28949/2017, funded by the Portuguese Foundation for Science and Technology.
'Islands of excellence’ in catastrophe & disaster risk data, tools and services in the face of the climate change crisis – how can innovation systems advance stakeholder understanding and use of catastrophe and disaster sciences?
Authors: Irvine Tracy
Published: March 2020

New catastrophe and disaster risk data, tools and services can often include complex science and algorithms that offer profoundly important information on understanding risk or can inform climate adaption. However, if few people know about or understand how and in what context to use these tools, they remain on the databases of academic institutions and in scientific journals across the world. How many tools that could transform the world’s understanding of risk and ways to adapt to that risk already exist or are currently under development? The answer is likely to be in the hundreds. But, how many of those tools have ever been used beyond one or two scientific case studies? The answer is likely to be, in most cases, very few.

 

Academic institutions often administer barriers on access to their data and tools through institutional data management and by specifically implementing non-commercial use licensing in the dissemination of tools once scientific studies are completed. In addition, very commonly, insufficient thought is put to the exploitation strategies of these tools. The gaps in understanding and trust between academia and the needs of business sometimes feel insurmountable on both sides. Is ‘custom’ defying reason in the face of the climate change crisis and the need for rapid systems transformation globally?

 

The Oasis family, offers new approaches around transparency, collaboration, dissemination and exploitation and the encouragement of intereoperability by providing platforms that allow for comparative approaches to scientific data and tools.

 

Firstly, "OASIS LMF is an open source platform for developing, deploying and executing catastrophe models to enable the “plug and play” of hazard and vulnerability modules (along with exposure and insurance policy terms) by way of a set of data standards that describe a model. It has been built in collaboration with the insurance industry (https://oasislmf.org/)." Oasis Palmtree offers support to enable access to this system.

 

Secondly, Oasis Hub, has designed science innovation approaches to bringing tools and data to wider, diverse audiences in collaboration with scientific institutions. We discuss "OASIS Hub, as a global window and conduit to free and commercial environmental, catastrophe and risk data, tools and services (https://oasishub.co/) as an example of a new innovation approach.
Earthquake density along the Western Alpine Arc
Authors: Sue Christian , Mathey Margot , Hannouz Estelle , Walpersdorf Andrea , Baize Stephane
Published: March 2020

We propose a new analysis of the W-Alpine seismicity based on space and time distributions along the Alpine arc. The overall area bears witness of a relatively important seismic activity localized along the so-call Briançonnais and Piemontais seismic arcs, but also along alignments corresponding to individualized active fault, e.g. in front of the Belledonne massif, and locally in form of important seismic swarms (Ubaye, Maurienne, Mont-Blanc). The regional tectonic regime is well analyzed (see for instance Mathey et al., this session), with detailed mapping of both the stress and strain fields. However, actual available studies do not take into account the time and space distributions. Our study is developed using several available datasets covering various time spans and various strategies (local and regional seismic networks, template matching, historical seismic catalogue). We focus firstly on the space distribution of the activity along the arc, taking into account: (i) the simple occurrence of seismic events to calculate regional density maps, also investigating the B-value mapping; and (ii) the energy density, using the seismic moment fluxes per surface unit as a proxy. On this basis, we secondly analyze the time evolution of the seismicity, which is actually limited by the available dataset’s time span. Our integrated analyze focusses on 3 primary targets: (i) to compare the information arising from the different databases; (ii) to compare the most active zones in terms of earthquake occurrence vs. seismic energy released; (iii) to unravel potential evolutions or establish relative steadiness in alpine seismicity through time. This work will finally allow to better understand and discuss the Alpine seismicity’s mechanisms, in relation with the actual dynamics of this orogen.
Grid-based global coastal zone datasets for coastal impact analysis
Authors: Lincke Daniel
Published: March 2020

Global coastal impact and adaptation analysis in the context of climate change induced sea-level rise needs precise and standardized datasets. Here, such datasets and their construction are presented. Starting from a high-resolution global digital elevation model, the coastline is extracted with taking into account river mouths and lagoons taken from a global surface water dataset. The global low-elevation coastal zone (LECZ) is derived by determining all grid cells hydrological connected to the coastline. Recent surge-data is combined with sea-level rise scenarios to partition the global LECZ into local floodplains. Latest socio-economic and land-use data is used to partition and classify these local floodplains. As local impacts and adaptation responses are not spatially uniform, but depend on a range of conditions including: i) biophysical conditions such as natural boundaries between floodplains (e.g. hills, rocks, etc.) and coastal geomorphology (e.g. sandy versus rocky shores), ii) technical conditions such as existing flood protection infrastructure (e.g. dike rings in the Netherlands), and ii) socio-economic conditions such as administrative boundaries, land use and urban extent (e.g. rural versus urban areas), latest land-use, beach and wetland datasets are used to partition the coastline of each floodplain into a network of coastline segments which can be used for assessing local shoreline management options.

The generated datasets contain about 1.6 million km of coastline distributed over 87,600 islands. The LECZ comprises 3.14 million km² and partitioning this LECZ with surge and sea-level rise data into floodplains for coastal impact modelling finds about 221,800 floodplains with at least 0.05 km² area.
A pan-African high-resolution drought index dataset
Authors: Peng Jian , Dadson Simon , Hirpa Feyera , Dyer Ellen , Lees Thomas , Miralles Diego G. , Vicente-Serrano Sergio M. , Funk Chris
Published: March 2020

Droughts in Africa cause severe impacts such as crop failure, food shortages, famine, epidemics and even mass migration. To minimize the effects of drought on water and food security over Africa, a high-resolution drought dataset is essential to establish robust drought hazard probabilities and to assess drought vulnerability considering a multi- and cross-sectorial perspective that includes crops, hydrological systems, rangeland, and environmental systems. Such assessments are essential for policy makers, their advisors, and other stakeholders to respond to the pressing humanitarian issues caused by these environmental hazards.  In this study, a high spatial resolution Standardized Precipitation-Evapotranspiration Index (SPEI) drought dataset is presented to support these assessments. We compute historical SPEI data based on Climate Hazards group InfraRed Precipitation with Station data (CHIRPS) precipitation estimates and Global Land Evaporation Amsterdam Model (GLEAM) potential evaporation estimates. The high resolution SPEI dataset (SPEI-HR) presented here spans from 1981 to 2016 (36 years) with 5 km spatial resolution over the continent of Africa. To facilitate the diagnosis of droughts of different duration, accumulation periods from 1 to 48 months are provided. The quality of the resulting dataset was compared with coarse-resolution SPEI based on Climatic Research Unit (CRU) Time-Series (TS) datasets, and Normalized Difference Vegetation Index (NDVI) calculated from the Global Inventory Monitoring and Modeling System (GIMMS) project, as well as with root zone soil moisture modelled by GLEAM. Agreement between the coarse resolution SPEI from CRU TS (SPEI-CRU) and the developed SPEI-HR provides confidence in the estimation of temporal and spatial variability of droughts in Africa with SPEI-HR. In addition, agreement of SPEI-HR versus NDVI and root zone soil moisture – with average correlation coefficient (R) of 0.54 and 0.77, respectively – further suggests that SPEI-HR can provide valuable information to study drought-related ecological and societal impacts at sub-basin and district scales in Africa. The dataset is archived in Centre for Environmental Data Analysis (CEDA), with link: http://dx.doi.org/10.5285/bbdfd09a04304158b366777eba0d2aeb (Peng et al., 2019). 

 

Peng, J.; Dadson, S.; Hirpa, F.; Dyer, E.; Lees, T.; Miralles, D.G.; Vicente-Serrano, S.M.V.-S.; Funk, C. (2019): High resolution Standardized Precipitation Evapotranspiration Index (SPEI) dataset for Africa. Centre for Environmental Data Analysis, 05 August 2019. doi:10.5285/bbdfd09a04304158b366777eba0d2aeb.
Impact of Solar Wind High Speed Streams on Ionospheric Current Systems
Authors: Pedersen Marcus , Vanhamäki Heikki , Aikio Anita , Käki Sebastian , Viljanen Ari , Workayehu Abiyot , Waters Colin , Gjerloev Jesper
Published: March 2020

High speed streams (HSS) and associated co-rotating interaction regions (CIR) in the solar wind are one of the major drivers of geomagnetic activity, especially during declining phases of sunspot cycles and near sunspot minima. We have identified 51 HSS/CIR driven geomagnetic storms that coincide with a Dst drop to less than -50nT during the period 2009-2018 and we investigate their impact on ionospheric current systems. Our approach is to study the evolution of the global scale current systems, i.e. the auroral electrojets and Region-1/2 field-aligned currents (FAC), with the SuperMAG magnetometers and AMPERE satellite data, respectively. The events are studied with a superposed epoch analysis centered at the storm onset to see the general behavior of the current system globally and in four different MLT sectors: noon, dusk, midnight and dawn. A minor enhancement of the integrated FAC was observed in the midnight, dawn and dusk sector 3 hours before the storm onset. The largest FAC and variability was observed in the dusk sector, and the integrated FAC maximum occurred in the middle of the storm main phase, 4 hours before the Dst minimum. This result will be compared to the evolution and behavior of the electrojet currents from superMAG. In the future a similar study will be conducted for ICME geomagnetic storms and compared to the HSS/CIR-related storms.
A bivariate hydrological methodology for improving flood maps
Authors: Caporali Enrica , Isola Matteo , Garrote Luis
Published: March 2020

Flood risk is the combination of the probability of a flood event and the potential adverse consequences for the human health, the environment, the cultural heritage and the economic activity associated with a flood event (2007/60/EC). Usually, the potential consequence of a flood with a certain probability is evaluated through the flood stage raised in the analysed area, combined with the variables characterising the type of vulnerability. Indeed, flood damages are evaluated from stage-damage curves, also called damage functions. Recently, flood social vulnerability indexes are defined taking into account the flood stage as the primary hydraulic variable. The standard approach evaluates the flood stage starting by a univariate hydrological load, corresponding to one hydrograph with a peak discharge of a certain probability and adequate durations. This correspondence is a critical issue that is originated from the approximation of the river flood flow process. A bivariate hydrological methodology for improving flood maps is proposed. A consistent number of synthetic hydrographs composes the bivariate hydrological load, with peak discharge and volume belonging to their bivariate distribution. A flood map corresponds to each hydrograph. Each flood map is a grid developing through 2d hydraulic model. A specific flood stage value corresponds to each cell of the grid. The whole set of hydrograph produces a flood stage series for each grid cell. The flood map with a certain probability, i.e. return period, results from the interpolation of the corresponding quantile values for each grid cell. The methodology is applied to a case study. The resulting map is benchmarked with a map obtained by the standard hydrological approach. The proposed methodology is based on tools that are widely known and it is replicable by the public administrations or public entities that are interesting in the hydrologic and hydraulic risk assessment.
A new method for characterising the Antarctic Circumpolar Currents using Argo float temperature and salinity profiles
Authors: Roberts Luke , Jones Rhiannon , Donnelly Matthew , Hendry Katharine
Published: March 2020

Argo is an array of automated profiling floats, which have allowed the rapid development of high-resolution and high-quality oceanographic data acquisition. The international program has been in operation since the 1990s providing continuous hydrographic data globally. There are now over a million individual float profiles, contributing to our understanding of global ocean physical properties, such as circulation processes at both a local and regional scale. With these innovations come the challenges of data processing, and compilation of user-friendly data products. For example, the Southern Ocean is a critical region that modulates our climate, via heat exchange, carbon storage, biogeochemistry, and primary productivity. An improved quantified understanding of Southern Ocean currents, informed by Argo, must be implemented in policy-relevant high-resolution climate models to advance our understanding of future change.

 

In May 2019, a new collaboration was formed between the Southern Ocean Argo Resource Centre (British Oceanographic Data Centre) and the University of Bristol. The aims were two-fold: to produce a method for characterising Southern Ocean frontal zones using Argo floats, and to train early career researchers in the University sector in data processing and management. We have created a publicly available code that characterises physical features of the Antarctic Circumpolar Current using Argo float profiles, using minimal software, and without the need to access high-performance computers. The code categorises each profile based on the temperature and salinity ‘fingerprints’ of zones between each Southern Ocean front. This allows the user to produce output surface plots from user-specified time-slices and geographic areas, and so compare frontal movement in time and space.
On the invariants of velocity and magnetic field gradient tensors in MHD theory
Authors: Consolini Giuseppe , Quattrociocchi Virgilio , Materassi Massimo , Alberti Tommaso , Stumpo Mirko
Published: March 2020

In the framework of MHD turbulence, the velocity and magnetic field topological features can be characterized by three quantities invariant under rotations, which are defined by the velocity and magnetic field gradient tensors. These quantities provide information about field structures and dissipative features. 
In this work we present a preliminary derivation of the evolution of the invariant quantities of the velocity and magnetic field gradient tensors in the framework of MHD theory, using a Lagrangian point of view. This work can be considered as a first step useful to characterize and describe the evolution of the fields structures in  heliospheric space plasmas. Furthermore, some examples of the statistical features of magnetic field gradient tensor invariants, in the inertial and dissipation ranges, are also shown and discussed. 
Simulating the propagation of wet snow avalanches: challenges and perspectives
Authors: Chambon Guillaume , Faug Thierry , Naaim Mohamed , Eckert Nicolas
Published: March 2020

Recent winters saw a striking increase in wet snow avalanche activity. Compared to dry avalanches, wet snow avalanches present uniquely distinctive features such as slower velocities, larger depths, unusual trajectories and deposit shapes, and a paste-like rheology that can result in large shear and normal stresses. In addition, the behavior of wet avalanches may strongly vary depending on the actual snow liquid water content. Complex transitions between dry (cold) and wet (hot) behaviors have also been observed during the propagation of single avalanche events. Current numerical models of avalanche dynamics are challenged when it comes to capturing the full spectrum of these different regimes, and the transitions in between. In this contribution, we critically review the various rheological models that have been proposed in the literature to simulate dry and wet snow avalanches in the frame of depth-averaged shallow-flow approaches. On this basis, a simplified parametric rheological law is proposed, with the objective of representing both dry-like and wet-like behaviors and allowing for smooth transitions between them. The law is implemented in a robust 2D shallow-flow simulation code, and systematic sensitivity studies are performed on synthetic and real topographies. Simulation outcomes are analysed in terms of propagation dynamics and deposition patterns, and the ability of the model to capture both dry and wet regimes is discussed. Lastly, a specific calibration methodology is proposed to infer the relevant mechanical parameters from documented avalanche events.
Post-seismic deformation of the 2010 M w 7.4 Ogasawara Islands outer-rise earthquake evidenced by Repeating Earthquakes.
Authors: Gardonio Blandine , Kato Aitaro , Michel Sylvain , Schubnel Alexandre
Published: March 2020

 

Although far from the Japanese main island of Honshu, the Izu-Bonin area is a very active seismic zone. It experienced two major earthquakes in the past decade: (i) the 2010 Mw 7.4 Ogasawara Islands intraplate earthquake that occurred on the 2010/12/22 in a normal-fault, in the outer-rise of the trench of the Pacific plate that subduct underneath the Philippine Sea plate, (ii) the Mw 7.9 Bonin island very-deep focus earthquake that occurred on the 2015/05/30 that was preceded by an acceleration of the seismicity at large depth. The aftershocks of the outer-rise earthquake were distributed in a NW-SE belt and formed subparallel lines along a fracture zone in the Pacific plate. The aftershocks were first located in the surroundings of the main shock rupture and migrated over the following days beyond or into the Ogasawara Plateau and the Uyeda Ridge. Due to its location in the sea and with only a few GPS and seismic stations around, it is difficult to assess the extent of the post-seismic deformation of this earthquake.

In that context, the analysis of repeating earthquakes as a proxy for slip on the fault is very useful. Using ten seismic stations, we detected 130 repeating earthquakes. Their number inscreased in the next few days following the main shock and are located in the northern branch of the fault. Ten days later, another increase of repeating earthquakes occurs on the subduction interface concomitent with a displacement to the east seen by GPS stations, indicating that the outer-rise earthquake might have triggered a slow slip event on the subduction interface. The main shock was also followed by an extremely rapid migration of the seismicity at depths up to 80km showing that it perturbed the entire outer-rise structure of the slab at depth.
Extension and transtension associated with strike-slip faults and its relation with aquifer potentials: a case study in Aravalli terrane (North Gujarat), India
Authors: Pradhan Rudra Mohan , Biswal Tapas Kumar
Published: March 2020

Fractured rock aquifers are one of the most difficult aquifers to characterize due to complex geometry and fracture network. In Aravalli terranes of North Gujarat, communities depend on basement rock aquifers as the primary source of water supply. The hydrogeology of these aquifers is poorly understood and the drinking/irrigation wells are frequently placed in this area with little appreciation of the fracture systems. Increasing water demand puts stress to explore groundwater from less reliable sources of basement rocks and hence, makes it vital to identify potential hydrogeological zones. Lineament studies are commonly used for targeting groundwater bearing zones in hard rock terrane and very often ignore the other important structural settings viz. extension, transtension etc. For the present study, structural data pertaining faults and fractures have been mapped through fieldwork and Electrical resistivity imaging (ERT) technique. The key objective of the study is to correlate the structural features (extensional and transtensional settings) with geophysical profiles and to find out potential hydrogeological zones from where water can be explored economically. The study area comes under the Ambaji basin of Aravalli-Delhi fold belt which is a Proterozoic fold belt running 700-800 km in NE-SW direction and situated in NW India. The Aravalli-Delhi fold belt had undergone multiple phases of deformation. In this area, three major sets of fractures are present and are oriented largely in WNW-ESE, NE-SW, and NW-SE direction. The WNW-ESE fracture is dextral in nature which has interpreted from the displacement of fold limbs. Further, these are right lateral en-echelon normal faults where NE-SW extension has been taken place. There is another set of fracture i.e. NW-SE which is due to stretching of strike-slip fault. The ductile shear zones in the area are also parallel to the NW-SE fracture set. The shear zones are opened-up due to extension and formed potential aquifers. ERT has been carried out along and across the fractures to understand the subsurface fracture geometry. The ERT shows deep sited fractures and low resistivity values at the cross-section of WNW-ESE faults with the shear zone. This concludes a strong correlation between different structural settings with potential aquifers which could be used for pumping as well as artificial recharge sites for long term sustainability.

Keywords- Aravalli terrane, Aquifer, Extension, Fracture, ERT
Low energetic Interstellar hydrogen atoms in the heliosphere: Decade of IBEX observations
Authors: Katushkina Olga , Izmodenov Vladislav , Galli André
Published: March 2020

This work is devoted to the analysis of the interstellar hydrogen fluxes measured by IBEX spacecraft from 2009 to 2018. To calculate the fluxes we use our 3D time-dependent kinetic model of the hydrogen distribution in the heliosphere that takes into account non-maxwellian behavior of the velocity distribution function of hydrogen atoms due to charge exchange with protons at the heliospheric boundary. The temporal variations of the hydrogen fluxes during the entire solar cycle are considered and analyzed by comparison of the IBEX-Lo data and the model results. During solar maximum the measured fluxes are too low, therefore we choose several years 2009-2011 and 2017-2018 when the signal-to-noise ratio is appropriate. A parametric search is performed to determine the influence of different model parameters on the full sky maps of the fluxes. It is found that solar radiation pressure is the most crucial parameter for the position of the maximum fluxes, while the heliolatitudinal variations of the charge exchange ionization rate influence the shape of the maps during solar minimum conditions. The quantitative differences between the data and the model results are demonstrated, and several possible reasons for them are discussed.
The kids aren’t alright
Authors: Thiery Wim , Lange Stefan , Rogelj Joeri , Seneviratne Sonia I. , Schleussner Carl-Friedrich , Frieler Katja , Bauer Nico ,   ISIMIP modelling team
Published: March 2020

Will a new-born experience more impacts from climate change compared to a 60-year old? While the obvious answer to this question is yes, impacts accumulated across an average person’s lifetime have so far not been quantified. Providing such information is however relevant and timely, given the recent surge in societal debate regarding inter-generational solidarity and considering ongoing climate litigation. Here we combine multi-model impact projections from the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) with temperature trajectories from the IPCC special report on warming of 1.5°C and life expectancy data from the World Bank to compute accumulated impact exposure across lifetimes of people in different age groups and countries. We consider six impacts categories (droughts, heatwaves, tropical cyclones, crop failure, floods, and wildfires), for which ISIMIP provides a total of 170 impact projections with 15 different impact models under RCP2.6 and 6.0. Our results highlight that the combined increase in life expectancy and unfolding climate impacts leads to 2-4 times more impacts affecting a new-born compared to a 60-year old person under current policy pledges. Globally, the increase in exposure for young people is dominated by the strong increase in heatwave hazards. The strongest increases occur in low and lower-middle income countries, where rising impacts compound a substantial increase in life expectancy. Our results overall highlight the strong benefit of aligning policies with the Paris Agreement for safeguarding the future of current young generations.
How unusual are fire conditions ?
Authors: Di Giuseppe Francesca , Vitolo Claudia , Krzeminski Blazej
Published: March 2020

Extreme fire danger is expected in certain regions at summer times. However in some cases (e.g. Australian fire in 2019) possibly because of  early onsets or  prolonged conditions,  fires lead to catastrophic outcomes. These events are often referred as "anomalous" without a quantification. At the European Centre for Medium-Range Weather Forecasts (ECMWF), one tool that could aid pinpointing how uncommon these  situations  are  is the extreme forecast index (EFI), an index that highlights regions that are forecast to substantial diverege  from  to the local climate. 
The EFI concept has been in the past applied to meteorological fields such as temperature and precipitation. In this work we build on  previous findings by undertaking a global verification out to 15 days forecast  on the ability of the EFI for the Fire Weather Index (FWI)to capture extreme observed fire. Using the ECMWF ensemble prediction system and probabilistic skills score we analyse the fire season in  2019. In most case the  EFI is more skillful than the simple FWI to detect anomalous conditions for fire danger.

Following these results, the operational implementation of the FWI EFI  is currently being planned.
Inter-hemispheric comparison of the ionosphere-plasmasphere system from multi-instrumental/model approach.
Authors: Bergeot Nicolas , Habarulema John Bosco , Chevalier Jean-Marie , Matamba Tshimangadzo , Pinat Elisa , Cilliers Pierre , Burešová Dalia
Published: March 2020

An increasing demand for a better modelling and understanding of the Ionosphere-Plasmasphere system (I/Ps) is required for both scientific and public practical applications using electromagnetic wave signals reflecting on or passing through this layer. This is the case for the Global Navigation Satellite Systems (GNSS, i.e. GPS, GLONASS, Galileo) and for spacecraft designers and operators who need to have a precise knowledge of the electron density distribution.

Additionally, despite the long-term ionospheric studies that have been on-going for many decades, a number of aspects are still complicated to understand and forecast accurately even in mid-latitude regions during quiet conditions. Performing inter-hemispherical climatological studies in European and South African regions should highlight differences/similarities in I/Ps response during different phases of solar activity and geophysical conditions.

In that frame, the Royal Observatory of Belgium (ROB) and the South African National Space Agency (SANSA) started a collaboration named “Interhemispheric Comparison of the Ionosphere-Plasmasphere System” (BEZA-COM). The goal is to provide inter-hemispheric comparison of the I/Ps implying: (1) a characterization of the climatological behavior of the Total Electron Content (TEC) in the I/Ps, over European, South African, Arctic and Antarctica regions; (2) an identification of the mechanisms that regulate inter-hemispheric differences, asymmetries and commonalities in the I/Ps from low to high-latitudes, (3) study of the different responses of the I/Ps during extreme solar events and induced geomagnetic storms in the two hemispheres.

In this paper, we reprocessed the GNSS data (GPS+GLONASS) of the dense EUREF Permanent GNSS Network (EPN) and South African TRIGNET networks as well as IGS stations for the period 1998-2018. The output consists in vertical Total Electron Content (vTEC), estimated every 15 min., and covering the central European and South African regions. The vTEC is then extracted at two conjugated locations and used to constrain empirical models to highlight the climatological behavior of the ionospheric vTEC over Europe and South Africa. From the results, we will show that the differences are quite significant. To give first answers on these differences, we also compared these models with ionosondes long-term data based models (for foF2 and hmF2) at two conjugated locations (Grahamstown and Průhonice) as well as long-term NRLMSISE O/N2 ratio.
Dome C North radar, a new radar of the SuperDARN network: the first year of observations.
Authors: Marcucci Maria Federica , Coco Igino , Massetti Stefano , Longo Simona , Biondi David , Simeoli Enrico , Cirioni Alessandro , Satta Andrea , De Simone Angelo , Marchaudon Aurélie
Published: March 2020

In January 2019 the new Super Dual Auroral Radar Network (SuperDARN) radar installed at the Concordia Station in Antarctica and denominated Dome C North (DCN) saw the first light. SuperDARN is an international network of HF radars that observe the effects produced in the ionosphere by the chain of phenomena taking place in the Earth's space environment. DCN and its companion radar Dome C East (DCE) are positioned nearby the southern geomagnetic pole with their Field of View extending towards the auroral latitudes. Here we present the analysis of the first year of observations as a function of the interplanetary conditions.
When appearances lie: micropedology of palaeosol markers in a Pleistocene sedimentary record from central Po Plain
Authors: Mariani Guido Stefano , Muttoni Giovanni , Norini Gianluca , Aghib Fulvia S. , De Franco Roberto , Piccin Andrea , Zerboni Andrea
Published: March 2020

Environmental and time-scale reconstructions of deep sedimentary sequences are based on a wide variety of markers to highlight and characterise environmental variations within a homogeneous sedimentary setting. Moreover, in the lack of reliable age constrain, it is often the only way to highlight timelines and correlations between sequences collected in different places. Within this set of potential markers, palaeosols developed on terrestrial sedimentary beds during biostasy conditions stand out. These evidences are often useful for both their visibility within a core and their strong environmental implications. In continental basins characterized by glacial contributions, they also represent potential time information linked to the fluctuation of glacial and interglacial periods. However, the interpretation of sedimentary markers in cores using visual identification to the naked eye can possibly lead to the wrong conclusions: this method for palaeosol identification is not straightforward and prone to the production of false positives. We conducted detailed micromorphological investigations on a series of markers in a core from the central-northern portion of the Po Plain foreland basin, proximal to the Southern Italian Alps which fed the basin during the Pleistocene.

Seventeen sedimentary anomalies were identified during the visual description on the basis of colours and textures as potential palaeosols and were sampled to be studied in thin section. The study allowed to recognise evidences of soil-forming processes, which could characterise the past pedogenesis as well as their environment. From micromorphological analysis, only 4 samples showed visible signs of pedogenesis or post depositional weathering caused by proximity to the surface. Observed elements range from pedoplasmation to pedogenetic features related to redoximorphic processes and clay illuviation, thus allowing to interpreted them as truncated palaeosols. Conversely, 6 samples showed forms of transport of soil material, either sedimentary or in solution, but did not represent soils formed in situ; these can be interpreted as pedorelicts. Of the remaining samples, 5 were calcrete potentially related to groundwaters, and 2 represented accumulations of Fe/Mn oxides in wetland conditions (“bog iron”). These results suggest a reconsideration of the role of palaeosols as stratigraphic markers in the study of subsurface sedimentary sequences. Precise identification and microstructure characterization are necessary to avoid possible misinterpretations and correlations among cores.
The model of outer radiation belt electron lifetimes based on combined Van Allen Probes and Cluster VLF wave measurements
Authors: Aryan Homayon , Agapitov Oleksiy , Artemyev Anton , Balikhin Michael , Mourenas Didier , Boynton Richard
Published: March 2020

The flux of highly energetic electrons in the outer radiation belt show a high variability during geomagnetically disturbed conditions. Wave-particle interaction with VLF chorus waves play a significant role in the flux variation of these particles, and quantification of the effects from these interactions is crucially important for accurately modeling the global dynamics of the outer radiation belt and for providing a comprehensive description of electron flux variations over a wide energy range (from the source population of keV electrons to the relativistic core population of the outer radiation belt).  In this study, we use the synthetic model based on the combined database from the Van Allen Probes and Cluster spacecraft VLF measurements (including the recent findings of wave amplitude dependence on geomagnetic latitude, wave normal angle distribution, and variations of wave frequency with latitude) to develop a comprehensive parametric model of electron lifetime in the outer radiation belt as a function of geomagnetic activity, L-shell, and magnetic local time. Results show high local scattering rates during moderate and active conditions, local scattering is higher on the dawn and night side compared to day side, and electron lifetime is short during active conditions. 
Basin modelling as a predictive tool for potential zones of chimney presence
Authors: Peshkov Georgy , Ibragimov Iskander , Yarushina Victoria , Myasnikov Artem
Published: March 2020

Today, the problem of global climate change is the most exciting challenge for the world community of scientists. One of the most recommended technology for decreasing carbon dioxide concentration in the atmosphere is its injection into natural geological reservoirs. The most significant attention is paid to this issue in Norway offshore. Such operations must be conducted with extreme caution since, in the petroleum systems of north European seas, such a phenomenon as a gas chimney is widespread. The most straightforward indicator for detecting them is pockmarking at the bottom of the sea. Nevertheless, it does not provide information about the depth of the gas formation zone. Thus, we cannot identify the genesis of the chimney, the instability of the gas hydrate zone or reservoir gas leakage. Identification of the chimney root also can be determined using seismic monitoring, but this is an expensive study.

In this work, we suggest the new method to identify the potential zones of reservoir chimney based on basin modelling data interpretation. We compare the anomalies of physical fields calculated in the simulator with detected acoustic noises on the seismic profile associated with the chimney being at a depth of ~ 2 km to the surface of the seabed. The pattern of the presence of the chimneys is determined. The study is conducted on a 2D basin model along with the PETROBAR-07 profile of the south-west part of the Barents Sea.
Quantifying the contribution of land use change to the surface urban heat island in China
Authors: Qiao Zhi , Liu Luo , Han Dongrui , Sun Zongyao , Xu Xinliang
Published: March 2020

Urban Heat Island (UHI), a phenomenon characterized by significantly higher air and land surface temperatures (LSTs) in urban areas than in suburban areas, results in land use change from non-urban to urban land and is accompanied by increases in anthropogenic heat release. A variety of land use contribution indexes have been proposed to quantitatively calculate the impact of land use types on UHI. However, these indexes can only show the impact of specific land use types on UHI. In fact, the area and the intensity (which also can be considered as the average temperature) of land use change jointly determine the regional UHI. The purpose of this paper is to develop an algorithm to quantitatively reveal the influence of the area and the intensity of land use change on regional UHI. MODIS LST products and 1:1,000,000 land use data sets were used to quantitatively calculate the seasonal and interannual contributions of land use change on regional UHI between 2005 and 2018 in China. These results have theoretical and practical significance for further understanding the formation mechanism of urban thermal environment and its mitigation measures.
Latitudinal Variation and Nonlinear Behavior of Internal Tides in the East China Sea
Authors: Wang Weidong , Robertson Robin
Published: March 2020

We present four sets of concurrent ADCP data obtained from the East China Sea shelf, and it suggests that near-inertial waves induced by parametric subharmonic instability (PSI) associated with harmonic transfer beyond diurnal critical latitude (O1:27.6°, K1:30°). Two type different nonlinear behavior (harmonic transfer and subharmonic transfer) occur varying with the latitude on different location. The velocity data indicated a transfer of diurnal internal tidal energy poleward of the diurnal critical latitude. Kinetic energy and shear spectra analysis at these moorings reveals that the prominent peaks enhance and appear at not only at the even order of diurnal tide such as semidiurnal band, 4cpd, 6cpd and even 8cpd, but also some unfamiliar odd harmonics 3cpd and 5cpd. Furthermore, additional energy is converted to higher mode locally through continuum internal wave spectrum. Besides the harmonic transfer, on the critical latitude for D2/2 wave(28.9°), D1 wave is extracted from a D2 tidal driven model output current. PSI conversion of semidiurnal internal tidal energy was confirmed by spectra analysis and bi-spectra, because of the distinguish of M2/2 separated from the diurnal tidal (O1, K1).
Highlights on a UNESCO/Sida project to assess the environmental and health challenges of mining activities in Sub-Saharan Africa
Authors: S. Félix Toteu
Published: March 2020

Mining is an important pillar of economic growth of many African countries. However, problems arising from this activity pose serious challenges, which most of these countries have difficulties to address properly because of poor environmental governance as highlighted in the Africa Mining Vision. Many African countries also lack a precise inventory and assessment of environmental impacts of abandoned and derelict mines. As a consequence, there is an urgent need to evaluate the true extent of the detrimental effects of metal and metalloid pollutants and their impact on human and animal health, as well as on ecosystems. Between 2013 and 2017 and thanks to a Partnership Programme between UNESCO and the Swedish International Development Cooperation Agency (Sida), a network of over 100 Earth scientists from 29 Africa assessed the impacts of mining activities in sub-Saharan Africa. The project intended to provide crucial scientific knowledge that will contribute to understanding the factors that control cycling of pollutants from mine sites (abandoned or active) to soils, water and vegetation and the impact on the food chain. We anticipate that the results of the project will be used to improve the environmental norms in individual countries in Sub-Saharan Africa and the efficiency of governments in addressing the challenges related to the adverse effects of mining activities. The preliminary results of the project have recently been published as a Special Issue in the Journal of Geochemical Exploration. During the presentation, we intend to highlight few examples where mining activities alone or in interaction geological background are contributing to threat the ecosystem and health of neighbouring communities. We will also draw the lessons learnt from the implementation of this continental-scale project.