bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between meningitis occurrence and atmospheric conditions over the African meningitis belt
Authors: Dione Cheikh , Diouf Mame Diarra , Ogwang Bob Alex , Adefisan Elijah Adesanya , Woolnough Steve , Senghor Habib , Hirons Linda
Published: March 2020

 The alternation of seasons over tropical northern Africa is associated with the occurrence of devastating diseases such as meningitis, Lassa fever and malaria. These tropical diseases are associated with specific atmospheric conditions. Thus, meningitis is one of the most endemic diseases observed over this region with a prevalence period up to 7 months (December-June). Previous studies based on the link between atmospheric conditions and the occurrence of meningitis outbreaks have shown that this disease develops under dry and dusty atmospheric conditions which are difficult to represent in numerical weather and climate models. However, the onset, breakup, and sub-seasonal variability of meningitis outbreaks are not well documented. The objective of this study is to identify the local and synoptic drivers favoring the large occurrence of this disease over the meningitis belt in order to improve its predictability by numerical weather and climate models on intra-seasonal and seasonal timescales. This study focuses on two cases studies of meningitis epidemics over Niger in 2009 and 2015. The case study of 2009 started early with a duration of more than eight weeks. The second case study was shorter than the first one. It took three weeks and was observed at the end of the dry season. Based on ERA5 data, surface dust concentration observations and satellite data, a further analysis of the role of climate metrics on the triggering of meningitis epidemics on intra-seasonal timescales at local and large scale atmospheric conditions will be presented.
Tracking the global flows of atmospheric moisture
Authors: Tuinenburg Obbe , Staal Arie
Published: March 2020

Many processes in hydrology and Earth system science relate to moisture recycling, the contribution of terrestrial evaporation to precipitation. For example, the effects of land-cover changes on regional rainfall regimes depend on this process. To study moisture recycling, a range of moisture tracking models are in use that are forced with output from atmospheric models, but differ in various ways. They can be Eulerian (grid-based) or Lagrangian (trajectory-based), have two or three spatial dimensions, and rely on a range of other assumptions. Which model is most suitable depends on the purpose of the study, but also on the quality and resolution of the data with which it is forced. Recently, the high-resolution ERA5 reanalysis dataset has become the state-of-the-art, paving the way for a new generation of moisture tracking models. However, it is unclear how the new data can best be used to obtain accurate estimates of atmospheric moisture flows. Here we develop a set of moisture tracking models forced with ERA5 data and systematically test their performance regarding continental evaporation recycling ratio, distances of moisture flows, and footprints of evaporation from seven point sources across the globe. We report simulation times to assess possible trade-offs between accuracy and speed. Three-dimensional Lagrangian models were most accurate and ran faster than Eulerian versions for tracking water from single grid cells. The rate of vertical mixing of moisture in the atmosphere was the greatest source of uncertainty in moisture tracking. We conclude that the recently improved resolution of atmospheric reanalysis data allows for more accurate moisture tracking results in a Lagrangian setting, but that considerable uncertainty regarding turbulent mixing remains. We present an efficient Lagrangian method to track atmospheric moisture flows from any location globally using ERA5 reanalysis data and make the code for this model publicly available.
Meter-scale Measurements of VHF structure of natural leader streamers
Authors: Hare Brian , Scholten Olaf , Dwyer Joseph , Ebert Ute , Nijdam Sander ,   LOFAR CR KSP
Published: March 2020

We will present maps of negative leaders imaged in the 30-80 MHz band by the LOFAR radio telescope, which is a distributed radio telescope in the Northern Netherlands that can map lightning with meter length and nanosecond timing accuracy. These VHF images show that negative leaders emit bursts of VHF that are about 1-3 µs in duration, most likely in relation to leader stepping. The median time between bursts is around 40 μs, and the median distance is about 7.5 m. Each of these bursts contains around 3-10 discrete VHF pulses. 2/3 of these pulses are consistent with coming from the same location (with 1 meter location accuracy), and the other 1/3 come from up to 3 m away. These data are consistent with the hypothesis that these VHF bursts are due to corona flashes during leader stepping, that the discrete pulses we locate are due to the few very strongest streamers in the corona flash, and the majority of streamers in a corona flash are too weak to be observed as discrete VHF pulses. From these data, we estimate that the strongest streamers in a natural corona flash emit about 4x10-6 J in our 30-80 MHz band.
Five years of commercial microwave link network derived rainfall research in Sweden
Authors: van de Beek Remco (C.Z.) , Andersson Jafet , Olsson Jonas , Hansryd Jonas
Published: March 2020

Accurate rainfall measurements are very important in hydrology, meteorology, agriculture and other fields. Traditionally rain gauges combined with radar have been used to measure rain rates. However, these instruments are not always available. Also combining point measurements at the ground with measured reflectivities of volumes in the air to an accurate rain rate map at ground level poses challenges. Commercial microwave link networks can help in these areas as these can provide measurements at a high temporal resolution and tend to be available wherever people live, with highest network densities where most people are. They also measure precipitation along a path near ground level and offer a way to close the gap between rain gauge measurements and radar.

In this study we highlight the work SMHI has performed on deriving rain rates from commercial microwave links since 2015. This started with a pilot study in Gothenburg. The signal strengths of 364 microwave links were sampled every ten seconds and were used to create rainfall maps at a one-minute temporal resolution and 500m spatial resolution. These rain maps were then applied in a hydrological experiment and compared to rain gauge and radar measurements. The results were very promising, not only due to the high temporal and spatial resolution, but also with the accuracy of the actual measurements. The correlation was found to be equal to those of the rain gauges, while links were found to overestimate rainfall volumes on average. A demo site was created showing the one-minute rain rate maps and can be found at: https://www.smhi.se/en/services/professional-services/microweather/. Since then the methodology has been further improved and also applied within Stockholm in a new hydrological experiment. Currently new regions are being considered, as well as novel ways to merge data sources to create high quality precipitation maps. This contribution summarizes the progress to date.
Projected soil organic carbon stocks in German croplands under different climate change scenarios
Authors: Riggers Catharina , Poeplau Christopher , Don Axel , Frühauf Cathleen , Dechow René
Published: March 2020

Mineralization of soil organic carbon (SOC) is driven by temperature and soil moisture. Thus, climate change might affect future SOC stocks with implications for greenhouse gas fluxes from soils and soil fertility of arable land. We used a model ensemble of different SOC models and climate projections to project SOC stocks in German croplands up to 2099 under different climate change scenarios of the Intergovernmental Panel of Climate Change. Current SOC stocks and management data were derived from the German Agricultural Soil Inventory. We estimated the increase in carbon (C) input required to preserve or increase recent SOC stocks. The model ensemble projected declining SOC stocks in German croplands under current management and yield levels. This was true for a scenario with no future climate change (-0.065 Mg ha-1 a-1) as well as for the climate change scenarios (-0.070 Mg ha-1 a-1 to -0.120 Mg ha-1 a-1). Thereby, preserving current SOC stocks would require an increase in current C input to the soil of between 51 % (+1.3 Mg ha-1) and 93 % (+2.3 Mg ha-1). We further estimated that a C input increase of between 221 % and 283 % would be required to increase SOC stocks by 34.4 % in 2099 (4 ‰ a-1). The results of this study indicate that increasing SOC stocks under climate change by a noticeable amount will be challenging since SOC losses need to be overcompensated.
Evaluating the small-scale space time structure of rainfall in the Convection Permitting Model of UKCP18
Authors: Chen Yuting , Paschalis Athanasios , Onof Christian
Published: March 2020

Sub-daily precipitation at fine temporal resolution (~1 km2) is critical for a wide range of hydrological applications, such as flooding estimation, urban drainage design. In recent years, a step-change was given by Km-scale Convection-permitting models (CPMs), allowing for the first-time climate change projections at hydrologically relevant scales. CPMs have been now introduced in the operational climate change projections of the Met Office in the UK (UCKP18). The high-resolution hourly precipitation at a 2.2 km scales is currently available for the historical period (1980-2000) and future period (2020-2080) for the RCP8.5 scenario. It is perceived to provide a plausible tool for detailed climate impact studies. However, a question remains unanswered: is the local projection of precipitation from UKCP18 credible for hydrological use? 

To answer the question, simulated hourly precipitation from the UKCP18 for the historical period is compared statistically with the observed rainfall data. Observation rainfall was obtained from UK Met Office C-band Weather Radar network and Gridded estimates of daily areal rainfall (CEH-GEAR). These were used to assess the spatial-temporal structure of rainfall, including spatial spectra, distributions of rainfall cell sizes and intensities, and their temporal growth/decay dynamics, and rainfall extremes. The statistical evaluation was performed for all climatologically distinct regions of the UK on a seasonal basis.

The results show that hourly precipitation in UKCP18 has a realistic spatial correlation structure compared to observations. However, the extreme areal mean precipitation is overestimated, particularly at scales finer than 6.6 km. Significant differences between the size and temporal dynamics of observed and modelled rainfall cells were identified, with distinct differences amongst climate regimes, highlighting the limits of applicability of current generation CPMs for hydrological forecasting.
Factors controlling the interaction between tectonics and surface processes in convergent orogens: insight from analogue and numerical models
Authors: Reitano Riccardo , Faccenna Claudio , Funiciello Francesca , Corbi Fabio , Willett Sean
Published: March 2020

Convergent orogens are the best places on Earth for studying the interaction between surface processes and tectonics. They display the highest surface uplift rates and in turn are more likely affected by erosion. The balance between tectonics and erosion is responsible for many aspects in the evolution of a mountain belt. Despite the growth of analysis techniques, our understanding is still limited by the impossibility to observe these processes through their entire evolution. In particular, understanding how single parameters affect the system is necessary to unravel the nature of these multiple-interrelated processes.

Here we propose a new series of analogue models reproducing a simplified and scaled natural convergent orogenic system, to investigate the evolution of landscapes in which both tectonics and erosion/sedimentation are present. The growth of the orogenic wedge is driven by a rigid plate pushing the rear of the model. Deformed brittle granular material is a mixture of silica powder, glass microbeads and PVC powder. This mixture allows for the observation of both deforming structures and geomorphic features. Erosion is simulated by a water sprinkler system, providing a fine mist as precipitation which collects into simulated rivers, shaping the landscape. The model therefore allows observing the interaction between tectonics and surface processes. We analyze the model evolution monitoring oblique-view with cameras and top-view with a laser scanner. The latter is useful for measuring the mass balance between input fluxes (tectonics) and output fluxes (erosion) and in fulfilling a proper parametric study on the cause-effect relationship. The effect of different parameters on landscape evolution (e.g., precipitation rate, convergence velocity) is investigated systematically.

Our preliminary results analyze the relationship between single parameters and their effect on the models, allowing a proper definition of the role played in the landscape evolution. We also set up a benchmark with numerical models using DACI3ELVIS code in the same tectonic setting.
Impact of coseismic off-fault damage on the overall energy budget.
Authors: Thomas Marion Y. , Bhat Harsha S.
Published: March 2020

In the brittle part of the crust, deformation is usually perceived to be the result of displacement along fault planes, whose behaviors are controlled by their frictional properties. However, fault zones not only consist of a narrow fault core where slip occurs, they are also surrounded by a complex structure which is of key importance in the mechanics of faulting, hence in determining the overall energy budget. Indeed, as pointed out by the numerous field, geophysical, mechanical and laboratory observations, if the behavior of fault zones is intrinsically linked to the properties of the main sliding plane, it also depends on those of the surrounding medium.  In parallel, fault displacements may induce a substantial change in the physical properties of the surrounding medium. As a consequence, to improve our understanding of active fault zones, fault slip and the evolving physical properties must be studied as a unique system of stress accommodation and no longer as two distinct entities. To tackle this problem, we have developed a micromechanics-based constitutive model, thermodynamically argued, that can determine the inelastic behavior at macroscopic scale that arises from structural rearrangements at microscale. It is therefore the compulsory tool to emulate the strong coupling between the bulk and the fault that prevails during earthquakes. With this code, we can reproduce the strain rate sensitive, non-linear stress-strain relationship that leads to off-fault damage as a seismic event is propagating. We explore different scenarii and we show that there is a unique off-fault damage pattern associated with supershear transition of an earthquake rupture, that is also observed in the field.  We define, in return, the impact of damage on the propagation of the earthquake in itself and the generated waves. We conclude by assessing the kinetic energy, the dissipated energy and the radiated energy to define how energy is consumed within crustal systems during seismic events.
The clams before the storms: the fate of bivalve diversity during times of crisis
Authors: Collins Katie , Edie Stewart , Jablonski David
Published: March 2020

Of all the macrofossil groups, bivalves (clams, scallops, oysters and mussels) have perhaps the best global record. Known from the Cambrian, bivalves have survived every mass extinction and climate perturbation the planet has suffered. Many of the ~90 living families of bivalves with a fossil record have roots that stretch back to the Paleozoic.

This lineage longevity makes bivalves an ideal model group for studying biodiversity responses to changing climate – families have been separate for a long time, and their varied ecological roles and habitats means that the effects of climate on different biogeographic regions and ways of making a living can be teased apart. The abundance of bivalves in marine and freshwater deposits provides large specimen-level datasets for analysing survivorship across climate-event boundaries, such as the Paleocene-Eocene Thermal Maximum, a major warming event, or the end-Pliocene cooling. Bivalves have been shown to be a good proxy for much of marine benthic biodiversity, and they can give us insights into questions such as: is biodiversity response to climate perturbation predictable? What species and lineages are at risk, and can we identify them?

Not only can bivalves help us track effects of climate changes of the past thanks to their rich fossil record; they may also be a major player in human efforts towards our own future climate resilience. Bivalves today provide food for many millions of people worldwide, both in artisanal and commercial fisheries, and perform vital ecosystems services, such as water filtration, sequestration of carbon, and as both food and habitat for many other animals of all sizes. Increased aquaculture of molluscs has been postulated as a way to take more of the burden of feeding the world’s population off the terrestrial realm, and without the adverse effects of finfish farming.

This talk will discuss patterns and fluctuations of bivalve diversity through time, focusing on predictive models for survivorship across major climate transitions in the Cenozoic, and using the past behaviour of species and clades to look ahead to potential marine diversity responses to projected climate scenarios.
Detecting changes in irrigation water requirement in Central Asia under CO2 fertilization and land use changes
Authors: Tian Jing , Zhang Yongqiang
Published: March 2020

As one of the largest arid and semiarid areas in the world, Central Asia (CA) has been facing severe water crisis. Agricultural irrigation consumes most water resources there. However, it is not clear how the irrigation water requirement (IWR) varies spatially and temporally in CA, especially under CO2 fertilization and land use change. This study, for the first time, quantifies changes of IWR for two predominant crops (cotton and winter wheat) over CA under two climate change scenarios (RCP2.6 and RCP4.5, both of which consider CO2 fertilization effects) and land use projections. Our results show that without considering atmospheric CO2 concentration for estimating IWR would result in large errors and even different signs of the changes. In the future, IWR for cotton and winter wheat tends to increase in 2020s and 2040s but decrease in 2060s and 2080s under RCP2.6 and CO2 fertilization. The change magnitude is less than 5%. Under RCP4.5 and CO2 fertilization, most areas in CA exhibit an increase of less than 5%. The maximum increases of 5%-15% for cotton occur in  Tajikistan. The maximum increase of more than 50% for winter wheat occurs in Tajikistan under both climate scenarios. The IWR in Turkmenistan is most sensitive to land use change, with 33% increase compared with IWR in 2015. The other four countries have small differences (less than 10%) between 2015 and 2030. Severe water security pressure is predicted in Turkmenistan and Uzbekistan and the smallest in Tajikistan. This study provides a comprehensive evaluation of IWR for the Central Asian countries in the future and helps the decision maker for sensible water management.
Inventory, evaluation and promotion of the Essaouira Province geoheritage (Morocco): Toward a local and socio-economic sustainable development
Authors: Arrad Taha Younes , Errami Ezzoura , Ennih Nasser , Ouajhain Brahim , Ettachfini El Mostafa , Bouaouda Mohamed Said
Published: March 2020

Essaouira Province, as part of both Atlantic margin and Atlasic domain, hosts important and diverse natural attributes. The recognition of its important geological history of more than 250 million years and its tourist vocation based on the promotion of cultural, natural and human heritage are the main criteria to choose this study area. Moreover, since 2001, Essaouira has been designated a UNESCO World Heritage Site, which has long been a magnet for both national and international visitors.

The present work aims to inventory, assess and promote the major occurrences of geodiversity of Essaouira province, which are still unrecognized, fully unrevealed and unexploited, for conservation and development purposes. The inventory allows us to select the most significant geosites that are assessed through an adaptation of the method proposed by Reynard et al. (2016), based on the scientific and the additional criteria. This new approach that it is being developed and tested by our research group “Equipe de Géodynamique, Géo-éducation et Patrimoine Géologique” of the Faculty of Sciences (El Jadida), consists of the identification of the potential geosites according to a spatial hierarchy (primary, secondary, tertiary and individual geosites), while keeping the original metrics. This procedure has enabled us to assess geosites in terms of their scientific, cultural, recreational and aesthetic values: (i) Jbel Amsittene primary geosite (6 secondary and 15 tertiary geosites); (ii) Tidzi Diapir primary geosite (14 secondary geosites); (iii) Jbel Hadid primary geosite (14 secondary geosites). The remaining geosites in the province have been considered as individual geosites (21 scientific and 16 cultural). A database has been created by GIS-based implementation  and the outcomes that highlights the most relevant geosites are plotted on synthetic maps that integrate all data pertaining to the basic infrastructures.

This work provides a contribution to the Moroccan geoheritage inventory and promotion. therefore, we suggest activities to be developed, mainly in the fields of geotourism and geo-education. Indeed, these activities will allow popularizing Earth Science and catalyzing sustainable socio-economic development of rural areas while keeping and promoting their local identity. Consequently, it is important to integrate the geoheritage in the region's development-related priorities and strategies and to create a geopark in Essaouira Province.
Investigating the climate variability in the Totten area using NEMO-LIM regional model.
Authors: Van Achter Guillian , Pelletier Charles , Fichefet Thierry
Published: March 2020

The Totten ice shelf drains over 570 000 km² of East Antarctica. Most of the ice sheet that drains through the Totten ice-shelf is from Aurora Subglacial Basin and is marine based making the region potentially vulnerable to rapid ice sheet colapse.
Understanding how the changes in ocean circulation and properties are causing increased basal melt of Antarctic ice shelves is crucial for predicting future sea level rise.
In the context of the The PARAMOUR project (decadal predictability and variability of polar climate: the role of atmosphere-ocean-cryosphere multiscale interaction), we use a high resolution NEMO-LIM 3.6 regional model to investigate the variability and the predictability of the coupled climate system over the Totten area in East Antarctica.
In this poster, we will present our on-going work about the impact of landfast ice over the variability of the system. Landfast ice is sea ice that is fastened to the coastline, to the sea floor along shoals or to grouded icebergs. Current sea ice models are unable to represent very crudely the formation, maintenance and decay of coastal landfast ice. We applyed several parameterization for modeling landfast ice over the Totten ice shelf area.
First Evidence of Flux Transfer Events Caused by Mangetosheath Jets
Authors: Thor Simon , Kullen Anita , Karlsson Tomas , Raptis Savvas
Published: March 2020

Magnetosheath jets are local enhancements of dynamic pressure above the background level. Hietala et al. (2018) recently presented observational evidence of a jet collision with the magnetopause causing magnetic field line reconnection. In the present study, we show data which, for the first time, strongly indicates that magnetosheath jets can even create localized transient reconnection events, so-called flux transfer events (FTEs).

FTEs are commonly observed in cascades with an average separation time of 8-10 minutes, but may also appear as isolated events. Despite the fact that FTEs have gained major attraction during recent years, the formation process of FTEs is not yet fully understood. We showed in a recent statistical study (Kullen, Thor, and Karlsson; 2019) that isolated FTEs and FTE cascades occur during different IMF conditions and are differently distributed along the magnetopause. The results of the statistical study strongly suggest that the majority of the FTEs formed along the expected reconnection region for each respective IMF condition. However, for a subset of isolated FTEs, we proposed a different formation process. These events may have been caused by magnetosheath jets, as they occur during IMF conditions favorable for jet formation. Simulation results by Karimabadi et al. (2014) has shown that such a creation mechanism is possible. In his simulation, a magnetosheath jet collides with the magnetopause, creating an FTE.

In the present investigation, FTEs that may have been caused by magnetosheath jets were identified. To achieve this, we examined measurements from all four Cluster satellites, and searched for magnetosheath jets that appear in close proximity to FTEs listed in Wang et al. (2005)’s FTE list. Our results show that approximately 15% of isolated FTEs appear in the vicinity of jets. These FTEs are further examined based on IMF and location across the magnetopause. For two of the FTEs, the associated jet appears close to the magnetopause. We present a detailed data analysis of these two events and discuss a possible formation mechanism for the FTEs, as there is strong evidence that the two FTEs are indeed caused by jets.
Descriptors for soil development in a water limited environment of a rehabilitated open-cast mine site in south-east Australia
Authors: Pihlap Evelin , Bucka Franziska , Haberstok Tiia , Scholes Emily , Klör Tabea , Baumgartl Thomas , Kögel-Knabner Ingrid
Published: March 2020

Soil structure and soil organic matter (SOM) are closely linked characteristics describing the status of development of a soil. Their interactions affect various physical, chemical and biological soil properties and functions like water holding capacity, water infiltration, composition of the carbon pool and microbial activity. Rehabilitated soils from post mining fields are considered to have poor soil structure, low nutrient content and microbial activity. Besides disturbed soil properties, in Australia soil rehabilitation success is also influenced by climatic conditions like high evaporation rate which affects rebuilding of soil system functions. Although there are several studies looking into the development of soil properties post rehabilitation in temperate climates, the intertwined development of soil structure and quality and quantity of SOM during soil formation under water stressed environment is not clear until now.

In this study we used a space-for-time chronosequence approach in the rehabilitated open-cast mines at Yallourn Mine (Victoria, Australia) to elucidate the development of soil structure and soil organic matter after rehabilitation in a water limited environment. We selected five different fields with different rehabilitation ages (40, 22, 11, 4 and 3 years) and two mature soils that are used as grazing land. In each field we sampled 6 independent locations with stainless steel cylinders (100 cm3) at two depths of 0-4 cm and 10-14 cm.  All samples were analysed for bulk density, organic carbon (OC) and total nitrogen (TN) concentration. Selected samples were wet sieved into four aggregate size classes of <63 µm, 63-200 µm, 200-630 µm and >630 µm. For detecting OC contribution to aggregate formation, OC and TN was measured from each aggregate size fraction. This system is temporarily highly dynamic and shows different developments for bulk density and SOM stocks, which had an effect on the structure of the microbial communities. Along the space-for-time chronosequence we can observe soil structure formation with ageing and a build-up of a OM, which has a positive effect on recovering soil functionality.
Simulating riverine nutrient transport on global scale
Authors: Stacke Tobias , Hagemann Stefan , Romero-Mujalli Gibran , Hartmann Jens , Thomas Helmuth
Published: March 2020

The currently ongoing CMIP6 simulations feature Earth System Models with interactively coupled components for atmosphere, ocean and land surface. Water, energy and momentum between these components are exchanged conservatively. This is crucial to compute climate interactions and their feedbacks consistently. Currently, the representation of biogeochemical cycles in land surface and ocean models is advancing including not only a carbon cycle but also processes based on nutrients like nitrogen or phosphorus. Some land surface models (LSM) already compute leaching of such constituents from the soil, and some ocean models (OM) consider nutrient influx from the land for a number of processes, e.g. biological activity. However, the OMs usually use observed data as input instead of the nutrient loads computed by the LSMs. This setup cannot represent the effects of climate or land use change on nutrient availability and therefore limits the applications of ESMs in respect to climate change impacts.

For this reason, we are extending our hydrological discharge model, the HDM, to not only transport water but also other constituents. The HDM is an established component of regional (GCOAST, ESM ROM, Reg-CM-ES) as well as global (MPI-ESM) climate models but also applicable as stand-alone model. In a first step, only inert transport is simulated without considering any chemical reactions or biological transformation during river flow. The transport is realized using the same linear cascade infrastructure as used for water transport. However, a successful offline validation of these new features does not only require a realistic routing scheme and consequently the representation of the most important reactions during transport, but also the generation of sensible input data either from large scale models or from observations. In our presentation, we will outline the state of this work together with the compiled input dataset.
Remote Sensing based comparative analysis of cotton irrigation and water productivity in Pakistan, Turkey and Uzbekistan
Authors: Usman Muhammad , Mahmood Talha , Conrad Christopher
Published: March 2020

Textile products made with cotton produced in Pakistan, Turkey, and Uzbekistan are largely imported to European markets. This is responsible for high virtual water imports from these countries and thus puts immense pressure on their water resources, which is further extravagated due to climate change and population growth. The solution to combat the issue, on one hand, is to cut water usage for cotton irrigation, and on the other hand, to increase water productivity. The biggest challenge in this regard is the correct quantification of consumptive water use, cotton yield estimation and crop water productivities at a finer spatial resolution on regional levels, which is now possible by utilizing remote sensing (RS) data and approaches. It can also facilitate comparing regions of interest, like in this study, Pakistan, Turkey, and Uzbekistan by utilizing similar data and techniques. For the current study, MODIS data along with various climatic variables were utilized for the estimation of consumptive water use and cotton yield estimation by employing SEBAL and Light Use Efficiency (LUE) models, respectively. These estimations were then used for working out water productivities of different regions of selected countries as case studies. The results show that the study area in Turkey achieved maximum cotton water productivity (i.e. 0.75 - 1.2 kg.m-3) followed by those in Uzbekistan (0.05 – 0.85 kg.m-3) and Pakistan (0.04 – 0.23 kg.m-3).  The variability is higher for Uzbekistan possibly due to agricultural transition post-soviet-union era. In the case of Pakistan, the lower cotton water productivities are mainly attributed to lower crop yields (400 – 1200 kg.ha-1) in comparison to Turkey (3850 – 5800 kg.ha-1) and Uzbekistan (450 – 2500 kg.ha-1). Although the highest crop water productivity is achieved for the study region in Turkey, there is still potential for further improvement by introducing on-farm water management. In the case of the other two countries, especially for Pakistan, major improvements are possible through maximizing crop yields. The next steps include comparisons of the results in economic out-turns.
Exploring the trends and potential drivers of surface ozone in eastern China in 2015-2018
Authors: Yang Ning , Bai Yanru , Zhu Yong , Ma Nan , Wang Qiaoqiao
Published: March 2020

In the last six years, China has experienced significant improvement in air quality due to great emission reduction efforts. However, ozone concentrations are still slowly increasing in three major regions of eastern China, respectively Jing-Jin-Ji(JJJ), Yangtze River Delta region(YRD) and Pearl River Delta region(PRD). It is shown from the 2015-2018 national urban air quality real-time release platform that the surface ozone in JJJ, YRD and PRD has increased each year and reached the highest in 2018. The monthly ozone concentration peaked in June in almost all cities of JJJ, while it had multiple peaks in other two regions (summer and autumn in YRD - and February, May and September in PRD). Simulation with a chemical transport model(GEOS-Chem) indicates that the formation of ozone is affected by the optical properties of PM2.5 and also the heterogeneous uptake of N2O5 on sea salt aerosol.
The Buried Grand Canyon in Egypt: Structural controls on the Neogene River Nile
Authors: Abdelkhalek Ali , Kley Jonas , Hammed Mohamed , Ali Ahmed Saied
Published: March 2020

The origin and intricate history of the River Nile are still widely disputed. Some studies have claimed that the present course of the Nile has formed at ~7-5 Ma, while others have suggested a much longer evolution. We proposed earlier that the southern and central segments of the River Nile in Egypt have originally evolved along a NW trending short-lived rift that was formed by NE-SW extension at ~25-23 Ma, and abandoned at an early stage. Here we focus on the development of the northern segment of the river, which we interpret as having both a relatively young age (~7-6 Ma) and different tectonic evolution. Gravity models and 3D seismic and well data show the presence of a deeply buried canyon west of the northern modern River Nile, 120 km southwest of Cairo, and approximately parallel to its present-day valley with a predominant NNE-NE course. The U-shaped canyon is up to 13 km wide and attains a maximum depth of around 1,900 meters, about as deep as the Grand Canyon of the Colorado River in Arizona, USA. The canyon was cut into a rising plateau along deep-seated NNE to NE-striking faults that formed at ~90-80 Ma as secondary shears to the main structures of the WNW oriented Cretaceous Beni-Suef rift and possibly have been reactivated at ~14 Ma with the origin of the Gulf of Aqaba-Dead Sea NNE sinistral transform plate boundary. The deeply incised canyon formed as a result of severe erosion due to significant sea level drop and desiccation of the Mediterranean in late Miocene time (Messinian Crisis ~7-6 Ma), which was accompanied by continued progressive uplift of the north-eastern Egyptian terrain[KJ1] . [2] The ancestral river excavated and widened a vast braided channel[3]  that cut deeply into Turonian-Campanian sediments in the Beni-Suef basin. The canyon attained its maximum depth by ~5 Ma, and subsequently it was filled by six successive clastic-dominated units of different fluvial facies.[4] 
Emplacement mechanisms of a dyke swarm across the Brittle-Ductile transition
Authors: Kjøll Hans Jørgen , Galland Olivier , Labrousse Loic , Andersen Torgeir B.
Published: March 2020

Dykes are the main magma transport pathways through the Earth’s crust and, in volcanic rifts, they are considered the main mechanism to accommodate tectonic extension. Most models consider dykes as hydro-fractures propagating as brittle tensile, mode I cracks opening perpendicular to the least principal stress. This implies that dykes emplaced in rifts are expected to be sub-vertical and accommodate crustal extension. Here we present detailed field observations of a well-exposed dyke swarm that formed near the brittle-ductile transition at a magma-rich rifted margin during opening of the Iapetus Ocean. It was related to a ca 600 million year-old large igneous province. Our observations show that dykes were not systematically emplaced by purely brittle deformation and that dyke orientation may differ from the typical mode 1 pattern. Distinct dyke morphologies related to different emplacement mechanisms have been recognized including: 1) Brittle dykes that exhibit straight contacts with the host rock, sharp tips, and en-echelon segments with bridges exhibiting angular fragments; 2) Brittle-ductile dykes with undulating contacts, rounded tips, folding of the host rock and contemporaneous brittle and ductile features; 3) Ductile “dykes” with rounded shapes and mingling between partially molten host rock and the intruding mafic magma. The brittle dykes exhibit two distinct orientations separated by ~30° that are mutually cross-cutting, demonstrating that the dyke swam did not consist of only vertical sheets oriented perpendicular to regional extension, as expected in rifts. By using the host-rock layers as markers, a kinematic restoration to quantify the average strain accommodating the emplacement of the dyke complex was performed. This strain estimate shows that the dyke swarm accommodated >100% horizontal extension, but also 27% vertical thickening. This suggests that the magma influx rate was higher than the tectonic stretching rate, which imply that magma was emplaced forcefully, as supported by field observations of the host-rock deformation. Finally, observations of typical “brittle” dykes that were subsequently deformed by ductile mechanisms as well as dykes that were emplaced by purely ductile mechanisms suggest that the fast emplacement of the dyke swarm triggered a rapid shallowing of the brittle-ductile transition. The abrupt dyke emplacement and associated heating resulted in weakening of the crust that probably facilitated the continental break-up, which culminated with opening of the Iapetus Ocean.
Anthropogenic pollutants and biomarkers for the identification of 2011 Tohoku-oki tsunami deposits (Japan)
Authors: Schwarzbauer Jan , Bellanova Piero , Frenken Mike , Jaffe Bruce , Szczuciński Witold , Reicherter Klaus
Published: March 2020

Organic geochemistry is commonly used in environmental studies. In tsunami research, however, its application is in its infancy and rarely used. Tsunami deposits may also be able to be characterized by organic-geochemical parameters as tsunami transports not only particulate sedimentary material from marine to terrestrial areas (and vice versa), but also associated organic material. Recently, more attention has been given to the usage of natural organic substances (biomarkers) for tsunami identification. We present results of biomarkers and anthropogenic markers detected in deposits of the 2011 Tohoku-oki tsunami on the Sendai Plain, Japan (Bellanova et al., 2020). As the tsunami inundated the coastal lowland up to 4.85 km inland, sediments from various sources were eroded, transported and deposited across the area. This led to the distribution of biomarkers from different sources across the Sendai Plain creating a unique geochemical signature in the tsunami deposits. The tsunami also caused destruction along the Sendai coastline, leading to the release of large quantities of environmental pollutants (e.g., fossil fuels, tarmac, pesticides, plastics, etc.) that were distributed across the inundated area. Corresponding anthropogenic markers, represented by three main compound groups (polycyclic aromatic hydrocarbons, pesticides, and halogenated compounds), were preserved in tsunami deposits (at least until 2013, prior to land clearing). Organic compounds from the tsunami deposits (Tohoku-oki tsunami) were extracted from tsunami sediment and compared with the organic signature of unaffected pre-tsunami samples using gas chromatography-mass spectrometry (GS/MS) based analyses. Their concentrations differed significantly from the pre- and post-tsunami background contamination levels. Organic proxy concentrations differ also for sandy and muddy tsunami deposits due to various factors (e.g., preservation, dilution, microbial alteration).

As tsunami research advanced over the last decades so did the methods used to gain more and more information on the past events. Developing new methods for the identification and characterization of tsunami deposits for recent, historic or paleo events is crucial. Every piece of additional information we gain from event deposits leads us a step further to a better understanding of mechanisms acting during a tsunami. This will help to improve countermeasures and relief efforts. Anthropogenic markers and biomarkers, because of their high source specificity and good preservation potential, have the potential to be a valuable proxy in future studies of tsunami deposits and provide information about sediment sources and transport pathways.
Urban Distributed Acoustic Sensing Using In-Situ Fibre Beneath Bern, Switzerland
Authors: Smolinski Krystyna , Paitz Patrick , Bowden Daniel , Edme Pascal , Kugler Felix , Fichtner Andreas
Published: March 2020

Anticipating the risks natural hazards pose to an urban environment requires an understanding of the shallow Earth structure of the region. While urban infrastructure often hinders the deployment of a traditional seismic array, Distributed Acoustic Sensing (DAS) technology facilitates the use of existing telecommunication fibre-optic cables for seismic observation, with spatial resolution down to the metre scale.

Through collaboration with the SWITCH foundation, we were able to use existing, in-situ fibres beneath Bern, Switzerland for seismic data acquisition over two weeks, covering a distance of 6 km with a spatial resolution of 2 m. This allowed for not only real-time visualisation of anthropogenic noise sources (e.g. road traffic), but also of the propagation of resulting seismic waves.

Data is analysed in the time and frequency domain to explore the range of signals captured and to assess the consistency of data quality along the cable. The local velocity structure can be constrained using both noise correlations and deterministic signals excited by traffic.

Initial results reveal the ability of DAS to capture signals over a wide range of frequencies and distances, and show promise for utilising urban DAS data to perform urban seismic tomography and hazard analysis.
Integrated approach for evaluating sources and apportionment of agro-contaminants in soil and water bodies
Authors: Adu-Gyamfi Joseph , Heng Lee , Halder Janine
Published: March 2020

Water pollution from agricultural activities has direct negative impacts on human health, as the well-known blue-baby syndrome —a potentially fatal illness —deriving from nitrate intake in infants. Inefficient farming practices, farming systems discharge large quantities of agrochemicals, organic matter, drug residues, sediments, and saline drainage into water bodies results in pollution poses demonstrated risks to aquatic ecosystem, human health and productive activities including agriculture. In order to design effective remediation strategies there is a need to target sources of excess nutrients, and sediments in an efficient way. Standard operating procedures (SOP) that provides step-by step instructions on how to collect, prepare and prepare soil samples from agriculture watersheds for multi-isotope analysis were evaluated and standardized in agricultural catchments in Asia (Australia, China, India, Sri Lanka, Vietnam), Europe (Austria, France, Germany, Ireland, Romania, Slovenia, Switzerland, United Kingdom) and Africa (Morocco and Ghana) in a coordinated research project managed by the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The δ18O, δ2H, δ15N-NO3, δ18O-NO3 stable isotope values in water samples were used to apportion the contributions of the different sources (chemical fertilizers, organic fertilizers from livestock, and rural domestic sewerage). The compound specific isotope analysis (CSIA)-based monitoring approach (δ13C and δ15N) was used to evaluate in-situ degradation, transport, transformation and fate of pesticides. Information gained will fill knowledge gaps for catchment scale predictive models and provide guidelines and decision trees to develop an isotopic analytical toolbox that could be adapted to different agricultural management situations.
Recent environmental change in a marine protected area as reflected by sediment proxy data.
Authors: Polovodova Asteman Irina , Andersen Thorbjørn Joest , Linders Torsten , Nordberg Kjell , Van Nieuwenhove Nicolas
Published: March 2020

The Koster Trench is the deepest part of the Kosterfjord (Skagerrak, North Sea), which stretches southward along the west coast of Sweden. Since 2009 Kosterfjord has been included in the Marine Protected Area Kosterhavet National Park due to the presence of cold-water coral reefs. In this study we present multiproxy data from the sediment core KSK12-01D taken in the southern part of the Koster Trench. The core has been dated by 137Cs and was subject to bulk geochemistry (TOC, C/N and heavy metals: Ni, Cu, Zn, As, Cd and Pb) and micropaleontological (benthic foraminifera, dinocysts and selected palynomorphs) analyses. Results show that the core is an archive for the environmental changes that took place between ~1988 and 2012. Both TOC and heavy metals indicate high/good to moderate ecological quality status, as defined by the Swedish Environmental Protection Agency. Dinocysts suggest a major change occurring in the upper water column around 2002. The cysts of Pentapharsodinium dalei peak around 1992 and shows overall slightly higher relative abundances between 1988 and 2002. Increased abundance of cysts produced by Protoceratium reticulatum (i.e. Operculodinium centrocarpum sensu Wall and Dale 1966), cysts produced by Biecheleria baltica and heterotrophic dinoflagellates, oligotrichids, pollen and spores characterise the upper core part deposited from 2002 to 2012. Furthermore, there is a clear increase of calcareous Alexandrium cysts in the top of the core (~2008-2012). Benthic foraminifera show a major faunal change reflected in a drastic increase of agglutinated species (mainly Textularia earlandi) from 2007 towards present day, while the lower part of the core (1988-2007) is dominated by calcareous species (Stainforthia fusiformis, Epistominella exigua, Cassidulina laevigata, Bulimina marginata andHyalinea balthica). Overall, the changes in the dataset suggest an increased freshwater input or a higher river/land runoff, as supported by a local climate and hydrography data showing increasing precipitation and particulate organic carbon in the surface waters over the time period covered by our record.