bluuebunny/crossref_metadata_2025 huggingface dataset:
A daily water balance model with a dynamic wetted area for estimating drainage from soil moisture observations in an irrigated orchard
Authors: Bruggeman Adriana , Siakou Melpo , Eliades Marinos , Djuma Hakan , Zoumides Christos
Published: March 2021

Drainage below the root zone of irrigated crops and trees is often an unknown component of the water balance. This drainage water could recharge underlying aquifers and flow to streams and is not part of water consumed by crops, as used in water productivity computations. Drainage from fields with irrigation systems that wet only part of the soil is difficult to estimate. The objective of the research was to develop a water balance model with a dynamic wetted area for analyzing soil water balance components from daily soil moisture observations. The method was applied in an olive orchard in Cyprus, with approximately 35% canopy cover. Soil moisture sensors (SMT100, Truebner and 5TM, Decagon) were installed at six trees, at 10-, 20-, 40- and 60-cm depth, approximately 90 cm from the trunk of the tree. Soil moisture was recorded hourly. The trees were irrigated weekly, with a single spaghetti tube with a discharge rate of approximately 135 L/hr. Daily reference evapotranspiration was computed with the Penman-Monteith equation from meteorological observations recorded inside the orchard (WS500, Lufft). Rainfall was measured with a tipping bucket rain gauge (15189, Lambrecht).

The model computes a daily volumetric water balance for the canopy area of the tree. During the irrigation season, soil moisture observations were assumed to represent the soil volume wetted by irrigation. Drainage below the 70-cm root zone occurred when soil moisture exceeded the field capacity, as derived from hourly observations. A canopy-area crop coefficient (Kcc-max) was estimated for all irrigation days without drainage by minimizing the sum of the daily evapotranspiration in excess of the maximum evapotranspiration (Kcc-max ETo). This one-sided error was controlled by maintaining a positive difference between Kcc-max and Kcc the day after irrigation. Wetted areas were subsequently computed for all irrigation days without drainage. For irrigation days with soil moisture above field capacity, the wetted area was adjusted manually, such that drainage was smaller on the second day than on the irrigation day, using a Kcc-max for both days. During the May to November 2019 irrigation season, drainage was 8 mm over the field area, for a field capacity of 36%, a Kcc-max of 1.3, and an error of 16 mm. Assuming a field capacity of 38%, drainage was 3 mm over the field area, with a Kcc-max of 1.4, and an error of 17 mm. Overall, the model provided a quick and robust way of estimating the irrigation water balance components.

This research has received financial support from the ERANETMED3 program, as part of the ISOMED project (Environmental Isotope Techniques for Water Flow Accounting), funded through the Cyprus Research and Innovation Foundation.
Past variations of Lake Sevan (Armenia, lesser Caucasus): documenting climate triggers for the Near East and delivering insights for a sustainable management
Authors: Joannin Sebastien ,   Sevan-upians
Published: March 2021

To understand the long-term patterns of atmospheric circulation in Eurasia, current paleoclimatic reconstruction syntheses lack accurate data for the Near East. In this semi-arid zone, precipitation is the key factor to be studied that strongly controls ecosystems and human societies. Few data are available from Lake Sevan (1900.52 m above sea level, 1,279 km², 38.2 km3 as of January 1, 2021), the largest fresh-water lake in the Near East, whose past level variations may document seasonal to millennial precipitation changes.

We present here the preliminary results of the interdisciplinary Sevan-up Project. Its ambition is to develop a high resolution lake level reconstruction (which is expected to be preserved from the influences of long ecological processes and from human activities) and other climatic proxies (from pollen and molecular biomarker) in view to quantify precipitation changes during the Holocene.

The Early Holocene climate characteristics (strong seasonality) and environment (prevalence of steppe ecosystems) may raise an analogous model of future conditions in the Near East which will be affected by enhanced continentalism. The study of littoral and deep sedimentary deposits will potentially reveal the consequences of past variations in lake levels on its hydrodynamic functioning and trophic status. These results will give crucial information on how to improve the lake's water management with the goal to reach a sustainable use and a better ecological state. Indeed, seasonal stratification onsets and trophic status dramatically changed since the man-made water-level fall during the Soviet times (40% of its volume).
Adaptation strategies can offset rising river flood risk in Europe
Authors: Dottori Francesco , Mentaschi Lorenzo , Bianchi Alessandra , Alfieri Lorenzo , Feyen Luc
Published: March 2021

River flooding is the costliest natural disaster in Europe. Global warming and continued development in flood prone areas will progressively increase river flood risk. Direct damages from flooding could become six times present losses by the end of the century in case of no climate mitigation and adaptation. Keeping global warming well below 2°C would halve these impacts. Adequate adaptation strategies can further substantially reduce future flood impacts. In particular, implementing building-based damage reduction measures and reducing flood peaks using retention areas can lower impacts in a cost-efficient way in most EU countries, even to flood risk levels that are lower than today. Restoring natural wetlands and floodplains to retain excess water also improves the state of water and ecosystems.
Mean Sea Level and Tidal Change in Ireland since 1842: A case study of Cork
Authors: McCarthy Gerard , Pugh David , Edwards Robin , Hogarth Peter , Woodworth Philip
Published: March 2021

Mean sea levels are changing worldwide, and local tidal changes have been widely reported. Knowledge of regional changes in mean sea level, and local changes in tides are crucial to inform effective climate adaptation. An essential element of this is the availability of accurate observations of sea level. Sea level data in the Republic of Ireland, prior to the establishment of the National Tide Gauge Network in the mid-2000s, is very limited but belies a wealth of historical data available in archival form. In this study, we digitize records located in Cork Harbour, Ireland from 1842 and show how short duration (6 weeks), high quality data, with a large interval (177 years) to the present, can accurately inform tidal and mean sea level changes. We consider error sources in detail and estimate that for M2 the accuracy of these historical measurements is 1% and 2 minutes for amplitude and timing respectively; and our mean sea level estimates are accurate to the centimetre level. Our results show remarkable tidal stability with a 2% change in the amplitude of the M2 component and 4 minute change in the phase over a period of 177 years; and a mean sea level rise of 41 cm in the Cork Harbour area since 1842, approximately in line with global mean sea level trends plus local glacial isostatic adjustment. More broadly, we show that with careful seasonal, nodal, and atmospheric corrections, together with good knowledge of benchmark provenance, these historic, survey-oriented data can accurately inform of sea level changes.
Coastal sea level changes in Africa from retracked Jason altimetry over 2002-2020
Authors: Gouzenes Yvan , Cazenave Anny , Léger Fabien , Birol Florence , Passaro Marcello , Nino Fernando , Calafat Francisco , Shaw Andrew , Legeais Jean-François , Benveniste Jérome
Published: March 2021

Climate-related sea level changes in the world coastal zones result from the superposition of the global mean rise due to ocean warming and land ice melt, regional changes mostly caused by non-uniform ocean thermal expansion and salinity changes, and small-scale coastal processes (e.g., shelf currents, wind & waves changes, fresh water input from rivers, etc.). So far, satellite altimetry has provided global gridded sea level time series up to 10-15 km to the coast only, preventing estimation of sea level changes very close to the coast. In the context of the ESA Climate Change Initiative coastal sea level project, we have developed a complete reprocessing of high-resolution (20 Hz) Jason-1, 2 and 3 altimetry data along the world coastal zones using the ALES (Adaptative Leading Edge Subwaveform) retracker combined with the XTRACK system dedicated to improve geophysical corrections at the coast. Here we present coastal sea level trends over the period 2002-2020 along the whole African continent. Different coastal sea level trend behaviors are observed over the study period. We compare the computed coastal trends in Africa with results we previously obtained in other regions (Mediterranean Sea, Northeastern Europe, north Indian Sea, southeast Asia and Australia).
Comparison of soil CO2 emissions from three different tillage methods on chernozem soil
Authors: Dencső Márton , Horel Ágota , Bakacsi Zsófia , Tóth Eszter
Published: March 2021

Tillage practices influence soil CO2 emissions, hence many research investigate the long-term effects of conservation and conventional tillage methods e.g. ploughing and no-tillage on soil greenhouse gas emission.

The experiment site is an 18-years-old long-term tillage trial established on chernozem soil. During 2020, we took weekly CO2 emission measurements in the mouldboard ploughing (MP), no-tillage (NT), and shallow cultivation (SC) treatments Tillage depth was 26-30 cm, 12-16 cm and 0 cm in the cases of MP, SC and NT respectively. The experiment was under wither oat cultivation.

We investigated the similarity in the CO2 emission trends of SC to MP or NT treatments. Besides CO2 emission measurements, we also monitored environmental parameters such as soil temperature (Ts) and soil water content (SWC) in each treatment.

During the investigated year (2020 January - December) SC had higher annual mean CO2 emission (0.115±0.083 mg m-2 s-1) compared to MP (0.099±0.089 mg m-2 s-1) and lower compared to NT (0.119±0.100 mg m-2 s-1). The difference of the CO2 emissions was significant between SC and MP (p<0.05); however, it was not significant between SC and NT (p>0.05) treatments. The Ts dependency of CO2 emission was moderate in all treatments. CO2 emissions were moderately depended on SWC in MP and SC, and there was no correlation between these parameters in NT.

The annual mean CO2 emission of the SC treatment was more similar to the NT, than to the MP treatment.
A simple model to assess the long term fate of the AMOC
Authors: Wood Richard
Published: March 2021

Studies with global climate models over the past 25 years have shown a range of long-term responses of the Atlantic Meridional Overturning Circulation (AMOC), in response to scenarios in which greenhouse gases are increased then eventually stabilised at some value, possibly after temporarily overshooting that value. AMOC responses include stabilisation at weaker than the pre-industrial level, rapid recovery following a period of quasi-steady weak circulation, overshooting to stronger than pre-industrial strength, or tipping to a quasi-permanent weak state. While many of these studies have gained insight into the mechanisms behind their individual model behaviour, no overarching understanding exists of what determines how a particular model will respond.   

We present a simple AMOC model suitable to characterise the different possible long-term responses, and use it as a (partially) unifying framework to show how the different behaviours can arise from a competition between thermal and haline feedbacks. The results are relevant to defining ‘safe mitigation pathways’ that avoid or reduce the risk of AMOC tipping or potentially dangerous overshoots.
Alternative crops for a changing climate in Switzerland
Authors: Heinz Malve , Romppainen-Martius Olivia , Holzkämper Annelie
Published: March 2021

Rising temperatures, shifts in precipitation patterns and longer dry periods provoke a need for better adapted crops in Switzerland to maintain agricultural productivity in the long term. The aim of this work was to identify plants with a high climatic suitability in the future. A simple mechanistic model (ecocrop) was applied to determine suitability for different time periods under RCP scenarios 4.5 and 8.5. The model considers temperature and precipitation ranges. From a pool of 600 edible plants, 21 plants were identified that would benefit from progressing climate change in terms of average climatic yield potentials. In addition, these plants were found to have a high nutritional quality and could thus be seen as good candidate crops to expand the portfolio of cultivated crops in Switzerland in efforts to adapt to climate change and maintain or even increase food productivity in a future climate. The potentials of selected crops are discussed in terms of cultivation requirements, spatial suitability, and market potentials.
Assessment of tidal range changes in the North Sea from 1958 to 2014
Authors: Jänicke Leon , Ebener Andra , Dangendorf Sönke , Arns Arne , Schindelegger Michael , Niehüser Sebastian , Haigh Ivan D. , Woodworth Philip , Jensen Jürgen
Published: March 2021

Tide gauges throughout the North Sea basin show significant changes in the local tidal regime since the mid-20th century, especially in the German Bight area. These changes were analyzed within the DFG-funded project TIDEDYN (Analyzing long term changes in the tidal dynamics of the North Sea, project number 290112166) and the final results were recently published in Jänicke et al. (2020, https://doi.org/10.1029/2020JC016456).

In this paper, we document an exceptional large-spatial scale case of changes in tidal range in the North Sea, featuring pronounced trends between -2.3 mm/yr at tide gauges in the UK and up to 7 mm/yr in the German Bight between 1958 and 2014. These changes are spatially heterogeneous and driven by a superposition of local and large-scale processes within the basin. We use principal component analysis to separate large-scale signals appearing coherently over multiple stations from rather localized changes. We identify two leading principal components (PCs) that explain about 69% of tidal range changes in the entire North Sea including the divergent trend pattern along UK and German coastlines that reflects movement of the region’s semidiurnal amphidromic areas. By applying numerical and statistical analyses, we can assign a baroclinic (PC1) and a barotropic large-scale signal (PC2), explaining a large part of the overall variance. A comparison between PC2 and tide gauge records along the European Atlantic coast, Iceland and Canada shows significant correlations on time scales of less than 2 years, which points to an external and basin-wide forcing mechanism. By contrast, PC1 dominates in the southern North Sea and originates, at least in part, from stratification changes in nearby shallow waters. In particular, from an analysis of observed density profiles, we suggest that an increased strength and duration of the summer pycnocline has stabilized the water column against turbulent dissipation and allowed for higher tidal elevations at the coast.

We would like to present these research results and the content of the paper (cf. Jänicke et al., 2020) at vEGU21, hoping to encourage subsequent questions and further discussions.
Low-altitude magnetic reconnection events as possible drivers of Jupiter’s polar auroras
Authors: Masters Adam , Dunn William , Stallard Tom , Manners Harry , Stawarz Julia
Published: March 2021

Charged particles impacting Jupiter’s atmosphere represent a major energy input, generating the most powerful auroral emissions in the Solar System. Most auroral features have now been explained as the result of impacting particles accelerated by quasi-static electric fields and/or wave-particle interactions in the surrounding space environment. However, the reason for Jupiter’s bright and dynamic polar regions remains a long-standing mystery. Recent spacecraft observations above these regions of “swirl” auroras have shown that high-energy electrons are regularly beamed away from the planet, which is inconsistent with traditional auroral drivers. The unknown downward-electron-acceleration mechanism operating close to Jupiter represents a gap in our fundamental understanding of planetary auroras. Here we propose a possible explanation for both the swirl auroras and the upward electron beams. We show that the perturbations of Jupiter’s strong magnetic field above the swirl regions that are driven by dynamics of the distant space environment can cause magnetic reconnection events at altitudes as low as ~0.2 Jupiter radii, rapidly releasing energy and potentially producing both the required downward and observed upward beams of electrons. Such an auroral driver has never before been postulated, resembling physics at work in the solar corona.
Predicting preferential flow and water table fluctuations in karst systems using film-flow theory and source-responsive models
Authors: Noffz Torsten , Kordilla Jannes , Kavousi Alireza , Reimann Thomas , Sauter Martin , Liedl Rudolf
Published: March 2021

The locally focused dissolution of the rock material (e.g., below dolines and dry valleys) in karst systems and in general percolating clusters of fractures in consolidated aquifer systems trigger the development of preferential flow paths in the vadose zone. Rainfall events may initiate rapid mass fluxes via macropores and fractures (e.g., as gravitationally-driven films) that lead to source-responsive water table fluctuations and comparably short residence times within the vadose zone. The degree of partitioning into a slow diffuse infiltration component and a rapid localized part depends, amongst others, on the hydraulic interaction of porous matrix and fracture domain as well as the geometrical characteristics of the fracture systems (e.g., persistence, connectivity) that are often difficult to obtain or unknown under most field conditions. Given their importance in water-resource management, specifically in arid and semi-arid regions (e.g., Mediterranean), it is desirable to recover such infiltration dynamics in porous-fractured systems with physically-based yet not overparameterized models. Here, we simulate water table fluctuations in a karst catchment in southwest Germany (Gallusquelle) using a source-responsive film flow model based on borehole and precipitation data. The model takes into account interfacial connectivity between slow and fast domain as well as phreatic zone discharge via classical recession analysis. This case study shows the potential importance of preferential flows while modeling water table responses in karst systems and recognizes the need for formulations other than those applied for a diffuse bulk fractured domain where infiltration patterns are assumed to be homogeneous without formation of infiltration instabilities along preferential pathways.
A fusion of UAVs, digital cameras and micrometeorology to quantify the link between phenology and the carbon balance of a temperate peatland
Authors: Simpson Gillian , Helfter Carole , Nichol Caroline , Wade Tom
Published: March 2021

Peatland ecosystems are historical carbon sinks of global importance, whose management and restoration are becoming an increasingly popular approach to reach climate change targets via natural capital. However, the Net Ecosystem Exchange (NEE) of carbon dioxide (CO2) can exhibit substantial variability on seasonal and inter-annual timescales, with some peatlands shifting from being a sink to a source of CO2 between years. This variability is due to the complex interaction between factors such as meteorology and phenology, which are both known to control a peatland’s net carbon sink strength. An improved understanding of these two drivers of peatland carbon cycling is needed to allow for better prediction of the impact of climate change on these ecosystems. This task requires us to study these environmental controls at multiple spatial and temporal scales. The role of vegetation in regulating NEE however, can be difficult to determine over shorter timescales (e.g. seasonal) and especially in peatland landscapes, which typically display strong spatial heterogeneity at the microsite scale (< 0.5 m). Digital phenology cameras (PhenoCams) and Unmanned Aerial Vehicles (UAVs), offer novel opportunities to improve the temporal resolution and spatial coverage of traditional vegetation survey approaches. UAVs in particular are a more flexible, often cheaper alternative to satellite products, and can be used to collect data at the sub-centimetre scale. We employ PhenoCam imagery and UAV surveys with a Parrot Sequoia multispectral camera to map vegetation and track its phenology using vegetation indices such as the Normalised Difference Vegetation Index (NDVI) over the course of two growing seasons at Auchencorth Moss, a Scottish temperate peatland. By combining this digital camera imagery with in-situ NEE measurements (closed chambers and eddy-covariance) and meteorological data, we seek to quantify the impact of weather and phenology on carbon balance at the site.
Middle-to late Holocene environmental changes based on a multi-proxy lagoonal record, Klisova lagoon, Greece
Authors: Emmanouilidis Alexandros , Panagiotopoulos Konstantinos , Kouli Katerina , Avramidis Pavlos
Published: March 2021

Coastal wetlands are dynamic environments prone to climatic and anthropogenic forcing and ideal settings to study past climatic and environmental changes.  In the eastern Mediterranean region and particularly in Greece, the climate presents high spatiotemporal diversity, while human activity is a significant factor in shaping the landscape. This study presents a sediment record from Klisova lagoon, situated in central Greece, at the eastern part of Messolonghi lagoon complex. The area is recorded from antiquity to have great anthropogenic activity. The paleoenvironmental synthesis was based on standard sedimentological analysis (grain size, TOC, magnetic susceptibility), joint micropaleontological and palynological analysis, X-ray Fluorescence scanning, and radiocarbon dating. The Bayesian age-depth model is based on radiocarbon dating and yields an age of 4700 cal BP for the base of the recovered sediment sequence. For the last 4700 years, the freshwater influx, the progradation of the Evinos river delta and related geomorphological changes control the environmental conditions (e.g. depth and salinity) in the lagoon system. Prior to 4000 cal BP, a relatively shallow water depth, significant terrestrial/freshwater input and increased weathering in the lagoon area are inferred. Elemental proxies and increased dinoflagellate and foraminifera abundances, which indicate marine conditions with prominent freshwater influxes, point to the gradual deepening of the lagoon recorded at the drilling site up to 2000 cal BP. The marine and freshwater conditions equilibrium sets at 1300 cal BP, and the lagoonal system seems to reach its present state. Maxima of anthropogenic pollen indicators during the Mycenaean (~3200 cal BP), Hellenistic (~ 2200 cal BP) and Late Byzantine (~ 800 cal BP) periods suggest intervals of increased anthropogenic activities in the study area.  
Visualizing Sedimentary Condensation , Dilution, and Erosion using Shiny Apps
Authors: Hohmann Niklas , Jarochowska Emilia
Published: March 2021

Fossil accumulations can be generated by (1) high input of organism remains or (2) by low sedimentation rates, reducing the volume of sediment between individual fossils. This creates a paradox, in which shell beds may form in environments with low biomass production. This effect of sedimentary condensation on fossil abundance is easy to understand, however, its implications are hard to grasp and visualize.

We present the shellbed condensator ( https://stratigraphicpaleobiology.shinyapps.io/shellbed_condensator/ ), a web application that allows to interactively visualize and animate the effects of sedimentary condensation and erosion on fossil abundance and proxies recorded by the sedimentary record. It is an adaptation of the seminal computer simulation by Kidwell (1985). The application is written in R Software and uses the shiny package for the construction of the web interface and the DAIME package for the sedimentological model (Hohmann, 2021). It allows creating stratigraphic expressions and age models for combinations of fossil input and sedimentation rates defined by the user.

To assess the utility of shiny apps for teaching purposes, we examine student understanding of sedimentary condensation after unsupervised studying and after unsupervised usage of the app. Due to their strong visual and interactive components, shiny apps are a powerful and versatile tool for science communication, teaching, self-study, the visualization of large datasets, and the promotion of scientific findings.

 
Surface and aerosol retrieval from S5P/TROPOMI: new possibilities and expected performance
Authors: Litvinov Pavel , Dubovik Oleg , Chen Cheng , Lopatin Anton , Lapyonok Tatyana , Fuertes David , Bindreiter Lukas , Lanzinger Verena , Holter Christoph , Hangler Andreas , Aspetsberger Michael , de Graaf Martin , Tilstra Gijsbert , Stammes Piet , Retscher Christian
Published: March 2021

Sentinel-5p/TROPOMI instrument provides hyperspectral measurements in UV, VIS and infrared spectral range. Though the main purpose of the satellite is trace gases characterization, it is capable of aerosol and surface studies. In particular, S5p/TROPOMI measurements in UV provide unique information about absorption and elevation properties of aerosol. Moreover, measurements in wide spectral range are very sensitive to aerosol size and surface type.

In the framework of ESA S5P+I AOD/BRDF project an innovative algorithm for aerosol and surface retrieval from S5p/TROPOMI instrument is being developed. It integrates the advanced GRASP algorithm with the heritage AOD and DLER algorithm previously applied to TOMS, GOME(-2), SCIAMACHY and OMI sensors. The innovative algorithm is expected to provide surface BRDF and AOD with the accuracy required by most trace gas retrieval algorithms.

Here we present the results of aerosol and surface validation and inter-comparison obtained within ESA S5p+I project. New advanced possibility of aerosol and surface characterization from S5p/TROPOMI instrument will be discussed.
Slope instabilities in differently vegetated recent volcanic deposits
Authors: Cuomo Sabatino , Moscariello Mariagiovanna , Baumann Valerie , Bonadonna Costanza
Published: March 2021

Vegetation has an important role on slope stability and erosion through hydrological and mechanical processes. Especially plants transpiration and roots uptake can preserve a large amount of matric suction during and after a rainfall event. Soils properties as the water infiltration rate, the moisture content, the organic matter content and the aggregate stability are affected by plants cover as well. The presence of vegetation and its effect on soil moisture also implies an increase of shear strength. Moreover, plants roots increase the tensile strength and the overall shear strength of the vegetated soils, because of their ability to sustain tension, and to occupy the space of soil pores. Trees and shrubs roots produce significant cohesion-like aliquots of strength into shallow soil deposits and increase subsurface drainage, impacting the pronenesse of shallow landslides. Thus, vegetation acts on most of the soil properties which control the slope instability.

Volcanic eruptions can drastically change hillslope hydrology by removing or burying the vegetation in large areas. Events of rainfall-induced slope instability and erosion in differently vegetated recent volcanic deposits are here investigated using a distributed physically-based numerical model. The model considers the effect of vegetation through an additional amount of cohesion due to plants roots, the leaf area index, the average height of plants, the storage capacity of plant cover. Several sets of parameters are considered, and the effect of differently aged vegetation covers on the stability recent volcanic deposits stability is analysed.
Changes in Antarctic sea ice seasonality over the last 4 decades
Authors: Himmich Kenza , Vancoppenolle Martin , Madec Gurvan , Sallée Jean-Baptiste , Lebrun Marion
Published: March 2021

Changes in open water season duration in the Southern Ocean have been documented, with decreases in the Weddell and Ross sectors and increases west of the Antarctic Peninsula. Yet, not much is known on the mechanisms of changes. To progress understanding, we revisit Antarctic sea ice seasonality diagnostics (ice-free season duration, advance and retreat) from three satellite products. We diagnose their evolution at short and long time-scales, following the methodology of Lebrun et al (2019). We also put them in the context of oceanographic changes, as diagnosed from in situ observations. Preliminary analysis suggests that over the last decade, there was overall little change in the spatial distribution of the trends and of their magnitude, regardless of the used satellite product. Trends in all three diagnostics have slightly weakened but are still regionally significant. The ice-free season is still lengthening in the Bellingshausen and Amundsen Seas and shortening in the Weddell and Ross Seas. Where trends are significant, trends in ice advance date generally exceed those in ice retreat date. However, inter-annual variations in ice retreat date are larger than those in ice advance date. We will investigate possible reasons of this conundrum. We will also provide more analysis on possible links with water column stratification and surface energy budget. We hope such understanding will help us to better constrain the future evolution of Antarctic sea ice, and its impacts on marine biology and chemistry.
Effect of Plant Growth Promoting Rhizobacteria on Phytoextraction of Critical Raw Materials and Potentially Toxic Elements in Soil
Authors: Okoroafor Precious , Mann Lotte , Wiche Oliver
Published: March 2021

There are several regions of the world where soils are contaminated with potentially toxic elements (PTE) and/or have critical raw materials (CRM) that cannot be extracted through conventional raw material extraction techniques because of their low amounts. Phytoextraction- a kind of phytoremediation- offers good option or method to sustainably remediate these contaminated soils and extract these CRM from soils. The successful phytoextraction of these elements of interest from soil is dependent on their bioavailability for plant uptake and biomass production which could be increased by inoculating soil with plant growth promoting rhizobacteria (PGPR) and the element acquisition characteristics of the plant species used for phytoextraction. This study investigated the effect of the PGPR Bacillus amyloliquefaciens - FZB42 also called Rhizovital produced as spore’s formulation by ABiTEP on the phytoextraction efficiency of two selected species, Zea mays and Fagopyrum esculentum grown in potted soils under artificial lighting conditions for about 8 weeks in a laboratory. Results showed that for Fagopyrum esculentum, the inoculation of soil with Rhizovital increased the uptake of As, Cu, Pb and Co, Ni, Mg, K, P, La, Ce, Y, sum of Heavy Rare Earth Elements (HREE), sum of Light Rare Earth Elements (LREE) but significantly only for Cu and Co at alpha level 0.05 and insignificantly decreased the uptake for Ge. For Zea mays, results showed that inoculating soil with Rhizovital decreased uptake for all elements investigated and significantly so for only Co but showed an insignificant increasing effect on the uptake of Cu. For the two test species, similarity in effects of inoculation of soil with Rhizovital on uptake of elements only existed for Cu (increasing effect) and Ge (decreasing effect) suggesting that the addition of Rhizovital to soil could increase the Cu phytoextraction efficiency of Zea mays and Fagopyrum esculentum and decrease the phytoextraction efficiency of Germanium in both plants. Results from this research suggest that inoculation of soil with the PGPR Bacillus amyloliquefaciens - FZB42 could increase the phytoextraction of Copper by Zea mays and Fagopyrum esculentum respectively, thus enhancing the phytoextraction efficiency of both plants in soils contaminated by copper. Also, results suggest that inoculation of soil with Rhizovital could increase the phytoextraction efficiency of Fagopyrum esculentum for most of the PTEs and CRM investigated in this experiment and that Fagopyrum esculentum is a good candidate for PGPR assisted phytoextraction of PTE and CRM
Evolution of the debris-covered Miage Glacier
Authors: Stefaniak Anne , Robson Ben , Cook Simon , Clutterbuck Ben , Midgley Nicholas , Labadz Jillian
Published: March 2021

Glaciers in high-mountain regions typically exhibit a debris cover that moderates their response to climatic change. Here we present an integrated study that integrates long-term observations of debris-covered glacier mass balance, velocity, surface debris evolution and geomorphological changes (such as ponds and ice cliffs) of Miage Glacier, Italian Alps over the period 1952 – 2018. Analysis of the evolution of Miage Glacier highlighted a reduction in glacier activity associated with a period of sustained negative mass balance (-0.86 ± 0.27 metres per year water equivalent [m w.e. a-1]) and a substantial reduction in surface velocity (-46%). Ice mass loss of Miage Glacier was quantified using satellite imagery and derived digital elevation models (DEMs) applying the geodetic approach over a 28-year time period, 1990 – 2018. Temporal analysis highlighted an increase in surface lowering rates from 2012 – 2018. Further, the increase in debris-cover extent, supraglacial ponds and ice cliffs was evident since the 1990s. Supraglacial ponds and ice cliffs accounted for up to 8 times the magnitude of the average glacier surface lowering, whilst only covering 1.2 – 1.5% of the glacier area.

Ground-based photogrammetry and bathymetry surveys undertaken in 2017 and 2018 indicated the total volume of water storage at Miage Glacier increased by 46%, however, intermittent drainage events suggest this is highly variable over both seasonal and annual timescales. All ice cliffs underwent substantial vertical retreat upto a maximum rate of -8.15 ma-1 resulting in ice loss of 39,569 m3. Thus, ice loss from supraglacial ponds and ice cliffs are important to account for and have the potential to substantially impact future glacier evolution.
The causal link of large shallow slip, long duration and moderate shaking of the Nicaragua 1992 tsunami earthquake
Authors: Sallares Valenti , Prada Manel , Calahorrano Alcinoe , Meléndez Adrià , Ranero Cesar R. , Grevemeyer Ingo
Published: March 2021

Earthquakes rupturing up to close to subduction trenches have produced some of the largest tsunamis in history. Models indicate that the generation of these tsunamis require extraordinarily large near-trench sea-bottom displacement, but the underlying causes are disputed. They have been attributed to a wealth of factors prompting large shallow slip at the low-angle megathrust fault, the activation of steeper faults requiring smaller slip, or the triggering of ancillary energy sources. Although the postulated mechanisms are manifold, all of them coincide on the fact that the proposed causes and constraining factors are not universal but site-specific. As alternative to this local view, it has recently been proposed that the large near-trench slip could result from systematic upper-plate rock rigidity variations observed in worldwide subduction zones. Here we use a set of available controlled-source seismic data in the Middle America margin to obtain a model of upper-plate elastic rock properties across the rupture zone of the Ms7.0-Mw7.7 1992 Nicaragua tsunami earthquake. In combination with seismological data, our model shows that not only the required large shallow slip to generate the tsunami despite the moderate magnitude, but also the observed slow rupture propagation, long duration, high-frequency depletion, and magnitude discrepancy of this event, are all intrinsic physical attributes of near-trench rupture. The existence of a causal link between shallow slip and seismic record characteristics opens up new possibilities for tsunami early warning.
Numerical modelling assessment of glacier surge impact on observed elevation change signals
Authors: Vieli Andreas
Published: March 2021

Glacier surges periodically move ice masses to lower elevations and hence produce dynamic patterns of substantial thinning and thickening, but the net mass change over a typical time period of elevation change assessment of a few years to decades is not obvious.  Surging glaciers may therefore affect regional scale elevation change assessments as acquired from differencing of remotely sensed elevations, as for example for the observed Karakoram mass gain anomaly.

In this study I synthetically model glacier surges for a range of glacier sizes (slopes, thicknesses) and investigate the impact on the surface elevation change and total mass change for a typical range of surge durations, intensities and periods.

When keeping the climate forcing constant I find that the mean glacier elevation (or volume) is almost symmetric around the surge phase. Hence, when sampling elevation change over a large population of glaciers with randomly occurring surges there is little impact on the detected average elevation changes over all glaciers. The exceptions are steep glaciers which produce very short advance phases and much more extended phases of mass recovery. When sampling elevation change over a couple of years to decades, it is therefore much more likely to detect a thickening and therefore the population mean is biased to positive elevation change values.

When assessing mean elevation change on a regional scale, usually one fixed glacier outline is chosen for masking the data. However, for surging glaciers the extent can undergo large fluctuations. I therefore further assess the mean elevation change for glaciers extent masks that are varying between the maximum and minimum values of a surge. Despite a constant climate, the mean elevation change turns out to be increasingly biased towards detecting a thickening signal the further upstream the glacier extent is taken. This implies that for minimizing this thickening bias from glacier surges in assessing regional elevation change, glacier outline masks from their most extensive extents should be used.

Further modelling experiment showed that, the results are still valid when prescribing a variable climate forcing, but the surging effect is slightly subdued.  
Curating geosciences data in the Earth, Space and Environmental Sciences – new developments of GFZ Data Services
Authors: Ott Florian , Elger Kirsten , Ulbricht Damian
Published: March 2021

GFZ Data Services is a domain repository for geosciences data that assigns digital object identifier (DOI) to data and scientific software since 2004. Hosted at the GFZ German Research Centre for Geosciences (GFZ), the repository has a focus on the curation of long-tail data on one hand, but also provides DOI minting services for several global monitoring networks/observatories in geodesy and geophysics (e.g. INTERMAGNET; IAG Services ICGEM, IGETS, IGS; GEOFON) and collaborative projects (TERENO, EnMAP, GRACE, CHAMP). Furthermore, as Allocating Agent for IGSN, the globally unique persistent identifier for physical samples, GFZ is providing IGSN minting services for physical samples.

GFZ Data Services increases the interoperability of long-tail data through (1) the provision of comprehensive domain-specific data description via standardised and machine-readable metadata with controlled domain vocabularies; (2) complementing the metadata with comprehensive and standardised technical data descriptions or reports; and (3) by embedding the research data in wider context by providing cross-references through Persistent Identifiers (DOI, IGSN, ORCID, Fundref) to related research products (text, data, software) and people or institutions involved.

Visibility of the data is established through registration of the metadata at DataCite and the dissemination of metadata in standard protocols. The DOI Landing Pages embed metadata in Schema.org to facilitate discovery through internet search engines like the Google Dataset Search. In addition, we feed links of data and related research products into Scholix, which allows to link data publications and scholarly literature, even when the data are published years after the article.

The new Website of GFZ Data Services has further developed from a searchable data portal (only) to an information point for data publications and data management. This includes information on metadata, data formats, the data publication workflow, FAQ, links to different versions of our metadata editor and downloadable data description templates. Specific data publication guidance is complemented by more general information on data management, like a data management roadmap for PhD students, and links to the data catalogue of GFZ Data Services, the IGSN catalogue of GFZ and RI@GFZ – the data and research infrastructure search portal of GFZ.

Since October 2020, GFZ is a DataCite member. This membership will enable and promote active participation in the current and future venues of technological and service-oriented developments related to the persistent identification of research outputs.
The agricultural pressure cooker: how climate, demography, and value chain megatrends affect European rural regions
Authors: Debonne Niels
Published: March 2021

Rural regions in Europe are expected to deliver a range of contributions to the Sustainable Development Goals. However, these regions are under pressure by megatrends which shape their limitations and possibilities to contribute to sustainability now and in the future. Climate change demography, and value chain dynamics are three particularly interesting megatrends, because while they are global in scope, they have distinctly heterogeneous spatial signatures. The specific patterns and manifestations of climate and environmental change, demographic dynamics, and value chain constellations at the regional scale signal the expected agricultural change in that region, as well as the possibilities the region has to offer. Therefore, studying these megatrends can provide foresight into how European agriculture is likely to evolve. Farm upscaling can for example be expected in ageing regions which are well-embedded in global value chains and for which climate change impacts are either largely positive are not overly challenging to overcome. Other combinations of megatrends may lead to land abandonment, Californization (the use of migrant labor), or the development of sustainable markets. This research quantifies and maps megatrends, and identifies hotspots of megatrend interference. It discusses the implications of various combinations of megatrends, as they emerge across the European continent.
The Effective Temperature of Dust Impact Plasmas — Olivine Dust on Tungsten Target
Authors: Pavlů Jiří , Kočiščák Samuel , Fredriksen Åshild , DeLuca Michael , Sternovsky Zoltan
Published: March 2021

We experimentally observe both positive and negative charge carriers in impact plasma and estimate their effective temperatures. The measurements are carried on a dust accelerator using polypyrrole (PPy)-coated olivine dust particles impacting tungsten (W) target in the velocity range of 2–18 km/s. We measure the retained impact charge as a function of applied bias potential to the control grid. The temperatures are estimated from the data fit. The estimated effective temperatures of the positive ions are approximately 7 eV and seems to be independent of the impact speed. The negative charge carriers' temperatures vary from as low as 1 eV for the lowest speeds to almost ten times higher speeds. The presented values differ significantly from previous studies using Fe dust particles. Yet, the discrepancy can be attributed to a larger fraction of negative ions in the impact plasma that likely originates from the PPy coating.
Nitrogen loss in river and erosion banks in form of reactive dissolved nitrogen and nitrous oxide via microbial nitrification in permafrost-affected soils in the Lena Delta in the Siberian Arctic
Authors: Fiencke Claudia , Sanders Tina , Zell Nadine , Pfeiffer Eva-Maria , Beer Christian
Published: March 2021

Permafrost affected soils store a huge amount of organic matter including carbon and nitrogen. But especially permafrost is expected to degrade significantly through deepening and erosion processes with important consequences for freshwater systems. Although Arctic ecosystems are strongly limited by bioavailable nitrogen (N), the loss of vegetation by thermokarst and lack of vegetation on riverbanks probably establish conditions for imbalance in the nitrogen cycle, therefore higher N-availability for microbial transformations and in consequence loss of reactive nitrogen.

Here we present data from expeditions in 2008 and 2019, where we found indeed relatively high concentrations of dissolved inorganic nitrogen, mainly as ammonium (up to approx. 10 µg N g dw-1 ) in the active layer of dry no vegetated carbon poor mineral soils of the riverbank and cliff (recently eroded by the Lena river). In the stratified permafrost-affected soils of the riverbank nitrate accumulated during the summer period, especially in more organic silty layers (4 % SOM) to extremely high concentrations (up to approx. 90 µg N-nitrate g dw-1). Decreasing ammonium and increasing nitrate concentrations during the vegetation period hint to the aerobic nitrification process, which is the main source of nitrate in terrestrial ecosystem. Together with high nitrate concentrations in the field, these soil layers showed high potential nitrification rates in aerobic incubation experiments (max. 14.4 µg N g dw-1 d-1, 21,6 g N m-3 d-1, 5 °C) combined with high varying but significant N2O production rates (max. 150 µg N-N2O m-3 d-1, 5 °C). Since nitrification rates positively respond to temperature (max. Q10 of 4) and ammonium availability, climate change may cause an increasing release of gaseous N-loss (N2O) or leaching of nitrate and dissolved organic nitrogen (DON) to aquatic ecosystems with further consequences. Hot spots of high N-availability in no vegetated river and erosion banks likely influence the microbial induced C cycle as C-mineralization but also atmospheric methane oxidation, which might be the interest of future studies.