bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of drought vulnerability for maize in the eastern part of Northwest China
Authors: Wang Ying
Published: March 2020

Based on disaster theory, combined with the standardized precipitation index (SPI) and relative meteorological yield data, meteorological factors and social factors were comprehensively considered to assess the vulnerability of maize (Zea mays) to drought. The probability distribution curve for of the degree of meteorological drought and relative meteorological yield was obtained by using information distribution technology, using a two-dimensional normal information diffusion method to construct the vulnerability relationship between degree of meteorological drought and relative meteorological yield. This resulted in drought vulnerability curves for maize in the eastern part of Northwest China (Gansu, Ningxia, and Shaanxi), and calculations of drought risk for maize in each province. The probability of moderate drought in Shaanxi was relatively high, followed by Gansu and Ningxia. The probability distribution of Gansu was more discrete. The probability of strong meteorological drought in Ningxia was high, followed by Shaanxi and Gansu. Probability distribution of relative meteorological yield for maize in Gansu Province was highly discrete, with thick tailings, large uncertainties, and more extreme values, which were strongly affected by meteorological conditions, followed by Shaanxi and Ningxia. When the degree of meteorological drought was low, the relative meteorological yield of maize increased within 10%. This is because mild drought stress can promote the adaptability of maize to drought and stimulate maize’s overcompensatory effect. With an increased degree of meteorological drought, the relative meteorological yield of maize gradually declined. When the degree of meteorological drought exceeded –2.2, maize was most vulnerable to drought in Shaanxi followed by Ningxia and Gansu. When meteorological drought was < –2.2, maize was most vulnerable to drought in Shaanxi followed by Gansu and Ningxia. Shaanxi had the highest maize drought risk, followed by Gansu and Ningxia. This research had a clear physical background and clear risk connotations. The results provide a data foundation and a theoretical basis for drought prevention and disaster reduction for maize in the study area.
Temporal and spatial distributions of hourly rain intensity under the warm background in Xinjiang
Authors: chunyan Chen
Published: March 2020

It is well known that climate changes sometimes may cause natural disasters，especially the disastrous weather days，as downpour，flood，landslide and mudslide，and their derivatives disasters not only have relationship with precipitation，but also，closely with rainfall intensity. In the practice of Xinjiang disaster prevention，it’s urgent to know the temporal and spatial distributions of precipitation intensity and the maximum of precipitation intensity in different recurrence periods. In this paper，based on the observed hourly precipitation data over 16 national-standard stations during May to September from 1991 to 2013 in Xinjiang，some large-scale，multisites and long-paying observed hourly precipitation data have been used firstly together with the methods of probability distributions，statistical tests，variant difference analysis and extreme value analysis，the temporal and spatial distributions and the diurnal variation of hourly rain in summer in Xinjiang have been analyzed. The results show that the hourly rain presents high frequency in northwest and low frequency in southeast of Xinjiang. The high value center of the frequency with hourly rainfall intensity over 0.1 mm·h-1 or 4 mm·h-1 both in Western Tianshan Mountains. The frequency of heavy rainfall is increasing in places such as Ruoqiang where rains less. The high frequent periods of heavy rainfall，with hourly rainfall intensity over 4 mm·h-1，are often occurred in the afternoon，and the first and second half of the night in Northern Xinjiang，while it occurs at night in Southern Xinjiang. The hourly rain frequencies share obviously different diurnal variation in all regions of Xinjiang，where the hourly rainfall is not well-distributed. The distribution characteristic of daily rain in Northern Tacheng and Altay Prefecture is bimodal and in the rest regions of Northern Xinjiang is unimodal. Nevertheless，in Southern Xinjiang，most are in bimodal distribution. The total frequency of hourly rainfall intensity larger than 0.1 mm·h-1 or 4.0 mm·h-1 in Northern and Southern Xinjiang both appears to be an evident increase trend，and it would increase more significance in Southern Xinjiang in the 2010s. The high value region of hourly rainfall intensity occurring once in 50 or 100 years，respectively 45 mm·h-1 and 50 mm·h-1，both is in the western Aksu.
A new spatially distributed Added Value Index for Regional Climate Models: the EURO-CORDEX and the CORDEX-CORE highest resolution ensembles
Authors: Ciarlo` James M. , Coppola Erika , Fantini Adriano , Gao XueJie , Tong Yao , Glazer Russell H. , Torres Alavez Jose Abraham , Sines Taleena , Pichelli Emanuela , Raffaele Francesca , Das Sushant , Ashfaq Moetasim , Im Eun-Soon , Nguyen-Xuan Thanh , Teichmann Claas , Remedio Armelle , Remke Thomas , Bülow Katharina , Weber Torsten , Buntemeyer Lars , Sieck Kevin , Rechid Diana , Jacob Daniela
Published: March 2020

Regional Climate Models (RCMs) have undergone substantial development, resulting in increasingly reliable high-resolution simulations. Despite this, the added value of these simulations compared to their driving General Circulation Models (GCMs) has been a recurring issue. Past studies have used different techniques to quantify the added value of a RCM. A new method is now being presented, based on these past studies, that quantifies the added value and presents it spatially. The method was also adapted to assess the Downscaling Signal (DS) in climate change simulations and compare this to the added value.

This new method has been used to assess the daily precipitation of the 55-model EURO-CORDEX ensemble and the CORDEX-CORE ensemble, focusing especially on the higher-end of the PDFs. This revealed an overall positive added value across all domains, especially in areas of complex topography, cost-lines, and tropical regions. This DS was similar to that of the added value when looking at RCP 8.5 far-future simulations.
Harmonisation of a large-scale historical database with the principles of the World Reference Base for Soil Resources
Authors: Zádorová Tereza , Skála Jan , Penížek Vít , Žížala Daniel , Vaněk Aleš
Published: March 2020

The possibility of an adequate use of data and maps from historical soil surveys depends, to a large measure, on their harmonisation. Legacy data originating from a large-scale national mapping campaign, “Systematic soil survey of agricultural soils in Czechoslovakia (SSS, 1961–1971)”, were harmonised and converted according to the World Reference Base 2014 (WRB). Applying three different methods of taxonomic distance computation and quantitative analysis and reclassification of the selected soil properties, the conversion of so-called Basic soil representatives (BSR) – mapping soil units providing information about soil (type, subtype, variety) and lithology (parent material, texture, soil depth, skeleton content) – to their counterparts in the WRB has been effectuated. The results proved the good potential of the used methods for soil data harmonisation. The values of taxonomic distance correspond to the different concepts and settings of the soil classes in the harmonized soil classifications. Classes with specific and narrowly defined diagnostics, often with one or few strong and distinctive features, show close distances with their counterparts, and, often, have only one relevant counterpart. On the contrary, soils with variable soil properties were approximating several related units. The additional information on the soil skeleton content, texture, depth and parent material showed the potential in the specification of some units, though the harmonisation of the soil texture turned out to be problematic due to the different categorisation of soil particles. The resulting soil classes have been presented for each polygon (so-called soil district) as i) one to one conversion, when each BSR is converted to one, most probable, WRB soil class (Reference soil group, RSG) and ii) soil association corresponding to the three closest RSGs. The validation of the results in the study region showed an average overall accuracy for a one-to-one (59.4 %) conversion and a very good accuracy (83.8 %) for the polygons presented as soil associations. The conversion accuracy differed significantly in the individual soil units, and ranged from 92 % in Fluvizems to 0 % in Technosols and Histosols. The extreme cases of a complete mis-classification can be attributed to inconsistencies originating in the historical database and maps. The study showed the potential of modern quantitative methods in the legacy data harmonisation and also the necessity of a critical approach to historical databases and maps.

Supported by the Ministry of Agriculture of the Czech Republic, Project No. QK1820389.
The distribution of positive and negative turbulent heat diffusivity under urban pollution conditions
Authors: Zhang Zhe , Shi Yu , Sun Haijion , Liu Lei , Hu Fei
Published: March 2020

Turbulent diffusion efficiently transports momentum, heat, and matter and affects their transfers between the surface and the atmosphere. As an important parameter in describing turbulent diffusion, turbulent heat diffusivity KH has scarcely been studied in the context of frequent urban pollution in recent years. In this study, KH under urban pollution conditions was directly calculated based on the K-theory. We found an obvious diurnal variation in KH and its varying vertical distributions for each case and with time. Interestingly, the height of negative KH rises gradually after sunrise, peaks at noon, and falls near sunset. Negative KH is unusually significant at sunrise and sunset and approximately 140 m during most of the night. The magnitude and fluctuation in KH are smaller in the pollutant accumulation stage (CS) at all levels than in the pollutant transport stage (TS) and pollutant removal stage (RS). Turbulent diffusion may greatly affect PM2.5 concentration at the CS because of the negative correlation between PM2.5 concentration and the absolute value of KH at the CS accompanied by weak wind speed. The applicability of the K-theory is not very good during either day or at night. Note that these problems are inherent in K-theory when characterizing complex systems, such as turbulent diffusion, and require new frameworks or parameterization schemes. These findings may provide valuable insights for improving or establishing a new parameterization scheme for KH and promote the study of turbulent diffusion, air quality forecasting, and weather and climate modeling.
Changing exhumation potential of (U)HP eclogite through geological time
Authors: Palin Richard
Published: March 2020

Ultrahigh-pressure (UHP) metamorphism is defined by achieving P–T conditions sufficient to transform quartz to coesite (~26–28 kbar at ~500–900 °C), which occurs at ~90-100 km depth within the Earth under lithostatic conditions. Thus, the occurrence of UHP metamorphism is often taken as being a diagnostic indicator of subduction having operated in the geological record, and hence plate tectonics. Yet, the oldest such coesite-bearing rocks belong to the Pan-African belt in northern Mali, and formed at 620 Ma, although there exist multiple lines of evidence to show that a global network of subduction had been operative on Earth for billions of years beforehand. Why, then, are these key geodynamic indicators missing from the majority of the rock record? Here, I show how secular cooling of the Earth's mantle since the Mesoarchean (c. 3.2 Ga) has affected the exhumation potential of UHP (and HP) eclogite through time due to time-dependent compositional variation of both oceanic and continental crust. Petrological modeling of density changes during metamorphism of Archean, Proterozoic, and Phanerozoic composite continental terranes shows that more mafic Archean crust reaches a point-of-no-return during transport into the mantle at shallower depths than less MgO-rich modern-day crust, regardless of whether this occurs via subduction of stagnant lid-like vertical 'drip' tectonics. Thus, while Alpine- and Himalayan-type (U)HP orogenic eclogites represented by metamorphosed mafic intrusions into continental crust may readily have formed during the Precambrian, they would have lacked the buoyancy required for exhumation and preservation in the geological record.
Determining the position of the of thunder infrasound source using a large aperture micro barometer array
Authors: Rusz Jan , Chum Jaroslav , Baše Jiří
Published: March 2020

Large aperture array of absolute micro‑barometers located in Western Czechia was used to register distinct infrasound pulses generated by thunderstorm activity. Only cases with a sufficient signal-to-noise ratio on all four micro‑barometers were selected for further processing. Using data from the European lightning detection network and electric field monitor, a corresponding flash was assigned to each set of signals. The position of the infrasound source was calculated from the time delay of signal arrival, assuming propagation of spherical waves from the source. The calculation includes changes in sound speed as a function of temperature variation with altitude. Wind speed value and its variance is also taken into account to estimate the uncertainties. The calculated vertical positions of the infrasound sources are located at the altitudes between 3‑6 km. The horizontal position for most of the selected cases corresponds to the horizontal position of the flash specified by lightning detection network. The recorded infrasound signals followed only intracloud (IC) or mixed (multiple IC+CG) lightning strokes. Thus, the sources of the analyzed infrasound events are most likely IC discharges.
Estimation of River Discharge using Multi-Mission Satellite Altimetry and Optical Remote Sensing Imagery
Authors: Scherer Daniel , Schwatke Christian , Dettmering Denise
Published: March 2020

Despite increasing interest in monitoring the global water cycle, the availability of in-situ discharge time series is decreasing. However, this lack of ground data can be compensated by using remote sensing techniques to observe river discharge.

In this contribution, a new approach for estimating the discharge of large rivers by combining various long-term remote sensing data with physical flow equations is presented. For this purpose, water levels derived from multi-mission satellite altimetry and water surface extents extracted from optical satellite images are used, both provided by DGFI-TUM’s “Database of Hydrological Time series of Inland Waters” (DAHITI, https://dahiti.dgfi.tum.de). The datasets are combined by fitting a hypsometric curve in order to describe the stage-width relation, which is then used to derive the water level for each acquisition epoch of the long-term multi-spectral remote sensing missions. In this way, the chance of detecting water level extremes is increased and a bathymetry can be estimated from water surface extent observations. Below the minimum hypsometric water level, the river bed elevation is estimated using an empirical width-to-depth relationship in order to determine the final cross-sectional geometry. The required flow gradient is computed based on a linear adjustment of river surface slope using all altimetry-observed water level differences between synchronous measurements at various virtual stations along the river. The roughness coefficient is set based on geomorphological features quantified by adjustment factors. These are chosen using remote sensing data and a literature decision guide.

Within this study, all parameters are estimated purely based on remote sensing data, without using any ground data. In-situ data is only used for the validation of the method at the Lower Mississippi River. It shows that the presented approach yields best results for uniform and straight river sections. The resulting normalized root mean square error for those targets varies between 10% to 35% and is comparable with other studies.
Capturing flood risk dynamics with a coupled agent-based and hydraulic modelling framework
Authors: Michaelis Tamara , Brandimarte Luigia , Di Baldassarre Giuliano , Mazzoleni Maurizio
Published: March 2020

Floods are one of the costliest natural hazards worldwide, affecting millions of people every year. To plan flood risk reduction strategies, there is a need to understand how risk changes over time. In traditional flood risk assessment, vulnerability is often unrealistically considered constant in time, which does not reflect patterns observed in the real world. The coupled human and natural flood system is complex and determined by two-way interactions between the two subsystems. Floodplain dynamics may affect human behavior (e.g. by triggering the implementation of protection measures at different scales) which changes exposure and vulnerability, while they are also in turn influenced by human activities (e.g. land-use changes or flood protection structures). Here we explore how these two-way interactions influence changes in flood risk over time, with a focus on the role of individual and governmental decision-making, by developing a coupled agent-based and hydraulic modelling framework.

In our framework, household agents are located in a floodplain protected by a levee system. Individual behavior is based on Protection Motivation Theory and it comprises (as a response to floods) the options to do nothing, invest in private flood protection measures, or file a complaint to the government. The governmental decision making process about the implementation of technical flood protection measures, i.e. reinforcing the levee system, is a compromise between a Cost-Benefit-Analysis and relative number of filed complaints from the households. The agents take decisions at every time step of a long time series of annual maximum water levels: in case of levee breach, the floodplain water level is estimated by the LISFLOOD 2D hydraulic model, which is dynamically coupled into the agent-based model.

We show that this coupled model is capable of replicating adaptation and levee effects, which have been empirically observed by several scholars in numerous floodplains around the world. Thus, our framework provides a useful explanatory tool for assessing different spatial and temporal dynamics of flood risk in a socio-hydrological system. Moreover, the new modelling approach can explicitly simulate the spatial distribution of flood risk which allows for the analysis of conflicting interests in neighbouring communities. First, efforts have been made to include farmer agents into the model to simulate conflicts between urban and rural areas. Further, we exploit data from the real word in order to assess the credibility of our model and, lastly, use the model to investigate the effects of different climate scenarios on these types of conflicts.

 
Mentorship knows no distance: an online career mentorship programme by Women in Geospatial+
Authors: Szeto Sabrina H. , Wagemann Julia , Douglas Aubin A.
Published: March 2020

Women in Geospatial+ is a professional network that promotes gender-equality in the geospatial industry and academia. In October 2019, Women in Geospatial+ launched an online career mentorship programme that attracted over 180 global applicants. The inaugural cohort featured 42 participants from 17 countries who were matched with mentors, mentees or peer mentors based on their career goals and time zones. 

The programme enabled mentorship between mid-career and early career participants as well as peer mentorship between people with similar career stages. People of all genders were welcome to participate in this year-long programme. As a result, two men participated as mentors. Participants were provided with a mentorship programme guide with resources for a successful mentorship experience. They were also required to discuss goals and expectations as a group and submit an agreement form at the start of the programme. A safe space via a Slack channel was created where women could interact with other women participants in the mentorship programme. In addition, a social media campaign on Twitter and LinkedIn (#MentorshipMonday) also featured programme participants, their work and their achievements in the geospatial field.

This presentation will feature lessons learned from organising the mentorship programme as well as feedback from participants about how the mentorship programme has impacted their careers and professional growth.
How to disclose local equilibrium in subducted metapelites from the Cima Lunga Unit (Central Alps)
Authors: Piccoli Francesca , Lanari Pierre , Hermann Jörg , Pettke Thomas
Published: March 2020

Subducted metapelites are more prone to re-equilibrate during exhumation than mafic or ultramafic rocks to the point that recognizing high-pressure (HP) relicts is often very challenging. Geologic evidence from the Cima Lunga Unit (Central Alps) show this apparent discrepancy between high to ultra-high pressure metamorphism (28 kbar and 780 °C) recorded in mafic/ultramafic lenses, and Barrovian metamorphism (<10 kbar, 650°C) in the adjacent metapelitic rocks. We collected a white mica – garnet – biotite – plagioclase – kyanite (+ quartz, + zircon, + rutile) bearing metapelite adjacent to the garnet metaperidotite lens that displays an apparently well equilibrated Barrovian mineral assemblage (garnet + plagioclase + biotite), with no macroscopic or microtextural indication of a HP and/or HT metamorphic event (e.g. omphacite crystals; migmatitic texture; polyphase inclusions). Nevertheless, microstructures like atoll-like garnet or large white mica flakes surrounded by biotite and ilmenite replacing rutile suggest incomplete re-equilibration. We investigated garnet and phengite crystals by electron probe and laser ablation-ICP-MS mapping. Major and trace element mapping reveals very complex mineral zoning in both minerals. In particular, high Ti content in phengite and increasing P and Zr contents in pyrope-rich garnet indicate that the studied rock underwent a HP-HT event. This is also supported by Zr in rutile thermometry that indicates temperatures well above the Barrovian metamorphism (T > 700 °C). We combined detailed textural analysis with petrological-geochemical data and thermodynamic modelling to reconstruct the metamorphic evolution of the studied rock. We show that, thank to incomplete re-equilibration, the rock documents an evolution from prograde to UHP-HT peak (27 kbar and 800 °C) to retrograde (Barrovian) conditions (10 kbar and 620 °C). Noteworthy, peak metamorphic conditions of metapelite coincide with peak metamorphic conditions of the garnet metaperidotite. Lastly, geochemical evidence for minor wet melting of the studied metapelite at HP-HT conditions was recognized and is likely linked to the dehydration of chlorite to form garnet peridotite in the adjacent ultramafic body. We propose that metapelites and ultramafic rocks were coupled before subduction or at least in its early stage. This finding opens new scenarios for the geodynamic interpretation of the Cima Lunga unit. We propose that the ultramafic lenses at Cima di Gagnone were parts of the exhumed and serpentinised mantle emplaced at the hyper-extended European continental margin of the Piemont-Ligurian ocean. Slices of the margin were detached and tectonically mixed in the subduction channel. These new constraints call for re-evaluation of the paleogeographic position of the Adula-Cima Lunga nappe.
Measuring plant hydraulic conductance and xylem vulnerability under close to natural conditions
Authors: Krieger Louis , Schymanski Stanislaus
Published: March 2020

Usually hydraulic conductance and vulnerability are measured under extreme conditions never experienced by living plants (e. g. centrifugation, bench dehydration, and large pressure gradients). A common factor that is known to inhibit the water transport in plants is cavitation, which is believed to occur either by air entry through the pit valves on the walls of the xylem, or by ex-solution of dissolved gases, or vaporization of water at very low pressures. Various physical characteristics of the xylem influence the efficiency of transport and the vulnerability to cavitation.

Here we explore possibilities to measure hydraulic conductance and induce cavitation under close to natural conditions. We designed a very simple “artificial plant” consisting of a root and a transpiring membrane, equipped with pressure and flow meters, where a twig can be inserted in the flow path to measure its hydraulic conductance. Attempts to induce cavitation resulted in surprising results, provoking new questions on the role of xylem structural traits and their relevance for water transport in plants.
Midas or Gaia revisited, about anthropogenic tempering with the natural response system
Authors: Waveren Isabel
Published: March 2020

The controversy between the CO2 driving or lagging models is elucidated in a new climate model, that reunites insights from models from other planets, carbon draw down models during earth history as a whole, spores spike related to catastrophic events from the Phanerozoic, late Palaeozoic climate models and carbon dioxide and temperature fluctuations during the Quaternary as shown by Petit et al., (1999).

 

This model advocates that for the natural system orbitally induced insolation maxima (eccentricity in particular) momentarily and erratically trigger ocean degassing and drive temperature rise orbitally while it is otherwise driven by carbon drawdown through photosynthesis leading to cooling.

 

For the natural system high concentrations of particulate organic carbon (fungal spore, pollen, vegetation debris, soot and charcoal) or abiotic dust are forming crystallisation cores that trigger an ephemeral greenhouse effect in the cirrus from the lowermost stratosphere. This happens at the onset of orbital insolation peaks when warming leads to larger crystal sizes. The consecutive warming induces the waxing of the cirrus forming sphere which necessarily has lower concentrations of crystallisation cores and shifts back to the albedo effect.

 

In this model the decrease in CO2 concentration in the atmosphere through photosynthesis regulates temperature and supports the view that temperature lags CO2 concentration, yet in this natural system, the greenhouse effect is briefly triggered by orbital forcing and support the results of Feulner (2017) indicating that both the carbon drawdown and orbital forcing are driving temperature in the natural system. In this model the CO2 gets ping-ponged from the terrestrial to the marine system until both are depleted in CO2.  It indicates that, ultimately, under natural circumstances, spreading rate and tectonic events drive climate. From this model it also follows that the industrial use of organic and inorganic carbon sinks, as they have constantly been replenished during earth history through tectonic activity, will lead to CO2 concentrations as experienced before photosynthesis appeared and concentrations far beyond.

 

The aberrant CO2 and temperature rise in the Anthropocene reflects the tempering of the response system in the lowermost stratosphere because of increasing concentrations of particulate organic carbon and dust by changing land use, lowering of the ground water table by wood cutting, aridification (pyro-cumulonimbi), transport (contrails) and soot emission.
Droughts, heatwaves, and wildfires: exploring compound and cascading events of dry hazards at the pan-European scale
Authors: Sutanto Samuel Jonson , Vitolo Claudia , Di Napoli Claudia , D'Andrea Mirko , Van Lanen Henny
Published: March 2020

Compound and cascading natural hazards usually cause more severe impacts than any of the single hazard events alone. Despite the significant impacts of compound hazards, many studies have only focused on single hazards. The aim of this paper is to investigate spatio-temporal patterns of compound and cascading hazards using historical data for dry hazards, namely heatwaves, droughts, and fires across Europe. We streamlined a simple methodology to explore the occurrence of such events on a daily basis. Droughts in soil moisture were analyzed using time series of a threshold-based index, obtained from the LISFLOOD hydrological model forced with observations. Heatwave and fire events were analyzed using the ERA5-based temperature and Fire Weather Index datasets. The data used in this study relates to the summer seasons from 1990 to 2018. Our results show that joint dry hazard occurrences were identified in west, central, and east Europe, and with a lower frequency in southern Europe and eastern Scandinavia. Drought plays a substantial role in the occurrence of the compound and cascading events of dry hazards, especially in southern Europe as it drives the duration of cascading events. Moreover, drought is the most frequent hazard-precursor in cascading events, followed by compound drought-fire events. Changing the definition of a cascading dry hazard by increasing the number of days without a hazard from 1 to 21 within the event (inter-event criterion), lowers as expected, the maximum number of cascading events from 94 to 42, and extends the maximum average duration of cascading events from 38 to 86 days. We had to use proxy observed data to determine the three selected dry hazards because long time series of reported dry hazards do not exist. A complete and specific database with reported hazards is a prerequisite to obtain a more comprehensive insight into compound and cascading dry hazards.
Ion cloud expansion after hypervelocity dust impacts detected by the MMS spacecraft
Authors: Vaverka Jakub , Pavlů Jiří , Nouzák Libor , Kočiščák Samuel , Šafránková Jana , Němeček Zdeněk
Published: March 2020

Dust grains impacting with high velocities the spacecraft body can be partly or totally evaporated and create clouds of charged particles. Presence of electrons and ions generated by such hypervelocity impacts can consequently influence the spacecraft potential and/or measurements of on-board scientific instruments. Electric field instruments are able to register signals generated by dust impacts as short pulses in the measured electric field. These signals can be used for detection of dust grains by the spacecraft without dedicated dust detectors. This dust detection method has been successfully used for data collected by many spacecraft as Voyager, Cassini, Wind, STEREO, MAVEN, and MMS. On the other hand, our understanding of this complex process comprising from dust grain evaporation, generation of charged particles, to impact cloud expansion and signal detection is still not complete.

We present a study of events related to dust impacts on the spacecraft body detected by electric field probes operating simultaneously in the monopole (probe-to-spacecraft potential measurement) and dipole (probe-to-probe potential measurement) configurations by the Earth-orbiting MMS spacecraft. The presented study is focused on events when expanding ions affect not only the potential of the spacecraft body but also one or more electric probes on the end of antenna booms. Expanding ions can influence electric probes located far from the spacecraft body only when the spacecraft is located in tenuous ambient plasma as inside of the Earth’s magnetosphere. This analysis can confirm if these events are really connected to dust impacts and gives us some information about ion expansion velocity, and improve our knowledge of dust impact process.
On monsoon character of circulation over the Barents and Kara Seas
Authors: Kislov Alexander , Matveeva Tatiana
Published: March 2020

This study analysed the monsoon features of atmospheric circulation in the Barents and Kara Seas, the variability of atmospheric circulation, and anomalies in temperature, precipitation, and wind speed. In a cold period, the extreme winds are southerly winds that develop in the eastern parts of cyclones. In the warm season, the extreme speeds correspond to a northerly wind in the western periphery of cyclones. The regional circulation systems were divided into ten circulation weather types, separately for each sea. Their frequencies were compared with different indexes, describing the main modes of variability for the arctic region (the North Atlantic Oscillation, the summer North Atlantic Oscillation, the Scandinavia teleconnection pattern, the Siberian High). In the winter season, the monsoon currents from land to sea occur only when the North Atlantic Oscillation index is positive. With the prevalence of other modes of variability, the direction of the winds can be different, and this causes the monsoon regularity to be stochastic. In summer, the northern streams move on the western periphery of cyclones, regenerating and stabilizing over the Kara Sea.

The work was supported by the grant of the Russian Foundation for Basic Research (RFBR) [project number 18-05-60147] and this work was carried out as part of governmental assignment АААА-А16-116032810086-4.
Late Pleistocene-Holocene tectonic asymmetry of the Lena Delta
Authors: Aksenov Aleksei , Bolshiyanov Dmitriy , Makarov Aleksandr , Pravkin Sergei , Lazareva Elena , Cherezova Anna , Grigoriev Mikhail
Published: March 2020

The Lena Delta is the largest arctic delta in the world (about 29000 km2). Unlike other deltas, its formation was the result of both erosion and accumulation during Late Pleistocene and Holocene. It was caused by combination of continuous sea-level fluctuations and neotectonic movements. The last ones have different speed and direction. From previous studies it is known that western part of delta has uprising tectonic movements while the eastern one is sinking. This asymmetry develops along the fracture extended submeridially across the delta. The aim of this research is to measure the amplitude and speed of these movements by using geomorphologic methods. For that purpose results of German-Russian expedition “Lena” were used. In 2013, 2014, 2015 surface morphology of the biggest delta’s islands Sobo-Sise, Kurungnakh, Jangylakh-Sis and Khardang-Sise located in both eastern and western parts was investigated with high-quality sattelite instruments. These islands consist of the Late Pleistocene Ice Complex (IC) remnants with altitude 20-66 m above sea-level (a.s.l.), eroded by river and sea, and the first accumulative terrace of the delta with 2-15 m a.s.l. IC remnants accumulated in the Late Pleistocene 50-17 ka cal BP. The first terrace was forming in Holocene from 8 ka cal BP to 2 ka cal BP. So, there were made a number of geomorphologic profiles with use of high-quality satellite instruments across river terrace and IC remnants during the expeditions. In this study, we equated them to one level and compared. With use of radiocarbon age and digital elevation models (DEM) data we compared heights and age of islands in eastern and western parts and estimated neotectonic movements’ speed difference. Since 2000 years BP tectonic asymmetry represented in terrace surfaces has been increasing with rate about 2 mm per year. Before 2000 cal BP speed difference approximately values 1 mm per year. Our data correlates with water-flow measurements in the delta, modern water-level observations in Laptev Sea and geophysical investigations.
The Present and Future Role for sUAS in Atmospheric Sciences
Authors: Baker Bruce , Dumas Ed , Lee Temple , Buban Michael
Published: March 2020

The scientific community is beginning to see how our environment reacts to changes on an unprecedented time and space scale with the utilization of small Unmanned Aircraft Systems or sUAS.  These new observation platforms can be utilized for flood forecasting, local weather forecasting, monitor wildlife, improve hurricane forecasts and this the tip of the iceberg. This technology is a new tool that will allow the scientific community to observe the environment on time and space scales that are unprecedented.  This particular talk will primarily address the future of these observing platforms as it relates to advancing the atmospheric sciences. UAS’s are rapidly becoming the new technology that can acquire low-level environment information more frequently, in support of higher-resolution model forecasts of severe thunderstorm and tornado potential, improvement in  Environmental Model Prediction, provide environmental  information to provide better support  the spread of wildfires and smoke, as well as wildfire imagery for Incident Command and more complete/accurate storm damage surveys.  One of the end goals would be to have  a nationwide network of sUAS providing near-continuous observations of thermodynamic parameters, NDVI, surface sensible heat and wind speed and direction. Most of these observations are being done on a regular basis and some will be attainable in the future as technology progresses and National Airspace becomes more accessible. 
A 3-D Model of Antarctic Ice Shelf Surface Hydrology
Authors: Buzzard Sammie , Robel Alex
Published: March 2020

Understanding the surface hydrology of ice shelves is an essential first step to reliably project future sea level rise from ice sheet melt. The formation of surface meltwater has been linked with the disintegration of many ice shelves in the Antarctic Peninsula over the last several decades. The most notable ice shelf collapse occurred in 2002 when significant meltwater lake coverage was observed on the surface of the Larsen B Ice Shelf before its collapse over a period of just a few weeks. Such collapse can affect ocean circulation and temperature, and cause a loss of habitat. Additionally, it can cause a loss of the buttressing effect that ice shelves can have on their tributary glaciers, thus allowing the glaciers to accelerate, contributing to sea level rise. Despite the importance of surface meltwater production and transport to ice shelf stability, knowledge of these processes is still lacking and as a result of this, projections of future sea level rise still vary over an order of magnitude.

 

In order to better understand these processes we present a new 3-D model of surface hydrology for Antarctic ice shelves. This model takes the 1-D surface lake formation model of Buzzard et al. (2018) and expands it to three dimensions. It is the first comprehensive model of surface hydrology to be developed for Antarctic ice shelves, enabling us to incorporate key processes such as the lateral transport of surface meltwater. Recent observations suggest that surface hydrology processes on ice shelves are more complex than previously thought, and that processes such as lateral routing of meltwater across ice shelves, ice shelf flexure and surface debris all play a role in the location and influence of meltwater. Our model allows us to account for these as well as additional key physical processes and is calibrated and validated through both remote sensing and field observations.

 

Here we present results of coupling the 1-D model with a 3-D meltwater routing scheme. This includes calculations of the surface energy balance, meltwater production, percolation and refreezing and lake formation. Through case studies, calibrated and validated against observations, we will demonstrate the varied applications of the model.

 

This community-driven, open-access model, has been developed with input from observations, and allows us to provide new insights into surface meltwater distribution on Antarctica’s ice shelves. This enables us to answer key questions about their past and future evolution under changing atmospheric conditions and vulnerability to meltwater driven hydrofracture and collapse.

 
A coupled watershed-biogeochemical model to simulate dissolved and particulate 137Cs discharge from a forested catchment affected by the Fukushima accident
Authors: Sakuma Kazuyuki , Yoshimura Kazuya , Kurikami Hiroshi , Malins Alex , Funaki Hironori
Published: March 2020

Dissolved 137Cs discharge represents approximately 30% of the total 137Cs discharge from the forested upstream catchment of the Ohta River in Fukushima, Japan [1]. It is thought that a major source of the dissolved 137Cs entering the river water may be leaching from forest litter [1]. A watershed simulation based on the distribution coefficient (Kd) that modelled water, sediment, and particulate and dissolved 137Cs transport could not reproduce the seasonal variability of the base flow dissolved 137Cs concentrations, nor the peaks in concentration that occurred during storms [2].

We developed a combined watershed-biogeochemistry model for simulating dissolved and particulate 137Cs discharge from forest catchments to describe the two phenomenon as mentioned above. A compartment model for the forest ecosystem was appended to the General-purpose Terrestrial fluid-Flow Simulator (GETFLOWS) watershed code. The compartment model included compartments for undecomposed and decomposed litter, with transfer from the former into the latter depending on temperature. A pathway for dissolved 137Cs input to forest streams was linked from the decomposed litter compartment.

The results from a simulation with the new simulation model reproduced the seasonal variability of dissolved 137Cs concentrations and the peaks occurring during storms. Therefore the new modelling results add weight to the theory that leaching from decomposed litter can input dissolved 137Cs concentrations in river water in Fukushima Prefecture. The developed model is expected to be useful for further explorations into factors affecting dissolved 137Cs input to river water in forested catchments.

 

[1]Tsuji et al., 2016. J. Geophys. Res. Biogeosci. 121, 2588-2599.

[2]Sakuma et al., 2018. J. Environ. Radioact. 184-185, 53-62.
qConut: A mobile geospatial application for promoting sustainable and climate-smart Pacific Island agricultural landscapes
Authors: Biggs Eloise , Boruff Bryan , Boyland Michael , Bruce Eleanor , Davies Kevin , Duncan John , Grünbühel Clemens , Manu Viliami , Mateboto Jalesi , Myat Thu Pyone , Neef Andreas , Oakeshott John , Pauli Natasha , Shojaei Helena , Varea Renata , Wales Nathan
Published: March 2020

Successful ‘smart’ agricultural interventions provide mutually positive impacts to inhabitants’ livelihoods, landscape sustainability, and the capacity of a system to respond effectively to climate variability. Geospatial technological tools have the potential for accurate and timely locational monitoring within multifunctional landscapes. Information derived from using such tools can substantially inform environmental management, policy, and climate-resilient practice. Our research is developing a mobile geospatial application for contemporary data collection and monitoring, allowing the dynamic capture of landscape information. Through community consultations, stakeholder engagement activities, and Information and Communications Technologies for Development (ICT4D) user requirements analysis, we have mapped government data flows and information needs of smallholder farmers in the Pacific Island nations of Fiji and Tonga. Subsequently, the barriers experienced by landscape users to access and understand relevant, reliable and usable environmental data and information were identified. We then designed an open-source mobile geospatial application to facilitate knowledge sharing between different landscape stakeholders. Our multi-user open source application – qConut – is being co-developed with the Ministry of Forests in Fiji and the Ministry of Agriculture, Food and Forests in Tonga, alongside collaborative participatory contributions from the wider farming communities. Here we present the methodological approach, application functionality, and prototype usability outcomes from field testing undertaken in the Ba Catchment, Fiji, and Tongatapu, Tonga. The qConut application has a current target user focus on agricultural extension officers who are trialling the application within cropping and forestry sectors. Results of trial usage highlight the importance of understanding the specific needs and capacities of all stakeholder groups in developing effective digitally-enabled climate information services. By utilising mobile geospatial technologies our research is helping to address shortcomings in location-targeted information delivery, environmental monitoring, and data sharing within Pacific Island agricultural communities. See www.livelihoodsandlandscapes.com for further information.
Huge Landslides along the Jinsha River in Southeastern Tibetan Plateau and Their Association with the Recent Activity of Jinsha River Fault Zone
Authors: Chang Zufeng , Chang Hao , Mao Zebin , Guo Ruojin
Published: March 2020

     The Jinsha river fault zone in the eastern margin of the Tibetan Plateau is an old suture structure after the shutting of the proto-Tethys and a large scale ultra-lithosphere fault zone consisted of  5 to 6 fault branches with a width of 50km, have a long  geological evolution history. Since late Quatery, this fault zone is mainly dominated by dextral strike slip with partial thrusting component, absorbing  partial energy of the extrusion movement of  Tibetan Plateau. Along the fault zone, lower terraces of Jinsha river at Muronglou, Buzhong, Langzhong, Guxue, etc. were displaced, indicating the fault zone is active in late Quaternary, with an average rate of 3.5～4.3mm/ /yr. horizontally and 0.9-1.1mm/yr. vertically respectively in Holocene. Influenced by the intense fault activity of Jinsha river fault zone, this region is characterized by fractured rocks, strongly weathered surfaces.

      The Jinsha river, the upstream of the Yangtze river, parallel to Jinshajiang fault zone, flows from north to south, forming deep river valley and huge terrain elevation difference. Numerous huge landslides have developed along the river, for example, there are 23 giant avalanches in the 38 km long reach from Narong to Rongxue, with general volumes of 10~70 million m3 and even up to several hundreds million m3. Moreover, the landslides produce many loose clastic fragments which detonate many debris flows and river blocking. The latest disaster event is the Baige barrier lake in 2018 caused by landslide, with a water storage capacity of 524 million m3, causing tens of billions of yuan of economic losses. These landslides are distributed along the fault and its two sides, suggesting that these huge avalanches are closely related to the intense activity of the fault zone and special topography.

Keywords: Huge landslide, Jinsha River, Jinsha River Fault Zone, late Quatery activity