bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Global Synthetic Tropical Cyclone Hazard Probabilities using the STORM dataset
Authors: Bloemendaal Nadia , Haigh Ivan , de Moel Hans , Muis Sanne , Aerts Jeroen
Published: March 2020

Tropical cyclones (TCs), also referred to as hurricanes or typhoons, are amongst the deadliest and costliest natural disasters, affecting people, economies and the environment in coastal areas around the globe when they make landfall. In 2017, Hurricanes Harvey, Irma and Maria entered the top-5 costliest Atlantic hurricanes ever recorded, with combined losses estimated at $220 billion. Therefore, to minimize future loss of life and property and to aid risk mitigation efforts, it is crucial to perform accurate TC risk assessments in low-lying coastal regions. Calculating TC risk at a global scale, however, has proven to be difficult, given the limited temporal and spatial information on landfalling TCs around much of the global coastline.

In this research, we present a novel approach to calculate TC risk under present and future climate conditions on a global scale, using the newly developed Synthetic Tropical cyclOne geneRation Model (STORM). For this, we extract 38 years of historical data from the International Best-Track Archive for Climate Stewardship (IBTrACS). This dataset is used as input for the STORM algorithm to statistically extend this dataset from 38 years to 10,000 years of TC activity. Validation shows that the STORM dataset preserves the TC statistics as found on the original IBTrACS dataset. The STORM dataset is then used to calculate global-scale return periods of TC-induced wind speeds at 0.1°resolution. This return period dataset can then be used to assess the low probabilities of extreme events all around the globe. Moreover, we demonstrate the application of this dataset for TC risk modeling on small islands in e.g. the Caribbean or in the South Pacific Ocean.
Understanding Long-Term Changes of Coastal Saltmarshes from Satellite Remote Sensing
Authors: Laengner Marieke , van der Wal Daphne
Published: March 2020

Saltmarshes are known to be very important coastal ecosystems. They provide crucial functions for flora and fauna, as well as valuable ecosystem services for humankind. Many methods that are used to investigate these ecosystems are limited in space and time. Long time series of global satellite data enable to observe changes in the extent of saltmarshes on a large scale and over a long time period. We developed an unsupervised decision tree classification method in Google Earth Engine that automatically classifies satellite images into saltmarsh vegetation, mudflats, and open water. We applied the method using Landsat 5 TM data between 1985 and 2011. With this, we are able to detect trends in the seaward extent of saltmarshes globally. We reveal transitions between saltmarsh, mudflat and open water. Furthermore, we put saltmarsh habitat changes in a spatial context and couple trends in saltmarsh dynamics to environmental drivers, such as sea level rise, tidal forces, waves, and sediment availability.
Sulfur cycling in carbonatite of the Kaiserstuhl volcanic complex (Germany)
Authors: Kuhn Bianca , Peters Christian , Schurr Simon
Published: March 2020

The redox sensitive element sulfur is used for reconstructing the oxygen fugacity during magmatic melt evolution applying the sulfur isotopic composition of sulfide and sulfate minerals. Especially fast ascending sulfur-rich alkaline magma from the upper mantle provides the possibility for determining the oxidation state of Earth`s mantle via a detailed investigation of the sulfur cycling. Here we present the first sulfur isotope data of sulfides, sulfates as well as carbonate associated sulfate (CAS) of carbonatite (sövite) from two well-studied locations (Orberg and Badberg) of the Kaiserstuhl volcanic complex, situated in the southern part of the Upper Rhine Graben (Germany). Based on our results, sövites are 25000 times more enriched in sulfate than in sulfide. Sulfides display a δ34S value of 0.6 ‰ (V-CDT), whereas water-soluble sulfate (e.g. anhydrite) show a sulfur isotopic composition between 3.8 ‰ and 6.1 ‰. δ34SCAS data are at 6 ‰ at the Orberg and 9 ‰ at Badberg locality. Our sulfur isotope data are comparable to other carbonatite occurrences worldwide (e.g. Phalabora, South Africa), emplaced at similar temperatures (ca. 860 °C). However, the strongly elevated sulfate content recorded here for sövites formed at this high temperature is unique and indicates an enhanced oxidation state during sövite formation in the Kaiserstuhl volcanic complex.
Remember the past: A comparison of time-adaptive training schemes for non-homogeneous regression
Authors: Lang Moritz N. , Lerch Sebastian , Mayr Georg J. , Simon Thorsten , Stauffer Reto , Zeileis Achim
Published: March 2020

Non-homogeneous regression is a frequently-used post-processing method for increasing the predictive skill of probabilistic ensemble weather forecasts. To adjust for seasonally varying error characteristics between ensemble forecasts and corresponding observations, different time-adaptive training schemes, including the classical sliding training window, have been developed for non-homogeneous regression. This study compares three such training approaches with the sliding-window approach for the application of post-processing near-surface air temperature forecasts across Central Europe. The predictive performance is evaluated conditional on three different groups of stations located in plains, in mountain foreland, and within mountainous terrain, as well as on a specific change in the ensemble forecast system of the European Centre for Medium-Range Weather Forecasts (ECMWF) used as input for the post-processing.

The results show that time-adaptive training schemes using data over multiple years stabilize the temporal evolution of the coefficient estimates, yielding an increased predictive performance for all station types tested compared to the classical sliding-window approach based on the most recent days only. While this may not be surprising under fully stable model conditions, it is shown that "remembering the past" from multiple years of training data is typically also superior to the classical sliding-window when the ensemble prediction system is affected by certain model changes. Thus, reducing the variance of the non-homogeneous regression estimates due to increased training data appears to be more important than reducing its bias by adapting rapidly to the most current training data only.
An analytical model for multispecies reactive transport through a heterogeneous formation consisting multiple layers of differing physical and chemical properties
Authors: Chen Jui-Sheng , Liang Ching-Ping , Chang Cheng-Hung
Published: March 2020

Transport behaviors of contaminants through a heterogeneous formation consisting multiple layers are complicated because of the different physical and chemical properties for each individual layer. Few analytical solutions for single-species contaminant transport in a multi-layer heterogeneous formation have been reported in the literature. Some contaminants of concern such as radionuclide, nitrogen and chlorinated solvents can decay or degrade to form new successor products during their transport processes, thus making migration of these contaminants much complicated. Clearly, analytical models for multispecies transport coupled by a series of decay reactions in a multi-layer formation are useful tools for synchronous determination of the fate and transport of the predecessor and successor species of decaying or degradable contaminants. This study attempts to develop an analytical model for the multispecies reactive transport of degradable or decaying contaminants through a multi-layer heterogeneous formation. The derived analytical model is shown to be correct and accurate as the consistent results of comparisons between the derived analytical model and the numerical model. The developed analytical model will provide a more reliable predicting tool for real world application.

 
Risk management and risk assignment: from digital distruption to statistical tools for natural events’ Risk
Authors: Di Trapani Giovanni , Somma Renato , Coviello Antonio , De Natale Giuseppe , Troise Claudia , Trocciola Alfredo
Published: March 2020

Recent calamities in Italy caused by natural disasters encouraged scientists and politicians to assess the need to find instruments for limiting risks. Risk Management suggests methods of adopting various options. A successful approach, thanks to the inexorable growth of digital technology, involves the use of the information infers from the decoding of Big Data. The radical technological advances generated by digital technologies require the application of appropriate statistical tools. The adoption of more flexible and interactive tools and strategies to analyses the natural phenomena (e.g. floods and landslides) as well as possible disasters like eruptions and earthquakes could ensure an optimal response to risk transfer and management.
Global and regional performances of SPI candidate distribution functions in observations and simulations
Authors: Pieper Patrick , Düsterhus André , Baehr Johanna
Published: March 2020

The Standardized Precipitation Index (SPI) is a widely accepted drought index. Its calculation algorithm normalizes the index via a distribution function. Which distribution function to use is still disputed within literature. This study illuminates the long-standing dispute and proposes a solution which ensures the normality of the index for all common accumulation periods in observations and simulations.

We compare the normality of SPI time-series derived with the gamma, Weibull, generalized gamma, and the exponentiated Weibull distribution. Our normality comparison evaluates actual against theoretical occurrence probabilities of SPI categories, and the quality of the fit of candidate distribution functions against their complexity with Akaike's Information Criterion. SPI time-series, spanning 1983–2013, are calculated from Global Precipitation Climatology Project's monthly precipitation data-set and seasonal precipitation hindcasts from the Max Planck Institute Earth System Model. We evaluate these SPI time-series over the global land area and for each continent individually during winter and summer. While focusing on an accumulation period of 3-months, we additionally test the drawn conclusions for other common accumulation periods (1-, 6-, 9-, and 12-months).

Our results suggest to exercise caution when using the gamma distribution to calculate SPI; especially in simulations or their evaluation. Further, our analysis shows a distinctly improved normality for SPI time-series derived with the exponentiated Weibull distribution relative to other distributions. The use of the exponentiated Weibull distribution maximizes the normality of SPI time-series in observations and simulations both individual as well as concurrent. Its use further maximizes the normality of SPI time-series over each continent and for every investigated accumulation period. We, therefore, advocate to derive SPI with the exponentiated Weibull distribution, irrespective of the heritage of the precipitation data or the length of analyzed accumulation periods.
Decadal Predictions of the Probability of Occurrence for Summer Temperature Extremes in the Northern Hemisphere
Authors: Borchert Leonard , Pohlmann Holger , Baehr Johanna , Neddermann Nele-Charlotte , Suarez Gutierrez Laura , Müller Wolfgang A.
Published: March 2020

We use a decadal prediction system with the Coupled Model Intercomparison Project Phase 6 version of the coupled Max Planck Institute Earth System Model to predict the probability of occurrence for extremely warm summers in the Northern Hemisphere. An assimilation run with Max Planck Institute Earth System Model shows a robust response of summer temperature extremes in northern Europe and northeast Asia to North Atlantic sea surface temperature via a circumglobal Rossby wavetrain. When the North Atlantic is warm, warm summer temperature extremes occur with a probability of 20% and 24% in northern Europe and northeast Asia, respectively. In a cold North Atlantic phase, these probabilities are 0% and 8%. A similar dependence of the probability of occurrence for summer temperature extremes in these regions to North Atlantic SST can be found in observations.
To examine this effect in decadal predictions, we pool all available realizations for any given year in the decadal prediction system. Using 10 ensemble members and 10 lead years, we therefore end up with 100 realizations for any year between 1970 and 2018. We find that the probability of occurrence for summer temperature extremes in the pooled initialized climate predictions shows good agreement with the observations and the assimilation run. This agreement is related to high skill of the model system in predicting North Atlantic SST. Consequently, the likelihood of a warm summer temperature extreme occurring in the examined regions in the next 10 years can be inferred from predictions of North Atlantic temperature.
Impact of hydropeaking on groundwater flow and its implication for mixing
Authors: Chiogna Gabriele , Basilio Hazas Monica , Galli Matteo
Published: March 2020

The influence of heterogeneity occurring in natural porous media on spreading, dilution and mixing processes has been widely recognized in the literature, while less attention has been dedicated to investigating the influence of highly transient boundary conditions on the transport of contaminants in the subsurface. Mixing in groundwater flows is inefficient, but it can be greatly enhanced by transient conditions, which are commonly encountered in the environment. For example, surface water-goundwater interaction can be significantly affected by rapid fluctuations of the river stage caused by hydropower production (hydropeaking). In this work, we focus on the Adige valley aquifer, where river discharge of the Adige River and of the Noce River varies at multiple temporal scales due to seasonal (snow and glacier melt) and anthropogenic (i.e., hydropeaking) causes. To show how such fluctuations may affect the interaction between surface water and groundwater we present both experimental data of groundwater level, temperature and electrical conductivity and a model based interpretation of the data. Our study shows that the effect of hydropeaking on surface water - goundwater interaction varies for dry and wet years with important consequeces for solute transport.
Gamma-ray spectrometry observations to monitor a presumed meteoritic signature at Maâdna crater (Talemzane, Algeria)
Authors: Lamali Atmane , Hamai Lamine , Mokhtar Sid Ahmed , Yelles-chaouche Abdelkrim , Abtout Abdeslam , Merabet Nacer-Eddine , Bentridi Salah Eddine , Djadia Leila , Nadjemi Abdelmadjid
Published: March 2020

By measuring changes in radioelement concentrations, gamma-ray spectrometry is increasingly emerging as an efficient geophysical method that allows such changes to be geologically mapped according to lithology and soil type. At Maâdna crater in southern Algeria, this method has been used to monitor any changes in the composition of the target rocks that may be associated with the impact cratering process. For this purpose, several measurements were carried out in situ using a portable field gamma spectrometer. As a result, most predominantly calcareous surface lithologies, exposed on the rim and flanks of the crater, showed a very low emitted radiometric response over the three channels (K, Th, U). However, no more than 90 Cps were counted both inside and outside the crater. Such a rate is indeed expected in sedimentary rocks with low clay content, and this remains valid, as long as other exogenous mineralogical enrichments are excluded. On the other hand, the contoured radioelement concentrations maps, have demonstrated an anomalous enhanced gamma radiation levels of potassium-dominated peaks over the central part of the crater and in the surrounding wadis. Nevertheless, the central potassium anomaly is well correlated with the shallower magnetic one that has been described in previous studies (see e.g. Lamali et al., 2016). Therefore, either near the surrounding wadis or in the central part of this crater, this anomalously high level of radioactivity may be linked to an accumulation of later altered deposits. Consequently, there are no objective criteria to link these results to an impact event occurring at the Maâdna structure, similar to what was done at the Serra da Cangalha crater (Vasconcelos et al., 2012).
Application of waste lemon extract to rehabilitate the copper-contaminated farmland through gravitational soil flushing and stabilization
Authors: Fan Chihhao , Chang Pei-Wen , Huang Ya-Zhen
Published: March 2020

The present study aimed to investigate the effect of the waste lemon extract on the flushing treatment of the copper-contaminated soil collected from contaminated farmland, in which the copper concentration was measured as high as 2487 mg/kg. The soil flushing solution was prepared using the extract from collected waste lemons. The soil flushing treatment using the solution containing commercial citric acids was also conducted for comparison. Additionally, the waste lemon was used for soil rehabilitation after composting treatment.

The soil copper concentration treated with the solution containing waste lemon extract decreased more than that treated by the commercial citric acid solution at the comparable citric acid concentration. This is because the waste lemon extract solution contains additional co-dissolved organic substances other than citric acid and the flushing treatment had a higher retention time. For the treatment with lemon extract, the soil pH values were 4.56, 5.70 and 6.29 before, after lemon extract flushing and after compost treatment. The copper plant availability dropped from 677 mg/kg for the soil before flushing to 156 mg/kg after stabilization with composted waste lemon. Therefore, the citric acid flushing combined with stabilization was found effective for heavy metal removal in the soil environment.
An improved variational Data Assimilation method for ocean models with limited number of observations.
Authors: Sampson Lewis , Gonzalez-Ondina Jose M. , Shapiro Georgy
Published: March 2020

Data assimilation (DA) is a critical component for most state-of-the-art ocean prediction systems, which optimally combines model data and observational measurements to obtain an improved estimate of the modelled variables, by minimizing a cost function. The calculation requires the knowledge of the background error covariance matrix (BECM) as a weight for the quality of the model results, and an observational error covariance matrix (OECM) which weights the observational data.

Computing the BECM would require knowing the true values of the physical variables, which is not feasible. Instead, the BECM is estimated from model results and observations by using methods like National Meteorological Centre (NMC) or the Hollingsworth and Lönnberg (1984) (H-L). These methods have some shortcomings which make them unfit in some situations, which includes being fundamentally one-dimensional and making a suboptimal use of observations.

We have produced a novel method for error estimation, using an analysis of observations minus background data (innovations), which attempts to improve on some of these shortcomings. In particular, our method better infers information from observations, requiring less data to produce statistically robust results. We do this by minimizing a linear combination of functions to fit the data using a specifically tailored inner product, referred to as an inner product analysis (IPA).

We are able to produce quality BECM estimations even in data sparse domains, with notably better results in conditions of scarce observational data. By using a sample of observations, with decreasing sample size, we show that the stability and efficiency of our method, when compared to that of the H-L approach, does not deteriorate nearly as much as the number of data points decrease. We have found that we are able to continually produce error estimates with a reduced set of data, whereas the H-L method will begin to produce spurious values for smaller samples.

Our method works very well in combination with standard tools like NEMOVar by providing the required standard deviations and length-scales ratios. We have successfully ran this in the Arabian Sea for multiple seasons and compared the results with the H-L (in optimal conditions, when plenty of data is available), spatially the methods perform equally well. When we look at the root mean square error (RMSE) we see very similar performances, with each method giving better results for some seasons and worse for others.
Morphodynamic equilibrium of tidal bifurcations
Authors: Ragno Niccolò , Bolla Pittaluga Michele , Tambroni Nicoletta
Published: March 2020

Deltas are fascinating landforms subject to riverine (input of water and sediments) and marine processes (waves, tides) where bifurcations are the building block controlling the distribution of water, nutrient and sediment fluxes among the distributary channels of the network. In this work we focus on the role of tides as a key factor in controlling bifurcation behaviour. Recently it has been suggested and observed that tidal deltas (i.e. delta influenced or totally dominated by the tides) have the tendency to less numerous but more stable branches in comparison to fluvial-dominated deltas [Hoitink et al., 2017]. River bifurcations subject to unidirectional flow have been widely studied in the last decades. However, in the case of tidal bifurcations, the acting physical mechanisms and controlling factors are still not well understood, and a theoretical framework is still lacking. In order to fill this gap and understand how the stability and evolution of a delta could be affected by the tides, we investigate through an analytical model, the equilibrium configurations and stability conditions of a tidal bifurcation under the hypothesis of small tidal oscillations. In particular, we extend to the tidal case the previous works of Bolla Pittaluga et al. [2015] and Seminara et al. [2012] relative to the equilibrium and stability of a single bifurcation, and to the equilibrium of a single river dominated estuary, respectively. Results show that higher tidal amplitude and a closer position of the junction node to the sea, tends to hamper the development of unstable solutions, reducing the asymmetries in water and sediment fluxes between branches obtained when the upstream width-to-depth ratio falls above a critical value. Field observations of natural deltas seems to corroborate our findings.
Magnetohydrostatic modelling of the solar atmosphere: Test and application
Authors: Zhu Xiaoshuai , Wiegelmann Thomas
Published: March 2020

Both magnetic field and plasma play important roles in activities in the solar atmosphere. Unfortunately only the magnetic fields in the photosphere are routinely measured precisely. We aim to extrapolate these photospheric vector magnetograms upwards into  the solar atmosphere. In this work we are mainly interested in reconstructing the upper solar photosphere and chromosphere. In these layers magnetic and non-magnetic forces are equally important. Consequently we have to compute an equilibrium of plasma and magnetic forces with a magnetohydrostatic model. A optimization approach which minimize a functional defined by the magnetohydrostatic equations is used in the model. In this talk/poster, I will present a strict test of the new code with a radiative MHD simulation and its first application to a high resolution vector magnetogram measured by SUNRISE/IMaX.
Soils in archaeological structures of the southern Levant: archives of Holocene dust dynamics
Authors: Lucke Bernhard , Sandler Amir , Vanselow Kim André , Bruins Hendrik , Abu-Jaber Nizar , Bäumler Rupert
Published: March 2020

Ruins and archaeological structures in the southern Levant are often covered by initial soils that developed on debris. The fine grain size fractions of these soils may stem from aeolian sediments, and the ruins could serve as effective dust traps. The physical parameters and chemical composition of archaeological soils in hilltop ruins, cleanout spoils of cisterns, and ancient runoff-collecting terraces were determined in the Petra region in southern Jordan and the northern Negev in Israel. Different types of ruins could not be distinguished with regard to substrate composition. This indicates a predominance of aeolian processes for primary sedimentation, while fluvial processes only re-distribute aeolian material. In the Petra region, a significant local contribution from associated weathered rocks could be observed. Compared to modern settled dust, archaeological soils in southern Jordan are enriched with various major and trace elements associated with clays and oxide coatings of fine silt particles. In-situ weathering seems minimal, but preferential fixation of silt and clay by surface crusts (similar to desert pavements), and a role of moisture in sedimentation processes lead to increased sedimentation of calcareous silt. Contribution of rocks is negligible in the Negev due to greater rock hardness and abundant biological crusts sealing surfaces. Archaeological soils in the Negev and current settled dust consist of complex mixtures of local and remote sources, including significant portions of recycled material from paleosols. Archaeological soils in the southern Levant are archives of Holocene dust sources and aeolian sedimentation processes, with accretion rates exceeding those of Pleistocene hilltop loess in the Negev. Comparison with Pleistocene paleosols suggests that dust sources did not change significantly, but disappearance of snow could have reduced dust accumulation during the Holocene.
Forced and chaotic variability of basin-scale heat budgets in the global ocean: focus on the South Atlantic crossroads.
Authors: Penduff Thierry , Yan Fei-Er , Benabicha Imane , Molines Jean-Marc , Barnier Bernard
Published: March 2020

The OCCIPUT eddy-permitting (1/4°) global ocean/sea-ice 50-member ensemble simulation is analyzed over the period 1980-2015 to identify how the atmosphere and the intrinsic/chaotic ocean variability modulate the basin-scale Ocean Heat Content (OHC) at various timescales. In all regions of the simulated world ocean, the atmospherically-forced interannual OHC variability is driven by both air-sea heat fluxes (Qnet) and advective heat transport convergences (Conv), while the intrinsic component is driven by Conv, and damped by Qnet. 

We focus on the Atlantic sector of the Southern Ocean (SA), where the oceanic “chaos” explains 36 to 90% of the interannual and decadal heat transport variability across the limits of the basin, and 22% of this huge basin’s OHC variability at interannual and decadal timescales.

The model also simulates the Antarctic Circumpolar Wave (ACW) that was observed in the 80-90’s, with large impacts on OHC and heat transports in the Southern Ocean. This forced signal appears south of Australia, propagates eastward around Antarctica and northward into the Tropical Atlantic and the Tropical Indian Ocean. 

These results highlight the substantial contribution of large-scale low-frequency chaotic heat advection in eddy-active regions, and its major impact on decadal OHC variations over key basins. They suggest that climate simulations using eddying ocean models include an oceanic and random source of large-scale low-frequency variability whose atmospheric impacts remain to be assessed.
Solar wind temperature anisotropy and its influence on the spectrum of turbulence
Authors: Pitňa Alexander , Šafránkova Jana , Němeček Zdeněk
Published: March 2020

Nearly collisionless solar wind plasma originating in the solar corona is a turbulent medium. The energy within large scale fluctuations is continuously transferred into smaller scales and it eventually reaches scales at which it is converted into a random particle motion, thus heating the plasma. Although the processes that take place within this complex system have been studied for decades, many questions remain unresolved. The power spectra of the fluctuating fields of the magnetic field, bulk velocity, and ion density were studied extensively; however, the spectrum of the thermal velocity is seldom reported and/or discussed. In this paper, we address the difficulty of estimating its power spectrum. We analyze high-cadence (31 ms) thermal velocity measurements of the BMSW instrument onboard the Spektr-R spacecraft and the SWE instrument onboard the Wind spacecraft. We discuss the role of the proton temperature anisotropy (parallel/perpendicular) and its influence on the shape of the power spectra in the inertial range of turbulence.
Teleconnection patterns in the Southern Hemisphere in subseasonal to seasonal models hindcasts and influences on South America
Authors: Cavalcanti Iracema , Barreto Naurinete
Published: March 2020

The main atmospheric teleconnection patterns in the Southern Hemisphere are the Southern Annular Mode (SAM) and the Pacific South American (PSA). The SAM has opposite atmospheric anomalies between high and middle latitudes and it is linked with the polar vortex intensity and jet streams. PSA shows a wavetrain pattern from tropical to the extratropical atmosphere over the South Pacific Ocean triggered by convection in the tropical Indian, Maritime Continent and tropical Pacific. These modes modulate the atmospheric circulation variability and have an influence on the precipitation over Southern Hemisphere continents, mainly in South America (SA). Global models are able to represent these modes in climate simulations of seasonal timescale. The objective of this study is to analyse these teleconnections in hindcasts of subseasonal timescale and the relations to precipitation anomalies over South America. Predictions in the subseasonal time scale of austral summer are very important for several sectors of Southeastern and Southern regions of SA, as these are very populated regions and have agriculture and the largest hydropower,  which are very much affected by precipitation extremes, both excess and lack of rain. Two models of the S2S project (ECMWF and NCEP) are used for the summer seasons of 1999 to 2011 and the patterns are compared to ERA5 reanalyses and GPCP data. EOF analyses of geopotential at 200 hPa and regression analyses against precipitation show the patterns and the influences over South America. The SAM pattern is represented in predictions of 1 to 4 weeks in advance, and PSA pattern, from 1 to 3 weeks in advance. Then, the atmospheric circulation and meteorological variables composites of extreme positive and negative amplitudes of SAM and PSA are analysed to interpret precipitation anomalies during these specific periods for predictions of weeks 2 and 3.
Denitrification induced by plant residues is driven by water-soluble organic carbon
Authors: Surey Ronny , Schimpf Corinna M. , Sauheitl Leopold , Mueller Carsten W. , Rummel Pauline S. , Dittert Klaus , Kaiser Klaus , Böttcher Jürgen , Mikutta Robert
Published: March 2020

Denitrification usually takes place under anoxic conditions and over short periods of time and depends on readily available nitrate and carbon sources. Variations in CO2 and N2O emissions from soils amended with plant residues have mainly been explained by differences in their decomposability. Another factor rarely considered so far is water-extractable organic matter (WEOM) released into soil during residue decomposition. Here, we examined the potential effect of plant residues on denitrification with special emphasis on WEOM. A range of fresh and leached plant residues was characterized by elemental analyses, 13C-NMR spectroscopy, and extraction with ultrapure water. The obtained solutions were analyzed for the concentration of organic carbon (OC), organic nitrogen (ON), and by UV-VIS spectroscopy. To test the potential denitrification induced by plant residues or three different OM solutions, these carbon sources were added to soil suspensions and incubated for 24 hours at 20 °C in the dark under anoxic conditions; KNO3 was added to ensure unlimited nitrate supply. Evolving N2O and CO2 were analyzed by gas chromatography and acetylene inhibition was used to determine denitrification and its product ratio. The production of all gases as well as the molar N2O+N2-N/CO2-C ratio was directly related to the water-extractable OC (WEOC) content of the plant residues and the WEOC increased with carboxylic/carbonyl C and decreasing OC/ON ratios of the plant residues. Incubation of OM solutions revealed that the molar N2O+N2-N/CO2-C ratio and share of N2O are influenced by the WEOM’s chemical composition. In conclusion, the effect of plant residues on potential denitrification is governed by their composition and the related production of WEOM.
New insights into the complex surface faulting of the 1927 M8.0 Gulang earthquake, NE Tibetan Plateau
Authors: Guo Peng , Han Zhujun , Gao Fan , Zhu Chuanhua , Gai Hailong
Published: March 2020

The rupture patterns of large earthquakes in transpressional systems can provide important information for understanding oblique motion and strain partitioning between tectonic blocks. The 1927 M8.0 Gulang earthquake occurred on the transpressional boundary between the Tibetan and Gobi-Alashan blocks. Combined with the results of previous studies, we find that the Lenglongling fault (LLLF) and Southern Wuwei Basin fault (SWBF) might have both ruptured during the Gulang earthquake, but they exhibited different motions. A ~120-km-long surface rupture zone formed along the LLLF, with a left-lateral strike-slip motion and a coseismic offset of ~2.4-7.5 m. Bending, bifurcation, and change of the slip sense occurs at both ends of the fault. The ~42-km-long rupture zone on the SWBF, with a coseismic vertical offset of ~0.6-2.8 m, can be divided into two segments. The eastern segment shows thrust motion, while the western shows thrust motion with a left-lateral strike-slip component. Thus, the Gulang earthquake may be a multifault rupture event where strike-slip and thrust faults ruptured simultaneously. Analysis of deep and shallow structures and three-dimensional finite-element modeling reveal that the north-dipping LLLF and the SWBF may converge downward to a low-angle decollement. This pattern of deformation partitioning is similar to some other earthquakes where oblique block convergence is partitioned into strike-slip motion on steeply dipping faults and vertical motion on gently dipping faults.
A study on the Status of Earthquake Drills for Special Education Classes in Taiwan Elementary Schools
Authors: Ma Kuo-Chen , Wang Mei-Hung , Lee Mei-Hsiang , Chuang Mo-Hsiung
Published: March 2020

Under the influences of natural disasters, disabled people are often the majority of sufferers when a serious disaster happens. Third UN World Conference on Disaster Risk Reduction (3WCDRR) calls for agencies of the United Nations system, academia, the private sector, civil society, and people with disabilities to integrate the issue of the physically and mentally disabled into the new global framework for disaster reduction. Taiwan is one of the regions in the world where earthquakes occur very frequently. According to the statistics of the Taiwan Central Weather Bureau, an average of 23,000 earthquakes occurs in Taiwan each year, including about 1,000 sensational earthquakes. Earthquake prevention is therefore the essential task for campus disaster prevention and rescue programs. The school should recognize different evacuation abilities for students in special education classes, and know their special needs in earthquake disaster drills and emergency response ability.

In this study, four special education classes in elementary schools were selected as examples to understand the current situation in the engagement with earthquake drills by way of interviews and questionnaires. The evacuation abilities of students in special classes are classified into four categories based on the issues of physical environment, manpower arrangement, and both students’ and teachers’ educations in earthquake prevention. On the basis of the results, the conclusions regarding to those three issues can be drawn as follows. For the first issue concerning the physical environment, the teaching space for special education classes should consider the students’ evacuation abilities. Second, both internal and external support manpower should understand the students' evacuation capabilities and give different assistance based on their abilities. Last, the education goals in earthquake disaster prevention for students in different categories should be different. The earthquake drills should be well arranged in the aspects of time, place, equipment, and manpower assistance. It is important to note that special education teachers and assistants should have good knowledge in earthquake disaster prevention, understand the appropriate response to earthquake disaster, and strive to ensure the safety of students and themselves in the evacuation process.
Coupling Human - Earth Systems for Sustainability
Authors: Fu Bojie
Published: March 2020

Human influence on the natural environment has intensified, and the earth has entered the stage of Anthropocene. Earth surface processes are gradually dominated by human behavior, resulting in numerous resources, disasters and ecological problems. The ecosystem services of 60% are degradation in the world. The one of major challenges facing the world’s people are meeting the needs of people today and in the future, and sustaining atmosphere, water, soil and biological products which provided by ecosystems. We will present how to coupling human-earth system and propose the research priorities. They are: (1) Integrating research on multiple processes of water, soil, air and ecosystem; (2) Cascades of ecosystem structure, functions and services; (3) Feedback mechanisms of natural and social systems; (4) Data, models and simulation of sustainable development;(5) Mechanism, approach and policy of sustainable development. Finally, a case study in the Loess plateau of China, an area suffered from severe soil erosion in the world was taken. The changes in four key ecosystem services including water regulation, soil conservation, carbon sequestration, and grain production were assessed and the trade off among the ecosystem services were analysed under the changing landscapes due to the Chinese government’s implementation of the Grain to Green Program (GTGP). We found that ecosystem services convert significantly. The adaptive management strategy was discussed aiming on restoring and improving the sustainable capability of ecosystems providing services, based on the understanding of structure, function and dynamics of ecosystem.

 
Improving air quality forecasting with the assimilation of GOCI AOD retrievals
Authors: Ha Soyoung , Liu Zhiquan
Published: March 2020

The Korean Geostationary Ocean Color Imager (GOCI) satellite has monitored the East Asian region in high temporal and spatial resolution every day for the last decade, providing unprecedented information on air pollutants over the upstream region of the Korean peninsula. In this study, the GOCI Aerosol optical depth (AOD), retrieved at 550 nm wavelength, is assimilated to ameliorate the analysis quality, thereby making systematic improvements on air quality forecasting in South Korea. For successful data assimilation, GOCI retrievals are carefully investigated and processed based on data characteristics. The preprocessed data are then assimilated in the three-dimensional variational data assimilation (3DVAR) technique for the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). Over the Korea-United States Air Quality (KORUS-AQ) period (May 2016), the impact of GOCI AOD on the accuracy of air quality forecasting is examined by comparing with other observations including Moderate Resolution Imaging Spectroradiometer (MODIS) sensors and fine particulate matter (PM2.5) observations at the surface. Consistent with previous studies, the assimilation of surface PM2.5 concentrations alone systematically underestimates surface PM2.5 and its positive impact lasts mainly for about 6 h. When GOCI AOD retrievals are assimilated with surface PM2.5 observations, however, the negative bias is diminished and forecasts are improved up to 24 h, with the most significant contributions to the prediction of heavy pollution events over South Korea. The talk will be finished with an introduction of our ongoing efforts on developing the assimilation capability for more sophisticated aerosol schemes such as Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) and the Modal Aerosol Dynamics Model for Europe (MADE)-Volatility basis set (VBS).
Disturbance of the front region of magnetic reconnection outflow jets due to the lower-hybrid drift instability
Authors: Nakamura Takuma , Umeda Takayuki , Nakamura Rumi , Fu Huishan , Oka Mitsuo
Published: March 2020

Magnetic reconnection is a key process in collisionless plasmas that converts magnetic energy to plasma kinetic energies through changes in the magnetic field topology. The energy conversion in this process is believed to cause various explosive phenomena in space such as auroral substorms in the Earth’s magnetosphere and solar flares. Here, a 3D fully kinetic simulation shows that the lower-hybrid drift instability (LHDI) disturbs the front of magnetic reconnection outflow jets and additionally causes the energy dissipation. The peak energy dissipation at the jet fronts is comparable to the values seen near the center of the reconnection region where the topology change during reconnection occurs, indicating that the LHDI turbulence has a substantial effect on the energetics of reconnection. The result is well consistent with a disturbance observed at the dipolarization front (DF) in the Earth’s magnetotail by the Magnetospheric Multiscale (MMS) mission. A fully kinetic dispersion relation solver, validated by the MMS observations, further predicts that the disturbance of the reconnection jet front could occur over different parameter regimes in space plasmas including the Earth’s DF and solar flares.
Classification–coordination–collaboration: A system approach for advancing sustainable development goals
Authors: Zhang Junze , Fu Bojie , Wang Shuai , Zhao Wenwu
Published: March 2020

The 17 Sustainable Development Goals (SDGs) provide a blueprint for the world’s sustainable development plan throughout 2016 and 2030. It is regrettable that recent reports have shown that it will not be possible to achieve all the goals by 2030 under our current pace. To accelerate SDG implementation, scientists have conducted studies under a variety of perspectives, such as relationships among SDGs, their specific priorities, and necessary transformations. However, there still lacks a systematic approach to promote joint action by countries that can advance SDGs on regional, national, and global scales. To fill this gap, we summarize the relevant articles, reports, and practices in recent years on the ways to promote the implementation of the SDGs. Following this, we propose a systematic approach to combat this issue, namely, “classification–coordination–collaboration”. This approach not only considers relationships among the 17 SDGs and the links among the different management agencies, but it also contains the necessary means to accelerate SDGs. Overall, this approach is expected to promote the participation of countries within the process of global governance, and it will help to ensure that SDGs will realize key breakthroughs over the short-term while achieving sweeping progress over the long run.
Image Inpainting techniques for void filling in glaciological remote sensing products
Authors: Seehaus Thorsten , Eberhard Bänsch , Robert McNabb , Matthias Braun
Published: March 2020

Remote sensing offers the possibility to efficiently monitor glacier changes on large scales and in remote regions. Glacier surface elevation changes and surface velocities can be derived automatically from satellite acquisitions and provide information on the evaluation of glacier dynamics and mass balance. However, the obtained data sets are often affected by voids due to various issues depending on the imaging technique (SAR, optical). Those missing data on the one hand lead to uncertainties in the quantification of glacier changes, on the other hand can limit the assimilation of the data sets in glacier models.

Inpainting techniques were developed to remove distortions from photographs or for retouch purposes. In this study, suitable Inpainting techniques are applied on glaciological remote sensing products and evaluated in comparison with previous attempts.

For Glacier Bay Alaska, a nearly complete coverage of a glacier area of ~6000 km² by surface elevation change information exists. Artificial voids were generated and filled by using different Inpainting techniques and parameter. The inpainted data sets are evaluated in comparison to the original data set.
Investigating contrails within cirrus clouds
Authors: Bräuer Peter , Weikert Hanna , Tesche Matthias
Published: March 2020

Effects of aviation on the Earth’s radiation budget and climate related to CO2 emissions and from the formation of linear contrails and contrail cirrus have been the focus of detailed studies. Aviation effects on existing cirrus clouds are much less investigated. Contrail formation in existing cirrus clouds has the potential to increase the cloud optical thickness (COT) of optically thin cirrus, which might result in a net cooling effect.

Spaceborne remote sensing generally provides the means for studying the impact of aviation on climate. However, only active instruments such as lidar or radar can be used to study the effect of contrails that form within existing cirrus clouds. For such an investigation, the location of an aircraft at a given time needs to be matched with information on cloud coverage, cloud type, cloud layer height, and COT as can be retrieved from spaceborne CALIPSO lidar data.

We have developed an algorithm to find intersections of aircraft flight tracks with satellite tracks. Besides the spatial coordinates, the time difference between the passing of the aircraft and the satellite at the intersection is monitored and relevant aircraft data and satellite recordings are retrieved at the intersection. The algorithm is highly adjustable so that it can be adapted for other applications such as investigation of ship tracks or cloud tracking. The new algorithm has been used to identify aircraft flying through cirrus clouds in remote regions of the Earth to study the effects of individual aircraft on existing cirrus.