bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of a new scale-aware three-dimensional subgrid mixing parameterization on the simulations of tropical cyclone
Authors: liu mengjuan , Zhang Xu
Published: March 2020

A new scale-adaptive three-dimensional (3D) turbulent kinetic energy (TKE) subgrid mixing scheme is developed using the Advanced Research version of the Weather Research and Forecasting Model (WRF-ARW) to address the gray-zone problem in the parameterization of subgrid turbulent mixing. This scheme is based on the full 3D TKE prognostic equation and combines the horizontal and vertical subgrid turbulent mixing into a single energetically consistent framework.

A series of real tropical cyclone(TC) simulations with varying horizontal resolutions from 9km to 1km are carried out to compare the performance of the 3D mixing scheme and the conventional 1D planetary boundary layer (PBL) schemes to the observations, including conventional ones such as radiosonde and surface synoptic observations, as well as intensive ones obtained during the landfall of TC, such as mobile boundary layer wind profiler and Dual-pol Doppler Radar. This study aims to determine if the new scheme performs appropriate on TC simulation, and to evaluate the sensitivity of TC simulation to boundary layer schemes.
Revealing a temporal symmetry/asymmetry dichotomy in a Markovian setting, and a parameterization based on fractional low-order joint moments
Authors: Carsteanu Alin Andrei , Langousis Andreas
Published: March 2020

We show that "an arrow of time", which is reflected by the joint distributions of successive variables in a stochastic process, may exist (or not) solely on grounds of marginal probability distributions, without affecting stationarity or involving the structural dependencies within the process. The temporal symmetry/asymmetry dichotomy thus revealed, is exemplified for the simplest case of stably-distributed Markovian recursions, where the lack of Gaussianity, even when the increments of the process are independent and identically distributed (i.i.d.) with symmetric marginal, is generating a break of temporal symmetry. We devise a statistical tool to evidence this striking result, based on fractional low-order joint moments, whose existence is guaranteed even for the case of "fat-tailed" strictly-stable distributions, and is thereby suited for parameterizing structural dependencies within such a process.
Numerical investigation of sediment-charged flash flood due to a cascade of natural dam failures
Authors: Guan Mingfu
Published: March 2020

Landslide natural dams are commonly formed in a river valley of mountainous areas due to heavy rainfall or earthquake, which can be a complete or partial blockage. Different from conventional man-made dams, natural dams typically comprise unconsolidated and poorly sorted material, and are vulnerable to failure and breaching in short period due to overtopping or seepage. For those small sediment blockage in a river valley, their failures frequently occur during high intense rainfalls, which will induce a large flash flood with high-concentrated sediment downstream in a short period, and the magnitude is likely to be amplified along the flow direction due to the inclusion of a large amount of sediment. This can result in significant and sudden debris flow or high sediment-charged flash flood in the downstream for human life and property. Cascade failures of a series of natural dams in a gully have been considered to be a primary reason for the enlargement of high sediment-laden flash flood. In general, cascading natural dams can be formed along the sloping channel due to the randomness and unpredictability of landslides, which complexes the hydraulics of landslide dam failures.

This study evaluates the formation and development of sediment-charged flash floods due to cascading failure of natural dams through detailed hydro-morphodynamic modelling. The model used is based on shallow water theory and it has been successful in predicting the flow and morphological process during sudden dam-break, as well as full and partial dyke-breach.  The study first calibrates the model with experiemntal data of a cascade of partical blockage dam failures. Then the calibrated model is applied to two types of natural dam failure cases: (1) straight steep slope channel with a series of small partial blockage dams; (2) bend channel with steep slope including a series of partical blockage dams. For both cases, various scenarios are modelled, including: (1) failure of a single dam in a sloping channel, (2) failure of two dams in a sloping channel, (3) failure of multiple landslide dams (four) in a sloping channel. Based on the detailed model results, the study systematically explores the tempo-spatial evolution of sediment-charged flash floods (discharge, flow velocity, and flow concentration) and geomorphic properties along the steep sloping channel.  The effects of in-channel erosion and flow-driven sediment from dams on the evolution of flood dynamic process are analysed.  The results improve the understanding of the formation and development mechanism of flash floods due to cascading landslide dam failures.  The findings are beneficial for downstream flood risk assessment and developing control strategies for landslide-induced floods.
Iron, primary production and an oxygen minimum zone feedback mechanism
Authors: Hopwood Mark , Paul Allanah , Browning Thomas , Freund Madeleine , Tanhua Toste , Rapp Insa , Gledhill Martha , Achterberg Eric
Published: March 2020

In regions bordering productive eastern-boundary upwelling systems, extensive O2 minimum zones (OMZs) develop along the ocean shelf. Enhanced sedimentary release of Fe and PO4 under these low O2 conditions could drive enhanced N2-fixation and primary production in the ocean, thus ultimately increasing O2 consumption, and potentially creating a positive feedback to ocean deoxygenation. A similar feedback loop has been identified in shallow and enclosed coastal regions such as the Baltic where primary production is controlled primarily by N and P bioavailability, but it is unclear to what extent a similar mechanism operates at a larger scale in the open ocean where productivity is proximally constrained by Fe and/or N availability. This is largely because of uncertainties in the fate of the Fe released from shelf sediments.

Here we present extensive Fe measurements from a series of 5 cruises and a mesocosm experiment on the Peruvian shelf which combined extensive measurements of Fe distribution with an inert tracer release experiment, to quantify off-shelf transport, and N2 fixation rates. As expected for a region with among the highest reported benthic Fe fluxes in the world, dissolved Fe concentrations were generally elevated along the inner-Peruvian shelf reaching >60 nM. Whilst concentrations rapidly declined across the shelf, reaching as low as 0.01 nM after the shelf break, ‘pockets’ of 1-2 nM elevated Fe concentrations were evident in some transects suggesting a significant role of eddies in off-shelf transport which was verified by the results of our CF3SF5 tracer release experiment. Never-the-less, benthic Fe release was rapidly attenuated close to the sediment interface, with the vast majority of Fe loss occurring on timescales of <1 day and spatial scales of <1 km. Evidence of Fe limitation was even found at some stations on the Peruvian shelf questioning the efficiency with which Fe released from sediments is able to positively influence marine primary production. Despite an excess of P across the region with respect to biological requirements, and extremely high inner-shelf Fe concentrations, N2 fixation rates remained consistently low across the region (0-0.8 nmol N L-1 d-1). Furthermore, the maximum lateral transfer of Fe was de-coupled spatially from maximum benthic Fe release, limiting the potential for a P/Fe-fueled positive feedback loop to OMZ expansion.
Target observation of mesoscale eddies in the ocean
Authors: Jiang Lin , Duan Wansuo
Published: March 2020

Previous studies show that the kinetic energy of mesoscale eddies (MEs) accounts for more than 80% of the global ocean energy. The theoretical study and numerical simulation of MEs will enable us to better understand the dynamics of ocean circulation. Weiss and Grooms (2017) found that assimilating uniform observations taken over MEs is much better than assimilating a subset of observations on a regular grid for improving prediction skill of SSH associated with ocean state. In the present study, we use a conditional nonlinear optimal perturbation (CNOP) approach to investigate the sensitivity of the ocean state sea surface height (SSH) predictions on MEs with a two-layer quasi-geostrophic model and show the optimal assimilating scheme. In the study, the CNOPs of SSH predictions are first computed. It is found that, if one regards the regions covered by the grid points with large values of CNOPs as sensitive area of SSH predictions, the sensitive areas are mainly located on MEs. Furthermore, the stronger the MEs, the more the MEs grid points covered by the sensitive area. Especially, these grid points associated with sensitive areas are not uniformly distributed over the MEs. It is obvious that the predictions of SSH are quite sensitive to the initialization of MEs (especially that of the particular region of large values of CNOPs for strong MEs, rather than of the uniformly distributed grid points over MEs). Therefore, an appropriate initialization of MEs is much helpful for improving the prediction accuracy of SSH. And the CNOPs of SSH prediction here may provide useful information on how to improve initialization of MEs.
Soil Erosion in Mesic Forests: How do Biological Soil Crusts affect sediment transport and surface runoff?
Authors: Gall Corinna , Nebel Martin , Quandt Dietmar , Sauer Michael , Scholten Thomas , Seitz Steffen
Published: March 2020

Soil erosion under forests occurs if forest layers get disturbed. Disturbances may arise from treefall, forest road works, skid trails or deforestation. In these disturbed areas, both an intact canopy and forest floor cover are missing, so that forest soils lack protection against water erosion. To counteract these negative effects a quick restoration of soil surface covers by vegetation is important. In particular, biological soil crusts (biocrusts) are able to quickly colonize gaps in higher vegetation and they are known to reduce soil erodibility. So far, the focus of biocrust research has been in drylands, whereas biocrusts have proven to be an important factor in mesic environments, especially as a pioneer vegetation in disturbed areas.

In this study, the natural succession of biocrusts in skid trails was observed on four different underlying substrates in a temperate European forest ecosystem (Schönbuch Nature Park in the state of Baden-Württemberg, Germany) and their influence on surface runoff, sediment discharge and nutrient relocation was investigated. Therefore, 144 micro-scale runoff plots (ROPs, 40 x 40 cm) were established with four replicates in the wheel tracks as well as in the center tracks and two replicates on undisturbed forest soil. In order to initiate splash and interrill erosion, four rainfall simulations were carried out from spring to winter with a constant intensity of 45 mm h-1. With the purpose to compare these small-scale erosion rates with a larger scale, additional turbidity sensors were installed in the catchment area. The biocrust succession was determined by regular vegetation surveys with a classification of mainly mosses and liverworts up to the species level. Additionally, DNA samples of the upper soil layer were collected to conduct DNA extractions specify other potential biocrust organisms such as lichens, cyanobacteria, fungi and algae.

First results show that surface runoff and sediment discharge are higher in the wheel track than in the center track and that both parameters are reduced with a higher developmental stage of soil surface cover. The vegetation survey demonstrates a quick development of moss-dominated biocrusts from April to October with up to ten different species in one ROP. Depending on the location of the skid trail, a quick development of the higher vegetation was observed as well. Lab work on nutrient relocation and DNA analysis is still in progress and further results will be presented at the EGU 2020.
CompoundEvents: An R package for statistical modeling of compound climate and weather events and their impacts
Authors: Hao Zengchao , Hao Fanghua , Zhang Xuan
Published: March 2020

Extremes, such as droughts, floods, heatwaves, and cold waves, may trigger large impacts on human society and the environment. The concurrent or consecutive occurrences of these extreme events (i.e., compound events) may result in even larger impacts than those caused by isolated extremes. Compound weather and climate extremes have attracted much attention in recent decades due to their disastrous impacts on the environment, ecosystem, and socioeconomics. It is thus of particular importance to improve our understanding of their properties, mechanisms, and impacts. Different methods for analyzing compound events and their impacts have been developed in recent decades. In this study, we introduce an R package for statistical modeling and analysis of compound events using compound precipitation and temperature extreme as examples. There are multiple components in this package, including the characterization, driver assessments, prediction, attribution, and impacts of compound events. For example, after extracting compound events based on the threshold of each variable, the package can be employed to assess the driving factors of compound events and predict their occurrences. The impact of compound events on different sectors (e.g., crop yield, vegetation) can also be assessed based on the multivariate model embedded in this package. This package is expected to be useful for compound events modeling and analysis for both researchers and decision-makers.
Estimating aircraft emissions at Frankfurt airport using the DOAS technique
Authors: Uhlmannsiek Katharina , Lauster Bianca , Dörner Steffen , Donner Sebastian , Beirle Steffen , Wagner Thomas
Published: March 2020

For the last decades, civil aviation traffic increased rapidly. At Frankfurt airport more than 700 flights depart per day (5h to 23h) i.e., take-offs take place approximately every two minutes. Like many other engines, an airplane’s engine uses fossil fuel primarily emitting carbon dioxide (CO2) and water vapour (H2O). However, high combustion temperatures also lead to a significant amount of nitrogen oxide (NOx) emission. NOx has a large impact on atmospheric chemistry and is harmful to human health. As airports are usually built in highly populated areas, these pollutants affect the health of the inhabitants in the region. Only few measurements have directly investigated emissions of airplanes under real atmospheric conditions during take-off as these measurements are typically difficult to perform.

In this work, we show the applicability and first results using Multi AXis Differential Absorption Spectroscopy (MAX-DOAS) measurements to directly determine airplane emissions during take-off at Frankfurt airport. Therefore, the MAX-DOAS instrument is mounted in extension of the runway, about 500 m below the typical altitude of the departing aircrafts to measure a spectrum of scattered sun light through the exhaust plume. Using a wide aperture of the entrance optics at one fixed elevation instead of scanning across the plume allows capturing the whole plume with one simultaneous measurement. In that way, the induced NO2 emission of each passing aircraft can be determined. The obtained NO2 emissions are then used to estimate the total emissions of nitrogen oxides. 
Pumpellyosite alteration in the oceanic crust as marker of chemically evolved hydrothermal discharge and its relation to volcanogenic massive-sulphide (VMS) deposits
Authors: Weber Samuel , Diamond Larryn William
Published: March 2020

Reactions of seawater and fresh basalts below the seafloor are crucial for the formation of black-smoker type volcanogenic massive sulphide (VMS) deposits. Improved understanding of hydrothermal alteration processes can therefore help to improve the genetic model of VMS deposits, facilitating targeting in mineral exploration. Reactions of downwelling seawater with fresh basalts creates Ca-depleted, Mg- and Na- enriched “spilite” alteration (albite+chlorite+hematite+titanite±augite±epidote±quartz±calcite). The fluid in turn becomes enriched in Ca and depleted in Mg and Na. This chemically evolved, upwelling fluid can create Ca-enriched, Mg- and Na-depleted “epidosite” alteration (epidote+quartz+titanite+hematite). Epidosites have often been proposed as being the source-rocks for metals in VMS deposits. The more rarely described “pumpellyosite” alteration (pumpellyite+quartz+titanite) exhibits a very similar metasomatism to epidosite alteration and is assumed to represent the low-T equivalent of epidosite alteration.

            We recently discovered large, km2-sized areas of pumpellyosite alteration in the Semail ophiolite (Oman), allowing us to study the transition from epidosite to pumpellyosite alteration. We use reactive-transport modelling to investigate the mechanism responsible for the change from epidosite to pumpellyosite alteration. Pumpellyosite alteration was observed up to few meters below the palaeo-seafloor, indicating that evolved fluids discharged directly onto the seafloor. However, no sulphide mineralisation was observed on or below the palaeo-seafloor. This observation makes the involvement of pumpellyosite alteration in the VMS-forming system questionable. The metasomatic fingerprint of pumpellyosite alteration also strongly contrasts with the chlorite-quartz alteration typically found below VMS deposits. Since epidosite and pumpellyosite alteration appear to be genetically linked, epidosites may likewise be unrelated to the genesis of VMS deposits.
Can combined application of biochar and nitrogen promote microbial functions and root plasticity for plant growth in low-fertile soils?
Authors: Song Xiaona , Razavi Bahar , Ludwig Bernard , Zamanian Kazem , Zang Huadong , Kuzyakov Yakov , Dippold Michaela , Gunina Anna
Published: March 2020

Biochar and nitrogen (N) fertilizers are frequently applied to improve soil properties and increase crop productivity. However, it remains unclear how root plasticity, soil enzyme activities, N and (phosphorus) P cycling in plant-soil system are changed after application of biochar, N or their combination. To address these questions, left and right parts of rhizoboxes were filled with silty-clay loam subsoil amended with biochar (15 g kg-1 soil, wheat straw, 300 °C), N (0.05 g KNO3-N kg-1 soil) or a control (no amendments), resulting the following combinations (Cm): biochar/control (Cm1), N/control (Cm2) and biochar/N (Cm3). One seed of maize (Zea mays L.) was planted in the middle of each rhizobox, thus allowing roots to choose freely the growth direction. Root growth was quantified by a photographic approach constantly during the experiment (30 d), and soil enzyme activities, available N and P, root morphology and plant biomass were analyzed after plant harvest.

Maximum plant biomass was found for biochar/N application (0.91 g), whereas minimal values was for biochar/control (0.56 g). At the same time, decreased soil bulk density and increased availability of P in the biochar compartment (Cm1 and Cm3) stimulated root length by 1.4-1.8 times – an effect which was independent from the presence of N in the same rhizobox. Together with stimulated activities of ß-glucosidase and leucine aminopeptidase (by 33%-39%) in presence of biochar (Cm3) compared to N, this shows the coupling of C, N and P cycles in biochar/N treated soils. Application of N (Cm2) also increased ß-glucosidase activity compared to control soil, whereas root elongation stayed unaffected. Thus, combined application of biochar/N over-win benefits of biochar or N alone for plant growth, which is linked with i) the stimulation of microbial enzyme activity at the biochar locations to reduce C and N limitation for both plant and microorganisms, and ii) increasing of fine root proportion to improve N utilization efficiency in the N-treated compartment. Thus, strategy of combined biochar/N application can not only improve the above-ground biomass production, but also increase root-microorganism interactions to overcome nutrient limitation in low fertile agricultural soils.
Assessment of the wave attenuation capacity of a mangrove forest based on its age and the incident wave conditions
Authors: Maza Maria , Lara Javier L. , Losada Iñigo J.
Published: March 2020

Although mangroves reduce annual flooding to millions of people there is not a methodology to implement these solutions and it is still difficult to estimate the protection provided by them under different environmental conditions and ecosystem properties. To move forward in the consecution of an engineering approach when implementing these solutions for coastal defense, the first step to make is to better understand and parameterize the basic physical processes involved in flow-mangroves interaction. With the aim of getting a new formulation for wave decay provided by Rhizophora mangrove forests based on flow and ecosystem properties, an experimental campaign was carried out where both wave attenuation and forces on mangrove individuals were measured under different wave conditions. Both, the hydrodynamic conditions and the mangrove forest, were scaled according to field conditions for short waves. The detailed wave attenuation and drag force measurements obtained in these experiments allowed to obtain new formulations of wave decay produced by the forest depending on the flow, i.e.: water depth, wave height and period, and on the forest characteristics, i.e.: individuals submerged solid volume fraction and density. These formulations are used to get attenuation rates under different flow and ecosystem conditions. The resultant curves provide with the wave decay produced by a specific Rhizophora forest subjected to the defined wave conditions. The forest is defined on the basis of its age, considering the differences in individual trees depending on their maturity and the density of the forest as the number of trees per unit area. Wave conditions are defined by the root mean square wave height and the peak period and water depth is also considered. The obtained curves allow to estimate the width of the forest necessary to reach a certain level of protection considering the local flow conditions and the forest age. This can assist in the inclusion of nature-based solutions in the portfolio of coastal protection measures.
Risk of crop-failure due to compound hot and dry extremes in the Iberian Peninsula
Authors: Ribeiro Andreia , Russo Ana , Gouveia Célia , Páscoa Patrícia , Zscheischler Jakob
Published: March 2020

Crop health and favourable yields depend strongly on precipitation and temperature patterns during the crop’s growing season. Compound events, such as co-occurring drought and heat can lead to extreme crop failure and cause larger damages than the impacts of the individual drought or heat alone.

Here we assess the relative role of hot and dry conditions (HDC) in crop yields and evaluate in what manner compound HDC enhance the probability of failure in rainfed cropping systems in the Iberian Peninsula. We use annual wheat yield data at the province level and cluster provinces with similar sensitivities of yields to climate conditions. Copula theory was applied to model the trivariate dependence between 3-monthly means of maximum temperature, 3-monthly means of precipitation and wheat yields. The climate variables and averaging periods have been chosen to maximize the dependence between the driver climate conditions during growing season and the annual yields. Copulas enable for the estimation of conditional probabilities of crop-loss under different hot and dry severity levels based on their trivariate joint distribution.

Our results demonstrate that the probability of wheat loss increases with the severity of the compound HDC and that losses are significantly larger during co-occurring drought and heat compared to individual water- or heat-stress. Moreover, the difference between heat impacts and compound heat and drought related impacts is larger than the difference between drought impacts and compound heat and drought related impacts, suggesting that water-stress is the major driver of wheat losses. These findings can help contribute to design management options to mitigate climate-related crop impacts and guide the decision-making process in agricultural practices.

Acknowledgements: A.F.S.Ribeiro would like to acknowledge the financial support through FCT (Fundação para a Ciência e a Tecnologia, Portugal) under the projects UIDB/50019/2020 – IDL and PTDC/CTA-CLI/28902/201 (IMPECAF). A.F.S.Ribeiro is also thankful to FCT for the grant PD/BD/114481/2016 and to the COST Action CA17109 for a Short Term Scientific Mission (STSM) grant to develop the present work.
Identification of the spatial and temporal variation of groundwater level in Beijing plain via the fusion of remotely sensed data and ground observation data
Authors: Lu Jiayun , Lu Chengpeng , Sun Long , Qin Wei
Published: March 2020

Predicting groundwater level changing accurately is important to ensure the sustainable and efficient utilization of water resources. The study of groundwater model generally includes multi-source of data as input. The spatial and temporal patterns of groundwater is associated with surface water and rainfall, resulting in the difficulty of groundwater level predicting. Satellite data has been gradually valued and utilized more popularly. The effective fusion of remotely sensed data and ground observation data will greatly improve the spatial and temporal resolution of groundwater level mapping. At present, most of the models used solely the ground data or remote sensing data for prediction. The development and application of data analysis technology will effectively improve the level of prediction. How to merge multi-source data to enhance the accuracy is the goal of the study. In this study, the Beijing plain area will be selected as a typical research. Ground observed data and satellite remotely sensed data will be unified used for data fusion to predict groundwater dynamics. The groundwater level distribution after multi-source data fusion is simulated to analyze the evolution trend and spatial patterns of groundwater level in Beijing plain over the years. Analyzing the difference between single source data and multi-source data fusion is another goal in this study.
Finding the Information of the Unknown DNAPL Residual Source using various tracer data, Wonju, Korea
Authors: Lee Seong-Sun , Cho Il-Ryoung , Ju Yeojin , Lee Kang-Kun
Published: March 2020

In this study, analytical solution method which can evaluate and quantify the impacts of partial mass reduction by remedial action performed in study site is applied to estimate the unknown DNAPL source mass and dissolved concentration using long-term monitoring data collected from 2009 to 2019. Also, noble gas tracer method was applied to identify the partitioning processes which can be happened in TCE contaminated site. By using the source zone monitoring data during about 10 years and analytical solution, initial dissolved concentration and residual mass of TCE in spilled period at the main source zone were roughly estimated 150 mg/L and 1000 kg, respectively. These values decreased to 0.45 mg/L and 33.07 kg direct after an intensive remedial action performed in 2013 and then it expected to be continuously decreased to 0.29 mg/L and 25.41 kg from the end of remedial actions to 2020. From results of quantitative evaluation using analytical solution, it can be evaluated that the intensive remedial action had effectively performed with removal efficiency of 70% for the residual source mass during the remediation period. From the results of noble gas analysis, the distance from TCE source zone was divided into three groups from Zone 1 to 3. Zone 1 includes samples that are the closest from the TCE main source, and are highly partitioned to TCE compared to other zones. Zone 3 samples show least accordance with either of the fractionation lines, showing that sampling points are influenced highly by other mechanism rather than partitioning to TCE. Also, it is identified that seasonal variation of groundwater level can be affected to the distribution of noble gas at around TCE source zone. Samples from only “High TCE” zone are plotted along with ideal batch equilibrium and Rayleigh fractionation line again and divided into two groups according to their sampling date. From August 2018 to October, 2018, samples shift from right to left in the figure, getting closer to Rayleigh fractionation line. In August, noble gas was relatively in equilibrium between groundwater and TCE. However, as water table rises, noble gas became touch with residual TCE locating above the previous water-level, which is a receiving fluid in water-TCE system. Results of this study was support that it was able to estimate the unknown quantitative information for TCE contamination and noble gas as the indicator of DNAPL contamination could be applied in allocating the DNAPL source which is relatively hard to estimate.
Insights into the EMEP emissions inventory dataset
Authors: Schindlbacher Sabine , Brendle Christine , Mareckova Katarina , Matthews Bradley , Pinterits Marion , Tista Melanie , Ullrich Bernhard , Wankmüller Robert
Published: March 2020

Under the Convention on Long-range Transboundary Air Pollution (CLRTAP), 51 northern hemisphere countries are obliged to regularly report their national emissions inventories for selected anthropogenic air pollutants to the United Nations Economic Commission for Europe (UNECE). The EMEP Centre on Emissions Inventories and Projections (CEIP) of the Convention is tasked with administering, archiving and reviewing these data and compiling the EMEP emissions dataset, a complete and gridded inventory for the area between 30 and 82 °N and 30 °W and 90°E.

The reported national emissions inventories and the EMEP emissions dataset are often used by the scientific community as input drivers of air pollution models or as priors for inverse estimation of emissions. However, interpreting model outputs, validation and uncertainties may be restricted by limited knowledge of the peculiarities of such reported data. The purpose of this conference contribution by CEIP is to provide atmospheric modellers with further insight into these reported emissions data. The presentation will introduce the Convention and discuss how complexities of this international agreement have led to diversified reporting requirements and heterogeneity in the frequency and quality of the reported inventories. Current issues with respect to emissions of particulate matter (e.g. reporting of condensable particulate matter and black carbon) will furthermore be discussed and the presentation will also provide perspectives on how the recently agreed long-term strategy for Convention may impact future emissions reporting over the next decade and beyond.
Spatial resolution dependence of ion-scale waves in a global-hybrid Vlasov simulation
Authors: Dubart Maxime , Ganse Urs , Osmane Adnane , Battarbee Markus , Grandin Maxime , Johlander Andreas , Pfau-Kempf Yann , Turc Lucile , Palmroth Minna
Published: March 2020

Plasma waves are ubiquitous in the Earth's magnetosheath. The most observed waves arise from instabilities generated by temperature anisotropy on the ions and electrons, such as the mirror and proton cyclotron instabilities. Along with observations, space physics is increasingly relying on the support of numerical simulations to understand these waves and instabilities. However, numerical simulations come with resolution limitations. We investigate here the spatial resolution dependence of the mirror and proton cyclotron instabilities in a global-hybrid Vlasov simulation with the use of the Vlasiator model. We compare the proton velocity distribution functions, power spectrum and growth rate of the instabilities in a simulation with three different spatial resolutions. We find that the proton cyclotron instability is absent at the lowest resolution and that the mirror instability is dominating, increasing the overall temperature anisotropy of the simulation. We also conducted a test at higher resolution and found out that this does not improve the description of the proton cyclotron instability significantly enough to justify this increase in resolution at the cost of numerical resources in future simulations. These results will be used for a future sub-grid model in order to mimic the energy dissipation processes at work at smaller scales without increasing the resolution of the simulation.
Investigating chemical composition of the troposphere over the Russian Arctic using the "Optik" Tu-134 aircraft laboratory
Authors: Belan Boris D. , Antokhin Pavel N. , Arshinov Mikhail Yu. , Belan Sergey B. , Davydov Denis K. , Ivlev Georgii A. , Kozlov Artem V. , Ptashnik Igor V. , Savkin Denis E. , Simonenkov Denis V. , Tolmachev Gennadii N. , Fofonov Alexandr V.
Published: March 2020

The need to undertake a comprehensive investigation of the atmospheric composition over the Russian segment of the Arctic is caused by a serious lack and irregularity in obtaining observational data from this regio of the Earth. In addition, a comparison of the aircraft in-situ measurements with satellite data retrieved for the Kara Sea region in 2017 revealed large uncertainties in determining the vertical distribution of greenhouse gas concentrations using remote sensing methods. The development and improvement of the last ones needs at least their periodic verification by means of undertaking precise in-situ aircraft measurements.

The general scheme of the proposed experiment is as follows (map is attached): flight from Novosibirsk to Naryan-Mar via Sabetta. From Naryan-Mar, flight to a water area of the Bering Sea (up to 1000 km). Flight from Naryan-Mar to Sabetta. From here, flight to a water area of the Kara Sea (up to 1000 km). Then, flight to Tiksi. Flight from Tiksi to a water area of the Laptev Sea (up to 1000 km). Flight to Chokurdakh or Chersky. From there, flight to a water area of the East Siberian Sea (up to 1000 km). Flight to Cape Schmidt. Flight to a water area of the Chukchi Sea (up to 1000 km). Return route: Cape Shmidt–Chersky (or Chokurdah)–Yakutsk–Bratsk–Novosibirsk. It will take about 100 hours of flying time to implement the entire aircraft campaign. Campaign period is about 2-3 weeks. It is better to undertake the campaign during summer when the ocean is open. Flights over the land surface are assumed to be undertaken from 0.5 km to 11 km above ground level while above the sea from 0.2 km to 11 km. The flight profile is variable from the maximum possible height to the minimum allowed one. Vertical profiles of gas and aerosol composition will be obtained, including black carbon and organic components, as well as basic meteorological quantities.

Satellite data will be verified that do not yet provide acceptable accuracy. For the first time, unique information will be obtained over the least explored region of the Arctic, which is crucial for the whole planet in terms of climate formation and the impact of global warming.
Comparative Analysis of non-linear position variations using the time series of station coordinates in some ITRF co-location sites
Authors: Lian Lizhen , Huang Chengli , Zhang Jin
Published: March 2020

The reprocessed time series (weekly from SLR, daily from GNSS, and 24h session-wise from VLBI) of co-located station position solutions spanning their full observation histories up to the end of 2014 are analyzed with the goal to detect nonlinear time-variable effects in station positions, such as periodic variations or discontinuities caused e.g. by instrumental changes or earthquakes. This information is then used to assess the reliability of the results about the nonlinear changes of all technique stations in each colocation site since they can be verified with each other. Next, the iterative adjustment is performed, i.e. jumping changes, post-seismic deformation and periodical signals are determined altogether for accurate estimation of station velocity. Finally, the information of the relative motion among the stations equipped with different technique instruments per colocation site is determined which can offer a reference for the necessary arrangement of local resurvey in the future.
Conifer wood biochar as an amendment for agricultural soils in South-Tyrol: impact on greenhouse gases emissions and soil carbon stocks
Authors: Criscuoli Irene , Ventura Maurizio , Wiedner Katja , Glaser Bruno , Panzacchi Pietro , Ceccon Christian , Petrillo Marta , Zanotelli Damiano , Andreotti Carlo , Tonon Giustino
Published: March 2020

Biochar is a carbonaceous material produced through the pyro-gasification of biomass. In the last decade, biochar has been proposed as a soil amendment because it can improve soil physico-chemical properties and carbon stocks, contributing to climate change mitigation.

In the framework of the Wood-Up project (Optimization of WOOD gasification chain in South Tyrol to prodUce bioenergy and other high-value green Products to enhance soil fertility and mitigate climate change, FESR1028), we studied the impact of conifer wood biochar on the emissions of the main greenhouse gases (GHGs) from the soil: carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), as well as on the soil carbon stock of agricultural fields in South Tyrol.

In May 2017, 25 and 50 t ha-1 of pure biochar and biochar mixed with compost (45 t ha-1), were applied to the soil of a vineyard near Merano (South-Tyrol, northern Italy) following a randomized block experimental design with four replicates per treatment.

Soil GHGs fluxes were monitored from June 2017 until December 2019. Fluxes were measured, in real time, with a high-resolution portable multi-gas analyzer based on cavity ring-down spectroscopy technology (Picarro inc., Santa Clara, CA, USA) connected to an automated dynamic chambers system (Eosense Inc., Dartmouth, NS, Canada). Gas emissions were measured monthly and were related to soil temperature and moisture to evaluate the impact of treatments on the sensitivity of GHGs fluxes to environmental parameters. The stability of conifer wood biochar in soil was assessed through the quantification of the Benzene PolyCarboxylic Acids (BPCA), specific biomarkers of black carbon, over time. The BPCA content in the soil was measured before the application of biochar and compost, three weeks after the application and two years later.

During the first year of experiment, in biochar-amended soils, we observed a reduction of the temperature sensitivity of all GHGs fluxes in comparison to treatments without biochar (control and compost alone). In the second and third year an opposite trend was observed, with an increase of temperature sensitivity of GHGs fluxes in biochar-treated soil. The change of biochar effect over time might be linked to biochar ageing in soil. However, a role of soil moisture cannot be excluded, as it was higher in the first year of experiment. The experimental results will be presented in the broader context of the Wood-Up project.
A Quantitative Assessment of the Impact of Increase in CO2 Concentration on Baroclinic Instability
Authors: Kaviani Mahshid , Ahmadi-Givi Farhang , Mohebalhojeh Ali. R. , Yazgi Daniel
Published: March 2020

CO radiative effects has been investigated for a short period relevant for the duration of baroclinic instability. For this purpose, the RRTMG radiative parameterization scheme has been coupled with the DCASL dry dynamical core. The Jablownoski–Williamson test is used to carry out baroclinic instability simulations for five cases with the same initialization but different CO
Hurricanes accelerate dissolved organic carbon cycling in coastal ecosystems
Authors: Yan Ge , Labonté Jessica , Quigg Antonietta , Kaiser Karl
Published: March 2020

Extreme weather events such as tropical storms and hurricanes deliver large amounts of
freshwater (stormwater and river discharge) and associated dissolved organic carbon (DOC)
to estuaries and the coastal ocean, affecting water quality and carbon budgets. Hurricane
Harvey produced an unprecedented 1000-year flood event in 2017 that inundated the heavily
urbanized and industrialized Houston/Galveston region (Texas, USA). Within a week, storm-
associated floodwater delivered 105±10 Gg of terrigenous dissolved organic carbon (tDOC)
to Galveston Bay and the Gulf of Mexico continental shelves. In-situ decay constants of
8.75-28.33 yr -1 resulted in the biomineralization of ~70% of tDOC within one month of
discharge from the flood plain. The high removal efficiency of tDOC was linked to a diverse
microbial community capable of degrading a wide repertoire of dissolved organic matter
(DOM), and suggested hurricane-induced flood events affect net CO2 exchange and nutrient
budgets in estuarine watersheds and coastal seas.
Groundwater dependent forest and wet meadow characteristics in a changing climate
Authors: Nevezi Csenge , Bazsó Tamás , Csáki Péter , Kalicz Péter , Zagyvai-Kiss Katalin Anita , Gribovszki Zoltán
Published: March 2020

Eco-hydrology of hydrophyte forests and wet meadows are very important question in changing climate. Hydrological extremes can cause in these habitats droughts, intense rainfall events and floods. In this study, we investigated a riparian alder forest and its edge, and a neighbouring meadow in Hidegvíz Valley experimental catchment to compare different surface cover type hydrological and botanical characteristics. The research has conducted in 2018-2019 hydrological year.
Throughout the botanical study, a list has been made of the various plant species – trees, bushes, and herbs - of the elder woodland and its edge, and the grassland, in each vegetation period. The classifications of the habitats were made by the Á-NÉR system, which is a Hungarian classification system for Hungarian habitats.
The hydrological research was focused on three important factors in the one-year period: precipitation, the changes of the groundwater levels, and the soil moisture values. We summarised the monthly data, and from all this, we calculated an annual water balance graph. This graph showed us a correlation between hydrological extremes and soil moisture value changes.
The research was supported by the “EFOP-3.6.1-16-2016-00018 – Improving the role of research+development+innovation in the higher education through institutional developments assisting intelligent specialization in Sopron and Szombathely” project.
The Spacecraft Potential’s Influence on the FOV of Rosetta-ICA at Low Ion Energies
Authors: Bergman Sofia , Stenberg Wieser Gabriella , Wieser Martin , Johansson Fredrik , Eriksson Anders
Published: March 2020

Low-energy ions play important roles in many processes in the environments around various bodies in the solar system. At comets, they are, for example, important for the understanding of the interaction of the cometary particles with the solar wind, including the formation of the diamagnetic cavity.

Unfortunately, spacecraft charging makes low-energy ions difficult to measure using in-situ techniques. The charged spacecraft surface will attract or repel the ions prior to detection, affecting both their trajectories and energy. The affected trajectories will change the effective FOV of the instrument. A negatively charged spacecraft will focus incoming positive ions, enlarging and distorting the FOV.

We model the low-energy FOV distortion of the Ion Composition Analyzer (ICA) on board Rosetta. ICA is an ion spectrometer measuring positive ions with an energy range of a few eV to 40 keV. Rosetta was commonly charged to a negative potential throughout the mission, and consequently the positive ions were accelerated towards the spacecraft before detection. This distorted the low-energy part of the data. We use the Spacecraft Plasma Interaction Software (SPIS) to simulate the environment around the spacecraft and backtrace particles from the instrument. We then compare the travel direction of the ions at detection and infinity, and draw conclusions about the resulting FOV distortion. We investigate the distortion for different spacecraft potentials and Debye lengths of the surrounding plasma.

 The results show that the effective FOV of ICA is severely distorted at low energies, but the distortion varies between different viewing directions of the instrument. It is furthermore sensitive to changes in the Debye length and we observe a small non-linearity in the relation between FOV distortion, ion energy and spacecraft potential. Generally, the FOV is not significantly affected when the energy of the ions is above twice the spacecraft potential.
Simple and spatialize approach to optimize irrigation water and wheat yield in the semi-arid areas
Authors: Khabba Said , Toumi Jihad , Er-Raki Salah , Ezzahar Jamal , Le Page Michel , Chehbouni Abdelghani , Jarlan Lionel
Published: March 2020

In this study, we developed a simple and spatialized wheat yield method based on the Monteith's three efficiency model. The originality of the method consists in: (1) the expression of the conversion coefficient (εconv) by considering an appropriate stress threshold (ksconv) for triggering irrigation, (2) the substitution of the product of the two maximum coefficients of interception (εimax) and conversion (εconv_max) by a single parameter εmax, (3) the modeling of εmax as a function of the Cumulative Growing Degree Days (CGDD) since sowing date, and (4) the dynamic expression of the harvest index HI as a function of the CGDD and the final harvest index HI0 depending of the maximum values of the Normalized Difference Vegetation Index (NDVI).

The calibration and validation of the proposed model were performed by using observed dry matter (DM) and grain yield (GY) on wheat conducted on the irrigated zone R3 of the Haouz plain (center of Morocco), during three agricultural seasons 2002/2003, 2008/2009 and 2012/2013. The model calibration allowed the parameterization of εmax in four periods according to the wheat phenological stages. By contrast, a linear evolution was sufficient to represent the relationship between HI and CGDD. The model validation was performed at the field and regional scales. For the field scale, the obtained results showed a good agreement between the estimated and observed values of DM and GY with Root Mean Square Error (RMSE) of about 1.07 t/ha and 0.57 t/ha for DM and GY, respectively. Likewise, at the regional scale, the proposed approach was tested over the irrigated district (R3) by using Landsat/spot images for mapping GY and DM. The RMSE values were 1.21 t/ha and 0.34 t/ha between measured and simulated DM and GY, respectively.
Fault interaction and strain partitioning in southeastern Tibetan Plateau: from kinematics to geodynamics
Authors: Yin Li
Published: March 2020

In southeastern Tibetan Plateau, the Xianshuihe-Xiaojiang fault system (XXFS) and its neighboring fault systems collectively accommodates the material extrusion of the Tibetan Plateau. However we do not mechanically understand how these faults interact with each other and how the fault interaction impacts strain partitioning, fault slip rates, and seismicity in this region. We develop and use a three-dimensional viscoelastoplastic finite element model to simulate regional deformation, fault slip rates, and fault interaction in the fault system of southeastern Tibetan Plateau. We investigate the effects of inception and activity of faults, fault strength, lithospheric rheology, and topography on partitioning of strain and fault slip rates. Model results show that fault strength, lithospheric rheology, and topography all significantly influence the strain partitioning and slip rates on faults. The initiation of the Daliangshan fault results mainly from the non-smooth fault geometry of the main trace of the XXFS. Our model results support the hypothesis of codependent slip rate between fault systems. For the present fault configuration, our model predicts localized strain in the Daliangshan faults, Yingjing-Mabian faults, and Lianfeng-Zhaotong faults, where numerous earthquakes occurred in recent years.