bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-scale Food- Energy-Water Nexus to link national, regional and local sustainability based on resource-sheds and system dynamics modeling: A Case study of Japan
Authors: Lee Sanghyun , Taniguchi Makoto , Masuhara Naoki
Published: March 2020

The aim of this study is to develop a Food-Energy-Water (FEW) Nexus platform based on boundaries of resources and system dynamics modeling. For example, water-shed indicates river basin, aquifer or water supply area regarded as non-tradable boundary. However food-shed indicates both food production and consumption area in addition to food trade. Energy-shed is mainly defined by electricity distribution. Therefore, the boundary of each resource is different and we link water, energy, and food boundaries such as resource-sheds in the FEW Nexus.  As a case study, we analyze the interlinkage among national, regional, and local sustainability in terms of resource management and socio-economic-environmental impacts in Japan. First, we analyze the local characteristics of FEW Nexus as a prefecture level using the FEW indices, and assess the potential issues under future industrialization or economic growth situations. Second, we combine the local FEW Nexus into regional platform, for example, the Kansai regional Nexus including Osaka, Kyoto, Shiga, Hyogo, Nara, and Wakayama prefecutures. Finally, we adpat the boundary of resource-sheds into the regional Nexus and assess the changes in local resource management on regional resource sustainability using system dynamics modeling. Thus, we assess the impacts of changes about water, energy, and food management in each prefecture on regional water and energy security in Kansai region. This study could contribute to develop a common framework for scientists and policy-makers to evaluate sustainable resource management with multi-scale perspective, thus it has the potential to achieve integrated water, energy and food security.
Strong atmospheric surface pressure anomalies drive a see-saw in Subantarctic Mode Water formation
Authors: Cerovecki Ivana , Meijers Andrew
Published: March 2020

The dominant Subantarctic Mode Water (SAMW) formation regions are located in the Indian, and in the Pacific sector of the Southern Ocean. Strong wintertime (Jul-Sep) surface air pressure anomalies with variance maxima at approximately 100°E and 150°W drive a zonal dipole structure in the SAMW formation and thickness, in both the Indian and Pacific sector of the Southern Ocean. This has been documented within gridded Argo data for years 2005-2019. A much weaker surface air pressure anomaly variance maxima is located in the Atlantic Ocean centered at approximately 25°W.

Anomalously strong positive pressure anomalies result in deepening of the wintertime mixed layers and an increase in the SAMW formation in the eastern part of the Pacific and Indian sector; these effects are due to cold southerly winds, strengthened zonal winds and increased surface ocean heat loss. 
Anomalously strong negative pressure anomalies result in shoaling of the wintertime mixed layers and a decrease in SAMW formation in these regions, while at the same time deepening the wintertime mixed layers and increasing SAMW formation in the western Indian Ocean and in the central Pacific.

In years with strong El Nino, the interannual variability of the strength of two surface air pressure anomalies does not co-vary in phase with each other. Strong isopycnal heave in SAMW density range emanates from locations where winter surface air pressure anomalies and mixed layers are most strongly coupled.  
Lidar-based Water Vapor, Temperature and Wind Measurements with Turbulence Resolution during the EUREC4A Field Campaign onboard RV Merian
Authors: Lange Vega Diego , Behrendt Andreas , Späth Florian , Wulfmeyer Volker
Published: March 2020

The EUREC4A (ElUcidating the RolE of Clouds-Circulation Coupling in Climate) field campaign takes place in the lower Atlantic trades, over the ocean east of Barbados from 20 January to 20 February 2020. During this campaign, for the first time, simultaneous measurements of surface turbulence, cloud microphysical properties, cloud radiative properties, convective activity and the large-scale environment in which clouds and convection are embedded (large-scale vertical motion, thermodynamic stratification, surface properties, turbulent and radiative sources or sinks of energy).

Our new Atmospheric Raman Temperature and Humidity Sounder (ARTHUS) observes temperature and moisture profiles over the ocean with turbulence resolution of up to 10 s and 7.5 m. By this, the thermodynamic properties as well as statistics of their turbulent fluctuations in the oceanic boundary layer can be investigated in detail including relative humidity, buoyancy, CAPE, and CIN. In addition, ARTHUS is also a aerosol Raman lidar and provides profiles of particle extinction and backscatter coefficient independently at 355 nm. Two Doppler lidars – one vertical pointing the second in scanning mode – measure horizontal wind profiles as well as profiles of vertical wind fluctuations, turbulent kinetic energy, and momentum flux. The combination of the three lidars will provide synergetic data products like latent and sensible heat flux profiles. Thus, this combination allows to investigate boundary-layer properties including cloud formation and aerosol-cloud interaction.

During the EGU General Assembly, we will show our first results from the campaign.
Effect of Drought and Recovery on Microbial, Fungal, and Crop Response in a Diverse Multi-Crop Rotation
Authors: Senturklu Songul , Landblom Douglas , Steffan Joshua
Published: March 2020

Soil nutrient availability is essential for adequate crop production and drought conditions that result in abnormally low amounts of precipitation for extended periods of time have a substantial impact on soil microbial activity and therefore nutrient cycling. The northern Great Plains region of the USA suffered an extended period of time in which effective precipitation for crop production was severely reduced and based on the USA Drought Monitor the drought during the growing season from April through October 2017 was classified as exceptional drought. At the NDSU – Dickinson Research Extension Center, a long-term integrated system that includes a diverse multi-crop rotation (spring wheat, cover crop, corn, pea-barley intercrop, and sunflower), beef cattle grazing of the pea-barley, corn, and a 13-specie cover crop within the rotation, is being utilized to monitor the effects soil microbial and fungal activity have on production over time and space in this crop and animal production system. Moreover, the overall effects of increased soil health indices on production are being monitored. Research results have previously been reported showing that soil organic matter (SOM) mineralization has resulted in reduced nitrogen fertilizer application. Regression analysis of SOM and potential nitrogen mineralization suggests that 8.4 mg N/kg are mineralized for each 1% increase in SOM. However, during periods of restricted precipitation on rain-fed crops, soil microbial respiration and fungal activity are negatively impacted, and crop production and animal grazing days are sharply reduced. Soil microbial biomass was correlated to overall production with the exception of spring wheat in rotation which may be due to increased water use by the previous crop (sunflower). Further analysis indicated that most soil microbial organisms recovered two years post drought with the exception of Rhizobia spp. populations which did not recover two years post drought. However, compared to the pre-drought 2016 production year, overall crop production yields had not fully recovered by 2019. Compared to the 2016 crop production, overall crop production in the rotation was reduced 64% in 2017, recovered to 54% of 2016 in 2018, and recovered to 66% of 2016 by the 2019 crop year. Whether crop yields are on par with 2016 by the end of the 2020 crop year is still to be determined. These yield observations point to the amount of time needed to fully recover from the long-term effects of exceptional drought on crop production.
Geomagnetic Field Paleointensity during the Cretaceous Normal Superchron from Marine Magnetic Anomalies
Authors: Li Yuanjie , Liu Qingsong
Published: March 2020

The knowledge of the geomagnetic field intensity during the Cretaceous Normal Superchron, a long term of forty million years without polarity reversals, may have a large impact on our understanding of the dynamo process occurring in Earth’s outer core. How, it is difficult to get the geomagnetic field behavior during the Cretaceous Normal Superchron resulting from the inadequate sampling or data of variable qualities from igneous rocks and sedimentary. Here we examine 20 magnetic anomaly profiles across the Cretaceous magnetic quiet zone of the Central Atlantic Ocean in the African flank extracted from the EMAG2v3, and calculate a synthetical magnetization profile based on the forward modeling method. We suggest that this profile records the high strength of geomagnetic field at the beginning of ~30 million years and low signal during the late period, which could be correlated with the low-resolution relative paleointensity record from the sediment samples at the Falkland Plateau, and which also could be found the VDMs/VADMs averaged by a 7-Ma sliding window from the absolute intensity records mostly from the MagIC database. Our results support the hypothesis that the distribution of heat flow along the core-mantle boundary is positively correlative to the intensity of the dipole field.
Compact Operational Tropospheric Water Vapor and Temperature Raman Lidar with Turbulence Resolution
Authors: Lange Vega Diego , Behrendt Andreas , Wulfmeyer Volker
Published: March 2020

Here we present the new Atmospheric Raman Temperature and Humidity Sounder (ARTHUS), an exceptional tool for observations in the atmospheric boundary layer during daytime and nighttime with a very short latency. ARTHUS measurements resolve the strength of the inversion layer at the planetary boundary layer top, elevated lids in the free troposphere during daytime and nighttime, and turbulent fluctuations in water vapor and temperature, simultaneously, also during daytime.

The observation of atmospheric moisture and temperature profiles is essential for the understanding and prediction of earth system processes. These are fundamental components of the global and regional energy and water cycles, they determine the radiative transfer through the atmosphere, and are critical for the clouds formation and precipitation. Also, it is expected that the assimilation of high-quality, lower tropospheric WV and T profiles will result in a considerable improvement of the skill of weather forecast models particularly with respect to extreme events.

Very stable and reliable performance was demonstrably achieved during more than 2500 hours of operations time experiencing a huge variety of weather conditions. ARTHUS provides temperature profiles with resolutions of 10-60 s and 7.5-100 m vertically in the lower free troposphere. During daytime, the statistical uncertainty of the WV mixing ratio is <2 % in the lower troposphere for resolutions of 5 minutes and 100 m. Temperature statistical uncertainty is <0.5 K even up to the middle troposphere. ARTHUS fulfills the stringent WMO breakthrough requirements on nowcasting and very short-range forecasting.

This performance serves very well the next generation of very fast rapid-update-cycle data assimilation systems. Ground-based stations and networks can be set up or extended for climate monitoring, verification of weather, climate and earth system models, data assimilation for improving weather forecasts.
Establishment a planning of disaster mitigation facilities by the impact of large-scale artificial structures on mountain slope
Authors: Kim Man-Il , Kwak Jaehwan , Kim Namgyun
Published: March 2020

The forest development has consistently increased that Korea is composed of almost 64% mountain area. The large-scale facilities, like a wind power system foundation, are planned along the top of mountain. As installation of the large-scale facilities, there is a potential risk in the mountain area like landslide, debris flow and so on. Therefore, we has performed some assessments to slopes and streams at mountain areas and roads of a wind power system foundation, which is being a large-scale change topography (1. Risk assessment using GIS analysis and design data, 2. Basic investigation research and detailed investigation research based on a standard from authorities, 3. Vulnerability analysis using a numerical analysis and a quantitative criteria). As a result, we are able to investigate a primary cause for a mountain disaster risk, and establish a planning of disaster mitigation facilities, which are consistent with a local and a geographical characteristic, for the mountain area involved potential risk.
Breaking the temporal barrier in air quality monitoring over Europe with Sentinel-4
Authors: Loyola Diego , Aspetsberger Michael , Dubovik Oleg , Fantin Daniele , Govaerts Yves , Richter Andreas , Van Roozendael Michel , Siddans Richard , Veefkind Pepijn , Veihelmann Ben , Wagner Thomas , Wright Norrie
Published: March 2020

European UVN satellite missions deliver global measurements for air quality and climate applications from Low Earth Orbit (LEO) satellites since over two decades. Currently we have in the morning data from GOME-2 on the three MetOp satellites and in the early afternoon data from OMI/Aura and TROPOMI/Sentinel-5 Precursor.

The temporal barrier imposed by LEO satellites, providing only one daily observation, can be broken using Geostationary Equatorial Orbit (GEO) satellites. The Sentinel-4 (S4) mission on-board the MTG-S GEO satellite will focus on monitoring of trace gas column densities and aerosols over Europe with an hourly revisit time, thereby covering the diurnal variation of atmospheric constituents.

We present the algorithm, verification, and processor work being performed as part of the ESA Sentinel-4 Level 2 (S4-L2) project responsible for developing the operational S4-L2 products: O3 total and tropospheric column, NO2 total and tropospheric column, SO2, HCHO, CHOCHO columns, aerosol and cloud properties as well as surface reflectance.

 
Modeled acoustic propagation through a measured large-amplitude nonlinear internal wave in northern South China Sea
Authors: Qi Peng
Published: March 2020

Preliminary results are presented from an analysis of modeled mid-frequency sound propagation through a measured large-amplitude nonlinear internal solitary wave, and in-situ measurements of trains of nonlinear internal waves in northern South China Sea (SCS) as well. An acoustic propagation model based on ray theory was utilized to compute the transmission loss (TL) associated with passing the large depression measured internal waves. The TL was computed using the model considering (1) range-dependent and range-independent environmental scenario and (2) for different source and receiver depth configurations. This presentation will propose several interesting aspects of influence of internal waves on acoustic propagation, including "shadow zones", with or without eddy, etc.
High-resolution seismic reflection profiling of the active fold-and-thrust systems in the Shonai backarc basin, northern Honshu, Japan
Authors: Kato Naoko , Sato Hiroshi , Ishiyama Tatsuya
Published: March 2020

Northern Honshu, Japan, forms a classical example of the trench-arc-backarc basin system. Along the coast of the Sea of Japan, Miocene aborted rifts were developed filled with thick Neogene sediments and form an active fold-and-thrust belt. Devastative crustal earthquakes, such as the Shonai earthquake 1894 (M7), occurs historically. To reveal the relationship between active fault and fold structure with seismogenic source faults is significant for the evaluation of seismic hazards and possible risk. In the Shonai plain, northern Honshu, we performed 2D high-resolution seismic reflection profiling across the active faults. Seismic data was collected by 10 m shot and receiver interval using Enviro vib and Minivib (IVI) to obtain high-resolution image. Along some of the seismic lines, seismic reflection survey was recorded by fixed 800-1000 channels, producing high number of folds. The resultant seismic profiles provide the image of a fold-and-thrust belt developed in the Miocene volcanic rift basin. Former syn-rift faults reactivated as reverse faults and thin-skinned deformation prevails in the post rift sediments forming detachment in the Miocene over pressured mudstone units. Fault-related folds and wedge thrusting is common feature of the shortening deformation. There are two active thrust systems in the Shonai basin. One is known active fault system along the eastern margin of the Shonai plain and the other is an active-blind - thrust located in the central part of the basin. The late Quaternary tectonic movements along this fault was confirmed by the high-resolution seismic profiling. 
Organic pore structure characterization of shale: a comparison between scanning electron microscopy and helium ion microscopy
Authors: Zhao Junliang , Zhang Wei , Zhang Dongxiao
Published: March 2020

Scanning electron microscopy (SEM) and helium ion microscopy (HIM) are two of the fundamental tools in the study of the microstructures of shale. A comprehensive comparison of these two techniques in the application of organic pore structure characterization is presented in this work. Owing to the small wavelength of the helium ion, the spot size of the ion beam is not restricted by diffraction aberration, and the convergence angle of helium ion beam can be much smaller than of the electron beam. The microscopic images and reconstruction models indicate that HIM has higher spatial resolution and increased depth of field than SEM. The pores below 10 nm and inner structures of pore networks can be observed via HIM images. The advantages shown in the focused ion beam/helium ion microscopy (FIB/HIM) results are similar to the 2-D HIM images. Smaller pores whose size is beyond the resolution of focused ion beam/scanning electron microscopy (FIB/SEM) can be found, which suggests the connection possibility of the big pores. However, to get reliable pictures, the ion-induced damage on organic matters should be avoided. To lower the beam current and to shorten the dwell time are two effective ways to reduce the beam damage.
Spatiotemporal characteristics of water budget dynamic in the Yarlung Tsangpo River basin of Tibetan Plateau based on multi-source datasets
Authors: Jiang Yao , Xu Zongxue
Published: March 2020

Understanding the dynamics of basin-scale water budgets over the Tibetan Plateau (TP) is significant for hydrology and water resource management in the southern and eastern Asia. However, a detailed water balance analysis is limited by the lack of adequate hydro-climatic observations in this region. In this study, we investigate the spatiotemporal variation of water budget components (e.g. precipitation P, evapotranspiration ET and runoff Q etc.) in the Yarlung Tsangpo River basin (YTB) of southeast TP during the period of 1975-2015 through using multi-source datasets (e.g. insitu observation, remote sensing data products, reanalysis outputs and model simulations etc.). The change trend of water budget components and vegetation parameters was analyzed in the YTB on interannual scale. The results indicated that the detailed water budgets are different from upstream to downstream YTB due to different temperature, vegetation cover and evapotranspiration, which are mainly affected by different climate conditions. In the whole basin, precipitation that are mainly during June to October was the major contributor to the runoff. The P and Q were found to show a slight but insignificant decrease in most regions of YTB since the late 1990s, which showed positive relationships with the weakening Indian summer monsoon. While the ET showed an insignificant increase across most of the YTB, especially in the middle basin. The runoff coefficient (Q/P) exhibited an indistinctively decreasing trend which may be, to some extent, due to the overlap effects of ET increase and snow and glacier changes. The obtained results offer insights into understanding the evolution mechanism of hydrological processes in such a data-sparse region under changing environment.
A two-stage surrogate model based on ANN and AdaBoost for multi-objective parameter optimization of the Variable Infiltration Capacity model
Authors: Xu Yue-Ping , Gu Haiting , Di Ma
Published: March 2020

Distributed hydrologic models have been widely used for its functional diversity and rationality in theory. However, calibration of distributed models is computationally expensive with a large number of model runs, even if an efficient multi-objective algorithm is employed. To alleviate the burden of computation, we develop a two-stage surrogate model by coupling backpropagation neural network with AdaBoost to calibrate the parameters of the Variable Infiltration Capacity (VIC) model. The first stage model selects the parameter sets with simulated outputs in the crucial range and the second stage model estimates the values of outputs accurately with the parameter sets picked out by the first stage model. The developed surrogate model is tested in three different river basins in China, namely the Lanjiang River basin (LJR), the Xiangjiang River basin (XJR) and the Upper Brahmaputra River basin (UBR). With sufficient samples generated by ε-NSGA II, the surrogate model performs very well with a low error rate of classification (ER) and root mean square error (RMSE). The streamflow simulated with the surrogate model is nearly the same as that from the original VIC model, indicating that the surrogate model does gain a remarkable speedup compared with the original VIC model.
Data assimilation of subsurface flow via iterative ensemble smoother and physics-informed neural network
Authors: Wang Nanzhe , Chang Haibin
Published: March 2020

Subsurface flow problems usually involve some degree of uncertainty. For reducing the uncertainty of subsurface flow prediction, data assimilation is usually necessary. Data assimilation is time consuming. In order to improve the efficiency of data assimilation, surrogate model of subsurface flow problem may be utilized. In this work, a physics-informed neural network (PINN) based surrogate model is proposed for subsurface flow with uncertain model parameters. Training data generated by solving stochastic partial differential equations (SPDEs) are utilized to train the neural network. Besides the data mismatch term, the term that incorporates physics laws is added in the loss function. The trained neural network can predict the solutions of the subsurface flow problem with new stochastic parameters, which can serve as a surrogate for approximating the relationship between model output and model input. By incorporating physics laws, PINN can achieve high accuracy. Then an iterative ensemble smoother (ES) is introduced to implement the data assimilation task based on the PINN surrogate. Several subsurface flow cases are designed to test the performance of the proposed paradigm. The results show that the PINN surrogate can significantly improve the efficiency of data assimilation task while maintaining a high accuracy.
Three dimensional crustal Vp structure beneath the Pearl River Estuary from joint onshore-offshore seismic experiment
Authors: Wang Liwei , Ye Xiuwei , Wang Xiaona , Lv Zuoyong , Zhang Yunpeng , Wang Baoshan
Published: March 2020

The Pear River Estuary (PRE) area is located in the northern margin of South China Sea (SCS), which is a typical rifted passive continental margin between the South China Block and SCS Basin. The Littoral Fault Zone (LFZ) crossing the PRE is an important seismogenic and boundary fault. Strong earthquakes occurred in both the west and east segments. While, the middle segment of the LFZ in PRE area is lack of large earthquake and possibly a seismic gap. Imaging the fine structure of the PRE area is helpful to understand the background of the spatial heterogeneity of seismicity. To explore the crustal structure of the PRE area, we carried an active-source experiment in July 2015. During the experiment, an airgun array composed of four individual airguns with total volume of 6000 in3 mounted on SCSIO’s R/V Shiyan II was used as the seismic source. A total of 12200 shots were fired every 300 meters along 10 NW and 3 NE-trending shooting profiles. Six dynamite sources with a charge range from 1000 to 2500 kg were also shot on the land. During the experiment, 431 receivers including 29 ocean bottom seismographs (OBS), 256 short period seismometers, and 146 broadband seismometers were available. We manually picked Pg arrivals from the airgun and dynamite sources. We calculated a minimum 1D velocity model by VELEST. We then obtained the upper crust Vp structure using three-dimensional seismic tomography. Our preliminary result reveals that the Vp is consistent with local geological settings. There are low velocity anomaly beneath the LFZ and obvious velocity anomalies across the NW- and NE-trending active faults, which maybe potential threat to the Greater Bay Area.
A new approach to HDO/H2O ratio profile retrieval in the atmosphere from TANSO-FTS/GOSAT-2 spectrum data by using TIR and SWIR spectral ranges simultaneously: method and software
Authors: Ilya Zadvornykh , Konstantin Gribanov , Vyacheslav Zakharov , Nina Denisova , Ryoichi Imasu , Martin Werner
Published: March 2020

Global monitoring of isotopic composition of water vapor in the atmosphere provides information regarding atmospheric hydgrological cycle in the Earth’s climate system. The observed HDO to H2O ratio (δD) in atmospheric water vapor gives information on origin and history of air masses in the atmosphere.

In this study we present a method, software tool and some results on δD ratio retrieval from spectra, measured simultaneously in the thermal (TIR) and short wave infrared (SWIR) spectral ranges. The TANSO-FTS high spectral resolution spectrometer on board GOSAT-2 satellite is unique to perform simultaneous measurements in TIR and SWIR spectral bands. A method of simultaneous using of these both bands can improve vertical resolution of δD retrieved profile.

We applied conventional optimal estimation method to solve inverse problem. The output data of atmospheric general circulation model ECHAM5-wiso were used as a statistical ensemble of HDO and H2O a priori profiles. The averaging kernels, a posteriori covariance matrices and degrees of freedom are calculated. The retrieval algorithm is implemented using original FIRE-ARMS software and VLIDORT radiation transfer model.

This study is supported by the Russian Science Foundation grant No. 18-11-00024.
Constrained Surface-wave Dispersion Inversion Using GPR Reflection Data
Authors: Hu Shufan , Zhao Yonghui , Bi Wenda , Shen Ruiqing , Li Bo , Ge Shuangcheng
Published: March 2020

Ground penetrating radar (GPR) and Seismic Surface Wave methods (SWMs) are two nondestructive testing (NDT) methods commonly used in near-surface site investigations. These two methods investigate the media properties of subsurface based on different physical phenomena. GPR has a good resolvability to characterize the layered structure since the propagation of electromagnetic wave is sensitive to the change of electrical properties, while, the geometric dispersion of surface waves can be used to retrieve the variation of S-wave velocity (Vs) with depth. In most situations, these two data sets are processed separately, and the results are later used for comprehensive interpretation. Constrained inversion, as a way to implement data fusion, can alleviate the non-uniqueness of the solution and produce more consistent information for the comprehensive site and material investigations.

We present an algorithm for the inversion of surface-wave dispersion curves with GPR interface constraints in 2D media. The reflection interfaces interpreted from the GPR profile are integrated into a cell- and boundary-based Vs model. This implementation allows both vertical and lateral changes within each region while also allows sharp changes across the boundaries. In addition, our algorithm simultaneously inverts several dispersion curves extracted along the survey line using multi-size spatial windows, which mitigates the adverse effects of 1D assumption in traditional surface-wave dispersion inversion and improves the matching of GPR and SWMs in lateral variations. We use synthetic and field data sets to test the effectivity of the proposed method. Both results show the improved resolution of the Vs model retrieved by the constrained inversion compared to the standard inversion.
Current status, initial results, and updated plans of BepiColombo/Mio: interplanetary cruise and planetary flybys
Authors: Murakami Go , Benkhoff Johannes , Hayakawa Hajime
Published: March 2020

The ESA-JAXA joint mission BepiColombo is now on the track to Mercury. Two spacecraft for BepiColombo, "Mio" (Mercury Magnetospheric Orbiter: MMO) and "Bepi" (Mercury Planetary Orbiter: MPO), were successfully launched by Ariane-5 launch vehicle from Kourou in French Guiana on 20 October 2018. Mio is fully dedicated to investigating Mercury’s environment with a complete package of plasma instruments (particles, electric fields, and magnetic fields), a spectral imager of sodium exosphere, and a dust monitor. During the cruise to Mercury, in addition to two spacecraft MMO Sunshield and Interface Structure (MOSIF) and Mercury Transfer Module (MTM) are all integrated together. After the commissioning operations of spacecraft, we are focusing on preparing science operations for interplanetary cruise and planetary flybys. Some science instruments can be used even in the composite spacecraft configuration. The first and second flybys will happen at the Earth in April 2019 and at Venus in October 2019, respectively. In addition, during the interplanetary cruise BepiColombo can contribute to inner heliospheric science by measuring the solar wind and solar energetic particles. Thanks to NASA’s Parker Solar Probe and ESA’s Solar Orbiter, multi-spacecraft observations of the inner heliosphere will soon be possible and provide us deeper knowledge of this region. Here we report the updated status of BepiColombo mission, initial results of the commissioning operations, and the future plans for interplanetary cruise and planetary flybys.
Earthquake-based Full-Waveform Inversion at the Exploration Scale from Dense Broadband Array Data
Authors: Liu Qiancheng , Simons Frederik , Gao Fuchun , Williamson Paul , Tromp Jeroen
Published: March 2020

In challenging environments with natural seismicity and where active source acquisition is expensive and dangerous, the question arises whether naturally occurring earthquakes offer useful information for hydrocarbon exploration. Here, we report on an experiment that installed 252/247 receivers to acquire data for two periods of 7 months, in the presence of significant rugged topography (elevations from 500 m to 3500 m). The station density is about 1 per 25 km^2 (compared to, e.g., USArray, where the average station spacing was 70 km). Data were recorded in a frequency band from 0.2 Hz to 50 Hz. Several thousand seismic events originating within the array bounds were identified in these data. A compressional-speed tomographic velocity model was derived using first-arriving phases. Centroid moment tensor (CMT) solutions have been obtained for about 4% of the identified events using Green’s function-based multicomponent waveform inversion, assuming a layered velocity model. We are now working to improve that model by performing elastic full-waveform inversion for three-dimensional compressional and shear-wave speed perturbations, honoring the topography, after a prior full-wavefield-based reassessment of the earthquake source mechanisms. We are also aiming to increase the number of events considered in the inversion while weighting the data based on estimates of data quality. This is assessed with a flexible automated procedure that considers a variety of data attributes over a range of frequencies. We run simulations using the spectral-element package SPECFEM3D on a cluster that employs 4 GPU cards per simulation. We identify the promising areas of good initial fit from the highest-quality seismic traces and gradually bring the predictions in line with the observations via LBFGS model optimization. We review the results of our work so far, discuss how to continue to bring best practices from global seismology down to the regional scale, and consider the implications for using such passive experiments to complement or replace active exploration in such challenging zones.
Evaluation of the numerical wave model (WaveWatch III) for wave simulation in the Antarctic marginal ice zone
Authors: H. Derkani Marzieh , Hessner Katrin , Zieger Stefan , Nelli Filippo , Alberello Alberto , Toffoli Alessandro
Published: March 2020

The Southern Ocean is the birthplace of the fiercest waves on the Earth, which play a fundamental role in global climate by regulating momentum, heat and gas exchanges between the atmosphere and ocean. At high latitudes, waves interact with Antarctic sea ice, another crucial player of the Earth's climate system, modulating its expansion in the winter and its retreat in summer and hence affecting the global albedo. Despite the impact of waves on climate, global wave models are considerably biased in the Southern Hemisphere, due to the scarcity of observations in these remote waters. This is exacerbated in the marginal ice zone, the region of ice-covered water between the compact ice or land and the open ocean, where surface waves, upper ocean and atmosphere interact with sea ice but the dominant physics are still largely unknown. To improve our understanding of physical processes in Southern Ocean and model capabilities, the Antarctic Circumnavigation Expedition (ACE) sailed these waters from December 2016 to March 2017 to acquire wave data (among other climate variables) both in the open ocean and Antarctic marginal ice zone. Observations were gathered using a radar-based wave and surface current monitoring system (WaMoS-II) built on board of the research icebreaker Akademik Tryoshnikov. Here, we discuss how these observations underpin the set up, calibration and validation of the WaveWatch III wave model over a domain covering the entire Southern Hemisphere, therefore spanning from tropical waters to the edge of sea ice (open waters only). The calibrated model will then be used to carry out a thorough assessment of different sea ice modules, to evaluate accuracy of predictions in the marginal ice zone. Test cases of waves-in-ice recorded during the Antarctic Circumnavigation Expeditions will be discussed in details.
Design of an optimal seismic network for monitoring geothermal fields
Authors: Esquivel Mendiola Leonarda Isabel , Calò Marco , Tramelli Anna
Published: March 2020

The reliable monitoring and location of the seismic activity at a local and regional scale is a key factor for hazard assessment. The exploitation of a geothermal field can be affected by natural and induced seismicity, hence optimal planning of a seismic network is of great interest for geothermal development.
Seismic monitoring depends on two main aspects: i) sensitivity of the seismic network and ii) the effectiveness of detection and location methods.
In this study, we focus on the first aspect proposing and improvement of an algorithm for the optimization of seismic networks designed for monitoring the seismic activity related to the injection test that will be performed in a geothermal well.
The algorithm is based on the method proposed by Tramelli et al. (2013) that tries to find the optimal station positions minimizing the volume of the error ellipsoid of the location for synthetic events using the D-criterion (Rabinowitz and Steinberg, 2000).
In this version of the program we improve the algorithm to find an optimal seismic network considering several prior information such as: 1) maps of seismic noise levels at different frequency bands, 2) three-dimensional seismic models and 3) topographic gradient of the study region. This information is usually produced during the exploration stage of a geothermal site and available prior an injection test.
We applied the methodology to the Acoculco geothermal field (Mexico) where an injection test is planned. In this work, we show a comparison between the standard approach that uses 1D seismic models, constant values of noise levels, and no topographic effects, with the new one showing how important is to consider these parameters for a more suitable optimization of the seismic network.
This work is performed in the framework of the Mexican European consortium GeMex (Cooperation in Geothermal energy research Europe-Mexico, PT5.2 N: 267084 funded by CONACyT-SENER : S0019, 2015-04, and of the joint agreement between UNAM and INGV on the development of seismological research of volcanic and geothermal field (N:44753-1023-22-IV-16/1).
Landslide Susceptibility Assessment Considering Imbalanced Data: Comparison of Random Forest and Multi-Layer Perceptron
Authors: Lee JungHyun , Park HyuckJin , Lee DongJun , Lim SooHyeon
Published: March 2020

The landslide prediction analyzes the various landslides related factors and their correlations physically or mathematically. Many researches used statistical methods to consider the relationships between landslide occurrence location and related factors such as topography, and geology. Existing statistical methods produces errors due to the variety and uncertainty of the input data. Recently, machine learning techniques using artificial intelligence and big data is proposed to improve the accuracy and efficiency of landslide prediction and management. Landslide is caused by the nonlinear relationships of potential related factors and the effects of triggered factors such as meteorological or man-made damage. This study proposes a better performance of the prediction results by using machine learning model that is suitable for considering the nonlinear correlation of related factors.
Generally, landslides occur in very small numbers in widely study areas. In order to construct a predictive model using machine learning, the information about the landslide occurrence location and the non-landslide occurrence location must be used. However, all the study area data is used, the landslide prediction results are not reliable because they are mainly affected by the information about the non-landslides. Therefore, to minimize over-fitting or under-fitting due to data imbalance, the appropriate sampling rate of landslide and non-landslide data should be considered.
In this study, landslide prediction was performed using a machine learning models Random Forest (RF) and Multi-Layer Perceptron (MLP). RF builds multiple decision trees and merges them together to get a more accurate and stable prediction. RF model can be obtained variable importance which variables have the most predictive power. This value is used to identify the characteristics of related factors and to select the related factors to be used for landslide predicts. MLP is feedforward neural network with one or more layers between input and output layer. This model consists of at least three layers of nodes and each node is a neuron that uses a nonlinear activation function. So, it can distinguish data that is not linearly separable. Use this model to analyze nonlinear correlation landslide data, taking into account the importance of the factors and the sampling rate, and to verify the results.
This study aims to compare the results (susceptibility index) according to the change of sampling data rate using Random Forest and Multi-Layer Perceptron and to verify the model performance.

Acknowledgement: This research was supported by the MSIT (Ministry of Science, ICT), Korea, under the High-Potential Individuals Global Training Program (2019-0-01561) supervised by the IITP(Institute for Information & Communications Technology Planning & Evaluation).
Study on Seismicity and Its Geodynamic Genesis in Ngari Areas
Authors: Xu Guangyin , Wu Qing , Wang Suyun
Published: March 2020

The Ngari area in Tibet is in the forefront of land-continent collisions. The area is accompanied by the polymerization of plates, forming complex structures such as the Tethys Himalayan pleat belt, the Yarlung Zangbo suture belt, and the Gangdese continental margin magma arc from the south to the north. The multi-period dive collision-inland convergence process, the geological structure is complex and the seismicity is very high. Based on the Chinese historical earthquake catalogue, the China Modern Earthquake Catalogue and the seismic data from the International Seismological Center (ISC), we analyzed the seismic activity, focal mechanism and modern tectonic stress field in the Ngari area, and then analyzed the seismicity and its source of geodynamics. The main conclusions are as follows:(1) The seismic activities in the Ngari area are mainly distributed in the Himalayan tectonic belt, the Bangong-Nujiang tectonic belt, the Alkin-East Kunlun tectonic belt, and some near north-south trending tectonic belts; (2) Earthquakes near the Himalayan tectonic belt is dominated by reverse faulting events. The seismic activity near the Bangong-Nujiang tectonic belt and the Alkin-East Kunlun tectonic belt is dominated by strike-slip earthquakes. Near the north-south extensional tectonic belt, the earthquakes show as the normal faulting events. (3) The main direction of the modern tectonic stress field in the study area is near north-south direction; (4) Seismic activity, focal mechanism and modern tectonic stress field show that the geodynamic source in the Ngari region is from Collision and squeezing the between the Eurasian plate and the Indian Ocean plate.
The Adams Event, a geomagnetic-driven environmental crisis 42,000 years ago
Authors: Cooper Alan , Turney Chris ,   Adams Event Team
Published: March 2020

Geological archives record multiple reversals of Earth’s magnetic poles, yet the potential impacts of these events remain unknown. The lack of any obvious association between the last major inversion, the Laschamps Excursion ~41 thousand years ago (ka), and polar ice paleoclimate records has underpinned the view that geomagnetic reversals do not have major environmental consequences. We find this is not the case. Importantly, the weakened geomagnetic field causes rapid production of atmospheric radiocarbon, and the lack of accurate calibration records has complicated dating of environmental and archaeological events in other parts of the world. Here we exploit the first detailed record of radiocarbon levels across the Laschamps Excursion using New Zealand swamp kauri (Agathis australis) trees to precisely align Pacific Basin environmental changes with polar paleoclimate records (via 10Be). Comprehensive radiocarbon-dated and glacial sequences are consistent with global chemistry climate modelling, and show synchronous climate changes across the mid to low latitudes that are concentrated during the geomagnetic field minima (42.2-41.5 ka) in the transitional phase that precedes the Laschamps Excursion. Critically, the revised timing reveals associations with a wide range of extinction events and major changes in the global archaeological record, which we hereby term the Adams Event. The climatic, environmental, and evolutionary impacts of past magnetic reversals now form a critical issue for future investigation.
High-resolution isotopic simulations from ECHAM6-wiso nudged with ERA5 reanalyses: new products for isotopic model-data comparisons
Authors: Cauquoin Alexandre , Werner Martin
Published: March 2020

For several decades, the comparison of climate data with results from water isotope-enabled Atmosphere General Circulation Models (AGCMs) significantly helped to a better understanding of the processes ruling the water cycle, which is one of the main drivers of the climate variability. For the modern period, the use of AGCMs nudged with weather forecasts reanalyses is a powerful way to obtain model outputs under the same weather conditions than at the sampling time of the observations.

Here we present new isotopic simulations results from ECHAM6-wiso [1] nudged with the last reanalyses dataset from the European Centre for Medium-Range Weather Forecasts (ECMWF), ERA5 [2], at different spatial resolutions over the period 1979-2018. Model results are evaluated against isotopic data compilations, including GNIP (Global Network of Isotopes in Precipitation [3]), speleothems [4], ice cores datasets and water vapor measurements. To quantify the impact of these reanalyses on our simulations, we also performed nudged simulations with the previous model version ECHAM5-wiso [5] by using ERA5 data and its predecessor ERA-Interim [6].

These new simulation products could be a useful contribution to the isotopic data community for the interpretation of their water isotope records and for the exploration of the mechanisms controlling the variability of the surrounding water isotopic composition.

 

[1] Cauquoin et al., Clim. Past, 15, 1913–1937, https://doi.org/10.5194/cp-15-1913-2019, 2019.

[2] Copernicus Climate Change Service (C3S), 2017.

[3] IAEA, the GNIP Database, available at: https://nucleus.iaea.org/wiser.

[4] Comas-Bru et al., Clim. Past, 15, 1557–1579, https://doi.org/10.5194/cp-15-1557-2019, 2019.

[5] Werner et al., Geosci. Model Dev., 9, 647–670, https://doi.org/10.5194/gmd-9-647-2016, 2016.

[6] Dee et al., Q. J. R. Meteorol. Soc., 137, 553–597, https://doi.org/10.1002/qj.828, 2011.
How changes in extreme precipitation impacts hydraulic structure design storms
Authors: Rahmani Vahid , Caporali Enrica
Published: March 2020

With a global concern about climate nonstationary and predictions of more extreme weather events, considering new rainfall distribution patterns is necessary using the most current and complete data available at any location. In this study, extreme rainfall frequency is analyzed using daily precipitation data in Kansas located in the central United States and Tuscany in the central Italy. From Kansas, 39 stations with data from 1920-2009 are selected, while for from Tuscany Region, 472 stations with daily time series of at least 15 years in the period 1916-2017 are used in the analysis. Initial analysis showed an increase in extreme precipitation events in Kansas with extreme event values tending to increase in magnitude from the northwest to southeast part of the state. Comparing results of the first period (1920-1949) to the last of three study periods (1980–2009) showed that approximately 90% of the state had an increase in short-term rainfall event magnitudes. Long-term event magnitudes were predicted to be higher in 66% of the state. Tuscany analysis is being conducted. Generally, results show a shift in rainfall distribution patterns in Kansas and Tuscany spatially and temporally. This shift changes the design criteria for hydraulic infrastructures, both in runoff control and storage structures.