bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric reconnection at the bow shock
Authors: Gunell Herbert , Hamrin Maria , Goncharov Oleksandr , De Spiegeleer Alexandre , Fuselier Stephen , Mukherjee Joey , Vaivads Andris
Published: March 2020

Can reconnection be triggered as a directional discontinuity (DD) crosses the bow shock? Here we present some unique observations of asymmetric reconnection at a quasi-perpendicular bow shock as an interplanetary DD is crossing it simultaneously with the Magnetospheric Multiscale (MMS) mission. The data show indications of ongoing reconnection at the bow shock southward of the spacecraft. The DD is also observed by several upstream spacecraft (ACE, WIND, Geotail, and THEMIS B) and one downstream in the magnetosheath (Cluster 4), but none of them resolve signatures of ongoing reconnection. We therefore suggest that reconnection was temporarily triggered as the DD was compressed by the shock. Bow shock reconnection is inevitably asymmetric with both the density and the magnetic field strength being higher on one side of the X-line (the magneosheath side) than on the other side where the plasma flow also is supersonic (the solar wind side). Asymmetric reconnection of the bow shock type has never been studied before, and the data discussed here are hence unique.
Improving PM2.5 modelling results through development of the new hourly temporal emission profile – a case study of Poland
Authors: Kryza Maciej , Werner Małgorzata , Dudek Justyna
Published: March 2020

High concentrations of atmospheric aerosols with aerodynamic diameter below 2.5 mm (PM2.5) are frequently observed in several Central European countries during the heating season (October – March). Poland belongs to a group of EU countries with the highest concentrations of PM2.5, according to the European Environmental Agency. Large exposure to atmospheric pollutants leads to significant number of premature deaths attributable to adverse air quality in Poland.

Coal combustion for residential heating is one of the main sources of PM2.5 in Poland. The quality of this fuel is often unknown, and this increases the uncertainty of national emission inventories and makes the modelling of PM2.5 concentrations challenging. Second, daily temporal emission profile (i.e. hours of the day when emission is released to the atmosphere) in residential heating sector is also rather uncertain. In this work, we developed a daily temporal emission profile using available measurements of PM2.5 and PM10 concentrations from the 2017-2018 heating season. The profile was compared with the existing profile proposed within the INERIS project. New profile has longer peak of afternoon and night time emission, if compared to INERIS, and the morning peak is significantly lower. It means that more emission is released to the atmosphere during unfavorable meteorological conditions such as calm winds and temperature inversions, which are frequently observed during the afternoon and night.

We have run two simulations using the EMEP4PL model with new and old (INERIS) emission profile. The simulations covered three heating seasons of 2015-2016, 2017-2018 and 2018-2019. Application of the new emission profile results in increased model – measurements correlation and reduced model bias.
History of Late Pleistocene Permafrost in Southern Ural revealed by studies of speleothems and cave sediments
Authors: Dublyansky Yuri , Koltai Gabriella , Scholz Denis , Meyer Michael , Gliganic Luke , Kadebskaya Olga , Cheng Hai , Spötl Christoph
Published: March 2020

In the area of the European-Asian border, in the Ural Mountains, the southern boundary of permafrost has moved in meridional direction by more than 1000 km in response to Quaternary climate variations. During cold climate states, permafrost extended as far south as the Southern Ural (53°N). We studied three independent archives in three caves in the Southern Ural (Shulgan-Tash, Victoria and Grandioznaya) in order to gain insights into the long-term dynamics of permafrost in the region.

Common speleothems (e.g., stalagmites and flowstone) require liquid water to form, and are therefore restricted to permafrost-free periods. Cryogenic cave carbonates (CCC) form when the temperature in the cave is close to or slightly below 0°C (permafrost conditions). These two types of speleothems were dated using the 230Th-U method in order to determine the timing of permafrost and permafrost-free conditions. As a novel indicator of freezing conditions in caves we identified frost wedges in silty cave sediments filled by sand. These sands were dated using OSL to constrain the timing of sub-zero rock temperatures (required to form frost wedges) in caves.

Stalagmites, abundant in in South Uralian caves, exhibit two prominent growth phases, associated with interglacials – MIS 5e and Holocene. In addition, mm-thin layers of flowstone formed in one chamber of Shulgan-Tash cave in association with smaller-scale warming episodes during MIS 3 (Greenland interstadials GI-9 and GI-8) and MIS 2 (GI-1; Bølling-Allerød). All CCC in Shulgan-Tash and Victora caves yielded MIS 3 ages, typically lagging cooling events (Greenland stadials) GS-16.1, GS-15.1, GS-13, GS-12, GS-10, and GS-7 by several hundred years up to one 1 ka. CCC from Grandioznaya cave formed during a single episode following GS-1 (Younger Dryas). Sand filling frost wedges in Victoria cave was washed into the cave during MIS 2, ca. 24-25 ka BP. Apparently, during this time the karst massif hosting the cave was engulfed by permafrost (to a depth of at least 90 m) and flow of water through the cave was severely restricted, which led to back-flooding of the cave passage and the accumulation of several m-thick silt deposits, interspersed with thin sand layers.
Performance Evaluation of PPP-AR Method for Engineering Surveys with Embedded GNSS Chipset in a Smartphone
Authors: Gul Caneren , Ocalan Taylan , Tunalioglu Nursu
Published: March 2020

Today, traditional Precise Point Positioning (PPP) method with high-cost geodetic grade Global Navigation Satellite System (GNSS) receivers has been used commonly for surveying, navigation, geodesy, geophysics and other engineering applications where dm-cm level accuracy is required. On the other hand, while smartphones have created a growing economic market in the world, they serve positioning, navigation and timing (PNT) services in varying accuracy levels to the users besides many other facilities. One of the most significant components of the smartphones involving multi-sensors for outdoor point-positioning and navigation is the embedded GNSS chipset. Especially, the world’s first dual-frequency GNSS smartphone produced by Xiaomi in May 2018, so-called Xiaomi Mi 8, brings a new aspect to PNT applications. In this study, a smartphone with dual-frequency embedded GNSS chipset was used to analyze the performance of PPP-Ambiguity Resolution (PPP-AR) method in engineering surveys. With respect to study aim, simultaneous static GNSS observations gathered with a geodetic grade GNSS receiver and a smartphone were conducted within a test setup. The static GNSS observations were repeated for 3 days and the campaign duration was 2 hours per day at the same daily time interval. All the raw GNSS observations were converted into Receiver Independent Exchange Format (RINEX) and processed by the relative point positioning method as a reference solution initially. Later, all observations were processed by the PPP-AR method. A widely used online post-processing GNSS service, namely CSRS-PPP, which was updated in August 2018 (GPSPACE to SPARK) were employed for PPP-AR solutions. As a conclusion, we analyze the performance of the embedded dual frequency GNSS chipset and assess the feasibility of them in different engineering surveys.

Keywords: Smartphone Positioning, PPP-AR, Embedded GNSS Chipset, Dual-frequency, Engineering Surveys
Simultaneous body and surface wave retrieval from the seismic ambient field and discrimination from unavoidably arising spurious artifacts
Authors: Riahi Ali , Shomali Zaher-Hossein , Obermann Anne , Kamayestani Ahmad
Published: March 2020

We simultaneously extract both, direct P-waves and Rayleigh waves, from the seismic ambient noise field recorded by a dense seismic network in Iran. With synthetics, we show that the simultaneous retrieval of body and surface waves from seismic ambient noise leads to the unavoidable appearance of spurious arrivals that could lead to misinterpretations.

We work with 2 months of seismic ambient noise records from a dense deployment of 119 sensors with interstation distances of 2 km in Iran. To retrieve body and surface waves, we calculate the cross-coherency in low-frequency ranges, i.e. frequencies up to 1.2 Hz, to provide the empirical Green’s functions between each pair of stations. To separate the P and Rayleigh waves, we use the polarization method that also enhances the small amplitude body waves.

We observe both P and Rayleigh waves with an apparent velocity of 4.9±0.3 and 1.8±0.1 km/s in the studied area, respectively, as well as S or higher mode of Rayleigh waves, with an apparent velocity of 4.1±0.1 km/s. Besides these physical arrivals, we also observe two spurious arrivals with similar amplitudes before/after the P and/or Rayleigh waves that render the discrimination challenging.

To better understanding these arrivals, we perform synthetic tests. We show that simultaneously retrieving the body and surface waves from seismic ambient noise sources will unavoidably lead to the appearance of superior arrivals in the calculation of empirical Green’s functions.
Determination of Near Fault Velocity Pulses with Multivariate Naïve Bayes Method
Authors: Ertuncay Deniz , Costa Giovanni
Published: March 2020

Near fault ground motions may contain impulse behavior on velocity records. Such signals have a particular indicator which makes it possible to distinguish them from non-impulsive signals. Impulsive signals have significant effects on structures; therefore, they have been investigated for more than 20 years. Due to its severe effect on structures, it is vital to predict its occurrence during an earthquake. To calculate the probability of occurrence, a large dataset is collected from various national data providers and NGA-West 2 database. The dataset only contains crustal earthquakes. Created dataset has a large number of parameters which carry information on the earthquake physics, ruptured faults, ground motion parameters, distance between the station and several parts of the ruptured fault. Relation between the parameters and impulsive signals are calculated. It is found that fault type, moment magnitude, distance and azimuth between a site of interest and the surface projection of the ruptured fault are correlated with the impulsiveness of the signals. These parameters are given as inputs to multivariate naïve Bayes classifier. Naïve Bayes classifier allowed us to have the probability of observing impulsive signals. Two separate models are created for strike slip and non-strike slip fault types. It is found that strike slip and non-strike slip models have an accuracy rate of 98%. These models are able to predict the probability of observing an impulsive signal for a site of interest with high accuracy rates.
Seismic hazard map of Austria
Authors: Weginger Stefan , María del Puy Papí Isaba , Jia Yan , Lenhardt Wolfgang
Published: March 2020

After 25 years, a new seismic hazard map for Austria was created. The improvements in the Probabilistic Seismic Hazard Assessment (PSHA) are based on expanded and updated catalog data with improved depth, source-mechanism and moment magnitudes. Locally adapted ground motion prediction equations (GMPE) were calculated by applying a least square adjustment to the local measurements. A neuronal networks approach was successfully tested. The final selection is carried out by using statistical parameters, like Log-Likelihood and Euclidean Distance Range. Verified calculation methods, like Bayesian Penalized Maximum Likelihood and modified Gutenberg Richter, were used. The uncertainties have been considered by using the covariance matrix according to Stromeyer (2015). The PSHA approach combines a model of seismic zones (area sources), which is composed of zones and superzones, a zone-free model (smoothed seismicity) and a model with geological fault zones. A logic tree function was used to merge the models, the maximum magnitudes (by EPRI-Approach) and the GMPE. The calculations were carried out with the Openquake software framework. The results were compared with the current norm and the results of neighboring countries. Furthermore, the uniform hazard spectra were compared with the new Eurocode draft.
Terrestrial strapdown inertial gravimetry in the Bavarian Alps
Authors: Schack Peter , Pail Roland , Gruber Thomas
Published: March 2020

Around 100km south of Munich, the Institute of Astronomical and Physical Geodesy of the Technical University of Munich established a gravimetric-astrogeodetic testing ground over the last 20 years. Precise gravity values as well as vertical deflections exist for hundreds of points. End of 2019, a car-based strapdown inertial gravimetry survey was realized in this area along a ~25km track. For this track, a few gravity values and several vertical deflections (spacing around 200m) are available (Hirt and Flury 2008). Navigation-grade IMU (inertial measurement unit), GNSS (global navigation satellite systems) and additional relative gravimeter observations were recorded during the survey. With this setup, it is possible to evaluate the capabilities of terrestrial scalar and vector strapdown inertial gravimetry.

This contribution gives an overview about the testing ground, the recently conducted survey and the data processing. The main part treats the analyses regarding the accuracy of 1D- and 3D-strapdown inertial gravimetry. Furthermore, attention is payed to the kinematic IMU performance (noise behavior), the benefit of special IMU calibrations (Becker 2016) and a comparison of the results with pure model based gravity disturbances.

Literature

Becker, D. (2016). Advanced Calibration Methods for Strapdown Airborne Gravimetry. PhD thesis, Technische Universität Darmstadt, Fachbereich Bau- und Umweltingenieurwissenschaften, Schriftenreihe der Fachrichtung Geodäsie Heft 51. ISBN 978-3-935631-40-2.

Hirt, C. and Flury J. (2008). Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data. J Geod (2008) 82:231–248, Springer-Verlag. DOI 10.1007/s00190-007-0173-x.
Introduced species in new ecosystems: concerning possible distortions of local biogeochemical cycles
Authors: Kavelenova Lyudmila , Prokhorova Nataly , Rozno Svetlana , Pomogaybin Alexander , Yankov Nikolay
Published: March 2020

The higher plants species during introduction demonstrate their properties, sometimes going beyond their traits in the natural areas. The most striking example may be given in this case is Acer nugundo L. (ash-leaved maple from the North America, a common component of forests in river valleys). In the forest-steppe –steppe landscapes of the Middle Volga region, it became a tree weed that exhibits exceptional resistance to abiotic stress conditions, including droughts.

Being introduced to alien territories, tree species generate different sorts of  “distortions” into local biogeochemical cycles in natural ecosystems and anthropogenically transformed environment. We would like to list briefly some kinds of such influence expressed in the conditions of the forest-steppe-and steppe ecosystems of our region.

The direct or indirect effects on water cycle may be connected with:

- The changes in water balance due to additional transpiration during the overgrowth of previously treeless localities with the transition from grassy to pseudo-forest communities (Ulmus foliaceae L., Acer negundo L., Elaeagnus angustifolia L.).

- The emission of additional amount of terpenes and other aeroions into the air (various types of coniferous and deciduous trees and shrubs), which can act as centers of water vapor condensation.

The direct or indirect effects on carbon cycle (as well as nitrogen and phosphorus) may be connected with:

- The formation of leaf mass not eaten by local phytophages, replenishing the fund of leaf litter (Acer negundo L., Aesculus hyppocastanum L., species of Juglans genera.).

- The influence on the soil biological activity by stimulating or inhibiting the development of soil microbiota members (different tree species including Juglans cinerea L., J. mandshurica Maxim. , J. nigra L. and others).

- The changes in the soil nitrogen balance, especially pronounced for species with "symbiotic support" (Elaeagnus angustifolia L., Hyppophae ramnoides L.).

The above effects were detected by us for the few species including named above using various field and laboratory methods. Now we can consider them at the level of their identification as such Their scale assessment at the ecosystem level may become a next stage.

An analysis of the possibilities of identifying new pseudo-forest communities developing on the grassy deposits was carried out in local conditions by integrating ground-based survey data and remote sensing. This aspect seems to be valuable for our region with highly mosaic combination of natural, cultivated, anthropogenically transformed and other territories.
Microplastic of polystyrene in soil and water: fluxes study from industrial site
Authors: Kukharchyk Tamara , Chernyuk Vladimir
Published: March 2020

In the paper the experience of investigation of polystyrene content in soil and its distribution from industrial enterprise, where expanded polystyrene foam insulation is produced more than 40 years, is presented. Polystyrene belongs to the one of the most widely produced and used polymer. Once being in the environment, this type of plastic breaks easily and crumbles, and is dispersed by wind and water. Moreover, the danger of environmental pollution by polystyrene may be very serious because of hexabromocyclododecane that can be present in polystyrene as flame retardant additive.  Unfortunately, the level of study of environmental pollution with polystyrene and his behavior in soil and water is very poor.

Methodological approaches of sampling and polystyrene identification are shown. Since the enterprise is located on the elevated area close (500-700 m) to a small river with temporary stream, the direct flow of pollutants into the floodplain is possible. Therefore, soil and technogenic deposits at industrial site as well as soil and groundwater within floodplain were collected for study.

In order to identify plastic in solid samples, multiple stages were applied including visual detection, drying, sieving (using mesh widths from 1 to 5 mm), flotation (with heating for the fractions with the size of 1-2 mm and less than 1 mm), and natural organic matter removal. Method of water filtration was used.

Polystyrene was revealed in all solid (12) and liquid (4) samples. High amounts of polystyrene particles with a size less than 5 mm were recorded in technogenic deposits (up to 16700 units/kg) and in soils (up to 1700 units/kg). Particles of microplastic (less than 1 mm) were detected not only in surface layer of soil (0-5 cm) but at the depth of 10-15 cm. Discharges of small granules (less than 1 mm) of raw materials (expanded polystyrene) into environment and its distribution with runoff away from its sources were revealed.

Necessity of further investigation of plastic and microplastic pollution in terrestrial ecosystems in impact zones, including estimates of plastic volume discharges from industrial area with waste, surface runoff and via runoff collector, in order to prevent aquatic ecosystem pollution is discussed.
Persistent earthquake-rupture segmentation due to variable interseismic slip accumulation within the southern Hellenic subduction plate-interface zone in Greece
Authors: Saltogianni Vasso , Mouslopoulou Vasiliki , Oncken Onno , Nicol Andrew , Gianniou Michael , Mertikas Stelios
Published: March 2020

Increasing evidence suggests that large thrust-faults that splay from the plate-interface to extend within the upper-plate have a significant impact on subduction seismogenesis. The manner in which these two elements, the plate-interface itself and its splay-thrust faults, interact with one another during the earthquake cycle remains, however, poorly explored. Here, we use GPS velocities, constrained by millennial fault slip-rates, to quantify the accumulation (and partitioning) of strain on individual faults of the plate-interface zone and capture their possible interactions. We zoom into the southern Hellenic Subduction System (HSS), where the greatest (M8.3) earthquake and tsunami ever recorded in the Mediterranean was produced by slip on a splay-thrust fault. Our analysis shows that the HSS is kinematically segmented and strain is accumulated at spatially variable rates along individual structures of the plate-interface zone. We find that insterseismic locking reaches up to ~85% and ~45% on the western and eastern segments, respectively, and on structures different to those that ruptured historically. Although the western HSS has been more active recently (e.g. 365 BC), the eastern HSS carries currently higher potential for large-magnitude (M>6) earthquakes andits interface-zone appears to be closer to failure. Elastic fault-interactions are responsible for both significant inter-segment variability in strain-accumulation and millennial uniformity in earthquake rupture-segmentation between eastern and western HSS.
InterFrost Project Phase 2: Updated experiment results for the validation of Cryohydrogeological codes (Frozen Inclusion)
Authors: Grenier Christophe , Costard Francois
Published: March 2020

Recent field and modelling studies indicate that a fully-coupled, multi-dimensional, thermo-hydraulic (TH) approach is required to accurately model the evolution of permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require validation. This issue was first addressed within the InterFrost IPA Action Group, by means of an intercomparison of thirteen numerical codes for two-dimensional TH test cases (TH2 & TH3). The main results (cf. Grenier et al. 2018 and wiki.lsce.ipsl.fr/interfrost) demonstrate that these codes provide robust results for the test cases considered.

The second phase of the InterFrost project is devoted to the simulation of a cold-room reference experiment based on test case TH2 (Frozen Inclusion). In a first implementation phase of the experimental setup, the initial frozen inclusion was inserted in the setup prior to the complete filling of the porous medium and the flow initiation. The thermal evolution of the system was monitored by thermistors located at the center of the initial inclusion and along the downgradient centerline. This setup provided optimal conditions to control the initial experiment geometries but resulted in slight differences in the initialization time for different experiments.

In a second implementation strategy, we now consider “in place” generation of an initial frozen inclusion through a cooling coil. The initial frozen inclusion is obtained after the initial cooling time and its initial thermal state is measured by means of an array of thermistors. In a second step, the flow is initiated, and the thermal evolution is monitored through an array of 11 thermistors (within the initial position and downgradient).

The experimental setup and an overview of all monitoring results as well as preliminary numerical simulations are presented. In an attempt to prevent formerly observed drifts in total water flowrates, the porous medium is renewed for each single experiment considering some key experimental conditions (full-flow vs. no-flow). A repetition of experiments provides an estimation of experimental uncertainty bounds. Derived results and conclusions from this experiment will form the basis for the next phase within the InterFrost validation exercise.
Deep seated density anomalies across the Iberia-Africa plate boundary and its topographic response
Authors: Jiménez-Munt Ivone , Torne Montserrat , Fernàndez Manel , Vergés Jaume , Kumar Ajay , Carballo Alberto , Garcia-Castellanos Daniel
Published: March 2020

The modes in which the lithosphere deforms during continental collision and the mechanisms involved are not well understood. While continental subduction and mantle delamination are often invoked in tectonophysical studies, these processes are difficult to be confirmed in more complex tectonic regions such as the Gibraltar Arc. We study the present-day density and compositional structure of the lithosphere along a transect running from S Iberia to N Africa crossing the western Gibraltar Arc. This region is located in the westernmost continental segment of the African-Eurasian plates, characterized by a diffuse transpressive plate boundary. An integrated and self-consistent geophysical-petrological methodology is used to model the lithosphere structure variations and the thermophysical properties of the upper mantle. The crustal structure is mainly constrained by seismic experiments and geological data, whereas the composition of the lithospheric mantle is constrained by xenolith data. The results show large lateral variations in the topography of the lithosphere-asthenosphere boundary (LAB). We distinguish different chemical lithospheric mantle domains that reproduce the main trends of the geophysical observables and the modelled P- and S-wave seismic velocities. A sublithospheric body colder than the surrounding mantle is needed beneath the Betics-Rif to adjust the measured potential fields. We link this body to the Iberian slab localized just to the east of the profile and having some effect on the geoid and Bouguer anomalies. Local isostasy allows explaining most of the topography, but an elastic thickness higher than 10 km is needed to explain local misfits between the Atlas and the Rif Mountains. This work has been supported by Spanish Ministry by the projects MITE (CGL2014-59516) and GeoCAM (PGC2018-095154-B-100).
Analysis of Fluctuation and Correlation Tendency among Precipitation, Wind, and Solar from Various Spatio-temporal Perspectives: a Case Study in China
Authors: Wang Xianxun
Published: March 2020

Analysis of correlation among precipitation, wind, and solar resources could explore their complementary features, enhance the utilization efficiency of renewable energy and further alleviate the carbon emission issues caused by fossil energy. In this study, we discuss the correlation between precipitation and wind, wind and solar, precipitation and solar from various Spatio-temporal perspectives (from east to west in China, in terms of plain, plateau, hill, and mountain, from daily to ten days and monthly) with observed data. With investigation of daily time series of precipitation, wind speed and solar radiation ranging from 1961-1-1 to 2016-12-31 of 726 meteorological stations located in various landform and distributed dispersedly in China, the results show that 1) the fluctuation value, quantified by Mei-Wang Fluctuation index, denotes the descending tendency when the time resolution increases, and this tendency is stronger in the southern and eastern China; 2) the correlation coefficient, characterized by Kendall’s rank correlation coefficient, changes from east to west in China, and the strength of this correlation displays certain connection to the local topography (e.g., in Qinghai province which is located in the plateau region the complementarity between precipitation and wind speed is stronger than that between precipitation and solar, the mid-stream basin of Yangtze River where the topography is scattered and complex has the weaker complementarity compared to other areas in China). According to the results of this research, it is helpful from the temporal perspective to understand the requirement of complementarity in the utilization of wind, and solar resources which are intermittent, and from the spatial perspective to know the solution of mitigating fluctuation via integration of multi-renewable energy situated in different locations.
What drives seasonal variations of organic aerosol over the Indo Gangetic Plain?
Authors: Mogno Caterina , Palmer Paul , Knote Christoph
Published: March 2020

The Indo Gangetic Plain (IGP), home to more than 400 million people, encompasses most of northern and eastern India, the most populated parts of Pakistan, and Bangladesh. Cities in the IGP are among the most polluted in the world, with levels of particulate matter with diametres smaller than 2.5 microns (PM2.5), often far exceeding human health recommendations. Seasonal changes in the physical and chemical environment over the IGP are dominated by the large-scale South Asian monsoon system, but also by seasonal sources such as lifting of dust from the Thar desert and agricultural stubble burning at the end of the growing seasons. Organic aerosol (OA) represents a major contribution to PM2.5. They exist in a complex mixture, comprising of thousands of individual organic compounds. OA is made up of primary OA (POA), emitted directly to the atmosphere, and by secondary OA (SOA) formed by the gas-phase oxidation of volatile organic compounds. We use the WRF-Chem regional atmospheric chemistry model to study seasonal changes in the chemical properties of fine particulate matter over the IGP. In particular, we use the Volatility Basis Set (VBS) model in WRF-Chem to study both POA and SOA seasonal variations, and to quantify the importance of seasonal sources of OA to PM2.5 over the IGP. We evaluate the model using satellite observations of aerosol optical properties.
The Potential Assessment of Environmental Disasters for Remoted Mountainous Communities nearby the Riverbank in Southern Taiwan under Climate Change
Authors: Lee Ming-Hsi , Chiang Kun-Feng , Tsai Kuang-Jung
Published: March 2020

There are almost 24% of total remoted mountainous communities located in Chiayi, Tainan, Kaohsiung and Pingtung counties/cities of southern Taiwan. During recent years, the extreme rainfall events brought huge amounts of rainfall and triggered severe environmental disasters such as landslides, debris flows, flooding and sediment disasters in southern Taiwan. The maximum rainfall of typhoon Morakot in August 2009 was approaching 3,000 mm during 4 days in mountainous area of Chiayi city. There are 359 landslides occurred nearby the remoted mountainous communities in the study area during the typhoon event. The landslide area was over 900 ha.

The potential assessments of environmental disasters for 38 remoted mountainous communities nearby the riverbank were analyzed. The landslide areas nearby the 38 communities in last 10 years (2007-2016) were identified. The numerical models (HEC-RAS, CCHE-2D and FLO-2D) were used to simulate the flooding level, scouring and deposition of river bed and the influence area of debris-flow occurrence under different return periods (25, 50 and 100 years). The results show that there are 5, 4 and 14 high potential communities of landslide, flooding and debris flow disasters, respectively. The results proposed by this study can provide the disaster risk management of administrative decisions to lessen the impacts of environmental disasters for remoted mountainous communities nearby the riverbank in southern Taiwan under climate change.
Irrigation and precipitation consistency with SMOS, SMAP, ESA-CCI, Copernicus, Neural Network SSM, AMSR-2 remotely sensed soil moisture
Authors: Corbari Chiara , paciolla nicola , Al Bitar Ahmad , Kerr Yann , Mancini Marco
Published: March 2020

Numerous surface soil moisture (SSM) products are available from remote sensing, ranging different spatial and temporal resolutions. Varying techniques are employed to retrieve SSM and different spatial scales highlight different distributions. Notwithstanding this variety between the available data, all of them should be coherent with the recorded rainfall and irrigation.

In this work we have crossed recorded precipitations with a number of SSM products deriving from remote sensing: Soil Moisture Ocean Salinity (SMOS) mission, Soil Moisture Active Passive (SMAP) mission, European Space Agency Climate Change Initiative (ESA-CCI) products, Copernicus Global Land Operations product, a Neural Network SSM retrieval algorithm and AMSR-2 data.

All the dataset products have been compared with recorded precipitation from on-ground stations over two agricultural sites in Italy: one in the north, near Lake Garda (Chiese Irrigation Consortium) and the other in the south-east in the Apulia region (Capitanata Irrigation Consortium).

In both cases, a first SSM-rain comparison through well-established indexes (Pearson and Spearman correlations) has not yielded encouraging results.

Then, a methodology has been developed to determine whether the variation of SSM is consistent with the presence/absence of precipitation. An Agreement Index (AI) has been derived as a way to measure the coherency between SSM and precipitation. Any time a measure of SSM is available, a positive or negative value for the AI is recorded, according to the rainfall registered since the previous measurement. During the irrigation season (March through September), the presence of this artificial input of water into the system is also taken into account. For every year, the proportion between “coherent” SSM-rainfall pairings (positive AIs) and “non-coherent” pairings (negative AIs) has been computed.

This method is applied to all SSM products in the dataset, and results are compared. When aggregating the results for all the pixels within the irrigation consortia, all seem to align to a similar proportion between “coherent” and “non-coherent” SSM-rainfall pairings, notwithstanding the wide variety of data types, spatial resolutions and retrieval methods. However, even if the overall performances of the products are similar, each shows different spatial distributions, as each product is influenced differently by the physical features of the different areas.
Ground scientific verification test for Moderate Resolution Imaging Camera of China’s First Mars Mission
Authors: Zhang Xiaoxia , Liu Jianjun , yan wei , Liu Dawei , Liu Donghao
Published: March 2020

China's first Mars exploration mission (HX-1) is expected to launch in 2020 with an orbiter and a rover, to conduct a global and comprehensive exploration of Mars, and to carry out regional patrolling on the Mars surface. The orbiter will be equipped with a Moderate Resolution Imaging Camera (MoRIC) to produce a global map of the Mars and study the topography of the Mars surface. The MoRIC is a color camera, works at visible spectrum, the image resolution of the camera is 100m@400km, and the FOV is 64 o.

The purpose of the Ground scientific verification test for MoRIC is to evaluate its ability to obtainhigh quality image data of the Mars surface. In the test, we made a simulation of the on-orbit detection process of MoRIC and obtained different kinds of test data, which was used to evaluate the data processing method and analyze the quality of data. The test results show that the data processing method of the MoRIC is correct; the image quality, the color correction effect and compression quality of the MoRIC data meet the requirements of the verification test.
Risks and impacts of Heat Extremes under 1.5 ℃ and 2 ℃ global warming Over Mediterranean areas
Authors: Yu Hao , Cui Xuefeng
Published: March 2020

Heat extremes have serious impact on human and agriculture over the world. As one of the prominent climate change “hot spots”, Mediterranean area, especially, its eastern area is expected to be more vulnerable to heat exposure, due to its population density and high rates of urbanization. The Paris Agreement aims to control global warming below +2℃ comparing to pre-industrial level. It is interesting to study how heat extremes would change in Mediterranean area in a +1.5 ℃ and +2 ℃ global warming world and how they impact on human and agriculture.

Based on the high resolution climate scenario data from CORDEX-MED, we calculate several heat waves indices e.g. HWN (the total number of events), HWD (the length of the longest event), HWF (the total number of heat waves days), HWA (the hottest day (amplitude) of the hottest event) and EDD (extreme degree days, 30℃ used to study impact on maize yield). We find that in most Mediterranean areas, both heat waves intensity and frequency have a robust increase in a +1.5 ℃ and +2 ℃ global warming world and cause more people exposure to heat waves in different shared socioeconomic pathways (SSPs). The most prominent areas are central Spain, Italy and Turkey. Also, more maize growing areas in Mediterranean will experience yield losses.
Submesoscale physical processes in the atmospheric boundary layer above fragmented sea ice.
Authors: Wenta Marta , Herman Agnieszka
Published: March 2020

In consequence of sea ice fragmentation in winter a range of physical processes take place between the sea/sea ice and the atmospheric boundary layer (ABL). Most of them occur on the level of individual ice floes and cracks and thus cannot be directly resolved by numerical weather prediction (NWP) models.  Parametrizations of those processes aim to describe their overall effect on grid scale values, given the grid scale variables. However, as many of the processes taking place during winter sea ice fragmentation remain largely unrecognized they cannot be incorporated into the NWP models. 

The aim of the presented study is to determine whether the floe size distribution (FSD) has an effect on the ABL. Our previous research (Wenta, Herman 2018 and 2019) indicates that FSD might determine the intensity and spatial arrangement of convection and heat fluxes. A coefficient has been proposed for the correction of moisture heat flux, which can be incorporated into the NWP models. However, this research is based entirely on idealized model simulations and requires further modelling and observations based studies.

In order to address this shortcoming, a field campaign is going to take place in the Bay of Bothnia in March 2020. Our goal is to create a 3D view of the atmosphere above fragmented sea and verify whether the processes and effects we found in the modeling results take similar form in real situations. Measurements results will be useful in the validation of our numerical modelling studies and will provide a unique dataset about the sea-ice-atmosphere interactions in the Bay of Bothnia area. Considering a significant decreasing trend in winter sea ice extent in the Baltic Sea it might contribute to our understanding of the role of ice in the local weather patterns. The field campaign is going to be complemented by numerical modelling with full version of Weather Research and Forecasting (WRF) model adjusted to the conditions over the Bay of Bothnia. 

Combined together - the results of our previous modelling studies and the results from the Bay of Bothnia field campaign, may considerably increase our knowledge about the surface-atmosphere coupling in the event of winter sea ice fragmentation.
Turbulence Observations in the Grounding Zone Region of Thwaites Glacier
Authors: Davis Peter , Nicholls Keith , Holland David
Published: March 2020

Antarctic ice shelves restrain the flow of grounded ice into the ocean, and are thus an important control on Antarctica’s contribution to global sea level rise. West Antarctica represents the largest source of uncertainty in future sea level projections, and Thwaites Glacier has the potential to influence sea level more than any other outlet glacier in this region. The future behaviour of Thwaites Glacier is particular sensitive to basal melting in the grounding zone region. Basal melting is controlled by the turbulent transfer of heat through the ice shelf-ocean boundary layer. The physics of this boundary layer is poorly understood, however, and its inadequate representation in numerical models is hampering our ability to predict the future evolution of the Antarctic ice sheet. Using a hot-water drilled access hole, a turbulence instrument cluster was deployed in the grounding zone region of Thwaites Glacier in January 2020. By observing the momentum and scalar fluxes, these observations provide a unique opportunity to explore the important turbulent processes responsible for modulating the basal melt rate in this region. Ultimately, this observational effort will allow us to better constrain our parameterisations of the grounding zone region in large-scale numerical models, facilitating more accurate simulations of the Antarctic ice sheet in the changing climate.
Energy spectra of carbon and oxygen - Predictions from HELIOS E6 for Solar Orbiter HET
Authors: Marquardt Johannes , Heber Bernd , Elftmann Robert , Wimmer-Schweingruber Robert
Published: March 2020

Anomalous cosmic rays (ACRs) are well-suited to probe the transport conditions of energetic particles in the innermost heliosphere. We revisit the HELIOS Experiment 6 (E6) data in view of the upcoming Solar Orbiter Energetic Particle Detector (EPD) suite that will perform measurements during a comparable solar minimum within the same distance.

Adapting the HELIOS energy ranges for oxygen and carbon to the ones given by the High Energy Telescope (HET) allows us to determine predictions for the upcoming measurements but also to put constraints on particle transport models that provide new insight into the boundary conditions close to the Sun.

We present here the adapted energy spectra of galactic cosmic ray (GCR) carbon and oxygen, as well as of ACR oxygen during solar quiet time periods between 1975 to 1977. Due to the higher energy threshold of HET in comparison to E6 gradients of about 20% at 15 MeV/nucleon are expected. The largest ACR gradient measured by E6 was obtained to be about 75% between 9 and 13 MeV/nucleon and 0.4 AU and 1 AU.
A multi-risk assessment of water scarcity in the south-eastern Italian Alps using a System Dynamics approach
Authors: Terzi Stefano , Sušnik Janez , Masia Sara , Torresan Silvia , Schneiderbauer Stefan , Critto Andrea
Published: March 2020

Mountain regions are facing multiple impacts due to climate change and anthropogenic activities. Shifts in precipitation and temperature are affecting the available water influencing a variety of economic activities that still rely on large quantities of water (e.g. ski tourism, energy production and agriculture). The Alps are among those areas where recent events of decreased water availability triggered emerging water disputes and spread of economic impacts across multiple sectors and from upstream high water availability areas to downstream high water demand areas. In order to make our water management systems more resilient, there is a need to unravel the interplays and dependencies that can lead to multiple impacts across multiple sectors. However, current assessments dealing with climate change usually account for a mono sectoral and single risk perspective.

This study hence shows an integrative assessment of multi-risk processes across strategic sectors of the Alpine economy. System dynamics modelling (SDM) is applied as a powerful tool to evaluate the multiple impacts stemming from interactions and feedbacks among water-food-energy economic sectors of the Noce river catchment in the Province of Trento (Italy).

The SDM developed for the Noce catchment combined outputs from physically based models to evaluate water availability and statistical assessments for water demands from three main sectors: (i) apple orchards cultivation, (ii) water releases from large dam reservoirs for hydropower production and (iii) domestic and seasonal tourism activities.

Hydrological results have been validated on historical time series (i.e. 2009-2017) and projected in the future considering RCP 4.5 and 8.5 climate change scenarios for 2021-2050 medium term and 2041-2070 long term. Results show a precipitation decrease affecting river streamflow with consequences on water stored and turbined in all dam reservoirs of the Noce catchment, especially for long-term climate change scenarios. Moreover, temperature scenarios will increase the amount of water used for agricultural irrigation from upstream to downstream. Nevertheless, decreasing population projections will have a beneficial reduction of water demand from residents, counterbalancing the increasing demand from the other sectors.

Finally, the integrated SDM fostered discussions in the Noce catchment on interplays between climate change and anthropogenic activities to tackle climate-related water scarcity.
Pore water pressure dynamics in a rock slope adjacent to a retreating valley glacier
Authors: Hugentobler Marc , Loew Simon , Roques Clément
Published: March 2020

Rock slope instabilities normally form through long-term strength degradation of initially stable slopes. The rate of progressive damage accumulation in the rock slope is expected to vary over time depending on the current environmental conditions. It is often assumed that glacial retreat, with its increased dynamics in the thermal and hydraulic boundary conditions in combination with mechanical ice unloading induce stresses that cause increased rock mass damage in adjacent slopes. However, direct field measurements to understand these dynamics and to quantify damage are rare.

In this contribution we present new data of a continuous borehole monitoring system installed in a stable rock slope beside the retreating glacier tongue of the Great Aletsch Glacier (Swiss Alps). Special focus lies on the pore water pressure evolution in order to better understand the origin of the presumably hydro-mechanically forced deformation measured in the study area. We compare data of two borehole pressure sensors installed at 50 m depth in the fractured crystalline rock, pressure fluctuations measured in a sink hole on the glacier close to our study site, and glacial melt water discharge measurements. These data show that the pore pressure variability in the slope is driven by annual snowmelt infiltration cycles, rainfall events, and the connection to the englacial water of the temperate valley glacier. We show that our in-situ measurements provide critical data to improve the understanding of the effects of a retreating valley glacier on the boundary conditions and eventually the stability of an adjacent rock slope.
Responding to Media Inquiries About Remote Triggering Interactions
Authors: Ye Lingling , Kanamori Hiroo , Lay Thorne
Published: March 2020

In the aftermath of a significant earthquake, seismologists are frequently asked questions by the media and public regarding possible interactions with recent prior events, including events at great distances away, along with prospects of larger events yet to come, both locally or remotely.  For regions with substantial earthquake catalogs that provide information on the regional Gutenberg-Richter magnitude-frequency relationship, Omori temporal aftershock statistical behavior, and aftershock productivity parameters, probabilistic responses can be provided for likelihood of nearby future events of larger magnitude (as well as expected behavior of the overall aftershock sequence). However, such procedures do not provide answers to inquiries about long-range interactions, either retrospectively for interaction with prior remote large events or prospectively for interaction with future remote large events. Dynamic triggering that may be involved in such long-range interactions occurs, often with significant temporal delay, but is not well-understood, making it difficult to respond to related inquiries. One approach to addressing such inquiries is to provide retrospective or prospective occurrence histories for large earthquakes based on global catalogs; while not providing quantitative understanding of any physical interaction, experience-based guidance on the (typically very low) chances of causal interactions can inform public understanding of likelihood of specific scenarios they are commonly very interested in.