bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling portfolio solutions for modern water systems with uncertain changes
Authors: Lund Jay R.
Published: March 2020

By historical standards, modern water systems have achieved unprecedented successes in supporting public health and economic prosperity, while diminishing threats to the environment and supporting various social objectives.  These accomplishments are imperfectly spread across the globe and face important challenges for the future.  This presentation will review how the successes of today’s portfolio approach to water management have integrated various water management technologies and institutions to provide this unprecedented performance, and the prospects and challenges to continuing and expanding these successes.  Prospects for expanding these successes to the impoverished regions and continuing these successes with changes in climate and demographics are discussed.  System analysis is seen as essential for providing guidance for continuing and managing the success and failures of integrated water management technologies and institutions.  The construction of models to improve and inform difficult societal discussions on water is essential for their success.
The relative roles of the South China Sea summer monsoon and ENSO in the Indian Ocean dipole development
Authors: Li Jianping , Zhang Yazhou , Xue Jiaqing , Zheng Fei , Wu Renguang , Ha Kyung-Ja , Feng Juang
Published: March 2020

The influence of El Niño-Southern Oscillation (ENSO) on the Indian Ocean Dipole (IOD), a coupled ocean–atmosphere mode of interannual climate variability, has been widely investigated over recent decades. However, a latest study indicates that the South China Sea summer monsoon (SCSSM) might also be responsible for IOD formation. Furthermore, an abnormal SCSSM does not always coincide with ENSO during boreal summer (June–August, JJA); consequently, the individual and combined effects of the SCSSM and ENSO on the IOD remain elusive. This study shows that the amplitude of the IOD tends to be much stronger under the coexistence of SCSSM and ENSO than that under individual SCSSM or ENSO events during JJA and autumn. The findings also indicate that the SCSSM and ENSO play the dominant role around the eastern and western poles of the IOD, respectively. An anomalous local Hadley circulation closely related to the stronger SCSSM favors anomalous southeasterly of Sumatra and Java during JJA, which enhance oceanic upwelling and subsequently result in cooling of the sea surface temperature (SST) over this area. Similarly, it can be envisaged that the contemporaneous ENSO could influence JJA SST anomalies over the western Indian Ocean via the Walker circulation coupled with oceanic variations.
Recent Changes of Riverine Sediment Fluxes from the Third Pole
Authors: Zhang Fan , Shi Xiaonan , Zeng Chen , Wang Guanxing , Chen Yao , Wang Li
Published: March 2020

 The Third Pole is the headwater of major rivers in Asia, which provide water resources for more than 2 billion people downstream. Compared with discharge, riverine sediment flux is a more sensitive variable in response to climate and land surface process changes, and also as an important index to quantify regional land degradation and soil resource changes. In this study, eight rivers originated in the Third Pole, including YerKang River, Shule River, Heihe River, Yarlung Tsangpo River, Nujiang River, Yellow River, YangTze River and Lancang River, were selected to study the variation of sediment flux in the source zone or upper reaches. Firstly, the amount and spatial variation of runoff depth and sediment yield of these rivers were explored. Secondly, the changes of riverine sediment fluxes in recent decades (1960-2017) were analyzed, with the spatial and temporal variations of sediment flux compared to climate (temperature, precipitation) and land surface process (glacier, frozen soil, vegetation cover) factors. Thirdly, the uncertainty of sediment flux variation associated with interaction of multi-factors were discussed. Finally, the significant impacts of sediment flux variation on the Third Pole environment and the safety of hydropower projects was pointed out with typical cases.
SWAT modeling for assessing future scenarios of soil erosion in West Rapti River Basin of Nepal
Authors: Talchabhadel Rocky , Nakagawa Hajime , Kawaike Kenji , Yamanoi Kazuki , Aryal Anil , Bhatta Binod , Karki Saroj
Published: March 2020

This study uses Soil Water Assessment Tool (SWAT) for watershed modeling in West Rapti River Basin (WRRB) of Nepal for assessing future scenarios of soil erosion till the end of 2100. Firstly, the river discharge was calibrated for the period (2003–2009) and validated for the period (2010-2013). We used three discharge stations (namely Mari at upstream, Bagasoti at mid-stream and Jalkundi at downstream). Secondly, sediment discharge was calibrated and validated at two sediment monitoring stations (namely Mari at upstream and Jalkundi at downstream). A Sequential Uncertainty Fitting (SUFI-2) technique was employed for the fine-tuning of sensitive hydrological parameters. The model achieved a good performance in both the calibration and validation periods. R2, NSE, PBIAS, and RSR were taken as performance indicators.  Finally, the developed model was then used to assess future scenarios of sediment yield in the WRRB. This study used five regional climate models (RCMs) for precipitation and temperature, and their ensemble under two representative concentration pathways (RCPs 4.5 and 8.5). This study analyses future scenarios for three time-frames namely, near future (NF: 2025-2049), mid future (MF: 2050-2074), and far future (FF: 2075-2099) with respect to the baseline (2003-2013). We found a significant increase in temperature in the future with annual average temperature anticipated to change from +0.76 oC to +5.8 oC and a moderate increase in precipitation with annual precipitation projected to change from -1.9% to 19.3% under different scenarios. In general, the MME shows slightly increasing precipitation (higher under RCP 4.5 than RCP 8.5), significantly increasing temperature (higher under RCP 8.5 than RCP 4.5) and moderately increasing sediment discharge. Our findings are useful for water resources and sediment management in WRRB under changing climate.
Fe isotope and Fe speciation study of water column redox dynamics during Eastern Mediterranean sapropel events S5 and S7
Authors: Matthews Alan , Benkovitz Ayelet , Teutsch Nadya , Poulton Simon , Bar-Matthews Miryam , Almogi-Labin Ahuva
Published: March 2020

Sapropels S5 and S7 formed in the semi-enclosed Eastern Mediterranean Sea  during peak interglacial periods MIS5e and MIS7a, respectively. This study investigates the dynamics of  water column redox change during their formation, through Fe isotope and Fe speciation studies of cores taken at 2550 m depth at site ODP-967 south of Cyprus. Both sapropels show an inverse correlation between δ56Fe and FeT/Al, with slopes mostly matching that found for the Black Sea, pointing to a benthic shelf to basin shuttle of Fe and subsequent precipitation of Fe sulphides in highly euxinic bottom waters. An exception to these Black Sea-type trends occurs during the later, peak stages of S7, where the negative δ56Fe - FeT/Al slope shallows. Fe speciation studies reveal that the dominant highly reactive Fe phase (FeHR) in the sapropels is pyrite, with Fe (oxyhydr)oxides forming the second major mineral component. FeHR/FeT plots show increased strengthening of anoxic water conditions during the transformation from pre-sapropel sediment into the sapropel. Nevertheless, despite the evidence for highly euxinic conditions from both Fe isotopes and high Mo concentrations in the sapropels, Fepy/FeHR ratios remain below values commonly used to identify water column euxinia. This apparent contradiction is ascribed to the sedimentary preservation of a high flux of crystalline Fe (oxyhydr)oxide minerals to the basin, which resulted in a relatively low degree of sulphidation, despite the presence of euxinic bottom waters.  Thus, the operationally defined ferruginous/euxinic boundary for Eastern Mediterranean Sea sapropels is better placed at Fepy/FeHR = 0.6, which is somewhat below the usually ascribed lower limit of 0.7. Consistent with the significant presence of crystalline Fe (oxyhydr)oxides, the change in the δ56Fe - FeT/Al slope during peak S7 is ascribed to an enhanced monsoon-driven flux of detrital Fe(III) oxides from the River Nile into the Eastern Mediterranean basin. The euxinic water column conditions that developed in sapropels S5 and S7 are interpreted to reflect the positive balance between dissolved sulphide formation and rates of reductive dissolution of Fe (oxyhydr)oxide minerals. Both of these parameters in turn depend on the extent to which water overturn times are reduced during sapropel formation. Water overturn rate is therefore considered to define the strength of euxinic water column conditions during these periods of organic carbon-rich sedimentation.
Projected climate change over Kuwait simulated using a WRF high resolution regional climate model
Authors: Alsarraf Hussain
Published: March 2020

The purpose of this study is to examine the impact of climate change on the changes on summer surface temperatures between present (2000-2010) and future (2050-2060) over the Arabian Peninsula and Kuwait. In this study, the influence of climate change in the Arabian Peninsula and especially in Kuwait was investigated by high resolution (36, 12, and 4 km grid spacing) dynamic downscaling from the Community Climate System Model CCSM4 using the WRF Weather Research and Forecasting model. The downscaling results were first validated by comparing National Centers for Environmental Prediction NCEP model outputs with the observational data. The global climate change dynamic downscaling model was run using WRF regional climate model simulations (2000-2010) and future projections (2050-2060). The influence of climate change in the Arabian Peninsula can be projected from the differences between the two period’s model simulations. The regional model simulations of the average maximum surface temperature in summertime predicted an increase from 1◦C to 3 ◦C over the summertime in Kuwait by midcentury.

 
Geoarchaeological study of big Essentuksky 1 kurgan in Ciscaucasia, Russia
Authors: Khokhlova Olga , Sverchkova Alena
Published: March 2020

The chrono-sequence of paleosols, buried under different constructions in the big kurgan Essentuksky 1 in Ciscaucasia (Stavropol region), built by people of the Maikop culture in the second quarter of the 4th millennium BC, was studied. The height of the kurgan was 5.5-6 m and diameter – more than 60 m. It had four earthen constructions and three – made of stones. We studied the composition of the material of kurgan’s constructions, paleosols buried under four earthen kurgan's constructions and the surface soil on the area adjoining to the kurgan. The macro- and micromorphological observations and set of analytical and instrumental methods were used to study the properties of soils in the chrono-sequence and composition of material from the earthen constructions. According to archaeological data, the kurgan was built for time-span from 25, but not more than 50 years. During this interval, the morphological and physicochemical properties of soils changed, namely, there was a decrease in the thickness of the humus profile and the content of organic carbon, an increase in the content of gypsum, carbon of carbonates, a shift of the area of their accumulation up the profile, and transformation of the forms of carbonate features. The percentage of the exchangeable sodium and magnesium in the composition of exchangeable bases increased and magnetic susceptibility decreased. The most “arid” properties are found in the paleosol buried last in the studied chronological sequence: the humus horizon is the lightest, the profile is most enriched in carbonates, there is the highest content of exchangeable sodium and magnesium in the composition of exchange bases, the lowest magnetic susceptibility and the maximum amount of gypsum in the second meter of the profile. During the indicated time-span of the construction of the kurgan, Haplic Chernozems Loamic changed in Calcic Chernozems Loamic. For the studied time-span, a palynological analysis revealed a decrease in forest area and an increase in the portion of grassy vegetation. In the composition of grasses, there was an increase in the proportion of steppe and xerophytic species. The climate of the studied interval (the beginning of the development of the Maikop culture in the Ciscaucasia) is characterized as drier and hotter in comparison with nowadays. The material for the earthen layers of the kurgan's constructions was taken from the gleyic horizons of the Gleysols (the lowest layer in the first and second constructions) and from the Ah and AhB horizons of the Chernozems (the overwhelming majority of the layers). This study was supported by the Russian Science Foundation, project no. 16-17-10280.
Prediction of Chlorophyll and Phosphorus in Lake Ontario by Ensemble of Neural Network Models
Authors: Sun Youyue , Li Yu , Huang Jinhui Jeanne , McBean Edward
Published: March 2020

Chlorophyll-a (CHLA) and total phosphorous (TP) are key indicators for water quality and eutrophication in lakes. It would be a great help to water management if CHLA and TP could be predicted with certain leading time to ensure water quality control measures could be implemented. Since eutrophication is the results of a complex bio-chemical-physical processes involving in pH, temperature, dissolved oxygen (DO) and many other water quality parameters, the discover of their internal correlations and relationships may help in the predication of CHLA and TP. In this study, a long term (20 years) water quality data including CHLA, TP, total nitrogen (TN), turbidity (TB), sulphate, pH, and DO collected in Lake Ontario by the Environment and Climate Change Canada agency were obtained. These data were analyzed by using a group of Neural Network (NN) models and ensemble strategies were evaluated in this study. One particular ensemble of the following NN models, namely, back propagation, Kohonen, probabilistic neural network (PNN), generalized regression neural network (GRNN), or group method of data handling (GMDH) were selected which has higher goodness of fit and shows robustness in model validation. Comparing with one single NN model, the ensemble model could provide more accurate predictions of CHLA and TP concentration in Lake Ontario and the predication of CHLA and TP would be helpful in lake management, eco-restoration and public health risk assessment.
Spatiotemporal evolution of drought events and its contribution on vegetation growth in the river source region
Authors: Zhu Shuang
Published: March 2020

Climate change has been proved to exacerbate drought events and further cause huge economic and ecological losses worldwide. Therefore, it is of great significance to study the long-term evolution characteristics of drought events and quantify the impact of drought events on typical ecological indexes. Based on the measured historical precipitation data, the standardized precipitation index of different time scales was extracted to measure water deficit. The leaf area index with wide range and high precision was generated based on the Modis remote sensing image and denoising processing to represent vegetation growth. Trend analysis and change point analysis were carried out to study the spatiotemporal evolution characteristics of the concerned drought indexes. Then, with hypothesis test, appropriate copula multivariate analysis method was innovatively introduced to construct joint distribution of the standardized precipitation index and leaf area index. The contribution of drought on vegetation growth was expected to be quantified by deriving the conditional copula and preset marginal distributions. The upper Yangtze River where biomass is extremely sensitive to climate change was taken as a study area. The results show that drought events in this region have significant spatial heterogeneity. The leaf area index is highly influenced by the meteorological drought index. From no drought to severe drought, the vegetation index is distributed more and more toward the low value. Copula is very potential to find the inner relationship of the standardized precipitation index and leaf area index. The study is useful to deepen the understanding of the internal mechanism of drought events and discuss reasonable disaster prevention and mitigation countermeasures.

 
Eddies and their energetics in the Bay of Bengal
Authors: Chandra Navin , Pant Vimlesh
Published: March 2020

Eddies are integral part of ocean circulation. They play an important role in energy transfer. The surface kinetic energy in eddies can be ten times higher than the energy of the current through which these are generated. Eddies influence the thermodynamic characteristics of the upper-ocean. Oceanic eddies trap and transport hot (cold) water in the core of an anticyclonic (cyclonic) eddy. Therefore, these eddies can modify the thermal structure by the advection of temperature anomalies and its subsequent mixing. Generation of eddies takes place mainly due to the baroclinic instability of the ocean. However, some of the eddies may form due to coastal and bathymetrical geometry. The Bay of Bengal (BoB) is an enclosed basin in the northern Indian Ocean (IO). The BoB exhibits unique physical and dynamical properties due to surplus low-saline waters and shallow mixed layer. It observes seasonal variation of wind and changes in the surface current pattern. Major rivers originating from the Himalayan glaciers drain into the BoB throughout the year with a peak in July-October. The riverine freshwater together with strong post-monsoon (October-November) coastal current generate complex and turbulent surface current pattern with a large number of eddies in the BoB. The wind forcing, coastal currents, and bathymetry make favorable conditions for the generation of eddies in the BoB. In the present study, a numerical ocean model Regional Ocean Modelling System (ROMS) used to simulate the mesoscale eddies in the BoB. The ROMS model uses sigma vertical coordinates which helps in taking account of the effects of coastal and bathymetrical structures on surface circulation and eddy generation. The model results are verified with the available observations. For the detection and tracking of eddies at the surface, both the geometrical and dynamical methods are used. The geometrical method is based on the identification of local minima and maxima of dynamic sea surface height. Whereas, the dynamical method utilizes current turbulences arising from strain or vorticity to identify eddies. Using model simulations, the cyclonic and anticyclonic eddies are identified in the BoB. The life span (time period) and the kinetic energy of individual eddies are calculated. The spatial and temporal distribution of eddies and their energetics in the BoB are discussed. Further, the propagation tracks of individual eddies are estimated.
Mapping Subsurface Drainage in Agricultural Areas Using a Frequency-Domain Ground Penetrating Radar
Authors: Koganti Triven , Van De Vijver Ellen , J. Allred Barry , H. Greve Mogens , Ringgaard Jørgen , V. Iversen Bo
Published: March 2020

Artificial subsurface drainage systems are installed in agricultural areas to remove excess water and convert poorly naturally drained soils into productive cropland. Some of the most productive agricultural regions in the world are a result of subsurface drainage practices. Drain lines provide a shortened pathway for the release of nutrients and pesticides into the environment, which presents a potentially increased risk for eutrophication and contamination of surface water bodies. Knowledge of drain line locations is often lacking. This complicates the understanding of the local hydrology and solute dynamics and the consequent planning of mitigation strategies such as constructed wetlands, saturated buffers, bioreactors, and nitrate and phosphate filters. In addition, accurate knowledge of the existing subsurface drainage system is required in designing the installation of a new set of drain lines to enhance soil water removal efficiency. The traditional methods of drainage mapping involve the use of tile probes and trenching equipment which are time-consuming, tiresome, and invasive, thereby carrying an inherent risk of damaging the drain pipes. Non-invasive geophysical sensors provide a potential alternative solution to the problem. Previous research has focused on the use of time-domain ground penetrating radar (GPR) with variable success depending on local soil and hydrological conditions and the center frequency of the specific equipment used. For example, 250 MHz antennas proved to be more suitable for drain line mapping. Recent technological advancements enabled the collection of high-resolution spatially exhaustive data. In this study, we present the use of a stepped-frequency continuous wave (SFCW) 3D-GPR (GeoScope Mk IV 3D-Radar with DXG1820 antenna array) mounted in a motorized survey configuration with real-time georeferencing for subsurface drainage mapping. The 3D-GPR system offers more flexibility for application to different (sub)surface conditions due to the coverage of wide frequency bandwidth (60-3000 MHz). In addition, the wide array swathe of the antenna array (1.5 m covered by 20 measurement channels) enables effective coverage of three-dimensional (3D) space. The surveys were performed on twelve different study sites with various soil types with textures ranging from sand to clay till. While we achieved good success in finding the drainage pipes at five sites with sandy, sandy loam, loamy sand and organic topsoils, the results at the other seven sites with more clay-rich soils were less successful. The high attenuation of electromagnetic waves in highly conductive clay-rich soils, which limits the penetration depth of the 3D-GPR system, can explain our findings obtained in this research.
Test of Dust Emission Over the Middle East
Authors: Mostamandi Mokhammad Suleiman , Stenchikov Georgiy , Ukhov Alexander , Shevchenko Illia , Engelbrecht Johann , Alshehri Yasser , Anisimov Anatolii
Published: March 2020

Abstract

The dust emission simulated within the up-to-date global and regional models differs by almost an order of magnitude. The models are tuned to reproduce the observed aerosol optical depth (AOD) that, with some caveats, reflects the dust mass retained in the atmosphere. However, the amount of dust suspended in the atmosphere is controlled independently by the dust emission and deposition; therefore, only AOD observations are insufficient to constrain both these processes. To calculate the dust emission over the Middle East (ME), in this study, we employ dust deposition observations, AERONET AOD, micro-pulse lidar, and satellite observations to constrain the WRF-Chem simulations. The dust deposition is measured on a monthly bases for 2015-2019 using passive samplers over six sites over land and the sea. We compare the WRF-Chem simulations, conducted with 10-km grid spacing, with the recent MERRA-2 and CAMS reanalysis. WRF-Chem is configured with the GOCART dust scheme. We calculate the meteorological and aerosol initial and boundary conditions using the MERRA-2 reanalysis. 

We evaluated the dust regional mass balance controlled by emission, deposition, and cross-boundary transport. The smallest dust particles are transported at vast distances while the heaviest ones deposit inside of the domain. Since the model accounts for dust particles with radii<10 um, we process the deposition samples to extract the weight of particles smaller than 10 um. WRF-Chem was tuned to reproduce the observed AOD and monthly deposition of dust particles with radii < 10 um. We found that the ME dust emission comprises about 30% of the global annual dust emission. MERRA-2 underestimates the ME dust emission by about 15%.
Static-dynamic strain response to the 2016 M6.2 Hutubi earthquake (eastern Tien Shan, NW China) recorded in a borehole strainmeter network
Authors: Gong Zheng , Jing Yan , Li Haibing
Published: March 2020

Strain caused by earthquakes give rise to many earthquake-related hydrological changes. Mechanisms responsible for them are different from place to place, depending on whether the trigger is the static strain or dynamic strain. Theoretic calculation indicates that the great difference in dependence on epicentral distance is robust enough to discriminate them, however, few studies based on direct strain measurements have tested this hypothesis. The 2016 M6.2 Hutubi Earthquake is a reverse event occurred in the northern Chinese Tien Shan, and the coseismic strain responses have been recorded by nine 4-component RZB borehole strainmeters at the distance from near field to far field. The nearest four stations have recorded resolvable static strain responses, and all stations have perfectly recorded the dynamic strain waves. Our result shows that the difference in the dependence on distance is truly reliable to differentiate static strains from dynamic strains, the static strain is of the same magnitude with the dynamic strain in the near field, and as the distance increase to intermediate and far field, the static strain are a few magnitude smaller. Yet the ratio between them is a complex index relating to the rupturing process itself, the tectonic background, and the seismic wave radiation pattern. Furthermore, the calibrated static strain were also used to relocate the fault plane through a grid-search method, and the result shows that the seismogenic fault is surprisingly a high-angle backthrust fault. The determined fault parameters are 279°/70°/87°, which are also consistent with the aftershock distribution. It indicates that the high-angle backthrust in the Chinese Tien Shan are capable of breaking individually. Considering the high vertical displacement, and their abundance inside the Tien Shan orogenic belt, the high-angle backthrust faults may had also played a significant role in building the modern ultra-high relief in Tien Shan.
Remote Real-time Riprap Protection Erosion AssessmenT on large rivers
Authors: Gilja Gordon , Cikojević Antonija , Potočki Kristina , Varga Matej , Adžaga Nikola
Published: March 2020

Large number of bridges in Europe is at the end of their life span, while the frequency of occurrence for extreme climatic events, driven by climate change, is increasing. Floods influence morphodynamic changes in the riverbed, such as scouring of the riverbed next to the bridge substructure, that can undermine the overall stability of the bridge. Placement of riprap protection around bridge piers is an approach that doesn’t solve scouring problem, it rather displaces the scour hole elsewhere in the river channel, where its location is unknown because it is formed in the interaction between the flow and the structure, in site-specific conditions. Traditional approach to scour monitoring is effective only if surveys are conducted during the flood conditions, while the data acquired post-flood can underestimate the full potential of flood hazard. Detailed field surveys of hydraulic parameters during floods are essential in the understanding of morphodynamic evolution of the river channel, but are often scarce because they are time-consuming and require extensive resources (e.g. the survey equipment). Therefore, the majority of research was conducted using hydraulic flumes where both flow and the riverbed conditions are idealized 

The goal of the R3PEAT project (Remote Real-time Riprap Protection Erosion AssessmenT on large rivers) is to bridge the gap between the real-time scour hole development and flow environment through development of real-time scour monitoring system. The research focus of the project is investigation of scouring processes next to the riprap protection around bridge piers - existing structures whose stability and safety are unknown in the hydraulic environment under the influence of climate change. Research methodology combines experimental investigations on scaled physical model (Phase I) with 3D numerical model (Phase II) into hybrid modelling approach, calibrated and validated with field surveys. The research objectives of the project are: (1) develop ScourBuoy prototype (2); calibrate the physical model with field surveys; (3) improve existing empirical equations for equilibrium scour hole development using hybrid modelling approach; (4) investigate the dependence between turbulent flow characteristics and temporal scour hole development and (5) investigate dependence between turbulent conditions and incipient motion of sediment particles. The impact of the proposed project on the bridge management systems is expected through the development of a practical remote real-time system for erosion estimation around the riprap protection on large rivers that can be basis for the real-time decision support system.

Acknowledgment:
This work has been supported in part by Croatian Science Foundation under the project R3PEAT (UIP-2019-04-4046)
Modeling the impact of 1.5 and 2.0◦C global warming on the hydrology of the Faleme river basin (West Africa)
Authors: Mbaye Mamadou Lamine , Sy Khadidiatou , Faty Bakary , Sall Saidou Moustapha
Published: March 2020

Climate change raises many questions about the future availability of water resources in West Africa. Indeed, water in this region is a fundamental element for many socio-economic activities. This study proposes an assessment of the impact of climate change on the hydrology of the Faleme basin, located in the Sahel (West Africa). The applied methodology consists in calibrating and validating the hydrological model GR4J before simulating the future evolution of flows in this catchment under of 1.5 and 2°C global warming.  Observed rainfall, potential evapotranspiration (PET), and river flows were used for calibration and validation of the GR4J model. Furthermore, output of three regional climate models (DMI-HIRHAM, SHIM-RCA, and BCCR-WRF) were bias corrected with the cumulative distribution function-transform (CDF-t) before used as input to the GR4J hydrological model to simulate future flows at the watershed scale. During the historical period the results shows a good correspondence between the simulated flows and those observed during calibration and validation, with Nash–Sutcliffe efficiencies (NSE) greater than 70%. Projections show a general increase in mean annual temperature and PET; a decrease in mean annual rainfall is projected by the DMI-HIRHAM, BCCR-WRF models and the overall mean; while a slight increase is noted with the SMHI-RCA model. As for future flows, a downward trend in annual and monthly average flows is expected in the two sub-basins of the Faleme (Kidira and Gourbassi) with input from the DMI-HIRHAM, BCCR-WRF models and the overall mean; however,  the GR4J forced by the SMHI-RCA model output, project increased flows. Furthermore, the decrease is more pronounced at Gourbassi sub-basin than at Kidira sub-basin. Thus, recommendations were made to mitigate the likely impacts of climate change on socio-economic activities that use water resources.
Assessments of Assimilation of TEMPEST-D into the NCEP Global Forecast System
Authors: Wu Ting-Chi , Zupanski Milija , Grasso Lewis , Fluke James , Cronk Heather , Kliewer Anton , Schulte Richard , Berg Wesley , Kummerow Christian , Partain Philip , Miller Steven
Published: March 2020

Unlike large, expensive, and high-risk operational satellites, small/cube satellites (SmallSats) are a small, inexpensive, and a low-risk type of satellite. As a NOAA Cooperative Institute with specialties in satellite data processing and data assimilation, CIRA is funded by a Technology Maturation Program (TMP) research project to help NOAA exploit upcoming constellation of SmallSats to be considered for use in operations. In this research, a CSU-led technology demonstration mission entitled “the Temporal Experiment for Storms and Tropical System - Demonstration (TEMPTEST-D)” is used as an example to explore quick and agile methodologies to entrain SmallSats into the NOAA processing stream. Specifically, a workflow that enables TEMPEST-D data for assimilation into the NCEP Global Forecast System (GFS) with Finite-Volume Cube-Sphered (FV3) dycore (FV3GFS) under the Gridpoint Statistical Interpolation (GSI) based hybrid 4DEnVar system is established.

One objective of this TMP research project is to assess the impact of SmallSat data on NOAA modeling and assimilation systems used in operations. We begin by asking whether the use of TEMPEST-D data is as good as the use of those obtained from well-established operational satellite sensors. Since the radiometric specification of TEMPEST-D is similar to the Microwave Humidity Sounder (MHS), we address the above question by directly comparing the following three cycled FV3GFS data assimilation and forecasting experiments: 1) the control experiment, which includes all routinely assimilated observations, but only assimilates MHS from the NOAA-19 and MetOp-B platforms, 2) the AddMHS experiment, which is the control plus MHS from the MetOp-A platform, and 3) the AddTEMPEST experiment, which is the control plus TEMPEST-D.

By differentiating the AddMHS and AddTEMPEST experiments against the control experiment, we will be able to demonstrate that a cost-effective TEMPEST-D is as beneficial as a well-established operational satellite like MHS, in terms of aiding operational global weather forecasting. In addition, results from this research offers implications of the utility of a constellation of SmallSats microwave radiometers for global weather forecasting.  
How to manage a monitoring service based on satellite interferometry: a practical approach from the Tuscany region (central Italy)
Authors: Del Soldato Matteo , Solari Lorenzo , Raspini Federico , Bianchini Silvia , Ciampalini Andrea , Montalti Roberto , Casagli Nicola
Published: March 2020

Thanks to the launch of the ESA’s Sentinel-1 constellation the scientific community re-evaluated the way to use these data, shifting from a static view of the territory to a continuous streaming of ground motion measurements from space. The Tuscany region (central Italy) has been the first worldwide region to adopt a satellite continuous monitoring service for ground deformation. Taking advantage from the wide area coverage, short revisiting time, cost efficiency and non-invasiveness of the satellite interferometric techniques, in addition to the increased processing capabilities, it was possible to set up a 12 days updated system. The processing chain combines the SqueeSAR algorithm and a time-series data mining algorithm aimed to highlight benchmarks, named “anomalous points”, with significant trend variations. The anomalous points are radar-interpreted in order to classify all of them according to possible causes (e.g. landslide, subsidence, uplift, mining activity). The results of each update of the service are delivered to the regional authorities in the form of a bulletin. It contains a map of the tuscan municipalities differently coloured according to the number of anomalous points, their persistence and relevance. In case of anomalous points representing a potential threat, a field campaign for field-verifying the situation and the potential active phenomena is conducted.

A sheet survey has been realized for the field campaign in order to collect several useful information with the final aim of qualitatively estimating the risk and suggesting short-term actions to be taken by local entities. It is useful to have a complete vision on several elements following a sort of checklist (i.e. general information for describing the phenomena, intensity of the event noting down the damage, exposure of elements) drastically reducing the subjectivity of the surveyors. The whole procedure, from the download and processing of the satellite raw images to the field surveys, requires less than 10 days. The monitoring service provides extremely useful information for prevention, monitoring and risk management activities related to hydrogeological phenomena. Another important consequence is the raised awareness of local and regional authorities in terms of geohazards affecting their territories.
Uncertainty Quantification of Borehole Thermal Energy Storage Facilities
Authors: Steinbach Philipp , Lang Jens , Schulte Daniel Otto , Sass Ingo
Published: March 2020

Borehole thermal energy storages (BTES) have become a common implement for extracting and/or storing heat energy from and into the soil. Building these facilities is expensive, especially the drilling of boreholes, into which borehole heat exchangers are inserted. To cut costs, drilling methods, which can produce inaccuracies of varying degree, are utilized. This brings into question how much these inaccuracies could potentially affect the energy storage/extraction performance of a planned facility. To this end, we performed an uncertainty quantification for seasonally operated BTES facilities, where we studied the influence of geometries deviating from the planned layout and other sources of uncertainty, such as varying soil and material parameters.
In our research, we make use of a 3D simulation model for BTES facilities in a patch of soil with optional groundwater flow, designed as a system of partial differential equations (PDEs). The system is solved with a simulation toolkit, which was programmed as an extension for the finite element method solver KARDOS. The toolkit builds on previous work for the simulation tool BASIMO and was validated with benchmarks calculated with the commercial software FEFLOW, which specializes in heat transfer in porous media among other things. For the uncertainty quantification, we utilize an adaptive, anisotropic stochastic collocation method, which uses solutions of the PDE system as samples. We present the method and apply it to an illustrative as well as a practical example. Lastly, we discuss the results and assess the impact of deviating borehole paths on the performance of BTES facilities.
Analytical Model for Tsunami Propagation including Source Kinematics
Authors: Fuentes Mauricio , Uribe Francisco , Riquelme Sebastian , Campos Jaime
Published: March 2020

There are only a few analytical 2+1 D models for tsunami propagation, in which most of them treat the tsunami generation as an isolated part from a static deformation field, usually obtained from seismic models. This work examines the behavior of the tsunami propagation in a simple set-up including a time source function which accounts for a time description of the rupture process on the seismic source. An analytical solution is derived in the wavenumber domain, which is quickly inverted to space with the Fast Fourier Transform. The solution is obtained in closed form in the 1+1D case. The inclusion of temporal parameters of the source such as rise time and rupture velocity reveals a specific domain of slow earthquakes that enhance the tsunami amplitudes and produce non-negligible shifts on the arrival times. The obtained results confirm that amplification occurs when the rupture velocity matches the long-wave tsunami speed and the static approximation corresponds to a limit case for (relatively) fast ruptures. 
“Endurance”, a new NASA mission to gauge Earth’s polar wind ambipolar electric field
Authors: Collinson Glyn , Glocer Alex , Pfaff Robert , Michell Robert , Barjatya Aroh , Clemmons James , Eparvier Frank , Imber Suzanne , Lester Mark , Mitchell David , King Max , Bissett Scott
Published: March 2020

Earth’s primary ionospheric loss process is the polar wind, which flows outwards along open magnetic field lines above our polar caps. One key component critical to the formation of this outflow is thought to be a weak ambipolar electric field. The potential drop resulting from this electric field is thought to assist terrestrial atmospheric escape since it reduces the potential barrier required for heavier ions (such as O+) to escape and accelerates light ions (such as H+) to escape velocity. Although a key component to atmospheric loss, Earth’s ambipolar electric field has never been measured due to its weak strength.

 

We announce the NASA Endurance mission, launching in 2022, which will attempt to make the first direct in-situ observations of Earth’s ambipolar electric field. Endurance launch from Ny-Ålesund, Svalbard, and soar across the exobase to altitudes greater than 800km. The spacecraft will be equipped with a new type of scientific instrument which will enable the Endurance to measure the total electric potential drop below her. She will also be equipped with a full array of sensors that will enable the science team to self-consistently model the polar wind during the flight to test our current theoretical understanding of the physical processes which generate Earth’s ambipolar electric field.

Endurance will perform groundbreaking discovery science, measuring a fundamental property of Earth for the first time: the strength of the ambipolar electric field generated by its ionosphere. The results will provide us with a better understanding of atmospheric escape at Earth, and why our planet is habitable.
Mean areal rainfall improvement using radar rainfall estimation technique by considering geographic character for dam operation
Authors: Yoon Seongsim , Shin Hongjoon , Choi Gian
Published: March 2020

Efficiently dam operation is necessary to secure water resources and to respond to floods. For the dam operation, the amount of dam inflow should be accurately calculate. Rainfall information is important for the amount of dam inflow estimation and prediction therefore rainfall should be observed accurately. However, it is difficult to observe the rainfall due to poor density of rain gauges because of the dam is located in the mountainous region. Moreover, ground raingauges are limitted to localized heavy rainfall, which is increasing in frequency due to climate changes. The advantage of radar is that it can obtain high-resolution grid rainfall data because radar can observe the spatial distribution of rainfall. The radar rainfall are less accurate than ground gauge data. For the accuracy improvement of radar rainfall, many adjustment methods using ground gauges, have been suggested. For dam basin, because the density of ground gauge is low, there are limitations when apply the bias adjustment methods. Especially, the localized heavy rainfall occurred in the mountainous area depending on the topography. In this study, we will develop a radar rainfall adjustment method considering the orographic effect. The method considers the elevation to obtain kriged rainfall and apply conditional merging skill for the accuracy improvement of the radar rainfall. Based on this method, we are going to estimate the mean areal precipitation for hydropower dam basin. And, we will compare and evaluate the results of various adjustment methods in term of mean areal precipitation and dam inflow.

This work was supported by KOREA HYDRO & NUCLEAR POWER CO., LTD (No. 2018-Tech-20)

 

 
Provenance and Transport Process of Fine Sediments in Central South Sea Mud
Authors: cho hyen goo
Published: March 2020

The Central South Sea Mud (CSSM), developed in the Seomjin River estuary, is known to be supplied with sediments from Heuksan Mud Belt (HMB) and Seomjin River. However, in order to form a mud belt, more sediments must be supplied than supplied in the above areas. In this study, clay minerals, major elements analyzes were performed on cores 16PCT-GC01 and 16PCT-GC03 in order to investigate the transition in the provenance and transport pathway of sediments in CSSM. The Huanghe sediments are characterized by higher smectite and the Changjiang sediments are characterized by higher illite. Korean river sediments contain more kaolinite and chlorite than those of chinese rivers. Korean river sediments have higher Al, Fe, K concentraion than Chinese river sediments and Chinese rivers have higher Ca, Mg, Na than those of Korean rivers. Therefore, clay minerals and major elements can be a useful indicator for provenance. Based on our results, CSSM can be divided into three sediment units. Unit 3, which corresponds to the lowstand stage, is interpreted that sediments from Huanghe were supplied to the study area by coastal or tidal currents. Unit 2, which corresponds to the transgressive stage, is interpreted to have a weaker Huanghe effect and a stronger Changjiang and Korean rivers effect. Unit 1, which corresponds to the highstand stage when the sea level is the same as present and current circulation system is formed, is interpreted that sediments from Changjiang and Korean rivers are supplied to the research area through the current.
Combination of basin modeling and pyrrolic nitrogen compounds to investigate the secondary oil migration pathway in the Dongying Depression of Bohai Bay Basin, China
Authors: Chen Jiaxu , Guo Xiaowen
Published: March 2020

This study investigates the pathway of secondary oil migration which leads to the oil accumulation in Dongying Depression using basin modeling and pyrrolic nitrogen compounds. Modeling of oil migration pathways have been conducted for the third and fourth member (Es3&Es4) of Shahejie Formation including the reconstruction of burial history, thermal maturation and hydrocarbon generation processes, which are calibrated by parameters of pyrrolic nitrogen compounds and further reinforced by distributions of oil wells and fields. Carbazole parameters, such as 1-/4-methylcarbazole (1-/4-MC), 1,8-/2,7-dimethylcarbazole (1,8-/2,7-DMC) and benzo[a]carbazole/(benzo[a]carbazole + benzo[c]carbazole) ([a]/[a] + [c]) are presented to trace the oil migration pathways. The investigated 38 oil samples can be classified into three groups considering the effects of biodegradation, thermal maturation and the variation in source facies. The group I oils are derived from the lower interval of Es3, the group III oils are originated from the upper interval of Es4, and the group II oils are admixing of the source-rock intervals of Es3 and of Es4. Nine migration pathways can be determined using the abovementioned carbazole parameters. In specific, ratios of 1-/4-MC and 1,8-/2,7-DMC increase and [a]/[a] + [c] decreases as the increasing of oil migration distance. Meanwhile, the oil migration pathways resulted from basin modeling are in good agreement with those determined by pyrrolic nitrogen compounds. Most of the investigated oil wells and fields are located on the predicted migration pathways. In a nutshell, two favorable oil accumulation areas have been predicted along the migration pathways of oil in the Es4 member of Dongying Depression.