bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Digital and 3D Visualisation Technology in Planning for Woodland Expansion
Authors: Wang Chen , Gimona Alessandro , Compagnucci Andrea Baggio , Jiang Yang
Published: March 2020

Forests and woodlands offer many benefits to people. They can provide timber and food, store carbon to help deal with the effects of climate change, decrease flooding and soil erosion, and provide recreation for people and habitat for a multitude of species we care to conserve. Scottish forests cover roughly 19% of the country. The Scottish government has the ambition to add several thousand hectares a year over the next decades, to support the rural economy, the environment, and communities. It is important that a substantial proportion of the expansion is made up by native trees and shrub species due to better habitat for wildlife.

These challenges were explored with a case study of virtual forest landscape from Cairngorms National Park (CNP) which was used to test preferences for scenarios of future woodland expansion. Spatial Multi-criteria Analysis (sMCA) has been applied to decide where to plant new forests and woodlands, recognizing a range of land-use objectives while acknowledging concerns about possible conflicts with other uses of the land. The tools used in the development and implementation of the 3D model were PC and Mobile based, and enable the incorporation of interactive functionality for manipulating features. Model inputs comprise 5m DTM, 25cm Aerial Imagery, 3D Tree Species, GIS layers of Current Forest and Woodland Expansion inside CNP. Afforestation animation has been attached in Google My Maps. This is through setting different keyframes by storyboard camera path animation around the area of CNP. Stereo panorama has been applied to selection of woodland expansion scenarios (e.g. Broadleaved potential corridors, Conifer potential corridors), which is viewed with mobile technology and Virtual Reality (VR) equipment.

The 3D model with simulation of woodland expansion was used at the event of 2019 Royal Highland Show and European Forest Institute Annual Conference 2019. Audience feedback suggested the enhancement of user interaction through VR has potential implications for the planning of future woodland to increase the effectiveness of their use and contribution to wider sustainable ecosystems.
Bay of Bengal‐East Asia‐Pacific Teleconnection in Boreal Summer
Authors: Cao Jie
Published: March 2020

A new teleconnection pattern (the BEAP) across the Bay of Bengal‐East Asia‐Pacific region in boreal summer is revealed in this study using mainly ERA‐Interim reanalysis data from the European Centre for Medium‐Range Weather Forecasts. The BEAP index (BEAPI) is defined as the signed sum of standardized apparent moisture sinks at five centers along the pathway. Correlation analysis of the apparent heat sources and apparent moisture sinks has verified the existence of the BEAP teleconnection. Variations in BEAP can affect precipitation anomalies resulting from the anomalous moisture transport and the antiphase surface temperature variation. Wave flux analysis has verified the Rossby wave propagation route that originates around the central Bay of Bengal and extends across North China to the West Pacific. La Niña‐type sea surface temperature anomalies (SSTAs) appearing simultaneously in the same season can excite a positive BEAP pattern by enhancing convection over the Bay of Bengal, while El Niño‐type SSTAs have the opposite effect. Significant correlation between the BEAPI and the SSTAs can last from early summer to early winter. Numerical experiments confirm the BEAP teleconnection pattern and the associated physical processes.
Study on air-sea CO2 exchange with wave breaking
Authors: Li Shuo , Babanin Alexander , Qiao Fangli , Dai Dejun , Jiang Shumin , Guan Changlong
Published: March 2020

Hydrodynamic processes at air-sea interface play a significant role on air-sea CO2 gas exchange, which further affects global carbon cycle and climate change. CO2 gas transfer velocity (KCO2) is generally parameterized with wind speed but ocean surface waves have direct impact on the gas exchange. Thus, the relationship between wave breaking and CO2 gas exchange was studied through laboratory experiments and by utilizing field campaign data. The results from laboratory show that wave breaking plays a significant role in CO2 gas exchange in all experiments while wind forcing can also influence KCO2. A non-dimensional empirical formula is established in which KCO2 is expressed as the product of wave breaking probability, transformed Reynolds number and an enhancement factor of wind speed. The parameterization is then improved by considering the bubble-mediated gas transfer based on both laboratory and ship campaign data sets. In the end, the formula is employed in the estimation of global CO2 uptake by ocean and the result is found consistent with reported values.
Benefits and limits of season-ahead forecasts for hydropower production: a global analysis
Authors: Ng Jia Yi , Lee Donghoon , Galelli Stefano , Block Paul
Published: March 2020

Season-ahead hydro-climatological forecasts are a useful source of information for hydropower operators: at the onset of a flooding season, for example, predictive information on the timing and magnitude of the inflow volume can help operators schedule the release trajectory, decide on the amount of volume to store, and therefore maximize hydropower production. Intuitively, the forecast value varies not only with predictive accuracy, or skill, but also with the reservoir design specifications. Characterizing and explaining the relationship between skill, design specifications, and value is thus a necessary step towards a more informed and effective use of seasonal forecasts. To investigate the nature of this relationship, we modeled 1,593 hydropower reservoirs, for which we developed 3-month ahead monthly inflow forecasts—based on a principal component linear regression model. Our results show that more than half of the dams could benefit from forecasts, averaging a 6.56% annual increase in hydropower production. We also found that forecast value is largely controlled by reservoir design specifications; specifically, we found that reservoirs with small storage capacity (relative to inflow) and large inflow volumes (relative to turbine capacity) have better chances of benefitting from accurate forecasts. With this information, we classify and map each dam on the basis of its potential to increase hydropower production.
A mobile sensor-based Approach for Analyzing and Mitigating Urban Heat Hazards
Authors: Yin Yanzhe , Grundstein Andrew , Mishra Deepak , Hashemi Navid , Lakshmish Lakshmish
Published: March 2020

High-quality temperature data at a finer spatial-temporal scale is critical for analyzing the risk of heat hazards in urban environments. The variability of urban landscapes makes cities a challenging landscape for quantifying heat exposure. Most of the existing heat hazard studies have inherent limitations on two fronts: the spatial-temporal granularities are too coarse and the ability to track the actual ambient air temperature instead of land surface temperature. Overcoming these limitations requires radically different research approaches, both the paradigms for collecting the temperature data and developing models for high-resolution heat mapping. We present a comprehensive approach for studying urban heat hazards by harnessing a high-quality hyperlocal temperature dataset from a network of mobile sensors and using it to refine the satellite-based temperature products. We mounted vehicle-borne mobile sensors on thirty city buses to collect high-frequency (5 sec) temperature data from June 2018 to Nov 2019. The vehicle-borne data clearly show significant temperature differences across the city, with the largest differences of up to 10℃ and morning-afternoon diurnal changes at a magnitude around 20℃. Then we developed a machine learning approach to derive a hyperlocal ambient air temperature (AAT) product by combining the mobile-sensor temperature data, satellite LST data, and other influential biophysical parameters to map the variability of heat hazard over areas not covered by the buses. The machine learning model output highlighted the high spatio-temporal granularity in AAT within an urban heat island. The seasonal AAT maps derived from the model show a well-defined hyperlocal variability of heat hazards which are not evident from other research approaches. The findings from this study will be beneficial for understanding the heat exposure vulnerabilities for individual communities. It may also create a pathway for policymakers to devise targeted hazard mitigation efforts such as increasing green space and developing better heat-safety policies for workers.
Upgrade of the “ActiveTectonics” on-line database of Pliocene-Quaternary fautls in the Baikal Region and adjacent areas
Authors: Gladkov Anton , Oxana Lunina
Published: March 2020

Studying and mapping of faults in the Earth’s crust is one of the priority objectives in structural geology and tectonophysics. Generally, faults are associated with mineral deposits, thermal springs, and earthquakes, and fault zones are areas of the most dangerous geological processes and various geophysical anomalies. In this regard, databases of faults are highly demanded by both science and practical applications. In this work, we present an on-line geospatial database containing faults, which were active in the Pliocene‐Quaternary within the territory between 96–124°E to 49–58°N. The locations of the faults were mapped with using MapInfo GIS based on the extensive analysis of cartographic, published and own structural materials. The data about each fault were input via ActiveTectonics Information System developed by us. The interactive version of the database put out in the open (http://www.activetectonics.ru/) in Russian and English and anyone may get available information about a fault by a click. The geoportal is constantly developing and constitutes a base for the creation of an automated system for modeling geological hazards (seismic soil liquefaction, secondary rupturing, subsidence and slope processes) in the Baikal region.

Currently, as part of the modernization of the ActiveTectonics geographic information product, we are developing models and schemes of data and metadata to create a detailed geospatial database of seismogenic ruptures of the Baikal region. A modern user-friendly interface is being developed to automate the data collection process.

The creation of such a publicly accessible catalog of seismogenic ruptures will be useful for applied and fundamental research.

The reported study was partly funded by RFBR and the Government of the Irkutsk Region, project number 20-45-385001.
Size-dependent organo-mineral interactions and dynamics in a seasonally-flooded wetland
Authors: Afsar Mohammad , Vasilas Bruce , Jin Yan
Published: March 2020

Understanding the mechanisms governing the composition and stability of organo-mineral associations is critical to predicting the dynamics of soil organic matter (SOC) and the related global carbon cycling. Redox-induced biogeochemical transformations are the key processes that control the stabilization of SOC via association with metal oxides in terrestrial environments such as wetlands. Despite its high C content (20-30% of terrestrial C), size-dependent organo-mineral associations and their dynamic changes in the redox-dynamic wetlands are poorly understood. Here we present size distribution, concentration, and composition of organo-mineral associations in pore water samples from a depressional wetland located at the Delmarva Bay in Delaware, USA, as influenced by seasonal fluctuations in water table level. The samples were collected from piezometers installed at multiple depths (50 cm, 100 cm, and 200 cm) and in three zones (upland, transitional, and wetland), respectively. Four size fractions were analyzed: dissolved (<2.3 nm), natural nanoparticle (2.3-100 nm, NNP), fine colloid (100-450 nm), and particulate (450-100 nm). Our results revealed that dissolved, NNP, fine colloid and particulate fractions comprised 47 ± 4%, 37 ± 4%, 8 ± 3% and 8 ± 3% of  the bulk organic C (<1000 nm) concentration, respectively. Relative percentages of respective Al, Mn, and Fe were 47 ± 24%, 30 ± 22%, 50 ± 18% at 2.3-450 nm and 22 ± 16%, 17 ± 12%, 25 ± 19% at 450-1000 nm size fraction. The main finding from this study are 1) dissolved and NNP fractions contain higher amount of C than colloidal and particulate fractions and 2) organo-mineral associations have significant differences in their elemental concentrations among different size fractions within colloidal size range. Additionally, the results clearly indicate that the commonly used operational definition for dissolved organic matter (DOM, <450 nm) significantly overestimates the dissolved phase C concentration by including the NNP and colloidal fractions, which contain mineral-associated C. This has important implications in the estimation of SOC decomposition rate in soils, particularly in redox sensitive wetlands, thus in assessing terrestrial C cycling and the transport of OC as well as the associated elements.
Recycling of Polyphosphate accumulated in picoplankton in coastal Lake Ontario
Authors: Dittrich Maria , Li Jiying , Diane Plouchart Diane , Zastepa Arthur
Published: March 2020

Phytoplankton can accumulate polyphosphate (polyP) to alleviate the limitation of essential nutrient phosphorus (P). Yet polyP metabolisms in aquatic systems and their roles in P biogeochemical cycle remain elusive. Previously reported polyP enrichment in low-phosphorus oligotrophic marine waters contradicts the common view of polyP as a luxury P-storage molecule. Here, we show that in a P-rich eutrophic bay of Lake Ontario, planktonic polyP is controlled by multiple mechanisms and responds strongly to seasonal variations. Plankton accumulates polyP as P storage under high-P conditions via luxury uptake and uses it under acute P stress. Low phosphorus also triggers enrichment of polyP that can be preferentially recycled to attenuate P lost. We discover that picoplankton, despite their low production rates, are responsible for the dynamic polyP metabolisms. Picoplankton store and liberate polyP to support the high primary productivity of blooming algae. PolyP mechanisms enable and P exchange and efficient P recycling on the ecosystem and even larger scales.
Effects of stemflow on infiltration flux of rainwater and dissolved Cs-137 to forest soil
Authors: Iida Hikaru , Kato Hiroaki , Shinozuka Tomoki , Akaiwa Satoru , Yokoyama Tatsuya , Hudson Sean , Hudson Janice , Onda Yuichi
Published: March 2020

Stemflow takes important role on the hydrological and chemical cycling in the rhizosphere because it brings intensive rainwater input to forest soil and enhances downward infiltration of rainwater along tree root network to deep soil horizon. However, there are few studies on the effects of stemflow in rainwater infiltration mechanisms by collecting of soil water. In this study, stemflow and soil water near the tree roots (Rd : root downslope) and far from the trunk (Bt : between trees) are collected from a cedar forest in Namie Town, Fukushima Prefecture, Japan. Samples were collected from June 24 to December 11, 2019 with a total precipitation of 1100 mm during the period. Water volume and dissolved 137Cs concentration drived from the Fukushima Dai-ichi Nuclear Power Plant accident were measured. As a result, Rd which is located in neighbor of the trunk showed greater water infiltration flux and high dissolved 137Cs concentration. The average amount of infiltration water which was normalized for open rainfall depth during the whole sampling period was 1.4 times and 3.0 times larger at 5 cm and 20 cm depth for the Rd than the Bt, the average dissolved 137Cs concentration was 1.3 times and 1.7 times larger at 5 cm and 20 cm depth, respectively. This suggests that infiltration water flux and dissolved 137Cs concentration can be increased due to contribution of stemflow input at the base of tree trunk. To determine the role of stemflow on rainwater infiltration flux and the concentration of dissolved elements in the rhzosphere, further analysis is required to clarify detailed infiltration mechanisms by using multiple tracer techniques such as stable isotopic composition of water and by collecting root oriented preferential flow.
Effects of dynamic factors of erosion on soil nitrogen and phosphorus loss under freeze-thaw conditions
Authors: cheng yuting , li peng , Xu Guoce , zhang yixin
Published: March 2020

Soil erosion is one of the primary environmental problems in China, and it can lead to serious water, soil, and nutrient losses. However, the mechanism of action of the dynamic factors of erosion on nitrogen (N) and phosphorus (P) loss remains unclear. In this study, a series of laboratory experiments were carried out to characterize the N and P loss and its influencing factors under freeze–thaw conditions. Two slope treatments (i.e. LS: loess and FTS: freeze–thaw soil) and five soil water content (SWC) (i.e. 10%, 15%, 20%, 25% and 30%) were considered. The results showed that the total runoff was higher under 30% SWC and lower under 20% SWC for the LS and FTS treatments. The freeze–thaw action caused higher sediment loss under low water content (10% and 15%). The runoff-associated total nitrogen (RTN), runoff-associated total phosphorus (RTP), and sediment-associated total phosphorus (STP) loss rate showed a larger fluctuation for FTS than for LS. The freeze–thaw action not only caused the instability of the nitrogen and phosphorus loss behavior but also caused increased diversity among individual samples. The soil erodibility, runoff energy, and runoff power were important dynamic factors associated with erosion, and the freeze–thaw action has a very large impact on these factors. For the LS treatments, the SWC could explain 60% of the variation in RTN loss and 63% of the variation in RTP; the runoff and infiltration both explained 90% of the variation in STN loss and the runoff time explained 97% of the variation in STP. For the FTS treatments, the runoff time explained 63% of the variation in STN and 53% of the variation in STP. The results enable us to understand further the relationship between dynamic factors of rainfall erosion and nitrogen and phosphorus loss under freeze–thaw conditions.
Exploring Mechanisms and Conditions for the Generation of Self-propagating Dykes
Authors: Wallner Herbert , Schmeling Harro
Published: March 2020

Within the scope of our project “Modelling melt ascent through the asthenosphere-lithosphere-continental crust system: Linking melt-matrix-two-phase flow with dyke propagation” it is necessary to implement mechanisms with appropriate conditions to generate dykes which are propagating independently.

Conditions for self-propagating depend on the density contrast of melt and rock and the geometry of the fracture. Certain limits for the fluid-filled volume and dyke width must be reached. The height must be longer than the Bouguer length. To satisfy these conditions enough melt under overpressure must be available in the source region to supply the growing dyke.

A known and accepted mechanism for dyke generation is a tension fracture whichs opening space immediately is filled by fluid melt. The normal stress due to expansion of the magma on the wallrock causes tension therein parallel to the melt front. In brittle material the yield stress for extension is very low and the confining cold rock easily cracks.

With depth pressure, temperature and ductility of crustal rock and consequently the yield stress for the tensile cracking increases. Furthermore, the background permeability or connectivity, and finally the height of fluid columns decrease and the fluid overpressure is not high enough to exert matrix extension. Another dyke initiation mechnism must be found for the deeper parts of the crust.

A not smooth melt front - and pillows are often seen on top of magma chambers – provides shear stresses and stress concentrations. Above a certain yield stress for shear failure shear bands start to evolve. In such a network of fracture zones permeability should increase. Melt may intrude, coalesce bands and develop a growing dyke. Such a local scenario will be modelled and results presented. A further aim is the parametrisation of these mechanisms.
Statistical Approaches for Modeling Ice Sheet Interconnectivity
Authors: Martinez Andrew , Jackson Luke , Pretis Felix , Juselius Katarina
Published: March 2020

The greatest sources of uncertainty for future sea-level rise are the Greenland and Antarctic ice sheets. An important aspect of this uncertainty is the potential interconnectivity between them, which may amplify underlying instabilities in individual ice sheets. We explore these connections empirically by modelling the ice sheets as a cointegrated system. We consider two specications which allow the ice sheets to follow either an I(1) or an I(2) process in order to disentangle the long-run theory consistent relationships in the data. We examine the stability of these relationships over time both in and out of sample and eximine how a sudden loss of ice in Greenland propagates through the system. We show that a 1 Gigatonne loss of ice leads to a large and persistent loss of ice in West Arctica which is partially offset by an accumulation of ice in East Antarctica. Accounting for the long-run interactions between the ice sheets helps to improve our understanding of future instabilities and provides useful projections of the future paths of the ice sheets.
Orographic modulation and elevation dependence of regional fine scale precipitation change signals - European examples
Authors: Torma Csaba Zsolt
Published: March 2020

High number of regional climate model (RCM) experiments have been accomplished over different subregions of the globe in the framework of the international initiative called the COordinated Regional Downscaling Experiment (CORDEX). Being the European branches of the CORDEX program: EURO-CORDEX and Med-CORDEX provide RCM simulations targeting Europe at grid resolutions of 0.11°. Investigation of ensembles of driving GCM and nested RCM simulations for the late 21st century with respect to late 20th century from the CMIP5, EURO-CORDEX, and Med-CORDEX experiments are presented at high resolution, with a special focus on mountainous regions such as the Alps and the Carpathians. Present work gives an overview on how the fine-scale RCM downscaling can modulate the GCM-produced precipitation change signal in future climate projections over the regions of interest. Our findings point to the fact that the topographically induced fine scale precipitation signal is mostly of dynamical nature in winter, while is more thermodynamic in nature during summer which manifests in strong elevation dependence, thus the high-resolution representation of topography in climate models is crucial for the provision of fine scale precipitation projections in mountainous regions.
The need for global glacier speed to combine measured velocity with balance velocity
Authors: Jiskoot Hester , DeJong Easton , Van Wychen Wesley , Cooley Jade
Published: March 2020

One of the outstanding glaciological research questions is how glaciers respond dynamically to climate change and how this varies regionally. Ice-velocity changes occur on an interannual scale in response to mass-balance forcing changing the glacier geometry and therefore the driving stress. For a glacier tending towards steady-state the mass flux through a cross-section equals the mass balance upstream of the cross-section. Mass loss will, therefore, usually lead to a slowdown of glaciers. However, a changing climate can also affect the occurrence of sliding and change a glacier’s thermal regime and its marginal processes (ice-ocean, ice-lake and ice-bed interactions). The response of glacier flow to climate change is, therefore, not straightforward, and mass loss combined with increased meltwater production or a transition to a temperate regime may lead to an increase in flow speed. Ultimately, depending on their individual response time, glaciers respond in a delayed dynamical way to changes in mass balance.

Various recent publications have addressed the above research question at regional scales by analysing decadal changes in flow speed in relation to glacier mass loss. Only few local works, however, have addressed the question in the context of measured differences between actual and balance velocities. The recent generation of diverse global glacier datasets, such as the Randolph Glacier Inventory (RGI), GoLIVE and ITS_LIVE ice speed, ice thickness, and globally-distributed datasets such as WGMS mass balance data and companion ground measurements, offer opportunities to address outstanding research questions in interregional to global perspectives. We will compare, for the first time, for glaciers in various RGI subregions the difference between the measured glacier velocity, derived from available GoLIVE and ITS-LIVE datasets and additional speckle tracking from SAR scenes, and the balance velocity, derived using mass balance profiles, hypsometry, and ice thickness datasets. We use the standard approach of deriving balance flux along a flowline, and use a scenario-based approach to deal with measurement and model uncertainties. In this poster we present the results for approximately 20 glaciers in Canada and Iceland in detail. Ultimately, we aim to use more than 200 glaciers with WGMS and independent long-term mass balance records, distributed over the 19 RGI first-order regions and as many as the 89 second-order regions as possible.
Numerical simulation of steady state groundwater flow field in discretely fractured rocks using the Green element method with the concept of multiple interacting normal flux
Authors: Liou Tai-Sheng
Published: March 2020

Numerical simulation is an effective tool for estimating the groundwater flow field in discretely fractured rocks (DFR). Unlike most numerical simulation methods that require the discretization of the model domain, boundary element method (BEM) is renowned of waiving the spatial discretization task but focusing on solving the integral form of the governing groundwater flow equation. However, for groundwater flow simulation in DFR, the solution obtained by BEM tends to have large error in the vicinity of fracture intersection. Therefore, a new numerical scheme, the green element method (GEM) is adopted in this study. GEM is built on the same mathematical background as BEM but turns the domain discretization back on as a necessary task. Using the second Green’s identity, GEM produces a general equation that applies to each grid block by integrating the governing equation. By making use of the singular characteristic of the Green’s function, GEM transforms the integral equation into a discretized system of equations with nodal head or nodal head gradient as unknowns. The cost of discretizing the model domain is compensated by the convenience of handling the heterogeneity of the medium. Conventional GEM manages the normal flux across a boundary segment by differentiating head values from 2 nodes in an individual grid block. This approximation overlooks the mechanism of normal flux as the exchange of fluid mass between grid blocks. To take this mechanism into consideration, a modified model of normal flux is proposed if the fracture plane is discretized into triangular elements. This model expresses the normal flux across a grid boundary segment in terms of the difference of head values in two grid blocks that are connected to this segment. For convenience, the head value at the centroid of a triangular element is used to calculate the normal flux. In other words, the unknowns of a triangular element are three nodal heads plus one centroidal head. Thus, the modified normal flux will be able to consider the interaction of all grid blocks that are connected to a target grid block. More importantly, the resulting global coefficient matrix is a square one and the system of equations is closed. The solution obtained from the closed system of equations will be exact but not a least-square approximated one. This modified GEM will be applied to simulate the steady state groundwater flow field in discretely fractured rocks.
Interhemispheric conjugate effect in longitude variations of mid-latitude ion density
Authors: Chen Yiding , Liu Libo , Le Huijun , Zhang Hui
Published: March 2020

Interhemispheric coupling between the northern and southern mid-lattitude ionosphere through the plasmasphere is difficult to confirm directly from observations. A possible result induced by this coupling is interhemispheric conjugacy of the mid-latitude ionosphere. In this paper, interhemispheric conjugate effect in longitude variations of mid-latitude total ion density (Ni) is presented, for the first time, using the Defense Meteorological Satellite Program (DMSP) measurements; northern and southern Ni longitude variations at 21:30 LT are similar between magnetically conjugate mid-latitudes around solar minimum June Solstice of 1996. The conjugate effect after sunset also occurs around the June Solstice in other solar minimum years but disappears when solar activity increases. We suggested that mid-latitude interhemispheric coupling is responsible for the conjugate effect. Neutral wind induced ionospheric transport causes topside longitude variations via upward diffusion at summer mid-latitudes; this further induces similar longitude variations of topside Ni at winter mid-latitudes via the summer to winter interhemispheric coupling. The conjugate effect occurs only inside the plasmapause where magnetic flux tubes are closed and the plasma in these tubes can stably corotate with the Earth. The conjugate effect not only proves mid-latitude interhemispheric coupling through the plasmasphere, but also implies that neutral wind induced transport can affect ionospheric coupling to the plasmasphere at mid-latitudes.
Reducing Water Scarcity by Improving Water Productivity
Authors: Marston Landon , Lamsal Gambhir , Ancona Zachary , Caldwell Peter , Richter Brian , Ruddell Benjamin , Rushforth Richard , Davis Kyle
Published: March 2020

Nearly one-sixth of US river basins are unable to consistently meet societal water demands while also providing sufficient water for the environment. Water scarcity is expected to intensify and spread as populations increase, new water demands emerge, and climate changes. Improving water productivity by meeting realistic benchmarks for all water users could allow US communities to expand economic activity and improve environmental flows. Here we utilize a spatially detailed database of water productivity to set realistic benchmarks for over 400 industries and products. We assess unrealized water savings achievable by each industry in each river basin within the conterminous US by bringing all water users up to industry- and region-specific water productivity benchmarks. Some of the most water stressed areas throughout the US West and South have the greatest potential for water savings, with around half of these water savings obtained by improving water productivity in the production of corn, cotton, and alfalfa. By incorporating benchmark-meeting water savings within a national hydrological model (WaSSI), we demonstrate that depletion of river flows across Western US regions can be reduced on average by 6.6%-23.5%, without reducing economic production. Lastly, we employ an environmentally-extended input-output model to identify the US industries and locations that can make the biggest impact by working with their suppliers to reduce water use “upstream” in their supply chain. The agriculture and manufacturing sectors have the largest indirect water footprint due to their reliance on water-intensive inputs but these sectors also show the greatest capacity to reduce water consumption throughout their supply chains.
Subsidence discrepancy in the Valencia Trough revealed from reflection seismic observations and backstripping results
Authors: Fang Penggao , Mohn Geoffroy , Tugend Julie , Kusznir Nick
Published: March 2020

    The Valencia Trough is commonly included as part of the set of western Mediterranean Cenozoic extensional basins that formed in relation with the Tethyan oceanic slab rollback during the latest Oligocene to early Miocene. It lies in a complex tectonic setting between the Gulf of Lions to the North-West, the Catalan Coastal Range and the Iberian chain to the West, the Balearic promontory to the East and the Betic orogenic system to the South. This rifting period is coeval with or directly followed by the development of the external Betics fold and thrust belts at the southern tip of the Valencia Trough. Recent investigations suggest that the Valencia Trough is segmented into two main domains exhibiting different geological and geophysical characteristics between its northeastern and southwestern parts. The presence of numerous Cenozoic normal faults and the well-studied subsidence pattern evolution of the NE part of the Valencia Trough suggest that it mainly formed coevally with the rifting of Gulf of Lion. However, if a significant post-Oligocene subsidence is also evidenced in its SW part; fewer Cenozoic rift structures are observed suggesting that the subsidence pattern likely results from the interference of different processes.

    In this presentation, we quantify the post-Oligocene subsidence history of the SW part of the Valencia Trough with the aim of evaluating the potential mechanisms explaining this apparent subsidence discrepancy. We analyzed the spatial and temporal distribution of the post-Oligocene subsidence using the interpretation of a dense grid of high-quality multi-channel seismic profiles, also integrating drill-hole results and velocity information from expanding spread profiles (ESP). We used the mapping of the main unconformities, especially the so-called Oligocene unconformity, to perform a 3D flexural backstripping, which permits the prediction of the post-Oligocene water-loaded subsidence. Our results confirm that the post-Oligocene subsidence of the SW part of the Valencia Trough cannot be explained by the rifting of the Gulf of Lions. Previous works already showed that the extreme crustal thinning observed to the SW is related to a previous Mesozoic rift event. Here, we further highlight that if few Cenozoic extensional structures are observed, they can be interpreted as gravitational features rooting at the regionally identified Upper Triassic evaporite level. Backstripping results combined with the mapping of the first sediments deposited on top of the Oligocene unconformity show that they are largely controlled by the shape of Betic front with a possible additional effect of preserved Mesozoic structures. At larger scale, we compare the mechanisms accounting for the origin and subsidence at the SW part of the Valencia Trough with those responsible for the subsidence of its NE part and the Gulf of Lions.
SWAT-based sediment yield simulation with mining land-use change scenario in Lanuza Bay, Philippines
Authors: Maloles Peter Jeffrey , Gallentes Adonis , Villanoy Cesar
Published: March 2020

The Philippines is known for its rich marine biodiversity and is deemed as the apex of the world’s coral triangle. However, sediment yield studies and river discharge measurements in the country are sparse if not non-existent. High sediment rates have detrimental effects on water quality and consequently to coral reef health and marine biodiversity. Thus, modeling of runoff and sediment yield at a watershed level is important in assessing coral community environments.

In this study, a Soil and Water Assessment Tool (SWAT) based sediment yield simulation was done for Lanuza Bay-- a site with high productivity but increasing mining activity. Two simulations were conducted. The first utilized a land-use map before January 2011 and was made to run from January 1998 to August 2018 in order to simulate a scenario in which mining operations did not occur in the area. The second simulation utilized an updated land-use map that incorporated mining sites from January 2011 to August 2018.

SWAT model results indicate that slope class was the primary determinant of erosion rates (slope band > 20%). The study suggests that consecutive precipitation occurrences affected soil erodability and induced a time lag between precipitation and sediment yield peaks. The highest contributors to sediment yield at a sub-basin level were identified to be areas adjacent to or coinciding in mining or excavation sites. Comparing the scenarios with and without mining, mining contributed to 4% of the increase in the watershed’s total annual sediment yield.

Qualitative and historical validation shows reasonable agreement between simulated values and satellite images. The output of this study can be used as a science-based reference in crafting laws and policies for land-use management and Marine Protected Area (MPA) planning.
World’s potential energy production from microalgae on marginal land
Authors: Zhang Qingtao
Published: March 2020

Petrochemical fuel usage abuse has caused the depletion of oil reservoirs and increasing environmental problems such as greenhouse gas emission and global warming. Therefore, it is necessary to develop greener and sustainable alternatives. Carbon dioxide is the main contributor to the global warming crisis. Biomass energy has received the most attention in many integrated assessment model studies and the latest IPCC reports. Among various existing carbon capture technologies, microalgae-based biological carbon capture is one of the promising and lower energy consumption technologies.

 

Microalgae rise as 3rd generation bioenergy feedstock due to its attractive higher carbon dioxide fixation efficiency, higher biomass productivity, and relatively easy pretreatment processes for various biofuel extractions. Besides, microalgae have a low demand for water quality and soil fertility compared to traditional energy plants. It means growing microalgae on the marginal land (non-fertile land that is not suitable for agriculture) could be a promising agent for bioenergy production and CO2 mitigation.

 

The study is aimed to evaluate the potential energy production from microalgae on marginal land. We combined geospatial data with climate, soil, and terrain to estimate the marginal land of each country. By using Williams and Laurens’ model (2010), we calculated the annual microalgae areal biomass yields for different latitudes and evaluated annual potential energy production from microalgae on marginal land. It is estimated that microalgae may generate up to 67.9 billion tons of coal equivalent of potential energy per year on the total marginal land. By replacing fossil fuels, there will be emission reduction potential 290.6 billion tons of carbon dioxide.
Biomarker (brGDGT) degradation and production in lacustrine surface sediments: Implications for paleoclimate reconstructions.
Authors: De Jonge Cindy , Fiskal Annika , Han Xingguo , Lever Mark
Published: March 2020

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a class of biomarker lipids that can be conserved over long timescales in lake sediments. Produced throughout the lake water column before settling and incorporation in the sedimentary archive, they are used to reconstruct lake water temperature changes through time. However, it is not clear how degradation and/or production of these compounds in the surface sediments influences the brGDGT signal and the reconstructed temperature record.

Here we present the core lipid (“fossil”) and intact polar lipid (“recently produced”) signal of brGDGT lipids in 8 short cores collected in 4 Swiss lakes, covering a eutrophic gradient. In eutrophic conditions (Lake Baldegg), a clear subsurface (20-35 cm blf) maximum in intact polar lipids is observed (15-20%), whereas the most surficial sediments (0-2 cm blf) show the lowest percentage of IPL lipids (<5%). Our data indicates that tetramethylated brGDGT lipids are produced in the subsurface. As the bacterial community has been reconstructed in all cores, using 16S rRNA gene distribution, we observe that this production is coeval with an increase in the relative abundance of OTUs in the phyla Acetothermia, Aminicenantes, Caldiserica and Spirochaetes. Hexamethylated brGDGTs are encountered in increased amounts in most surficial sediments (0-2 cm bsf), but are degraded further downcore. Both degradation and in-situ production cause the reconstructed temperatures based on the surface sediments to be 2 ℃ colder than those from the subsurface.

In sediments where degradation and subsurface production of brGDGT lipids occurs, this has the potential to impact paleoclimate reconstructions. A colder MBT’5ME signal in surface sediments has indeed been observed in several studies (i.e. Tierney et al., 2012; Miller et al., 2018, Martin et al., 2020). Furthermore, a distinct brGDGT signal in surface sediments has a possible impact on existing lacustrine calibration datasets, as these are based on surface sediments.

References:

Tierney et al. (2012), GCA 77, p561-581. Miller et al. (2018), CoP 14 (11), p1653-1667. Martin et al. (2020), QSR 228, 106109.
Making ethics codes more effective
Authors: Boon Jan
Published: March 2020

Many businesses and organizations of all types have adopted ethics codes or codes of conduct. Examples relevant to geoscience include the Cape Town Statement on Geoethics of the International Association for Promoting Geoethics,  the Scientific Integrity and Professional Ethics policy of the American Geophysical Union, and the Joint EGU-AGU Statement of principles for a  code of ethics for the geosciences. The Government of Canada is implementing a Science Integrity Policy across its science-related Departments. Successful implementation of such policies can be challenging and many breaches have been and continue to be reported. Humans make ethical or unethical decisions and understanding the sociological processes that are involved and applying this knowledge to the implementation of ethics codes may improve their success rates. This paper analyzes these sociological processes through the lens of symbolic interactionism theory. In spite of its somewhat forbidding name, the theory is actually quite simple. It shows how interactions between people lead to the meanings they give to other people, organizations and things. It describes how these meanings lead to the interpretation of situations, and how groups arrive at normative decisions based on this interpretation. These normative decisions involve ethical considerations. The paper describes the approach and seeks audience feedback on a proposed survey of the members of the International Association for Promoting Geoethics  to collect empirical evidence on which to base a symbolic interactionist approach to effective implementation of ethics codes in geoscience.
Vegetation feedbacks during drought exacerbate ozone air pollution extremes in Europe
Authors: Lin Meiyun , Horowitz Larry , Xie Yuanyu , Paulot Fabien , Malyshev Sergey , Shevliakova Elena , Finco Angelo , Gerosa Giacomo , Kubistin Dagmar , Pilegaard Kim
Published: March 2020

This study highlights a previously under-appreciated “climate penalty” feedback mechanism - namely, substantial reductions of ozone uptake by water stressed vegetation – as a missing piece to the puzzle of why European ozone pollution episodes have not decreased as expected in recent decades, despite marked reductions in regional emissions of ozone precursors due to regulatory changes. The most extreme ozone pollution episodes are linked to heatwaves and droughts, which are increasing in frequency and intensity over Europe, with severe impacts on natural and human systems. Under drought stress, plants close their stomata to reduce water loss, consequently limiting the ozone uptake by vegetation (a component of dry deposition), leading to increased surface ozone concentrations. Such land-biosphere feedbacks are often overlooked in prior air quality projections, owing to a lack of process-based model formulations. Here, we use six decades of observations and Earth system model simulations (1960-2018) with an interactive dry deposition scheme to show that declining ozone removal by water-stressed vegetation in the warming climate exacerbate ozone air pollution over Europe. Incorporated into a dynamic vegetation land – atmospheric chemistry – climate model, the dry deposition scheme mechanistically describes the response of ozone deposition to atmospheric CO2 concentration, canopy air vapor pressure deficit, and soil water availability. Our observational and modeling analyses reveal drought stress causing as much as 70% reductions in ozone removal by forests. Reduced ozone removal by water-stressed vegetation worsens peak ozone episodes during European mega-droughts, such as the 2003 event, offsetting much of the air quality improvements gained from regional emission controls. Accounting for vegetation feedbacks leads to a three-fold increase in high surface ozone events above 80 ppbv (8-hour average) and a 20% increase in the sensitivity of ozone pollution extremes (95th percentile) to increasing temperature. As the frequency of hot and dry summers is expected to increase in the coming decades, this ozone climate penalty could be severe and therefore needs to be considered when designing clean air policy in the European Union. 

Notes: This study is currently under review for possible publication in Nature Climate Change. 
Drought terminations in the UK driven by high integrated vapour transport
Authors: Parry Simon , Lavers David , Wilby Rob , Wood Paul , Prudhomme Christel
Published: March 2020

Whilst the hydroclimatic drivers of drought are well-established, the forces which lead to the termination of drought conditions are less well understood.  An enhanced knowledge of the associations between these phenomena and drought termination is an important prerequisite for more robust operational forecasting of the end of droughts, a phase which assumes critical importance during protracted droughts which can span multiple years and substantially deplete water resources.

The influence of high integrated vapour transport (IVT) on drought termination has been established in the western USA, and atmospheric rivers have been linked to the ending of droughts in the mid-latitudes including North America and Asia.  Whilst high IVT has been demonstrated to be influential in major flood events in western Europe, a potential link with drought termination has not previously been identified.

This study systematically identifies drought termination events in river flow reconstructions for 302 catchments in the UK spanning the 1900-2010 period, and assesses the correspondence with high IVT values extracted from the ERA-20C reanalysis dataset spanning the same period.  Event coincidence analysis is used to quantify this association, with the Precursor Coincidence Rate (PCR) assessing the likelihood of high IVT preceding drought termination, and the Trigger Coincidence Rate (TCR) considering how often high IVT leads to drought termination.

PCRs were moderate to high across most of the UK, indicating that in most catchments a majority of drought terminations are triggered by high IVT.  TCRs were highest in the west of the UK, suggesting that in these regions a majority of high IVT episodes during droughts lead to its termination.  The combination of prevailing direction of landfalling high IVT with upland, wet and responsive catchments in the west (and vice versa) was supported by regression analysis.  In addition to determining occurrence, high IVT was also found to be influential on the characteristics of drought termination.

Metrics of PCR and TCR have the potential to inform management decisions in drought-impacted catchments, quantifying the likelihood of termination in instances of forecast high IVT events.  The importance of establishing associations between high IVT and drought termination is underlined by the higher confidence in IVT forecasts than direct rainfall forecasts over certain medium-range lead times.