bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term variations of diffuse CO2 and H2S at the summit crater of Teide volcano, Tenerife, Canary Islands
Authors: Alonso Mar , Hoffman Harry T. A. , Smith Joseph G. , Thompson Erin , Rodríguez Fátima , Amonte Cecilia , Asensio-Ramos María , Pitti Lia , Padrón Eleazar , Pérez Nemesio M.
Published: March 2020

Tenerife (2,034 km2) is the central and largest island of the Canarian archipelago, located about 100 km west of the African coast between 27º37’ and 29º25’N and between 13º20’ and 18º10’W. The structure of Tenerife is controlled by a volcano-tectonic rift-system with NW, NE and NS directions with Teide volcano located in the intersection of the three rifts. Teide is the highest stratovolcano in the Atlantic Ocean reaching 3,718 m.a.s.l. with its last eruption occurred in 1798 through an adventive cone of Teide-Pico Viejo volcanic complex. Persistent degassing activity, both visible and diffuse, takes place at the summit cone of the volcano, being the diffuse degassing the principle degassing mechanism of Teide (Mori et. al., 2001; Pérez et. al., 2013). As part of the volcanic monitoring program of INVOLCAN in Tenerife, 8 surveys were performed during summer 2019 in order to evaluate the short term variations of diffuse CO2 and H2S emissions in the summit crater. The emissions were calculated using data from 38 sampling sites homogeneously distributed inside the crater covering an area of 6,972 m2 by means of a portable CO2 and H2S fluxmeter using the accumulation chamber method (Parkinson 1981). During the study period, CO2 and H2S emissions ranged from 33 ± 5 to 93 ± 25 t/d and from 0.6 ± 0.2 to 4 ± 0.1 kg/d, respectively. Despite the small changes observed in the temporal evolution, values are considered normal for a quiescence period in Teide volcanic system. Short term variations in CO2 and H2S emissions indicate changes in the activity of the system and can be useful to understand the behaviour of the volcanic system and as forecast of future volcanic activity.

References
Mori T. et al. (2001). Chemical Geology, 177, 85–99.
Parkinson K. J. (1981). Journal of Applied Ecology, 18, 221–228.
Pérez N. M. et al. (2013). Journal of the Geological Society, 170, 585–592.
The Extreme Weather Event Real-time Attribution Machine (EWERAM) – An Overview
Authors: Tradowsky Jordis , Bodeker Greg , Bird Leroy , Kremser Stefanie , Kreft Peter , Soltanzadeh Iman , Rausch Johannes , Rana Sapna , Rye Graham , Ziegler Andy , Rosier Suzanne , Stone Daithi , Dean Sam , Renwick James , Frame David , McDonald Adrian
Published: March 2020

As greenhouse gases continue to accumulate in Earth’s atmosphere, the nature of extreme weather events (EWEs) has been changing and is expected to change in the future. EWEs have contributions from anthropogenic climate change as well as from natural variability, which complicates attribution statements. EWERAM is a project that has been funded through the New Zealand Ministry of Business, Innovation and Employment Smart Ideas programme to develop the capability to provide, within days of an EWE having occurred over New Zealand, and while public interest is still high, scientifically defensible statements about the role of climate change in both the severity and frequency of that event. This is expected to raise public awareness and understanding of the effects of climate change on EWEs.

A team of researchers from five institutions across New Zealand are participating in EWERAM. EWE attribution is a multi-faceted problem and different approaches are required to address different research aims. Although robustly assessing the contribution of changes in the thermodynamic state to an observed event can be more tractable than including changes in the dynamics of weather systems, for New Zealand, changes in dynamics have had a large impact on the frequency and location of EWEs. As such, we have initiated several lines of research to deliver metrics on EWE attribution, tailored to meet the needs of various stakeholders, that encompass the effects of both dynamical and thermodynamical changes in the atmosphere. This presentation will give an overview of EWERAM and present the methodologies and tools used in the project.
Integrating hydrological constraints for hydropower in energy models: the case of the Zambesi River Basin in the Southern African Power Pool
Authors: Daddi Martina , Barbieri Alessandro , Castelletti Andrea , Giuliani Matteo , Colombo Emanuela , Rocco Matteo , Stevanato Nicolò
Published: March 2020

Ensuring reliable supplies of energy and water are two important Sustainable Development Goals, particularly for Sub-Saharan African countries. The energy and water challenges are however not independent, and the interlinkages between them are increasingly recognized and studied using water-energy nexus approaches. Yet, most of existing modeling tools are not accurately reproducing this nexus and thus provide limited support to the design of sustainable development plans.

In this work, we contribute an integrated modeling approach by embedding the hydrological description of the Zambesi River Basin into an energy model of the Southern African Power Pool (SAPP). The SAPP is the largest African power pool in terms of installed capacity and coordinates the planning and operation of the electric power system among the twelve member countries (Angola, Botswana, DRC, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Tanzania, Zambia, Zimbabwe). Specifically, we use the Calliope energy model, which allows to form internally coherent scenarios of how energy is extracted, converted, transported and used, setting arbitrary spatial and temporal resolution and time series input data. As in many state-of-the-art energy models, hydropower production is poorly described by neglecting the water availability constraints and assuming hydropower plant produce at their nominal capacity in each timestep. Exploiting Calliope existing modeling components, we improved the hydrological description of the main reservoirs in the Zambezi River Basin as part of the overall SAPP model, namely Ithezithezi (120 MW), Kafue Gorge (990 MW), Kariba (1.8 GW) and Cahora Bassa (2 GW). Our improvements include the most relevant hydrological constraints, such as time-varying water availability as determined by inflow patterns, time-varying hydraulic head, evaporation losses, cascade releases and minimum and maximum storage value. The model outcomes, such as the  storage timeseries of each reservoir and the power production by source of each country, are then evaluated for different hydrologic scenarios. Our results are expected to demonstrate the value of advancing the hydropower characterization in energy models by capturing reservoir dynamics and water resource availability. These improvements will be particularly valuable to support hydropower expansion in African countries that rely mostly on hydropower to satisfy their growing energy demand.
Getting the basics right: a field-teaching primer on toilet stops in the field
Authors: Giles Sam , Greene Sarah , Ashey Kate , Dunne Emma , Edgar Kirsty , Hanson Emma
Published: March 2020

Geological patterns exposed on the surface of the earth are fundamental to understanding the processes that formed and shape our world; fieldwork, therefore, underpins the geosciences and geoscience education in particular. For many students, fieldtrips are a major attraction to the geosciences. Nevertheless, for many others, fieldwork presents a barrier to studying or enjoying geoscience at university, potentially contributing to the dual diversity and recruitment crises being felt throughout the discipline. A pressing but often overlooked barrier is the issue of toilet stops and menstruation in the field. Informal surveys indicate that toileting information is rarely given to undergraduates in advance of or during fieldwork. Failure to provide adequate information causes unnecessary anxiety and stress and may lead to students managing or restricting fluid intake, with potential downstream health impacts such as urinary tract infections or dehydration. Here we present a short educational primer with recommended best practices for field-based teaching. The primer covers topics such as peeing, menstruation, and provision of sanitary supplies, as well as suggestions for inclusive itinerary development. Future work will develop this primer further by incuding critical perspectives on other issues that may increase the need for frequent toilet stops. This primer is released under a CC-BY-4.0 license to facilitate sharing amongst staff and students. It is hoped that this will go some way to minimizing stress and anxiety for all parties, ultimately contributing to more inclusive field teaching.
UAV-derived change detection without ground control points, an example from the cliff coast of Rügen
Authors: Cook Kristen , Dietze Michael
Published: March 2020

High resolution topographic models generated from repeat unmanned aerial vehicle (UAV) surveys and structure from motion (SfM) are increasingly being used to investigate landscape changes and geomorphic processes. Traditionally, accurate UAV surveys require the use of independently measured ground control points or highly accurate camera position measurements. However, in addition to accuracy in an absolute sense (how well modeled topography matches real topography), model quality can be expressed as accuracy in a comparative sense (the degree to which two models match each other). We present a simple SfM workflow for calculating pairs or sets of models with a high comparative accuracy, without the need for ground control points or a dGNSS equipped UAV. The method is based on the automated detection of common tie points in stable portions of the survey area and, compared to a standard SfM approach without ground control, reduces the level of change detection in our surveys from several meters to 10-15 cm. We apply this approach in a multi-year monitoring campaign of an 8 km stretch of coastal cliffs on the island of Rügen, Germany. We are able to detect numerous mass wasting events as well as bands of more diffuse erosion in chalk sections of the cliff. Both the cliff collapses and the diffuse erosion appear to be strongly influenced by antecedent precipitation over seasonal timescales, with much greater activity during the winter of 2017-2018, following an above average wet summer, than during the subsequent two winters, which both followed relatively dry summers. This points to the influence of subsurface water storage in modulating cliff erosion on Rügen.
Precise ground-based GNSS-reflectometry water level measurements using multiple low-cost antennas
Authors: Purnell David , Gomez Natalya , Minarik William , Langston Gregory
Published: March 2020

GNSS-Reflectometry (GNSS-R) is a promising new technique to monitor water levels due to easier and cheaper installation of instruments in remote environments compared to traditional acoustic sensors or pressure gauges. GNSS stations that have been used for reflectometry purposes thus far are designed for monitoring land motion and may cost more than 10,000 USD each. We have found that a low-cost GNSS antenna and receiver (10 USD) can be used to make equally precise water level measurements, with an RMSE of a few centimeters when compared to a collocated acoustic sensor. However, an RMSE of less than one centimeter is typical for water level sensors and this level of accuracy is desired for research purposes. Two of the dominant sources of error in GNSS-R measurements are the effects of random noise in the Signal-to-Noise Ratio (SNR) data and tropospheric delay. Modelling work suggests that these sources of error can be reduced by using multiple low-cost antennas in the same location. In light of this, we have installed an experimental setup of antennas at various locations along the Saint Lawrence River and Initial results show that multiple antennas can be used to provide more precise measurements than a single antenna. Our installations of multiple antennas are less than 5% of the cost of stations that have been used in previous GNSS-R literature. Hence this approach could be applied to install a dense network of water level sensors along rivers, lakes or coastlines at a relatively low cost. We expect that this approach could also be applied to GNSS-R soil moisture or snow depth measurements.
Improving assessments of forest carbon cycling by integrating terrestrial LiDAR with dendrochronological and flux tower data
Authors: Karamihalaki Maria , Wei Jingshu , Marty Mauro , Babst Flurin
Published: March 2020

As the societal need to mitigate anthropogenic CO2 emissions aggravates, scientists are challenged to improve climate projections, which in turn calls for better estimates of terrestrial carbon (C) stocks and fluxes. In order to meet this growing demand, we are developing a novel methodology for the production of precise annually-resolved C estimates in forest ecosystems, by integrating Terrestrial Laser Scanning (TLS), flux-tower data, forest inventories, and tree-ring measurements. By coupling C estimates in the sampling year with radial growth and wood density data from tree cores, we are able to precisely reconstruct forest biomass in mature forest stands across Europe and create new insight into historical C dynamics. Here, we present our first results of biomass estimates in a Fagus sylvatica dominated tree stand in Hainich National Park, Thuringia, Germany. We provide an overview of the methodology that was developed for the extraction of biomass information from TLS point clouds. Furthermore, we discuss the challenges introduced at different processing steps and highlight the opportunities that the TLS provides for C cycle research. Ultimately, we aim at reducing uncertainties in the scaling of annual C stock changes and at advancing our understanding of C cycling in temperate forests. We expect that this information will create a refined empirical baseline for vegetation (and by extent climate) model parameterization across multiple spatiotemporal domains and thus improve our understanding of carbon sink trajectories and carbon allocation dynamics and drivers in temperate forests.
The Impact of Charcoal Production for Energy on Tropical Rainforest Resources in Nigeria
Authors: Lansu Angelique , Bos Jaap , Ivens Wilfried
Published: March 2020

In Sub Saharan Africa, many people depend on biomass for their household energy. Charcoal production is a common technique for converting biomass into a useful energy source. Nigeria is the biggest charcoal producer in Sub Saharan Africa. A large amount of wood is harvested from Nigerian forests for this charcoal production for energy. The Nexus of charcoal-land use change-energy imposes a considerable burden on the amount of wood that must be extracted from the forest for charcoal production. Therefore, charcoal production is linked to deforestation and forest degradation. However, it is not clear to what extent the demand for charcoal in Nigeria contributes to deforestation by land use change, and degradation of forests by selected wood logging. In this study, an attempt was made to provide an answer to this and to state which situation could occur by 2030, following the expected population growth in Nigeria. To achieve this, literature and open data on charcoal production, deforestation, forest degradation and population growth in Nigeria have been collected and analysed. Subsequently, calculations were carried out to determine to what extent charcoal production contributed to deforestation in the period 1990-2015. In this period, the share of deforestation due to charcoal production increased from 6% to 14%. If the expected charcoal production in 2030 were to apply to the current situation, this share would be around 20%. The quantity of wood required can also be expressed in numbers of hectares with biomass. In that case, around 80,000 ha would be required in 2030. To validate the findings, further research is needed on the amount of biomass per hectare in Nigerian forests, and on the amount of charcoal exported, not only as source of household energy but also globally as barbecue fuel. A more extensive analysis of open data on the nexus charcoal-land use change-energy at multiple scales will help to project future interlinkages.
Geophysical Exploration of the Dynamics and Evolution of the Solar System (GEODES)
Authors: Schmerr Nicholas , Richardson Jacob , Ghent Rebecca , Siegler Matthew , Young Kelsey , Montési Laurent ,   The GEODES Team
Published: March 2020

The Moon, near Earth asteroids, and the martian moons Phobos and Deimos are all Solar System Exploration Research Virtual Institute (SSERVI) target bodies as they present a wide variety of natural wonders and are potential hosts to resources that will one day enable human exploration of the Solar System. Our SSERVI project, Geophysical Exploration of the Dynamics and Evolution of the Solar System (GEODES) is exploring a suite of natural resources on these bodies through multidisciplinary geophysical investigations. Geophysical methods have been incredibly successful in identifying resources on Earth as they provide a means of characterizing and mapping the sub-surface using data gathered on and above the surface. We focus our geophysical investigations on four essential resources that will enable future human space exploration: I) Lava tubes and void spaces, capable of hosting people and infrastructure; II) Ice deposits, subsurface bodies that can be used for volatile extraction; III) Regolith, which covers the surface of all target bodies, potentially serving as a building material but also presenting a hazard to human and robotic operations and health; and IV) Magma-tectonic Systems, which mobilize, concentrate, and trap volatiles, unique rocks, and ore minerals.

Our investigations use an "orbit to outcrop" approach by analyzing existing geophysical data, conducting geophysical exploration of field analog sites on Earth, and creating models that link these analog studies to SSERVI target bodies. Analog sites enable the development, ground-truthing, and integration of (a) exploration strategies, (b) multiple geophysical methods, and (c) modeling capabilities. The GEODES team is integrating field methods and results to create a scientific modeling framework that facilitates the joint inversion of data sets and will share these results with the community via cyber infrastructure, data management, and outreach. The unifying goal behind GEODES is to develop geophysical detection and exploration methods to characterize these natural resources and enable in situ resource utilization at SSERVI target bodies.
The impacts of urbanisation on urban soil carbon – a study from Manchester, UK
Authors: ORiordan Roisin , Davies Jess , Stevens Carly , Quinton John , Boyko Christopher
Published: March 2020

The study of anthropogenic soils is a growing area of interest, and as cities continue to expand, urban soils are heavily influenced by human activities. Urbanisation exhibits a wide range of impacts on soil, from buried horizons, compaction, sealing with impervious surfaces, additions of anthropogenic material to being largely man-made soils, or technosols. The properties of urban soil are further complicated by the addition of fertilisers, management strategies in greenspaces and the treatments of soil, including topsoil removal, during construction projects. Therefore, the properties and functions of anthropogenic soils differ notably to that of natural soils, and as such, there is a need to understand the dynamics of soil carbon in urban areas.

Research on urban soil carbon has been relatively limited, however there is recent growth in this area due to its importance, firstly, as a carbon store contributing to climate regulation, and secondly, in relation to the potential of urban soil to support numerous ecosystem services. Urban soils are highly heterogeneous and anthropogenic carbon additions can come from many current or historical sources, such as charcoal used in old roads, coal ash from power stations, carbon from car tyres, as well as inorganic carbonates in limestone road foundations. Understanding the current stores of carbon, as well as how stable it is, is important to understand likely carbon dynamics and storage potential.

This work presents a field study across Manchester (UK) where soil carbon data has been collected from soils across urban parks, greenspaces and from under sealed surfaces (roads and pavements). It provides carbon data for a variety of urban contexts and with high spatial variability. We will build on previous work from this field study by presenting i) a typology of urban soils according to anthropogenic content, ii) data for physical size fractionation to understand soil physical properties and texture, and iii) the carbon content of the size fractions to provide a proxy for understanding how labile or stable the carbon is. This will allow us to understand the impacts of soil sealing on the carbon content and build a picture of soil carbon stability across a range of urban situations.

This research will contribute to the much-needed understanding on how soil carbon behaves in urban areas, and the implications of this for carbon storage in both sealed and urban greenspace soils. 
An implicit physical water percolation model
Authors: van de Berg Willem Jan
Published: March 2020

The parametrization in numerical models of the behavior of water in snow is either oversimplified - the bucket method – or hugely complicated – the Richardson equation. The latter faithfully resembles the general behavior of water in snow, when a dual domain approach, representing slow matrix and fast preferential flow, is taken. However, this type of models are unsuitable for application in climate models due to their high computation costs.

Therefore, an implicit Richardson equation model is developed, which is able to run on time steps of several minutes, typical for climate models, and snow layer thickness down to a few centimeters. In order to reach to a differentiable governing equation, required for iterative implicit time stepping, with as few as possible discontinuities in the derivatives, favorable for convergence, modifications are made in the governing equations when the water content approaches the irreducible water content or water almost fills the available pore space. Here, we show the first results of this model, with a focus on the impact of parameterization choices on the modelled water flow, refreezing profile and melt water buffering capacity.
Model and state dependence of the atmospheric response to Arctic sea-ice loss
Authors: Walsh Amber , Screen James , Scaife Adam , Smith Doug , Eade Rosie
Published: March 2020

The climate response to Arctic sea-ice loss is highly uncertain. There exists considerable disagreement between observational and modelling studies, and between models, for reasons that remain poorly understood. To make progress, the Polar Amplification Model Intercomparison Project (PAMIP) was designed to provide coordinated experiments, with consistent sea-ice loss applied in multiple models. Results from the PAMIP are presented, focussing on the robustness of the atmospheric response to Arctic sea-ice loss across models and, within individual models, the dependence of the response on the mean state.

In the troposphere, the mid-latitude jet is either weakened and/or shifted towards the equator in all models, albeit with varying magnitudes. We hypothesise that the magnitude of the jet response is sensitive to the atmospheric model resolution. To test this, and to more broadly identify the aspects of the atmospheric response that are sensitive to model resolution, we compare like-for-like experiments with two versions of the HadGEM3 model at low (N96) and high (N216) horizontal resolution.

The stratospheric polar vortex response to Arctic sea-ice loss is not consistent between models, and appears to be influenced by both the size of the ensemble for each model and the phase of the Quasi-Biennial Oscillation (QBO). The possible modulating effect of the QBO is further explored using new simulations with background atmospheric states representing the easterly and westerly QBO phases.

A surprising early result from the PAMIP simulations were sizeable changes in the Southern Hemisphere in response to Arctic sea-ice loss and significant changes in the Northern Hemisphere in response to Antarctic sea-ice loss, even in atmosphere-only model experiments. The robustness of such apparent interhemispheric connections across models, ensemble sizes and mean states is investigated.

 

 

 
Morphology reveals deglaciation patterns of the Laurentide Ice Sheet in the Clyde Inlet fjord-cross-shelf trough system, eastern Baffin Island (Arctic Canada)
Authors: Couette Pierre-Olivier , Lajeunesse Patrick , Dorschel Boris , Gebhardt Catalina , Hebbeln Dierk , Brouard Etienne , Ghienne Jean-François
Published: March 2020

The maximal extent and subsequent deglaciation of the Laurentide Ice Sheet (LIS) across eastern Baffin Island during the last glacial cycle (MIS-2) has been widely debated during the last decades as different palaeo-glaciological models have been proposed. Spatial and temporal variability of ice sheets extension during Quaternary glaciations complicate the establishment of a reliable reconstruction of the ice dynamics in the area. Furthermore, the lack of geophysical data in most of the fjords, and seaward, makes it difficult to reconcile the proposed terrestrial and marine glacial margins. High-resolution swath-bathymetric data, collected between 2003 and 2017, display a diversity of glacial bedforms in the Clyde Inlet fjord-cross-shelf-trough system (Eastern Baffin Island, Arctic Canada). These bedforms reveal a potential position of the LIS margin during the Last Glacial Maximum (LGM) near the shelf break. Early deglaciation of the Clyde Trough was marked by an initial break up of the ice sheet. This rapid retreat of the ice margin was punctuated by episodic stabilizations forming GZWs. This retreat was followed by a readvance and subsequent slow retreat of the LIS, as indicated by the presence of recessional moraines. Long-term stabilizations within the trough possibly coincided with major climatic cooling episodes, such as the end of Heinrich event 1 (H1) and the Younger Dryas. However, these stabilizations appear to have been influenced by topography, as GZWs can be found at pinning points in the trough. Deglaciation of the fjord occurred during the early Holocene and was faster, probably due to increased water depths. The presence of multiple moraine systems however indicate that deglaciation of Clyde Inlet was marked by stages of ice margin stabilization.
Integrated Crop-Livestock-Forest Systems: Soil Carbon Sequestration and Organic Matter stabilization as detected by laser-based spectroscopies
Authors: Tadini Amanda Maria , Xavier Alfredo Augusto Pereira , Martin-Neto Ladislau , Milori Débora Marcondes Bastos Pereira , Bernardi Alberto Carlos de Campos
Published: March 2020

The Integrated Crop-Livestock-Forest Systems (CLF) have been able to capture and store the carbon (C) in the form of Soil Organic Matter (SOM), in different regions in Brazil, thereby contributing to mitigate agricultural greenhouse gases emission. This is an eligible practice in Low Carbon Emission Agriculture Plan in Brazil, and currently has around 15 million hectares under use, a very positive and important trend in soil land use in Brazil. SOM is considered a relevant indicator of soil quality due to its direct relationship with biological, chemical, and physical properties, allowing it to evaluate the impacts of agricultural management. Laser-based spectroscopies as Laser-Induced Fluorescence Spectroscopy (LIFS) and Laser-Induced Breakdown Spectroscopy (LIBS) have become promising tools in the evaluation of the SOM in agricultural soils. LIBS can measure soil C, and LIFS can infer about the chemical structure of SOM, mainly aromaticity. The standard protocol for measuring soil C changes involves soil sampling at the field and chemical sample preparation for laboratory analysis. Although this procedure produces precise results, it takes time, generates chemical residues, and the costs restrict its routine for large scale use in agricultural projects. Thus, there is a need to develop clean (green chemistry), rapid, precise, and cost-efficient methods for measuring soil C changes in the field. Also, information about the chemical structure of SOM usually is done through spectroscopic techniques, such as 13C NMR, EPR, and fluorescence of humic acid, which are not applied for large scale measurement and mapping. LIFS can be applied in whole soil and can be used to evaluate the aromaticity of SOM, and consequently, its chemical stability.  The objectives of this study were to evaluatethe soil C stock and SOM Stability of some Brazilian soils under different integrated systems, such as,Crop-Livestock-Forest (CLF), Crop-Livestock (CL) and Livestock-Forest(LF). The results showed the combination of soil carbon accumulation, and an increase of SOM aromaticity for CLF, which can be promising for sustainable intensification in agriculture.

Keywords: Sustainable Intensification; Soil Organic Matter; Carbon stock; Laser-Induced Fluorescence Spectroscopy; Integrated Crop-Livestock-Forest Systems
Solar cycle modulation of nighttime ozone near the mesopause as observed by MLS
Authors: Lee Jae N. , Wu Dong L.
Published: March 2020

Solar 11-year cycle variations of nighttime ozone near the secondary ozone maximum layer are analyzed with Aura Microwave Limb Sounder (MLS) observations since 2004 that covers complete solar cycle 24. Produced primarily from the recombination of molecular oxygen (O2) with single oxygen (O) transported from the lower thermosphere, the mesospheric nighttime ozone concentration is proportional to single oxygen density [O], of which the latter is modulated by UV solar cycle variations. MLS nighttime ozone and Solar Radiation and Climate Experiment (SORCE) Solar-Stellar Irradiance Comparison Experiment (SOLSTICE) measured UV show a positive correlation in-phase with the solar cycle. The nighttime ozone correlates strongly with temperature but not monotonously positive nor negative. The slope and sign of the correlation depend on location and season. They are positively correlated in general except for the boreal winter high latitudes.  Because the nighttime [O3] depends strongly on [O] in the upper mesosphere, it is expected the nighttime [O3] would follow the [O] distributions, producing similar diurnal, seasonal, and solar-cycle variations, as well as latitudinal distributions as observed in Carbon Monoxide (CO) in the upper mesosphere.
Review of city models and the applications on flood risk management
Authors: Chen Yiheng , Zhuo Lu , Han Dawei
Published: March 2020

Cities are the place where a large portion of the population lives. Traditional urban planning models usually based on separate functions of a city or region. A coherent city model is a newly developed tool to take the interaction between each section into consideration. The city model in this paper focuses on the water system infrastructure because flood risk is becoming an increasingly challenging issue with the rapid urbanization and extreme weather under climate change. The paper aims to give a timely review of the development of city models from various originates. Then, it introduces a number of popular modelling techniques that have been demonstrated useful or may be of potential usage for city modelling purpose, such as GIS, CIM, ABM, etc. The review of model techniques provides the readers with suggestions on how to choose the technique to deal with their own research question. After that, this paper also points out the possible future directions of city models with challenges requiring further research efforts.
The in-situ exploration of Jupiter's radiation belts
Authors: Roussos Elias ,   JUPITER_BELTS_TEAM
Published: March 2020

Jupiter has the most energetic and complex radiation belts in our solar system. Their hazardous environment is the reason why so many spacecraft avoid rather than investigate them, and explains how they have kept many of their secrets so well hidden, despite having been studied for decades. We believe that these secrets are worth unveiling, as Jupiter’s radiation belts and the vast magnetosphere that encloses them constitute an unprecedented physical laboratory, suitable for both interdisciplinary and novel scientific investigations: From studying fundamental high energy plasma physics processes which operate throughout the universe, such as adiabatic charged particle acceleration and nonlinear wave-particle interactions; to exploiting the astrobiological consequences of energetic particle radiation. The in-situ exploration of the uninviting environment of Jupiter’s radiation belts presents us with many challenges in mission design, science planning, instrumentation and technology development. We address these challenges by reviewing the different options that exist for direct and indirect observation of this unique system. We stress the need for new instruments, the value of synergistic Earth and Jupiter-based remote sensing and in-situ investigations, and the vital importance of multi-spacecraft, in-situ measurements. While simultaneous, multi-point in-situ observations have long become the standard for exploring electromagnetic interactions in the inner solar system, they have never taken place at Jupiter or any strongly magnetized planet besides Earth. We conclude that a dedicated multi-spacecraft mission to Jupiter’s radiation belts is an essential and obvious way forward. Besides guaranteeing many discoveries and outstanding progress in our understanding of planetary radiation belts, it offers a number of opportunities for interdisciplinary science investigations. For all these reasons, the exploration of Jupiter’s radiation belts deserves to be given a high priority in the future exploration of our solar system. A White Paper on this subject was submitted in response to ESA's Voyage 2050 call.
Tiltmeter Measurements at the Underground Rock Laboratory in Mont Terri
Authors: Rebscher Dorothee
Published: March 2020

Mont Terri rock laboratory, located in the Swiss Jurassic Mountains, was established with the focus on the investigation and analysys of the properties of argillaceous formations. The scope of Opalinus Clay as a safe, potential option for nuclear waste disposal was broaden, as the behaviour of claystone is of high interest also in the context of caprocks, and hence, for many dynamical processes in the subsurfaces. Extensive research has been performed already for more than 20 years by the partners of the Mont Terri Consortium. These close cooperations cover a broad range of scientific aspects using numerical modelling, laboratory studies, and last not least in-situ experiments. Here, included in the long-term monitoring programme, new investigations apply tiltmeters. Since April 2019, platform tiltmeters have been installed at various locations within the galleries and niches of Mont Terri. The biaxial instruments have resolutions of 1 nrad and 0.1 µrad, respectively (Applied Geomechanics and Lippmann Geophysikalische Messgeräte). The tilt measurements are embedded within various experiments contributing to specific, multiparametrical studies. However, the growing tilt network as a whole will also provide novel information of the rock laboratory. The different time-scales of interest include long-term observations of yearly and decadal variability. So far tilt signals were identified due to excavations during the recent enlargement of the laboratory, earthquake activity (Albania), and local effects. First results of these quasi-continuous recordings will be presented.
Projected future changes of meridional heat transport and heat balance of the Indian Ocean
Authors: Ma Jie , Feng Ming , Lan Jian , Hu Dunxin
Published: March 2020

An ocean downscaling model product, forced under the RCP8.5 future climate change scenario, has been used to understand the ocean heat balance of the Indian Ocean in a warming climate. Towards the end of the 21th century, the model simulates a significant reduction of Indonesian Throughflow (ITF) transport, which reduces the Pacific to Indian Ocean heat transport by 0.20 PW; whereas across S in the southern Indian Ocean (SIO), the southward heat transport is reduced by 0.28 PW, mainly contributed from the weakening western boundary current, the Agulhas Current (0.21 PW). The projected weakening of the Agulhas Current is to compensate for the reduction of the ITF transport, with additional contribution from the spin-down of the SIO subtropical gyre. Thus, being amplified by the ocean circulation changes in the SIO, the projected Indian Ocean warming trend is much faster than the direct air-sea heat flux input.
Testing sudden shifts in drylands through manipulative mesocosm experiments
Authors: Bautista Susana , Fornieles Francisco , Fuentes David , Urgeghe Anna M , Turrión Diana , Mayor Angeles G
Published: March 2020

A variety of theoretical and observational works indicate that drylands may experience sudden shifts from functional to degraded states in response to gradual increases in human and climatic pressures. However, there is little experimental testing of the factors and processes that control sudden shifts in drylands. Adopting a combination of mesocosms and manipulative experimental approach, we assessed the occurrence of sudden transitions towards degraded states in response to increasing pressure, and investigated the mechanisms underlying the observed dynamics. We mimicked a gradually increasing pressure of grazing and wood gathering by removing increasing amounts of vegetation on a series of experimental plots and mesocosms. We then monitored the impact of such gradient of pressure on runoff and sediment yield, vegetation dynamics, bare-soil connectivity and soil-surface condition over a 7-year period.  Overall, our results support that decreasing plant cover nonlinearly increases the loss of resources from the system and may trigger a change to a degraded state. Within the range from 40% to 30 % vegetation cover, a small change in the cover percentage resulted in a turning point in both the vegetation and the hydrological dynamics, driving the system to a new state that exhibited lower capacity for resource conservation all over the study period.
Origin of the Scotia Sea Magnetic Susceptibility Signal Across the MIS6-MIS5 Transition
Authors: Brachfeld Stefanie , Reilly Brendan , Tauxe Lisa , Lee Bridget , Weber Michael , Raymo Maureen , Williams Trevor , Bailey Ian , Garcia Marga , Guitard Michelle , Hemming Sidney , Martos Yasmina , OConnell Suzanne , Perez Lara F. , Ronge Thomas , Zheng Xufeng , Licht Kathy ,   Expedition 382 Scientists
Published: March 2020

Patterns of variability in Pleistocene magnetic susceptibility (k) from deep-sea sediment cores from the Scotia Sea show a striking similarity to patterns of dust flux recorded in the EPICA Dronning Maud Land (EDML) ice core.  Antarctic marine k records broadly reflect the interplay of lithogenic sediment provenance, biological productivity, sediment transport processes, and post-depositional diagenesis. Here we explore the origin of the Scotia Sea k record via a detailed rock magnetic study across the transition from MIS 6 to MIS 5. We analyzed bulk sediment and grain size separates in order to construct magnetic signatures of iceberg rafted debris (IBRD), sortable silt, and eolian input. The MIS 6-MIS 5 transition consists of three lithologies, a high k silty-clay-rich diatomaceous mud deposited during the glacial interval, an IBRD-rich but low k silty clay that marks the onset of deglaciation, and a low k diatomaceous ooze in which IBRD decreases forward through time. The high k glacial sediment is characterized by multi-domain hysteresis parameters, low χARM/χ values, S ratios near 1, and thermomagnetic curves indicative of low-Ti titanomagnetite. The absence of k peaks in the IBRD-rich silty-clay and IBRD rich diatomaceous ooze likely reflects the weakly magnetic lithogenic detritus supplied by Weddell Sea Embayment (WSE) ice streams, such as sandstone, quartzite, metasedimentary lithologies, phyllite and schist observed in lateral moraines adjacent to ice streams of the eastern WSE. The deglacial interval is characterized by elevated MR/MS, χARM/χ, and HIRM values, and decreased S-ratios in the bulk sediment, suggesting a greater proportion of high coercivity minerals such as hematite or goethite in the iron oxide assemblage. Preliminary data from grain size separates indicates that the clay mass fraction is > 0.5 in all three lithologies. Clay is also the dominant size fraction in the EDML ice core dust, with particle sizes generally < 5 μm. The Scotia Sea clay fraction k values are a factor 1.5 to 5 weaker than the silt fraction k values, and therefore are not the main carrier of the bulk k signal. The rock magnetic signatures of Scotia Sea sediment will be compared to those of terrestrial till and bedrock from the WSE, and to those of potential dust sources in South America to identify the sediment sources and environmental processes responsible for the k signal.
High Resolution Imaging of the South Hikurangi Subduction Zone, New Zealand, Using 2‐D Full‐Waveform Inversion
Authors: Djeffal Adnan , Pecher Ingo , Singh Satish , Kaipio Jari
Published: March 2020

Large quantities of fluids are predicted to be expelled from compacting sediments on subduction margins. Fluid expulsion is thought to be focussed, but its exact locations are usually constrained on very small scales and rarely can be resolved using velocity images obtained from traditional velocity analysis and ray-based tomography because of their resolution and accuracy limitation. However, with recent advancement in computing power, the full waveform inversion (FWI) is a powerful alternative to those traditional approaches as it uses phase and amplitude information contained in seismic data to yield a high-resolution velocity model of the subsurface.

Here, we applied elastic FWI along an 85 Km long 2D multichannel seismic profile on the southern Hikurangi margin, New Zealand. Our processing sequence includes: (1) downward continuation, (2) 2D traveltime tomography, and (3) full waveform inversion of wide-angle seismic data. We will present the final high-resolution velocity model and our interpretation of the fluid flow regimes associated with both the deforming overriding plate and the subducting plate.
Studies of seismic velocities in subduction zones from continuous OBS data
Authors: Wang Weiwei , Savage Martha , Yates Alec , Hung Shu-Huei , Luo Yinhe , Stern Tim , Lin Pei-Ying Patty , Yang Hsin-Ying , Kuo Ban-Yuan , Fry Bill , Webb Spahr
Published: March 2020

In recent years, Ocean Bottom Seismometers (OBSs) have become widely used to expand the coverage of seismic networks onto the ocean. This study takes advantage of offshore observations at the northern end of the Hikurangi margin and southwestern Okinawa Trough to study the tectonics in both regions.

In the Hikurangi subduction zone, slow slip events (SSEs) have been observed, which are caused by the subduction of the Pacific Plate under New Zealand. The behaviour of SSEs and how they influence the physical properties of Earth materials are open to question. From 2014 to 2015, 15 OBSs were deployed offshore Gisborne, New Zealand on the Hikurangi margin. Ambient noise data from the OBSs are used to study velocity changes related to SSEs. Single station cross-component correlations and auto-correlations are computed, from which coda waves are used to monitor the velocity changes before, during and after the SSEs in 2014 and 2015 to analyse the slow earthquake behaviour and its relation to stress changes. Different rotation on horizontal components is tested by rotating horizontal components to N-E direction and parallel-perpendicular to the coastline. The dv/v computed by different components or rotation show different changes. The averaged dv/v displays a 0.1% velocity decrease during the SSE in October 2014.

The southwestern Okinawa Trough tapers towards Taiwan. How the back-arc crust accommodates the narrowing processing remains to be understood. At various times between 2010 and 2017, 22 OBSs on a small scale (~0.2°×0.3°) were deployed in Southwestern Okinawa Trough offshore northeast Taiwan. Ambient noise recorded on vertical velocity and pressure sensors is used to retrieve Scholte waves for studying shear wave velocity structure. Phase velocities are forward-modeled according to a model proposed by Kuo et al. 2015 and shear strength and density results from ODP1202. Phase velocity dispersion curves are measured from cross-correlations and unwrapped according to the modeled phase velocities. The fundamental mode phase velocities averaged from different station pairs are 0.62 km/s at 3 s period and 1.56 km/s at 6.5 s period. A 3D inversion will be conducted for a shear wave velocity structure from the basin center to the edge.
Enabling Science at Scale
Authors: de La Beaujardiere Jeff
Published: March 2020

The geosciences are facing a Big Data problem, particularly in the areas of data Volume (huge observational datasets and numerical model outputs), Variety (large numbers of disparate datasets from multiple sources with inconsistent standards), and Velocity (need for rapid processing of continuous data streams). These challenges make it difficult to perform scientific research and to make decisions about serious environmental issues facing our planet. We need to enable science at the scale of our large, disparate, and continuous data.

One part of the solution relates to infrastructure, such as by making large datasets available in a shared environment co-located with computational resources so that we can bring the analysis code to the data instead of copying data. The other part relies on improvements in metadata, data models, semantics, and collaboration. Individual datasets must have comprehensive, accurate, and machine-readable metadata to enable assessment of their relevance to a specific problem. Multiple datasets must be mapped into an overarching data model rooted in the geographical and temporal attributes to enable us to seamlessly find and access data for the appropriate location and time. Semantic mapping is necessary to enable data from different disciplines to be brought to bear on the same problem. Progress in all these areas will require collaboration on technical methods, interoperability standards, and analysis software that bridges information communities -- collaboration driven by a willingness to make data usable by those outside of the original scientific discipline.