bluuebunny/crossref_metadata_2025 huggingface dataset:
Flood Risk Characterization of Highly Flood-prone Data Scarce Region under Changing Climate
Authors: Gusain Aditya , Sudharsan Naveen , Karmakar Subhankar , Ghosh Subimal
Published: March 2020

It is evident that changes in climate alter the incidence of hydro-climatic extreme events, specifically floods, which are likely to cause irreparable socio-economic and ecological damages. With a 7,516 km coastline that is prone to climate-mediated disturbances and cyclones, the eastern coast of the Indian subcontinent is comparatively more vulnerable to the changing climate and land use with higher incidences of extensive flooding. Therefore, the policy-makers and decision-making authorities are dependent on the scientific community to provide reliable estimates of hydro-meteorological variables for simulating extreme events under the impact of climate change. However, a comprehensive flood risk framework at a finer administrative level is not yet available under the Indian scenario that assesses the changing dynamics and complexities of different components of climatic risk (hazard, vulnerability, and exposure). The present study attempts to demonstrate a proposed framework of flood risk assessment for a highly flood-prone deltaic region of Mahanadi River Basin, India, under climate change scenarios for near-future (the 2040s) at present-day vulnerability and exposure status. It was noted that changes in future flood risk are highly influenced by the vulnerability and exposure status of the region. Lower vulnerability and exposure in coastal sub-districts reduces the overall risk even if a higher flood hazard is observed. Under both future scenarios, RCP 4.5 and 8.5, the number of villages under high hazard zones with greater flood magnitude has increased. Therefore, it thrusts upon the need to adopt stringent actions for devising better adaptation strategies and sustainable planning which can aid in lowering the vulnerability of the region to future floods.
The SMILE mission: A novel way to explore solar-terrestrial interactions
Authors: Branduardi-Raymont Graziella , Wang Chi , Escoubet C. Philippe , Sembay Steve , Donovan Eric , Dai Lei , Li Lei , Li Jing , Agnolon David , Raab Walfried , Rae Jonathan , Read Andy , Spanswick Emma L. , Carter Jenny A. , Connor Hyunju , Sun Tianran , Samsonov Andrey , Sibeck David G.
Published: March 2020

The coupling between the solar wind and the Earth's magnetosphere-ionosphere system, and the geospace dynamics that result, comprise some of the key questions in space plasma physics. In situ measurements by a fleet of solar wind and magnetospheric missions, current and planned, can provide the most detailed observations of the Sun-Earth connections. However, we are still unable to quantify the global effects of the drivers of such connections, and to monitor their evolution with time. This information is the key missing link for developing a comprehensive understanding of how the Sun gives rise to and controls the Earth's plasma environment and space weather.

SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) is a novel self-standing mission dedicated to observing the solar wind - magnetosphere coupling via simultaneous X-ray imaging of the magnetosheath and polar cusps (large spatial scales at the magnetopause), UV imaging of global auroral distributions (mesoscale structures in the ionosphere) and in situ solar wind/magnetosheath plasma and magnetic field measurements. X-ray imaging of the magnetosheath and cusps is made possible by the X-ray emission produced in the process of solar wind charge exchange, first observed at comets, and subsequently found to occur in the vicinity of the Earth's magnetosphere. One of the science aims of SMILE is to track the substorm cycle, via X-ray imaging on the dayside and by following its consequences on the nightside with UV imaging. 

SMILE is a collaborative mission between ESA and the Chinese Academy of Sciences (CAS) that was selected in November 2015, adopted into ESA’s Cosmic Vision Programme in March 2019, and is due for launch at the end of 2023. The science that SMILE will deliver, as well as the ongoing technical developments and scientific preparations, and the current status of the mission, will be presented.

 
Introducing plausible mega-droughts in hydropower scheduling at the power grid level
Authors: Olivares Marcelo , Pereira Eduardo , Abarzua Fernanda , Gomez Matias , Orellana Diana
Published: March 2020

Hydropower operations are commonly prescribed as part of a grid-wide coordination process by an Independent System Operator (ISO). The scheduling problem is usually divided into two coupled problems: short- and medium-term scheduling. The medium term problem, usually within a planning horizon of a few years, takes into account uncertain inflows to every hydropower plant in the grid. This uncertainty is often represented by a scenario tree constructed from historical records. The result of this stochastic optimization problem is a set of Future Value Functions (FVF) of water in the reservoirs. These functions represent the carryover storage value, as avoided future thermal costs, for each week within the planning horizon. These FVFs are then used as a boundary condition for short-term scheduling within each week.

Chile has suffered a 10-year severe drought since 2010. Moreover, climate projections for Chile suggest an intensification of droughts in the future, in terms of both frequency and magnitude. From the water-energy nexus perspective, this phenomenon would rise energy costs and prices, and at the same time, push the electric coordinator to feed the system with less clean sources of electricity.

This work proposes and tests alternative ways to introduce plausible mega-droughts in Chile as part of the power scheduling process. We develop series representing plausible future conditions of drought and severe drought, preserving the time and spatial correlation structure of inflows. These scenarios are then used, along with historical information, to develop FVFs that take into account those severe drought scenarios. The method is tested in Chile’s main grid, represented by 624 power plants, 103 inflow points, 13 reservoirs, and 58 demand nodes.

The FVFs obtained from each alternative approach are then simulated under a wide range of futures. Results show that the introducing very severe droughts is not the best course of action, as the corresponding FVFs perform very poorly under moderately dry futures. In contrast, introducing scenarios with a moderate dry bias performs better over a wide range of future conditions, except for extremely severe droughts.   
Solar induced earthquakes – review and new results
Authors: Pulinets Sergey , Khachikyan Galina
Published: March 2020

A lot of information has been accumulated recently demonstrating impacts of solar activity on the Earth’s seismicity. We observe the transition from correlation-driven papers to the more physical based works. The effects of solar influence could be separated by agents of energy transfer which could be electromagnetic emission of the Sun, particle fluxes of solar wind, solar proton events, modification of radiation belts and indirect impacts through the intermediate agent, such as atmosphere disturbances and modification of atmosphere circulation as effect of solar activity. Effects of the galactic cosmic rays should be taken into account including the Forbush decreases, which are result of geomagnetic storms. MHD electromagnetic sounding stimulating the earthquake activity could be considered as a physical model of the geomagnetic storms effect on the seismic activity.

The most intriguing effects discovered recently is the inducing the strong M>7 earthquakes by the precipitation from additional radiation belt at L-shell 1.5-1.8 formed after the strong geomagnetic storm. Precipitation of relativistic particles from this shell induces the strong earthquakes with delay nearly 2 months.

One very importing agent of geosphere coupling including the energy transfer int the lithosphere is the Global Electric Circuite.

It is difficult to explain the observed phenomena by simple transformation of solar energy into mechanical deformation, it seems that more plausible explanation is the pumping of energy into the Earth’s crust volume being in a metastable state.

This work was supported by the Ministry of Education and Science of the Russian Federation in accordance with Subsidy Agreement No. 05.585.21.0008. The unique identifier is RFMEFI58519X0008
The use of multidimensional Langevin processes for stochastic uncertainty quantification in the NOAA Unified Forecast System (UFS)
Authors: Bao Jian-Wen , Michelson Sara , Bengtsson Lisa , Pegion Philip , Whitaker Jeffrey , Penland Cécile
Published: March 2020

Modern numerical weather prediction (NWP) model forecasts for various applications require not only high-quality deterministic forecasts, but also information about forecast uncertainty.  An ensemble forecast is commonly used to provide an estimation of forecast uncertainty.  Since a great deal of the forecast uncertainty comes from dynamical processes not resolved or explicitly represented by NWP models, there is a need to correctly quantify and simulate NWP model uncertainty for an ensemble forecast to be useful and reliable.

We present an overview of a theoretical framework for simulating the uncertainty in unresolved physics in the NOAA Unified Forecast System (UFS).  This framework is derived from the connection in mathematical physics between the Mori-Zwanzig formalism and multidimensional Langevin processes.  It follows the correspondence principle, a philosophical guideline for new theory development, such that it can be shown that the previously implemented stochastic uncertainty quantification schemes in the UFS are particular cases of this framework.  We will show an example of how we have used this framework to develop a new process-level stochastic uncertainty quantification scheme in the UFS.  We will also present a preliminary performance comparison of these previously-implemented schemes with the newly-developed process-level scheme in the UFS ensemble predictions on short, medium and sub-seasonal time scales.
Flexible open-source software for modelling wind disturbance and damage to trees and forests
Authors: Locatelli Tom , Hale Sophie , Nicoll Bruce , Gardiner Barry
Published: March 2020

Wind disturbance to forests extends across spatial and temporal scales and encompasses direct and indirect wind effects on the dynamics of forest ecosystems. It is detrimental to the provision of ecosystem services and reduces forest resistance and resilience to future natural disturbances. Historically, in the ecological and land-use scientific communities, forecasting the extent and probability of wind disturbance to forests has represented a serious challenge, with most studies electing to adopt qualitative or statistical approaches. The low degree of portability of statistical assessments of vulnerability to wind has limited their applicability and use, but it is recognised that they have a role in building hypotheses of the processes involved in wind damage that can be subsequently tested under experimental conditions. Results from tree stability experiments have contributed, in the last two decades, to the development of a mechanistic model of wind damage - ForestGALES. This is a process-based wind risk model that was originally created to inform the management of commercial forest plantations in the UK. Built on principles of forest science, physics, and ecology, ForestGALES requires a simple set of inputs and it has now been expanded to cover more than 20 common conifer species from across three continents, and multiple broadleaved species (e.g. Oak, Beech, Birch, and Eucalypts). Two methods of assessing vulnerability to wind damage are available in ForestGALES, one designed for application at stand level, and a novel approach that estimates vulnerability to wind at the individual tree within a stand – the latter allowing for use in complex forest stands, and for the effect of competition between trees in a stand. Until recently, ForestGALES was only available as desktop software and as an online tool as part of forest decision support systems (only for selected countries and species). These formats can be limiting for research and academic projects that aim to model and understanding wind disturbance dynamics across diverse landscapes, and that require a bespoke approach with a high degree of flexibility. To accommodate these broader requirements, ForestGALES has recently been redeveloped and released as a FOSS R package (“fgr”) that is fully customisable and easily integrated in R and modelling workflows and FOSS GIS frameworks. With this poster we present two exemplar studies of assessing wind damage risk to forested landscapes, one for each ForestGALES method (stand- and individual trees level), to showcase the capabilities and flexibility of the model in working with e.g. climate projection data, with other process-based models (e.g. 3PG) within an R modelling framework, and with LiDAR data, at the individual tree level.
Linking thermomechanical models with geodetic observations to evaluate the 2018 eruption of Sierra Negra Volcano, Galápagos
Authors: Gregg Patricia , Zhan Yan , Amelung Falk , Albright Jack , Geist Dennis , Mothes Patricia , Yunjun Zhang , Koric Seid
Published: March 2020

Ensemble based data assimilation approaches, such as the Ensemble Kalman Filter (EnKF), have been widely and successfully implemented to combine observations with dynamic models to investigate the evolution of a system’s state. Such inversions are powerful tools for providing forecasts as well as “hindcasting” events such as volcanic eruptions to investigate source parameters and triggering mechanisms. In this study, a high performance computing (HPC) adaptation of the EnKF is used to assimilate ground deformation observations from interferometric synthetic-aperture radar (InSAR) into high-fidelity, multiphysics finite element models to evaluate the prolonged unrest and June 26, 2018 eruption of Sierra Negra volcano, Galápagos. The stability of the Sierra Negra magma system is evaluated at each time step by estimating variations in reservoir overpressure, Mohr-Coulomb failure in the host rock, and tensile stress and failure along the reservoir boundary. The deformation of Sierra Negra is tracked over a decade, during which almost 5 meters of surface uplift has been recorded. The EnKF reveals that the evolution of the stress state in the host rock surrounding the Sierra Negra magma reservoir likely controlled the timing of the eruption. While increases in magma reservoir overpressure remained modest (< 10 MPa) throughout the data assimilation time period, significant Mohr-Coulomb failure is indicated in the lead up to the eruption coincident with increased seismicity along both trapdoor faults within Sierra Negra’s caldera and along the caldera’s ring faults. During the final stages of pre-eruptive unrest, the EnKF models indicate limited tensile failure, with no tensile failure along the northern portion of the magma system where the eruption commenced. Most strikingly, model calculations of significant through-going Mohr-Coulomb failure correspond in space and time with a Mw 5.4 earthquake recorded in the hours preceding the 2018 eruption. Subsequent stress modeling implicates the Mw 5.4 earthquake along the southern intra-caldera trapdoor fault as the potential catalyst for tensile failure and dike initiation along the reservoir to the north. In conclusion, the volcano EnKF approach successfully tracked the evolving stability of Sierra Negra, indicating great potential for future forecasting efforts.
Does shrubs growth in the high-Arctic lead to permafrost warming?
Authors: Domine Florent , Lackner Georg , Belke-Brea Maria , Sarrrazin Denis , Nadeau Daniel
Published: March 2020

With climate warming shrubs can grow on high-Arctic tundra. This impacts many terms of the energy budget, resulting in a modification of the permafrost thermal regime. The summer surface albedo is decreased. The winter surface albedo is decreased because shrubs protrude above the snow. Winter conductive fluxes through the snow are reduced because shrubs trap snow, increasing snow depth. Shrubs also favor both snow melt in fall and spring and depth hoar formation in fall and winter, and both these factors affect snow thermal conductivity. Soil thermal properties may also be affected because of increased moisture.  We have measured many terms of the energy budget at Bylot Island, 73°N, Canada, at a herb tundra site and in a nearby large willow shrub patch. Monitored variables include radiation, snow and soil thermal conductivity and standard atmospheric variables. We observe that soil temperature at 15 cm depth is 1.5°C warmer under shrubs on a yearly average. The energetics of both sites are simulated using SurfexV8 including the detailed snow model Crocus. Combining observations and simulations indicates that the increased soil moisture under shrubs, by delaying  freezing by one month in fall, is an important factor in winter soil warming. Summer temperature is also markedly warmer under shrubs because of lower albedo and because the shrub understory is less insulating than on herb, which facilitates warming. These results show that investigating shrub impact using manipulations such as shrub removal is questionable because it does not restore pre-shrub understory and moisture.
Stochastic comparison of climate model outputs to observed precipitation fields
Authors: Gerotoliou Styliani , Iliopoulou Theano , Dimitriadis Panayiotis , Koutsoyiannis Demetris
Published: March 2020

We compare the stochastic behaviour of precipitation outputs of climate models for the 20th century to the historical data (stations and reanalysis fields) at several temporal and spatial scales. In particular we examine the marginal distributions and the dependence structure with emphasis on the Hurst-Kolmogorov behaviour. The comparison aims to contribute to the quantification of reliability and predictive uncertainty of precipitation climate model outputs over different scales in a framework of assessing their relevance for engineering planning and design.

 

(Acknowledgement: This research is conducted within the frame of the course "Stochastic Methods" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students in the Assembly.)
Degraded peatlands of South East Asia : a source of Trace Metal to surface waters
Authors: Gandois Laure , Hoyt Alison M. , Mounier Stéphane , Le Roux Gaël , Harvey Charles F. , Claustres Adrien , Nuriman Mohammed , Anshari Gusti
Published: March 2020

Worldwide, peatlands are important sources of dissolved organic matter (DOM) and trace metals (TM) to surface waters and these fluxes may increase with peatland degradation. In Southeast Asia, tropical peatlands are being rapidly deforested and drained. The black rivers draining these peatland areas have high concentrations of DOM. However, the fate of this fluvial carbon export is uncertain, and its role as a trace metal carrier has never been investigated. This work aims to address these gaps in our understanding of tropical peatland DOM and associated elements in the context of degraded tropical peatlands of Indonesian Borneo. We quantified dissolved organic carbon and trace metals concentrations in the dissolved, fine colloidal and coarse colloidal fractions and determined the characteristics (optical and isotopic) of the peatland-derived DOM as it drains from peatland canals, flows along black river and eventually mixes with the Kapuas Kecil River before meeting the ocean near the city of Pontianak in West Kalimantan, Indonesia. Black rivers draining degraded peatlands show significantly higher concentrations of Al, Fe, Pb, As, Ni, and Cd, compared the white river. A strong association is observed between DOM, Fe, As, Cd and Zn in the dissolved and fine colloid fraction, while Al is associated to Pb and Ni and present in a higher proportion in the coarse colloidal fraction. We additionally measured the isotopic composition of lead released from degraded tropical peatlands for the first time and show that Pb originates from anthropogenic atmospheric deposition. Degraded tropical peatlands are important sources of DOM and trace metals to rivers and a secondary source of atmospherically deposited contaminants.
Collaboration project around United Nations Sustainable Development Goals with focus on climate change and human rights
Authors: Bredberg Camilla , Bergqvist Anna
Published: March 2020

Climate change is one of the most important global issues affecting the entire population on the earth, particularly young people. Since climate change is already threating us all, it is of utmost importance to raise this issue in a wide range of community policies, including school programs. In line with this reasoning, teacher at our school have together started a collaborative project in different subject as Natural Science, Swedish, Economics, Human Rights and Social Science focused on United Nations Sustainable Development Goals. The primary objective with this collaborative project is to work with United Nations sustainaable Development Goals since it is applicable to the school subjects in many different aspects, including Economic, Social science and Science. An important objective of this project is to provide students with educational and practical training in how to make scientific inquiries and write a scientific report. During this school year, participating students will attend lectures and exhibitions concerning United Nations’ Sustanable Development Goals. In April 2020 the students will present their reports in a conference at the department of Geological Sciences at Stockholm University.
Derivation of climate-indices and establishment of hazard-development-corridors along the ÖBB rail network
Authors: Wally Christian , Lehner Sebastian , Matulla Christoph , Enigl Katharina , Müller Helene , Rauch Hans Peter , Fian Tabea , Hauger Georg , Rachoy Christian , Salinger Florian
Published: March 2020

The Austrian Federal Railways (ÖBB) are operating about 4800 kilometers of railway track in all regions of Austria. Most parts of this infrastructure are exposed to various natural hazards like landslides, debris flows, rockfalls, floodings and avalanches but also extreme weather events like strong winds or extreme heat can disrupt railway traffic. The frequency of their occurrence is changing due to recent climate change.

We use over 2000 events from 1990 to 2018 and a principal component approach to create an event space which lets us combine events and meteorological data on a fine spatial grid. This is necessary to detect characteristic climate-indices (CIs) in temporal series of meteorological parameters, like temperature or precipitation, that have negative effects on railway operation or trigger natural hazards that do so. The results are evaluated using various multivariate statistic methods to quantify the quality of the found CIs.

After these steps we can estimate the frequency of CI occurrence in near (2036-2065) and remote future (2071-2100) by analyzing ensembles of downscaled GCM projections for different climate scenarios. The result are hazard-development-corridors that are a relative measure for the number of predicted hazard events during the two periods of time along the considered railway tracks.
A 500-year record of paleoclimate and paleoenvironment from the Lacandon Forest, southern Mexico
Authors: Rubio Sandoval Karla Zurisadai , Correa-Metrio Alexander , Franco-Gaviria Juan Felipe , Schwalb Antje , Hoelzmann Philipp , Brenner Mark , Blaauw Maarten , Kenney William , Curtis Jason , Pérez Liseth
Published: March 2020

Tropical karst Lakes Metzabok (550 masl, surface area = ~77 ha, zmax = 25 m) and Nahá (832 masl, surface area = ~57 ha, zmax = 36 m) are located in the Lacandon Forest, in the state of Chiapas, southern Mexico. The region is characterized by high aquatic and terrestrial biodiversity. We generated high-resolution paleoclimate and paleoenvironmental records that span the last ~500 years, using invertebrate remains (ostracodes and gastropods) and geochemical variables (elemental and mineralogical contents) in sediment cores from the two water bodies. We collected a short sediment core from each lake (Metzabok = 46 cm, Nahá = 60 cm) and analyses were carried out at 1-cm intervals. Uppermost sediments in the cores were dated using 210Pb and 137Cs, and deeper deposits were dated by 14C. Ostracodes and snails were identified to species level and their abundances were quantified. Concentrations of Ti and Fe were determined by portable XRF. The geochemical record reveals information about past climate variability, human-mediated erosion and transport of terrigenous elements. Changes in ostracode and gastropod assemblages mainly reflect past lake level fluctuations and changes in water conductivity. The dominant ostracode species was Cytheridella ilosvayi and the most common gastropod is Aroapyrgus sp., indicative of water depths ≤40 m and low water conductivity, respectively. Analysis of the ecological distances between samples suggests that Lake Metzabok is unstable, with frequent ecological changes equal to or greater than 50% of the community. These changes may have resulted from dramatic environmental differences associated with hydrological dynamics during dry and rainy seasons. The Nahá record presents two environmental conditions, i.e. periods of high stability and periods of change, when the system was in transition from a dry period to a wetter one, or vice versa. Despite differences between the two lakes with respect to elevation, size, depth, and seasonal dynamics, both records contain evidence of droughts ca. 300 and 200 yr BP, during the Little Ice Age. Whereas both records show a long-term tendency towards higher moisture conditions, the high-resolution of our study enabled us to detect fluctuations between dry and wet periods over the last 500 years that previous studies failed to recognize.
Structural features extracted from voxelised full-waveform LiDAR using the open source software DASOS for detecting dead standing trees
Authors: Miltiadou Milto , Prodromou Maria , Agapiou Athos , Hadjimitsis Diofantos G.
Published: March 2020

DASOS is an open source software developed by the authors of this abstract to support the usage of full-waveform (FW) LiDAR data. Traditionally LiDAR record only a few peak point returns, while FW LiDAR systems digitizes the entire backscattered signal returned to the instrument into discrete waveforms. Each waveform consists of a set of waveform samples equally spaced. Extraction of peak points from waveforms reduces data and they can be embedded into existing workflows. Nevertheless, this approach discretizes the data. In recent studies, voxelization of FW LiDAR data has been increased. The open source software DASOS uses voxelization for the interpretation the FW LiDAR data and has four main functionalities: (1) extraction of 2D metrics, e.g. height, density, (2) reconstruction of 3D polygonal meshes from the data (3) alignment with hyperspectral imagery for generating aligned metrics with the FW LiDAR data and colored polygonal meshes, (4) extraction of local features using 3D windows, e.g. standard deviation of heights within the 3D window.

Here, we do not only present the functionalities of DASOS but also how the extraction of complex structural features from local areas, 3D windows, could be used for improving forest inventories. In Southern Australia, dead trees plays a substantial role in managing biodiversity since they are more likely to contain hollows and consequently shelter native, protected species. The study area is a native River Red Gum (Eucalyptus camaldulensis) forest. Eucalypt trees are difficult to delineate due to their irregular shapes and multiple trunk split. Using field data, positive (dead standing trees) and negative (live trees) samples were defined and for each sample multiple features were extracted using 3D windows from DASOS. With 3D object detection, it was shown that it is possible to detect them without tree delineation. The studies was further improved with the introduction of multi-scale 3D windows for categorizing trees according to their height and doing a three pass detection, one for each size category. By cross validating the results, it was shown that the multi-scale 3D-window approach further improved detection of dead standing Eucalypt trees. The extraction of structural features using DASOS and the methodology implemented could be applied to further forest related applications.

The project ‘FOREST’ (OPPORTUNITY/0916/0005) is co-financed by the European Regional Development Fund and the Republic of Cyprus through the Research Innovation Foundation.
Interdisciplinary collaboration in the development of IPCC report glossaries
Authors: Matthews Robin , van Diemen Renee , Weyer Nora Marie , Baidya Jesbin
Published: March 2020

The Intergovernmental Panel on Climate Change (IPCC) produces assessment reports on climate change, spanning physical climate science, climate impacts and adaptation, and mitigation. These reports draw upon scientific, technical and socio-economic information and are produced by interdisciplinary and international author teams. The reports, including their glossaries, are used by diverse audiences across the natural and social sciences, policy and practice, and education. IPCC report glossaries are an invaluable resource in their own right, covering the domains of each report and providing rigorous definitions for terms that are oft-used in public discourse.

The IPCC is currently in its Sixth Assessment Cycle (AR6), for which it has already released three Special Reports, and is currently preparing three Working Group (WG) Reports and a Synthesis Report to be released in 2021/22. Since each report and report chapter is written by a different author team, ensuring consistency in approach and conclusions across and within each report represents a key challenge. An important contribution towards achieving consistency is the development of single definitions for terms to be used across several reports. To facilitate the development of such definitions, the IPCC Secretariat and Technical Support Units have created custom software for internal author use, termed the Collaborative Online Glossary System (COGS). In addition, a public portal for IPCC glossaries (https://apps.ipcc.ch/glossary/) has been developed, where AR5 and approved AR6 report glossaries are hosted and can be readily searched. Here we discuss these tools within the context of interdisciplinary collaboration in climate change assessment. We also highlight the benefits of having consistent definitions when working more broadly at the water-energy-land nexus.
ERDA: External Version-Controlled Research Data
Authors: Rath Willi , Schirnick Carsten , Faber Claas
Published: March 2020

This presentation will detail the design, implementation, and operation of ERDA, which is a collection of external version-controlled research datasets, of multiple synchronized deployments of the data, of a growing set of minimal examples using the datasets from various deployments, of stand-alone tools to create, maintain, and deploy new datasets, and of documentation targeting different audiences (users, maintainers, developers).

ERDA was designed with the following principles in mind: Provide clear data provenance and ensure long-term availability, minimize effort for adding data and make all contents available to all users immediately, ensure unambiguous referencing and develop transparent versioning conventions, embrace mobility of scientists and target independence from the infrastructure of specific institutions.

The talk will show how the data management is done with Git-LFS, demonstrate how data repositories are rendered from human-readable data, and give an overview of the versioning scheme that is applied.
Ephemeral Gully Erosion Advancements within the AnnAGNPS Watershed Simulation Model
Authors: Bingner Ronald , Wells Robert , Momm Henrique
Published: March 2020

Concentrated runoff increases erosion and moves fine sediment and associated agrichemicals from upland areas to stream channels. Ephemeral gully erosion on croplands in the U.S. may contribute more of the sediment delivered to the edge of the field then from sheet and rill erosion. Typically, conservation practices developed for sheet and rill erosion are also expected to treat ephemeral gully erosion, but science and technology are needed to account for the separate benefits and effects of practices on each of the various sediment sources.

Watershed modeling technology has been widely developed to aid in evaluating conservation practices implemented as part of a management plan, but typically lacks the capability to identify how a source, such as sheet and rill erosion, ephemeral gully erosion, or channel erosion, is specifically controlled by a practice or integrated practices. The U.S. Department of Agriculture’s Annualized Agricultural Non-Point Source pollutant loading model, AnnAGNPS, has been developed to determine the effects of conservation management plans on erosion and provide sediment tracking from all sources within the watershed, including sheet and rill, ephemeral gully, and channel erosion. 

This study describes the ephemeral gully erosion capabilities within the AnnAGNPS model and discusses research needs to further improve these components for integrated conservation management planning.  Conservation management planning by agencies within the U.S. and by international organizations requires a systematic approach when determining the extent of ephemeral gully erosion impacts on a field, watershed, or national basis, and/or to predict recurring or new locations of ephemeral gullies prior to their development.  This technology provides the capability to separate the impact of ephemeral gullies on erosion from other sources and then evaluate the impact of targeted practices to control erosion at the source and subsequent downstream resources.
Towards a 3-D model for large-scale glacier simulations
Authors: Zekollari Harry , Goelzer Heiko , Pattyn Frank , Wouters Bert , Lhermitte Stef
Published: March 2020

Glaciers outside the two major ice sheets are key contributors to sea level rise, act as important sources of freshwater, and have great touristic value. To simulate the temporal evolution of these ice masses at regional- to global scale, simplified models are typically used that rely on volume scaling approximations or parameterizations based on observed glacier changes. These approaches rely on minimal data and are fast, but they do not account for mass redistribution through ice flow. More recently, efforts have been undertaken to represent ice dynamical processes in flowline models that can be applied at large spatial scales. These flowline approaches represent the mass transfer within a glacier in a more realistic way, but fail at reproducing the evolution of large glaciers, which are typically not confined by the local topography and do not have a pronounced elongated shape as represented in flowline models.

Here we present our first efforts to develop a 3D coupled surface mass balance – ice flow model that can be used to model the temporal evolution of an ensemble of glaciers. The main goal of such a model is to be able to simulate the temporal evolution of glaciers with distinct shapes and situated in various climatic regimes in an automated way. By relying on a 3D model architecture we aim to better represent processes crucial for glacier evolution, such as glacier calving and convergent flow from several tributaries. Here, we will present first tests with a prototype version of the model by reproducing steady state geometries of selected glaciers, and by simulating the evolution of these ice bodies under idealised forcing scenarios.
Modeling relevant factors and covariates of carbon stock changes in peatlands using a hierarchical linear mixed modeling approach
Authors: Walz Kilian , Byrne Kenneth A , Wilson David , Renou-Wilson Florence
Published: March 2020

While peatlands constitute the largest soil carbon stock in Ireland with 75% of soil carbon stored in an area covering an estimated 20% of the land surface, carbon stocks of peatlands are affected by past and present disturbances related to various land uses. Afforestation, grazing and peat extraction for energy and horticultural use often are major drivers of peatland soil degradation. A comparative assessment of the impact of land disturbance on peatland soil carbon stocks on a national scale has been lacking so far. Current research, funded by the Irish Environmental Protection Agency (EPA), addresses this issue with the goal to fill various gaps related to mapping and modeling changes of soil carbon stock in Irish peatlands. Data from the first nationwide peatland survey forms the basis for this study, in which the influence of different factors and covariates on soil carbon distribution in peatlands is examined. After data exploratory analysis, a mixed linear modeling approach is tested for its suitability to explain peatland soil carbon distribution within the Republic of Ireland. Parameters are identified which are responsible for changes across the country. In addition, model performance to map peat soil carbon stock within a three-dimensional space is evaluated.
You can't be what you can't see - Increasing the visibility of female scientists
Authors: Ebner Ronja , Baxter Allix , Cox Jana , Dunn Frances , Hagemans Kimberley , Roelofs Lonneke
Published: March 2020

The Young Women of Geosciences (YWoG) go by the maxim “You can’t be what you can’t see”. We are a group of early stage researchers at Utrecht University striving to make universities more diverse and inclusive. The group was honoured with the university’s Diversity & Inclusion Award 2020 for its goals and activities. 

Although the Netherlands rank high in equality [Gender-Equality-Index of the EU, 2019] and the gender balance among students is close to 50:50, there is still a huge discrepancy when it comes to the male-to-female ratio of employed researchers and their wages [Monitor Vrouwelijke Hoogleraren 2019]. While the various causes for the gender gap are highly debated, we feel strongly that a lack of role-models is one of them.  

Hence, our goals are to increase the visibility of female scientists, connect women to improve the exchange of experiences and to raise awareness for problems caused by a non-diverse and non-inclusive environment. Our regular workshops and soft research on gender in the classroom are therefore aimed at understanding and improving the dynamics within mixed groups. For the same reason we keep our events open to people of all genders. 

In order to achieve our goals, we focus on showcasing role-models by organising “meet & greets”, where young scientists like PhDs and postdocs can learn from and connect to other female scientists in different stages of their careers. On those occasions, we not only invite scientists from Utrecht University but also well-known researchers from abroad, like Conny Aerts from the KU Leuven, Belgium, and first woman to recieve the Francqui Prize. For even broader outreach we organised a symposium on the Experiences of Gender in Academia with a keynote speaker from the Expertise Centre for Diversity Policy. This symposium was also used as an opportunity to improve the exchange with other female scientist networks like WISE from Delft, Netherlands, and WICS from Utrecht, Netherlands. The latter were also awarded with the diversity and inclusion award. 

You can be what you can see! 
Root distribution as function of litter layer management in eucalypt stands
Authors: Mendes Teixeira Ana Paula , Teixeira Pedro Paulo de C. , Almeida Luís Fernando J. , Silva Letícia C. F. , Silva Danilo H. S. , Stahl James , Paiva Haroldo N. de , Vergütz Leonardus , Silva Ivo R. da
Published: March 2020

The distribution of root system in the soil profile is an important factor for water and nutrient acquisition in planted forests. Harvest residue and litter layer management can alter nutrient availability to the plants, reflecting in shifts of root system distribution in the soil profile. In the present study, we aimed to evaluate the effect of litter layer management in root density and its correlation with depth, soil organic matter (SOM), and soil macro and micronutrients in fast-growing eucalypt plantations. We hypothesized that the presence of litter layer increases root density in the first soil layers while its absence results in higher root density in deeper soil layers. To this end we carried out an experiment in a eucalypt stand (Eucalyptus urophylla x Eucalyptus grandis; 3.3 x 1.82 m spacing; one-year-old trees) in the region of Telêmaco Borba, Paraná – Brazil. The Köppen climate classification is Cfb and the soil is classified as dystrophic Red Latosol. The treatments consisted of presence (+R) or absence (-R) of litter layer. The residue was composed by the previous rotation litter layer that remained in the forest after harvest. The experiment followed a randomized block design, with four replications. Root density (g dm-3) was evaluated in one representative tree per plot at each treatment and replication. We used a 5.3 cm diameter auger to collect root samples from 0-10, 10-20, 20-40 and 40-60 cm depths in seven predefined points in the planting row and interrow. For each sampling point and depth, roots were manually separated, washed to remove soil and other impurities, and subsequently oven dried at 65 °C to determine total dry mass. Additionally, SOM, soil macro and micronutrient contents were analyzed in each soil layer. Pearson’s correlation (α=5%) was performed between root density, depth, SOM, soil macro and micronutrients. Contrary to our hypothesis, the results showed that the presence of litter layer did not impacted root density in the superficial layer (0-20 cm), but resulted in a substantial increase of this trait in deeper soil layers (20-40 cm and 40-60 cm). The increase in root density observed for deeper soil layers was possibly a consequence of the higher nutrient availability favored by the presence of litter layer. The increase of root density in subsurface is important not only to increase tree water and nutrient use efficiency, but also to promote C sequestration in deeper soil layers. Our results highlight the importance of maintaining the litter layer in the field as reasonable strategy for a more sustainable management of fast-growing eucalypt forests.
Mountain wave parametrization in a transient gravity wave model
Authors: Kelemen Fanni Dora , Weinkaemmerer Jan , Bölöni Gergely , Achatz Ulrich
Published: March 2020

Orography induced gravity waves are investigated in a Multi Scale Gravity Wave Model (MS-GWaM) over idealized topography. MS-GWaM is a prognostic gravity-wave model, which parametrizes both the propagation and dissipation of subgrid-scale GWs. It is a Lagrangian ray-tracer model, which applies WKB-theory and calculates the propagation of ray volumes in spectral space. Its novelty is that not only the dissipative effect, but also the non-dissipative effects due to direct wave-mean flow interaction are captured. In our conceptual studies we investigate mountain wave generation, which is induced via a time-dependent large-scale wind encountering a prescribed topography. The framework used in our experiments is the PincFloit model, which integrates the pseudo-incompressible equations. We use it both in low resolution with MS-GWaM and in high resolution LES mode as a wave resolving reference. In the reference LES simulations the idealized topography, a mountain chain, is represented with an immersed boundary method. In the MS-GWaM experiments there is no resolved topography, but its effect is modelled as a lower boundary condition. The lower boundary condition is represented by initializing ray volumes with wave number and wave action density depending on the mountain characteristics and the large scale wind speed, based on the assumption that the flow follows the terrain. In the wave resolving reference experiments the flow does not strictly follow the terrain, but other instabilities (rotor formation, boundary layer separation) arise around the mountains. These processes decrease the available momentum transported by GWs, which was initially not accounted for in MS-GWaM. Thus an overestimation of wind deceleration was found in the MS-GWaM parametrization compared to the wave resolving simulation. To correct for this overestimation, an effective mountain height is introduced into Ms-GWaM, which is calculated by a scaling function between mountain height and flow properties using the Froude number.
Fire - climate interactions in a warming world
Authors: van der Werf Guido , Randerson James , Giglio Louis , van Wees Dave , Andela Niels , Veraverbeke Sander , Morton Douglas , Chen Yang
Published: March 2020

Elevated fire activity in 2019 across the arctic, Amazon, Australia, and other regions sparked a discussion about the role of climate change for the recent rise in biomass burning.  Given that drivers of fire vary widely between different fire types and regions, interpreting trends requires a regional breakdown of the global pattern. Our Global Fire Emissions Database (GFED) now provides nearly 25 years of consistent data and offers important insights into changing fire activity. The GFED record captures a global decline in burned area, driven mostly by reductions in savanna fires from fragmentation and land use change. The global declining trend is therefore driven by areas with relatively low fuel loads where fire often decreases during drought.  Here, we report on increasing fire trends in several other regions, which become even more apparent when proxy data from before the satellite era are included. Increasing trends are concentrated in areas with higher fuel loads that burn more easily under drought conditions, and where warming leads to increasing vapor pressure deficits that contribute to more extreme fire weather and higher combustion completeness values. Therefore, the rate of decline in fire emissions is less pronounced than that in burned area, and emissions of several reduced gases have actually increased over time. The historic time series provides important context for trends and drivers of regions that burned extensively in 2019, and moving beyond burned area to estimate fire emissions of greenhouse gases and aerosols is critical to assess how these events may feed back on climate change if trends continue.     
Assessing reasons for skilful predictions of winter windstorms over the Atlantic/European region
Authors: Degenhardt Lisa , Leckebusch Gregor , Scaife Adam
Published: March 2020

Severe Atlantic winter storms are affecting densely populated regions of Europe (e.g. UK, France, Germany, etc.). Consequently, different parts of the society, financial industry (e.g., insurance) and last but not least the general public are interested in skilful forecasts for the upcoming storm season (usually December to March). To allow for a best possible use of steadily improved seasonal forecasts, the understanding which factors contribute to realise forecast skill is essential and will allow for an assessment whether to expect a forecast to be skilful or not.

This study analyses the predictability of the seasonal forecast model of the UK MetOffice, the GloSea5. Windstorm events are identified and tracked following Leckebusch et al. (2008) via the exceedance of the 98th percentile of the near surface wind speed.

Seasonal predictability of windstorm frequency in comparison to observations (based e.g., on ERA5 reanalysis) are calculated and different statistical methods (skill scores) are compared.

Large scale patterns (e.g., NAO, AO, EAWR, etc.) and dynamical factors (e.g., Eady Growth Rate) are analysed and their predictability is assessed in comparison to storm frequency forecast skill. This will lead to an idea how the forecast skill of windstorms is depending on the forecast skill of forcing factors conditional to the phase of large-scale variability modes. Thus, we deduce information, which factors are most important to generate seasonal forecast skill for severe extra-tropical windstorms.

The results can be used to get a better understanding of the resulting skill for the upcoming windstorm season.