ALBERT

Description: GPS satellite observations indicate that in the tectonically complex eastern Mediterranean and east African regions microplates rotate counterclockwise with respect to the neighboring African plate. Using 3D numerical models, Glerum relates these observations of crustal deformation to the dynamics of the lithosphere and the underlying mantle that may cause this deformation. Glerum first describes her additions to the ASPECT software necessary for numerically modeling the upper mantle and lithosphere dynamics of convergent and divergent plate boundaries. These additions include the tracking of multiple materials with different physical properties and nonlinear viscous as well as viscoplastic rheologies. The implementations of complex, multi-material rheologies are verified with well-known 2D benchmarks and multi-material viscoplasticity is applied in 3D time-dependent thermomechanical models of oceanic subduction. Subsequently, Glerum uses ASPECT to investigate the sensitivity of horizontal surface motions to individual geodynamic processes in the eastern Mediterranean. Identification of all mantle drivers that should participate in modeling attempts to explain observations of crustal flow is essential to fully exploit the information contained by surface motions about their driving processes. Glerum therefore employs 3D data-driven instantaneous dynamics models of compressible flow including a complete set of possible mantle drivers of surface deformation. The reference instantaneous flow model results indicate that mantle processes can explain a large part of the crustal motion of the Aegean-Anatolian microplate. Subsequent systematic perturbations of model properties with respect to this reference model help estimate the individual contributions of tectonic plate motions, slab pull and trench suction, and density-induced mantle flow interacting with the slab and overlying plates while moderated by the mantle’s bulk viscosity. In order of regional importance, the predicted crustal flow of the Aegean-Anatolian region is most sensitive to slab pull, followed by slab-mantle interaction and basal drag, mantle rheology, and the absolute plate motion reference frame. Lastly, Glerum demonstrates a possible mechanism for the counterclockwise rotation of the Victoria microplate in the East African Rift System, which is in striking contrast to the clockwise motion of the surrounding plates. 3D models of the divergent system show that Victoria’s rotation can be caused by the drag of the African and Somalian plates along the strong edges of the microplate, while the rift segments along inherited lithospheric weaknesses facilitate Victoria’s rotation. The amount of rotation is therefore primarily controlled by the distribution of preexisting stronger regions and the weaker Precambrian mobile belts that surround Victoria. The induced counterclockwise rotation of the microplate leads to a clockwise shift of the local extension direction from E-W to more WNW-ESE along the overlapping rift branches. Comparison of the resulting predicted stress field and tectonic regimes to observations helps to elucidate the interpretation of local stress and strain indicators and to reconcile different opening models used to interpret the East African Rift System.

Description: Voxel representations have been used for years in scientific computation and medical imaging. The main focus of our research is to provide easy access to methods for making large-scale voxel models of built environment for environmental modelling studies while ensuring they are spatially correct, meaning they correctly represent topological and semantic relations among objects. In this article, we present algorithms that generate voxels (volumetric pixels) out of point cloud, curve, or surface objects. The algorithms for voxelization of surfaces and curves are a customization of the topological voxelization approach [1]; we additionally provide an extension of this method for voxelization of point clouds. The developed software has the following advantages: • It provides easy management of connectivity levels in the resulting voxels. • It is not dependant on any external library except for primitive types and constructs; therefore, it is easy to integrate them in any application. • One of the algorithms is implemented in C++ and C for platform independence and efficiency.

Description: Powered by WebGL, some renderers have recently become available for the visualization of point cloud data over the web, for example Plasio or Potree. We have extended Potree to be able to visualize massive point clouds and we have successfully used it with the second national Lidar survey of the Netherlands, AHN2, with 640 billion points. In addition to the visualization, the publicly available service at http://ahn2.pointclouds.nl/ also features a multi-resolution download tool, a geographic name search bar, a measurement toolkit, a 2D orientation map with field of view depiction, a demo mode and the tuning of the visualization parameters. Potree relies on reorganizing the point cloud data into an multi-resolution octree data structure. However, this reorganization is very time consuming for massive data sets. Hence, we have used a divide and conquer approach to decrease the octree creation time. To achieve such performance improvement we divided the entire space into smaller cells, generated an octree for each of them in a distributed manner and then we merged them into a single massive octree. The merging is possible because the extent of all the nodes of the octrees is known and fixed. All the developed tools are free and open-source (FOSS) and they can be used to visualize over the web other massive point clouds.

Description: The Science Platform at a glance In the new version of the German Sustainable Development Strategy, the Federal Government called on the scientific community to create a platform that is systematically involved in the steering, dialogue and implementation processes of the 2030 Agenda and its sustainability architecture. In response to this, the Science Platform Sustainability 2030 was launched on 8 May 2017 and was presented to the public one day later at the 13th BMBF Forum for Sustainability. The platform is supported by three organising institutions: the Sustainable Development Solutions Network Germany (SDSN Germany), the German Committee Future Earth (DKN Future Earth) and the Institute for Advanced Sustainability Studies (IASS), which houses the platform’s secretariat. A steering committee consisting of 26 members from science, the business community, and civil society is responsible for the platform’s activities and operative management. The committee also links the platform with other actors from science, politics, economics and civil society in an effort to build an effective, representative and internationally anchored platform. Additional support is provided by a circle of government agencies (open to all federal ministries) – currently including the BMBF, the BMUB, the BMZ, the BMEL and the Federal Chancellery.

Description: Green infrastructures play an essential role in urban planning, namely with their potential to reduce the impact from air pollution episodes together with extreme weather events. This chapter focuses on the assessment of green infrastructures’ benefits on current and future microclimate and air quality patterns in Porto’s urban area (Portugal). The effects of green infrastructures on flow dynamics are evaluated for the baseline scenarios by means of numerical and physical simulations, using the computational fluid dynamics (CFD) model VADIS and the wind tunnel of the University of Aveiro. The baseline morphological (BM) scenario focuses on the current morphological characteristics of Porto’s urban area, while a baseline green (BG) scenario comprises the replacement of built-up areas by green areas and parks. In addition, the benefits of green infrastructures on air quality are assessed for the baseline and under future climate scenarios. The air quality simulations focus on particulate matter, one of the most critical air pollutants with severe impacts on human health. For the BM scenario, the simulated concentrations are compared with hourly averaged PM10 concentrations measured during a weekday at the air quality station located within the study domain.

Description: The principles of responsibility and accountability have increasingly become a significant concept for the political capability to act independently and make decisions without superior authorization.

Description: Exposure to nitrogen dioxide (NO2) is associated with negative human health effects, both for short-term peak concentrations and from long-term exposure to a wider range of NO2 concentrations. For the latter, the European Union has established an air quality limit value of 40 µg m−3 as an annual average. However, factors such as proximity and strength of local emissions, atmospheric chemistry and meteorological conditions means that there is substantial variation in the hourly NO2 concentrations contributing to an annual average concentration. The aim of this analysis was to quantify the nature of this variation at thousands of monitoring sites across Europe through the calculation of a standard set of chemical climatology statistics. Specifically, at each monitoring site that satisfied data capture criteria for inclusion in this analysis, annual NO2 concentrations, as well as the percentage contribution from each month, hour of the day, and hourly NO2 concentrations divided into 5 µg m−3 bins were calculated. Across Europe, 2010–2014 average annual NO2 concentrations (NO2AA) exceeded the annual NO2 limit value at 8 % of 〉 2500 monitoring sites. The application of this chemical climatology approach showed that sites with distinct monthly, hour of day, and hourly NO2 concentration bin contributions to NO2AA were not grouped in specific regions of Europe, and within relatively small geographic regions there were sites with similar NO2AA, but with differences in these contributions. Specifically, at sites with highest NO2AA, there were generally similar contributions from across the year, but there were also differences in the contribution of peak vs moderate hourly NO2 concentrations to NO2AA, and from different hours across the day. Trends between 2000 and 2014 for 259 sites indicate that, in general, the contribution to NO2AA from winter months has increased, as has the contribution from the rush-hour periods of the day, while the contribution from peak hourly NO2 concentrations has decreased. The variety of monthly, hour of day and hourly NO2 contribution bin contributions to NO2AA, across cities, countries and regions of Europe indicate that within relatively small geographic areas different interactions between emissions, atmospheric chemistry and meteorology produce variation in NO2AA and the conditions that produce it. Therefore, measures implemented to reduce NO2AA in one location may not be as effective in others. The development of strategies to reduce NO2AA for an area should consider i) the variation in monthly, hour of day and hourly NO2 concentration bin contributions to NO2AA within that area, and ii) how specific mitigation actions will affect variability in hourly NO2 concentrations.

Description: If the detrimental impacts of human-induced climate change continue to mount, technologies for geoengineering our climate – i.e. deliberate modifying of the Earth's climate system at a large scale – are likely to receive ever greater attention from countries and societies worldwide. Geoengineering technologies could have profound ramifications for our societies, and yet agreeing on an international governance framework in which even serious research into these planetary-altering technologies can take place presents an immense international political challenge. In this important book, a diverse collection of internationally respected scientists, philosophers, legal scholars, policymakers, and civil society representatives examine and reflect upon the global geoengineering debate they have helped shape. Opening with essays examining the historic origins of contemporary geoengineering ideas, the book goes on to explore varying perspectives from across the first decade of this global discourse since 2006. These essays methodically cover: the practical and ethical dilemmas geoengineering poses; the evolving geoengineering research agenda; the challenges geoengineering technologies present to current international legal and political frameworks; and differing perceptions of geoengineering from around the world. The book concludes with a series of forward looking essays, some drawing lessons from precedents for governing other global issues, others proposing how geoengineering technologies might be governed if/as they begin to emerge from the lab into the real world.

Description: For more than 40 years, remote sensing satellite missions are globally scanning the earth´s surface. They are ideal instruments for monitoring spatio-temporal changes. A comprehensive analysis of this data has the potential to support solutions to major global change challenges related to climate change, population growth, water scarcity, or loss of biodiversity. However, a comprehensive analysis of these remote sensing data is a challenging task: (a) there is a lack of Big Data-adapted analysis tools, (b) the number of available sensors will steadily increase over the next years and (c) technological advancements allow to measure data at higher spatial, spectral, and temporal resolutions than ever before. These developments create an urgent need to better analyze huge and heterogeneous data volumes in support of e.g. global change research. The interdisciplinary research consortium of the “GeoMultiSens” project focuses on developing an open source, scalable and modular Big Data system that combines data from different sensors and analyzes data in the petabyte range (1015 Byte). The most important modules are: (1) data acquisition, (2) pre-processing and homogenization, (3) storage, (4) analysis, and (5) visual exploration. The data acquisition module enables users to specify a region and time interval of interest, to identify the available remote sensing scenes in different data archives, to assess how these scenes are distributed in space and time, and to decide which scenes to use for a specific analysis. The homogenization module uses novel and state-of-the-art algorithms that combine the selected remote sensing scenes from different sensors into a common data set. The data storage module optimises storage and processing of petabytes of data in a parallel and failure tolerant manner. The core technology of the data storage module is XtreemFS (http://www.xtreemfs.org). The analysis module implements image classification and time series analysis algorithms. The visual exploration module supports users in assessing the analysis results. All modules are adapted to a map-reduce processing scheme to allow a very fast information retrieval and parallel computing within the processing system Flink (http://flink.apache.org). Finally, a Visual Analytics approach integrates the individual modules and provides a visual interface to each step in the analysis pipeline. The Big Data system “GeoMultiSens” will store and process remotely sensed data from space-borne multispectral sensors of high and medium spatial resolution such as Sentinel-2, Landsat 5/7/8, Spot 1-6, ASTER, ALOS AVNIR-2 and RapidEye. Our poster presents the overall scientific concept of the Big Data system “GeoMultiSens” and technical details of the most important modules. We discuss scientific challenges of the Big Data system “GeoMultiSens” and present our ideas to address these scientific challenges.