Bayesian analysis of interiors of HD 219134b, Kepler-10b, Kepler-93b, CoRoT-7b, 55 Cnc e, and HD 97658b using stellar abundance proxies

Using a generalized Bayesian inference method, we aim to explore the possible interior structures of six selected exoplanets for which planetary mass and radius measurements are available in addition to stellar host abundances: HD~219134b, Kepler-10b, Kepler-93b, CoRoT-7b, 55~Cnc~e, and HD~97658b. We aim to investigate the importance of stellar abundance proxies for the planetary bulk composition (namely Fe/Si and Mg/Si) on prediction of planetary interiors. We performed a full probabilistic Bayesian inference analysis to formally account for observational and model uncertainties while obtaining confidence regions of structural and compositional parameters of core, mantle, ice layer, ocean, and atmosphere. We determined how sensitive our parameter predictions depend on (1) different estimates of bulk abundance constraints and (2) different correlations of bulk abundances between planet and host star. [...] Although the possible ranges of interior structures are large, structural parameters and their correlations are constrained by the sparse data. The probability for the tested exoplanets to be Earth-like is generally very low. Furthermore, we conclude that different estimates of planet bulk abundance constraints mainly affect mantle composition and core size.Comment: Astronomy & Astrophysics, 597, A38 (15 pages, 9 figures

DIVA: An iterative method for building modular integrated models

Integrated modelling of global environmental change impacts faces the challenge that knowledge from the domains of Natural and Social Science must be integrated. This is complicated by often incompatible terminology and the fact that the interactions between subsystems are usually not fully understood at the start of the project. While a modular modelling approach is necessary to address these challenges, it is not sufficient. The remaining question is how the modelled system shall be cut down into modules. While no generic answer can be given to this question, communication tools can be provided to support the process of modularisation and integration. Along those lines of thought a method for building modular integrated models was developed within the EU project DINAS-COAST and applied to construct a first model, which assesses the vulnerability of the world’s coasts to climate change and sea-level-rise. The method focuses on the development of a common language and offers domain experts an intuitive interface to code their knowledge in form of modules. However, instead of rigorously defining interfaces between the subsystems at the project’s beginning, an iterative model development process is defined and tools to facilitate communication and collaboration are provided. This flexible approach has the advantage that increased understanding about subsystem interactions, gained during the project’s lifetime, can immediately be reflected in the model

Report on uncertainty methods

The issue of uncertainty is critical for climate change science and policy. A great deal of research analysis has gone into identifying the scope and character of uncertainty in climate change itself, in how analysts and assessment teams can and should communicate that uncertainty to policy- and decision-makers, and how policy- and decision-makers can then incorporate nowledge about the sources and magnitude of uncertainty in their choices. The primary purpose of this deliverable is to summarize that literature, and to synthesize it in a manner that is useful for the Mediation project, namely in improving the practice of assessing adaptaion needs and options, and in building a useful decision-support platform or system. The report starts with a user-driven focus, summarizing the literatures on both descriptive and normative models of decision-making under uncertainty, in order to identify the most effective and esential information inputs for each of these models. The report then summarizes some of the main guidance documents on communicating uncertanty, prepared for or in use by the Intergovernmental Panel on Climate Change, the United States government, and the Dutch government. Fially, the report synthesizes these previous studies for use in the Mediation project and its users by focusing on three essential characteristics of uncertainty communication: parsimony, personalization, and practicality. It identifies specific strategies for using these three criteria to ensure that assessments for climate adaptation are salient, credible, and legitimate, and thus ultimately construtive inputs into policy- and decision-making

Equilibrium distributions in thermodynamical traffic gas

We derive the exact formula for thermal-equilibrium spacing distribution of one-dimensional particle gas with repulsive potential V(r)=r^(-a) (a>0) depending on the distance r between the neighboring particles. The calculated distribution (for a=1) is successfully compared with the highway-traffic clearance distributions, which provides a detailed view of changes in microscopical structure of traffic sample depending on traffic density. In addition to that, the observed correspondence is a strong support of studies applying the equilibrium statistical physics to traffic modelling.Comment: 5 pages, 6 figures, changed content, added reference

Report on review of cross-sectoral impact of decisions and types of problems and contexts in which different dimensions of uncertainty play a role: An exploration of tipping points in climate policy responses

Adaptation to climate change is becoming increasingly necessary, with potentially severe climate-induced changes still ahead. Of key relevance for decision-making is the potential existence of points in time where the decision situation changes from one type to another because an impact threshold is exceeded. Such a change in the decision situation is, for instance, when the deciion shifts from being the concern of one actor or agency to multiple actors at multiple scales. We call these points adaptation crossroads. Their existence has important implications for adaptation decision support because they are where strategic and transformational adaptation decisions will have to be considered. We present three cases to explore adaptation crossroads and look at the implicatons fo scientific decision support. We draw some first conclusions, present a typology of adaptation crossoads, and lay groundwork for further inquiries into this area

Avoiding the avoidable: Towards a European heat waves risk governance

The death toll of recent heat waves in developed countries has been remarkably high, contradicting the common assumption that high levels of economic and technological development automatically lead to lower vulnerability to weather extremes. Future climate change may further increase this vulnerability. In this article we examine some recent evidence of heat wave-related mortality and we conclude that while economic wealth and technological capacity might be a necessary condition for adequately coping with adverse climate change effects, they are not sufficient. Questions of awareness, preparedness, organizational issues, and actor networks have to be addressed in a proactive and focused manner in order to avoid future heat wave damages. We propose some practical consequences for heat wave adaptation measures by adopting a risk governance framework that can be universally applied, as it is sufficiently flexible to deal with the multi-level and often fragmented reality of existing coping measures

Avoiding the avoidable: Towards a European heat waves risk governance

The death toll of recent heat waves in developed countries has been remarkably high, contradicting the common assumption that high levels of economic and technological development automatically lead to lower vulnerability to weather extremes. Future climate change may further increase this vulnerability. In this article we examine some recent evidence of heat wave-related mortality and we conclude that while economic wealth and technological capacity might be a necessary condition for adequately coping with adverse climate change effects, they are not sufficient. Questions of awareness, preparedness, organizational issues, and actor networks have to be addressed in a proactive and focused manner in order to avoid future heat wave damages. We propose some practical consequences for heat wave adaptation measures by adopting a risk governance framework that can be universally applied, as it is sufficiently flexible to deal with the multi-level and often fragmented reality of existing coping measures