Mobile Disasters

Wandering: An Essay on Histories, Genders, Mobilities, and Forms

Dramatic alterations to the natural environment due to human activity have produced a permanent rupture in the Earth system; the relative stable epoch of the Holocene has given way to a volatile Anthropocene. Acceptance of these claims means that we now live in this altered physical reality, inviting us to rethink how we conceptualise disasters. Yet, disaster scholars have been hesitant to apply the Anthropocene label and to acknowledge the profound changes that it can bring to the study of disasters. This paper queries whether this label is a necessary adage or unnecessary baggage for disaster studies by examining the possibilities and the challenges associated with engaging with the Anthropocene. An analysis of the concepts, causes, and consequences of disasters reveals how the Anthropocene provides, as the very least, a theoretical heuristic for challenging linear temporal assumptions, the epistemological status of uncertainty, and the location of agency in disaster studies.

I have, with others, been seeking to transform or mobilize the social sciences and to promote what is increasingly called the 'new mobilities turn' or the 'new mobilities paradigm' (Urry, 2000, 2007).1 In that mobilities turn, one of the things that we are sure about is that mobilities are material and they presuppose material conditions under which people, objects, information, ideas and images move. The study of those movements, the form that they take and the often systemic character that they show are all part of the material aspects of the mobilities turn. In the journal Mobilities, almost all of the papers have some reflection upon the material character or bases of the movements that they address.

Automobilization as mobility paradigm. Reflections on cars, drivers and spatio-temporalities
 
 This article attempts to provide a theoretical contribution to ‘traffic and mobility sociology’. The article discusses three central dimensions of automobilization. The first is automobilization’s spatio-temporal context. Automobilization has opened the urban structure and liberated the individual from its physical limitations, while it has created a more dangerous and spread out structure, which constantly forces both humans and commodities to keep moving. The second dimension is the subject of automobilization. While the car has liberated the modern individual from spatio-temporal structures, it has embedded its users into a more mobile life form. The third dimension is the vehicles themselves. Cars are surprisingly alike in their structure, however they take on human characteristics. The article argues that automobilization has become reflexive. Under reflexive automobilization almost all ‘autosubjects’ are engaged in defining, interpreting and responding to the car’s environmental threats, not necessarily in a self-critical fashion. Rather their responses often merely lead to a reproduction of traditional ‘auto-spaces’.

This article reflects on the contributions of the late John Urry to sociology and to its spatial turn especially by developing the new mobilities paradigm. The proposition of this monograph issue of Current Sociology is that space has not yet been appropriately incorporated into sociology. But although partially true, Urry argued that this misses the significance of ‘the mobilities turn’ that swept through and incorporated the spatial turn within sociology but also within other disciplines. Tracing the spatial turn back to the 1980s, the article describes how the new mobilities paradigm grew out of and extended emerging theorizations of space. It argues that Urry’s work advanced a sociology of space though his focus on mobile spatializations and relational space. This included the distribution of agency between people, places, and material assemblages of connectivity; a broader shift in the spatial imagination of mobilities towards ‘non-representational’ social theory; the emergence of new methodologies that were more eclectic, experimental, creative, and linked to arts, design, and public policy; and lastly a renewed interest in geo-ecologies, the political economy of resource flows, and the global mobilities of energy, capital, and material objects as constitutive of spatial complexity. The new mobilities paradigm furthered the spatial turn in social sciences in many crucial ways, and John Urry’s body of work on mobilities and its influence on countless adjacent research areas have spread that spatial thinking far and wide.

It seems that a new paradigm is being formed within the social sciences, the ‘new mobilities’ paradigm. Some recent contributions to forming and stabilising this new paradigm include work from anthropology, cultural studies, geography, migration studies, science and technology studies, tourism and transport studies, and sociology. In this paper we draw out some characteristics, properties, and implications of this emergent paradigm, especially documenting some novel mobile theories and methods. We reflect on how far this paradigm has developed and thereby to extend and develop the ‘mobility turn’ within the social sciences.

The ability of any satellite gravity mission concept to monitor mass transport processes in the Earth system is typically tested well ahead of its implementation by means of various simulation studies. Those studies often extend from the simulation of realistic orbits and instrumental data all the way down to the retrieval of global gravity field solution time-series. Basic requirement for all these simulations are realistic representations of the spatio-temporal mass variability in the different sub-systems of the Earth, as a source model for the orbit computations. For such simulations, a suitable source model is required to represent (i) high-frequency (i.e., sub-daily to weekly) mass variability in the atmosphere and oceans, in order to realistically include the effects of temporal aliasing due to non-tidal high-frequency mass variability into the retrieved gravity fields. In parallel, (ii) low-frequency (i.e., monthly to interannual) variability needs to be modelled with realistic amplitudes, particularly at small spatial scales, in order to assess to what extent a new mission concept might provide further insight into physical processes currently not observable. The new source model documented here attempts to fulfil both requirements: Based on ECMWF’s recent atmospheric reanalysis ERA-Interim and corresponding simulations from numerical models of the other Earth system components, it offers spherical harmonic coefficients of the time-variable global gravity field due to mass variability in atmosphere, oceans, the terrestrial hydrosphere including the ice-sheets and glaciers, as well as the solid Earth. Simulated features range from sub-daily to multiyear periods with a spatial resolution of spherical harmonics degree and order 180 over a period of 12 years. In addition to the source model, a de-aliasing model for atmospheric and oceanic high-frequency variability with augmented systematic and random noise is required for a realistic simulation of the gravity field retrieval process, whose necessary error characteristics are discussed. The documentation is organized as follows: The characteristics of the updated ESM along with some basic validation are presented in Volume 1 of this report (Dobslaw et al., 2014). A detailed comparison to the original ESA ESM (Gruber et al., 2011) is provided in Volume 2 (Bergmann-Wolf et al., 2014), while Volume 3 (Forootan et al., 2014) contains a description of the strategy to derive a realistically noisy de-aliasing model for the high-frequency mass variability in atmosphere and oceans. The files of the updated ESA Earth System Model for gravity mission simulation studies are accessible at DOI:10.5880/GFZ.1.3.2014.001.

The ability of any satellite gravity mission concept to monitor mass transport processes in the Earth system is typically tested well ahead of its implementation by means of various simulation studies. Those studies often extend from the simulation of realistic orbits and instrumental data all the way down to the retrieval of global gravity field solution time-series. Basic requirement for all these simulations are realistic representations of the spatio-temporal mass variability in the different sub-systems of the Earth, as a source model for the orbit computations. For such simulations, a suitable source model is required to represent (i) high-frequency (i.e., subdaily to weekly) mass variability in the atmosphere and oceans, in order to realistically include the effects of temporal aliasing due to non-tidal high-frequency mass variability into the retrieved gravity fields. In parallel, (ii) low-frequency (i.e., monthly to interannual) variability needs to be modelled with realistic amplitudes, particularly at small spatial scales, in order to assess to what extent a new mission concept might provide further insight into physical processes currently not observable. The new source model documented here attempts to fulfil both requirements: Based on ECMWF’s recent atmospheric reanalysis ERA-Interim and corresponding simulations from numerical models of the other Earth system components, it offers spherical harmonic coefficients of the time-variable global gravity field due to mass variability in atmosphere, oceans, the terrestrial hydrosphere including the ice-sheets and glaciers, as well as the solid Earth. Simulated features range from sub-daily to multiyear periods with a spatial resolution of spherical harmonics degree and order 180 over a period of 12 years. In addition to the source model, a de-aliasing model for atmospheric and oceanic high-frequency variability with augmented systematic and random noise is required for a realistic simulation of the gravity field retrieval process, whose necessary error characteristics are discussed. The documentation of the updated ESA Earth System Model (updated ESM) for gravity mission simulation studies is organized as follows: The characteristics of the updated ESM along with some basic validation is presented in Volume 1. A detailed comparison to the original ESA ESM (Gruber et al., 2011) is provided in Volume 2, while Volume 3 contains the description of a strategy to derive realistic errors for the de-aliasing model of high-frequency mass variability in atmosphere and ocean.

While platial representations are being developed for sedentary entities, a parallel and useful endeavor would be to consider time in so-called “platio-temporal” representations that would also expand notions of mobility in GIScience, that are solely dependent on Euclidean space and time. Besides enhancing such aspects of place and mobility via spatio-temporal, we also include human aspects of these representations via considerations of the sociological notions of mobility via the mobilities paradigm that can systematically introduce representation of both platial information along with mobilities associated with ‘moving places.’ We condense these aspects into ‘platial mobility,’ a novel conceptual framework, as an integration in GIScience and the mobilities paradigm in sociology, that denotes movement of places in our platio-temporal and sociology-based representations. As illustrative cases for further study using platial mobility as a framework, we explore its benefits and methodological aspects toward developing better understanding for disaster management, disaster risk reduction and pandemics. We then discuss some of the illustrative use cases to clarify the concept of platial mobility and its application prospects in the areas of disaster management, disaster risk reduction and pandemics. These use cases, which include flood events and the ongoing COVID-19 pandemic, have led to displaced and restricted communities having to change practices and places, which would be particularly amenable to the conceptual framework developed in our work.

Ref lecting back on a little over a decade of research that has gathered under the banner of the “new mobilities paradigm” and “critical mobilities research,” it is a good time to ask what impact it has had on traditional disciplines such as sociology. Although sociologist John Urry’s work has been fundamental to challenging the “sedentarism” of sociological thought, sociology itself has been especially resistant to the “mobilities turn” as compared to other disciplines such as geography, transport studies and communication (though even in these disciplines the inroads are only partial). Following his book Sociology Beyond Societies (2000), Urry’s 2001 article “Mobile Sociology” in the British Journal of Sociology was re-printed in their special 60th anniversary edition (Urry 2010) as being one of the most agenda-setting articles of the decade. Yet there is scant evidence of that impact within the discipline of sociology itself: much of the impact has been on adjacent fields.

With the increasing availability of Earth observation datasets, developing methods for the identification of modes of variability is becoming crucial in Earth system science. These modes, also referred as teleconnections, are useful to understand the global climate system and to predict short-term climate and climate variability. For example, the El Niño–Southern Oscillation (ENSO) phenomenon, a teleconnection with global climate impacts, has been associated with major social, economic, and ecological consequences. In this study, a novel procedure called multichannel empirical orthogonal teleconnection (MEOT) analysis is introduced as a simple extension of the logic of empirical orthogonal teleconnections to uncover the temporal evolution of recurrent space–time patterns. A global monthly sea surface temperature dataset (1982–2007 time series) is used to explore the MEOT method and its differences and similarities with the multichannel singular spectrum analysis (MSSA). Both methods are applied with a 13-month embedding dimension to extract spatiotemporal patterns that exhibit clear basis vectors in quadrature. MSSA extracted four quadratures, and MEOT extracted three. Findings show that MEOT quadratures are more easily related to climate events corresponding to ENSO, South Atlantic Ocean dipole, and Atlantic meridional mode. MSSA identified one quadrature related to ENSO and one related to the quasi-biennial oscillation. The two remaining MSSA quadratures are mixtures of different indices rather than one climate event. Thus, results indicate that, since it does not suffer from a biorthogonality constraint, MEOT is effective at extracting modes of variability in climate datasets, suggesting its potential use in climate research.

ABSTRACTCirculation and other forms of temporary movement are of rising importance in the context of overall population mobility. Despite this, analysis is constrained by a lack of appropriate data and techniques for developing summary measures. Ethnographic methods have afforded useful insights into the complex space–time circuits and lifetime sequences involved, but without quantitative indicators these forms of mobility are effectively invisible to researchers and policy makers. Building on prior work in developing countries we advance methodologies for summarising the temporal dimension of circular mobility. Using illustrative data drawn from a variety of field studies among indigenous peoples in Australia we show how lifelines tracing individual mobility profiles can be used to generate systematic measures of frequency and duration. When plotted graphically these reveal distinctive periodicities that correspond to particular forms of mobility behaviour. Because these metrics are scalable and readily amenable to collection in general surveys they offer a unique bridge between the richness of detail that flows from biographic approaches and the aggregate metrics needed for statistical comparison. Copyright © 2011 John Wiley & Sons, Ltd.

SUMMARY Satellite gravity missions so far are medium size satellites consisting of one or a pair of satellites flying in near-polar or sun-synchronous orbital planes. Due to the limited observation geometry and the related space–time sampling, high-frequency non-tidal mass variation signals from atmosphere and ocean cannot be observed and cause temporal aliasing. For current single-pair satellite gravimetry missions as GRACE and GRACE Follow-On (GRACE-FO) temporal aliasing is the limiting factor and represents the major error source in the gravity field time-series. Adding a second inclined satellite pair to a GRACE-like polar pair (Bender constellation) currently is the most promising solution to increase the spatio-temporal resolution and to significantly reduce the temporal aliasing error. This shall be implemented with the MAGIC mission in future. With the ongoing developments in miniaturization of satellites and gravity-relevant instruments (accelerometers and intersatellite ranging), in future constellations of multiple small satellite pairs may solve this problem even beyond the capabilities of a Bender constellation. Therefore, in this study the capabilities of such constellations flying in specific formations are investigated in order to enable a retrieval of the temporal gravity field on short time scales. We assess the performance of up to 18 satellite pairs. The satellite configurations cover satellite pairs in polar and inclined orbits flying in pair-wise or pearl-string formation with varying mean anomalies and right ascensions of the ascending node (RAAN). As future potential miniaturized instruments optomechanical accelerometers with similar performance as those flying on GRACE-FO are a candidate, while for the intersatellite ranging instrument still some technological development is required. Therefore, in this study a microwave ranging system equivalent to the GRACE and GRACE-FO instruments performance is taken as baseline assuming that such instruments can be miniaturized in future as well. In numerical closed-loop simulations, up to nine different satellite configurations with up to 18 satellite pairs are evaluated based on the retrieval of the non-tidal temporal gravity field on a monthly basis. From the simulation results it is concluded that the best-performing satellite constellation of 18 polar satellite pairs already is outperformed by a typical Bender-like constellation of 1 polar and 1 inclined pair. In general, we identify that increasing the number of satellite pairs leads to an improved gravity field retrieval, either at low spherical harmonic degree and order (d/o) by the shift in RAAN or at high d/o by the shift in mean anomaly. By a two-step simulation approach, co-estimating also (sub-)daily gravity fields for selected configurations with a large number of satellite pairs distributed equally over the globe, it is possible to retrieve stand-alone gravity fields at 24, 12 and 6 hr temporal resolution. Ultimately it is concluded that a network of miniaturized satellites with instrument performances similar to GRACE-FO and flying in a well-defined constellation has the potential to observe (sub-)daily mass variations and therefore could drastically reduce the problem of temporal aliasing due to high frequency mass variations in the Earth system.

My work developed a kernel density estimator that well resolves typical structures of probability densities, which was demonstrated on a newly compiled marine data set of organic carbon-13 isotope ratios (δ13CPOC). All work was conducted within the emerging field of marine data science. I identified classical data science, a general understanding of ocean science, communication skills, and confidence as requirements for marine data scientists. In the beginning of my work, the existing δ13CPOC data consisted of about 500 data points in the global ocean. I expanded the existing data set to 4732 data points in a first version, and additionally to 6952 in a second. Both are published at PANGAEA along with meta information such as measurement location, time, and method, and interpolations. I have published a description of the temporal and geographic distribution of the first version at Earth System Science Data. I designed the development of the kernel density estimator algorithm on the existing concept of computing it as a solution of the diffusion equation. My algorithm uses finite differences in space and equidistant time steps with an implicit Euler method, and approximates the optimal smoothing parameter by two pilot steps. Compared to other well-known kernel density estimators, my algorithm produces reliable approximations of multimodal and boundary-close distributions on artificial and real marine data and is robust to noise. My implementation is published as a Python package on Zenodo, its description is submitted to Geoscientific Model Development. I was able to show that my kernel density estimator reliably evalu- ates ocean data and thus lays a foundation for calibrating Earth system models. At the same time, I was able to contribute to the definition and establishment of the field of Marine Data Science.

Abstract. This paper combines research and commentary to reinforce the importance of integrating hazard interactions and interaction networks (cascades) into multi-hazard methodologies. We present a synthesis of the differences between multi-layer single-hazard approaches and multi-hazard approaches that integrate such interactions. This synthesis suggests that ignoring interactions between important environmental and anthropogenic processes could distort management priorities, increase vulnerability to other spatially relevant hazards or underestimate disaster risk. In this paper we proceed to present an enhanced multi-hazard framework through the following steps: (i) description and definition of three groups (natural hazards, anthropogenic processes and technological hazards/disasters) as relevant components of a multi-hazard environment, (ii) outlining of three types of interaction relationship (triggering, increased probability, and catalysis/impedance), and (iii) assessment of the importance of networks of interactions (cascades) through case study examples (based on the literature, field observations and semi-structured interviews). We further propose two visualisation frameworks to represent these networks of interactions: hazard interaction matrices and hazard/process flow diagrams. Our approach reinforces the importance of integrating interactions between different aspects of the Earth system, together with human activity, into enhanced multi-hazard methodologies. Multi-hazard approaches support the holistic assessment of hazard potential and consequently disaster risk. We conclude by describing three ways by which understanding networks of interactions contributes to the theoretical and practical understanding of hazards, disaster risk reduction and Earth system management. Understanding interactions and interaction networks helps us to better (i) model the observed reality of disaster events, (ii) constrain potential changes in physical and social vulnerability between successive hazards, and (iii) prioritise resource allocation for mitigation and disaster risk reduction.