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Remote sensing of geomagnetic fields and atomic collisions in the mesosphereFeb 09 2018Magnetic-field sensing has contributed to the formulation of the plate-tectonics theory, the discovery and mapping of underground structures on Earth, and the study of magnetism in other planets. Filling the gap between space-based and near-Earth observation, ... More

Implementation of a geometrically and energetically constrained mesoscale eddy parameterization in an ocean circulation modelFeb 08 2018The global stratification and circulation of the ocean and their sensitivities to changes in forcing depend crucially on the representation of the mesoscale eddy field. Here, a geometrically informed and energetically constrained parameterization framework ... More

Crossroads of the mesoscale circulationFeb 08 2018Quantifying the mechanisms of tracer dispersion in the ocean remains a central question in oceanography, for problems ranging from nutrient delivery to phytoplankton, to the early detection of contaminants. Until now, most of the analysis has been based ... More

An interview based study of pioneering experiences in teaching and learning Complex Systems in Higher EducationFeb 08 2018Due to the interdisciplinary nature of complex systems as a field, students studying complex systems at University level have diverse disciplinary backgrounds. This brings challenges (e.g. wide range of computer programming skills) but also opportunities ... More

The physics of climate change: simple models in climate scienceFeb 08 2018There is a perception that climate science can only be approached with complex computer simulations. But working climate scientists often use simple models to understand their simulations and make order-of-magnitude estimates. This article presents some ... More

Dynamic regulation of resource transport induces criticality in multilayer networks of excitable unitsFeb 06 2018Past work has shown that the function of a network of excitable units can be enhanced if the network is in the `critical regime', where excitations are, one average, neither damped nor amplified. In this Letter, we show that resource transport dynamics ... More

Kinematics of a Fluid Ellipse in a Linear FlowFeb 06 2018A four-parameter kinematic model for the position of a fluid parcel in a time-varying ellipse is introduced. For any ellipse advected by an arbitrary linear two-dimensional flow, the rates of change of the ellipse parameters are uniquely determined by ... More

Divergent Perspectives on Expert Disagreement: Preliminary Evidence from Climate Science, Climate Policy, Astrophysics, and Public OpinionFeb 06 2018We report the results of an exploratory study that examines the judgments of climate scientists, climate policy experts, astrophysicists, and non-experts (N = 3,367) about the factors that contribute to the creation and persistence of disagreement within ... More

Formation of eyes in large-scale cyclonic vorticesFeb 04 2018We present numerical simulations of steady, laminar, axisymmetric convection of a Boussinesq fluid in a shallow, rotating, cylindrical domain. The flow is driven by an imposed vertical heat flux and shaped by the background rotation of the domain. The ... More

Propelled micro-probes in turbulenceFeb 01 2018Feb 06 2018The temporal statistics of incompressible fluid velocity and passive scalar fields in developed turbulent conditions is investigated by means of direct numerical simulations along the trajectories of self-propelled point-like probes drifting in a flow. ... More

Landau-Ginzburg theory of cortex dynamics: Scale-free avalanches emerge at the edge of synchronizationJan 31 2018Understanding the origin, nature, and functional significance of complex patterns of neural activity, as recorded by diverse electrophysiological and neuroimaging techniques, is a central challenge in neuroscience. Such patterns include collective oscillations ... More

Temporal organization of magnetospheric fluctuations unveiled by recurrence patterns in the Dst indexJan 29 2018Magnetic storms constitute the most remarkable large-scale phenomena of nonlinear magnetospheric dynamics. Studying the dynamical organization of macroscopic variability in terms of geomagnetic activity index data by means of complexity measures provides ... More

Towards an automatic wind speed and direction profiler for Wide Field AO systemsJan 23 2018Wide Field Adaptive Optics (WFAO) systems are among the most sophisticated AO systems available today on large telescopes. The knowledge of the vertical spatio-temporal distribution of the wind speed (WS) and direction (WD) are fundamental to optimize ... More

Hurricane's Maximum Potential Intensity and the Gravitational Power of PrecipitationJan 21 2018The concept of Maximum Potential Intensity (MPI) is widely used in tropical cyclone research to estimate the minimum central pressure and the maximum velocity of tropical storms from environmental parameters. The MPI pressure derives from consideration ... More

A Tutorial on Modeling and Analysis of Dynamic Social Networks. Part IIJan 20 2018Recent years have witnessed a significant trend towards filling the gap between Social Network Analysis (SNA) and control theory. This trend was enabled by the introduction of new mathematical models describing dynamics of social groups, the development ... More

On the electrostatic field created at ground level by a haloJan 20 2018We investigate the effect of halo activity on the electrostatic field measured at ground level. We use electrostatic arguments as well as self-consistent simulations to show that, due to the screening charge in the ionosphere, the distant electrostatic ... More

Atmospheric Circulations of Hot Jupiters as Planetary Heat EnginesDec 20 2017Because of their intense incident stellar irradiation and likely tidally locked spin states, hot Jupiters are expected to have wind speeds that approach or exceed the speed of sound. In this work we develop a theory to explain the magnitude of these winds. ... More

The Mid-Pleistocene Transition induced by delayed feedback and bistabilityDec 20 2017The Mid-Pleistocene Transition, the shift from 41 kyr to 100 kyr glacial-interglacial cycles that occurred roughly 1 Myr ago, is often considered as a change in internal climate dynamics. Here we revisit the model of Quaternary climate dynamics that was ... More

Individuals, Institutions, and Innovation in the Debates of the French RevolutionOct 18 2017The French Revolution brought principles of "liberty, equality, and brotherhood" to bear on the day-to-day challenges of governing what was then the largest country in Europe. Its experiments provided a model for future revolutions and democracies across ... More

STAR: Spatio-Temporal Altimeter Waveform Retracking using Sparse Representation and Conditional Random FieldsSep 22 2017Satellite radar altimetry is one of the most powerful techniques for measuring sea surface height variations, with applications ranging from operational oceanography to climate research. Over open oceans, altimeter return waveforms generally correspond ... More

Stochastic parameterization identification using ensemble Kalman filtering combined with expectation-maximization and Newton-Raphson maximum likelihood methodsSep 21 2017For modelling geophysical systems, large-scale processes are described through a set of coarse-grained dynamical equations while small-scale processes are represented via parameterizations. This work proposes a method for identifying the best possible ... More

Was Doggerland catastrophically flooded by the Mesolithic Storegga tsunami?Jul 18 2017Myths and legends across the world contain many stories of deluges and floods. Some of these have been attributed to tsunami events. Doggerland in the southern North Sea is a submerged landscape thought to have been heavily affected by a tsunami such ... More

Why we live in hierarchies: a quantitative treatiseJul 06 2017This book is concerned with the various aspects of hierarchical collective behaviour which is manifested by most complex systems in nature. From the many of the possible topics, we plan to present a selection of those that we think are useful from the ... More

Statistical physics of human cooperationMay 19 2017Extensive cooperation among unrelated individuals is unique to humans, who often sacrifice personal benefits for the common good and work together to achieve what they are unable to execute alone. The evolutionary success of our species is indeed due, ... More

Light pollution offshore: zenithal sky glow measurements in the Mediterranean coastal watersMay 06 2017May 18 2017Light pollution is a worldwide phenomenon whose consequences for the natural environment and the human health are being intensively studied nowadays. Most published studies address issues related with light pollution inland. Coastal waters, however, are ... More

Impact of Solar Activity on the Ionosphere/Thermosphere during Geomagnetic Quiet Time for CTIPe and TIE-GCMJan 23 2017This study examines the impact that solar activity has on model results during geomagnetic quiet time for the ionosphere/thermosphere models: the Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics Model (CTIPe) and the Thermosphere-Ionosphere-Electrodynamics ... More

Evolving Powergrids in Self-Organized Criticality: An analogy with Sandpile and EarthquakesDec 07 2016The stability of powergrid is crucial since its disruption affects systems ranging from street lightings to hospital life-support systems. Nevertheless, large blackouts are inevitable if powergrids are in the state of self-organized criticality (SOC). ... More

Global attractor of the three dimensional primitive equations of large-scale ocean and atmosphere dynamics in an unbounded domainDec 07 2016This paper is concerned with the long-time behavior of solutions for the three dimensional primitive equations of large-scale ocean and atmosphere dynamics in an unbounded domain. Since the Sobolev embedding is no longer compact in an unbounded domain, ... More

Evolving network structure of academic institutionsDec 06 2016Today's colleges and universities consist of highly complex structures that dictate interactions between the administration, faculty, and student body. These structures can play a role in dictating the efficiency of policy enacted by the administration ... More

Isotopic profiles imply strong convective influence on water near the tropical tropopauseDec 06 2016The influence of deep convection on water vapor in the Tropical Tropopause Layer (TTL), the region just below the high ($\sim$18 km), cold tropical tropopause, remains an outstanding question in atmospheric science. Moisture transport to this region is ... More

Tropical Vorticity Forcing and Superrotation in the Spherical Shallow Water EquationsDec 06 2016The response of the nonlinear shallow water equations (SWE) on a sphere to tropical vorticity forcing is examined with an emphasis on momentum fluxes and the emergence of a superrotating (SR) state. Fixing the radiative damping and momentum drag timescales ... More

Modeling Structure and Resilience of the Dark NetworkDec 05 2016While the statistical and resilience properties of the Internet are no more changing significantly across time, the Darknet, a network devoted to keep anonymous its traffic, still experiences rapid changes to improve the security of its users. Here, we ... More

Clouds effect on the Atmospheric Total Column Carbon Dioxide Retrieval by Space Orbiting Argus 1000 Micro-spectrometer: Introductory StudyDec 04 2016Carbon Dioxide (CO2) is one of the most important greenhouse gases after water vapor (H2O) which plays significant role in the climate process. Accurate space-based measurement of CO2 is of great significance in inferring the location of CO2 sources and ... More

How Does the Antarctic Circumpolar Current Affect the Southern Ocean Meridional Overturning Circulation?Dec 04 2016The Meridional Overturning Circulation (MOC) in the Southern Ocean is investigated using hydrographic observations combined with satellite observations of sea-surface height. A three-dimensional (spatial and vertical) estimate of the isopycnal eddy-diffusivity ... More

Stochastic Longshore Current DynamicsDec 04 2016We develop a stochastic parametrization, based on a `simple' deterministic model for the dynamics of steady longshore currents, that produces ensembles that are statistically consistent with field observations of these currents. Unlike deterministic models, ... More

Primordial Sex Facilitates the Emergence of EvolutionDec 02 2016Compartments are ubiquitous throughout biology, yet their importance stretches back to the origin of cells. In the context of origin of life, we assume that a protocell, a compartment enclosing functional components, requires $N$ components to be evolvable. ... More

Optical turbulence forecast: ready for an operational applicationDec 02 2016One of the main goals of the feasibility study MOSE (MOdellig ESO Sites) is to evaluate the performances of a method conceived to forecast the optical turbulence above the ESO sites of the Very Large Telescope and the European-Extremely Large Telescope ... More

Variable phase propagation velocity for long-range lightning location systemDec 02 2016The electromagnetic wave propagation velocity at low radio frequencies is an important input parameter for lightning location systems that use time of arrival (TOA) method. This velocity is normally fixed at or near the speed of light. However, this study ... More

Connecting Harbours. A comparison of traffic networks across ancient and medieval EuropeNov 29 2016Ancient and medieval harbours connected via navigable and terrestrial routes could be interpreted as elements of complex traffic networks. Based on evidence from three projects in Priority Programme 1630 (Fossa Carolina, Inland harbours in Central Europe ... More

An Optical Atmospheric Phenomenon Observed in 1670 over the City of Astrakhan Was not a Mid-Latitude AuroraNov 28 2016It has been recently claimed (Zolotova and Ponyavin, Solar Phys., 291, 2869, 2016, ZP16 henceforth) that a mid-latitude optical phenomenon, which took place over the city of Astrakhan in July 1670, according to Russian chronicles, was a strong aurora ... More

Locally-orthogonal unstructured grid-generation for general circulation modelling on the sphereNov 28 2016Dec 02 2016An algorithm for the generation of non-uniform, locally-orthogonal staggered unstructured grids on spheroidal geometries is described. This technique is designed to generate high-quality staggered Voronoi/Delaunay dual meshes appropriate for general circulation ... More

Locally-orthogonal, unstructured grid-generation for general circulation modelling on the sphereNov 28 2016An algorithm for the generation of non-uniform, locally-orthogonal staggered unstructured grids on spheroidal geometries is described. This technique is designed to generate high-quality staggered Voronoi/Delaunay dual meshes appropriate for general circulation ... More

Flow Regimes of Mesoscale Circulations Forced by Inhomogeneous Surface HeatingNov 27 2016Urbanization is one of the extreme process that increases uncertainty in future climate projections. Flow regimes of mesoscale circulations associated with surface heating due to urbanization have been investigated using a wavelet based computational ... More

A model of the best-of-N nest-site selection process in honeybeesNov 22 2016The ability of a honeybee swarm to select the best nest site plays a fundamental role in determining the future colony's fitness. To date, the nest-site selection process has mostly been modelled and theoretically analysed for the case of binary decisions. ... More

Rhythms of the collective brain: Metastable synchronization and cross-scale interactions in connected multitudesNov 21 2016Collective social events operate at many levels of organization -- from individuals to crowds -- presenting a variety of temporal and spatial scales of activity, whose causal interactions challenge our understanding of social systems. Large data sets ... More

Percolation framework to describe El Niño conditionsNov 18 2016Complex networks have been used intensively to investigate the flow and dynamics of many natural systems including the climate system. Here, we develop a percolation based measure, the order parameter, to study and quantify climate networks. We find that ... More

Biodiversity in models of cyclic dominance is preserved by heterogeneity in site-specific invasion ratesNov 17 2016Global, population-wide oscillations in models of cyclic dominance may result in the collapse of biodiversity due to the accidental extinction of one species in the loop. Previous research has shown that such oscillations can emerge if the interaction ... More

A Socio-geographic Perspective on Human Activities in Social MediaNov 17 2016Location-based social media make it possible to understand social and geographic aspects of human activities. However, previous studies have mostly examined these two aspects separately without looking at how they are linked. The study aims to connect ... More

Prediction of Seasonal Temperature Using Soft Computing Techniques: Application in Benevento (Southern Italy) AreaNov 15 2016In this work two soft computing methods, Artificial Neural Networks and Genetic Programming, are proposed in order to forecast the mean temperature that will occur in future seasons. The area in which the soft computing techniques were applied is that ... More

Collective navigation of complex networks: Participatory greedy routingNov 14 2016Many networks are used to transfer information or goods, in other words, they are navigated. The larger the network, the more difficult it is to navigate efficiently. Indeed, information routing in the Internet faces serious scalability problems due to ... More

Emergent pattern formation in an interstitial biofilmNov 14 2016Collective behavior of bacterial colonies plays critical roles in adaptability, survivability, biofilm expansion and infection. We employ an individual-based model of an interstitial biofilm to study emergent pattern formation based on the assumptions ... More

The 2016 Al-Mishraq sulphur plant fire: source and risk area estimationNov 11 2016On October 20:th 2016, Daesh (Islamic State) set fire to the sulphur production site Al-Mishraq as the battle of Mosul became more intense. A huge plume of toxic sulphur dioxide and hydrogen sulphide caused comprising casualties. The intensity of the ... More

The 2016 Al-Mishraq sulphur plant fire: source and risk area estimationNov 11 2016Nov 17 2016On October 20th 2016, Daesh (Islamic State) set fire to the sulphur production site Al-Mishraq as the battle of Mosul became more intense. A huge plume of toxic sulphur dioxide and hydrogen sulphide caused comprising casualties. The intensity of the release ... More

The 2016 Al-Mishraq sulphur plant fire: source and risk area estimationNov 11 2016Nov 14 2016On October 20th 2016, Daesh (Islamic State) set fire to the sulphur production site Al-Mishraq as the battle of Mosul became more intense. A huge plume of toxic sulphur dioxide and hydrogen sulphide caused comprising casualties. The intensity of the release ... More

Has global warming modified the relationship between sunspot numbers and global temperatures?Nov 11 2016We study time evolution of the relationship between sunspot numbers and global temperatures between 1880 and 2016 using wavelet coherence framework. The results suggest that the relationship is stable in time. Changes in the sunspot numbers precede changes ... More

The impact of anticipation in dynamical systemsNov 11 2016The flocking of animals is often modelled as a dynamical system, in which individuals are represented as particles whose interactions are determined by the current state of the system. Many animals, however, including humans, have predictive capabilities, ... More

Synergistic Dynamic Theory of Complex Coevolutionary Systems: Disentangling Nonlinear Spatiotemporal Controls on PrecipitationNov 10 2016We formulate a nonlinear synergistic theory of coevolutionary systems, disentangling and explaining dynamic complexity in terms of fundamental processes for optimised data analysis and dynamic model design: Dynamic Source Analysis (DSA). DSA provides ... More

Effects of additive noise on the stability of glacial cyclesNov 10 2016It is well acknowledged that the sequence of glacial-interglacial cycles is paced by the astronomical forcing. However, how much is the sequence robust against natural fluctuations associated, for example, with the chaotic motions of atmosphere and oceans? ... More

Geophysical flows under location uncertainty, Part III: SQG and frontal dynamics under strong turbulence conditionsNov 09 2016Models under location uncertainty are derived assuming that a component of the velocity is uncorrelated in time. The material derivative is accordingly modified to include an advection correction, inhomogeneous and anisotropic diffusion terms and a multiplicative ... More

Geophysical flows under location uncertainty, Part II: Quasi-geostrophy and efficient ensemble spreadingNov 09 2016Models under location uncertainty are derived assuming that a component of the velocity is uncorrelated in time. The material derivative is accordingly modified to include an advection correction, inhomogeneous and anisotropic diffusion terms and a multiplicative ... More

Scale-selective dissipation in energy-conserving finite element schemes for two-dimensional turbulenceNov 08 2016We analyse the multiscale properties of energy-conserving upwind-stabilised finite element discretisations of the two-dimensional incompressible Euler equations. We focus our attention on two particular methods: the Lie derivative discretisation introduced ... More

Interaction between global-scale atmospheric vortices: Modeling with Hamiltonian dynamic system of antipodal point vortices on a rotating sphereNov 07 2016We get point vortices dynamics equations on a rotating sphere surface directly from the hydrodynamic equations as representing their weak exact solution contrary to the conventional case of the use of a kinematic relationship between a given singular ... More

Practical scalability assesment for parallel scientific numerical applicationsNov 05 2016The concept of scalability analysis of numerical parallel applications has been revisited, with the specific goals defined for the performance estimation of research applications. A series of Community Climate Model System (CCSM) numerical simulations ... More

Downburst Prediction Applications of GOES over the Western United StatesNov 04 2016Over the western United States, the hazards posed to aviation operations by convective storm-generated downbursts have been extensively documented. Other significant hazards posed by convective downbursts over the intermountain western U.S. include the ... More

Improved weather generator algorithm for multisite simulation of precipitation and temperatureNov 04 2016The KnnCAD Version 4 weather generator algorithm for nonparametric, multisite simulations of temperature and precipitation data is presented. The K-nearest neighbour weather generator essentially reshuffles the historical data, with replacement. In KnnCAD ... More

Sensitive dependence of network dynamics on network structureNov 03 2016The relation between network structure and dynamics is determinant for the behavior of complex systems in numerous domains. An important longstanding problem concerns the properties of the networks that optimize the dynamics with respect to a given performance ... More

Statistical Mechanics and the Climatology of the Arctic Sea Ice Thickness DistributionNov 03 2016We study the seasonal changes in the thickness distribution of Arctic sea ice, $g(h)$, under climate forcing. Our analytical and numerical approach is based on a Fokker-Planck equation for $g(h)$ (Toppaladoddi \& Wettlaufer \emph{Phys. Rev. Lett.} {\bf ... More

Noise induced pattern formation of oscillation growth in traffic flowNov 02 2016Noise is able to induce diverse patterns in physical and interdisciplinary extended systems. This Letter investigates the role of noise in pattern formation of traffic flow, which is a typical self-driven system far from equilibrium. We demonstrate that ... More

High-resolution annual maps of whole system mangrove carbon stocks from 2000 to 2012Nov 01 2016Mangrove forests store high densities of organic carbon compared to other forested ecosystems1. Such high carbon storage coupled with their rate of deforestation means that mangroves can contribute to global carbon emissions and are candidates for Payments ... More

Noctilucent Cloud Particle Size Determination based on Multi-Wavelength All-Sky AnalysisOct 31 2016The article deals with the analysis of color distribution in noctilucent clouds (NLC) in the sky based on multi-wavelength (RGB) CCD-photometry provided with the all-sky camera in Lovozero in the north of Russia (68.0 deg N, 35.1 deg E) during the bright ... More

The interaction of seasonality and low-frequencies in a stochastic Arctic sea ice modelOct 31 2016The stochastic Arctic sea ice model described as a single periodic non-autonomous stochastic ordinary differential equation (ODE) is useful in explaining the seasonal variability of Arctic sea ice. However, to be nearer to realistic approximations we ... More

Generalized fluid theory including non-Maxwellian kinetic effectsOct 30 2016The results obtained by the plasma physics community for the validation and the prediction of turbulence and transport in magnetized plasma come mainly from the use of very CPU-consuming particle-in-cell or (gyro)kinetic codes which naturally include ... More

Reduced-order prediction of rogue waves in two-dimensional deep-water wavesOct 29 2016We consider the problem of large wave prediction in two-dimensional water waves. Such waves form due to the synergistic effect of dispersive mixing of smaller wave groups and the action of localized nonlinear wave interactions that leads to focusing. ... More

Fluctuations When Driving Between Nonequilibrium Steady StatesOct 29 2016Maintained by environmental fluxes, biological systems are thermodynamic processes that operate far from equilibrium without detailed-balance dynamics. Yet, they often exhibit well defined nonequilibrium steady states (NESSs). More importantly, critical ... More

Increased methane emissions from deep osmotic and buoyant convection beneath submarine seeps as climate warmsOct 28 2016High speeds have been measured at seep and mud-volcano sites expelling methane-rich fluids from the seabed. Thermal or solute-driven convection alone cannot explain such high velocities in low-permeability sediments. Here, we demonstrate that in addition ... More

The role of viscosity contrast on plume structure in laboratory modeling of mantle convectionOct 28 2016We have conducted laboratory experiments to model important aspects of plumes in mantle convection. We focus on the role of the viscosity ratio U (between the ambient fluid and the plume fluid) in determining the plume structure and dynamics. In our experiments, ... More

The reliable solution and computation time of variable parameters Logistic modelOct 27 2016The reliable computation time (RCT, marked as Tc) when applying a double precision computation of a variable parameters logistic map (VPLM) is studied. First, using the method proposed, the reliable solutions for the logistic map are obtained. Second, ... More

Pressure-dependent water absorption cross sections for exoplanets and other atmospheresOct 27 2016Many atmospheres (cool stars, brown dwarfs, giant planets, extrasolar planets) are predominately composed of molecular hydrogen and helium. H$_2{}^{16}$O is one of the best measured molecules in extrasolar planetary atmospheres to date and a major compound ... More

Wall modeling via function enrichment within a high-order DG method for RANS simulations of incompressible flowOct 26 2016We present a novel approach to wall modeling for RANS within the discontinuous Galerkin method. Wall functions are not used to prescribe boundary conditions as usual but they are built into the function space of the numerical method as a local enrichment, ... More

Mesoscale circulation along the Sakhalin Island eastern coastOct 26 2016The seasonal and interannual variability of mesoscale circulation along the eastern coast of the Sakhalin Island in the Okhotsk Sea is investigated using AVISO velocity field and oceanographic data for the period from 1993 to 2016. It is found that mesoscale ... More

Analysis of mesoscale forecasts using ensemble methodsOct 24 2016Mesoscale forecasts are now routinely performed as elements of operational forecasts and their outputs do appear convincing. However, despite their realistic appearance at times the comparison to observations is less favorable. At the grid scale these ... More

Coherent changes of the circulation in the deep North Atlantic from moored transport arraysOct 21 2016In situ boundary arrays have been installed in the North Atlantic to measure the large-scale ocean circulation. Here, we use measurements at the western edge of the North Atlantic at $16^\circ$N and $26^\circ$N to investigate low-frequency variations ... More

Detecting Rainfall Onset Using Sky ImagesOct 21 2016Ground-based sky cameras (popularly known as Whole Sky Imagers) are increasingly used now-a-days for continuous monitoring of the atmosphere. These imagers have higher temporal and spatial resolutions compared to conventional satellite images. In this ... More

Unveiling the Multi-fractal Structure of Complex NetworksOct 21 2016The fractal nature of graphs has traditionally been investigated by using the nodes of networks as the basic units. Here, instead, we propose to concentrate on the graph edges, and introduce a practical and computationally not demanding method for revealing ... More

An analytical model of iceberg driftOct 20 2016Iceberg drift and decay and the associated freshwater release are increasingly seen as important processes in Earth's climate system, yet a detailed understanding of their dynamics has remained elusive. Here, an idealized model of iceberg drift is presented. ... More

Wave turbulence in a two-layer fluid: coupling between free surface and interface wavesOct 19 2016We experimentally study gravity-capillary wave turbulence on the interface between two immiscible fluids of close density with free upper surface. We locally measure the wave height at the interface between both fluids by means of a highly sensitive laser ... More

Foot force models of crowd dynamics on a wobbly bridgeOct 17 2016Modern pedestrian and suspension bridges are designed using industry-standard packages, yet disastrous resonant vibrations are observed, necessitating multi-million dollar repairs. Recent examples include pedestrian induced vibrations during the openings ... More

Sensitivity of Complex NetworksOct 17 2016The sensitivity (i.e. dynamic response) of complex networked systems has not been well understood, making difficult to predict whether new macroscopic dynamic behavior will emerge even if we know exactly how individual nodes behave and how they are coupled. ... More

Kinetic description of collision avoidance in pedestrian crowds by sidesteppingOct 17 2016In this paper we study a kinetic model for pedestrians, who are assumed to adapt their motion towards a desired direction while avoiding collisions with others by stepping aside. These minimal microscopic interaction rules lead to complex emergent macroscopic ... More

Localization in High-Dimensional Monte Carlo FilteringOct 12 2016The high dimensionality and computational constraints associated with filtering problems in large-scale geophysical applications are particularly challenging for the Particle Filter (PF). Approximate but efficient methods such as the Ensemble Kalman Filter ... More

Oscillations in two-person avoidance controlOct 12 2016Oct 31 2016Social interaction dynamics are a special type of group interactions that play a large part in our everyday lives. They dictate how and with whom a certain individual will interact. One of such interactions can be termed "avoidance control". This everyday ... More

Oscillations in two-person avoidance controlOct 12 2016Social interaction dynamics are a special type of group interactions that play a large part in our everyday lives. They dictate how and with whom a certain individual will interact. One of such interactions can be termed "avoidance control". This everyday ... More

Sampling errors of quantile estimations from finite samples of dataOct 11 2016Empirical relationships are derived for the expected sampling error of quantile estimations using Monte Carlo experiments for two frequency distributions frequently encountered in climate sciences. The relationships found are expressed as a scaling factor ... More

HELIOS-Retrieval: An Open-source, Nested Sampling Atmospheric Retrieval Code, Application to the HR 8799 Exoplanets and Inferred Constraints for Planet FormationOct 11 2016We present an open-source retrieval code named HELIOS-Retrieval (hereafter HELIOS-R), designed to obtain chemical abundances and temperature-pressure profiles from inverting the measured spectra of exoplanetary atmospheres. In the current implementation, ... More

Manifest and Subtle Cyclic Behavior in Nonequilibrium Steady StatesOct 10 2016Many interesting phenomena in nature are described by stochastic processes with irreversible dynamics. To model these phenomena, we focus on a master equation or a Fokker-Planck equation with rates which violate detailed balance. When the system settles ... More

Stable components of sound fields in the oceanOct 08 2016A method is proposed for finding the wave field components which are weakly sensitive to the sound speed perturbation in the ocean acoustic waveguides. Such a component is formed by a narrow beam of rays whose spread in vertical direction, up to the observation ... More

Flexible Dynamics of Two Quorum Sensing Coupled RepressilatorsOct 07 2016Genetic oscillators play important roles in cell life regulation. The regulatory efficiency usually depends strongly on the emergence of stable collective dynamic modes, which requires designing the interactions between genetic networks. We investigate ... More

Gusts and Shear Within Hurricane Eyewalls Can Exceed Offshore Wind-Turbine Design StandardsOct 03 2016Offshore wind energy development is underway in the U.S., with proposed sites located in hurricane-prone regions. Turbine design criteria outlined by the International Electrotechnical Commission do not encompass the extreme wind speeds and directional ... More

Emergent eddy saturation from an energy constrained eddy parameterisationOct 03 2016The large-scale features of the global ocean circulation and the sensitivity of these features with respect to forcing changes are critically dependent upon the influence of the mesoscale eddy field. One such feature, observed in numerical simulations ... More

On the astronomical origin of the Hallstatt oscillation found in radiocarbon and climate records throughout the HoloceneOct 03 2016An oscillation with a period of about 2100-2500 years, the Hallstatt cycle, is found in cosmogenic radioisotopes (C-14 and Be-10) and in paleoclimate records throughout the Holocene. Herein we demonstrate the astronomical origin of this cycle. Namely, ... More