Using Extreme Value Theory to Characterize Chaotic Dynamics

In the analysis of dynamical systems, the correlation dimension is a useful indicator describing the fractal structure of invariant sets. Other measures, such as the Lyapunov exponents and the entropy, provide complementary information on the time scale of predictability of the system. Read more

Characterizing local energy transfers in atmospheric flows

Computational models employed for simulations of weather and climate have limited spatial resolution, currently around 2 km for regional weather models and 100 km for global climate models. Read more

Large deviation theory for diluted Wishart random matrices

Modern computing technology has brought about the era of Big Data, and a host of new challenges concerning how to analyse high-dimensional data for problems ranging from studies of climate to genetics, biomedical imaging to economics. Read more

Switching dynamics in atmospheric flow

The jet stream is a band of air that flows around the Earth at high-altitude, moving West to East in mid-latitude regions. This so-called “zonal” flow typically has cyclones and anticyclones embedded within it, which last for a few days. Read more

Small Cities Face Greater Impact From Automation

Cities are modern society’s hubs for economic productivity and innovation, and now accommodate over half of the world’s population. As job migration is the leading factor in urbanization, policymakers are increasingly concerned about the likely impact of artificial intelligence and automation on city employment. Read more

Scaling Behaviour in Mathematical Models of Aggregation

The rings of Saturn are among the most spectacular structures in our solar system, made up of innumerable fragments of ice and rock ranging in size from metres to millimetres. The stability of the rings is a matter of some debate among planetary scientists. Read more

Sampling the Dynamical Properties of Northern Hemisphere Atmospheric Fields Over the Past 60 Years

Solar radiation and the earth’s rotation are the primary drivers of large-scale atmospheric motions, while turbulence adds a layer of complexity at small scales. This picture is further complicated by ocean–land interactions, vegetation, anthropocentric forcing, and the hydrological cycle. Read more

A Novel Model to Simulate Biological Cell Migration

In recent years evidence has accumulated that single biological cells often move in a way that is unlike Brownian motion, a paradigmatic model of random dynamics. Instead, cells migrate faster and exhibit so-called superdiffusion. This article reports on a new method to efficiently simulate superdiffusively moving cells. Read more

Comparison of shortest and fastest routes through cities reveals a structural typology of city development

Much is known about the geometry of road networks within cities, and how these vary with city size and level of economic development. Less is known about how these structures influence the flows of people and activity within cities, and how that activity in turn feeds back to shape road network geometry. Read more