In Western Europe, several recent summers have been exceptionally warm, especially the summers of 2003 and 2015. Based on observations over the past century, meteorologists have come to see such major heat events as typically stemming from anticyclonic atmospheric circulation and a lack of spring rainfall in Southern Europe.
Economists routinely model how people choose between different options. For example, a common issue is time delay: would you choose to receive £100 today, or prefer £200 next month?
Any fractal set possesses a unique dimension, which characterises its self-similar behaviour under a change of scale. The attractors of many dynamical systems are more complex multifractals, which possess a spectrum of dimensions, or “generalized” dimensions.
The interaction of noise and non-linearity can cause sharp dynamical transitions, as appear in phenomena such as stochastic resonance or noise-induced synchronization or chaos.
In many areas of science and applied mathematics, important events often get initiated when a stochastic variable crosses a threshold value. Financial assets may be sold at a particular price, or a chemical reaction initiated when two particles come close enough.
Climate events linked to extremes of temperature (heatwaves/cold spells) have severe impacts on human health and natural ecosystems. Over the past few decades, the frequency and intensity of heatwaves have increased in Europe.
Here are links to a few recent articles by LML External Fellow Mark Buchanan.
Earth scientists have long known that fluid injected into the Earth’s crust can induce earthquakes. In principle, seismic activity may also be triggered through gas extraction through the mechanism of poroelastic stress perturbation, although such events have been observed less frequently.
Jet streams are narrow, fast-flowing westerly air currents located near the tropopause, the tropospheric boundary with the higher stratosphere. These jets play a major role in driving the large-scale atmospheric circulation and modulate the frequency, severity and persistence of weather events at middle latitudes.
The linear stability of large complex systems around their stationary points can be studied with random matrix theory. In one common model, the i.i.d. random matrix model, one assumes a simple statistical form for the interactions between distinct elements of a network.
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