Ole Peters and J. David Neelin
revised for Nature Physics, 2, 393-396, doi:10.1038/nphys314, 2006.
Paper (PDF 175 KB)
© Copyright 2006 by the Nature Publishing Group.
Abstract. Critical phenomena occur near continuous phase transitions. As a tuning parameter crosses its critical value, an order parameter increases as a power law. At criticality, order parameter fluctuations diverge and their spatial correlation decays as a power law1. Here we argue, using satellite data, that a critical value of water vapourmarks a non-equilibrium continuous phase transition to a regime of strong atmospheric convection and precipitation. Despite the complexity of atmospheric dynamics, we find important observables conform to the simple functional forms predicted by the theory of critical phenomena. In the atmosphere, the order parameter (precipitation) and tuning parameter (water vapour) are coupled. In systems where such coupling turns the critical point into an attractor, self-organized criticality (SOC) results2, 3. In meteorology the term ìquasi-equilibriumî (QE)4, refers to a balance between slow large-scale driving processes and rapid release of buoyancy by moist convection. Our study indicates that the attractive QE state, postulated long before SOC5, is the critical point of a continuous phase transition and is thus an instance of SOC.
Citation. Peters, O. and J. D. Neelin, 2006: Critical phenomena in atmospheric precipitation. Nature Physics, 2, 393-396, doi:10.1038/nphys314, 2006.