Convectivity and Rotation of Entropicly Defined Clusters as a Measure of Hurricane and Tornado State

Abstract

A statistical physical model of the two basic properties of clusters within a hurricane--their convectivity and rotation--reveals a relationship for the time evolution of a hurricane. Non-doppler data from NEXRAD surface radar imagery, of Hurricane Irma transiting over Florida, is decomposed into unique clusters on the basis of an annealing process using entropy and energy differences between pixels. Application of the concept of entropic forces between a cluster's pixels, provides an estimate of the radial velocity of each cluster by application of Stokes' theorem. The ratio of the characteristic rotation and convectivity, associated with radial flow, integrated over the extent of the hurricane, closely tracks the hurricane's state, providing more time resolution than aircraft sorties alone allow. It is concluded that monitoring the rotational and convective state, in conjunction with the size of a cluster, is capable of quickly providing forecasters and others with changes in a hurricane's state. It is also shown that entropic tornado state can be similarly described in terms of convectivity and rotation rate.