Analysis of Hurricane Data Using the Variational Optimization Approach with a Dynamic Constraint

Abstract

The variational optimization technique is used to develop analysis equations for the high-energy portion of the hurricane. The specified functional contains an observational constraint, two low-pass filter terms, and a dynamic constraint, the gradient wind condition. The two nonlinear analysis equations resulting from the functional are solved simultaneously. That is, information contained in the pressure and wind fields as measured from an aircraft is used to determine the resulting gradient wind. These winds are illustrated for selected scales of motion in a total form as well as component form, i.e., contributions from pressure gradient, centrifugal and Coriolis terms. These results are then compared with those obtained by use of the analysis equation without the gradient wind constraint. Also, a comparison is made between the gradient wind computed from the analyzed pressure field and the analyzed wind speed profiles where the analysis equation respectively does and does not contain the gradient wind constraint. All analyzed fields referred to are those obtained by application of the set of derived analysis equations with the degree of filtering being dependent upon the relative weights applied to the various terms within the equation.