Figure S4: surface heatflux from the region of variable, eye-following radius broken into components based on the order of the sine series expansion around the eye.
Further investigation of constant-radius inner regions revealed similar results, intimating that the asymmetry in the eyewall region is an important characteristic of the storm to capture. The choice of scale for the eyewall-following inner region, set at 0.8 to 1.2 times the radius of maximum winds, was then set by the requirements of curve fitting the sine series around the radius, balancing the requirements for narrower spacing to capture higher order asymmetry and narrower band around the eyewall to minimize the influence of inner eye and rain band contamination of the eye signal.