Journal #9 - The Formula

Taking in to consideration all the responses I have received, I set out to create a formula for a hurricane energy index somewhere between ACE and IKE. Using four common data points of a tropical system (34kt wind radius, 50kt wind radius, 64kt wind radius, and maximum wind speed), I’ve developed a formula that takes into account both wind speed and storm size. One of the assumptions made in the creation of the formula was that winds increase in a linear fashion between wind radii – although this could be seen as simplistic, it is still accurate. The general form of the formula is as follows – the integral of (10^-4)*2pi*r*[(velocity of outer wind radius) x (outer radius – r)/(outer radius – inner radius) x (velocity of inner wind radius – velocity of outer wind radius)]^2 from outer radius to inner radius. In the formula, little r is the variable. The first part of the formula – the integral of 2pi*r – is the formula to find the area of a circle between any two radii. The second part of the formula (or, everything else) is the formula for determining the wind speed at any radius of the tropical cyclone. The wind speed is squared, as the formula for kinetic energy is ½ mv^2. In this formula mass and the coefficient ½ were not included because we are not interested in the actual kinetic energy of the cyclone – merely the amount of kinetic energy in the cyclone compared with other cyclones. Using this formula, you can find the entire kinetic energy of a cyclone based not only on the maximum wind speed, but also how far out the storm extends.