There are simple conceptual models of tropical cyclone intensification and potential intensity. However, such a framework has been lacking to describe the evolution of the outer circulation. An analytic growth model of the tropical cyclone outer size is derived from the angular momentum equation. The growth model fits a full-physics idealized tropical cyclone simulation. The lifecycle composite of the best-track outer size growth shows a strong super-linear nature, which supports an exponential growth as predicted by the growth model. The climatology of outer size growth measured by the radius of gale-force wind in the North Atlantic and Eastern Pacific during the period 2004–2017, can be understood in terms of four growth factors of the model: the initial size, the growth duration, the mean growth latitude, and the mean top-of-boundary-layer effective local inflow angle. All four variables are significantly different between the two basins. The observed lifetime maximum size follows a lognormal distribution, which is in line with the law of the proportionate effect of this exponential growth model. The growth model fits the observed outer size well in global basins. The time constant of the exponential size growth is approximately equal to the product of the Coriolis parameter and the mean effective inflow angle above the boundary layer. Further sensitivity experiments with the growth model suggest that the interannual variability of the global lifetime maximum size is largely driven by the variation of growth duration.

有热带气旋增强和潜在强度的简单概念模型。然而，一直缺乏这样的框架来描述外循环的演变。从角动量方程推导出热带气旋外径的解析增长模型。增长模型适合全物理理想化的热带气旋模拟。最佳轨道外部尺寸增长的生命周期组合显示出强大的超线性性质，支持增长模型预测的指数增长。2004-2017年北大西洋和东太平洋以强风半径测量的外径增长的气候学，可以从模型的四个增长因素来理解：初始规模、增长持续时间、平均生长纬度，和平均边界层顶部有效局部流​​入角。两个盆地之间的所有四个变量都存在显着差异。观察到的寿命最大尺寸服从对数正态分布，符合这种指数增长模型的比例效应规律。生长模型很好地拟合了全球盆地中观察到的外部尺寸。指数大小增长的时间常数大约等于科里奥利参数与边界层上方平均有效流入角的乘积。对生长模型的进一步敏感性实验表明，全球寿命最大尺寸的年际变化很大程度上是由生长持续时间的变化驱动的。观察到的寿命最大尺寸服从对数正态分布，符合这种指数增长模型的比例效应规律。生长模型很好地拟合了全球盆地中观察到的外部尺寸。指数大小增长的时间常数大约等于科里奥利参数与边界层上方平均有效流入角的乘积。对生长模型的进一步敏感性实验表明，全球寿命最大尺寸的年际变化很大程度上是由生长持续时间的变化驱动的。观察到的寿命最大尺寸服从对数正态分布，符合这种指数增长模型的比例效应规律。生长模型很好地拟合了全球盆地中观察到的外部尺寸。指数大小增长的时间常数大约等于科里奥利参数与边界层上方平均有效流入角的乘积。对生长模型的进一步敏感性实验表明，全球寿命最大尺寸的年际变化很大程度上是由生长持续时间的变化驱动的。指数大小增长的时间常数大约等于科里奥利参数与边界层上方平均有效流入角的乘积。对生长模型的进一步敏感性实验表明，全球寿命最大尺寸的年际变化很大程度上是由生长持续时间的变化驱动的。指数大小增长的时间常数大约等于科里奥利参数与边界层上方平均有效流入角的乘积。对生长模型的进一步敏感性实验表明，全球寿命最大尺寸的年际变化很大程度上是由生长持续时间的变化驱动的。