Supplementary tropical-cyclone count data-set for ‘Stratified statistical models of North Atlantic basin-wide and regional tropical cyclone counts’ (Journal of Geophysical Research, Kozar et al. 2012)

Using the historical Atlantic tropical cyclone record, this study examines the empirical relationships between climate state variables and Atlantic tropical cyclone counts. The state variables considered as predictors include indices of the El Niño/Southern Oscillation and Northern Atlantic Oscillation, and both “local” and “relative” measures of Main Development Region sea surface temperature. Other predictors considered include indices measuring the Atlantic Meridional Mode and the West African monsoon. Using all of the potential predictors in a forward stepwise Poisson regression, we examine the relationships between tropical cyclone counts and climate state variables. As a further extension on past studies, both basin-wide named storm counts and cluster analysis time series representing distinct flavors of tropical cyclones, are modeled. A wide variety of cross validation metrics reveal that basin-wide counts or sums over appropriately chosen clusters may be more skillfully modeled than the individual cluster series. Ultimately, the most skillful models typically share three predictors: indices for the main development region sea surface temperatures, the El Niño/Southern Oscillation, and the North Atlantic Oscillation.

本研究基于大西洋热带气旋历史观测资料，探究气候状态变量与大西洋热带气旋生成数量之间的经验关联。本研究选取的预测因子包括厄尔尼诺/南方涛动（El Niño/Southern Oscillation）、北大西洋涛动（Northern Atlantic Oscillation）指数，以及大西洋主要发展区（Main Development Region）海表温度（sea surface temperature）的“局地”与“相对”度量指标；其余候选预测因子还涵盖大西洋经向模（Atlantic Meridional Mode）指数与西非季风（West African monsoon）指数。本研究通过正向逐步泊松回归（forward stepwise Poisson regression）纳入全部潜在预测因子，分析热带气旋生成数量与气候状态变量间的关联关系。相较于过往研究，本研究进一步拓展了建模范畴：既针对全洋面命名风暴数量开展建模，也对表征不同类型热带气旋的聚类分析（cluster analysis）时间序列进行拟合。多项交叉验证（cross validation）指标结果显示，相较于单个聚类序列，在恰当选取聚类簇后，全洋面风暴总数或聚类簇总和的建模拟合效果更为优异。最终，表现最优的模型通常共享三类核心预测因子：大西洋主要发展区海表温度指数、厄尔尼诺/南方涛动指数，以及北大西洋涛动指数。