近日，美国普渡大学Danyang Wang团队揭示了在相对较高的海面温度下，热带气旋扩张得更快。这一研究成果发表在2025年9月15日出版的《美国科学院院刊》杂志上。

预计热带气旋会随着气候变暖而加速增强，但研究热带气旋是否也会随着气候变暖而加速扩张的工作相对较少。最近的理论预测，峰值膨胀率应该随着海表温度（SST）的增加而增加，而物理论据表明，这种依赖性应具体取决于相对SST，即SST与热带平均值的差异。

研究组用历史观测数据检验了这一假设，其中SST变化主要是相对SST的变化。平均膨胀率和峰值膨胀率随着北半球相对海温（27.2 km/d/K和37.5 km/d/K）的增加而系统增加。再分析和最佳跟踪观测数据集的结果都是一致的。均匀海温水行星模拟表明，最大膨胀率对绝对海温的依赖性较弱，表明主要依赖于相对海温。因此，预计平均全球变暖不会强烈改变风暴大小的动态，但海面变暖的模式可能在决定未来风暴大小以及沿海风险如何变化方面发挥重要作用。这项工作还可以帮助改进对风场及其危害和登陆影响的预测。

附：英文原文

Title: Tropical cyclones expand faster at warmer relative sea surface temperature

Author: Wang, Danyang, Chavas, Daniel R., Schenkel, Benjamin A.

Issue&Volume: 2025-9-15

Abstract: Tropical cyclones are expected to intensify more rapidly with warming, but relatively little work has examined whether they could expand more rapidly with warming, too. Recent theory predicts that peak expansion rate should increase with sea surface temperature (SST), and physical arguments suggest this dependence should be specifically on the relative SST, i.e. the SST difference from the tropical mean. We test this hypothesis with historical observational data, in which SST variations are primarily variations in relative SST. Both average and peak expansion rates are found to systematically increase with relative SST globally across the Northern Hemisphere (27.2 and 37.5 km/d/K) and within each individual basin. Results are robust across both reanalysis and Best Track observational datasets. Uniform-SST aquaplanet simulations show a much weaker dependence of maximum expansion rate on absolute SST, suggesting that the dominant dependence is on relative SST. Hence, mean global warming is not expected to strongly change storm size dynamics, but patterns of sea surface warming may play an important role in determining how storm size, and hence coastal risk, may change in the future. This work can also help improve forecasting of the wind field and its hazards and impacts at landfall.

DOI: 10.1073/pnas.2424385122

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2424385122