Department of Earth System Science, University of California, Irvine, CA 92697.
Proc Natl Acad Sci U S A. 2013 Sep 17;110(38):15207-10. doi: 10.1073/pnas.1306753110. Epub 2013 Aug 6.
Tropical cyclones have been hypothesized to influence climate by pumping heat into the ocean, but a direct measure of this warming effect is still lacking. We quantified cyclone-induced ocean warming by directly monitoring the thermal expansion of water in the wake of cyclones, using satellite-based sea surface height data that provide a unique way of tracking the changes in ocean heat content on seasonal and longer timescales. We find that the long-term effect of cyclones is to warm the ocean at a rate of 0.32 ± 0.15 PW between 1993 and 2009, i.e., ∼23 times more efficiently per unit area than the background equatorial warming, making cyclones potentially important modulators of the climate by affecting heat transport in the ocean-atmosphere system. Furthermore, our analysis reveals that the rate of warming increases with cyclone intensity. This, together with a predicted shift in the distribution of cyclones toward higher intensities as climate warms, suggests the ocean will get even warmer, possibly leading to a positive feedback.
热带气旋被认为通过将热量泵入海洋来影响气候，但这种变暖效应的直接衡量标准仍然缺乏。我们通过直接监测气旋尾流中水体的热膨胀，利用基于卫星的海面高度数据来量化气旋引起的海洋变暖，这些数据提供了一种独特的方法来跟踪海洋热含量在季节和更长时间尺度上的变化。我们发现，在 1993 年至 2009 年期间，气旋的长期影响是使海洋以 0.32 ± 0.15 PW 的速率变暖，即单位面积内每单位面积的变暖效率比背景赤道变暖高约 23 倍，这使得气旋通过影响海洋-大气系统中的热输送而成为影响气候的重要调节因子。此外，我们的分析表明，变暖速率随着气旋强度的增加而增加。这一点，再加上随着气候变暖，气旋分布向更高强度的转变预测，表明海洋将变得更加温暖，可能导致正反馈。
