Physical Oceanography Laboratory/CIMST, Ocean University of China and Qingdao National Laboratory for Marine Science and Technology, Yushan Road, Qingdao, 266003, China.
Centre for Southern Hemisphere Oceans Research (CSHOR), CSIRO Oceans and Atmosphere, Hobart, TAS, 7004, Australia.
Nat Commun. 2018 Apr 12;9(1):1419. doi: 10.1038/s41467-018-03789-6.
Extreme positive Indian Ocean Dipole (pIOD) affects weather, agriculture, ecosystems, and public health worldwide, particularly when exacerbated by an extreme El Niño. The Paris Agreement aims to limit warming below 2 °C and ideally below 1.5 °C in global mean temperature (GMT), but how extreme pIOD will respond to this target is unclear. Here we show that the frequency increases linearly as the warming proceeds, and doubles at 1.5 °C warming from the pre-industrial level (statistically significant above the 90% confidence level), underscored by a strong intermodel agreement with 11 out of 13 models producing an increase. However, in sharp contrast to a continuous increase in extreme El Niño frequency long after GMT stabilisation, the extreme pIOD frequency peaks as the GMT stabilises. The contrasting response corresponds to a 50% reduction in frequency of an extreme El Niño preceded by an extreme pIOD from that projected under a business-as-usual scenario.
极端正印度洋偶极子（pIOD）影响着全球的天气、农业、生态系统和公共卫生，尤其是当其与极端厄尔尼诺现象同时发生时影响更为严重。《巴黎协定》旨在将全球平均气温（GMT）的升温幅度限制在 2°C 以下，理想情况下限制在 1.5°C 以下，但目前还不清楚极端 pIOD 将如何对此目标做出反应。我们的研究表明，随着变暖的推进，频率呈线性增加，在工业化前水平变暖 1.5°C 时翻了一番（在 90%置信水平以上具有统计学意义），这得到了 13 个模型中的 11 个模型的强烈共识，这些模型都预测到了频率的增加。然而，与 GMT 稳定后厄尔尼诺现象的极端频率持续增加形成鲜明对比的是，极端 pIOD 的频率在 GMT 稳定时达到峰值。这种相反的响应对应于极端厄尔尼诺现象的频率在极端 pIOD 之后减少了 50%，而这一减少是在假设按照现状继续发展的情景下预测的。
