Declining tropical cyclone frequency under global warming
Declining tropical cyclone frequency under global warming
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DOI：
10.1038/s41558-022-01388-4
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发表时间：
2022-06-27
影响因子：
30.7
通讯作者：
Murakami, Hiroyuki
中科院分区：
文献类型：
--
作者：
Chand, Savin S.;Walsh, Kevin J. E.;Murakami, Hiroyuki
在存在较大自然变率的情况下，从时间上不均匀的历史数据评估人为变暖的作用是困难的，并且在热带气旋（TC）趋势的探测和归因方面导致了相互矛盾的结论。在此，我们利用一个重建的年总热值的长期代理和高分辨率气候模式试验，显示了20世纪全球和区域尺度上的年总热值的强劲下降趋势。之所以使用20世纪再分析（20CR）数据集进行重建，是因为与其他再分析相比，它只吸收海平面压力场，而不是利用对流层中所有可用的观测数据，使其对观测数据的时间不均匀性不太敏感。它还可以相当好地捕获前卫星时代的TC特征。所发现的下降趋势与20世纪哈德利和沃克环流的减弱相一致，这使得TC形成的条件不太有利。从观测记录中发现热带气旋的变化是困难的。这里使用年度气旋数量再分析数据进行的重建显示，在20世纪，它们在全球和区域范围内都有所下降。
Assessing the role of anthropogenic warming from temporally inhomogeneous historical data in the presence of large natural variability is difficult and has caused conflicting conclusions on detection and attribution of tropical cyclone (TC) trends. Here, using a reconstructed long-term proxy of annual TC numbers together with high-resolution climate model experiments, we show robust declining trends in the annual number of TCs at global and regional scales during the twentieth century. The Twentieth Century Reanalysis (20CR) dataset is used for reconstruction because, compared with other reanalyses, it assimilates only sea-level pressure fields rather than utilize all available observations in the troposphere, making it less sensitive to temporal inhomogeneities in the observations. It can also capture TC signatures from the pre-satellite era reasonably well. The declining trends found are consistent with the twentieth century weakening of the Hadley and Walker circulations, which make conditions for TC formation less favourable.Detecting change in tropical cyclones is difficult from observational records. Here a reconstruction using reanalysis data of annual cyclone numbers shows they have declined globally and regionally over the twentieth century.