A Train-Like Extreme Multiple Tropical Cyclogenesis Event in the Northwest Pacific in 2004
A Train-Like Extreme Multiple Tropical Cyclogenesis Event in the Northwest Pacific in 2004
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2004年西北太平洋类似火车的极端多重热带气旋事件
DOI：
10.1029/2018gl078749
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发表时间：
2018-08-28
影响因子：
5.2
通讯作者：
Mei, Wei
中科院分区：
文献类型：
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作者：
Hu, Kaiming;Chan, Johnny C. L.;Mei, Wei
利用观测数据集，确定了西北太平洋上前所未有的多重热带气旋生成事件，2004年8月6日至9月10日期间有7个热带气旋相继形成。在这次事件中，先前存在的热带气旋（TC）通过激发Rossby波在其尾流区产生交替的气旋和反气旋扰动。气旋扰动随后在季风槽内增强为新的热带气旋，热带中太平洋的异常变暖和热带印度洋的冷却可能增强了热带气旋扰动，因此它持续的时间足以让七个热带气旋连续发展。对1979-2014年历史记录的分析证实了这种极端多热带气旋生成事件的发生与异常海表温度模式和季风槽的联系。热带气旋（Tropical cyclones，TC）是一种严重的天气现象，对区域和全球气候有重要的调节作用。TC引发的极端事件往往会给人类社会带来巨大的灾难。这项研究确定了一个迄今未报告的极端事件，七个热带气旋聚集在西北太平洋在2004年夏末。在有记录的多个热带气旋生成事件（MTCEs）中，该事件中的TC数量最多。研究表明，2004年夏季热带中太平洋的异常变暖和热带印度洋的异常变冷是造成这次极端MTCE的部分原因。历史记录进一步证实，异常的海面温度模式增加了发生MTCE的可能性。该结果对提高极端MTCE的预测能力具有重要意义。
Using observed data sets, an unprecedented multiple tropical cyclogenesis event over the northwest Pacific is identified, with seven tropical cyclones forming in sequence from 6 August to 10 September 2004. In this event, the preexisting tropical cyclones (TCs) generated the alternating cyclonic and anticyclonic disturbances in their wake region by exciting Rossby waves. The cyclonic disturbances subsequently intensified into new TCs within the monsoon trough, which was likely enhanced by anomalous warming in the tropical central Pacific and cooling in the tropical Indian Ocean, so that it lasted long enough to allow seven TCs to develop consecutively. An analysis of the historical records during 1979-2014 substantiates such linkage of the occurrence of this extreme multiple tropical cyclogenesis event to the anomalous sea surface temperature pattern and the monsoon trough. This result has important implications regarding the prediction of the multiple cyclogenesis events.Plain Language Summary Tropical cyclones (TCs) are severe weather phenomenon, with important role in modulating regional and global climate. TC-induced extreme events often bring huge disasters to human society. This study has identified a hitherto unreported extreme event that seven TCs clustered together over the northwest Pacific in the late summer of 2004. The number of TCs in this event is the highest among the recorded multiple tropical cyclogenesis events (MTCEs). This study shows that the occurrence of this extreme MTCE is partly caused by the anomalous warming in the tropical central Pacific and cooling in the tropical Indian Ocean in the summer of 2004. Historical record further confirms that the anomalous sea surface temperature pattern increases the possibility in the occurrence of MTCEs. The result has important implications to improve the prediction skill of extreme MTCEs.