Potential Predictability of the Tropical Cyclone Frequency Over the Western North Pacific With 50‐km AGCM Ensemble Experiments
Potential Predictability of the Tropical Cyclone Frequency Over the Western North Pacific With 50‐km AGCM Ensemble Experiments
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通过 50 公里 AGCM 集合实验对西北太平洋热带气旋频率的潜在可预测性
DOI：
10.1029/2020jd034206
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Nonaka Masami
中科院分区：
文献类型：
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作者：
Ogata Tomomichi;Taguchi Bunmei;Yamamoto Ayako;Nonaka Masami
利用50公里分辨率大气环流模式(AGCM)的集合模拟，研究了热带气旋(TCS)频率分布由海表面温度(SST)决定的潜在可预报性。在这次试验中，西北太平洋(WNP)TC频率的年际变化主要由SST决定，因为模拟的集合平均信号在集合扩散上占主导地位，并有效地跟随6-7-8月观测到的TC频率(JJA)。相反，在9-10-11月(SON)，观测到的TC频率变率与模拟的TC频率变率之间的相关性不显著。为了探讨热带气旋频率与海温的联系，研究了西北太平洋热带气旋频率变率与由海温指数决定的气候模式之间的关系。通过相关分析，我们发现厄尔尼诺·莫多基是热带气旋频率变化的主要驱动因素。偏相关分析进一步表明，大气内部动力对SON的热带气旋频率变率有重要影响。这些结果表明，热带气候模式对西北太平洋热带气旋频率变率的季节可预报性有一定的作用，预报技巧与季节相关，JJA(SON)预报技巧较高(低)。
The potential predictability determined by sea surface temperature (SST) of the frequency distribution of tropical cyclones (TCs) is studied using ensemble simulations with a 50‐km resolution atmospheric general circulation model (AGCM). In this experiment, the interannual variability of the TC frequency over the western North Pacific (WNP) is primarily determined by SST, as the simulated ensemble mean signal is dominant over the ensemble spread and effectively follows the observed TC frequency in June‐July‐August (JJA). In contrast, the correlation between the observed and simulated TC frequency variability is less significant in September‐October‐November (SON). To explore the TC frequency‐SST linkage, the relationship between the TC frequency variability over the WNP and climate modes determined by SST indices is investigated. Through a correlation analysis, we found that El Niño Modoki is the major driver of the TC frequency variability over the WNP in JJA. Partial correlation analysis further reveals that internal atmospheric dynamics are important for the TC frequency variability over the WNP in SON. These results suggest that the tropical climate mode is responsible for the seasonal predictability of the TC frequency variability over the WNP and that the prediction skill is seasonally dependent with a high (low) skill in JJA (SON).