Article
Meteorology & Atmospheric Sciences
Changhao Lu, Xuyang Ge, Melinda Peng, Tim Li
Summary: This study investigates the modulation of the decaying pace of El Nino on tropical cyclone activities at low latitudes in the western North Pacific. It found that during slowly decaying El Nino events, there is a higher frequency of tropical cyclones genesis in the southeast of WNP and they tend to form more eastward. The differences in environmental conditions between rapidly and slowly decaying El Nino events play a crucial role in the modulation of tropical cyclone activities in the region.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Ken-Chung Ko, Chi-Cherng Hong, Jyun-Hong Liu
Summary: The study found that the wave pattern was stronger in EP El Nino events, while the monsoon trough was deeper in CP El Nino events. The formation of a stronger subtropical high in CP El Nino events strengthened the southeasterly flow, causing TCs to detour towards Japan. Barotropic conversion and advection played key roles in supporting kinetic energy during the different types of El Nino events.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Jinjie Song, Philip J. Klotzbach, Na Wei, Yihong Duan
Summary: This study investigates the interannual variability of rapid intensification (RI) magnitude of western North Pacific tropical cyclones and finds a significant correlation with the Western Pacific teleconnection index. RI magnitude is larger during positive WP phases and exhibits a southwest-northeast dipolar pattern.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Mei Liang, Jianjun Xu, Johnny C. L. Chan, Chunlei Liu, Hua Xu
Summary: Previous studies have shown that equatorial Pacific Ocean warming can be separated into spring and summer modes based on the onset time of El Nino events, which in turn influences tropical cyclone activity. Different onset times lead to different changes in TC formation location and intensity in the Western North Pacific, with spring mode showing significant eastward and equatorward shifts, particularly in intense TCs, and summer mode only showing an eastward shift. The onset time of El Nino events is suggested as a forecasting indicator for TC genesis position and intensity over the WNP.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Environmental Sciences
Jinjie Song, Philip J. Klotzbach, Yifei Dai, Yihong Duan
Summary: This study investigates the modulation of rapid intensification of tropical cyclones in the western North Pacific by the Antarctic Oscillation. The Antarctic Oscillation has a significant influence on the occurrence of rapid intensification, with positive phases suppressing intensification in the main region and slightly enhancing it in the South China Sea, while negative phases have the opposite effect. This modulation is primarily attributed to changes in dynamic factors, such as vertical wind shear, low-level vorticity, and upper-level divergence, which are influenced by anomalous anticyclones and cyclones triggered by the Antarctic Oscillation.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Cong Guan, Feng Tian, Michael J. McPhaden, Shijian Hu, Fan Wang
Summary: Salinity anomalies in the central Pacific induce the strongest surface warming during both types of El Nino, tapering off to the east and west. The distinct sea surface salinity zonal structures between the two El Ninos amplify their difference in sea surface temperature magnitude by about 10%. Salinity effects on vertical mixing and entrainment account for the different eastern Pacific and central Pacific El Nino responses.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Zhuolin Xuan, Wenjun Zhang, Feng Jiang, Malte F. F. Stuecker, Fei-Fei Jin
Summary: Westerly wind bursts (WWBs) are aperiodic burst-like atmospheric disturbances in the tropics, which play a crucial role in the development of El Nino-Southern Oscillation (ENSO) events and are strongly affected by ENSO itself. Previous studies have shown a pronounced seasonality of WWBs at the equator during El Nino evolution, with more frequent and intense activity in the developing autumn compared to the decaying spring. This study reveals that the seasonal difference in WWB activity is a result of the meridional migration of WWBs, linked to the southward displacement of El Nino-related deep convection. The findings provide a more comprehensive understanding of the spatiotemporal characteristics of WWBs during El Nino events and their relationship with ENSO and atmospheric variability.
Article
Meteorology & Atmospheric Sciences
Yi-Peng Guo, Zhe-Min Tan
Summary: This study found that different types of ENSO events have limited impact on the RI of WNP TCs, mostly affecting the location where RI occurs. During La Nina events, the RI occurrence position shifts northwards, while during EP El Nino and La Nina events, the RI occurrence positions shift westwards in the late TC season.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Environmental Sciences
Xiangbai Wu, Xiao-Hai Yan, Yan Li, Huan Mei, Yuei-An Liou, Gen Li
Summary: This study proposed a new index, the lifetime maximum intensification rates (LMIR), to analyze the dependence of intensification rates of tropical cyclones (TCs) on the variation of environmental conditions. The results showed that the Pacific Decadal Oscillation (PDO) modulates the inter-annual relationship between the LMIR and El Nino/Southern Oscillation (ENSO). Additionally, it was found that different PDO phases have different effects on the intensification of TCs, with warm PDO phase affecting upper ocean heat content and cold PDO phase influencing zonal wind and vertical wind shear.
Article
Meteorology & Atmospheric Sciences
Qiuyun Wang, Jianping Li
Summary: The study reveals that tropical cyclones in the western North Pacific have a clear feedback on El Nino diversity, with accumulated cyclone energy playing a key role in influencing the development of both the eastern-Pacific and central-Pacific El Nino events. Other factors such as sea surface temperature anomalies and zonal wind anomalies also have minor impacts on the process. Additionally, the increased occurrence of central-Pacific El Nino events after 1999/2000 may be linked to weaker accumulated cyclone energy during that period.
Article
Meteorology & Atmospheric Sciences
Jinjie Song, Philip J. Klotzbach, Yihong Duan
Summary: Research shows that there is a significant inverse correlation between the number of tropical cyclones over the western North Pacific during spring and concurrent El Nino-Southern Oscillation conditions. This relationship differs from the weak correlation between TC frequency and ENSO previously documented.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
B. O. Tong, X. I. N. Wang, D. O. N. G. X. I. A. O. Wang, W. E. N. Zhou
Summary: This study proposes a new mechanism for the generation of extreme El Ni iota o events by analyzing interactions between tropical cyclones (TCs) in the western North Pacific (WNP) and sea surface warming in the eastern tropical Pacific. The study finds that anomalously strong TCs in the WNP in spring and summer are essential for the formation of extreme El Ni iota o events. The TCs in spring excite westward wind bursts (WWBs) and facilitate the generation of El Ni iota o events, while the TC activities in summer contribute to the warm sea surface temperature anomalies in the eastern tropical Pacific, leading to extreme El Ni iota o events in the following autumn and winter. These findings are supported by atmosphere-ocean coupled model experiments.
JOURNAL OF CLIMATE
(2023)
Article
Engineering, Marine
Qi Yu, Xianwei Wang, Yongjun Fang, Yazhou Ning, Peiqing Yuan, Bingrou Xi, Runzhi Wang
Summary: This study conducted a comprehensive investigation on the spatiotemporal variations in tropical cyclone activities in the Western North Pacific. The results showed a drastic decrease in cyclone genesis and occurrence frequencies as well as a westward shift in their locations. The study also found significant declines in cyclone frequencies in the South China Sea, southern Philippine Sea, and central Pacific Ocean.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Environmental Sciences
Jinjie Song, Philip J. Klotzbach, Yifei Dai, Yihong Duan
Summary: This study examines the impact of the North Pacific Gyre Oscillation (NPGO) on the rapid intensification (RI) of tropical cyclones in the western North Pacific. The results show a strong negative correlation between basinwide RI numbers and the NPGO index from 1970 to 2021. During the positive phase of NPGO, RI is suppressed throughout the western North Pacific, with different spatial patterns compared to the Pacific Decadal Oscillation. Enhanced negative low-level vorticity is the primary factor leading to reduced RI occurrence over the eastern Philippine Sea, while weak changes in RI occurrence are observed over the western Philippine Sea due to offsetting influences of mid-level humidity and low-level vorticity.
ENVIRONMENTAL RESEARCH COMMUNICATIONS
(2023)
Article
Meteorology & Atmospheric Sciences
Yumeng Li, Ruifen Zhan, Jiuwei Zhao
Summary: Both the years 1998 and 2010 had record-low tropical cyclone (TC) genesis frequency over the western North Pacific (WNP) during the transition from El Nino to La Nina. However, there were significant differences in the rapid intensification (RI) magnitudes of TCs between the two years. The extreme warming and unstable atmosphere in 1998 provided favorable conditions for high RI magnitude, while the extremely decreased low-level relative vorticity led to very low RI magnitude in 2010.
ATMOSPHERIC RESEARCH
(2023)
