Combined Effect of the PDO and ENSO on the Date of the First Tropical Cyclone Landfall in Continental East Asia

Abstract

The date of the first tropical cyclone (TC) landfall (DFTCL) is important for TC disaster prevention. This study analyzes the variation in the characteristics of the DFTCL in continental East Asia and investigates the possible effect of the Pacific Decadal Oscillation (PDO) and the El Niño‐Southern Oscillation (ENSO) on the DFTCL. Results show that the combined effect of the PDO and ENSO plays an important role in whether TC landfall occurs relatively earlier or later. During negative PDO phases, the DFTCL is impacted significantly by ENSO events. TCs tend to make landfall later (earlier) in the years following El Niño (La Niña). However, little influence is noticeable for the ENSO events during positive PDO phases. The combined effect is possibly associated with the anomalous anticyclone (cyclone) in the western North Pacific (South China Sea) which is modulated by different PDO phases asymmetrically. During negative PDO phases, the tropical Indian Ocean (TIO) has a strong response to El Niño events in winter. The warm anomaly persists in the following months until early summer. This induces the anomalous anticyclone in the western North Pacific which is enhanced by the anomalous meridional circulation. The anomalous anticyclone can suppress TC genesis and landfall. On the other hand, the TIO has a significant cooling response to La Niña events and induces the anomalous cyclone near the South China Sea. The anomalous cyclone favors earlier than usual TC genesis and landfall. However, this relationship cannot be detected in the positive PDO phase.

PDO-ENSO Effects on Southern Brazilian Precipitation

“…More recently, Nguyen et al (2021) examined the combined effects of ENSO and PDO on global droughts in terms of magnitude, timing, and duration, and Gamelin et al (2020) investigated the role of ENSO on upper troposphere-lower stratosphere ozone variability with a focus on South America by examining patterns of teleconnections in warm and cool PDO phases. Speci c studies discuss the modulating effect of the PDO on ENSO precipitation in other regions of the world (Wang and Liu, 2016, Xue et al, 2018, Zeng et al, 2021, Li et al, 2021. ENSO is the primary coupled mode acting on interannual timescales that modulates tropospheric circulation worldwide.…”