The Influence of the Stratospheric Quasi‐Biennial Oscillation on the Tropical Easterly Jet Over the Maritime Continent

Abstract

The tropical easterly jet (TEJ) has a strong easterly wind center in the upper troposphere over the Indian Ocean in boreal summer. The maximum wind speed of the Indian Ocean TEJ can reach more than 20 m/s (Huang et al., 2020). TEJ results from the thermal contrast between the Asian continent and the ocean and is enhanced by the local thermal effect of the Tibetan Plateau (Koteswaram, 1958). The large-scale tropical divergent circulations also contribute to the maintenance of TEJ (Chen & van Loon, 1987; Krishnamurti, 1971). TEJ is an important component of the Asian monsoon system (Krishnamurti & Bhalme, 1976) and has an essential effect on the weather and climate in the region influenced by the monsoon; for example, the high-cloud amount in the Asian monsoon region (Sathiyamoorthy et al., 2004), the Tropical Cyclonic Systems in the Bay of Bengal (B. R. S. Rao et al., 2004), Indian summer monsoon rainfall (Huang et al., 2021), summer rainfall of eastern Africa (Vashisht et al., 2021). The Maritime Continent is the entrance of the Indian Ocean TEJ. The TEJ intensity over the Maritime Continent and tropical cyclone genesis frequency over the Western North Pacific have a positive relationship (Zhan et al., 2022). The TEJ is located in the upper troposphere and can extend to 70 hPa at the bottom of the stratosphere (Huang et al., 2020). Previous studies have focused on the influence from the troposphere on TEJ

A Strengthened Teleconnection of the Quasi‐Biennial Oscillation and Tropical Easterly Jet in the Past Decades in E3SMv1

“…The first part discusses the performance of E3SMv1 in simulating the teleconnection between the TEJ and the QBO. According to Li et al (2022), a statistically significant response of the TEJ to the QBO phases at 50 hPa emerged after the 1980s in the observation. Thus, the analysis period in the first part covers 1980 to 2014 to compare the simulations with observations.…”

“…Li et al. (2022) found the TEJ over the Maritime Continent (MC) in the boreal summer is weakened during the easterly QBO (EQBO) and strengthened during the westerly QBO (WQBO). An interesting feature is that the correlation between the QBO and TEJ is stronger in recent decades than before the 1980s (Li et al., 2022), which can be described as a strengthened QBO‐TEJ teleconnection.…”

Effect of quasi‐biennial oscillation on the intensity of the South China Sea summer monsoon

“…Some previous studies presented that Indian summer monsoon circulation is strengthened in late summer in the westerly phase of QBO (Claud & Terray, 2007; Rai & Dimri, 2017). Li et al (2022) proposed that the relationship between QBO and the tropical easterly jet over the Indian Ocean has emerged since the 1980s, and the zonal asymmetries in convection, stability and Kelvin waves are possible causes for the modulation of QBO on the tropical easterly jet.…”

The Key Role of the Vertical Structure of the Stratospheric Quasi‐Biennial Oscillation in the Variations of Asian Precipitation in Summer

“…Accurately predicting summer precipitation in these regions is a pressing need for their social development. Previous studies show that summer precipitation in these regions is influenced not only by tropospheric circulations such as the subtropical westerly jet (SWJ), the South Asian High (SAH), and the Western Pacific Subtropical High (WPSH) (Liao et al., 2004; Wei et al., 2014; Xu et al., 2020), but also by some stratospheric processes, like QBO (Bansod et al., 2000; Li et al., 2022; Madhu, 2014).…”

“…QBO is a prominent interannual signal in the tropical stratosphere, manifested as the zonal‐mean zonal winds alternate between easterlies and westerlies with a period of approximately 24–32 months (Baldwin et al., 2001; Hitchman et al., 2021). It plays an important role in stratosphere‐troposphere coupling (Anstey et al., 2022; Butchart, 2022; Haynes et al., 2021; Hitchman et al., 2021; Kidston et al., 2015; Li et al., 2023; Mundhenk et al., 2018; Tian et al., 2023; Wang et al., 2022). Previous research has found that the QBO could affect deep convection and precipitation in tropical regions (Anstey et al., 2022; Collimore et al., 2003; García‐Franco et al., 2022; Haynes et al., 2021; Huangfu et al., 2021; Nie & Sobel, 2015).…”