A quasi‐biennial oscillation in the intensity of the intra‐seasonal oscillation

Kuma, Ken-ichi

doi:10.1002/joc.3370100304

Cited by 16 publications

(8 citation statements)

References 11 publications

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“…The impact of stratospheric circulation on the MJO has been reported in connection to the QBO (Kuma, 1990;Yoo and Son, 2016). The present results suggest that the change in TTL stability due to anomalous stratospheric downwelling had an impact on the sudden termination of the MJO event in early December 2011 (Fig.…”

Section: Discussion and Concluding Remarkssupporting

confidence: 72%

Stratospheric tropical warming event and its impact on the polar and tropical troposphere

et al. 2017

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Abstract. Stratosphere-troposphere coupling is investigated in relation to middle atmospheric subtropical jet (MASTJ) variations in boreal winter. An exceptional strengthening of the MASTJ occurred in association with a sudden equatorward shift of the stratospheric polar night jet (PNJ) in early December 2011. This abrupt transformation of the MASTJ and PNJ had no apparent relation to the upward propagation of planetary waves from the troposphere. The impact of this stratospheric event penetrated into the troposphere in two regions: in the northern polar region and the tropics. Due to the strong MASTJ, planetary waves at higher latitudes were deflected and trapped in the northern polar region. Trapping of the planetary waves resulted in amplification of zonal wave number 1 component, which appeared in the troposphere as the development of a trough over the Atlantic sector and a ridge over the Eurasian sector. A strong MASTJ also suppressed the equatorward propagation of planetary waves, which resulted in weaker tropical stratospheric upwelling and produced anomalous warming in the tropical stratosphere. In the tropical tropopause layer (TTL), however, sublimation of ice clouds kept the temperature change minor. In the troposphere, an abrupt termination of a Madden-Julian Oscillation (MJO) event occurred following the static stability increase in the TTL. This termination suggests that the stratospheric event affected the convective episode in the troposphere.

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Section: Discussion and Concluding Remarkssupporting

confidence: 72%

Stratospheric tropical warming event and its impact on the polar and tropical troposphere

et al. 2017

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“…Concurrently, Tan (1980, 1982) suggested a similar association between these polar stratospheric warmings and the QBO (see also Wallace and Chang, 1982). The conclusions of recent studies by Kuma (1990), Yasunari (1989), Enfield (1990), , Knaff (1991), Knaff et al, (1992), Gray et al, ( , 1992 and Angell (1992) argue for direct linkage between the stratospheric QBO and various tropospheric and oceanic data series. Van loon and Labitzke (1988), , and Sheaffer (1991) have also presented evidence of active modulation of ENSO-linked teleconnections into mid-latitude areas by the stratospheric QBO.…”

Section: Related Researchmentioning

confidence: 87%

“…The 30-60 day oscillation Kuma (1990) using Singapore (1.4*N latitude) rawinsonde data, observed a QBO-linked variation in the intensity of the 30-60 day oscillation (ISO). This effect was noted to be especially pronounced during the Austral summer (December to March) period.…”

Section: Regional Anomalies In Surface Datamentioning

confidence: 99%

Influence of the Stratospheric QBO on ENSO Variability

Gray

Sheaffer

Knaff

1992

Journal of the Meteorological Society of Japan

104

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A hypothetical mechanism is described whereby the Quasi-Biennial Oscillation (QBO) of Zonal winds in the equatorial stratosphere actively modulates the timing of El Nino-Southern Oscillation (ENSO) events. The mechanism involves the meridional redistribution of deep convective activity throughout the tropical Pacific warm pool region in response to variable wind shear processes which are linked to the opposing phases of the QBO. Hydrostatic conditions favoring deep convective activity within approximately *7* of the equator develop in response to the easterly shear phase of the QBO. At the same time, deep convection is inhibited in the monsoon-convergence zones farther off the equator (8-18* latitude) during the east phase of the QBO. The opposite trends occur during the westerly shear phase of the QBO wherein deep equatorial convection is suppressed while off equator monsoon convection is enhanced. It is shown that during the east phase of the QBO, the Pacific regional pressure and circulation anomalies which arise in response to QBO-linked trends in convective activity are consistent with conditions leading to warm ENSO events (i.e., El Nino). If the heat content of the warm pool is sufficient, a warm event will occur. Conversely, conditions favoring the development of cold (or La Nina) events tend to occur in association with the westerly phase of the QBO. Although several aspects of the hypothetical mechanism remain tentative, extensive empirical results present a compelling argument for the QBO as an active and fundamental component of ENSO variability

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“…A relationship between the QBO and the MJO was first noted by Kuma (1990), who found that the intensity of upper-tropospheric winds associated with the MJO was well correlated with the QBO. Little subsequent work was done until more recent studies, beginning with Yoo and Son (2016), spurred renewed interest in the topic (Yoo and Son 2016;Marshall et al 2017;Son et al 2017;Hood 2017;Nishimoto and Yoden 2017;Lee and Klingaman 2018;Zhang and Zhang 2018;Hendon and Abhik 2018;Wang et al 2018).…”

Section: Introductionmentioning

confidence: 84%

The Impact of the QBO on MJO Convection in Cloud-Resolving Simulations

Martin

Wang

Nie

et al. 2019

Journal of the Atmospheric Sciences

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This study examines the relationship between the Madden–Julian oscillation (MJO) and the stratospheric quasi-biennial oscillation (QBO) in a limited-area cloud-resolving model with parameterized large-scale dynamics. The model is used to simulate two consecutive MJO events that occurred during the late fall and early winter of 2011. To test the influence of the QBO on the simulated MJO events, various QBO states are imposed via the addition of characteristic wind and temperature anomalies. In experiments with only QBO temperature anomalies imposed (without corresponding zonal wind anomalies) the strength of convection during MJO active phases is amplified for the QBO easterly phase [an anomalously cold tropical tropopause layer (TTL)] compared to the westerly QBO phase (a warm TTL), as measured by outgoing longwave radiation, cloud fraction, and large-scale ascent. This response is qualitatively consistent with the observed MJO–QBO relationship. The response of precipitation is weaker, and is less consistent across variations in the simulation configuration. Experiments with only imposed QBO wind anomalies (without corresponding temperature anomalies) show much weaker effects altogether than those with imposed temperature anomalies, suggesting that TTL temperature anomalies are a key pathway through which the QBO can modulate the MJO. Sensitivity tests indicate that the QBO influence on MJO convection depends on both the amplitude and the height of the QBO temperature anomaly: lower-altitude and larger-amplitude temperature anomalies have more pronounced effects on MJO convection.

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A quasi‐biennial oscillation in the intensity of the intra‐seasonal oscillation

Cited by 16 publications

References 11 publications

Stratospheric tropical warming event and its impact on the polar and tropical troposphere

Stratospheric tropical warming event and its impact on the polar and tropical troposphere

Influence of the Stratospheric QBO on ENSO Variability

The Impact of the QBO on MJO Convection in Cloud-Resolving Simulations

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