Detection of a 40–50 Day Oscillation in the Zonal Wind in the Tropical Pacific

Madden, Roland A.; Julian, Paul

doi:10.1175/1520-0469(1971)028<0702:doadoi>2.0.co;2

Cited by 2,814 publications

(1,436 citation statements)

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“…Madden-Julian oscillation (MJO; Madden and Julian 1971) is a well-known phenomenon that prevails in the tropics and exerts remarkable modulations on the tropical and extratropical atmospheric circulations. Due to its close connection with a wide range of local or remote weather and climate events (e.g., tropical cyclone, mid-latitude weathers, monsoon, and El Niño-Southern Oscillation), MJO has become an important topic of many research and operational centers.…”

Section: Introductionmentioning

confidence: 99%

Validity of parameter optimization in improving MJO simulation and prediction using the sub-seasonal to seasonal forecast model of Beijing Climate Center

Liu

et al. 2018

Clim Dyn

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Using the sub-seasonal to seasonal forecast model of Beijing Climate Center, several key physical parameters are perturbed by the Latin hypercube sampling method to find a better configuration for representation of Madden-Julian oscillation (MJO) in the free-run simulation. We find that although model simulation is especially sensitive to some parameters, there are overall no significant linear relationships between model skill and any one of the parameters, and the optimum performance can be obtained by combined perturbations of multiple parameters. By optimization, MJO's spectrum, intensity, spatial structure and propagation, as well as the mean state and variance, are all improved to some extent, suggesting the correspondence and interrelation of model's performances in simulating different characteristics of MJO. Further, several sets of initialized hindcasts using the optimized parameters are conducted, and their results are compared with the hindcasts using only improved initial conditions. We show that with an optimized model, the forecast of MJO beyond 3-week lead time is not improved, and the maximum useful skill is only slightly increased, implying that a decrease of model error does not always translate into an increase of forecast skill at all lead time. However, the skill is obviously enhanced during lead times of 2-3 weeks for forecasts in most seasons and initial phases except for a few cases. Particularly, the deficiency in forecasting MJO's propagation from the Indian Ocean to the Pacific is relieved, further highlighting the positive contribution of reducing model error compared to previous work that only reduced initial condition error. In this study, we also show benefits of multi-scheme ensemble strategy in describing uncertainties of model error and initial condition error and thus improving MJO forecast.

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Section: Introductionmentioning

confidence: 99%

Validity of parameter optimization in improving MJO simulation and prediction using the sub-seasonal to seasonal forecast model of Beijing Climate Center

Liu

et al. 2018

Clim Dyn

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“…Meinen and McPhaden (2000) showed that a sufficiently high Pacific warm water volume (WWV; the volume of water warmer than 208C) is relevant for the occurrence of El Niño events because in order to warm the eastern Pacific Ocean (PO), sufficient heat should be present in the western PO, which is then discharged during El Niño. Also, small-scale processes can play a role in ENSO (Kleeman 2008), in particular intraseasonal spells of westerly winds (Keen 1982), such as those provided by the Madden-Julian oscillation (MJO) (Madden and Julian 1971;Zhang 2005). ''Bursts'' of westerly winds over the western PO generate equatorial Kelvin waves, which affect the thermocline in the eastern PO, favoring the development of an El Niño (Kessler et al 1995;McPhaden et al 2006).…”

Section: Introductionmentioning

confidence: 99%

Coherent Tropical Indo-Pacific Interannual Climate Variability

et al. 2016

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A multichannel singular spectrum analysis (MSSA) applied simultaneously to tropical sea surface temperature (SST), zonal wind, and burstiness (zonal wind variability) reveals three significant oscillatory modes. They all show a strong ENSO signal in the eastern Pacific Ocean (PO) but also a substantial SST signal in the western Indian Ocean (IO). A correlation-based analysis shows that the western IO signal contains linearly independent information on ENSO. Of the three Indo-Pacific ENSO modes of the MSSA, one resembles a central Pacific (CP) El Niño, while the others represent eastern Pacific (EP) El Niños, which either start in the central Pacific and grow eastward (EPe) or start near Peru and grow westward (EPw). A composite analysis shows that EPw El Niños are preceded by cooling in the western IO about 15 months earlier. Two mechanisms are discussed by which the western IO might influence ENSO. In the atmospheric bridge mechanism, subsidence over the cool western IO in autumn (year 0) leads to enhanced convection above Indonesia, strengthening easterlies over the western PO, and the creation of a large warm water volume. This is essential for the creation of (EP) El Niños in the following spring-summer. In the state-dependent noise mechanism, a cool western IO favors a strong intraseasonal zonal wind variability over the western PO in early spring (year 1), which can partly be attributed to the Madden-Julian oscillation. This intraseasonal variability induces Kelvin waves, which in early spring lead to a strong warming of the eastern PO and can initiate EPw El Niños.

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“…The dominant component of intraseasonal variability in the tropics is the 40-to-50-day tropical intraseasonal oscillation (ISO), often called the Madden-Julian oscillation (MJO), after its discoverers (Madden and Julian, 1971). The MJO has continued to be a topic of significant interest due to its clear modulation of weather conditions and the wide range of phenomena with which it interacts.…”

Section: Introductionmentioning

confidence: 67%

A Review of the Nonlinear Dynamics of Intraseasonal Oscillations

Zhao

Jian-Zhou

2011

Atmospheric and Oceanic Science Letters

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In recent years, significant progress has been made regarding theories of intraseasonal oscillations (ISOs) (also known as the Madden-Julian oscillation (MJO) in the tropics). This short review introduces the latest advances in ISO theories with an emphasis particularly on theoretical paradigms involving nonlinear dynamics in the following aspects: (1) the basic ideas and limitations of the previous and current theories and hypotheses regarding the MJO, (2) the new multi-scale theory of the MJO based on the intraseasonal planetary equatorial synoptic dynamics (IPESD) framework, and (3) nonlinear dynamics of ISOs in the extratropics based on the resonant triads of Rossby-Haurwitz waves.

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Detection of a 40–50 Day Oscillation in the Zonal Wind in the Tropical Pacific

Cited by 2,814 publications

References 0 publications

Validity of parameter optimization in improving MJO simulation and prediction using the sub-seasonal to seasonal forecast model of Beijing Climate Center

Validity of parameter optimization in improving MJO simulation and prediction using the sub-seasonal to seasonal forecast model of Beijing Climate Center

Coherent Tropical Indo-Pacific Interannual Climate Variability

A Review of the Nonlinear Dynamics of Intraseasonal Oscillations

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