A large-amplitude mixed Rossby–gravity wave packet is identified in the western Pacific using 6–10-day bandpass-filtered winds. Individual disturbances of 2300–3000-km wavelength propagated westward as the packet moved slowly eastward. The packet first appeared, and subsequently amplified, within a region of active convection associated with the Madden–Julian oscillation (MJO), which was isolat...

Abstract The Madden–Julian oscillation (MJO) is the dominant intraseasonal wave phenomenon influencing extreme weather and climate worldwide. Realistic simulations accurate predictions of MJO genesis are cornerstones for successfully monitoring, forecasting, managing meteorological disasters 3–4 weeks in advance. Nevertheless, processes emerging precursor signals an eastward-propagating event r...

Abstract The predictability limit of the Madden‐Julian Oscillation (MJO) in El Niño and La Niña boreal winters (November‐February) is investigated using observational data historical run outputs CMIP models. MJO computed by nonlinear local Lyapunov exponents approach for various indices obtained from bandpass‐filtered (30–80 days) outgoing longwave radiation, 850‐hPa zonal wind, 200‐hPa wind da...

Possible sources of the observed modulation tropical Madden-Julian oscillation (MJO) by stratospheric quasi-biennial (QBO) and 11-year solar cycle are investigated using 41 years reanalysis data archived climate model data. Larger upward fluxes extratropical planetary-scale waves, leading in some cases to sudden warmings (SSWs), late fall early winter during easterly phase QBO than westerly (th...

A recent article by Vallis and Penn (2020) in this journal presented the behaviour of a simple single-layer model moist dynamics, identifying an “excitable” which feedback between condensational heating gravity waves sustained high values kinetic energy and, when was equatorial β -plane configuration, Madden–Julian Oscillation (MJO)-like disturbance, eastward-propagating including localised reg...

Research has been conducted on the influence of Madden Julian Oscillation (MJO) phenomenon rainfall anomalies in Bali Province since 1991-2020. aims to figure out conditions, anomalies, and frequency distributions during existence MJO’s 4 5 phase for 1991-2020 a descriptive statistical methods. The data used is daily results observations from Jembrana Class II Climatology Station MJO phases whi...

Convective momentum transport (CMT) plays a central role in interactions across multiple space and time scales. However, because of the multiscale nature of CMT, quantifying and parameterizing its effects is often a challenge. Here a simple dynamic model with features of CMT is systematically derived and studied. The model includes interactions between a large-scale zonal mean flow and convecti...

A composite life cycle of the Madden–Julian oscillation (MJO) is constructed using an index based on the first two EOFs of the bandpass-filtered (20–80 days) 850-mb zonal wind averaged from 58N to 58S every 2.58 around the equator. Precipitation, 1000-mb convergence, 850-mb wind, and 200-mb wind are composited for the period 1979–95. Water vapor integrated from the surface to 300 mb is composit...

Abstract The Madden–Julian oscillation (MJO) is often observed to weaken or sometimes completely decay as its convective anomaly moves from the Indian Ocean over Maritime Continent (MC), which known MC barrier effect on MJO. This exaggerated in numerical models. Using 23 years of retrospective intraseasonal forecast two coupled model systems with useful MJO prediction skills, we show that predi...

The circulation associated with convection of the Madden-Julian Oscillation (MJO) has been suggested to have an impact on its propagation by a number previous studies. This contains both flanking Rossby waves rear and Kelvin wave leading convective center. In this study, individual MJO envelopes from 40-year database are tracked, technique scale zonal wavelength is employed, statistical methods...