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...

Abstract: Anewmodel is derived and analyzed for tropical–extratropical interactions involving theMadden– Julian oscillation (MJO). The model combines (i) the tropical dynamics of the MJO and equatorial baroclinic waves and (ii) the dynamics of barotropic Rossbywaves with signi cant extratropical structure, and the combined system has a conserved energy. The method of multiscale asymptotics is a...

The recently developed maximum entropy production (MEP) model, an alternative parameterization of surface heat fluxes, is incorporated into the Weather Research and Forecasting (WRF) model. A pair of WRF cloud-resolving experiments (5 km grids) using the bulk transfer model (WRF default) and the MEP model of surface heat fluxes are performed to hindcast the October Madden-Julian oscillation (MJ...

This study investigates: (i) how the local meridional (Hadley) and zonal (Walker) circulations change in each phase of Madden-Julian Oscillation (MJO); (ii) effect enhanced suppressed MJO-related convection on poleward extent Hadley and, thus, strengths positions subtropical jets. We examine these effects ERA-Interim reanalysis by decomposing vertical mass flux into components. show for first t...

Abstract The Madden‐Julian Oscillation (MJO), the dominant mode of tropical intraseasonal variability, is commonly identified using realtime multivariate MJO (RMM) index based on joint empirical orthogonal function (EOF) analysis near‐equatorial upper and lower level zonal winds outgoing longwave radiation. Here, in place conventional EOFs, we apply an operator‐theoretic formalism dynamic syste...

the madden julian oscillation (mjo) is known as the primary mode of large-scale inter-seasonal variability in tropical regions that affects equatorial and extra-tropical climates. it was characterized as a 45-60 day wave that develops over the tropical indian ocean and then travels east across the tropics at 5-10 m/s. the phenomenon has a frequency of 6-12 events per year associated with a peri...

The Tibetan Plateau (TP), known as the third pole of the Earth, has snow cover with intraseasonal to decadal variability that affects weather and climate both inside and outside the TP. However, the factors that generate the TP snow cover (TPSC) anomalies at the intraseasonal time-scale are unclear. This report reveals the influence of the Madden‒Julian oscillation (MJO), which is the most domi...

The influence of the Madden–Julian oscillation (MJO) on precipitation over Tibetan Plateau (TP) during boreal summer is investigated using observational and reanalysis data 1980–2020. results show that most areas eastern TP increases (decreases) in MJO Phases 1–2 (5–6), especially when eastward-propagating active convection located Indian Ocean (Western Pacific) Phase 2 (6). significant negativ...

The connections between the Madden–Julian Oscillation (MJO) and Arctic (AO) are examined in both observations model forecasts. In observations, time-lag composites carried out for AO indices anomalies of 1,000-hPa geopotential height after an active or inactive initial MJO. results show that when is its positive (negative) phase at time, activity generally enhanced (weakened) Reforecast data 11...

The simulation of the Madden–Julian Oscillation (MJO) and convectively coupled equatorial waves (CCEWs) is considered in 13 state-of-the-art models from phase 6 Coupled Model Intercomparison Project (CMIP6). We use frequency–wavenumber power spectra observations for Outgoing Longwave Radiation (OLR) zonal winds at 250 hPa (U250), consider historical simulations end twenty-first century projecti...