This study examines various dynamical and thermodynamical processes that characterize the Madden– Julian oscillation (MJO). Episodes of deep convection related to the MJO based on rainfall data from the Tropical Rainfall Measuring Mission (TRMM) satellite and the Global Precipitation Climatology Project (GPCP) are identified. Although broad convective envelopes are located utilizing spectrally ...

8 [1] The Madden-Julian Oscillation (MJO), the primary 9 mode of large-scale intraseasonal variability in the tropics, 10 is known to relate to the mid-latitude atmospheric 11 variability. Using neural network techniques, a nonlinear 12 projection of the MJO onto the precipitation and 200-hPa 13 wind anomalies in the northeast Pacific during January– 14 March shows asymmetric atmospheric patter...

In the Indo-Pacific region, mesoscale convective systems (MCSs) occur in a pattern consistent with the eastward propagation of the large-scale convective envelope of the Madden–Julian oscillation (MJO). MCSs are major contributors to the total precipitation. Over the open ocean they tend to be merged or connected systems, while over the Maritime Continent area they tend to be separated or discr...

The modulation of tropical cyclone activity by the Madden–Julian oscillation (MJO) is explored using an empirical genesis potential (GP) index. Composite anomalies of the genesis index associated with the different MJO phases are consistent with the composite anomalies in TC genesis frequency that occur in the same phases, indicating that the index captures the changes in the environment that a...

In Part I of this study it was shown that air–sea coupling had a positive impact on some aspects of the simulation of the Madden–Julian oscillation (MJO) by a GCM. However, errors in the basic-state climate of that GCM appeared to be preventing the MJO-related convection from propagating into the west Pacific. In this paper, the actual impact of these errors will be addressed. An integration of...

27 28 Previous studies have demonstrated a link between gross moist stability (GMS) and intraseasonal 29 variability in theoretical and reduced-complexity models. In such simplified models, moisture modes— 30 convectively coupled tropical disturbances akin to the MJO whose formation and dynamics are linked to 31 moisture perturbations—develop only when GMS is either negative or " effectively " ...

The Madden–Julian oscillation (MJO) is the dominant mode of intraseasonal variability in the tropics. Despite its primary importance, a generally accepted theory that accounts for fundamental features of the MJO, including its propagation speed, planetary horizontal scale, multiscale features, and quadrupole structures, remains elusive. In this study, the authors use a shallow-water model to si...

The interaction between high-frequency transient disturbances and convection, and the Madden–Julian Oscillation (MJO), is investigated using NCEP–NCAR reanalysis and satellite outgoing longwave radiation data for 15 northern winters. During the phase of the MJO with enhanced convection over the East Indian Ocean and Indonesia, and suppressed convection over the South Pacific convergence zone, b...

[1] The Madden‐Julian Oscillation (MJO) is the dominant mode of intraseasonal variability in the tropical atmosphere. This study examines the evolution of the hydrologic regime from before the onset of the MJO (pre‐onset period) to the MJO onset period, using deuterated water vapor (HDO) measurements from the Tropospheric Emission Spectrometer (TES) and from ground‐based stations. Ground‐based ...

The Madden-Julian oscillation (MJO) is the dominant mode of variability in the tropical atmosphere on intraseasonal timescales and planetary spatial scales. Despite the primary importance of the MJO and the decades of research progress since its original discovery, a generally accepted theory for its essential mechanisms has remained elusive. Here, we present a minimal dynamical model for the M...