The Madden-Julian Oscillation (MJO) is the dominant component of the intraseasonal (30–90 days) variability in the tropical atmosphere. It consists of large-scale coupled patterns in atmospheric circulation and deep convection, with coherent signals in many other variables, all propagating eastward slowly ( 5 m s ) through the portion of the Indian and Pacific oceans where the sea surface i...
JANUARY 2003 AMERICAN METEOROLOGICAL SOCIETY | S ince its discovery by Madden and Julian (1971, 1972) over two decades ago, the Madden–Julian oscillation (MJO) has continued to be a topic of significant interest due to its complex nature (Madden and Julian 1994) and the wide range of phenomena with which it interacts. The onset and break activity of the Asian–Australian monsoon system is strong...
Basinwide convective anomalies over the IndianOcean (IO) associated with theMadden–Julian oscillation (MJO) sometimes propagate eastward and reach the west Pacific (WP), but sometimes do not. Long-term observations and reanalysis products are used to investigate the difference between the propagating and nonpropagating MJO events. IO convection onset events associated with the MJO are grouped i...
Moisture mode instability is thought to occur in the tropical oceanic atmosphere when precipitation is a strongly increasing function of saturation fraction (precipitable water divided by saturated precipitable water) and when convection acts to increase the saturation fraction. A highly simpli ed model of the interaction between convection and large-scale ows in the tropics suggests that there...
This paper presents a new empirical model to simulate the Madden–Julian oscillation (MJO), which is the most prominent mode of tropical intraseasonal variability. Zonal wind components at 850 and 200 hPa from reanalysis (1948–2007) and outgoing longwave radiation from satellites (1979–2007) are used to identify MJOs and characterize their statistical properties. The temporal variability of the ...
Matthew C. Wheeler,
Aline de H. N. Maia,
Roger C. Stone,
The accuracy of synoptic-based weather forecasting deteriorates rapidly after five days and is not routinely available beyond 10 days. Conversely, climate forecasts are generally not feasible for periods of less than 3 months, resulting in a weather-climate gap. The tropical atmospheric phenomenon known as the Madden-Julian Oscillation (MJO) has a return interval of 30 to 80 days that might par...
The large-scale equatorial circulation known as the Madden–Julian oscillation (MJO) has been shown to impact tropical cyclone activity in several basins around the globe. In this paper, the author utilizes an MJO index created by Wheeler and Hendon to examine its impacts on tropical genesis and intensification in the Atlantic. Large differences in frequency and intensity of tropical cyclone act...
Gavin A. Schmidt,
 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 ...
Duane E. Waliser,
Ralph A. Kahn,
Yuk L. Yung,
Igor V. Geogdzhayev,
Michael I. Mishchenko,
 We investigate the modulation of aerosols by the Madden-Julian Oscillation (MJO) using multiple, global satellite aerosol products: aerosol index (AI) from the Total Ozone Mapping Spectrometer (TOMS) on Nimbus-7, and aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Advanced Very High Resolution Radiometer (AVHRR) on NOA...
The Madden–Julian oscillation (MJO) is an equatorial planetary-scale circulation system coupled with a multiscale convective complex, and it moves eastward slowly (about 5 m s) with a horizontal quadrupole vortex and vertical rearward-tilted structure. The nature and role of scale interaction (SI) is one of the elusive aspects of the MJO dynamics. Here a prototype theoretical model is formulate...