We propose simplified metrics to evaluate the fidelity with which the Madden–Julian oscillation (MJO) is simulated in climate models. These metrics are based on lag correlation analysis of principal component time series (PCs). The PCs are obtained by projecting simulated 20–100 day bandpass filtered daily outgoing longwave radiation onto the two leading empirical orthogonal functions of observ...

[1] The effect of the Madden-Julian Oscillation (MJO) on the Northern Hemisphere wintertime stratospheric polar vortex and major, mid-winter stratospheric sudden warmings (SSWs) is evaluated using a meteorological reanalysis dataset. The MJO influences the region in the tropospheric North Pacific sector that is most strongly associated with a SSW. Consistent with this, SSWs in the reanalysis re...

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...

The Madden-Julian oscillation (MJO, Madden and Julian, 1971, 1972) is a dominant feature of intraseasonal (20-90 day) variability in the tropics. According to the classic view, the MJO begins as a positive convective anomaly in the equatorial western Indian Ocean. It then propagates eastward toward the maritime continent where convection weakens until the MJO reaches the west Pacific where the ...

[1] Variability of the cloud population in the central equatorial Indian Ocean was observed in the context of the Madden-Julian Oscillation (MJO) during the Dynamics of the MaddenJulian Oscillation (DYNAMO) and Atmospheric Radiation Measurement Madden-Julian Investigation Experiment (AMIE) field campaigns. Radar observations from the polarimetric S-band radar on Addu Atoll in theMaldives charac...

The Madden–Julian oscillation (MJO) influences tropical cyclone formation around the globe. Convectively coupled Kelvin waves are often embedded within the MJO, but their role in tropical cyclogenesis remains uncertain. This case study identifies the influences of the MJO and a series of Kelvin waves on the formation of two tropical cyclones. Typhoons Rammasun and Chataan developed in the weste...

[1] The vertical distribution of radiative heating affects the moist static energy budget and potentially the maintenance and propagation of the Madden‐Julian Oscillation (MJO). This paper usesCloudSat data to examine the radiative heating climatology in the tropics and the vertical structure of its modulation by the MJO and convectively coupled Kelvin Waves (KWs). Composites of active regions ...

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...

The long-term goal of this project is to understand the role of the atmosphere-ocean interaction processes in the initiation, maintenance and propagation of Madden Julian Oscillation (MJO). Better grasp of the atmosphere/ocean feedbacks in the Tropics will allow formulating more accurate parameterizations of the air-sea interface in the forecasting models. It will contribute to improved predict...