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 ...

The effect of the Madden-Julian Oscillation (MJO) on the Northern Hemisphere wintertime stratospheric polar vortex in the period preceding stratospheric sudden warmings is evaluated in operational subseasonal forecasting models. Reforecasts which simulate stronger MJO-related convection in the Tropical West Pacific also simulate enhanced heat flux in the lowermost stratosphere and a more realis...

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 ...

The Madden-Julian Oscillation (MJO) is the dominant component of tropical intraseasonal variability, and a theory explaining its structure and successful numerical simulation remains a major challenge. A successful model for the MJO should have a propagation speed of 4-7 m/s predicted by theory; a wavenumber-2 or -3 structure for the planetary-scale, low-frequency envelope with distinct active ...

In this study we investigated the influence of sea surface temperature (SST) and Madden-Julian Oscillation (MJO) on the organization, strength, and distribution of Mesoscale Convective Systems (MCSs) over the Indo-Pacific region for understanding El Nino Southern Oscillation (ENSO). The study is based on the Tropical Rainfall Measuring Mission’s (TRMM) precipitation features dataset during bore...

The processes that lead to changes in the propagation and maintenance of the Madden-Julian Oscillation (MJO) as a response to increasing CO2 are examined by analyzing moist static energy budget of the MJO in a series of NASA GISS model simulations. It is found changes in MJO propagation is dominated by several key processes. Horizontal moisture advection, a key process for MJO propagation, is f...

Atmospheric rivers (ARs) account for a large portion of winter precipitation in the western US. To evaluate sources AR and predictability at subseasonal-to-seasonal timescales, we examine relationships between two climate modes, El Niño/Southern Oscillation (ENSO) Madden-Julian oscillation (MJO), hydroclimate Our analysis uses ensemble Weather Research Forecast (WRF) model simulations from 1981...