We investigate the connection between the equatorial Madden-Julian Oscillation (MJO) and different types of the Northern Hemisphere mid-winter major stratospheric sudden warmings (SSWs), i.e., vortex-displacement and vortex-split SSWs. The MJO-SSW relationship for vortex-split SSWs is stronger than that for vortex-displacement SSWs, as a result of the stronger and more coherent eastward propaga...

The Madden-Julian oscillation (MJO) has been documented in previous studies to significantly impact tropical cyclone activity in all ocean basins. Most of these studies have utilized the Wheeler-Hendon index. This index is only available since 1974, the period over which remotely sensed outgoing longwave radiation data has been available. Our study utilizes a long reconstructed MJO index, based...

[1] The Madden-Julian Oscillation (MJO) is the primary mode of large-scale intraseasonal variability in the tropics. Recent work has connected the MJO to atmospheric variability in mid-latitudes. We focus on relationships between the MJO and wintertime surface air temperatures in the Northern Hemisphere high latitudes. The MJO is diagnosed using principal EOF of 850 hPa zonal winds from the NCE...

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...

The Madden–Julian oscillation (MJO) is parameterized to study the role of the feedback it receives from sea surface temperature (SST) in its influence on El Niño–Southern Oscillation (ENSO). The parameterization describes MJO surface westerlies in terms of a few basic parameters that include amplitude, zonal propagation extent, propagation speed, and the interval between adjacent events. It is ...

The Madden–Julian oscillation (MJO) is analyzed using the reanalysis zonal wind– and satellite outgoing longwave radiation–based indices of Wheeler and Hendon for the 1974–2005 period. The average lifetime of the MJO events varies with season (36 days for events whose central date occurs in December, and 48 days for events in September). The lifetime of the MJO in the equinoctial seasons (March...

[1] We investigate the intraseasonal (30–90 day) variations in satellite-observed tropical total ozone (O3) and their connection to theMadden-Julian Oscillation (MJO). Tropical total O3 intraseasonal variations are large ( ±10 DU) and comparable to those in annual and interannual time scales. These O3 anomalies are mainly evident in the subtropics over the Pacific and eastern; hemisphere and pr...

The Madden–Julian oscillation (MJO) is known as the dominant mode of tropical intraseasonal variability and has an important role in the coupled-atmosphere system. This study uses numerical model experiments to investigate the influence of the MJO activity on weather predictability in the midlatitudes of the Northern Hemisphere. The National Aeronautics and Space Administration (NASA) Goddard L...