Cracking the MJO nut

Abstract

[1] The Madden-Julian oscillation poses great challenges to our understanding and prediction of tropical convection and the large-scale circulation. Several internationally coordinated activities were recently formed to meet the challenges from the perspectives of numerical simulations, prediction, diagnostics, and virtual and actual field campaigns. This article provides a brief description of these activities and their connections, with the motivation in part to encourage the next generation of physical scientists to help solve the grand challenging problem of the Madden-Julian oscillation.

Validity of parameter optimization in improving MJO simulation and prediction using the sub-seasonal to seasonal forecast model of Beijing Climate Center

“…The multi-model ensemble results can further increase MJO prediction skill by about 1 week, as shown by the Intraseasonal Variability Hindcast Experiment (ISVHE) Project . Even with the above-mentioned gratifying progress, MJO prediction is still considerably challenging due to its significant sensitivity to initial conditions (e.g., Vitart et al 2007;Fu et al 2011;Liu et al 2017), air-sea coupling (e.g., Vitart et al 2007;Fu et al 2013), differences among models (e.g., Fu et al 2013;Zhang et al 2013;Neena et al 2014), and the characteristics of MJO event itself (e.g., Lin et al 2008a;Rashid et al 2011).…”

Climate SPHINX: evaluating the impact of resolution and stochastic physics parameterisations in the EC-Earth global climate model

“…It is characterised by a strong interaction between tropical convection and the large-scale environment, manifest as a coherent eastward propagating pattern of precipita- tion followed by subsequent rainfall suppression (Khouider et al, 2011;Zhang et al, 2013;Kim et al, 2014;Raymond et al, 2015). It is a challenge for the current generation of global climate and weather models to represent the dynamics and thermodynamics of the MJO realistically (Slingo et al, 1996;Lin et al, 2006;Kim et al, 2009;Sperber et al, 2011;Klingaman et al, 2015).…”

“…The lack of propagation of the MJO over the Maritime Continent into the western Pacific region is a known problem in GCMs (Zhang et al, 2013). An improvement in the MJO propagation past the Maritime Continent due to SPPT has also been seen in the ECMWF seasonal forecasting system 4 (Weisheimer et al, 2014).…”

Multiple and spin off initiation of atmospheric convectively coupled Kelvin waves

“…CCKWs, together with other equatorial eastward and westward propagating perturbations, form the "building blocks" of the multi-scale structure in the active phase of the Madden-Julian Oscillations (MJO) (Majda and Khouider 2004;Mapes et al 2006). The MJO itself is a leading mode of intraseasonal variability in the tropical atmosphere (Lau and Waliser 2011;Madden and Julian 1972;Zhang 2005) with numerous global implications for various components of the weather systems (Zhang 2005;Zhang et al 2013).…”