Clouds associated with the MJO: A new perspective from CloudSat

This study uses two years (June 2006 – June 2008) of CloudSat data to characterize clouds associated with the Madden Julian Oscillation (MJO). Two approaches are used to define the MJO. The first defines eight MJO phases relative to minima, maxima, and min-slope, max-slope conditions in filtered outgoing longwave radiation (ORL). The second approach also defines eight MJO phases, but this time phases are defined using Wheeler and Hendon's (2004) Real Time Multivariate MJO (RMM) index. In each approach, composites of cloud statistics are made for each phase. Cloud statistics include: identification of cloud types, total cloudiness, anomalous cloud cover, and temperature and moisture profiles per phase. In addition to these bulk statistics, we keep track of individual cloud objects (i.e. echo objects) to construct pictorial realizations of actual (i.e. CloudSat observed) clouds across the MJO. The pictorial realizations are attempts to mimic schematics from previous works (e.g. Madden and Julian 1972, Morita et al. 2006, and Benedict and Randall 2007). The hope of this work is to challenge pre-conceived ideas of cloud structure across the MJO based on new findings from CloudSat.