Review of large scale circulation and convection associated with the MJO and other coherent subseasonal tropical variability during DYNAMO

The DYNAMO [Dynamics of the Madden-Julian Oscillation (MJO)] field campaign is currently ongoing and will continue through March 2012 with the hopes of better understanding the precursors and mechanisms for MJO onset and propagation across the Indian Ocean region. The MJO has been quite active at the start of the field campaign period and already resulted in sampling during one suppressed phase and one enhanced phase of the MJO to date. Additional MJO activity is probable during the remainder of the campaign and this paper will present a review of conditions for convection and circulation over the span of the field campaign in a broad scale context. This will include a description of the MJO activity throughout the campaign and its impact on conditions across the DYNAMO array as well periods when other forms of coherent subseasonal tropical variability such as atmospheric Kelvin waves and equatorial Rossby waves modulated the MJO variability in proximity to the DYNAMO site. Additional noteworthy impacts such as tropical cyclone activity will also be described. Dynamical model forecasts of an MJO index from several international operational centers performed well during the first month of the campaign and a complete review of model forecast performance of these models over the entire campaign period will be presented.