Numerical Simulation of MJO Genesis: The Impact of the DYNAMO Data

The Madden-Julian Oscillation (MJO) is a planetary-scale development of convection over equatorial tropical atmosphere with a period of 30-90 days. It is challenging to properly simulate and forecast MJO initiation and progression. This study examine the MJO initiation through high-resolution numerical simulation and data assimilation of observations from the field campaign the DYNAmics of the MJO (DYNAMO) and future NASA mission the CYclone Global Navigation Satellite System (CYGNSS).

The DYNAMO has intense observation from the NASA TOGA Doppler radar, a lidar, a wind profiler, near-surface anemometer, and radiosondes during September 2011 through March 2012 in the equatorial Indian Ocean. Using the Weather Research and Forecasting (WRF) model and its 3DVAR data assimilation system, the multi-platform data from the DYNAMO is assimilated for a MJO event in November 2011. The numerical model result will cast light on the meso-scale feature on MJO initiation and development of convection. Preliminary result from the assimilation experiments will be discussed at the conference. Further details of the methodology of data assimilation, the influences of different DYNAMO datasets, and the impact of various dataset on MJO initiation and development will be presented at the conference.

The CYclone Global Navigation Satellite System (CYGNSS) mission is a planned constellation consisting of multiple micro-satellites that leverage the Global Positioning System (GPS) to provide rapidly updated, high-resolution (~15-50 km, ~4 h) surface wind speeds over the tropical oceans. The CYGNSS can provide useful information for MJO development. This presentation will also discuss our recent effort examining the simulated CYGNSS data and explore the potential impact of the CYGNSS data.