Wind Speed and Surface Fluxes from CYGNSS and Their Role in MJO Dynamics

Prior work has suggested that wind-induced surface flux anomalies strongly regulate the propagation and maintenance of the Madden-Julian oscillation (MJO). However, satellite retrievals of surface wind speed previously used to study such processes may be biased in regions of precipitation, and buoy retrievals have limited spatial sampling. Here, we use wind speed and latent heat flux retrievals from the Cyclone Global Navigation Satellite System (CYGNSS) constellation to assess the importance of wind speed and wind-induced flux variations for destabilization and propagation of the MJO. An object-based tracking algorithm for the MJO and its boreal summer counterpart based on Singh and Kinter (2019) is used as a compositing basis. It is shown that wind-induced fluxes slow the propagation of the MJO, and contribute to its destabilization. A comparison with results derived from OAFlux fields, buoy-derived estimates, and other satellite products is conducted to place current results in a broader context.