A mechanism denial study on the Madden‐Julian Oscillation

摘要: [1] A series of Madden-Julian oscillation (MJO) mechanism-denial experiments is performed using an atmospheric general circulation model (AGCM). Daily climatological seasonal cycles i) surface latent heat flux, ii) net radiative heating rate, and iii) wind stress are obtained from a control simulation prescribed in place the normal interactive computations these fields order to turn off wind-induced exchange (WISHE), cloud-radiation interaction (CRI), frictional wave-CISK (FWC) mechanisms, respectively. Dual triple mechanism denial also conducted by switching multiple mechanisms together. The influence each assessed comparing with that turned those which it not. CRI WISHE both found be important simulated MJO amplitude propagation speed, while FWC has weaker less systematic effects. weakened when off, but strengthened indicating amplifies weakens it. negative shown result phase relationships between winds, fluxes convection differ significantly observations, thus not interpreted as evidence against positive role for development maintenance observed MJO. consistent strong relationship daily grid-point column-integrated convective heating; mean ratio latter former exceeds 0.2 rain rates than 14 mm d−1. suppress excessive excitation convectively coupled Kelvin wave so frequency maintained.