How do MJOs interact with slower climate processes like ENSO?
MJOs may play a role in the transition to an El Nino or La Nina.This means they help determine details of the timing and/or amplitude of a warming or cooling event. However, the transitional stage of an ENSO event is complicated and the MJO’s role is still being investigated. MJOs were prominent during the 1996-97 northern winter at the early stage of the 1997-98 El Nino and this led to heightened awareness of a possible MJO-ENSO link.The 1996-97 MJO activity was by some measures the greatest in the ~30 year record of outgoing longwave radiation (OLR, a proxy for deep tropical convection). On the other hand, 1997-98 had the weakest activity in the record.The two years are contrasted here using a time-longitude or Hovmoller diagram of total OLR for 1996-97 and 1997-98 1996-97 OLR1997-98 OLR Once SST anomalies associated with an ENSO are in place, the MJO life cycle is influenced by the SST anomalies. When or if an MJO develops, the simplest effect during El Nino is a farther eastward mo
