2016 Volume 12 Pages 60-64
The eastward propagation processes of the Madden-Julian oscillation (MJO) was examined from a case study of the first MJO generated in late October during CINDY2011. The eastward propagation of the MJO was found to be synchronized with an extratropical cyclone in the Southern Hemisphere. The synchronized propagation of the MJO and the extratrpical cyclone was associated with the ridge and trough pair meridionally extending between 30°S∼15°N. The convection center of the MJO shifted eastward as a result of the westerly winds in the tropics, expanding eastward by the zonal pressure gradient force between the ridge and trough.