On the roles of the northeast cold surge, the Borneo vortex, the Madden--Julian Oscillation, and the Indian Ocean Dipole during the extreme 2006//2007 flood in southern Peninsular Malaysia
Fredolin T. Tangang,1 Liew Juneng,1 Ester Salimun,1 P. N. Vinayachandran,2 Yap Kok Seng,3
C. J. C. Reason,4 S. K. Behera,5 and T. Yasunari6
Received 27 January 2008; revised 18 March 2008; accepted 16 April 2008; published 31 May 2008
The mid-December 2006 to late January 2007 flood in southern Peninsular Malaysia was the worst flood in a century and was caused by three extreme precipitation episodes. These extreme precipitation events were mainly associated with strong northeasterly winds over the South China Sea. In all cases, the northeasterlies penetrated anomalously far south and followed almost a straight trajectory. The elevated terrain over Sumatra and southern Peninsular Malaysia caused low-level convergence. The strong easterly winds near Java associated with the Rossby wave-type response to Madden-Julian Oscillation (MJO) inhibited the counter-clockwise turning of the northeasterlies and the formation of the Borneo vortex, which, in turn, enhanced the low-level convergence over the region. The abrupt termination of the Indian Ocean Dipole (IOD) in December 2006 played a secondary role as warmer equatorial Indian Ocean helped in the MJO formation. Citation: Tangang, F. T., L. Juneng, E. Salimun, P. N. Vinayachandran, Y. K. Seng, C. J. C. Reason, S. K. Behera, and T. Yasunari (2008), On the roles of the northeast cold surge, the Borneo vortex, the Madden-Julian Oscillation, and the Indian Ocean Dipole during the extreme 2006/2007 flood in southern Peninsular Malaysia,
Geophys. Res. Lett., 35, L14S07,doi:10.1029/2008GL033429.
