Summary of Abstract Submission

Abstract Submission No. IO50-11-0013PresentationPoster

INTRASEASONAL VARIABILITY OF BAROTROPIC SEA-LEVEL IN THE TROPICAL INDIAN OCEAN

B Rohith*1, Arya Paul1, S.S.C. Shenoi1, Laurent Testut2

1 Indian National Centre for Ocean Information Services (INCOIS), INDIA
2 LEGOS, Toulouse, FRANCE

ABSTRACT :

Sea level data obtained from the bottom pressure recorders (during 2010 2013) in the north Indian Ocean were analysed to examine whether there exists any variability at frequencies other than at tidal frequencies. It was found that the variability at intraseasonal frequencies is significant and the variability intensifies during December-April simultaneously at locations in the southern Bay of Bengal as well as in the Northern Arabian Sea. Using satellite measurement of equivalent water depth and modeling studies revealed that the signal observed at the BPR locations were a part of the basin wide phenomenon rather than a local phenomenon. Experiments using a general circulation model run only with barotropic mode suggested that the winds in the northwestern Australian Basin (AWAB) have caused the variability by propagating a barotropic disturbance at a speed of ~ 125 m s-1. It was also noticed that the sea level in the Southern India Ocean (south of 30 S) behaved out of phase than that in the northern Indian Ocean.