Influence of Barrier Layer on Sea Surface Height Variability in Bay of Bengal
Kalyani Chikka(1) , K.V Ramesh(1) , and P.S Swathi(1)
NAL Belur Campus, Wind Tunnel Road,
Bangalore 560 037,
Studies have documented that the barrier layer formation may have significant impact on air-sea interactions. The advancements in the ocean in-situ observations, satellite based observations and ocean modelling provides us an opportunity to investigate the influence of barrier layer formation on the SST and heat content variability on seasonal and intrannual time scales. The satellite altimetry has opened a new dimension for monitoring the variability of the Sea Surface Height (SSH) without the assumption of level of no motion. SSH can be used as a proxy to understand the upper ocean heat content variability. Bay of Bengal is typically marked with fresh water flux and heavy rainfall and also convective mixing due to surface cooling cause the fresh water to mix down to the top of thermocline, thus disturbs the barrier layer. Due to the formation of barrier layer we can observe changes in the subsurface temperature and salinity on intraseasonal to seasonal time scales.
Hence we made an attempt to understand importance of barrier layer formation on SST variability. To study these features on various scales we have analysed Topex/Poseidon derived Sea Surface Height (SSH), TMI derived SST and satellite derived precipitation. Along with the above data we have used high resolution OGCM simulations for the years 1997-2004. In this study we have observed that the barrier layer significantly affects SST and the heat flux. These results are validated with few ARGO observations.