Year-end Sale % OFF 
Abstract
The monsoon circulation in the Northern Indian Ocean (NIO) is unique since it develops in response to the bi-annual reversing monsoonal winds, with the ocean currents mirroring this change through directionality and intensity. The interaction between the reversing currents and topographic features have implications for the development of the Island Mass Effect (IME) in the NIO. The IME in the NIO is characterized by areas of high chlorophyll concentrations identified through remote sensing to be located around the Maldives and Sri Lanka in the NIO. The IME around the Maldives was observed to reverse between the monsoons to downstream of the incoming monsoonal current whilst a recirculation feature known as the Sri Lanka Dome (SLD) developed off the east coast of Sri Lanka during the Southwest Monsoon (SWM). To understand the physical mechanisms underlying this monsoonal variability of the IME, a numerical model based on the Regional Ocean Modeling System (ROMS) was implemented and validated. The model was able to simulate the regional circulation and was used to investigate the three-dimensional structure of the IME around the Maldives and Sri Lanka in terms of its temperature and velocity. Results revealed that downwelling processes were prevalent along the Maldives for both monsoon periods but was applicable only to latitudes above 4°N since that was the extent of the monsoon current influence. For the Maldives, atolls located south of 4°N, were influenced by the equatorial currents. Around Sri Lanka, upwelling processes were responsible for the IME during the SWM but with strong downwelling during the NEM. In addition, there were also regional differences in intra-seasonal variability for these processes. Overall, the strength of the IME processes was closely tied to the monsoon current intensity and was found to reach its peak when the monsoon currents were at the maximum.
Highlights
The Maldives island chain and Sri Lanka occupy a unique location within the Northern Indian Ocean (NIO) at the crossroads of water exchange between the higher salinity Arabian Sea (AS) to the west and the freshwater dominated Bay of Bengal (BoB) to the east (Figure 1)
This paper examined the monsoonal variability of IME processes, such as island wake circulation and upwelling around the Maldives and Sri Lanka
A numerical model based on the ROMS framework was implemented for Sri Lanka and the Maldives in the NIO
Summary
The Maldives island chain and Sri Lanka occupy a unique location within the Northern Indian Ocean (NIO) at the crossroads of water exchange between the higher salinity Arabian Sea (AS) to the west and the freshwater dominated Bay of Bengal (BoB) to the east (Figure 1). During the NEM, the monsoon winds blow from the northeast toward the southwest direction whilst winds during the SWM come from the opposite direction. This directionality is mirrored by the two monsoon currents, the Northeast Monsoon Current (NMC) and the Southwest Monsoon Current (SMC). The NMC flows westwards from the BoB, past Sri Lanka toward the Maldives, bringing lower salinity (less dense) water from the BoB to the AS during the NEM (Figure 1A). The Southwest Monsoon Current (SMC) flows eastwards from the AS, past the northern end of the Maldives toward Sri Lanka, transporting higher salinity (more dense) water from the AS to the BoB (Figure 1A; de Vos et al, 2014b)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
