On monitoring two major current systems of the north Indian Ocean using an array of deep-sea moorings

• Published in: Journal of Earth System Science 2022-10, Vol.131 (4), p.218, Article 218
• Main Authors: Jain, Vineet, Amol, P, Aparna, S G
• Format: Article
• Language: English
• Subjects: Annual variations; Arrays; Coasts; Current observations; Deep sea; Deep sea environments; Deep sea moorings; Deep water; Earth and Environmental Science; Earth Sciences; Equator; Equatorial currents; Fourier transforms; Heat exchange; Monsoons; Mooring; Mooring systems; Ocean currents; Oceans; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Summer; Summer monsoon; Wind; Winter; Winter monsoon
• ISSN: 0973-774X; 0253-4126; 0973-774X
• DOI: 10.1007/s12040-022-01971-5

The region between the southern tip of the Indian subcontinent and the equator links the Arabian Sea and the Bay of Bengal. A significant exchange of mass, heat and salt occurs in the region via two major current systems: the monsoon current (dominant annual cycle) and the equatorial current (dominant semi-annual cycle). This paper presents observations from deep-sea mooring programmes and describes the rationale for maintaining a mooring array along 77.4 ∘ E to monitor both current systems. Analysis shows that the semi-annual to annual cycle transition occurs at 2–2.5 ∘ N, with the winter monsoon current peaking at 5 ∘ N, the summer monsoon current at 3–6 ∘ N, and the equatorial current at 0–1 ∘ N. Research highlights Ocean current observations are shown in the monsoon and equatorial currents regime at 77.4 ∘ E. The transition between monsoon and equatorial current occurs at 2-2.5 ∘ N. Summer (winter) monsoon current is strongest at 3-6 ∘ N (5 ∘ N). Minor expansion of existing mooring programmes to monitor two major current systems in the North Indian Ocean is proposed.