Seasonality and Buoyancy Suppression of Turbulence in the Bay of Bengal

Abstract

A yearlong record from moored current, temperature, conductivity, and four mixing meters (χpods) in the northernmost international waters of the Bay of Bengal quantifies upper‐ocean turbulent diffusivity of heat (Kt) and its response to the Indian monsoon. Data indicate (1) pronounced intermittency in turbulence at semidiurnal, diurnal, and near‐inertial timescales, (2) strong turbulence above 25‐m depth during the SW (summer) and NE (winter) monsoon relative to the transition periods (compare Kt > 10−4 m2/s to Kt ∼ 10−5 m2/s, and (3) persistent suppression of turbulence (Kt −5 m2/s) for 3 to 5 months in the latter half of the SW monsoon coincident with enhanced near‐surface stratification postarrival of low‐salinity water from the Brahmaputra‐Ganga‐Meghna delta and monsoonal precipitation. This suppression promotes maintenance of the low‐salinity surface waters within the interior of the bay preconditioning the upper northern Indian Ocean for the next year's monsoon.

Document Details

Document Type
Pub Defense Publication
Publication Date
Apr 23, 2019
Source ID
10.1029/2018gl081577

Entities

People

  • E. Shroyer
  • J. Thomas Farrar
  • James N. Moum
  • Rama Govindarajan
  • Ritabrata Thakur
  • Robert A. Weller

Organizations

  • Ministry of Earth Sciences
  • Office of Naval Research
  • Oregon State University
  • Tata Institute of Fundamental Research
  • Woods Hole Oceanographic Institution

Tags

Fields of Study

  • Environmental science

Readers

  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers
  • Oceanography.