Drifter observations of monsoon intra-seasonal oscillations in the tropical Indian Ocean and the Bay of Bengal

Abstract

In this study, we propose to deploy 80 Surface Velocity Program (SVP) drifters drogued at 15 m that are designed to follow ocean currents in a Lagrangian sense [Niiler, 2001; Maximenko et al., 2013]. The drifters will be fabricated by the Lagrangian Drifter Laboratory (LDL) at the Scripps Institution of Oceanography (SIO), with ruggedized battery packs to extend the drifter’s lifetime, an Iridium transmitter, and a GPS receiver. The expected lifetime of the drifters, which will measure SST at a depth of 20 cm in the standard configuration, is approximately two years. Since the standard SST sensor and the drogue are located at different depth, some of the drifters will be equipped with an additional (inductive) temperature sensor at the top of the drogue (SVP-2T) to explore this potential source of inaccuracy in the proposed effort (Figure 2). This is particularly important in the presence of surface freshwater lenses that can lead to significant near-surface temperature gradients. The drifters will be registered under the Global Drifter Program (GDP), which in turn will be financially responsible for the satellite transmission costs. In exchange, the drifter data will be made publicly available in real time through the Global Telecommunication System of the World Weather Watch and will therefore be easily accessible in real time by all the major forecast centers including the US Navy. As part of this proposal, no funds are requested for the fabrication of the SVP drifters that will be made available through other ONR funded efforts.

Document Details

Document Type
DoD Grant Award
Publication Date
Sep 30, 2019
Source ID
N000141912691

Entities

People

  • Verena Hormann

Organizations

  • Office of Naval Research
  • United States Navy
  • University of California, San Diego

Tags

Readers

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

Technology Areas

  • Space