"The Monsoon Ocean Isn't One-Dimensional: Fronts, Filaments, and Mixing in the Northern Indian Ocean"

Wednesday, September 09, 2026 at 12:30pm to 1:30pm

SMAST East 101-103 : 836 S. Rodney French Boulevard, New Bedford MA 02744
Callie Rumbut
c.rumbut@umassd.edu
https://umassd.zoom.us/j/97440069270

Seminar Announcement

Department of Estuarine and Ocean Sciences

"​The Monsoon Ocean Isn't One-Dimensional: Fronts, Filaments, and Mixing in the Northern Indian Ocean"
Amit Tandon
Professor, Estuarine and Ocean Sciences, SMAST

Wednesday, September 9, 2026
12:30 - 1:30 pm
SMAST E 101-103 and via Zoom

Abstract:

The South Asian monsoon, a coupled ocean-atmosphere feature of the Northern Indian Ocean (Bay of Bengal and Arabian Sea), is one of Earth's great heat engines. Its upper ocean is a natural laboratory for how small-scale physics shapes large-scale weather patterns. Strong river-driven freshwater input, very thin mixed layers, and the twice-yearly wind reversal combine to make this a region where mixing, submesoscale fronts, and air-sea interaction all matter, and where a one-dimensional view of the ocean breaks down. These processes are not well represented in our weather prediction models. This introduces errors in the South Asian monsoon predictions, which degrade forecasts globally on a 7-to-10-day timescale. Improving intraseasonal forecasts globally requires a focused multi-national scientific effort.

This talk traces more than a decade of collaborative field programs in these two basins, including ASIRI-OMM, MISO-BoB, and the ongoing EKAMSAT, spanning ship, mooring, glider, and autonomous-platform observations through to the models they inform. I will show how freshwater sets the stratification and suppresses mixing, how fronts and filaments restratify the upper ocean at rates comparable to air-sea fluxes, and why these processes bias the sea surface temperature and mixed-layer depth that monsoon forecasts depend on. I will close with current work in my lab, including eddy transport of heat and salt, near-inertial waves at curved fronts and shielded eddies, evaluation of reanalysis products and ocean models, and the Aurelia profiling vehicle, together with where we are headed next.

Join Meeting
https://umassd.zoom.us/j/97440069270

Note: Meeting ID and passcode required, email contact to obtain.

For additional information, please contact Callie Rumbut at c.rumbut@umassd.edu