Understanding where water goes and how fast it gets there sets the stage for everything else: oxygen supply, carbon storage, nutrient delivery, and contaminant fate. I use tracers, floats, gliders, and long-term records to quantify advection and ventilation from the open ocean to coastal estuaries.

Subtropical Mode Water (North Atlantic)

  • Observed a dramatic decline in STMW formation and inventory during the 2010s.
  • Why it matters: weaker mode water reduces upper-ocean heat and carbon storage, and alters mid-latitude ventilation.
  • Project page: Subtropical Mode Water.
Time-series of STMW properties
Time-series of North Atlantic STMW properties at BATS. Stevens et al., 2020

TReX Deep (Gulf of St. Lawrence)

  • Conservative tracer release + floats to measure along-channel transport and dispersion of the deep inflow.
  • At-a-glance: inland advection ~0.5 cm s⁻¹; travel time to estuary head O(1–5) years; boundary mixing influences vertical pathways.
  • Project page: TReX Deep.
Tracer spreading
Tracer and float evolution from the TReX Deep experiment. Communications Earth & Environment (2024)

Intermediate circulation (Salish Sea)

  • Transit times and renewal pathways in the Strait of Georgia set exposure windows for biogeochemistry and contaminants.
  • Project page: Salish Sea.
Transit time in the Strait of Georgia
Transit-time structure for intermediate waters in the Strait of Georgia. Stevens et al., 2021

Papers & reports