Skip to main content
eScholarship
Open Access Publications from the University of California

SF6-3He tracer release experiment: A new method of determining longitudinal dispersion coefficients in large rivers

  • Author(s): Clark, JF
  • Schlosser, P
  • Stute, M
  • Simpson, HJ
  • et al.

Published Web Location

https://doi.org/10.1021/es9504606
Abstract

Longitudinal dispersion coefficients have been determined in the tidal Hudson River using sulfur hexafluoride. For this purpose, SF6, a nonreactive synthetic gas, was injected into the Hudson south of Albany, NY, and used in a fashion similar to a fluorescent dye. Three days after injection, SF6 distributions along the main axis of the river were approximately Gaussian. The change in variance with time showed two periods of linear growth. During the first period (days 3-8), the longitudinal dispersion coefficient was estimated to be 47 ± 6 m2 s-1, and during the second period (days 8-13), it was 162 ± 22 m2 s-1. A second gas, 3He, which was injected simultaneously with SF6, allowed for the determination of gas exchange rates across the air-water interface. Gas transfer velocities normalized to a Schmidt number of 600 ranged from 2.8 to 9.2 cm h-1 and correlated well with mean wind speed.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View