Open AccessScale-Dependent Dispersion within the Stratified Interior on the Shelf of Northern Monterey Bay
Author(s) -
Ryan J. Moniz,
Derek A. Fong,
C. Brock Woodson,
Susan K. Willis,
Mark T. Stacey,
Stephen G. Monismith
Publication year - 2014
Publication title -
journal of physical oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.706
H-Index - 143
eISSN - 1520-0485
pISSN - 0022-3670
DOI - 10.1175/jpo-d-12-0229.1
Subject(s) - plume , dispersion (optics) , geology , turbulence , bay , stratified flow , mechanics , oceanography , meteorology , optics , physics
Autonomous underwater vehicle measurements are used to quantify lateral dispersion of a continuously released Rhodamine WT dye plume within the stratified interior of shelf waters in northern Monterey Bay, California. The along-shelf evolution of the plume’s cross-shelf (lateral) width provides evidence for scale-dependent dispersion following the 4/3 law, as previously observed in both surface and bottom layers. The lateral dispersion coefficient is observed to grow to 0.5 m2 s−1 at a distance of 700 m downstream of the dye source. The role of shear and associated intermittent turbulent mixing within the stratified interior is investigated as a driving mechanism for lateral dispersion. Using measurements of time-varying temperature and horizontal velocities, both an analytical shear-flow dispersion model and a particle-tracking model generate estimates of the lateral dispersion that agree with the field-measured 4/3 law of dispersion, without explicit appeal to any assumed turbulence structure.