Tidal and spring-neap variations in horizontal dispersion in a partially mixed estuary
MetadataShow full item record
A sequence of dye releases in the Hudson River estuary provide a quantitative assessment of horizontal dispersion in a partially mixed estuary. Dye was released in the bottom boundary layer on 4 separate occasions, with varying tidal phase and spring-neap conditions. The three-dimensional distribution of dye was monitored by two vessels with in situ, profiling fluorometers. The three-dimensional spreading of the dye was estimated by calculating the time derivative of the second moment of the dye in the along-estuary, cross-estuary and vertical directions. The average along-estuary dispersion rate was about 100 m2/s, but maximum rates up to 700 m2/s occurred during ebb tides, and minimum rates occurred during flood. Vertical shear dispersion was the principal mechanism during neap tides, but transverse shear dispersion became more important during springs. Suppression of mixing across the pycnocline limited the vertical extent of the patch in all but the maximum spring-tide conditions, with vertical diffusivities in the pycnocline estimated at 4 × 10−5 m2/s during neaps. The limited vertical extent of the dye patch limited the dispersion of the dye relative to the overall estuarine dispersion rate, which was an order of magnitude greater than that of the dye. This study indicates that the effective dispersion of waterborne material in an estuary depends sensitively on its vertical distribution as well as the phase of the spring-neap cycle.
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C07023, doi:10.1029/2007JC004644.
Showing items related by title, author, creator and subject.
Li, Yizhen; He, Ruoying; Chen, Ke; McGillicuddy, Dennis J. (John Wiley & Sons, 2015-05-19)A data assimilative ocean circulation model is used to hindcast the Gulf of Maine [GOM) circulation in spring and summer 2010. Using the recently developed incremental strong constraint 4D Variational data assimilation ...
Friedland, Kevin D.; Leaf, Robert T.; Kane, Joe; Tommasi, Desiree; Asch, Rebecca G.; Rebuck, Nathan D.; Ji, Rubao; Large, Scott I.; Stock, Charles A.; Saba, Vincent S. (Elsevier, 2015-04-07)The spring phytoplankton bloom on the US Northeast Continental Shelf is a feature of the ecosystem production cycle that varies annually in timing, spatial extent, and magnitude. To quantify this variability, we analyzed ...
Radio LAN acquisition module (RLAM) : recent developments for high resolution data collection systems as implemented for the ONR sea ice mechanics experiment, spring 1994 von der Heydt, Keith; Eck, Calvert F. (Woods Hole Oceanographic Institution, 1995-05)During a recent experiment (April 1994), for the ONR Sea Ice Mechanics Initiative (SIMI), a portable data acquisition system was assembled that included 2 new developments. The first consists of a board, designed for the ...