Premium
Influence of multiple sills upon internal wave generation and the implications for mixing
Author(s) -
Xing Jiuxing,
Davies Alan M.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl038181
Subject(s) - sill , mixing (physics) , geology , barotropic fluid , internal tide , internal wave , cascade , oceanography , physics , petrology , chemistry , quantum mechanics , chromatography
A cross sectional non‐hydrostatic model of a fjord is used to examine to what extent the internal tide is modified by two closely spaced sills. The model is forced with an M 2 barotropic tide and internal tides, unsteady lee waves and a jet are generated at the sills. In contrast to an isolated sill, calculations with two closely spaced sills show that the presence of the second sill leads to standing internal wave generation with associated changes in wave spectrum and Richardson number in the inter sill region. Associated with these there is a cascade of energy towards short waves leading to enhanced mixing between the sills. This increase in mixing is consistent with enhanced mixing between closely spaced sills found in observations. It is also relevant to enhanced oceanic mixing and suggest that future mixing measurements should focus on these regions.