The behavior of double-diffusive intrusion in a rotating system

Journal Article · Sat Apr 15 00:00:00 EDT 1989 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JC094iC04p04923· OSTI ID:5877940

Yoshida, J ^[1]; Nagashima, H ^[2]; Niino, H ^[3]

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1. Tokyo Univ. of Fisheries (Japan)
2. Inst. of Physical and Chemical Research, Hirosawa (Japan)
3. Meteorological Research Inst., Tsukuba (Japan)

The effects of Earth's rotation on the stability of a thermohaline front of finite width are studied by means of a linear theory. It is found that when the rotation is present, two different types of unstable modes are possible. When the front is narrow and a Rossby radius of deformation based on Ruddick and Turner's (1979) vertical scale is large in comparison with the width of the front, the fastest growing intrusion is nearly two dimensional (nonrotational mode), and its vertical scale is given by Ruddick and Turner's scale. When the Rossby radius becomes small, in addition to the nonrotational mode there appears another unstable mode (the rotational mode) which has a smaller vertical wave number than the nonrotational mode. With the introduction of rotation, the fastest growing mode has nonzero along-frontal wave number; that is, the intrusion becomes tilted in the along-frontal direction. When the Rossby radius of deformation is sufficiently small in comparison with the width of the front, transition from the nonrotational mode to the rotational one occurs. The transition from nonrotational to rotational mode becomes less pronounced when the width of the front is increased for fixed horizontal density-compensating gradients of temperature and salinity. For a wide front the growth rate and vertical wave number for both modes becomes similar, which agrees with the results of previous studies for infinite fronts that rotation does not modify the behavior of the intrusion except for the occurrence of along-frontal tilt.

• OSTI ID: 5877940
• Journal Information: Journal of Geophysical Research; (United States), Vol. 94:C4; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
EARTH PLANET
ROTATION
SEAS
SALINITY GRADIENTS
TEMPERATURE GRADIENTS
DOWNWELLING
GENERAL CIRCULATION MODELS
OCEANIC CIRCULATION
OCEANOGRAPHY
SEAWATER
THERMAL DIFFUSION
WATER CURRENTS
CURRENTS
DIFFUSION
HYDROGEN COMPOUNDS
MATHEMATICAL MODELS
MOTION
OXYGEN COMPOUNDS
PLANETS
SURFACE WATERS
WATER
580000* - Geosciences