Open AccessOn the dynamics of an observed thermal front off central eastern Australia
Author(s) -
Oke Peter R.,
England Matthew H.,
Middleton Jason H.
Publication year - 2003
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2002jc001370
Subject(s) - advection , front (military) , geology , mooring , shore , current meter , cold front , jet (fluid) , oceanography , climatology , thermal , meteorology , mechanics , physics , thermodynamics
Results from a short observational program off central eastern Australia (28.4°S) are presented. A series of events involving sharp temperature fluctuations and strong pulses in the alongshore currents are measured by a mooring array over the inner shelf. With use of AVHRR images, ADCP, and CTD surveys, it is reasoned that these events correspond to the periodic advection of a thermal front past the inshore moorings. The front involves a temperature change of 1°–2°C, with a southward jet of greater than 0.5 m s −1 over a width of 1–2 km in 25 m of water. The dynamical balances of the momentum equations are examined. It is demonstrated that at the onset of each event the local tendency of alongshore velocity is balanced by across‐shore advection. Additionally, a quasi‐balance between the surface and bottom stress terms is noted throughout the experiment demonstrating the prominence of mixing over the inner shelf.