Introduction to the circulation around the Kerguelen Plateau
Owing to its large meridional extent (~18° in latitude) and relatively shallow depths, the Kerguelen Plateau constitutes a major barrier to the eastward flowing Antarctic Circumpolar Current (ACC) in the Indian sector of the Southern Ocean (Figure 1). Previous work showed that most (~100 Sv, 1 Sv = 106 m3 s-1) of the ACC transport is deflected north of the Kerguelen Islands (Park et al., 1993), which implies that a substantial remainder (~50 Sv) has to cross the plateau through two deep passages: the Fawn Trough (56°S, 2650 m) in the middle part, and the Princess Elizabeth Trough (64°S, 3650 m) close to Antarctica. Using two hydrographic WOCE sections (I8 and I9), McCartney and Donohue (2007) suggested a transport of about 40 Sv across the Fawn Trough. Yet, this estimation was only indirect, because the two WOCE sections did not cross optimally the Fawn Trough and Princess Elisabeth Trough areas. These authors also suggested a powerful Australian-Antarctic cyclonic gyre with an unprecedented transport (~100 Sv) in this basin, while the traditional view barely mentions the possibility of such a subpolar gyre. This gyre is associated with a powerful western boundary current strongly concentrated along the eastern flank of the southern Kerguelen Plateau.
Like to PDF article :
The Fawn Trough : a major pathway for the Antarctic circulpolar current across the Kerguelen Plateau - Roquet & al. 4.32 MB