Spatial scales of temperature and flow in Drake passage

Journal Article · Sun Jul 20 04:00:00 EDT 1980 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JC085iC07p04015· OSTI ID:5161323

Sciremammano, F Jr; Pillsbury, R D; Nowlin, Jr, W D; Whitworth, T III

An analysis of 3 years of current meter data (1975, 1976, and 1977) from Drake Passage is used to assess the vertical and the horizontal scales of temperature and flow. It is found that temperature and current fluctuations are highly correlated vertically in the mid-depth range. The only exceptions are in the temperature structure in the upper layers (300--500 m) which is complex and not well correlated with that in the deeper layers and a relative increase in current variability at depths near 3000 m, and below. Most of the measurements were near the sourthern edge of the Polar Frontal Zone where it is found that the horizontal scales for temperature fluctuations are approximately equal in the through- and the across passage directions at 100--110 km. If the data from the entire passage is used, this scale is reduced to approximately 80 km. The velocity fluctuations in the through- and the across-passage directions are found to be narrow (of the order of 30--40 km) normal to their flow direction and elongated (55--80 km) parallel to it. These measured spatial scales are shown to be consistent with observations of individual mesoscale disturbances reported from this region of the Antarctic Circumpolar Current. The observed disturbances are generally in the form of meanders or lateral excursions of the narrow current core associated with the polar front or of rings formed from separations of loops of this current. The polar front, and the associated current core, are found to migrate north and southe on a time scale of months. A northward shift of the front during the austral winter is indicated in the records from all 3 years. Although the correlations at large separations (>100 km) were generally small, an analysis of their sign structure indicates a small response is present at scales on the order of half the passage width.

• Research Organization: Oregon State University, Corvallis, Oregon 97331
• OSTI ID: 5161323
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 85:C7; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580500* -- Oceanography-- (1980-1989)
ANTARCTIC REGIONS
CURRENTS
FLOW RATE
FLUCTUATIONS
LAYERS
POLAR REGIONS
SEAS
SEASONAL VARIATIONS
SURFACE WATERS
TEMPERATURE MEASUREMENT
VARIATIONS
WATER CURRENTS