SPREADING OF ANTARCTIC BOTTOM WATER IN THE ATLANTIC OCEAN

Eugene Morozov,Walter Zenk,Roman Tarakanov

doi:10.24057/2071-9388-2012-5-4-24-32

Abstract

This paper describes the transport of bottom water from its source region in the Weddell Sea through the abyssal channels of the Atlantic Ocean. The research brings together the recent observations and historical data. A strong flow of Antarctic Bottom Water through the Vema Channel is analyzed. The mean speed of the flow is 30 cm/s. A temperature increase was found in the deep Vema Channel, which has been observed for 30 years already. The flow of bottom water in the northern part of the Brazil Basin splits. Part of the water flows through the Romanche and Chain fracture zones. The other part flows to the North American Basin. Part of the latter flow propagates through the Vema Fracture Zone into the Northeast Atlantic. The properties of bottom water in the Kane Gap and Discovery Gap are also analyzed.

Highlights

Antarctic Bottom Water (AABW) is formed over the Antarctic slope as a result of mixing of the cold and heavy Antarctic Shelf Water with the lighter, warmer, and more saline Circumpolar Deep Water [Orsi et al, 1999]
The other part flows through the Equatorial Channel, propagating further to the Northeast Atlantic through the Vema Fracture Zone and to the North American Basin in the west, where it is entrained into the cyclonic gyre within its northward spreading zone, reaching the Newfoundland Bank
We summarized the characteristics of the transport of bottom water from its source region in the Weddell Sea through the main abyssal channels of the Atlantic Ocean

Summary

Introduction

Antarctic Bottom Water (AABW) is formed over the Antarctic slope as a result of mixing of the cold and heavy Antarctic Shelf Water with the lighter, warmer, and more saline Circumpolar Deep Water [Orsi et al, 1999]. There are several channels for the flow of Antarctic Bottom Water from the Weddell Sea. It propagates to the north through the passages in the South Scotia Ridge, through the South Sandwich Trench, and South Sandwich Abyssal Plain. A part of the flow is transported to the eastern basin through the Romanche and Chain fracture zones, influencing the waters of the bottom layer in the Southeast Atlantic.

Results

Conclusion