Introduction

• Published in: Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1964
• Subjects: Antarctic; The Antarctic; Indian; Antarc*; Iceberg*
• Online Access: http://dx.doi.org/10.1098/rspa.1964.0163; https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1964.0163

The topic of this afternoon’s Discussion was proposed by a joint panel of the National Committees on Antarctic and Oceanic Research to see whether joint discussion of an outstanding problem would initiate further collaboration. The Antarctic Convergence is a fairly obvious partition round the southern half of the circumpolar ocean, marking where the cold water of the Antarctic surface layer comes up against warmer Subantarctic water. It is always found in more or less the same position and many authors have referred to it as an important climatological and zoogeographical boundary. The physical processes which give rise to it may have a bearing on events in the atmosphere as well as on the general circulation of the ocean. It is not a barrier, the Antarctic water sinks, mixes and continues to the north at a lower level; icebergs get across it, and animals too, but it is an interesting and significant frontier. It should have been rather easy in a country like ours, traditionally interested in the Antarctic and the oceans, to find speakers, but the little we know about the Antarctic Convergence tends to emphasize the lack of really precise information such as scientists like to have, and as convener of the discussion I ought to mention that today’s speakers are not very willing volunteers. The story begins with the report of the meteorological observations of the German South Polar Expedition of 1901–02, published, like most large reports of expeditions, some 20 years later. Professor W. Meinardus, studying the surface temperature observations in the Indian Antarctic sector, found that the decrease of temperature towards the south becomes noticeably slower south of 50° S. The contrast was sufficient to divide the west wind drift into a cold zone to the south and a warm one to the north. He recognized the boundary as a line along which the cold Antarctic water sinks below the warmer Snbantarctic water with a consequent rise in surface temperature towards the north of about 2 °C. Using the observations of other ...