The southern cold temperate zone

Abstract

The fall of surface temperature towards the south across the southern ocean is not as uniform as it usually appears in mean annual or seasonal temperature charts. In about 40° S it falls rather sharply from 16 to 12 °C in summer or from 12 to 8 °C in winter, and some 10° farther south there is another abrupt fall from about 5 to 3 °C in summer and 3 to 1 °C in winter. The two lines are shown on a circumpolar chart in figure 3. Along the outer line water from the subtropical regions meets colder water from the south, and the contrast is usually greatest where the Brazil, Agulhas and East Australian currents carry warm water southwards. Along the inner line the mixture of water from north and south meets cold water more or less straight from the Antarctic.