RECENT VARIATIONS IN MEAN TEMPERATURE AND THE DIURNAL TEMPERATURE-RANGE IN THE ANTARCTIC

Monthly mean surface temperature data are available from nearly twenty stations for the period since the international Geophysical Year 1957 . All but three stations show an increase in mean temperatures over th is time, amounting in the average to 0.57 degrees C over 1957 to 1994. All of this warming occurred before the early 1970s. Since then, ther e has been no change. The warming has been greatest in the Antarctic P eninsula. Analyses of the less-widely available diurnal temperature ra nge (DTR) (maximum-minimum) data show regions of increase and decrease over Antarctica, An average continental DTR series shows no trend ove r 1957 to 1992. Analyses for six mid-to-high latitude Southern Ocean i slands show increases in mean temperature over 1961-90. Given the low year-to-year variability in these data, these trends are more signific ant than for any of the stations on the Antarctic continent. The marke d decrease in mean temperatures over Antarctica during 1993 and 1994 s eems unrelated to sea-ice variations which show little change since th e early 1980s.