Seasonal variations and inter-year trends in 7 years of hydroxyl airglow rotational temperatures at Davis station (69°S, 78°E), Antarctica

Seasonal variation of hydroxyl rotational-temperatures above Davis, Antarctica (68.6degreesS, 73.0degreesE) is determined from 1148 nightly means collected over 7 years (1990 and 1995-2000). Measurements are limited by sunlight at this latitude to between day-of-year (DOY) 49 and 296. Sharp temperature transitions, particularly in autumn (1.2 K d(-1)), bracket an extended winter maximum with a slow temperature decrease (-0.03 K d(-1) from DOY 85 to 260). Seasonal variability and absolute magnitudes (206+/-4 K for a 1 July average across the years measured) are very similar to measurements at a comparable northern latitude (Lubken and von Zhan, 1991). A solar cycle association of 0.06 K (sfu)(-1) (10.7 cm solar flux unit = 10(-22) W m(-2) Hz(-1)), implying a 7 K variation over a 120 sfu range solar cycle, fits the measured winter temperatures. (C) 2002 Elsevier Science Ltd. All rights reserved.