A comparison of hydroxyl rotational temperatures from Davis (69°S, 78°E) with sodium lidar temperatures from Syowa (69°S, 39°E)

Abstract

[1] We report the first substantive inter‐site comparison of high southern latitude mesopause region winter temperatures. Davis (69°S, 78°E) hydroxyl rotational nightly‐mean temperatures are significantly correlated with Syowa (69°S, 39°E) sodium lidar nightly‐mean temperatures at 87 km made in 2000 (correlation coefficient of 0.68) and 2001 (0.51) despite a site separation of ∼1500 km. The Davis winter average temperature in 2001, 203 K, differs from the Syowa value of 201 K only by the uncertainty in the measurement. A more substantial 7 K separates the year 2000 winter averages, Davis again being warmer. The temperature difference between the sites is attributed to either variations in the hydroxyl layer or short‐term cooling events in the mesopause region above Syowa that are not detected above Davis. Syowa winter temperatures at 87 km are ∼7 K cooler than for an equivalent latitude northern hemisphere site.