Anomalous winter hydroxyl temperatures at 69°S during 2002 in a multiyear context

Hydroxyl airglow temperatures measured over Davis station, Antarctica (68°S, 78°E) in 2002 are compared to an 8-year climatological mean. The 2002 winter average temperature was 5.1 ± 0.8K warmer than the climatological mean. This anomaly is a factor of two larger than what can be attributed to solar flux increases. Of the 210 nightly averages obtained, 72 (34%) exceeded the climatological maximum, primarily in two unusually warm intervals in late-May to early-June and in mid-July. An unusually cold interval (10 nights below the climatological minimum) coincided with a climatological dip in mid-August. Temperature oscillations of 15–20 K amplitude, extending over 4 cycles across the Sep–Oct stratospheric warming correlate with Rothera temperatures and Davis mesospheric winds and are consistent with a 14-day westward propagating zonal planetary wave number 1.