Inter-hemispheric differences in PMSE: are they due to differences in mesopause temperatures?

Abstract

Recent observations using the Peruvian\U.S. Profiler at Machu Picchu Base in Antarctica show that PMSE are vastly weaker in the southern hemisphere relative to the north. The difference in average echo strength in the two hemispheres is of the order 23-33 dB. Since the PMSE occurrence is closely associated with the extremely low temperatures that are a well-know feature of the high-latitude summer mesopause region, the most obvious explanation for this discrepancy is that the mesopause temperatures are wanner in the southem hemisphere than they are in the north.