Polar mesosphere summer echo detection using a dynasonde

We describe a new polar mesosphere summer echo (PMSE) radar system implementation that uses a snow-buried antenna operated with the dynasonde at Halley, Antarctica (76°S), the highest southern latitude at which any PMSE measurements have been made to date. Two 100 m2 coaxial-collinear antenna arrays were built so that the antenna beams were colocated at 85 km altitude. Operations in PMSE mode began on 20 January 2004, close to the maximum operational frequency of the system at 28 MHz. PMSE signals were observed at the end of the Antarctic summer season in 2004 and subsequently during the austral summer of 2004/2005 at similar altitudes to PMSE observed in the Northern Hemisphere. We compare the sensitivity of the system to the well-known mesosphere-stratosphere-troposphere radar at Poker Flat (65°N, 147°W, 50 MHz) and calculate a volume reflectivity at 28 MHz of η = 2.9 × 10−11 m−1, which is consistent with that determined from Northern Hemisphere radar systems operating at higher frequencies.

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