Scattering phase functions and particle sizes in noctilucent clouds

• Published in: Geophysical research letters Vol. 28; no. 8; pp. 1415 - 1418
• Main Authors: Gumbel, J., Stegman, J., Murtagh, D. P., Witt, G.
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 15.04.2001
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2000GL012414

The MIDAS‐DROPPS campaign conducted in Norway in 1999 provided a comprehensive study of the high‐latitude summer mesopause region with rocket‐borne and ground‐based instrumentation. Optical photometers were flown on two rocket payloads through substantially different mesospheric conditions. On both flights, distinct noctilucent cloud (NLC) layers were detected. We present the first analysis of NLC scattering phase functions observed from sounding rockets. Applying Mie calculations, the angular dependence of the scattering is used to extract information about particle sizes. The first flight featured a weak NLC with small particles (r ≤ 20 nm) located below the core of a strong polar mesosphere radar echo (PMSE). The second flight took place in the absence of any detectable PMSE and probed a bright NLC optically dominated by particles in the size range 40–50 nm.