Diurnal variations of midlatitude NLC parameters observed by daylightcapable lidar and their relation to ambient parameters

[1] Noctilucent Clouds (NLCs) are an important phenomenon of the summer mesopause region. While relatively common in high latitudes, NLCs are sparse ( 10% occurrence rate) below 60 latitude. We present the first study of diurnal variations of midlatitude NLCs based on lidar observations with full diurnal coverage at Kühlungsborn since 2010 independent from solar elevation. Overall, 100 h of NLCs with a backscatter coefficient of ˇmax,532nm > 0.5 10–10 m–1sr–1 are observed within 1800 h. Occurrence rates decrease regularly from 12% at 5 local solar time (LST) to 2% at 19 LST. The mean NLC brightness varies between 1 and 3 10–10 m–1sr–1 with maxima at 4 and 18 LST. The simultaneously observed temperatures show a systematic (tidal) variation, but we do not find a direct relation to NLC rates. Comparing NLCs and ambient winds, we find strong indications for the meridional wind (advection) being the main driver for NLC occurrence above our site. Citation: Gerding, M., M. Kopp, P. Hoffmann, J. Höffner, and F.-J. Lübken (2013), Diurnal variations of midlatitude NLC parameters observed by daylight-capable lidar, and their relation to ambient parameters, Geophys. Res. Lett., 40, 6390–6394, doi:10.1002/2013GL057955.